WorldWideScience

Sample records for radiosensitive cancer patients

  1. Chromosomal radiosensitivity of prostate cancer patients

    International Nuclear Information System (INIS)

    McRobbie, M.L.; Riches, A.; Baxby, K.

    2003-01-01

    Full text: Radiosensitivity of peripheral blood lymphocytes from prostate cancer patients is being investigated using the G2 assay and the Cytokinesis Block Micronucleus(CBMN)assay. The G2 assay evaluates chromosomal damage caused by irradiating cells in the G2 phase of the cell cycle. The CBMN assay quantifies the post mitotic micronuclei, which are the expression of damage incurred during G0. An association between hypersensitivity to the chromosome damaging effects of ionising radiation and cancer predispostion has been demonstrated in a number of heritable conditions by using the aforementioned techniques. Recently, increased chromosomal radiosensitivity has been demonstrated in a significant proportion of patients with no obvious family history of malignancy. The aim of this study is to establish whether a group of prostatic carcinoma patients exists and if so whether there are any correlations between their G2 and G0 sensitivities. The study has shown there is no correlation between G2 and G0 sensitivity, confirming the general trend that individuals exhibiting chromosomal radiosensitivity are defective in only one mechanism and G2 and G0 sensitivity are largely independent. Current data indicates that there is an identifiable group of men within the prostate cancer population with increased chromosomal radiosensitivity. Using the G2 assay and the 90th percentile of the controls as a cut off point for sensitivity, no significant difference between the controls and the patient population has been found. However, using the CBMN assay and again the 90th percentile, approximately 11% of the control group are sensitive compared with approximately 40% of the carcinoma cases. The implications of this increased radiosensitivity are as yet unclear, but it is indicative of increased chromosomal fragility and therefore, possibly associated with malignant transformation. Hence, it may prove a useful tool in identifying individuals at increased risk of developing

  2. Chromosomal radiosensitivity in breast cancer patients and BRCA1 and 2 mutation carriers

    International Nuclear Information System (INIS)

    Vral, Anne

    2004-01-01

    Enhanced chromosomal radiosensitivity is observed in significant proportions of cancer patients. In breast cancer patients, this elevated sensitivity is confirmed in several independent studies with the G2 assay as well as with the GO micronucleus (MN) assay for peripheral blood lymphocytes (PBL). Enhanced chromosomal radiosensitivity is a common feature of sporadic breast cancer patients as well as breast cancer patients with a family history of the disease. Segregation analysis showed Mendelian heritability of chromosomal radiosensitivity. As mutations in the highly penetrant breast cancer predisposing genes, BRCA1 and 2, are only present in about 3-5 % of familial breast cancer patients, they cannot solely account for the high proportion of radiosensitive cases found among all breast cancer patients. A review on chromosomal radiosensitivity in BRCA1 and 2 mutation carriers shows that breast cancer patients with a BRCAl or 2 mutation are on the average more radiosensitive than healthy individuals, but not different from breast cancer patients without a BRCA mutation. The radiation response of healthy BRCA1/2 mutation carriers, on the contrary, is not significantly different from controls. Most studies performed on wild type and BRCA +/- EBV lymphoblastoid cell lines also could not demonstrate any differences in MN response between both groups. These findings suggest that mutations in BRCA 1 and 2 are not playing a major role in chromosomal radiosensitivity as measured by G2 and MN assay. The enhanced sensitivity observed in a substantial proportion of breast cancer patients, irrespective of a BRCA1/2 mutation or not, suggests that this feature may be related to the presence of other mutations in low penetrance breast cancer predisposing genes, which may be involved in the process of DNA damage. (author)

  3. ATM induction insufficiency in a radiosensitive breast-cancer patient

    International Nuclear Information System (INIS)

    Clarke, R.A.; Fang, Z.H.; Marr, P.J.; Kearsley, J.H.; Papadatos, G.; Lee, C.S.; University of Sydney, Camperdown, NSW

    2002-01-01

    ATM induction insufficiency in a radiosensitive breast-cancer patient The ataxia telangiectasia (A-T) gene (ATM) is a dominant breast cancer gene with tumour suppressor activity. ATM also regulates cellular sensitivity to ionising radiation (IR) presumably through its role as a facilitator of DNA repair. In normal cells and tissues the ATM protein is rapidly induced by IR to threshold/maximum levels. The kinase function of the ATM protein is also rapidly activated in response to IR. The fact that women carriers of ATM mutations can have an increased risk of developing breast cancer and that many sporadic breast tumours have reduced levels of the ATM protein broadens the scope of ATM's tumour suppressor within the breast. This report describes the downregulation of ATM protein levels in a radiosensitive breast cancer patient. Postinduction ATM levels were up to tenfold lower in the patient's fresh tissues compared to normal controls. These results might indicate a much broader role for ATM anomalies in breast cancer aetiology. Copyright (2002) Blackwell Science Pty Ltd

  4. Cytogenetic radiosensitivity of G0-lymphocytes of breast and esophageal cancer patients as determined by micronucleus assay

    International Nuclear Information System (INIS)

    Mozdarani, H.; Mansouri, Z.; Haeri, S.A.

    2005-01-01

    Enhanced chromosomal radiosensitivity is a feature of many cancer predisposition conditions, indicative of the important role of chromosomal alterations in carcinogenesis. In this study the cytokinesis-blocked micronucleous assay was used to compare the radiosensitivity of blood lymphocytes obtained from Iranian breast or esophageal cancer patients (n=50, n=16; respectively) with that of control individuals (n=40). For each sample, one thousand binucleate lymphocytes were analyzed before and after in vitro exposure to 3 Gy of γ rays. The radiation-induced frequency of micronucleus was significantly higher in the breast cancer group (261/1,000 binucleated cells) than in esophageal cancer group (241/1,000 binucleated cells, P<0.01) or in the control group (240/1,000 binucleated cells, P<0.01). The results indicate that breast cancer patients are more radiosensitive compared to normal healthy individuals or esophageal cancer patients. Increased radiosensitivity could be due to defects in DNA repair genes involved in breast cancer formation. Since patients with esophageal cancer did not show elevated radiosensitivity, it is assumed that the contribution of radiosensitivity-related genes to the development of esophageal cancer may be smaller than the contribution of those genes to breast cancer. (author)

  5. Chromosomal radiosensitivity in breast cancer patients with a known or putative genetic predisposition.

    LENUS (Irish Health Repository)

    Baeyens, A

    2002-12-02

    The chromosomal radiosensitivity of breast cancer patients with a known or putative genetic predisposition was investigated and compared to a group of healthy women. The chromosomal radiosensitivity was assessed with the G2 and the G0-micronucleus assay. For the G2 assay lymphocytes were irradiated in vitro with a dose of 0.4 Gy (60)Co gamma-rays after 71 h incubation, and chromatid breaks were scored in 50 metaphases. For the micronucleus assay lymphocytes were exposed in vitro to 3.5 Gy (60)Co gamma-rays at a high dose rate or low dose rate. 70 h post-irradiation cultures were arrested and micronuclei were scored in 1000 binucleate cells. The results demonstrated that the group of breast cancer patients with a known or putative genetic predisposition was on the average more radiosensitive than a population of healthy women, and this with the G2 as well as with the high dose rate and low dose rate micronucleus assay. With the G2 assay 43% of the patients were found to be radiosensitive. A higher proportion of the patients were radiosensitive with the micronucleus assay (45% with high dose rate and 61% with low dose rate). No correlation was found between the G2 and the G0-micronucleus chromosomal radiosensitivity. Out of the different subgroups considered, the group of the young breast cancer patients without family history showed the highest percentage of radiosensitive cases in the G2 (50%) as well as in the micronucleus assay (75-78%).

  6. Validation of a radiosensitivity molecular signature in breast cancer

    NARCIS (Netherlands)

    S.A. Eschrich (Steven); C. Fulp (Carl); Y. Pawitan (Yudi); J.A. Foekens (John); M. Smid (Marcel); J.W.M. Martens (John); M. Echevarria (Michelle); P.S. Kamath (Patrick); J.-H. Lee (Ji-Hyun); E.E. Harris (Eleanor); J. Bergh (Jonas); J.F. Torres-Roca (Javier)

    2012-01-01

    textabstractPurpose: Previously, we developed a radiosensitivity molecular signature [radiosensitivity index (RSI)] that was clinically validated in 3 independent datasets (rectal, esophageal, and head and neck) in 118 patients. Here, we test RSI in radiotherapy (RT)-treated breast cancer patients.

  7. Clinical studies on radiosensitization of cervical cancer by cisplatinum

    International Nuclear Information System (INIS)

    Yu Shiying; Chen Yuan; Xu Zhiqiang

    1993-01-01

    A prospective randomized clinical trial on the radiosensitizing effect of cisplatinum was carried out in 60 patients with cervical cancer, of whom 30 were given cisplatinum in combination with radiotherapy (radiosensitizing group) and the remaining 30 radiotherapy alone (control group). The results showed that the length of time of immediate CR and PR was shorter in the radiosensitizing group than in the control group. The sensitive enhancement ratio was 1.846. No toxicity was observed in the radiosensitizing group, and the treatment was well tolerated by the patients

  8. The development of genes associated with radiosensitivity of cervical cancer

    International Nuclear Information System (INIS)

    Li Hongyan; Chen Zhihua; He Guifang

    2007-01-01

    It has a good application prospect to predict effects of radiotherapy by examining radiosensitivity of patients with cervical cancers before their radiotherapy. Prediction of tumor cell radiosensitivity according to their level of gene expression and gene therapy to reverse radio-resistance prior to radiation on cervical cancers are heated researches on tumor therapy. The expression of some proliferation-related genes, apoptosis-related genes and hypoxia-related genes can inerease the radiosensitivity of cervical cancer. Microarray technology may have more direct applications to the study of biological pathway contributing to radiation resistance and may lead to development of alternative treatment modalities. (authors)

  9. The potential role of G2- but not of G0-radiosensitivity for predisposition of prostate cancer

    International Nuclear Information System (INIS)

    Borgmann, Kerstin; Raabe, Annette; Reuther, Sebastian; Szymczak, Silke; Schlomm, Thorsten; Isbarn, Hendrik; Gomolka, Maria; Busjahn, Andreas; Bonin, Michael; Ziegler, Andreas; Dikomey, Ekkehard

    2010-01-01

    Purpose: Comparing the chromosomal radiosensitivity of prostate cancer patients with that of healthy donors. Materials and methods: The study was performed on 81 prostate cancer patients characterised by a clinical stage of predominantly pT2c or pT3a and a median age of 67 years. As healthy donors 60 male monozygotic twin pairs were recruited with a median age of 28 years. Chromosomal radiosensitivity was measured using both G0- and G2-assay. Results: No difference between healthy donors and prostate cancer patients was detected concerning G0-radiosensitivity, since medians were similar (Hodges-Lehmann estimate: -0.05, 95% CI: -0.18-0.08, p = 0.4167). However, a pronounced difference was determined for G2-radiosensitivity with prostate cancer patients showing a significantly higher sensitivity compared to healthy donors (Hodges-Lehmann estimate: -0.41, 95% CI: -0.53 to -0.30, p = 1.75 -9 ). Using the 90% quantile of G2-radiosensitivity in healthy donors as a threshold for discrimination the fraction of prostate cancer patients with elevated radiosensitivity increased to 49%. Conclusion: G2-, but not G0-radiosensitivity is a promising marker for predisposition of prostate cancer.

  10. Targeting Mcl-1 for Radiosensitization of Pancreatic Cancers

    Directory of Open Access Journals (Sweden)

    Dongping Wei

    2015-02-01

    Full Text Available In order to identify targets whose inhibition may enhance the efficacy of chemoradiation in pancreatic cancer, we previously conducted an RNAi library screen of 8,800 genes. We identified Mcl-1 (myeloid cell leukemia-1, an anti-apoptotic member of the Bcl-2 family, as a target for sensitizing pancreatic cancer cells to chemoradiation. In the present study we investigated Mcl-1 inhibition by either genetic or pharmacological approaches as a radiosensitizing strategy in pancreatic cancer cells. Mcl-1 depletion by siRNA produced significant radiosensitization in BxPC-3 and Panc-1 cells in association with Caspase-3 activation and PARP cleavage, but only minimal radiosensitization in MiaPaCa-2 cells. We next tested the ability of the recently identified, selective, small molecule inhibitor of Mcl-1, UMI77, to radiosensitize in pancreatic cancer cells. UMI77 caused dissociation of Mcl-1 from the pro-apoptotic protein Bak and produced significant radiosensitization in BxPC-3 and Panc-1 cells, but minimal radiosensitization in MiaPaCa-2 cells. Radiosensitization by UMI77 was associated with Caspase-3 activation and PARP cleavage. Importantly, UMI77 did not radiosensitize normal small intestinal cells. In contrast, ABT-737, an established inhibitor of Bcl-2, Bcl-XL, and Bcl-w, failed to radiosensitize pancreatic cancer cells suggesting the unique importance of Mcl-1 relative to other Bcl-2 family members to radiation survival in pancreatic cancer cells. Taken together, these results validate Mcl-1 as a target for radiosensitization of pancreatic cancer cells and demonstrate the ability of small molecules which bind the canonical BH3 groove of Mcl-1, causing displacement of Mcl-1 from Bak, to selectively radiosensitize pancreatic cancer cells.

  11. The impact of complex chromosomal rearrangements on the detection of radiosensitivity in cancer patients

    International Nuclear Information System (INIS)

    Neubauer, Susann; Dunst, Juergen; Gebhart, Erich

    1997-01-01

    Background and purpose: Lymphocytes of a small fraction of cancer patients responded to in vitro irradiation with an extreme chromosomal reaction. A large portion of the observed chromosome aberrations were complex chromosomal rearrangements (CCR). The present study is an attempt to define the impact of CCR on the predictive detection of an intrinsic clinical radiosensitivity in cancer patients in more detail. Materials and methods: A three-colour 'FISH-painting' technique (chromosome in situ suppression (CISS) hybridization) was used for the detection of chromosomal rearrangements, induced by in vitro irradiation, in 81 samples of peripheral blood lymphocytes from 66 cancer patients. Thirty-three of those were assigned for radiation therapy, the others having just undergone radiation therapy. Seven healthy individuals served as controls. Results: CCRs are a very rare event in non-irradiated cells. Lymphocytes of patients who had just undergone therapeutic irradiation, however, not only exhibited high basic frequencies of CCR but also responded to in vitro irradiation with a more drastic increase of CCR than did the lymphocytes of non-exposed patients. A high inter-individual variability of the reaction to in vitro irradiation could be generally stated. The lymphocytes of patients with clinical signs of an outstanding radiosensitivity responded with an unusually high frequency of CCR. The total number of CCRs detected by CISS was found to be dependent on the interval from a previous radiation therapy and was slightly influenced by previous cytostatic therapy. Irrespective of these influences, patients with clinically defined radiation hypersensitivity were those with the highest radiosensitivity also in cytogenetic terms (including CCR). Conclusion: The successful use of FISH-painting for the detection of CCR, in addition to the general breakage frequency, highlights its suitability in the identification of individual hypersensitivity to ionizing radiation. The

  12. In vitro radiosensitivity of primary human fibroblasts. Lack of correlation with acute radiation toxicity in patients with head and neck cancer

    International Nuclear Information System (INIS)

    Rudat, Volker; Dietz, Andreas; Conradt, Christian; Weber, Klaus-Josef; Flentje, Michael

    1997-01-01

    Background and purpose: There is a considerable hope among clinicians and radiobiologists to detect genetically radiosensitive patients prior to radiotherapy. A predictive assay would enable adjustment of the total irradiation dose to the individual at a constant risk of normal tissue complications. In this prospective study, the clonogenic survival assay for primary human fibroblasts to determine radiosensitivity in vitro was evaluated and then correlated with clinically observed acute radiation reactions. Materials and methods: One hundred twenty-five independent survival experiments with primary fibroblasts derived from 63 biopsies from 55 cancer and non-cancer patients were performed. Results: A wide variation of cell survival between biopsies was detected. Statistical analysis revealed a highly significantly larger interindividual than intraindividual variation of SF2 values. However, a considerable scatter of SF2 values in repeated experiments was observed in individual cases. Age, gender, disease status (cancer patient, non-cancer patient) and origin of fibroblasts (skin, periodontal tissue) were demonstrated not to be statistically significant confounding factors on the intrinsic radiosensitivity in vitro. In a prospective study, no correlation of the SF2 and acute reactions in 25 patients with head and neck cancer treated with a primary accelerated radiochemotherapy was detected. Conclusion: Our data show that the clonogenic assay is able to distinguish between intrinsic radiosensitivities of primary human fibroblasts if a statistical approach is used but does not predict acute radiation toxicity

  13. Chromosomes, cancer and radiosensitivity

    International Nuclear Information System (INIS)

    Samouhos, E.

    1983-01-01

    Some specific chromosomal abnormalities are associated with certain cancers. The earliest description of such a specific association is the one of the Philadelphia chromosome and myelogenous leukemia (1960). Other congenital karyotype abnormalities are associated with specific cancers. Examples of these are Down's syndrome with leukemia and Klinefelter's syndrome with male breast cancer. Genetic diseases of increased chromosome breakage, or of defective chromosome repair, are associated with greatly increased cancer incidence. Three such diseases have been recognized: 1) Fanconi's anemia, associated with leukemias and lymphomas, 2) Bloom's syndrome, associated with acute leukemias and lymphosarcoma, and 3) ataxia telangiectasia, associated with Hodgkin's disease, leukemia, and lymphosarcomas. Ten percent of individuals with ataxia telangiectasia will develop one of these neoplasms. Individuals with certain of these syndromes display an unusually high radiosensitivity. Radiation therapy for cancers has been fatal in patients who received as low as 3000 rad. This remarkable radiosensitivity has been quantitated in cell cultures from such cases. Evidence suggests that the apparent sensitivity may reflect subnormal ability to repair radiation damage. The rapid proliferation of information in this field stems from the interdigitation of many disciplines and specialties, including cytogenetics, cell biology, molecular biology, epidemiology, radiobiology, and several others. This paper is intended for clinicians; it presents a structured analytic scheme for correlating and classifying this multidisciplinary information as it becomes available

  14. Individual radiosensitivity measured with lymphocytes can be used to predict the risk of fibrosis after radiotherapy of breast cancer patients

    International Nuclear Information System (INIS)

    Hoeller, U.; Borgmann, K.; Alberti, W.; Dikomey, E.

    2003-01-01

    To analyse the relationship of individual cellular radiosensitivity and fibrosis after breast conserving therapy. A new model was used describing the percentage of patients developing fibrosis per year per patients at risk . In a retrospective study, 86 patients were included, who had undergone breast conserving surgery and irradiation of the breast with a median dose of 55 Gy (54-55Gy), 2.5 Gy/fraction (n=57) or 2 Gy/fraction (n=29). Median age was 62 years (range: 44-86) and median follow up was 7.5 years (range 5-16). Patients were examined for fibrosis according to the LENT/SOMA score. For analysis, fibrosis was classified as none (G0-1) or present (G2-3). The time to complete development of fibrosis was determined by analysis of yearly mammograms. Individual cellular radiosensitivity was determined by scoring lethal chromosomal aberrations in in vitro irradiated (6 Gy) lymphocytes using metaphase technique. Patients with low/intermediate cellular radiosensitivity were compared with patients with high cellular radiosensitivity with actuarial methods. Ten patients developed fibrosis at 1-8 years after radiotherapy. Individual cellular radiosensitivity was described by normal distribution of lethal chromosomal aberrations, average 5.47 lethal aberrations per cell (standard deviation 0.71). Cellular radiosensitivity was defined as low/intermediate (le 6.18 lethal aberrations) in 73 patients and as high (> 6.18 lethal aberrations ) in 13 patients. In both groups the actuarial rate of fibrosis-free patients declined exponentially with time after radiotherapy. Patients with high cellular radiosensitivity showed a 2.3 fold higher annual rate for fibrosis than patients with intermediate and low radiosensitivity (3.6±0.1 vs. 1.6±0.3). In breast cancer patients, high individual cellular radiosensitivity as determined by the number of lethal chromosome aberrations in in vitro irradiated lymphocytes was correlated with an enhanced annual rate of fibrosis

  15. Correlating telomere length and radiosensitivity in cancer patients

    International Nuclear Information System (INIS)

    Sprung, C.N.; Davey, D.S.P.; McKay, M.J.

    2003-01-01

    Approximately three percent of cancer patients suffer from significant side effects in normal tissue exposed to ionising radiation during radiotherapy (RT). Although RT is an effective therapy for cancer treatment, the treatment dose intensity is generally restricted to minimize the incidence of these severe reactions. This imposes tumour control limitations on most patients. A major goal of radiation biology research is to develop efficient predictive assays that could identify these hyper-radiosensitive (hRS) individuals prior to treatment. This predictive ability would enable the individualisation of RT doses, which should result in improvement of tumour control rates and a reduction in the incidence of RT side effects. Recent studies have reported a correlation between cellular and organismal RS and shortened telomeres. Interestingly, a number of DNA repair proteins have been found to be associated with telomeres. Additionally, individuals with cancer-proneness and RS syndromes, such as ataxia telangiectasia and Fanconi anemia, have shortened telomeres. In animal models, mutations in DNA repair genes such as Ku, has resulted in shortened telomeres. We have a unique bank of blood samples and lymphoblastoid cell lines (LCLs) from over 50 hRS patients. We have used traditional methods of telomere length assessment and a clinically relevant method, flow cytometry fluorescence in situ hybridisation (flow-FISH) to determine the telomere length in both LCLs and peripheral blood mononuclear cells from the hRS patients. Results from the screening of these samples will be presented. If clinical hRS can be correlated with shortened telomeres in some patients, flow-FISH may have utility as part of a pre-treatment hRS assay for use in the clinic

  16. Breast-conservation treatment without any surgical procedure using new enzyme-targeting radiosensitization treatment for aged and/or op. refused patients with breast cancer

    International Nuclear Information System (INIS)

    Ogawa, Yasuhiro; Kubota, Kei; Miyatake, Kana

    2008-01-01

    We developed a new radiosensitizer containing hydrogen peroxide and sodium hyaluronate for topical tumor injection for various types of tumors, and the method was named KORTUC II (Kochi Oxydol-Radiation Therapy for Unresectable Carcinomas, Type II). KORTUC II trial was accepted by our local ethical committee concerning of the injection for advanced skin cancer, advanced bone/soft tissue malignant neoplasms, breast cancer of op refused or aged patients, and metastatic lymph nodes. Concerning breast cancer, ten patients were enrolled in the KORTUC II trial upon fully informed consent. All of them showed clinically complete response by the new enzyme-targeting radiosensitization treatment (KORTUC II) without any severe complications excluding mild dermatitis (grade I). Nine of the 10 patients have so far shown neither local recurrence nor distant metastasis, and the mean follow-up period at the end of December 2007 was still short and approximately 12 months. Especially for patients with breast cancer, breast-conservation treatment without any surgical procedure can be performed by using our new radiosensitizer for topical injection into the tumor tissue. (author)

  17. Assessment of individual radiosensitivity in human lymphocytes of cancer patients and its correlation with adverse side effects to radiation therapy

    International Nuclear Information System (INIS)

    Di Giorgio, Marina; Vallerga, Maria B.; Taja, Maria R.; Sardi, M.; Busto, E.; Roth, B.; Menendez, P.; Bonomi, M.; Mairal, L.

    2003-01-01

    Background and purpose: Individual radiosensitivity is an inherent characteristic, associated with an increased reaction to ionizing radiation on the human body. Biological endpoints such as clonogenic survival, chromosome aberration formation and repair capacity of radiation-induced damage have been applied to evaluate individual radiosensitivity in vitro. 5%-7% of cancer patients develop adverse side effects to radiation therapy in normal tissues within the treatment field, which are referred as 'clinical radiation reactions' and include acute effects, late effects and cancer induction. It has been hypothesized that the occurrence and severity of these reactions are mainly influenced by genetic susceptibility to radiation. Additionally, the nature of the genetic disorders associated with hypersensitivity to radiotherapy suggests that DNA repair mechanisms are involved. Consequently, the characterization of DNA repair in lymphocytes through cytokinesis blocked micronucleus (MN) and alkaline single-cell micro gel electrophoresis (comet) assays could be suitable approaches to evaluate individual radiosensitivity in vitro. The MN assay is an established cytogenetic technique to evaluate intrinsic cell radiosensitivity in tumor cells and lymphocytes; comet assay is a sensitive and rapid method for measuring DNA damage and repair in individual cells. The aims of this study were: 1) To assess the in vitro radiosensitivity of peripheral blood lymphocytes from two groups of cancer patients (retrospectively and prospectively studied), using MN and comet assays, in comparison with the observed clinical response; and 2) To test the predictive potential of both techniques. Materials and methods: 38 cancer patients receiving radiation therapy were enrolled in this study. The tumor sites were: head and neck (n 25) and cervix (n = 13). Nineteen patients were evaluated about 6-18 month after radiotherapy (retrospective group) and 19 patients were evaluated prior, mid-way and on

  18. Radiosensitizers in cervical cancer. Cisplatin and beyond

    International Nuclear Information System (INIS)

    Candelaria, Myrna; Garcia-Arias, Alicia; Cetina, Lucely; Dueñas-Gonzalez, Alfonso

    2006-01-01

    Cervical cancer continues to be a significant health burden worldwide. Globally, the majority of cancers are locally advanced at diagnosis; hence, radiation remains the most frequently used therapeutical modality. Currently, the value of adding cisplatin or cisplatin-based chemotherapy to radiation for treatment of locally advanced cervical cancer is strongly supported by randomized studies and meta-analyses. Nevertheless, despite these significant achievements, therapeutic results are far from optimal; thus, novel therapies need to be assayed. A strategy currently being investigated is the use of newer radiosensitizers alone or in combination with platinum compounds. In the present work, we present preclinical information on known and newer cytotoxic agents as radiosensitizers on cervical cancer models, as well as the clinical information emanating from early phase trials that incorporate them to the cervical cancer management. In addition, we present the perspectives on the combined approach of radiation therapy and molecular target-based drugs with proven radiosensitizing capacity

  19. Clinical and Functional Assays of Radiosensitivity and Radiation-Induced Second Cancer

    Directory of Open Access Journals (Sweden)

    Mohammad Habash

    2017-10-01

    Full Text Available Whilst the near instantaneous physical interaction of radiation energy with living cells leaves little opportunity for inter-individual variation in the initial yield of DNA damage, all the downstream processes in how damage is recognized, repaired or resolved and therefore the ultimate fate of cells can vary across the population. In the clinic, this variability is observed most readily as rare extreme sensitivity to radiotherapy with acute and late tissue toxic reactions. Though some radiosensitivity can be anticipated in individuals with known genetic predispositions manifest through recognizable phenotypes and clinical presentations, others exhibit unexpected radiosensitivity which nevertheless has an underlying genetic cause. Currently, functional assays for cellular radiosensitivity represent a strategy to identify patients with potential radiosensitivity before radiotherapy begins, without needing to discover or evaluate the impact of the precise genetic determinants. Yet, some of the genes responsible for extreme radiosensitivity would also be expected to confer susceptibility to radiation-induced cancer, which can be considered another late adverse event associated with radiotherapy. Here, the utility of functional assays of radiosensitivity for identifying individuals susceptible to radiotherapy-induced second cancer is discussed, considering both the common mechanisms and important differences between stochastic radiation carcinogenesis and the range of deterministic acute and late toxic effects of radiotherapy.

  20. Lung cancer radiosensitization by CMNa in vitro and in vivo

    International Nuclear Information System (INIS)

    Zhang Xia; Ouyang Xienong; Ji Hongbing; Chen Zhonghua; Yang Rujun

    2005-01-01

    Objective: To probe into the radiosensitization effect of CMNa on lung tumor cell lines after γ-irradiation combined with γ-knife to treat patients suffering from lung cancer. Methods: 1. Cells of small cell lung cancer cell line NCI-H446 and non-small cell lung cancer cell line NCI-H596 irradiated with 60 Co γ-rays combined with or without CMNa were counted using trypan blue exclusion methods, and cell survival rate curves were depicted. 2. Patients suffering from lung cancer at different clinical stages were treated using γ-knife combined with or without CMNa, and the curative effect was evaluated 6 weeks after one cycle of treatment. Results: CMNa could significantly increase the sensitivity of lung cancer cell lines to γ-irradiation. Curative effect increased significantly by γ-knife treatment combined with CMNa i. e., the CR+PR rates for these two groups were 47.22% and 37.67% separately (P 0.05). Conclusion: CMNa could significantly increase the radiation sensitivity of lung cancer cell line cells in vitro and tumors in vivo, therefore, it could be used as a radiosensitization agent in clinical treatment of lung cancer. (authors)

  1. Normal tissue adverse side effects in radiotherapy cancer patients and applicability of predictive radiosensitivity tests for new radiation treatment decision

    International Nuclear Information System (INIS)

    Di Giorgio, Marina; Vallerga, Maria B.; Radl, Analia; Sardi, Mabel

    2008-01-01

    Full text: Around 5 % -7 % of cancer patients develop adverse side effects, which include acute effects, late effects and cancer induction to radiation therapy in normal tissues in the treatment field. Such effects are of particular interest as the cancer patient population that reaches prolonged survival has increased with the improvements in cancer therapy and health care. These adverse reactions are mainly influenced by deficiencies in DNA repair pathways. However, tissue response to IR could be modified by several treatment- and patient- related factors. Numerous studies have been carried out to evaluate the correlation between clinical and cellular radiosensitivity, by in vitro tests. Previous own studies, characterizing DNA repair capacity in peripheral lymphocytes of cancer patients through cytokinesis blocked micronucleus test and alkaline single-cell microgel electrophoresis (comet), indicated that such assays correlated with the clinical radiation signs of radiosensitivity and showed the predictive potential of both techniques in the identification of radiosensitivity subgroups. In this paper, retrospective studies are conducted in 10 representative cases, which had developed acute or late toxicity in previous treatments and at present require new radiation treatments due to secondary malignancies or recurrence. Samples were in vitro irradiated with 2 Gy. MN data were analyzed comparing expected MN frequencies with values observed after in vitro irradiation. DNA repair capacity was evaluated through comet assay for initial damage and after specific times of repair (0-120 minutes). Captured images were analyzed by CASP image analysis software. Repair capacity was quantified by the Olive tail moment. Weibull alpha parameter was applied to describe DNA damage at the different evaluated repair times after in vitro irradiation and fitted by a mono-exponential model to describe the kinetic profile. In every evaluated patient a correlation between mean half

  2. Normal tissue adverse side effects in radiotherapy cancer patients and applicability of predictive radiosensitivity tests for new radiation treatment decision

    International Nuclear Information System (INIS)

    Di Giorgio, M.; Vallerga, M.B.; Radl, A.; Sardi, M.

    2011-01-01

    Around 5%-7% of cancer patients develop adverse side effects, which include acute effects, late effects and cancer induction to radiation therapy in normal tissues in the treatment field. Such effects are of particular interest as the cancer patient population that reaches prolonged survival has increased with the improvements in cancer therapy and health care. These adverse reactions are mainly influenced by deficiencies in DNA repair pathways. However, tissue response to IR could be modified by several treatment- and patient- related factors. Numerous studies have been carried out to evaluate the correlation between clinical and cellular radiosensitivity, by in vitro tests. Previous own studies, characterizing DNA repair capacity in peripheral lymphocytes of cancer patients through cytokinesis blocked micronucleus test and alkaline single-cell microgel electrophoresis (comet), indicated that such assays correlated with the clinical radiation signs of radiosensitivity and showed the predictive potential of both techniques in the identification of radiosensitivity subgroups. In this paper, retrospective studies are conducted in 10 representative cases, which had developed acute or late toxicity in previous treatments and at present require new radiation treatments due to secondary malignancies or recurrence. Samples were in vitro irradiated with 2 Gy. MN data were analyzed comparing expected MN frequencies with values observed after in vitro irradiation. DNA repair capacity was evaluated through comet assay for initial damage and after specific times of repair (0-120 minutes). Captured images were analyzed by CASP image analysis software. Repair capacity was quantified by the Olive tail moment. Weibull alpha parameter was applied to describe DNA damage at the different evaluated repair times after in vitro irradiation and fitted by a mono-exponential model to describe the kinetic profile. In every evaluated patient a correlation between mean half-time (T1/2) and

  3. Development of novel radiosensitizers for cancer therapy

    CERN Document Server

    Akamatsu, K

    2002-01-01

    The novel radiosensitizers for cancer therapy, which have some atoms with large X-ray absorption cross sections, were synthesized. The chemical and radiation (X-rays, W target, 100kVp) toxicities and the radiosensitivities to LS-180 human colon adenocarcinoma cells were also evaluated. 2,3,4,5,6-pentabromobenzylalcohol (PBBA) derivatives were not radiosensitive even around the maximum concentration. On the other hand, the hydrophilic sodium 2,4,6-triiodobenzoate (STIB) indicated meaningful radiosensitivity to the cells. Moreover, the membrane-specific radiosensitizers, cetyl fluorescein isthiocyanate (cetyl FITC), cetyl eosin isothiocyanate (cetyl br-FITC), cetyl erythrosin isothiocyanate (cetyl I-FITC), which aim for the membrane damage by X-ray photoabsorption on the target atoms, were localized in the plasma membrane. As the results of the colony formation assay, it was found that both cetyl FITC are similarly radiosensitive. In this report, we demonstrate the synthetic methods of the radiosensitizers, the...

  4. Normal cellular radiosensitivity in an adult Fanconi anaemia patient with marked clinical radiosensitivity

    International Nuclear Information System (INIS)

    Marcou, Yiola; D'Andrea, Andrew; Jeggo, Penelope A.; Plowman, Piers N.

    2001-01-01

    Background: Fanconi anaemia is a rare disease associated with cellular sensitivity to chemicals (e.g. mitomycin C and diepoxybutane); variable but mild cellular radiosensitivity has also been reported. Materials and methods: A 32-year-old patient with Fanconi anaemia and tonsillar carcinoma, treated by radiotherapy, was found to exhibit profound clinical radiosensitivity. Confluent, ulcerating oropharyngeal mucositis developed after a conventionally fractionated dose of 34 Gy and healing was incomplete by 2 months after cessation of therapy. Results: Cellular radiosensitivity assays and RPLD studies from this patient did not suggest any major detectable radiosensitivity. Conclusion: There is a discrepancy between the observed clinical radiosensitivity and the usual 'predictive' radiosensitivity assays in this patient with Fanconi anaemia

  5. Review of our histological criteria for the radiosensitivity of uterine cervical cancer

    International Nuclear Information System (INIS)

    Tsukahara, Yoshiharu; Shiozawa, Kyuyo; Tsukamoto, Takashi; Sonehara, Morio; Noguchi, Hiroshi

    1975-01-01

    The determination of radiosensitiveness based on 111 operated specimens after test irradiation of 1000R was compared with that based on 64 specimens which had received biopsies seven days after irradiation. It was concluded that the determination of radiosensitiveness by local biopsy could be applied to practical use. The results of this study are listed as follows: (1) Radiosensitivity exists within tumor cells themselves before irradiation, while radiosensitiveness is a complicated change in which some reaction on the host side added to degenerated tumor cells. (2) In the determination of radio-sensitiveness, there was a good accordance of 85% between biopsies and removed specimens. (3) The followings are findings of favorable radiosensitiveness based on the removed specimens; (a) neutrocyte infiltration within cancer nests, (b) lysis of cancer nests, (c) destruction of fundus of cancer nests, (d) damages of advanced sites of cancer infiltration, (e) damages of chromatin. As unfavorable findings, (f) mitosis, (g) abundant viable cells. (4) Various histological findings within cancer nests and variation of radiosensitiveness according to various regions of the tumor often cause a discord with biopsies. (5) Many specimens which show the intermediate histological type in maturation before irradiation indicate favorable radiosensitiveness. Even if they belong to the intermediate type, the specimens in which the issued histological findings are mixed show mostly unfavorable radiosensitiveness. (6) Removed specimens can be expressed in indices of radiosensitiveness. (Ichikawa, K.)

  6. Lethal outcome after pelvic salvage radiotherapy in a patient with prostate cancer due to increased radiosensitivity. Case report and literature review

    International Nuclear Information System (INIS)

    Fahrig, Antje; Koch, T.; Lenhart, M.; Rieckmann, P.; Fietkau, R.; Distel, Luitpold; Schuster, B.

    2018-01-01

    In general, late side effects after salvage radiotherapy (RT) for prostate cancer are below 10%. Patients with impaired DNA repair ability and genetic instability can have significantly increased reactions after RT. We present a patient who experienced severe side effects after additive RT for prostate cancer and died from the complications 25 months after RT. Imaging (MR) is shown as well as three-color fluorescence in situ hybridization. The blood sample testing revealed that radiosensitivity was increased by 35-55%. We undertook a review of the literature to give an overview over the tests established that are currently considered useful. This case highlights that the identification of patients with increased radiosensitivity is an important task in radiation protection. Groups of patients who should be screened have to be found and corresponding research facilities have to be set up. (orig.) [de

  7. Chromosomal radiosensitivity, cancer predisposition and response to radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Scott, D. [Christie Hospital, Manchester (United Kingdom). Paterson Inst. for Cancer Research

    2000-05-01

    Aim: This paper briefly summarizes the research on this topic, undertaken in the Department of Cancer Genetics, Paterson Institute for Cancer Research, Manchester, England, over the previous 6 years. We have investigated the possible role of radiosensitivity as a marker of cancer predisposition and response to radiotherapy in the general population. Results: We found that 42% (57/135) of breast cancer patients exhibit chromosomal radiosensitivity when lymphocytes are irradiated in the G{sub 2} phase of the cell cycle, compared with 6% (6/105) of healthy controls. These figures are much higher than the estimated frequencies of carriers of the ataxia-telangiectasia gene (heterozygotes) amongst breast cancer patients (<5%) and control (0.5%). We have also obtained evidence of heritability of G{sub 2} sensitivity by studying relatives of breast cancer cases. The pattern of inheritance is relatively simple and attributable to 1 or 2 genes segregating in each family. In a prospective study of 123 breast cancer patients, 9 (7%) had severe acute reactions to radiotherapy and their mean G{sub 2} sensitivity was significantly greater (p=0.001) than that of the remaining patients. In 16 patients with adverse acute reactions we found no mutations of the ataxia-telangiectasia gene (ATM). Using another chromosomal assay (micronucleus induction in G{sub 0} lymphocytes) we found that the mean radiosensitivity of patients with severe late reactions was higher than that of normal reactors. For example, 8 patients with severe fibrosis were more sensitive (p=0.055) than 39 patients with a normal response. However, the discriminatory power of these chromosomal assays is too low for them to be used alone in a clinical setting. Conclusion: Our results provide good evidence that genes other than ATM, that confer chromosomal radiosensitivity, are involved in low penetrance predisposition to breast cancer in a high proportion of cases and contribute to adverse reactions after radiotherapy

  8. Analysis of the individual radio sensitivity of breast cancer patients

    International Nuclear Information System (INIS)

    Auer, Judith

    2013-01-01

    Individual radiosensitivity has a crucial impact on radiotherapy related side effects. A prediction of individual radiosensitivity could avoid these side effects. Our aim was to study a breast cancer collective for its variation of individual radiosensitivity. Peripheral blood samples were obtained from 129 individuals. 67 breast cancer patients and 62 healthy and age matched individuals were looked at and their individual radiosensitivity was estimated by a 3-color Fluorescence in situ hybridization approach. Blood samples were obtained (i) before starting adjuvant radiotherapy and were in vitro irradiated by 2 Gy; (ii) after 5 single doses of 1.8 Gy and after 72 h had elapsed. DNA of lymphocytes was probed with whole chromosome painting for chromosomes 1, 2 and 4. The rate of breaks per metaphase was analyzed and used as a predictor of individual radiosensitivity. Breast cancer patients were distinctly more radio-sensitive compared to healthy controls. Additionally the distribution of the cancer patients' radiosensitivity was broader. A subgroup of 9 rather radio-sensitive and 9 rather radio-resistant patients was identified. A subgroup of patients aged between 40 and 50 was distinctly more radio-sensitive than younger or older patients. The in vivo irradiation approach was not applicable to detect individual radiosensitivity. In the breast cancer collective a distinctly resistant and sensitive subgroup is identified, which could be subject for treatment adjustment. Especially in the range of age 40 to 50 patients have an increased radiosensitivity. An in vivo irradiation in a breast cancer collective is not suitable to estimate individual radiosensitivity due to a low deposed dose.

  9. Preliminary screening of the radiosensitivity-associated genes on colorectal cancer

    International Nuclear Information System (INIS)

    Xing Chungen; Yang Xiaodong; Zhou Liying; Wu Yongyou; Jiang Yinfen; Dai Hong; Lv Xiaodong; Gong Wei

    2007-01-01

    The screening of radiosensitive genes of human colorectal cancer was made by gene chip. Two human colorectal cancer cell lines LOVO and SW480 were cultivated and the total RNA was extracted from at least lxl0 7 cells. Then the gene expression profiling was performed by HG-U133 Plus 2.0 Array and the difference of gene expression has been analyzed. The results shows that there are 16882 genes expressed in LOVO cell and 17114 genes expressed in SW480 cell through gene expression profiling. It has been found that the genes with 2-fold expressed differentially include 908 genes up-regulated and 1312 genes down-regulated. The same genes, such as Fas and NFkB which is up-regulated, Caspas6, and RAD21 which is down-regulated, have been proved to be related to radiosensitivity. The genes with high expression level including CEACAM5, THBS1, SERPINE2, ARL7, HPGD in LOVO cell may also be related to the radiosensitivity. And the genes with high expression level including SCD, NQ01, LYZ, KRT20, ATP1B1 in SW480 cell may be related to the radioresistance of human colorectal cancer. It could be concluded that the radiosensitivity of colorectal cancer can be reflected from gene and protein expression level. And gene expression profiling is a fast and sensitive tool to predict the radiosensitivity and screen radiosensitive genes of colorectal cancer. (authors)

  10. Genetic components for radiosensitivity. Gene expression in radiosensitive monocygotic twins. Final report

    International Nuclear Information System (INIS)

    Dikomey, Ekkehard

    2012-01-01

    The underlying hypothesis of this project was that the variation of individual radiosensitivity is determined by the different expression of single gens. This concept was tested using 60 monozygotic twin pairs, followed by an evaluation with 80 prostate cancer patients. Radiosensitivity was assessed for both G0- as well as G2-phase using chromosomal assays. G0- radiosensitivity is determined by lethal chromosomal aberrations and reflects the individual amount of cell killing, while G2-sensitivity is determined by chromatid breaks and is taken as an indicator of individual cancer risk. For both populations, G0- and G2-radiosensitivity are characterized by substantial variation with a CV of 11 and 14% or 27 and 21%, respectively. While the mean G0-sensitivity is the same for both populations, there is a slight difference for G2. The slightly higher value of G2-sensitivity found for prostate cancer patients might result from the higher age of this group. For both populations gene expression profiles were determined using the Affymetrix chip HG-U133+2.0. Overall gene expression was characterized by a huge variation covering more than four decades. However, for single genes, expression showed little variation with CV generally ranging only between 2 and 8%. Analysis of data using several different methods revealed that variation of both G0- as well as G2-radiosensitivity cannot be ascribed to the different expression of single genes. For twins, random forests can be used to identify 8 to 10 genes than are relevant either for G0- or G2-radiosensitivity. However, these genes cannot be confirmed by an evaluation with 80 prostate cancer patients. This finding clearly demonstrates that the hypothesis, due to which variation of individual radiosensitivity is caused by different expression of single genes, has to be rejected. It appears more likely that this parameter is determined by complex interactions of several genes in functional networks. (orig.)

  11. Metformin enhances radiosensitivity via inhibition of DNA repair pathway in colorectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Youn Kyoung; Kim, Mi Sook; Lee, Ji Young; Song, Kyung Hee; Choi, Kyul; Kim, Eun Ho; Ha, Hun Joo [Ewha Womans University, Seoul (Korea, Republic of)

    2014-04-15

    In this study, we provide a scientific rationale for the clinical application of metformin as a radiosensitizer in colorectal cancer. Colorectal cancer (CRC) is the third most common cancer in men and the second most common cancer in women worldwide. Currently, it is one of the commonest chemoradiotherapy worked better than the radiotherapy or chemotherapy in colorectal cancer. To enhance radiosensitivity of tumor cells for chemoradiotherapy, it is to use potential anticancer agents that act as radiosensitizers. Metformin, one of the most widely used antidiabetic drugs, has recently been associated with potential antitumorigenic effects. Our data shows that metformin combined with radiation enhances the efficacy of radiotherapy and down-regulates DNA repair proteins. Therefore, we provides a scientific rationale for the clinical application of metformin as a radiosensitizer in colorectal cancer.

  12. Metformin enhances radiosensitivity via inhibition of DNA repair pathway in colorectal cancer

    International Nuclear Information System (INIS)

    Jeong, Youn Kyoung; Kim, Mi Sook; Lee, Ji Young; Song, Kyung Hee; Choi, Kyul; Kim, Eun Ho; Ha, Hun Joo

    2014-01-01

    In this study, we provide a scientific rationale for the clinical application of metformin as a radiosensitizer in colorectal cancer. Colorectal cancer (CRC) is the third most common cancer in men and the second most common cancer in women worldwide. Currently, it is one of the commonest chemoradiotherapy worked better than the radiotherapy or chemotherapy in colorectal cancer. To enhance radiosensitivity of tumor cells for chemoradiotherapy, it is to use potential anticancer agents that act as radiosensitizers. Metformin, one of the most widely used antidiabetic drugs, has recently been associated with potential antitumorigenic effects. Our data shows that metformin combined with radiation enhances the efficacy of radiotherapy and down-regulates DNA repair proteins. Therefore, we provides a scientific rationale for the clinical application of metformin as a radiosensitizer in colorectal cancer

  13. G{sub 2} radiosensitivity of cells derived from cancer-prone individuals

    Energy Technology Data Exchange (ETDEWEB)

    Darroudi, F.; Vyas, R.C.; Vermeulen, S.; Natarajan, A.T. [J.A. Cohen Institute of Radiopathology and Radiation Protection, Interuniversity Institute, Leiden (Netherlands)

    1995-04-01

    The potential of enhanced chromatid damage, observed after X-irradiation of G{sub 2} phase, has been used to detect individuals genetically predisposed to cancer, utilising fibroblasts/lymphocytes from these patients as well as fibroblasts derived from human tumours. Fibroblasts and/or lymphocyte samples of two autosomal recessive syndromes (xeroderma pigmentosum (XP), Fanconi`s anaemia (FA)) and one congenital or acquired disorder, aplastic anaemia (AA), were employed for the G{sub 2} radiosensitivity assay. In addition, we have estimated the frequencies of spontaneously occurring chromosomal aberrations as well as G{sub 2} radiosensitivity of eight samples of fibroblasts/fibroblast-like cells (two normal, two colorectal carcinoma, two Wilms` tumour, one retinoblastoma and one polyposis coli), and three samples of lymphocytes (two normal and one from a lymphoma patient). The results obtained indicate that there were no differences between fibroblast cells derived from patients or tumours, except FA patients, in the frequency of spontaneously occurring chromosomal aberrations when compared to normal cells. Following X-irradiation we did not observe any significantly increased G{sub 2} radiosensitivity in FA and XP cells. Lymphocytes from AA and lymphoma patients, and all tumour cell lines except retinoblastoma, responded with increased frequencies of aberrations following G{sub 2} X-irradiation in comparison to cells derived from normal individuals. In our hands, the G{sub 2} sensitivity assay could not always discriminate cells from cancer-prone individuals from those of controls.

  14. Chromosomal radiosensitivity in Breast Cancer Patients with Different Tumor size: In vitro and In vivo Assessment

    International Nuclear Information System (INIS)

    El-Habit, O.H.

    2003-01-01

    Chromosomal radiosensitivity of normal tissues from breast cancer patients has been used for detection of cancer prone individuals. Interindividual variation among breast cancer patients and cancer-prone individuals is, however, not satisfactorily explained. In this study the type of tumor and its degree of progression is addressed to find out its effect on the variability produced. Three groups of breast cancer patients with different tumor sizes; I, II and III were used in this investigation. The first group of 12 patients with tumor grade I, the second group comprised 15 patients of tumor grade II and a third group of 13 patients of tumor grade III. A fourth control group of 14 normal healthy individuals of the same age group were also used. Blood samples were withdrawn before starting radiotherapy treatment. In vitro irradiation of blood with 2.0, 4.0 or 6.0 Gy, and blood culture was set up at 37 0C for 54 hr. Different types of chromosomal aberrations (dicentrics, rings, breaks, fragments and gaps) were scored. Another set of irradiated cultures were set up for assay of micronucleated binucleate lymphocytes treated with cytochalasin B. Blood samples were also obtained from breast cancer patients 24 hr

  15. Genetic variations in DNA repair genes, radiosensitivity to cancer and susceptibility to acute tissue reactions in radiotherapy-treated cancer patients

    International Nuclear Information System (INIS)

    Chistiakov, Dimitry A.; Voronova, Natalia V.; Chistiakov, Pavel A.

    2008-01-01

    Ionizing radiation is a well established carcinogen for human cells. At low doses, radiation exposure mainly results in generation of double strand breaks (DSBs). Radiation-related DSBs could be directly linked to the formation of chromosomal rearrangements as has been proven for radiation-induced thyroid tumors. Repair of DSBs presumably involves two main pathways, non-homologous end joining (NHEJ) and homologous recombination (HR). A number of known inherited syndromes, such as ataxia telangiectasia, ataxia-telangiectasia like-disorder, radiosensitive severe combined immunodeficiency, Nijmegen breakage syndrome, and LIG4 deficiency are associated with increased radiosensitivity and/or cancer risk. Many of them are caused by mutations in DNA repair genes. Recent studies also suggest that variations in the DNA repair capacity in the general population may influence cancer susceptibility. In this paper, we summarize the current status of DNA repair proteins as potential targets for radiation-induced cancer risk. We will focus on genetic alterations in genes involved in HR- and NHEJ-mediated repair of DSBs, which could influence predisposition to radiation-related cancer and thereby explain interindividual differences in radiosensitivity or radioresistance in a general population

  16. Genetic variations in DNA repair genes, radiosensitivity to cancer and susceptibility to acute tissue reactions in radiotherapy-treated cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Chistiakov, Dimitry A. (Dept. of Pathology, Univ. of Pittsburgh, Pittsburgh (US)); Voronova, Natalia V. (Dept. of Molecular Diagnostics, National Research Center GosNIIgenetika, Moscow (RU)); Chistiakov, Pavel A. (Dept. of Radiology, Cancer Research Center, Moscow (RU))

    2008-06-15

    Ionizing radiation is a well established carcinogen for human cells. At low doses, radiation exposure mainly results in generation of double strand breaks (DSBs). Radiation-related DSBs could be directly linked to the formation of chromosomal rearrangements as has been proven for radiation-induced thyroid tumors. Repair of DSBs presumably involves two main pathways, non-homologous end joining (NHEJ) and homologous recombination (HR). A number of known inherited syndromes, such as ataxia telangiectasia, ataxia-telangiectasia like-disorder, radiosensitive severe combined immunodeficiency, Nijmegen breakage syndrome, and LIG4 deficiency are associated with increased radiosensitivity and/or cancer risk. Many of them are caused by mutations in DNA repair genes. Recent studies also suggest that variations in the DNA repair capacity in the general population may influence cancer susceptibility. In this paper, we summarize the current status of DNA repair proteins as potential targets for radiation-induced cancer risk. We will focus on genetic alterations in genes involved in HR- and NHEJ-mediated repair of DSBs, which could influence predisposition to radiation-related cancer and thereby explain interindividual differences in radiosensitivity or radioresistance in a general population

  17. Validation of a Radiosensitivity Molecular Signature in Breast Cancer

    Science.gov (United States)

    Eschrich, Steven A.; Fulp, William J.; Pawitan, Yudi; Foekens, John A.; Smid, Marcel; Martens, John W. M.; Echevarria, Michelle; Kamath, Vidya; Lee, Ji-Hyun; Harris, Eleanor E.; Bergh, Jonas; Torres-Roca, Javier F.

    2014-01-01

    Purpose Previously, we developed a radiosensitivity molecular signature (RSI) that was clinically-validated in three independent datasets (rectal, esophageal, head and neck) in 118 patients. Here, we test RSI in radiotherapy (RT) treated breast cancer patients. Experimental Design RSI was tested in two previously published breast cancer datasets. Patients were treated at the Karolinska University Hospital (n=159) and Erasmus Medical Center (n=344). RSI was applied as previously described. Results We tested RSI in RT-treated patients (Karolinska). Patients predicted to be radiosensitive (RS) had an improved 5 yr relapse-free survival when compared with radioresistant (RR) patients (95% vs. 75%, p=0.0212) but there was no difference between RS/RR patients treated without RT (71% vs. 77%, p=0.6744), consistent with RSI being RT-specific (interaction term RSIxRT, p=0.05). Similarly, in the Erasmus dataset RT-treated RS patients had an improved 5-year distant-metastasis-free survival over RR patients (77% vs. 64%, p=0.0409) but no difference was observed in patients treated without RT (RS vs. RR, 80% vs. 81%, p=0.9425). Multivariable analysis showed RSI is the strongest variable in RT-treated patients (Karolinska, HR=5.53, p=0.0987, Erasmus, HR=1.64, p=0.0758) and in backward selection (removal alpha of 0.10) RSI was the only variable remaining in the final model. Finally, RSI is an independent predictor of outcome in RT-treated ER+ patients (Erasmus, multivariable analysis, HR=2.64, p=0.0085). Conclusions RSI is validated in two independent breast cancer datasets totaling 503 patients. Including prior data, RSI is validated in five independent cohorts (621 patients) and represents, to our knowledge, the most extensively validated molecular signature in radiation oncology. PMID:22832933

  18. Fibroblast radiosensitivity versus acute and late normal skin responses in patients treated for breast cancer

    International Nuclear Information System (INIS)

    Brock, William A.; Tucker, Susan L.; Geara, Fady B.; Wike, Jennifer; Peters, Lester J.; Turesson, Ingela; Nyman, Jan

    1995-01-01

    Purpose/Objective: To determine if the radiosensitivity of normal human skin fibroblasts, measured in early passage cultures, is significantly correlated with the degree of acute or late normal skin damage in patients treated for breast cancer with radiotherapy. Methods and Materials: In the 1970s, a series of breast cancer patients was treated at the Department of Oncology in Gothenburg, Sweden with postoperative irradiation to the parasternal region. Patients were treated bilaterally using different fractionation schedules and doses to the right and left fields. Peak acute reactions were scored on a six-point scale, and skin erythema was measured by reflectance spectrophotometry. Telangiectasia was graded over time on a six-point scale. In April 1992, two small skin biopsies were obtained from 22 patients in two treatment groups (i.e., four dose-fractionation schedules) and, using either delayed or immediate plating, fibroblast radiosensitivity was measured in early passage cultures by clonogenic survival, after high and low dose-rate irradiations. Survival at 2.0 Gy (SF2) was calculated from complete survival curves. Results: To test assay reproducibility, SF2 values derived from paired biopsies of the same patient (12 cases) were compared. A reasonably good correlation (p = 0.075) was obtained for SF2s determined by high dose-rate irradiations with immediate plating, but not for delayed plating or low dose-rate treatments. The median coefficient of variation in the replicate SF2s after high dose-rate treatment and immediate plating was 13%, suggesting that the poor correlation in paired SF2 values is due to the magnitude of the uncertainty in SF2 relative to the overall spread in SF2 values between patients (CV = 28%). Individual SF2 values and averaged values from patients with data from two biopsies were compared with the acute and late clinical reactions. A significant negative correlation was found between SF2 and relative clinical response, but only when

  19. Relationship between in vitro chromosomal radiosensitivity of peripheral blood lymphocytes and the expression of normal tissue damage following radiotherapy for breast cancer

    International Nuclear Information System (INIS)

    Barber, J.B.P.; Burrill, W.; Spreadborough, A.R.; Levine, E.; Warren, C.; Scott, D.; Kiltie, A.E.; Roberts, S.A.

    2000-01-01

    There is a need for rapid and reliable tests for the prediction of normal tissue responses to radiotherapy, as this could lead to individualization of patient radiotherapy schedules and thus improvements in the therapeutic ratio. Because the use of cultured fibroblasts is too slow to be practicable in a clinical setting, we evaluated the predictive role of assays of lymphocyte chromosomal radiosensitivity in patients having radiotherapy for breast cancer. Radiosensitivity was assessed using a macronucleus (MN) assay at high dose rate (HDR) and low dose rate (LDR) on lymphocytes irradiated in the G 0 phase of the cell cycle (Scott D, Barber JB, Levine EL, Burril W, Roberts SA. Radiation-induced micronucleus induction in lymphocytes identifies a frequency of radiosensitive cases among breast cancer patients: a test for predisposition? Br. J. Cancer 1998;77;614-620) and an assay of G 2 phase chromatid radiosensitivity ('G 2 assay') (Scott D, Spreadborough A, Levine E, Roberts SA. Genetic predisposition in breast cancer. Lancet 1994; 344: 1444). In a study of acute reactions, blood samples were taken from breast cancer patients before the start of radiotherapy, and the skin reaction documented. 116 patients were tested with the HDR MN assay, 73 with the LDR MN assay and 123 with the G 2 assay. In a study of late reactions, samples were taken from a series of breast cancer patients 8-14 years after radiotherapy and the patients assessed for the severity of late effects according to the 'LENT SOMA' scales. 47 were tested with the HDR assay, 26 with the LDR assay and 19 with the G 2 assay. For each clinical endpoint, patients were classified as being normal reactors or 'highly radiosensitive patients' (HR patients (Burnet NG. Johansen J, Turesson I, Nyman J. Describing patients' normal tissue reactions: Concerning the possibility of individualising radiotherapy dose prescriptions based on potential predictive assays of normal tissue radiosensitivity. Int. J. Cancer 1998

  20. Assessment of individual radiosensitivity in human lymphocytes of cancer patients and its correlation with adverse side effects to radiation therapy

    CERN Document Server

    Di Giorgio, M; Busto, E; Mairal, L; Menendez, P; Roth, B; Sardi, M; Taja, M R; Vallerga, M B

    2003-01-01

    Background and purpose: Individual radiosensitivity is an inherent characteristic, associated with an increased reaction to ionizing radiation on the human body. Biological endpoints such as clonogenic survival, chromosome aberration formation and repair capacity of radiation-induced damage have been applied to evaluate individual radiosensitivity in vitro. 5%-7% of cancer patients develop adverse side effects to radiation therapy in normal tissues within the treatment field, which are referred as 'clinical radiation reactions' and include acute effects, late effects and cancer induction. It has been hypothesized that the occurrence and severity of these reactions are mainly influenced by genetic susceptibility to radiation. Additionally, the nature of the genetic disorders associated with hypersensitivity to radiotherapy suggests that DNA repair mechanisms are involved. Consequently, the characterization of DNA repair in lymphocytes through cytokinesis blocked micronucleus (MN) and alkaline single-cell micro...

  1. Effect of quercetin on radiosensitivity of human uterine cervix cancer HeLa cells

    International Nuclear Information System (INIS)

    Liang Xiaofang; Hong Chengjiao; Zhang Baoguo

    2009-01-01

    In order to investigate the effects of Quercetin on radiosensitivity of human Uterine Cervix Cancer HeLa cells, MTT assay and clonogenic assay were performed to evaluate the cytotoxicity of Quercetin on the cells. Clonogenic assay was used to observe its effects on the radiosensitivity of the cells. MTT result shows that the inhibition of Quercetin on the cells is in the dose-dependent and time-dependent. And the clonogenic assay result shows that the effect of Quercetin on HeLa cells can be divided into two parts, one for the inhibition of HeLa cells and another for the induction of HeLa cell death. The other clonogenic assay result also shows Quercetin can decrease clonogenic survival rate of HeLa cells exposed to X rays. The study shows Quercetin might enhance the radiosensitivity of the HeLa cell line. And it may provide a useful evaluation to combination of ionizing radiation and Quercetin for cancer patients. (authors)

  2. Metformin kills and radiosensitizes cancer cells and preferentially kills cancer stem cells

    Science.gov (United States)

    Song, Chang W.; Lee, Hyemi; Dings, Ruud P. M.; Williams, Brent; Powers, John; Santos, Troy Dos; Choi, Bo-Hwa; Park, Heon Joo

    2012-01-01

    The anti-cancer effects of metformin, the most widely used drug for type 2 diabetes, alone or in combination with ionizing radiation were studied with MCF-7 human breast cancer cells and FSaII mouse fibrosarcoma cells. Clinically achievable concentrations of metformin caused significant clonogenic death in cancer cells. Importantly, metformin was preferentially cytotoxic to cancer stem cells relative to non-cancer stem cells. Metformin increased the radiosensitivity of cancer cells in vitro, and significantly enhanced the radiation-induced growth delay of FSaII tumors (s.c.) in the legs of C3H mice. Both metformin and ionizing radiation activated AMPK leading to inactivation of mTOR and suppression of its downstream effectors such as S6K1 and 4EBP1, a crucial signaling pathway for proliferation and survival of cancer cells, in vitro as well as in the in vivo tumors. Conclusion: Metformin kills and radiosensitizes cancer cells and eradicates radioresistant cancer stem cells by activating AMPK and suppressing mTOR. PMID:22500211

  3. Predisposition to cancer and radiosensitivity

    International Nuclear Information System (INIS)

    Pichierri, P.; Franchitto, A.; Palitti, F.

    2000-01-01

    Many cancer-prone diseases have been shown to be radiosensitive. The radiosensitivity has been attributed to pitfalls in the mechanisms of repair of induced DNA lesions or to an impaired cell cycle checkpoint response. Although discrepancies exist in the results obtained by various authors on the radiosensitivity of individuals affected by the same disease, these can be attributed to the large variability observed already in the response to radiation of normal individuals. To date three test are commonly used to assess radiosensitivity in human cells: survival, micronucleus and G 2 chromosomal assay. The three tests may be performed using either fibroblasts or peripheral blood lymphocytes and all the three tests share large interindividual variability. In this regard a new approach to the G 2 chromosomal assay which takes into account the eventual differences in cell cycle progression among individuals has been developed. This new approach is based on the analysis of G 2 homogeneous cell populations. Cells irradiated are immediately challenged with medium containing bromodeoxyuridine (BrdU rd). Then cells are sampled at different post-irradiation times and BrdU rd incorporation detected on metaphases spread and the scoring is done only at time points showing similar incidence of labelled cells among the different donors. Using this approach it has been possible to reduce the interindividual variability of the G 2 chromosomal assay. (author)

  4. Correlation between residual level of DNA double-strand breaks and the radiosensitivity of cancer cells

    International Nuclear Information System (INIS)

    Sun Jianxiang; Sun Weijian; Sui Jianli; Zhou Pingkun

    2008-01-01

    Objective: To understand the variation of the DNA double-strand break rejoining capacity among different cultured cancer cell lines and the primary cancer cells from brain cancer patients, and to explore the predictor of radiotherapy responses of cancers. Methods: DNA double-strand breaks (DSBs) were induced by 60 Co γ-irradiation. Pulsed-field gel electrophoresis was used to analyze the initial production and rejoining of DNA DSBs. Radiosensitivity was determined by in vitro assay of clonogenic-forming capacity. Results: A wide variation of radiosensitivity, e.g. the survival parameter of Do varied from 0.65 to 2.15 Gy, was displayed among the eight cell lines derived from different type of cancers. Although differential level of initial DNA DSBs induced by 20 Gy γ-rays was observed among various cell lines, it was not correlated with the radiosensitivity. The deficiency of DNA DSB rejoining in radiosensitive cell lines was shown either in the early rapid-rejoining phase (SX-10 cells) or in the late slow-rejoining phase (A2780 cells). A significant relationship was observed between the residual level of DNA DSBs measured at 2 h post-20 Gy irradiation and the cellular radiosensitivity (D 0 or SF 2 ). The kinetic curves of rejoining DNA DSBs in the primary human brain tumor cells indicated a variation on DSB rejoining capacity among different individual tumor. The residual level of DNA DSBs after 2 h of rejoining post 20 Gy irradiation in primary human brain tumor cells is compatible to the results obtained in vitro culture cancer cell lines. Conclusions: The residual level of DNA DSBs is correlated with radioresistance of cancer cells, and the residual DNA damage is a useful parameter in predicting the response of tumor tissue to radiotherapy. (authors)

  5. Uroporphyrinogen decarboxylase is a radiosensitizing target for head and neck cancer.

    Science.gov (United States)

    Ito, Emma; Yue, Shijun; Moriyama, Eduardo H; Hui, Angela B; Kim, Inki; Shi, Wei; Alajez, Nehad M; Bhogal, Nirmal; Li, Guohua; Datti, Alessandro; Schimmer, Aaron D; Wilson, Brian C; Liu, Peter P; Durocher, Daniel; Neel, Benjamin G; O'Sullivan, Brian; Cummings, Bernard; Bristow, Rob; Wrana, Jeff; Liu, Fei-Fei

    2011-01-26

    Head and neck cancer (HNC) is the eighth most common malignancy worldwide, comprising a diverse group of cancers affecting the head and neck region. Despite advances in therapeutic options over the last few decades, treatment toxicities and overall clinical outcomes have remained disappointing, thereby underscoring a need to develop novel therapeutic approaches in HNC treatment. Uroporphyrinogen decarboxylase (UROD), a key regulator of heme biosynthesis, was identified from an RNA interference-based high-throughput screen as a tumor-selective radiosensitizing target for HNC. UROD knockdown plus radiation induced caspase-mediated apoptosis and cell cycle arrest in HNC cells in vitro and suppressed the in vivo tumor-forming capacity of HNC cells, as well as delayed the growth of established tumor xenografts in mice. This radiosensitization appeared to be mediated by alterations in iron homeostasis and increased production of reactive oxygen species, resulting in enhanced tumor oxidative stress. Moreover, UROD was significantly overexpressed in HNC patient biopsies. Lower preradiation UROD mRNA expression correlated with improved disease-free survival, suggesting that UROD could potentially be used to predict radiation response. UROD down-regulation also radiosensitized several different models of human cancer, as well as sensitized tumors to chemotherapeutic agents, including 5-fluorouracil, cisplatin, and paclitaxel. Thus, our study has revealed UROD as a potent tumor-selective sensitizer for both radiation and chemotherapy, with potential relevance to many human malignancies.

  6. Hereditary syndromes with enhanced radiosensitivity

    International Nuclear Information System (INIS)

    Lohmann, D.

    2000-01-01

    Sensitivity to ionizing radiation is modified by heritable genetic factors. This is exemplified by heritable disorders that are characterized by predisposition to the development of neoplasms. Cells derived from patients with ataxia telangiectasia, Nijmegen breakage syndrome and ataxia telangiektasia-like disorder show a markedly changed reaction to exposure to ionizing radiation. Correspondingly, at least in patients with ataxia telangiectasia, an enhanced radiosensitivity that is of clinical importance has been observed. In addition to these recessive disorders, some autosomal dominant cancer predisposition syndromes are associated with increased radiosensitivity. As cells from these patients still have a normal allele (that is dominant over the mutant allele), the cellular phenotype is most often normal. Specifically, there is no overtly altered reaction in response to ionizing radiation. Nevertheless, two dominant cancer predisposition syndromes, namely hereditary retinoblastoma and naevoid basal cell carcinoma syndrome, are associated with a enhanced radiosensitivity as indicated by increased development of tumors following radiation therapy. (orig.) [de

  7. Phytochemicals radiosensitize cancer cells by inhibiting DNA repair

    International Nuclear Information System (INIS)

    Singh, Rana P.

    2017-01-01

    Solid tumors are mostly treated with radiotherapy. Radiotherapy is toxic to normal tissues and also promote the invasiveness and radioresistance in cancer cells. The resistance against radiotherapy and adverse effects to normal cells reduce the overall therapeutic effects of the treatment. Radiosensitizing agents usually show limited success during clinical trials. Therefore, the search and development of new radiosensitizers showing selective response to only cancer cells is desirable. We analyzed the radiosensitizing effects including cell death effect of silibinin, a phytochemical on prostate cancer cells. Silibinin enhanced gamma radiation (2.5-10 Gy) induced inhibition in colony formation selectively in prostate cancer cells. In cell cycle progression, G2/M phase is the most sensitive phase for radiation-induced damage which was delayed by the compound treatment in radiation exposed cells. The lower concentrations of silibinin substantially enhanced radiation-induced apoptosis. A prolonged reactive oxygen species production was also observed in these treatments EGFR signaling pathway can contribute to radiation-induced pro-survival mechanisms and to the therapeutic resistance. Agent treatment reduced the IR-induced EGFR phosphorylation and consequently reversed the resistance mediating mechanisms within the cancer cell. Thus, inhibiting DNA repair in cancer cells would enhance therapeutic response of radiation in cancer cells. Silibinin affected the localization of EGFR and DNA-dependent protein kinase, the DNA-PK is known to be an important mediator of DSB repair in human cells, and showed increased number of pH2AX (ser139) foci, and thus indicating lower DNA repair in these cancer cells. This was also confirmed in the tumor xenograft study. Our findings suggest that a combination of silibinin with radiation could be an effective treatment of radioresistant human prostate cancer and warrants further investigation. (author)

  8. Analysis of the individual radio sensitivity of breast cancer patients; Untersuchungen zur individuellen Strahlenempfindlichkeit von Brustkrebspatientinnen

    Energy Technology Data Exchange (ETDEWEB)

    Auer, Judith

    2013-04-04

    Individual radiosensitivity has a crucial impact on radiotherapy related side effects. A prediction of individual radiosensitivity could avoid these side effects. Our aim was to study a breast cancer collective for its variation of individual radiosensitivity. Peripheral blood samples were obtained from 129 individuals. 67 breast cancer patients and 62 healthy and age matched individuals were looked at and their individual radiosensitivity was estimated by a 3-color Fluorescence in situ hybridization approach. Blood samples were obtained (i) before starting adjuvant radiotherapy and were in vitro irradiated by 2 Gy; (ii) after 5 single doses of 1.8 Gy and after 72 h had elapsed. DNA of lymphocytes was probed with whole chromosome painting for chromosomes 1, 2 and 4. The rate of breaks per metaphase was analyzed and used as a predictor of individual radiosensitivity. Breast cancer patients were distinctly more radio-sensitive compared to healthy controls. Additionally the distribution of the cancer patients' radiosensitivity was broader. A subgroup of 9 rather radio-sensitive and 9 rather radio-resistant patients was identified. A subgroup of patients aged between 40 and 50 was distinctly more radio-sensitive than younger or older patients. The in vivo irradiation approach was not applicable to detect individual radiosensitivity. In the breast cancer collective a distinctly resistant and sensitive subgroup is identified, which could be subject for treatment adjustment. Especially in the range of age 40 to 50 patients have an increased radiosensitivity. An in vivo irradiation in a breast cancer collective is not suitable to estimate individual radiosensitivity due to a low deposed dose.

  9. Radiosensitization effect of CMNa on hypoxic pancreatic cancer cell in vitro

    International Nuclear Information System (INIS)

    Yin Lijie; Zhang Li; Ding Tiangui; Peng Zhaoxiang; Yu Huan; Gao Yuwei

    2006-01-01

    Objective: To investigate the effects of glycodidazolum natrium (CMNa) on pancreatic cancer cells under hypoxic condition. Methods: The human pancreatic cancer Panc-1 cells were exposed to a single fraction of high-dose γ-ray radiation either with CMNa or under hypoxic condition. The percentage of dead cells was detected with a multiwell plated reader, and fluorescence intensities of propidium iodide were measured before and after digitonin treatment. The sensitizing effect of CMNa on cell killing induced by high-dose irradiation was evaluated by time and concentration dependence. The selective radiosensitive effect of CMNa on hypoxia was evaluated by flow cytometry. Results: The death rate of pancreatic cancer Panc-1 cells paralleled with the increasing concentration of CMNa under hypoxic condition after 30 gray irradiation. The selective radiosensitive effect of CMNa on hypoxia was time-dependent. Conclusions: CMNa can enhance the radiosensitivity of pancreatic cancer Pane-1 cells under hypoxic condition with high-dose irradiation. (authors)

  10. Radiosensitivity of skin fibroblasts from atomic bomb survivors with and without breast cancer

    International Nuclear Information System (INIS)

    Ban, Sadayuki; Setlow, R.B.; Bender, M.A.

    1990-11-01

    Fibroblasts were established in vitro from skin biopsies obtained from 55 women and one man with or without breast cancer and with or without exposure to radiation from the atomic bomb explosion in Hiroshima. The radiosensitivity of these cells was evaluated by clonogenic assays after exposure to X rays or to fission neutrons from a 252 Cf source. Data were fitted to a multitarget model, S/S 0 = A[1-(1-e kD ) N ], for both X-ray and neutron dose-survival curves. A single-hit model, S/S 0 = Ae kD , fits the neutron dose-survival responses as well. These was no difference in the means or variances of radiosensitivity between exposed and nonexposed groups, or between patients with or without breast cancer. Hence, although the sample is not large, it provides no support for the hypothesis that A-bomb radiation preferentially induces breast cancer in women whose cells in vitro are sensitive to cell killing by radiation. (author)

  11. Individual radiosensitivity measured with lymphocytes may be used to predict the risk of fibrosis after radiotherapy for breast cancer

    International Nuclear Information System (INIS)

    Hoeller, Ulrike; Borgmann, Kerstin; Bonacker, Michael; Kuhlmey, Antje; Bajrovic, Amira; Jung, Horst; Alberti, Winfried; Dikomey, Ekkehard

    2003-01-01

    Background and purpose: To analyse the relationship of individual cellular radiosensitivity and fibrosis after breast conserving therapy. A new model was used describing the percentage of patients developing fibrosis per year and per patient at risk. Patients and methods: In a retrospective study, 86 patients were included, who had undergone breast conserving surgery and irradiation of the breast with a median dose of 55 Gy (54-55 Gy) given at 2.5 Gy/fraction (n=57) or 2 Gy/fraction (n=29). Median age was 62 years (range 44-86) and median follow-up was 7.5 years (range 5-17). Patients were examined for fibrosis according to the LENT/SOMA score. For analysis, fibrosis was classified as grade 0 and grade 1 (G0-1) or present grade 2 and grade 3 (G2-3). The time to complete development of fibrosis was determined by analysis of yearly mammograms. Individual cellular radiosensitivity was determined by scoring lethal chromosomal aberrations in in vitro irradiated (6 Gy) lymphocytes using metaphase technique. Patients with low/intermediate cellular radiosensitivity were compared with patients with high cellular radiosensitivity using actuarial methods. Results: Ten patients developed fibrosis at 1-8 years after radiotherapy. Individual cellular radiosensitivity was described by normal distribution of lethal chromosomal aberrations, the average was 5.47 lethal aberrations per cell (standard deviation (SD) 0.71). Cellular radiosensitivity was defined as low/intermediate (≤6.18 lethal aberrations) in 73 patients and high (>6.18 lethal aberrations; mean+SD) in 13 patients. In both groups, the actuarial rate of fibrosis-free patients decreased exponentially with time after radiotherapy. Patients with high cellular radiosensitivity showed a 2.3-fold higher annual rate for fibrosis than patients with intermediate and low radiosensitivity (3.6 versus 1.6% per year). Conclusions: In breast cancer patients, high individual cellular radiosensitivity as determined by the number of

  12. Radiogenomics: predicting clinical normal tissue radiosensitivity

    DEFF Research Database (Denmark)

    Alsner, Jan

    2006-01-01

    Studies on the genetic basis of normal tissue radiosensitivity, or  'radiogenomics', aims at predicting clinical radiosensitivity and optimize treatment from individual genetic profiles. Several studies have now reported links between variations in certain genes related to the biological response...... to radiation injury and risk of normal tissue morbidity in cancer patients treated with radiotherapy. However, after these initial association studies including few genes, we are still far from being able to predict clinical radiosensitivity on an individual level. Recent data from our own studies on risk...

  13. Radiosensitivity is increased by knockdown of FTS in uterine cervical cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Park, Wo Yoon; Anandharaj, Arunkumar; Cinghu, Senthikumar; Kim, Won Dong [Dept. of Radiation Oncology, Chungbuk National University College of Medicine, Cheongju (Korea, Republic of); Yu, Jae Ran [Dept. of Environmental and Tropical Medicine, Konkuk University College of Medicine, Seoul (Korea, Republic of)

    2012-04-15

    Uterine cervical cancer is still the second largest cancer in women worldwide, despite of effective screening methods. Radiotherapy is used to treat all the stages of cervical cancer and more than 60% of cervical cancer patients receive radiotherapy. New therapeutic targets or approaches are needed to further increase the results of radiotherapy. In the present study, we demonstrated the radiation induced overexpression and nuclear export of FTS in cervical cancer cells. Furthermore, we showed that silencing of FTS expression with FTS shRNA enhanced radiosensitivity of cervical cancer cells, induced cell cycle arrest and apoptosis FTS is involved in radioresistance of cervical cancer. Targeted inhibition of FTS can shutdown the key elemental characteristics of cervical cancer and could lead to an effective therapeutic strategy.

  14. Radiosensitivity is increased by knockdown of FTS in uterine cervical cancer cells

    International Nuclear Information System (INIS)

    Park, Wo Yoon; Anandharaj, Arunkumar; Cinghu, Senthikumar; Kim, Won Dong; Yu, Jae Ran

    2012-01-01

    Uterine cervical cancer is still the second largest cancer in women worldwide, despite of effective screening methods. Radiotherapy is used to treat all the stages of cervical cancer and more than 60% of cervical cancer patients receive radiotherapy. New therapeutic targets or approaches are needed to further increase the results of radiotherapy. In the present study, we demonstrated the radiation induced overexpression and nuclear export of FTS in cervical cancer cells. Furthermore, we showed that silencing of FTS expression with FTS shRNA enhanced radiosensitivity of cervical cancer cells, induced cell cycle arrest and apoptosis FTS is involved in radioresistance of cervical cancer. Targeted inhibition of FTS can shutdown the key elemental characteristics of cervical cancer and could lead to an effective therapeutic strategy

  15. Radiosensitization by PARP inhibition to proton beam irradiation in cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Hirai, Takahisa [Department of Radiation Oncology, Juntendo University Faculty of Medicine, Bunkyo-ku, Tokyo (Japan); Division of Chemotherapy and Clinical Cancer Research, National Cancer Center Research Institute, Chuo-ku, Tokyo (Japan); Saito, Soichiro; Fujimori, Hiroaki [Division of Chemotherapy and Clinical Cancer Research, National Cancer Center Research Institute, Chuo-ku, Tokyo (Japan); Matsushita, Keiichiro; Nishio, Teiji [Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima-shi, Hiroshima (Japan); Okayasu, Ryuichi [International Open Laboratory, National Institute of Radiological Science, Chiba-shi, Chiba (Japan); Masutani, Mitsuko, E-mail: mmasutan@nagasaki-u.ac.jp [Division of Chemotherapy and Clinical Cancer Research, National Cancer Center Research Institute, Chuo-ku, Tokyo (Japan); Department of Frontier Life Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki (Japan)

    2016-09-09

    The poly(ADP-ribose) polymerase (PARP)-1 regulates DNA damage responses and promotes base excision repair. PARP inhibitors have been shown to enhance the cytotoxicity of ionizing radiation in various cancer cells and animal models. We have demonstrated that the PARP inhibitor (PARPi) AZD2281 is also an effective radiosensitizer for carbon-ion radiation; thus, we speculated that the PARPi could be applied to a wide therapeutic range of linear energy transfer (LET) radiation as a radiosensitizer. Institutes for biological experiments using proton beam are limited worldwide. This study was performed as a cooperative research at heavy ion medical accelerator in Chiba (HIMAC) in National Institute of Radiological Sciences. HIMAC can generate various ion beams; this enabled us to compare the radiosensitization effect of the PARPi on cells subjected to proton and carbon-ion beams from the same beam line. After physical optimization of proton beam irradiation, the radiosensitization effect of the PARPi was assessed in the human lung cancer cell line, A549, and the pancreatic cancer cell line, MIA PaCa-2. The effect of the PARPi, AZD2281, on radiosensitization to Bragg peak was more significant than that to entrance region. The PARPi increased the number of phosphorylated H2AX (γ-H2AX) foci and enhanced G2/M arrest after proton beam irradiation. This result supports our hypothesis that a PARPi could be applied to a wide therapeutic range of LET radiation by blocking the DNA repair response. - Highlights: • Effective radiosensitizers for particle radiation therapy have not been reported. • PARP inhibitor treatment radiosensitized after proton beam irradiation. • The sensitization at Bragg peak was greater than that at entrance region. • DSB induction and G2/M arrest is involved in the sensitization mechanism.

  16. Fibroblast radiosensitivity versus acute and late normal skin responses in patients treated for breast cancer

    International Nuclear Information System (INIS)

    Brock, W.A.; Wike, J.; Tucker, S.L.

    1995-01-01

    To determine if the radiosensitivity of normal human skin fibroblasts, measured in early passage cultures, is significantly correlated with the degree of acute or late normal skin damage in patients treated for breast cancer with radiotherapy. To test assay reproducibility, SF2 values derived from paired biopsies of the same patient (12 cases) were compared. A reasonably good correlation (p = 0.075) was obtained for SF2s determined by high dose-rate irradiations with immediated plating, but not for delayed plating or low dose-rate treatments. The median coefficient of variation in the replicate SF2s after high dose-rate treatment and immediate plating was 13%, suggesting that the poor correlation in paired SF2 values is due to the magnitude of the uncertainty in SF2 relative to the overall spread in SF2 values between patients (CV = 28%). Individual SF2 values and averaged values from patients with data from two biopsies were compared with the acute and late clinical reactions. A significant negative correlation was found between SF2 and relative clinical response, but only when averaged high dose-rate SF2 values and telangiectasia scores were compared. There was no significant correlation between average SF2 values and acute responses or between individual SF2 measurements and either the acute or late clinical response. The results of this study suggest that the degree of late telangiectasia is at least partially dependent upon the intrinsic cellular radiosensitivity of normal fibroblasts, but the relationship is not clear cut. Multiple replicate assays are necessary to obtain reliable estimates of fibroblast SF2 values using current techniques. 20 refs., 3 figs., 3 tabs

  17. MiR-122 Induces Radiosensitization in Non-Small Cell Lung Cancer Cell Line

    Directory of Open Access Journals (Sweden)

    Debin Ma

    2015-09-01

    Full Text Available MiR-122 is a novel tumor suppresser and its expression induces cell cycle arrest, or apoptosis, and inhibits cell proliferation in multiple cancer cells, including non-small cell lung cancer (NSCLC cells. Radioresistance of cancer cell leads to the major drawback of radiotherapy for NSCLC and the induction of radiosensitization could be a useful strategy to fix this problem. The present work investigates the function of miR-122 in inducing radiosensitization in A549 cell, a type of NSCLC cells. MiR-122 induces the radiosensitization of A549 cells. MiR-122 also boosts the inhibitory activity of ionizing radiation (IR on cancer cell anchor-independent growth and invasion. Moreover, miR-122 reduced the expression of its targeted genes related to tumor-survival or cellular stress response. These results indicate that miR-122 would be a novel strategy for NSCLC radiation-therapy.

  18. Chromosomal fragility syndrome and family history of radiosensitivity as indicators for radiotherapy dose modification

    International Nuclear Information System (INIS)

    Alsbeih, Ghazi; Story, Michael D.; Maor, Moshe H.; Geara, Fady B.; Brock, William A.

    2003-01-01

    Beside a few known radiosensitive syndromes, a patient's reaction to radiotherapy is difficult to predict. In this report we describe the management of a pediatric cancer patient presented with a family history of radiosensitivity and cancer proneness. Laboratory investigations revealed a chromosomal fragility syndrome and an increased cellular radiosensitivity in vitro. AT gene sequencing revealed no mutations. The patient was treated with reduced radiation doses to avoid the presumed increased risks of toxicity to normal tissues. The patient tolerated well the treatment with no significant acute or late radiation sequelae. Five years later, the patient remains both disease and complications free. While an accurate laboratory test for radiosensitivity is still lacking, assessments of chromosomal fragility, cell survival and clinical medicine will continue to be useful for a small number of patients

  19. Electron microscopic study on radiosensitivity of uterine cervical cancer

    Energy Technology Data Exchange (ETDEWEB)

    Iwai, S; Shiozawa, K; Tsukamoto, T; Noguchi, H; Tsukahara, Y [Shinshu Univ., Matsumoto, Nagano (Japan). Faculty of Medicine

    1974-11-01

    The effects of 1000 R of tele-cobalt upon the changes in the primary lesions of uterine cervical cancer with time were studied with an electron microscope. In addition, twenty cases which were proven to have cancer tissues (10 cases of IInd stage of cancer, 8 cases of IIIrd stage of cancer and 2 cases of IVth stage of cancer) were studied. Four cases were favourably sensitive, 7 cases moderately sensitive and 9 cases unfavourably sensitive to radiation. In favourably radio-sensitive cases, the changes in the cancer cells first appeared in the nucleus. There were other changes such as local clumping of chromatin and, specifically, vacuolization of the nucleus. The changes in the endoplasmic reticulum appeared somewhat late. In addition, the disturbance of mitochondria and the decrease or disappearance of ribosomes were specifically due to radiation injury. From the point of view of changes with time, Golgi's apparatus was enlarged and the membrane of the endoplasmic reticulum was degenerated at the 1st day. At the 3rd day, vacuolization of the nucleus appeared, the nuclear corpuscles were increased, the nucleoplasm became thin, and mitochondria was enlarged and degenerated. At the 5th day, the nuclear membrane disappeared, the nucleus was destroyed, large vacuolization of the endoplasmic reticulum was seen, free ribosomes were decreased, and changes around the endoplasmic reticulum were observed. At the 7th day, collagen around the endoplasmic reticulum appeared. In favourably radiosensitive cases, individual tumor cells showed the same degeneration, which fairly corresponded to that evaluated by the histological observation. The disturbance of the cells was caused by radiation, so-called ''burning'' of the cells. Radiation protection of the cells against burning was considered in terms of their radiosensitivity.

  20. Chromosomal radiosensitivity during the G2 cell-cycle period of skin fibroblasts from individuals with familial cancer

    International Nuclear Information System (INIS)

    Parshad, R.; Sanford, K.K.; Jones, G.M.

    1985-01-01

    The authors reported previously that human cells after neoplastic transformation in culture had acquired an increased susceptibility to chromatid damage induced by x-irradiation during the G2 phase of the cell cycle. Evidence suggested that this results from deficient DNA repair during G2 phase. Cells derived from human tumors also showed enhanced G2-phase chromosomal radiosensitivity. Furthermore, skin fibroblasts from individuals with genetic diseases predisposing to a high risk of cancer, including ataxia-telangiectasia, Bloom syndrome, Fanconi anemia, and xeroderma pigmentosum exhibited enhanced G2-phase chromosomal radiosensitivity. The present study shows that apparently normal skin fibroblasts from individuals with familial cancer--i.e., from families with a history of neoplastic disease--also exhibit enhanced G2-phase chromosomal radiosensitivity. This radiosensitivity appears, therefore, to be associated with both a genetic predisposition to cancer and a malignant neoplastic state. Furthermore, enhanced G2-phase chromosomal radiosensitivity may provide the basis for an assay to detect genetic susceptibility to cancer

  1. The docetaxel radiosensitization experience for the treatment of unresectable esophageal cancer

    International Nuclear Information System (INIS)

    Maruyama, Shoji; Maruyama, Michio; Tanami, Hideaki

    2005-01-01

    Docetaxel is an increasingly important drug for the treatment of esophageal cancer. The docetaxel radiosensitization has been established in cancer cell lines. The therapeutic response and toxicity of a weekly docetaxel in combination with radiotherapy for unresectable esophageal cancer were examined. Ten patients with locally advanced or metastatic squamous cell esophageal cancer were recruited in the following protocol. The median age was 65.7 years. Patients received radiation in 2 Gy single daily fractions to a total dose of 60 Gy. Docetaxel (10 mg/m 2 ) was administered weekly for 6 consecutive weeks. One patient could not be evaluated. The overall response rate was 77% with 11% complete response (CR) and 66% partial response (PR). Mild grade 2 leukocytes toxicity was observed in 2/10 patients, which enforced the treatment absence for 7-14 days. Grade 2 stomatitis was noted in one patient. No severe grade 3 adverse effects were observed. It is concluded that low-dose docetaxel with radiotherapy is feasible and, a high response rate can be expected. Toxicity is modest, and this protocol may be useful for the outpatients or neoadjuvant chemotherapy. (author)

  2. Cabazitaxel-induced stabilization of microtubules enhances radiosensitivity in ovarian cancer cells

    Directory of Open Access Journals (Sweden)

    Charles eKunos

    2013-09-01

    Full Text Available Background: Up to 40% of women with ovarian cancer have short disease-free intervals due to molecular mechanisms of chemotherapy resistance. New therapeutic strategies are sought. Ovarian cancers are sensitive to radiochemotherapy. The taxane cabazitaxel (XRP6258, Jevtana promotes tubulin assembly and stabilizes microtubules against depolymerization in cells, acting similarly in mechanism to paclitaxel. Here, sequences of cabazitaxel-radiation co-administration are tested for drug-alone cytotoxicity and optimal radiosensitization.Methods: SKOV3, OVCAR3, and TOV-112D ovarian cancer cells were administered cabazitaxel 24 h before (first, 18 h before (second, together (third, or 24 h after (fourth a single radiation dose, and then, investigated by clonogenic assay and flow cytometric assays. Radiation dose-cell survival data were fitted by two-stage multivariate analyses of variance. High content flow cytometry partitioned cabazitaxel effects into G2-phase versus M-phase events by DNA content, cyclin A2, and phospho-S10-histone H3 (PHH3. Paclitaxel served as a comparator. Findings: Cabazitaxel cytotoxicity and radiosensitization were dose dependent. Cabazitaxel added 24 h before radiation was the most lethal schedule. DNA content measurements by flow cytometry showed that cabazitaxel-treated cells accumulated in the radiosensitive G2/M 4C DNA complement compartment. Cytometry also showed that surviving cabazitaxel-induced cell cycle arrested cells resolve the arrest by entering 4C or by 8C DNA complement cell cycles.Interpretation: The radiosensitizing effect of cabazitaxel was schedule dependent, due to cell cycle redistribution, and best when cabazitaxel was given 24 h before radiation. Clinical trials of administering both cabazitaxel and radiation should be explored in women with chemoresistant ovarian cancer. Funding: Case Comprehensive Cancer Center and Sanofi-Aventis

  3. The radiosensitizing effect of doranidazole on human colorectal cancer cells exposed to high doses of irradiation

    International Nuclear Information System (INIS)

    Zhang, Li; Gong, Aimin; Ji, Jun; Wu, Yuanyuan; Zhu, Xiaoyu; Lv, Suqing; Lv, Hongzhu; Sun, Xizhuo

    2007-01-01

    This paper investigates the effects of a new radiosensitizer, doranidazole, and enhancing irradiation on colorectal cancer cells. The radiosensitizing effect of doranidazole was determined using colony formation and propidium iodide (PI) assays to measure cell growth inhibition and the cell killing effect of human colorectal cancer cell lines exposed to high doses of γ-ray irradiation under hypoxic conditions in vitro. Fluorescence staining and cell migration assays were also used to assess the radiosensitizing effect. Cell proliferation evaluated by clonogenic survival curves was significantly inhibited by 5 mmol/L doranidazole, particularly at doses ranging from 10 to 30 Gy of irradiation. The radiosensitizing effect of doranidazole on colorectal cancer cells occurs in a time- and dose-dependent manner. Doranidazole also inhibited the mobility of cell invasion and migration. Doranidazole can enhance the killing effect and the cell growth inhibition of colorectal cancer after high-dose irradiation in a time and dose-dependent manner

  4. Enterolactone: A novel radiosensitizer for human breast cancer cell lines through impaired DNA repair and increased apoptosis

    International Nuclear Information System (INIS)

    Bigdeli, Bahareh; Goliaei, Bahram; Masoudi-Khoram, Nastaran; Jooyan, Najmeh; Nikoofar, Alireza; Rouhani, Maryam; Haghparast, Abbas; Mamashli, Fatemeh

    2016-01-01

    Introduction: Radiotherapy is a potent treatment against breast cancer, which is the most commonly diagnosed cancer among women. However, the emergence of radioresistance due to increased DNA repair leads to radiotherapeutic failure. Applying polyphenols combined with radiation is a more promising method leading to better survival. Enterolactone, a phytoestrogenic polyphenol, has been reported to inhibit an important radioresistance signaling pathway, therefore we conjectured that enterolactone could enhance radiosensitivity in breast cancer. To assess this hypothesis, radiation response of enterolactone treated MDA-MB-231 and T47D cell lines and corresponding cellular mechanisms were investigated. Methods: Cytotoxicity of enterolactone was measured via MTT assay. Cells were treated with enterolactone before X-irradiation, and clonogenic assay was used to evaluate radiosensitivity. Cell cycle distribution and apoptosis were measured by flow cytometric analysis. In addition, DNA damages and corresponding repair, chromosomal damages, and aberrations were assessed by comet, micronucleus, and cytogenetic assays, respectively. Results: Enterolactone decreased the viability of cells in a concentration- and time dependent manner. Enterolactone significantly enhanced radiosensitivity of cells by abrogating G2/M arrest, impairing DNA repair, and increasing radiation-induced apoptosis. Furthermore, increased chromosomal damages and aberrations were detected in cells treated with enterolactone combined with X-rays than X-ray alone. These effects were more prominent in T47D than MDA-MB-231 cells. Discussion: To our knowledge, this is the first report that enterolactone is a novel radiosensitizer for breast cancer irrespective of estrogen receptor status. Authors propose enterolactone as a candidate for combined therapy to decrease the radiation dose delivered to patients and subsequent side effects. - Highlights: • Enterolactone is proposed to be a novel radiosensitizer for

  5. Enterolactone: A novel radiosensitizer for human breast cancer cell lines through impaired DNA repair and increased apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Bigdeli, Bahareh, E-mail: bhr.bigdeli@ut.ac.ir [Department of Biophysics, Institute of Biochemistry and Biophysics, University of Tehran, 16th Azar St., Enghelab Sq., Tehran (Iran, Islamic Republic of); Goliaei, Bahram, E-mail: goliaei@ut.ac.ir [Department of Biophysics, Institute of Biochemistry and Biophysics, University of Tehran, 16th Azar St., Enghelab Sq., Tehran (Iran, Islamic Republic of); Masoudi-Khoram, Nastaran, E-mail: n.masoudi@alumni.ut.ac.ir [Department of Biophysics, Institute of Biochemistry and Biophysics, University of Tehran, 16th Azar St., Enghelab Sq., Tehran (Iran, Islamic Republic of); Jooyan, Najmeh, E-mail: n.jooyan@ut.ac.ir [Department of Biophysics, Institute of Biochemistry and Biophysics, University of Tehran, 16th Azar St., Enghelab Sq., Tehran (Iran, Islamic Republic of); Nikoofar, Alireza, E-mail: nikoofar@iums.ac.ir [Department of Radiotherapy, Iran University of Medical Sciences (IUMS), Shahid Hemmat Highway, Tehran (Iran, Islamic Republic of); Rouhani, Maryam, E-mail: rouhani@iasbs.ac.ir [Department of Biological Sciences, Institute for Advanced Studies in Basic Sciences (IASBS), Prof. Yousef Sobouti Blvd., Gava Zang, Zanjan (Iran, Islamic Republic of); Haghparast, Abbas, E-mail: Haghparast@sbmu.ac.ir [Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Daneshjo St., Evin, Tehran (Iran, Islamic Republic of); Mamashli, Fatemeh, E-mail: mamashli@ut.ac.ir [Department of Biophysics, Institute of Biochemistry and Biophysics, University of Tehran, 16th Azar St., Enghelab Sq., Tehran (Iran, Islamic Republic of)

    2016-12-15

    Introduction: Radiotherapy is a potent treatment against breast cancer, which is the most commonly diagnosed cancer among women. However, the emergence of radioresistance due to increased DNA repair leads to radiotherapeutic failure. Applying polyphenols combined with radiation is a more promising method leading to better survival. Enterolactone, a phytoestrogenic polyphenol, has been reported to inhibit an important radioresistance signaling pathway, therefore we conjectured that enterolactone could enhance radiosensitivity in breast cancer. To assess this hypothesis, radiation response of enterolactone treated MDA-MB-231 and T47D cell lines and corresponding cellular mechanisms were investigated. Methods: Cytotoxicity of enterolactone was measured via MTT assay. Cells were treated with enterolactone before X-irradiation, and clonogenic assay was used to evaluate radiosensitivity. Cell cycle distribution and apoptosis were measured by flow cytometric analysis. In addition, DNA damages and corresponding repair, chromosomal damages, and aberrations were assessed by comet, micronucleus, and cytogenetic assays, respectively. Results: Enterolactone decreased the viability of cells in a concentration- and time dependent manner. Enterolactone significantly enhanced radiosensitivity of cells by abrogating G2/M arrest, impairing DNA repair, and increasing radiation-induced apoptosis. Furthermore, increased chromosomal damages and aberrations were detected in cells treated with enterolactone combined with X-rays than X-ray alone. These effects were more prominent in T47D than MDA-MB-231 cells. Discussion: To our knowledge, this is the first report that enterolactone is a novel radiosensitizer for breast cancer irrespective of estrogen receptor status. Authors propose enterolactone as a candidate for combined therapy to decrease the radiation dose delivered to patients and subsequent side effects. - Highlights: • Enterolactone is proposed to be a novel radiosensitizer for

  6. Chromosomal radiosensitivity of lymphocytes in South African breast ...

    African Journals Online (AJOL)

    radiosensitivity has been used as an indirect measure of cancer susceptibility. ... studies have shown that breast cancer patients are more sensitive to ionising radiation than healthy individuals. .... There was an effect of ER positivity on the MN.

  7. Co-inhibition of epidermal growth factor receptor and insulin-like growth factor receptor 1 enhances radiosensitivity in human breast cancer cells

    International Nuclear Information System (INIS)

    Li, Ping; Veldwijk, Marlon R; Zhang, Qing; Li, Zhao-bin; Xu, Wen-cai; Fu, Shen

    2013-01-01

    Over-expression of epidermal growth factor receptor (EGFR) or insulin-like growth factor-1 receptor (IGF-1R) have been shown to closely correlate with radioresistance of breast cancer cells. This study aimed to investigate the impact of co-inhibition of EGFR and IGF-1R on the radiosensitivity of two breast cancer cells with different profiles of EGFR and IGF-1R expression. The MCF-7 (EGFR +/−, IGF-1R +++) and MDA-MB-468 (EGFR +++, IGF-1R +++) breast cancer cell lines were used. Radiosensitizing effects were determined by colony formation assay. Apoptosis and cell cycle distribution were measured by flow cytometry. Phospho-Akt and phospho-Erk1/2 were quantified by western blot. In vivo studies were conducted using MDA-MB-468 cells xenografted in nu/nu mice. In MDA-MB-468 cells, the inhibition of IGF-1R upregulated the p-EGFR expression. Either EGFR (AG1478) or IGF-1R inhibitor (AG1024) radiosensitized MDA-MB-468 cells. In MCF-7 cells, radiosensitivity was enhanced by AG1024, but not by AG1478. Synergistical radiosensitizing effect was observed by co-inhibition of EGFR and IGF-1R only in MDA-MB-468 cells with a DMF 10% of 1.90. The co-inhibition plus irradiation significantly induced more apoptosis and arrested the cells at G0/G1 phase in MDA-MB-468 cells. Only co-inhibition of EGFR and IGF-1R synergistically diminished the expression of p-Akt and p-Erk1/2 in MDA-MB-468 cells. In vivo studies further verified the radiosensitizing effects by co-inhibition of both pathways in a MDA-MB-468 xenograft model. Our data suggested that co-inhibition of EGFR and IGF-1R synergistically radiosensitized breast cancer cells with both EGFR and IGF-1R high expression. The approach may have an important therapeutic implication in the treatment of breast cancer patients with high expression of EGFR and IGF-1R

  8. Prediction of radiosensitivity of oral cancers by serial cytological assay of nuclear changes

    International Nuclear Information System (INIS)

    Bhattathiri, N.V.; Nair, K.M.; Bharathykkutty, C.; Prathapan, R.; Chirayathmanjiyil, D.A.

    1998-01-01

    Background and purpose: To identify the relationship between the radiosensitivity of oral cancers and the induction of micronucleation, nuclear budding and multinucleation (polynucleation) evaluated by serial cytology during fractionated radiotherapy. Materials and methods: Forty-four patients with epidermoid cancer of the oral cavity receiving radiotherapy (60 Gy in 25 fractions over 5 weeks) were studied. Serial scrape smears were taken from the tumour before and during radiotherapy and stained by Giemsa and the frequency of micronucleated cells (MNC), nuclear budded cells (NBC) and multinucleated cells (PNC) was evaluated by light microscopy. After a minimum follow-up period of 30 months the patients were classified as having resistant or sensitive tumours, depending on whether the primary tumour had recurred or not within that time. Within-group and between-group analysis on the induction of the above individual parameters and two combined parameters, the micro- or multinucleated cell (MPC) count and the abnormally nucleated cell (ANC) count, was done. The counts were expressed per 1000 uni-nucleated cells. Results: In both groups each parameter showed a statistically significant increase with dose, the increase being higher in the sensitive group. The ANC count showed the greatest increase, the mean counts before treatment and after 28.8 Gy being 24.3 and 157.8 (P<0.0005), respectively, in the sensitive group and 21.0 and 65.2 (P<0.0005), respectively, in the resistant group. After 28.8 Gy the sensitive tumours had significantly higher ANC (P=0.01), MPC (P<0.05) and PNC (P<0.05) counts. Conclusion: The study shows that serial cytological assay of nuclear changes (SCANCing) during radiotherapy is a potentially useful test to predict radiosensitivity. The fact that multinucleation showed the greatest relation with radiosensitivity suggests that injury to the cytokinetic apparatus is important in determining tumour radiosensitivity. (Copyright (c) 1998 Elsevier

  9. Radiosensitivity in breast cancer assessed by the histone γ-H2AX and 53BP1 foci

    International Nuclear Information System (INIS)

    Djuzenova, Cholpon S; Elsner, Ines; Katzer, Astrid; Worschech, Eike; Distel, Luitpold V; Flentje, Michael; Polat, Bülent

    2013-01-01

    High expression of constitutive histone γ-H2AX, a sensitive marker of DNA damage, might be indicative of defective DNA repair pathway or genomic instability. 53BP1 (p53-binding protein 1) is a conserved checkpoint protein with properties of a DNA double-strand breaks sensor. This study explores the relationship between the clinical radiosensitivity of tumor patients and the expression/induction of γ-H2AX and 53BP1 in vitro. Using immunostaining, we assessed spontaneous and radiation-induced foci of γ-H2AX and 53 BP1 in peripheral blood mononuclear cells derived from unselected breast cancer (BC) patients (n=57) undergoing radiotherapy (RT). Cells from apparently healthy donors (n=12) served as references. Non-irradiated cells from controls and unselected BC patients exhibited similar baseline levels of DNA damage assessed by γ-H2AX and 53BP1 foci. At the same time, the γ-H2AX assay of in vitro irradiated cells revealed significant differences between the control group and the group of unselected BC patients with respect to the initial (0.5 Gy, 30 min) and residual (2 Gy, 24 h post-radiation) DNA damage. The numbers of 53BP1 foci analyzed in 35 BC patients were significantly higher than in controls only in case of residual DNA damage. A weak correlation was found between residual foci of both proteins tested. In addition, cells from cancer patients with an adverse acute skin reaction (grade 3) to RT showed significantly increased radiation-induced γ-H2AX foci and their protracted disappearance compared to the group of BC patients with normal skin reaction (grade 0–1). The mean number of γ-H2AX foci after 5 clinical fractions was significantly higher than that before RT, especially in clinically radiosensitive patients. The γ-H2AX assay may have potential for screening individual radiosensitivity of breast cancer patients.

  10. Radiosensitization of non-small cell lung cancer by kaempferol.

    Science.gov (United States)

    Kuo, Wei-Ting; Tsai, Yuan-Chung; Wu, His-Chin; Ho, Yung-Jen; Chen, Yueh-Sheng; Yao, Chen-Han; Yao, Chun-Hsu

    2015-11-01

    The aim of the present study was to determine whether kaempferol has a radiosensitization potential for lung cancer in vitro and in vivo. The in vitro radio-sensitization activity of kaempferol was elucidated in A-549 lung cancer cells by using an MTT (3-(4 5-dimethylthiazol-2-yl)-25-diphenyl-tetrazolium bromide) assay, cell cycle analysis and clonogenic assay. The in vivo activity was evaluated in the BALB/c nude mouse xenograft model of A-549 cells by hematoxylin and eosin staining and immunohistochemistry, and the tumor volume was recorded. Protein levels of the apoptotic pathway were detected by western blot analysis. Treatment with kaempferol inhibited the growth of A-549 cells through activation of apoptotic pathway. However, the same doses did not affect HFL1 normal lung cell growth. Kaempferol induced G2/M cell cycle arrest and the enhancement of radiation-induced death and clonogenic survival inhibition. The in vivo data showed that kaempferol increased tumor cell apoptosis and killing of radiation. In conclusion, the findings demonstrated that kaempferol increased tumor cell killing by radiation in vitro and in vivo through inhibition of the AKT/PI3K and ERK pathways and activation of the mitochondria apoptosis pathway. The results of the present study provided solid evidence that kaempferol is a safe and potential radiosensitizer.

  11. HAP1 gene expression is associated with radiosensitivity in breast cancer cells

    International Nuclear Information System (INIS)

    Wu, Jing; Zhang, Jun-ying; Yin, Li; Wu, Jian-zhong; Guo, Wen-jie; Wu, Jian-feng; Chen, Meng; Xia, You-you; Tang, Jin-hai; Ma, Yong-chao; He, Xia

    2015-01-01

    Highlights: • Overexpression of HAP1 gene promotes apoptosis in MCF-7 cells after irradiation. • HAP1 reduces tumor volume in nude mice xenograft models after irradiation. • HAP1 increases radiosensitivity of breast cancer cells in vitro and vivo. - Abstract: Objectives: The purpose of this study was to investigate the relationship between huntingtin-associated protein1 (HAP1) gene and radiation therapy of breast cancer cells. Methods: HAP1 gene was transfected into breast cancer MCF-7 cells, which was confirmed by quantitative reverse transcription-polymerase chain reaction analysis (qRT-PCR) and Western blot in vitro. The changes of cell radiosensitivity were assessed by colony formation assay. Apoptosis were examined by flow cytometry. The expressions of two radiation-induced genes were evaluated by Western blot. Tumor growth was investigated in nude mice xenograft models in vivo. Results: Our data showed that HAP1 gene expression was significantly increased in HAP1-transfected MCF-7 cells in comparison with the parental cells or negative control cells. The survival rate in MCF-7/HAP1 cells was significantly decreased after irradiation (0, 2, 4, 6, 8 Gy), compared to cells in MCF-7 and MCF-7/Pb groups in vitro. HAP1 gene increased apoptosis in MCF-7 cells after irradiation. Additionally, the tumor volume and weight in MCF-7/HAP1 + RT group were observably lower than in MCF-7/HAP1 group and MCF-7/Pb + RT group. Conclusion: The present study indicated that HAP1 gene expression was related to the radiosensitivity of breast cancer cells and may play an important role in the regulation of cellular radiosensitivity

  12. The role of propranolol as a radiosensitizer in gastric cancer treatment

    Directory of Open Access Journals (Sweden)

    Liao XH

    2018-03-01

    Full Text Available Xinhua Liao, Prakash Chaudhary, Guanglin Qiu, Xiangming Che, Lin Fan General Surgery Department, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, China Purpose: The National Comprehensive Cancer Network guidelines indicate that radiotherapy in gastric cancer shows limited effectiveness at reducing the growth of gastric cancer. Therefore, enhancing the sensitivity and effect of radiotherapy with propranolol, a β-adrenoceptor antagonist, could reduce tumor growth. The role of propranolol as a radiosensitizer has not been adequately studied; therefore, the purpose of the present study is to evaluate the effect of propranolol as a radiosensitizer against gastric cancer in vivo. Methods: Sixty-four male nude mice bearing tumor xenografts were randomly divided into four groups. Cell culture was performed using the human gastric adenocarcinoma cell line SGC-7901. Mice with tumor xenografts were treated with propranolol, isoproterenol, and radiation. The data for tumor weight and volume were obtained for statistical analyses. Furthermore, the expression levels of COX-2, NF-κB, VEGF, and EGFR were examined using immunohistochemical techniques and Western blotting.Results: The growth in the volume and weight of the tumor was lower in mouse models treated with propranolol and radiation therapy compared to the other groups. Decreased expression of NF-κB was also observed in treatment groups where both propranolol and radiation were used, leading to the reduction of COX-2, EGFR, and VEGF expression compared to that in the other groups.Conclusion: The present study indicated that propranolol potentiates the antitumor effects of radiotherapy in gastric cancer by inhibiting NF-κB expression and its downstream genes: VEGF, EGFR, and COX-2. Keywords: propranolol, radiosensitizer, gastric cancer, radiation therapy 

  13. Compliance and toxicity of the hypoxic radiosensitizer nimorazole in the treatment of patients with head and neck squamous cell carcinoma (HNSCC)

    DEFF Research Database (Denmark)

    Metwally, Mohamed Ahmed Hassan; Frederiksen, Katrine Diemer; Overgaard, Jens

    2014-01-01

    Abstract Purpose. To evaluate the compliance and toxicity of the hypoxic radiosensitizer nimorazole in head and neck cancer patients. Methods. A retrospective study of patients with head and neck squamous cell carcinoma (HNSCC), treated in Denmark between 1990 and 2013. All patients treated...... with radical radiotherapy (± chemotherapy) [66-70 Gy; 33-35 fractions; 2 Gy/fraction; 5-6 fractions/week] concomitant with the hypoxic radiosensitizer nimorazole. Nimorazole was administered as oral tablets in doses of approximately 1.2 g/m(2) body surface area in connection with the first of each daily...

  14. Identification of a radiosensitivity signature using integrative metaanalysis of published microarray data for NCI-60 cancer cells

    Directory of Open Access Journals (Sweden)

    Kim Han

    2012-07-01

    Full Text Available Abstract Background In the postgenome era, a prediction of response to treatment could lead to better dose selection for patients in radiotherapy. To identify a radiosensitive gene signature and elucidate related signaling pathways, four different microarray experiments were reanalyzed before radiotherapy. Results Radiosensitivity profiling data using clonogenic assay and gene expression profiling data from four published microarray platforms applied to NCI-60 cancer cell panel were used. The survival fraction at 2 Gy (SF2, range from 0 to 1 was calculated as a measure of radiosensitivity and a linear regression model was applied to identify genes or a gene set with a correlation between expression and radiosensitivity (SF2. Radiosensitivity signature genes were identified using significant analysis of microarrays (SAM and gene set analysis was performed using a global test using linear regression model. Using the radiation-related signaling pathway and identified genes, a genetic network was generated. According to SAM, 31 genes were identified as common to all the microarray platforms and therefore a common radiosensitivity signature. In gene set analysis, functions in the cell cycle, DNA replication, and cell junction, including adherence and gap junctions were related to radiosensitivity. The integrin, VEGF, MAPK, p53, JAK-STAT and Wnt signaling pathways were overrepresented in radiosensitivity. Significant genes including ACTN1, CCND1, HCLS1, ITGB5, PFN2, PTPRC, RAB13, and WAS, which are adhesion-related molecules that were identified by both SAM and gene set analysis, and showed interaction in the genetic network with the integrin signaling pathway. Conclusions Integration of four different microarray experiments and gene selection using gene set analysis discovered possible target genes and pathways relevant to radiosensitivity. Our results suggested that the identified genes are candidates for radiosensitivity biomarkers and that

  15. Non-Surgical Breast-Conserving Treatment (KORTUC-BCT Using a New Radiosensitization Method (KORTUC II for Patients with Stage I or II Breast Cancer

    Directory of Open Access Journals (Sweden)

    Yasuhiro Ogawa

    2015-11-01

    Full Text Available The purpose of the present study was to establish a non-surgical breast-conserving treatment (BCT using KORTUC II radiosensitization treatment. A new radiosensitizing agent containing 0.5% hydrogen peroxide and 0.83% sodium hyaluronate (a CD44 ligand has been developed for intra-tumoral injection into various tumors. This new method, named KORTUC II, was approved by our local ethics committee for the treatment of breast cancer and metastatic lymph nodes. A total of 72 early-stage breast cancer patients (stage 0, 1 patient; stage I, 23; stage II, 48 were enrolled in the KORTUC II trial after providing fully informed consent. The mean age of the patients was 59.7 years. A maximum of 6 mL (usually 3 mL for tumors of less than approximately 3 cm in diameter of the agent was injected into breast tumor tissue twice a week under ultrasonographic guidance. For radiotherapy, hypofraction radiotherapy was administered using a tangential fields approach including an ipsilateral axillary region and field-in-field method; the energy level was 4 MV, and the total radiation dose was 44 Gy administered as 2.75 Gy/fraction. An electron boost of 3 Gy was added three times. Treatment was well tolerated with minimal adverse effects in all 72 patients. No patients showed any significant complications other than mild dermatitis. A total of 24 patients under 75 years old with stage II breast cancer underwent induction chemotherapy (EC and/or taxane prior to KORTUC II treatment, and 58 patients with estrogen receptor-positive tumors also received hormonal therapy following KORTUC II. The mean duration of follow-up as of the end of September 2014 was 51.1 months, at which time 68 patients were alive without any distant metastases. Only one patient had local recurrence and died of cardiac failure at 6.5 years. Another one patient had bone metastases. For two of the 72 patients, follow-up ended after several months following KORTUC II treatment. In conclusion, non

  16. Lethal outcome after pelvic salvage radiotherapy in a patient with prostate cancer due to increased radiosensitivity. Case report and literature review

    Energy Technology Data Exchange (ETDEWEB)

    Fahrig, Antje; Koch, T. [Klinikum Bamberg, Sozialstiftung Bamberg, Klinik und Praxis fuer Radioonkologie und Strahlentherapie, Bamberg (Germany); Lenhart, M. [Klinikum Bamberg, Sozialstiftung Bamberg, Klinik fuer Diagnostische Radiologie, Interventionelle Radiologie und Neuroradiologie, Bamberg (Germany); Rieckmann, P. [Klinikum Bamberg, Sozialstiftung Bamberg, Neurologische Klinik, Bamberg (Germany); Fietkau, R.; Distel, Luitpold; Schuster, B. [Universitaetsklinikum Erlangen, Strahlenklinik, Erlangen (Germany)

    2018-01-15

    In general, late side effects after salvage radiotherapy (RT) for prostate cancer are below 10%. Patients with impaired DNA repair ability and genetic instability can have significantly increased reactions after RT. We present a patient who experienced severe side effects after additive RT for prostate cancer and died from the complications 25 months after RT. Imaging (MR) is shown as well as three-color fluorescence in situ hybridization. The blood sample testing revealed that radiosensitivity was increased by 35-55%. We undertook a review of the literature to give an overview over the tests established that are currently considered useful. This case highlights that the identification of patients with increased radiosensitivity is an important task in radiation protection. Groups of patients who should be screened have to be found and corresponding research facilities have to be set up. (orig.) [German] Generell sind spaete Nebenwirkungen nach additiver Radiotherapie (RT) beim Prostatakarzinom mit deutlich unter 10 % selten. Allerdings haben Patienten mit eingeschraenkter DNA-Reparatur-Kapazitaet und genetischer Instabilitaet ein signifikant erhoehtes Nebenwirkungsrisiko. In diesem Fallbeispiel stellen wir einen Patienten vor, der nach additiver RT wegen Prostatakarzinom massive Nebenwirkungen erlitt und 25 Monate nach der RT daran verstarb. Wir zeigen die Ergebnisse der konsekutiven MR-Untersuchungen und 3-Farben-Fluoreszenz-in-situ-Hybridisierung. Die Blutuntersuchung ergab eine um 35-55 % erhoehte Strahlenempfindlichkeit. Eine aktuelle Literaturrecherche ergab, dass mittlerweile verschiedene Testverfahren zur Untersuchung der Strahlenempfindlichkeit etabliert sind. Das Fallbeispiel zeigt, dass die Identifikation besonders strahlenempfindlicher Patienten ein wichtiges Arbeitsziel im Strahlenschutz ist. Patientenparameter fuer eine erforderliche Testung ueber die bekannten Syndrome hinaus sollten identifizierbar werden. Entsprechende Forschungseinrichtungen sind

  17. Targeted Radiosensitization of ETS Fusion-Positive Prostate Cancer through PARP1 Inhibition

    Directory of Open Access Journals (Sweden)

    Sumin Han

    2013-10-01

    Full Text Available ETS gene fusions, which result in overexpression of an ETS transcription factor, are considered driving mutations in approximately half of all prostate cancers. Dysregulation of ETS transcription factors is also known to exist in Ewing's sarcoma, breast cancer, and acute lymphoblastic leukemia. We previously discovered that ERG, the predominant ETS family member in prostate cancer, interacts with the DNA damage response protein poly (ADP-ribose polymerase 1 (PARP1 in human prostate cancer specimens. Therefore, we hypothesized that the ERG-PARP1 interaction may confer radiation resistance by increasing DNA repair efficiency and that this radio-resistance could be reversed through PARP1 inhibition. Using lentiviral approaches, we established isogenic models of ERG overexpression in PC3 and DU145 prostate cancer cell lines. In both cell lines, ERG overexpression increased clonogenic survival following radiation by 1.25 (±0.07 fold (mean ± SEM and also resulted in increased PARP1 activity. PARP1 inhibition with olaparib preferentially radiosensitized ERG-positive cells by a factor of 1.52 (±0.03 relative to ERG-negative cells (P < .05. Neutral and alkaline COMET assays and immunofluorescence microscopy assessing γ-H2AX foci showed increased short- and long-term efficiencies of DNA repair, respectively, following radiation that was preferentially reversed by PARP1 inhibition. These findings were verified in an in vivo xenograft model. Our findings demonstrate that ERG overexpression confers radiation resistance through increased efficiency of DNA repair following radiation that can be reversed through inhibition of PARP1. These results motivate the use of PARP1 inhibitors as radiosensitizers in patients with localized ETS fusion-positive cancers.

  18. Potential of radiosensitizing agents in cancer chemo-radiotherapy

    Directory of Open Access Journals (Sweden)

    Girdhani S

    2005-01-01

    Full Text Available Potential of herbs and other plant-based formulations have been increasingly recognized in prevention and treatment of human diseases including cancer. There exist enormous prospect for screening and evaluation of herbal/plant products for developing effective radiosensitization and radioprotection relevant to nuclear research program. Investigations in our laboratory have focused on the mechanism of activity of variety of anticancer and antioxidant agents, namely, Eugenol, (EU, Ellagic acid (EA, Triphala (TPL, Tocopherol Succinate (TOS and Arachidonic acid on normal and cancer cells with view to design effective protocols in practical radioprotection and cancer radiotherapy. This paper is mainly focused on studies on cytotoxic effects on cancer cell lines. Results have shown that these agents produced radiosensitizing action involving oxidative damage, membrane alteration and damage to nucleic acid in various human cell lines. Studies were performed employing fluorescence probes and electron spin resonance methods and gel electrophoresis protocols. It has been found that cytotoxic effect was induced by initiating membrane oxidative damage and by triggering intracellular generation of reactive oxygen species (ROS by gamma radiation in combination with phytochemicals like TPL, EA and TOS in tumor cell line Ehrlich Ascites (EAC, Human cervical (HeLa and breast (MCF-7 cells. Membrane damage and ROS generation was measured by DPH and DCF-FDA fluorescent probes respectively after exposure to low to moderate doses of gamma radiation. This talk will present the cytotoxic effects of phytochemicals in combination with ionizing radiation. It is emphasized that modulation of membrane peroxidative damage and intra cellular ROS may help achieve efficient killing of cancer cells which may provide a new approach to developing effective treatment of cancer.

  19. Effect of BRCA1 on radiosensitivity of different lung cancer cells

    International Nuclear Information System (INIS)

    Zhang Huiwen; Wang Miao; Wang Yansu; Ren Hang; Xu Jiaying; Jiao Yang; Fan Saijun; Meng Qinghui

    2011-01-01

    Objective: To investigate the effects BRCA1 on sensitivity of lung cancer cells to γ-irradiation. Methods: A mammalian expression pcDNA3 vectors encoding a full-length of BRCA1 cDNA and BRCA1 siRNA were transfected into lung cancer cells. Western blot, MTT and clonogenic assays were used to determine BRCA1 protein expression and cell survival following γ-irradiation respectively. Results: There is a close relationship between BRCA1 level and radiosensitivity in different lung cancer cell lines. Compared with the control cells transfected with the 'empty' pcDNA3 vector and parental cells, the more survival of cells transfected with BRCA1 was observed after irradiation. The BRCA1-caused radioresistance were observed in both A549 and HTB-58 lung cancer lines. However, NIH-H2170 cells transfected with BRCA1 siRNA became more sensitive to γ-irradiation. Conclusion: This study, for the first time, demonstrates that the alteration of BRCA1 expression significantly affects radiosensitivity of lung cancer, indicating that BRCA1 may be an important mediator in radiotherapy of lung cancer cells. (authors)

  20. Study of radiosensitization of chloroquine on esophageal cancer cell line

    International Nuclear Information System (INIS)

    Yuan Xiaoli; Li Tao; Huang Jianming; Zha Xiao; Deng Bifang; Lang Jinyi

    2014-01-01

    Objective: To investigate the possibility of chloroquine radiosensitization of esophageal cancer cell line TE-1 and its further mechanism. Methods: Effect of chloroquine on cell viability of TE-1 cells was determined by MTT method. Expression of LC3, Beclin-1 and formation of acidic vesicular organelles (AVOs) were determined by Western blot, and fluorescence staining with Lyso-Tracker Red DND-99, respectively. Clonogenic survival of TE-1 cells was examined by clonogenic forming assay. Results: Chloroquine showed dose-dependent inhibition of TE-1 cell growth, and its values of IC_5_0 and IC_1_0 were (72.33±5.28) and (15.42±3.33) μmol/L, respectively. The expression of Beclin-1 and LC3-II/I markedly increased in irradiated TE-1 cells. The addition of chloroquine with IC_1_0 concentration significantly reduced the fluorescence and intensity of AVOs accumulation in the cytoplasm of TE-1 cells. Clonogenic survival fraction decreased obviously in TE-1 cells with addition of chloroquine after radiation and the value of SERD0 was 1.439. Conclusions: Chloroquine could radiosensitize esophageal cancer cells by blocking autophagy-lysosomal pathway and be used as a potential radiosensitizing strategy. (authors)

  1. Low-Dose Hyper-Radiosensitivity Is Not a Common Effect in Normal Asynchronous and G2-Phase Fibroblasts of Cancer Patients

    International Nuclear Information System (INIS)

    Słonina, Dorota; Biesaga, Beata; Janecka, Anna; Kabat, Damian; Bukowska-Strakova, Karolina; Gasińska, Anna

    2014-01-01

    Purpose: In our previous study, using the micronucleus assay, a low-dose hyper-radiosensitivity (HRS)-like phenomenon was observed for normal fibroblasts of 2 of the 40 cancer patients investigated. In this article we report, for the first time, the survival response of primary fibroblasts from 25 of these patients to low-dose irradiation and answer the question regarding the effect of G2-phase enrichment on HRS elicitation. Methods and Materials: The clonogenic survival of asynchronous as well as G2-phase enriched fibroblast populations was measured. Separation of G2-phase cells and precise cell counting was performed using a fluorescence-activated cell sorter. Sorted and plated cells were irradiated with single doses (0.1-4 Gy) of 6-MV x-rays. For each patient, at least 4 independent experiments were performed, and the induced-repair model was fitted over the whole data set to confirm the presence of HRS effect. Results: The HRS response was demonstrated for the asynchronous and G2-phase enriched cell populations of 4 patients. For the rest of patients, HRS was not defined in either of the 2 fibroblast populations. Thus, G2-phase enrichment had no effect on HRS elicitation. Conclusions: The fact that low-dose hyper-radiosensitivity is not a common effect in normal human fibroblasts implies that HRS may be of little consequence in late-responding connective tissues with regard to radiation fibrosis

  2. Chromosomal radiosensitivity in patients with multiple sclerosis

    International Nuclear Information System (INIS)

    Milenkova, Maria; Milanov, Ivan; Kmetska, Ksenia; Deleva, Sofia; Popova, Ljubomira; Hadjidekova, Valeria; Groudeva, Violeta; Hadjidekova, Savina; Domínguez, Inmaculada

    2013-01-01

    Highlights: • We studied radiosensitivity to in vitro γ-irradiated lymphocytes from MS patients. • Immunotherapy in RRMS patients reduced the yield of radiation induced MN. • The group of treated RRMS accounts for the low radiosensitivity in MS patients. • Spontaneous yield of MN was similar in treated and untreated RRMS patients. - Abstract: Multiple sclerosis is a clinically heterogeneous autoimmune disease leading to severe neurological disability. Although during the last years many disease-modifying agents as treatment options for multiple sclerosis have been made available, their mechanisms of action are still not fully determined. In the present study radiosensitivity in lymphocytes of patients with relapsing–remitting multiple sclerosis, secondary progressive multiple sclerosis and healthy controls was investigated. Whole blood cultures from multiple sclerosis patients and healthy controls were used to analyze the spontaneous and radiation-induced micronuclei in binucleated lymphocytes. A subgroup of patients with relapsing–remitting multiple sclerosis was treated with immunomodulatory agents, interferon β or glatiramer acetate. The secondary progressive multiple sclerosis patients group was not receiving any treatment. Our results reveal that the basal DNA damage was not different between relapsing–remitting and secondary progressive multiple sclerosis patients, and healthy controls. No differences between gamma-irradiation induced micronuclei frequencies in binucleated cells from relapsing–remitting and secondary progressive multiple sclerosis patients, and healthy controls were found either. Nevertheless, when we compared the radiation induced DNA damage in binucleated cells from healthy individuals with the whole group of patients, a reduction in the frequency of micronuclei was obtained in the patients group. Induced micronuclei yield was significantly lower in the irradiated samples from treated relapsing–remitting multiple

  3. Chromosomal radiosensitivity in patients with multiple sclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Milenkova, Maria; Milanov, Ivan; Kmetska, Ksenia [III Neurological Clinic, University Hospital Saint Naum, Sofia (Bulgaria); Deleva, Sofia; Popova, Ljubomira; Hadjidekova, Valeria [Laboratory of Radiation Genetics, NCRRP, Sofia (Bulgaria); Groudeva, Violeta [Department of Diagnostic Imaging, University Hospital St. Ekaterina, Sofia (Bulgaria); Hadjidekova, Savina [Department of Medical Genetics, Medical University, Sofia (Bulgaria); Domínguez, Inmaculada, E-mail: idomin@us.es [Department of Cell Biology, Faculty of Biology, University of Seville, Avda. Reina Mercedes 6, 41012 (Spain)

    2013-09-15

    Highlights: • We studied radiosensitivity to in vitro γ-irradiated lymphocytes from MS patients. • Immunotherapy in RRMS patients reduced the yield of radiation induced MN. • The group of treated RRMS accounts for the low radiosensitivity in MS patients. • Spontaneous yield of MN was similar in treated and untreated RRMS patients. - Abstract: Multiple sclerosis is a clinically heterogeneous autoimmune disease leading to severe neurological disability. Although during the last years many disease-modifying agents as treatment options for multiple sclerosis have been made available, their mechanisms of action are still not fully determined. In the present study radiosensitivity in lymphocytes of patients with relapsing–remitting multiple sclerosis, secondary progressive multiple sclerosis and healthy controls was investigated. Whole blood cultures from multiple sclerosis patients and healthy controls were used to analyze the spontaneous and radiation-induced micronuclei in binucleated lymphocytes. A subgroup of patients with relapsing–remitting multiple sclerosis was treated with immunomodulatory agents, interferon β or glatiramer acetate. The secondary progressive multiple sclerosis patients group was not receiving any treatment. Our results reveal that the basal DNA damage was not different between relapsing–remitting and secondary progressive multiple sclerosis patients, and healthy controls. No differences between gamma-irradiation induced micronuclei frequencies in binucleated cells from relapsing–remitting and secondary progressive multiple sclerosis patients, and healthy controls were found either. Nevertheless, when we compared the radiation induced DNA damage in binucleated cells from healthy individuals with the whole group of patients, a reduction in the frequency of micronuclei was obtained in the patients group. Induced micronuclei yield was significantly lower in the irradiated samples from treated relapsing–remitting multiple

  4. Radiation induced chromosomal instability in lymphocytes of cancer patients

    International Nuclear Information System (INIS)

    Sudo, H.; Sagara, M.; Ban, S.; Noda, S.; Iwakawa, M.; Harada, Y.; Imai, T.; Cologne, J.B.

    2003-01-01

    Full text: Cytokinesis-blocked micronucleus (CBMN) assay has been extensively used to evaluate the radiation sensitivity of human individuals. Using the CBMN assay, Scott et al (1998, 1999) demonstrated that a fraction of radiosensitive individuals in breast cancer case population was larger than in normal individual population. However, Vral et al were very skeptical about the Scott et al's findings (2002). Under the approval from the ethical committee of NIRS, peripheral blood was obtained from 46 normal healthy females, 131 breast cancer patients, 32 cervical cancer patients and 7 female head and neck cancer patients. Radiosensitivity of T-lymphocytes was assessed by using a CBMN assay. The frequencies of MN per binucleated cell in healthy donors were 0.031(±0.010) and 0.151(±0.066) for cells treated before and after X-ray-irradiation (2Gy), respectively. Spontaneous MN frequencies in cancer patients were significantly higher than healthy donors (p < 0.001). Radiation sensitivities of breast- and head and neck-cancer patients were significantly higher than normal individuals (p < 0.001). Cervical cancer patients were more resistant to irradiation than healthy donors, though the number of cases for statistical analysis was small. (p < 0.001). We are considering that the HPV infection affected the radiosensitivity of cervical cancer cases. Because it is widely believed that one key mechanism which leads to spontaneous micronucleus formation involves an imbalance of chromosomal segregation and a chromosomal instability in patients' lymphocytes might be greater than that in normal individuals' lymphocytes. Recently, Kuschel et al (2002) demonstrated that ratios in two SNPs on XRCC3 were significantly different between cancer patients and healthy females. Then, we can suppose that the radiation-related genes with low penetrance may be involved in tumorigenesis of mammary- and head and neck-cells, and also, in patients' radiation susceptibility

  5. Andrographolide radiosensitizes human esophageal cancer cell line ECA109 to radiation in vitro.

    Science.gov (United States)

    Wang, Z-M; Kang, Y-H; Yang, X; Wang, J-F; Zhang, Q; Yang, B-X; Zhao, K-L; Xu, L-P; Yang, L-P; Ma, J-X; Huang, G-H; Cai, J; Sun, X-C

    2016-01-01

    To explore the radiosensitivity of andrographolide on esophageal cancer cell line ECA109. The inhibition effects of andrographolide were measured using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium (MTT) assay. Clonogenic survival assay was used to evaluate the effects of andrographolide on the radiosensitivity of esophageal cancer cells. Immunofluorescence was employed to examine Bax expression. The changes in cell cycle distribution and apoptosis were assayed using flow cytometry. The expression of NF-κb/Cleaved-Caspase3/Bax/Bcl-2 was measured using Western blot analysis. DNA damage was detected via γ-H2AX foci counting. With a clear dose and time effects, andrographolide was found to inhibit the proliferation of esophageal cell line ECA109. The results of the clonogenic survival assay show that andrographolide could markedly enhance radiosensitivity (P Andrographolide caused a dose-dependent increase in Cleaved-Caspase3/Bax protein expression and a decrease in Bcl-2/NF-κb expression. Apoptosis in andrographolide-treated ECA-109 increased significantly compared with the apoptosis in the simple drug and radiation combined with drug groups (P andrographolide combined with radiation group increased the number of DNA double chain breaks. Andrographolide can increase the radiosensitivity of esophageal cell line ECA109. This result may be associated with the decrease in the NF-κb level and the induced apoptosis of esophageal cancer cells. © 2014 International Society for Diseases of the Esophagus.

  6. Radiosensitivity of primary tumour cultures as a determinant of curability of human head and neck cancers

    International Nuclear Information System (INIS)

    Peters, L.J.; Tofilon, P.J.; Goepfert, H.; Brock, W.A.

    1989-01-01

    Between November 1985 and November 1987, 31 patients with squamous cell carcinomas of the head and neck who were treated on protocol by surgery and post-operative radiotherapy at the University of Texas M. D. Anderson Cancer Center had radiosensitivity measurements made on primary cultures of the surgical specimens using the Adhesive Tumour Cell Culture System. The parameter of cell survival at 2 Gy (S 2 ) was correlated with the clinical outcome independently of pathological risk factors. All five recurrences have been in patients with S 2 values >0.3 (p = 0.08). Evidence of significant intratumoral heterogeneity of cellular radiosensitivity in vitro was demonstrated in one of four cultures tested. Mathematical modelling suggests that in the absence of marked heterogeneity, the S 2 parameter is likely to be more robust than other radiobiologically based assays in predicting clinical treatment outcome. (author)

  7. Enhancement of P53-Mutant Human Colorectal Cancer Cells Radiosensitivity by Flavonoid Fisetin

    International Nuclear Information System (INIS)

    Chen Wenshu; Lee Yijang; Yu Yichu; Hsaio Chinghui

    2010-01-01

    Purpose: The aim of this study was to investigate whether fisetin is a potential radiosensitizer for human colorectal cancer cells, which are relatively resistant to radiotherapy. Methods and Materials: Cell survival was examined by clonogenic survival assay, and DNA fragmentation was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay. The effects of treatments on cell cycle distribution and apoptosis were examined by flow cytometry. Western blot analysis was performed to ascertain the protein levels of γ-H2AX, phospho-Chk2, active caspase-3, PARP cleavage, phospho-p38, phospho-AKT, and phospho-ERK1/2. Results: Fisetin pretreatment enhanced the radiosensitivity of p53-mutant HT-29 human colorectal cancer cells but not human keratocyte HaCaT cells; it also prolonged radiation-induced G 2 /M arrest, enhanced radiation-induced cell growth arrest in HT-29 cells, and suppressed radiation-induced phospho-H2AX (Ser-139) and phospho-Chk2 (Thr-68) in p53-mutant HT-29 cells. Pretreatment with fisetin enhanced radiation-induced caspase-dependent apoptosis in HT-29 cells. Fisetin pretreatment augmented radiation-induced phosphorylation of p38 mitogen-activated protein kinase, which is involved in caspase-mediated apoptosis, and SB202190 significantly reduced apoptosis and radiosensitivity in fisetin-pretreated HT-29 cells. By contrast, both phospho-AKT and phospho-ERK1/2, which are involved in cell proliferation and antiapoptotic pathways, were suppressed after irradiation combined with fisetin pretreatment. Conclusions: To our knowledge, this study is the first to provide evidence that fisetin exerts a radiosensitizing effect in p53-mutant HT-29 cells. Fisetin could potentially be developed as a novel radiosensitizer against radioresistant human cancer cells.

  8. Radiosensitizing Silica Nanoparticles Encapsulating Docetaxel for Treatment of Prostate Cancer.

    Science.gov (United States)

    Belz, Jodi; Castilla-Ojo, Noelle; Sridhar, Srinivas; Kumar, Rajiv

    2017-01-01

    The applications of nanoparticles in oncology include enhanced drug delivery, efficient tumor targeting, treatment monitoring, and diagnostics. The "theranostic properties" associated with nanoparticles have shown enhanced delivery of chemotherapeutic drugs with superior imaging capabilities and minimal toxicities. In conventional chemotherapy, only a fraction of the administered drug reaches the tumor site or cancer cells. For successful translation of these formulations, it is imperative to evaluate the design and properties of these nanoparticles. Here, we describe the design of ultra-small silica nanoparticles to encapsulate a radiosensitizing drug for combined chemoradiation therapy. The small size of nanoparticles allows for better dispersion and uptake of the drug within the highly vascularized tumor tissue. Silica nanoparticles are synthesized using an oil-in-water microemulsion method. The microemulsion method provides a robust synthetic route in which the inner hydrophobic core is used to encapsulate chemotherapy drug, docetaxel while the outer hydrophilic region provides dispersibility of the synthesized nanoparticles in an aqueous environment. Docetaxel is commonly used for treatment of resistant or metastatic prostate cancer, and is known to have radiosensitizing properties. Here, we describe a systematic approach for synthesizing these theranostic nanoparticles for application in prostate cancer.

  9. Association Between Genetic Polymorphisms in the XRCC1, XRCC3, XPD, GSTM1, GSTT1, MSH2, MLH1, MSH3, and MGMT Genes and Radiosensitivity in Breast Cancer Patients

    International Nuclear Information System (INIS)

    Mangoni, Monica; Bisanzi, Simonetta; Carozzi, Francesca; Sani, Cristina; Biti, Giampaolo; Livi, Lorenzo; Barletta, Emanuela; Costantini, Adele Seniori; Gorini, Giuseppe

    2011-01-01

    Purpose: Clinical radiosensitivity varies considerably among patients, and radiation-induced side effects developing in normal tissue can be therapy limiting. Some single nucleotide polymorphisms (SNPs) have been shown to correlate with hypersensitivity to radiotherapy. We conducted a prospective study of 87 female patients with breast cancer who received radiotherapy after breast surgery. We evaluated the association between acute skin reaction following radiotherapy and 11 genetic polymorphisms in DNA repair genes: XRCC1 (Arg399Gln and Arg194Trp), XRCC3 (Thr241Met), XPD (Asp312Asn and Lys751Gln), MSH2 (gIVS12-6T>C), MLH1 (Ile219Val), MSH3 (Ala1045Thr), MGMT (Leu84Phe), and in damage-detoxification GSTM1 and GSTT1 genes (allele deletion). Methods and Materials: Individual genetic polymorphisms were determined by polymerase chain reaction and single nucleotide primer extension for single nucleotide polymorphisms or by a multiplex polymerase chain reaction assay for deletion polymorphisms. The development of severe acute skin reaction (moist desquamation or interruption of radiotherapy due to toxicity) associated with genetic polymorphisms was modeled using Cox proportional hazards, accounting for cumulative biologically effective radiation dose. Results: Radiosensitivity developed in eight patients and was increased in carriers of variants XRCC3-241Met allele (hazard ratio [HR] unquantifiably high), MSH2 gIVS12-6nt-C allele (HR = 53.36; 95% confidence intervals [95% CI], 3.56-798.98), and MSH3-1045Ala allele (HR unquantifiably high). Carriers of XRCC1-Arg194Trp variant allele in combination with XRCC1-Arg399Gln wild-type allele had a significant risk of radiosensitivity (HR = 38.26; 95% CI, 1.19-1232.52). Conclusions: To our knowledge, this is the first report to find an association between MSH2 and MSH3 genetic variants and the development of radiosensitivity in breast cancer patients. Our findings suggest the hypothesis that mismatch repair mechanisms may be

  10. Dimethoxycurcumin, a metabolically stable analogue of curcumin enhances the radiosensitivity of cancer cells: Possible involvement of ROS and thioredoxin reductase

    Energy Technology Data Exchange (ETDEWEB)

    Jayakumar, Sundarraj; Patwardhan, R.S.; Pal, Debojyoti [Radiation Biology & Health Sciences Division, Modular Laboratories, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Sharma, Deepak [Radiation Biology & Health Sciences Division, Modular Laboratories, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094 (India); Sandur, Santosh K., E-mail: sskumar@barc.gov.in [Radiation Biology & Health Sciences Division, Modular Laboratories, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094 (India)

    2016-09-09

    Dimethoxycurcumin (DIMC), a structural analogue of curcumin, has been shown to have more stability, bioavailability, and effectiveness than its parent molecule curcumin. In this paper the radiosensitizing effect of DIMC has been investigated in A549 lung cancer cells. As compared to its parent molecule curcumin, DIMC showed a very potent radiosensitizing effect as seen by clonogenic survival assay. DIMC in combination with radiation significantly increased the apoptosis and mitotic death in A549 cells. This combinatorial treatment also lead to effective elimination of cancer stem cells. Further, there was a significant increase in cellular ROS, decrease in GSH to GSSG ratio and also significant slowdown in DNA repair when DIMC was combined with radiation. In silico docking studies and in vitro studies showed inhibition of thioredoxin reductase enzyme by DIMC. Overexpression of thioredoxin lead to the abrogation of radiosensitizing effect of DIMC underscoring the role of thioredoxin reductase in radiosensitization. Our results clearly demonstrate that DIMC can synergistically enhance the cancer cell killing when combined with radiation by targeting thioredoxin system. - Highlights: • DIMC enhances radiosensitivity of cancer cells by inducing cell death. • DIMC with radiation disrupted the cellular redox and targeted cancer stem cells. • DNA repair is hampered when cells are treated with DIMC. • DIMC inhibited thioredoxin reductase in cancer cells.

  11. Dimethoxycurcumin, a metabolically stable analogue of curcumin enhances the radiosensitivity of cancer cells: Possible involvement of ROS and thioredoxin reductase

    International Nuclear Information System (INIS)

    Jayakumar, Sundarraj; Patwardhan, R.S.; Pal, Debojyoti; Sharma, Deepak; Sandur, Santosh K.

    2016-01-01

    Dimethoxycurcumin (DIMC), a structural analogue of curcumin, has been shown to have more stability, bioavailability, and effectiveness than its parent molecule curcumin. In this paper the radiosensitizing effect of DIMC has been investigated in A549 lung cancer cells. As compared to its parent molecule curcumin, DIMC showed a very potent radiosensitizing effect as seen by clonogenic survival assay. DIMC in combination with radiation significantly increased the apoptosis and mitotic death in A549 cells. This combinatorial treatment also lead to effective elimination of cancer stem cells. Further, there was a significant increase in cellular ROS, decrease in GSH to GSSG ratio and also significant slowdown in DNA repair when DIMC was combined with radiation. In silico docking studies and in vitro studies showed inhibition of thioredoxin reductase enzyme by DIMC. Overexpression of thioredoxin lead to the abrogation of radiosensitizing effect of DIMC underscoring the role of thioredoxin reductase in radiosensitization. Our results clearly demonstrate that DIMC can synergistically enhance the cancer cell killing when combined with radiation by targeting thioredoxin system. - Highlights: • DIMC enhances radiosensitivity of cancer cells by inducing cell death. • DIMC with radiation disrupted the cellular redox and targeted cancer stem cells. • DNA repair is hampered when cells are treated with DIMC. • DIMC inhibited thioredoxin reductase in cancer cells.

  12. Effect of primarily cultured human lung cancer-associated fibroblasts on radiosensitivity of lung cancer cells

    International Nuclear Information System (INIS)

    Ji Xiaoqin; Ji Jiang; Chen Yongbing; Shan Fang; Lu Xueguan

    2014-01-01

    Objective: To investigate the effect of human lung cancer-associated fibroblasts (CAF) on the radiosensitivity of lung cancer cells when CAF is placed in direct contact co-culture with lung cancer cells. Methods: Human lung CAF was obtained from fresh human lung adenocarcinoma tissue specimens by primary culture and subculture and was then identified by immunofluorescence staining. The CAF was placed in direct contact co-culture with lung cancer A 549 and H 1299 cells, and the effects of CAF on the radiosensitivity of A 549 and H 1299 cells were evaluated by colony-forming assay. Results: The human lung CAF obtained by adherent culture could stably grow and proliferate, and it had specific expression of α-smooth muscle actin, vimentin, and fibroblast activation protein,but without expression of cytokeratin-18. The plating efficiency (PE, %) of A 549 cells at 0 Gy irradiation was (20.0 ± 3.9)% when cultured alone versus (32.3 ± 5.5)% when co-cultured with CAF (t=3.16, P<0.05), and the PE of H 1299 cells at 0 Gy irradiation was (20.6 ± 3.1)% when cultured alone versus (35.2 ± 2.3)% when co-cultured with CAF (t=6.55, P<0.05). The cell survival rate at 2 Gy irradiation (SF 2 ) of A 549 cells was 0.727 ±0.061 when cultured alone versus 0.782 ± 0.089 when co-cultured with CAF (t=0.88, P>0.05), and the SF 2 of H 1299 cells was 0.692 ±0.065 when cultured alone versus 0.782 ± 0.037 when co-cultured with CAF (t=2.08, P>0.05). The protection enhancement ratios of human lung CAF for A 549 cells and H 1299 cells were 1.29 and 1.25, respectively. Conclusions: Human lung CAF reduces the radiosensitivity of lung cancer cells when placed in direct contact co-culture with them, and the radioprotective effect may be attributed to CAF promoting the proliferation of lung cancer cells. (authors)

  13. AT-406, an IAP inhibitor, activates apoptosis and induces radiosensitization of normoxic and hypoxic cervical cancer cells.

    Science.gov (United States)

    Lu, Jing; Qin, Qin; Zhan, Liang-Liang; Liu, Jia; Zhu, Hong-Cheng; Yang, Xi; Zhang, Chi; Xu, Li-Ping; Liu, Zhe-Ming; Wang, Di; Cui, He-Qing; Meng, Ciu-Ciu; Cai, Jing; Cheng, Hong-Yan; Sun, Xin-Chen

    2014-01-01

    IAP antagonists increased the antitumor efficacy of X-irradiation in some types of cancers, but their effects on hypoxic cancer cells remain unclarified. We aims to investigate the radiosensitizing effect of an IAP inhibitor AT-406 on cervical cancer cell lines under both normoxia and hypoxia conditions. Hela and Siha cells were treated to investigate the effects of drug administration on cell proliferation, apoptosis, and radiosensitivity. Western blot analysis was used to determine the role of AT-406 in inhibition of IAPs. The pathway of apoptosis was characterized by caspases activity assay. AT-406 potently sensitized Hela cells but not Siha cells to radiation under normoxia. Notably, the radiosensitizing effect of AT-406 on hypoxic cells was more evident than on normoxic cells in both cell lines. Further mechanism studies by western blot showed that under normoxia AT-406 decreased the level of cIAP1 in Hela cells in a dose-dependent manner; while additional downregulation of XIAP expression was induced by AT-406 treatment under hypoxia in both cell lines. Finally, AT-406 works on both extrinsic death receptor and intrinsic mitochondrial apoptosis pathways to activate apoptosis. Totally, AT-406 acts as a strong radiosensitizer in human cervical cancer cells, especially in hypoxic condition.

  14. antiEGFR conjugated gold nanoparticles for increasing radiosensitivity in lung cancer cells

    International Nuclear Information System (INIS)

    Pujari, Geetanjali; Sarma, Asitikantha; Avasthi, Devesh K.

    2014-01-01

    One of the set back that lies in lung cancer treatment is the over expression of Epidermal Growth Factor Receptor (EGFR). EGFR is a transmembrane receptor that is highly expressed in lung cancer that leads to cell survival, proliferation and spread of the disease. Over the years, EGFR inhibitors, monoclonal antibodies, are being used in combination with radiotherapy in lung cancer patients so as to achieve better results. In the recent time, application of Au nanoparticles (AuNPs) in diagnosis and treatment of cancer has been extensively used in biomedical research. Among various applications, there is considerable use of AuNPs seen on the dose enhancement effect (radiosensitization) in radiation therapy of cancer. The conjugation of AuNP with monoclonal antibody antiEGFR (antiEGFR-AuNP) may provide excellent agent to sensitize the cells to heavy ion radiation. We synthesized AuNPs by citrate reduction method. Most of AuNPs were in the size range of 6-8 nm as studies by Transmission Electron Microscope (TEM). These AuNPs were found to be non toxic in A549 cells and thus biocompatible. Further, we conjugated AuNPs with antiEGFR (antiEGFR-AuNP). The conjugation was confirmed by UV-Vis spectroscopy. A549 cells were treated with antiEGFR-AuNP. TEM was carried out of ultrathin cross sections of antiEGFR-AuNP treated A549 cells to check the attachment internalization of AuNPs. We observed that the AuNPs are attached on the cell membrane as well as internalized in cytoplasm. Upon exposure of antiEGFR-AuNP treated cells to heavy ion 12 C beam, showed increase in radiosensitization as studied by survival assay and MTT assay. We will also explain the EGFR expression and cell cycle proliferation in A549 cells upon heavy ion beam irradiation of these. The study aims to overcome the current limitations of cancer-targeted therapies and improve the treatment modality of lung cancer. (author)

  15. Predictive radiosensitivity tests in human lymphocytes

    International Nuclear Information System (INIS)

    Di Giorgio, Marina; Vallerga, Maria B.; Taja, Maria R.; Sardi, M.; Busto, E.; Mairal, L.; Roth, B.; Menendez, P.; Bonomi, M.

    2004-01-01

    Individual radiosensitivity is an inherent characteristic, associated with an abnormally increased reaction to ionising radiation of both the whole body and cells derived from body tissues. Human population is not uniform in its radiation sensitivity. Radiosensitive sub-groups exist, which would suffer an increased incidence of both deterministic and stochastic effects. Clinical studies have suggested that a large part of the spectrum of normal tissue reaction may be due to differences in individual radiosensitivity. The identification of such sub-groups should be relevant for radiation therapy and radiation protection purposes. It is suggested that DNA repair mechanisms are involved. Consequently, the characterization of DNA repair in lymphocytes through cytokinesis blocked micronucleus (MN) and alkaline single-cell microgel electrophoresis (comet) assays could be a suitable approache to evaluate individual radiosensitivity in vitro. The aims of this study were: 1) To assess the in vitro radiosensitivity of peripheral blood lymphocytes from two groups of cancer patients (prospectively and retrospectively studied), using MN and comet assays, in comparison with the clinical radiation reaction and 2) To test the predictive potential of both techniques for the identification of radiosensitivity sub-groups. 38 cancer patients receiving radiation therapy were enrolled in this study. 19 patients were evaluated prior, mid-way and on completion of treatment (prospective group) and 19 patients were evaluated about 6-18 month after radiotherapy (retrospective group). Cytogenetic data from the prospective group were analysed using a mathematical model to evaluate the attenuation of the cytogenetic effect as a function of the time between a single exposure and blood sampling, estimating a cytogenetic recovery factor k. In the retrospective group, blood samples were irradiated in vitro with 0 (control) or 2 Gy and evaluated using MN test. Cytogenetic data were analysed

  16. Radio-sensitization of WRN helicase deficient cancer cells by targeting homologous recombination pathway

    International Nuclear Information System (INIS)

    Gupta, Pooja; Saha, Bhaskar; Patro, Birija Sankar; Chattopadhyay, Subrata

    2016-01-01

    Ionizing radiation (IR) induced DNA double-strand breaks (DSBs) are primarily repaired by non-homologous end joining (NHEJ). However, it is well established that a subset DSBs which are accumulated in IR-induced G2 phase are dependent on homologous recombination (HR). DNA repair deficient tumor cells have been shown to accumulate high levels of DNA damage. Consequently, these cells become hyperdependent on DNA damage response pathways, including the CHK1-kinase-mediated HR-repair. These observations suggest that DNA repair deficient tumors should exhibit increased radio-sensitivity under HR inhibition. Genetic defects leading to functional loss of werner (WRN) protein is associated with genomic instability and increased cancer incidence. WRN function is known to be abrogated in several human cancer cells due to hypermethylation of CpGisland-promoter and transcriptional silencing of WRN gene. In the current investigation, using isogenic pairs of cell lines differing only in the WRN function, we showed that WRN-deficient cell lines were hyper-radiosensitive to CHK1 pharmacologic inhibition. Here, we found that unrepaired DSB was drastically increased in WRN-deficient cells vis-à-vis WRN-proficient cells in response to IR and CHK1 inhibitor (CHK1i). Our results revealed a marginal role of NHEJ pathway accountable for the radio-sensitivity of WRN-deficient cells. Interestingly, silencing CTIP, a HR protein required for RAD51 loading, significantly abrogated the CHK1i-mediated radiosensitivity in WRN-deficient cells. Silencing of WRN or CTIP individually led to no significant difference in the extent of DNA end resection, as required during HR pathway. Imperatively, our results revealed that WRN and CTIP together play a complementary role in executing DNA end resection during HR-mediated repair of IR induced DSBs. Altogether, our data indicated that inhibition of IR-induced HR pathway at RAD51 loading, but not at DSB end resection, make the WRN-deficient cancer cells

  17. DNMT (DNA methyltransferase) inhibitors radiosensitize human cancer cells by suppressing DNA repair activity

    International Nuclear Information System (INIS)

    Kim, Hak Jae; Kim, Jin Ho; Chie, Eui Kyu; Da Young, Park; Kim, In Ah; Kim, Il Han

    2012-01-01

    Histone modifications and DNA methylation are two major factors in epigenetic phenomenon. Unlike the histone deacetylase inhibitors, which are known to exert radiosensitizing effects, there have only been a few studies thus far concerning the role of DNA methyltransferase (DNMT) inhibitors as radiosensitizers. The principal objective of this study was to evaluate the effects of DNMT inhibitors on the radiosensitivity of human cancer cell lines, and to elucidate the mechanisms relevant to that process. A549 (lung cancer) and U373MG (glioblastoma) cells were exposed to radiation with or without six DNMT inhibitors (5-azacytidine, 5-aza-2'-deoxycytidine, zebularine, hydralazine, epigallocatechin gallate, and psammaplin A) for 18 hours prior to radiation, after which cell survival was evaluated via clonogenic assays. Cell cycle and apoptosis were analyzed via flow cytometry. Expressions of DNMT1, 3A/3B, and cleaved caspase-3 were detected via Western blotting. Expression of γH2AX, a marker of radiation-induced DNA double-strand break, was examined by immunocytochemistry. Pretreatment with psammaplin A, 5-aza-2'-deoxycytidine, and zebularine radiosensitized both A549 and U373MG cells. Pretreatment with psammaplin A increased the sub-G1 fraction of A549 cells, as compared to cells exposed to radiation alone. Prolongation of γH2AX expression was observed in the cells treated with DNMT inhibitors prior to radiation as compared with those treated by radiation alone. Psammaplin A, 5-aza-2'-deoxycytidine, and zebularine induce radiosensitivity in both A549 and U373MG cell lines, and suggest that this effect might be associated with the inhibition of DNA repair

  18. Radiosensitizing efficacy of iso-metronidazole after intravesical application in bladder cancer. A clinical phase II study

    International Nuclear Information System (INIS)

    Kob, D.; Lilienthal, A.; Bauhardt, H.; Merkle, K.; Schroeder, E.; Schroeder, E.; Hentschel, M.

    1991-01-01

    The radiosensitizing efficacy of iso-Metronidazole, a 4-Nitroimidazole derivative, was evaluated in a prospective clinical phase II study. The results of combined radiotherapy of 25 patients with bladder cancer were compared with those of a control group of 25 patients treated with radiotherapy only. Tumor regression six months after radiotherapy was used as an endpoint. The surgical procedure was performed as double TUR. Evaluating the local tumor control after additional application of iso-Metronidazole a gain factor of 1.2 is obtained. (orig.) [de

  19. Radiosensitization of pancreatic cancer cells by 2',2'-difluoro-2'-deoxycytidine

    International Nuclear Information System (INIS)

    Lawrence, Theodore S.; Chang, Emily Y.; Hahn, Tina M.; Hertel, Larry W.; Shewach, Donna S.

    1996-01-01

    Purpose: We have reported that the deoxycytidine analog 2',2'-difluoro-2'-deoxycytidine (dFdCyd) is a potent radiosensitizer of HT29 human colon cancer cells probably through its effects on intracellular deoxyribonucleotide (dNTP) pools. Because dFdCyd has activity against pancreatic cancer in clinical trials, we wished to determine if dFdCyd would radiosensitize human pancreatic cancer cells. Methods and Materials: We assessed the effect of dFdCyd on radiation sensitivity of two human pancreatic cancer cell lines, Panc-1 and BxPC-3. To begin to investigate the mechanism of sensitization, we determined the effect of dFdCyd on dNTP pools and cell cycle distribution. Results: We found that dFdCyd produced radiation enhancement ratios of 1.7-1.8 under noncytotoxic conditions in both cell lines. Sensitization was not associated with intracellular levels of 2',2'-difluoro-2'-deoxycytidine triphosphate, the cytotoxic metabolite of dFdCyd, but occurred when dATP pools were depleted below the level of approximately 1 μM. Although both cell lines showed substantial cell cycle redistribution after drug treatment, the flow cytogram of the BxPC-3 cells would not, by itself, be anticipated to result in increased radiation sensitivity. Conclusions: These findings demonstrate that dFdCyd is a potent radiation sensitizer of human pancreatic cancer cells and support the development of a clinical protocol using combined dFdCyd and radiation therapy in the treatment of pancreatic cancer

  20. Enhanced Radiosensitization Effect of Curcumin Delivered by PVP-PCL Nanoparticle in Lung Cancer

    Directory of Open Access Journals (Sweden)

    Cuixia Wen

    2017-01-01

    Full Text Available Curcumin, the principal polyphenolic curcuminoid, has been reported in numerous studies for its antitumor effect in a series of cancers. It is also reported that curcumin possesses radiosensitization effect in some cancers. However, the poor solubility and unsatisfied bioavailability of curcumin significantly undermine its potential application. Here we prepared curcumin loaded nanoparticles by employing PVP-PCL as drug carrier. Characterization studies indicated the satisfied drug loading efficiency and a sustained in vitro release pattern. Quantification uptake study showed that the uptake efficiency of Cum-NPs by lung cancer cells was time- and dose-dependent. In vitro anticancer study demonstrated the superior cytotoxic effect of Cum-NPs with stronger apoptotic induction over free Cum. Most importantly, there is almost no report on the radiosensitization effect of curcumin loaded nanoparticles. Here, Cum-NPs led to more inhibition of the colony forming ability of A549 cells as compared to the equivalent concentration of free Cum as shown in clonogenic assay. Furthermore, Cum-NPs are much more effective in enhancing the tumor growth inhibitory effect of radiation therapy in a A549 xenograft model. Therefore, results from the current study seem to be the first report on the radiosensitization effect of Cum-NPs and paved the way for a curcumin nanodrug delivery system as a potential radiation adjuvant.

  1. In vitro radiosensitization by oxaliplatin and 5-fluorouracil in a human colon cancer cell line

    International Nuclear Information System (INIS)

    Kjellstroem, Johan; Kjellen, Elisabeth; Johnsson, Anders

    2005-01-01

    The current study was designed to compare the radiosensitizing effects of oxaliplatin and 5-fluorouracil (5FU) in a human colon cancer cell line. A human colon cancer cell line (S1) was treated with various doses of oxaliplatin, 5FU, radiation, and combinations thereof. Various clinically used schedules were mimicked. 5FU was either incubated during 1 h ('bolus') or 24 h ('continuous infusion'). When combining oxaliplatin and 5FU, an isobologram analysis revealed synergistic effects, regardless of 5FU schedule. The IC 10 and IC 50 -doses for the drugs where then combined with radiotherapy. With equitoxic drug doses (IC 50 ), radiosensitization was observed in the following order: oxaliplatin>5FU 24 h>5FU 1 h exposure. The degree of potentiation corresponded to approximately 0.8 Gy, 0.7 Gy, and 0.2 Gy, respectively. In this experimental setting, oxaliplatin seemed to be a better radiosensitizer than 5FU, and longer incubation time with 5FU was better than short exposure

  2. TGFβ1 polymorphisms and late clinical radiosensitivity in patients treated for gynecologic tumors

    International Nuclear Information System (INIS)

    Ruyck, Kim de; Van Eijkeren, Marc; Claes, Kathleen; Bacher, Klaus; Vral, Anne; Neve, Wilfried de; Thierens, Hubert

    2006-01-01

    Purpose: To investigate the association between six transforming growth factor β1 gene (TGFβ1) polymorphisms (-1.552delAGG, -800G>A, -509C>T, Leu10Pro, Arg25Pro, Thr263Ile) and the occurrence of late normal tissue reactions after gynecologic radiotherapy (RT). Methods and Materials: Seventy-eight women with cervical or endometrial cancer and 140 control individuals were included in the study. According to the Common Terminology Criteria for Adverse Events version 3.0 (CTCAEv3.0) scale, 25 patients showed late adverse RT reactions (CTC2+), of whom 11 had severe complications (CTC3+). Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), single base extension and genotyping assays were performed to examine the polymorphic sites in TGFβ1. Results: Homozygous variant -1.552delAGG, -509TT, and 10Pro genotypes were associated with the risk of developing late severe RT reactions. Triple (variant) homozygous patients had a 3.6 times increased risk to develop severe RT reactions (p = 0.26). Neither the -800A allele, nor the 25Pro allele or the 263Ile allele were associated with clinical radiosensitivity. There was perfect linkage disequilibrium (LD) between the -1.552delAGG and the -509C>T polymorphisms, and tight LD between the -1.552/-509 and the Leu10Pro polymorphisms. Haplotype analysis revealed two major haplotypes but could not distinguish radiosensitive from nonradiosensitive patients. Conclusions: The present study shows that homozygous variant TGFβ1 -1.552delAGG, -509TT, and 10Pro genotypes may be associated with severe clinical radiosensitivity after gynecologic RT

  3. Preclinical evaluation of sunitinib, a multi-tyrosine kinase inhibitor, as a radiosensitizer for human prostate cancer

    International Nuclear Information System (INIS)

    Brooks, Colin; Sheu, Tommy; Bridges, Kathleen; Mason, Kathy; Kuban, Deborah; Mathew, Paul; Meyn, Raymond

    2012-01-01

    Many prostate cancers demonstrate an increased expression of growth factor receptors such as vascular endothelial growth factor receptor (VEGFR) and platelet derived growth factor receptor (PDGFR) which have been correlated with increased resistance to radiotherapy and poor prognosis in other tumors. Therefore, response to radiation could potentially be improved by using inhibitors of these abnormally activated pathways. We have investigated the radiosensitizing effects of sunitinib, a potent, multi-tyrosine kinase inhibitor of the VEGFR and PDGFR receptors, on human prostate cancer cells. The radiosensitizing effects of sunitinib were assessed on human prostate cancer cell lines DU145, PC3 and LNCaP by clonogenic assay. Sunitinib’s ability to inhibit the activities of its key targets was determined by immunoblot analysis. The radiosensitizing effects of sunitinib in vivo were tested on human tumor xenografts growing in nude mice where response was assessed by tumor growth delay. Clonogenic survival curve assays for both DU145 and PC3 cells showed that the surviving fraction at 2 Gy was reduced from 0.70 and 0.52 in controls to 0.44 and 0.38, respectively, by a 24 hr pretreatment with 100 nM sunitinib. LNCaP cells were not radiosensitized by sunitinib. Dose dependent decreases in VEGFR and PDGFR activation were also observed following sunitinib in both DU145 and PC3 cells. We assessed the ability of sunitinib to radiosensitize PC3 xenograft tumors growing in the hind limb of nude mice. Sunitinib given concurrently with radiation did not prolong tumor growth delay. However, when animals were treated with sunitinib commencing the day after fractionated radiation was complete, tumor growth delay was enhanced compared to radiation alone. We conclude, based on the in vivo results, that sunitinib and radiation do not interact directly to radiosensitize the PC3 tumor cells in vivo as they did in vitro. The fact that tumor growth delay was enhanced when sunitinib was

  4. Non-surgical breast-conservation treatment (KORTUC-BCT) using a new image-guided, enzyme-targeted, and breast cancer stem cell targeted radiosensitization treatment (KORTUC II) for patients with stage I or II breast cancer

    International Nuclear Information System (INIS)

    Ogawa, Yasuhiro; Kubota, Kei; Tadokoro, Michiko

    2012-01-01

    Tumor tissue can be re-oxygenated by inactivating peroxidase/catalase in the tumor tissue through application of hydrogen peroxide. The hydrogen peroxide in turn is then degraded to produce oxygen. In this way, low-LET (linear energy transfer) radioresistant tumors can be transformed into radiosensitive ones (Ogawa Y, et al: Int J Mol Med 12: 453-458, 845-850, 2003, Ogawa Y, et al: Int J Mol Med 14: 397-403, 2004, Kariya S, et al: Int J Radiat Oncol Biol Phys 75: 449-454, 2009). The purpose of the present study was to establish a non-surgical breast-conservation treatment (KORTUC-BCT) by utilizing a novel Kochi Oxydol-Radiation Therapy for Unresectable Carcinomas, Type II (KORTUC II) radiosensitization treatment. KORTUC I was shown to remarkably enhance radiotherapeutic effects in various types of superficially exposed and locally advanced neoplasms (Ogawa Y, et al: Oncol Rep 19: 1389-1394, 2008). Based on clinical experiences using KORTUC I, a new radiosensitizing agent containing hydrogen peroxide and sodium hyaluronate has been developed for intra-tumoral injection in various tumors which are not superficially exposed. The agent is composed of 0.5% hydrogen peroxide and 0.83% sodium hyaluronate (CD44 molecule). Sodium hyaluronate mixed with hydrogen peroxide attaches to CD44-positive tumor cells, which are generally reported to be breast cancer stem cells. This new method, named KORTUC II, was approved by our local ethics committee for treatment of advanced skin cancer (including malignant melanoma), bone/soft tissue malignant neoplasm, breast cancer and metastatic lymph node. A total of 39 early stage breast cancer patients (stage I: 12 patients and stage II: 27) were enrolled in the KORTUC II trial upon fully informed consent. Mean age of the patients was 61.1 years old. All 39 patients were unable or unwilling to undergo surgery and therefore undertook non-surgical breast-conservation treatment (KORTUC-BCT) by KORTUC II. A maximum of 6 ml of the agent was

  5. Leukocyte apoptosis as a predictor of radiosensitivity in Fanconi anemia

    International Nuclear Information System (INIS)

    Petrovic, Sandra; Leskovac, Andreja; Joksic, Ivana; Filipovic, Jelena; Joksic, Gordana; Vujic, Dragana; Guc-Scekic, Marija

    2013-01-01

    Fanconi anemia (FA) is a rare cancer-prone genetic disease characterized by impaired oxygen metabolism and defects in DNA damage repair. Response of FA cells to ionizing radiation has been an issue intensively debated in the literature. To study in vitro radiosensitivity in patients suffering from FA and their parents (heterozygous carriers), we determined radiation-induced leukocyte apoptosis using flow cytometry. As TP53 gene is involved in the control of apoptosis, we studied its status in FA lymphocytes using dual colour fluorescence in situ hybridization (FISH). FA patients and female heterozygous carriers display radiosensitive response to ionizing radiation seen as abnormal elimination of cells via apoptosis. By employment of FISH, the TP53 allele loss in FA lymphocytes was not observed. In diseases related to oxidative stress, determination of radiation-induced apoptosis is the method of choice for testing the radiosensitivity. (author)

  6. Apoptosis in peripheral blood lymphocytes of healthy donors and patients with laryngeal cancer after γ-irradiation in vitro

    International Nuclear Information System (INIS)

    Orlova, N.V.; Smirnova, S.G.; Zamulaeva, I.A.; Andreev, V.G.; Ryabchenko, N.I.; Saenko, A.S.

    2001-01-01

    Apoptosis in peripheral blood lymphocytes of healthy donors and cancer patients after γ-radiation with different doses is studied by the flow cytometry method. Wide intra- and interindividual variabilities of the lymphocyte radiosensitivity by different donors are observed. The radiosensitivity does not depend on the subpopulation composition of the lymphocyte pool. The persons with very low and high lymphocyte radiosensitivities are found significantly more often among the cancer patients than among the healthy donors. One can suggest that this method is useful to define risk groups with regard to radiogenic neoplasms and prognosis of radiotherapy efficiency [ru

  7. Pronounced radiosensitization of cultured human cancer cells by COX inhibitor under acidic microenvironment

    International Nuclear Information System (INIS)

    Shah, Tushar; Ryu, Samuel; Lee, Ho Jun; Brown, Stephen; Kim, Jae Ho

    2002-01-01

    Purpose: To demonstrate the influence of pH on the cytotoxicity and radiosensitization by COX (cyclooxygenase) -1 and -2 inhibitors using established human cancer cells in culture. Methods and Materials: Nonselective COX inhibitor, ibuprofen (IB), and selective COX-2 inhibitor, SC-236, were used to determine the cytotoxicity and radiosensitization at varying pH of culture media. Human colon carcinoma cell line (HT-29) was exposed to the drug alone and in combination with radiation at different pH of the cell culture media. The end point was clonogenic ability of the single-plated cells after the treatment. Results: Cytotoxicity and radiosensitization of IB increased with higher drug concentration and longer exposure time. The most significant radiosensitization was seen with IB (1.5 mM) for 2-h treatment at pH 6.7 before irradiation. The dose-modifying factor as defined by the ratio of radiation doses required to achieve the same effect on cell survival was 1.8 at 10% survival level. In contrast, SC-236 (50 μM for 2-8 h) showed no pH-dependent cytotoxicity. There was modest increase in the cell killing at lower doses of radiation. Conclusion: An acidic pH was an important factor affecting the increased cytotoxicity and radiosensitization by ibuprofen. Radiation response was enhanced at shoulder portion of the cell survival curve by selective COX-2 inhibitor

  8. Radiosensitivity of cells

    International Nuclear Information System (INIS)

    Alexander, P.

    1960-01-01

    The mechanism by which radiation kills cells must be investigated with the goal to make possible to devise means to alter the radiosensitivity of cells. The object of our investigation, supported by IAEA, is to try and find the reasons for the variation in sensitivity between different cells. Once we know the reason for the differences in radiosensitivity of different micro-organisms we can begin to look rationally for ways of enhancing the radiation response of the more sensitive organisms. An investigation of this type has implications far beyond food sterilization, as it cannot fail to provide fundamental facts about radiation injury to cells in general. Cancer researchers have looked for many years for means of sensitizing cancer cells to radiation

  9. Radiosensitivity of cells

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, P [Radiation Biology Section, Chester Beatty Research Institute, Royal Cancer Hospital, London (United Kingdom)

    1960-07-15

    The mechanism by which radiation kills cells must be investigated with the goal to make possible to devise means to alter the radiosensitivity of cells. The object of our investigation, supported by IAEA, is to try and find the reasons for the variation in sensitivity between different cells. Once we know the reason for the differences in radiosensitivity of different micro-organisms we can begin to look rationally for ways of enhancing the radiation response of the more sensitive organisms. An investigation of this type has implications far beyond food sterilization, as it cannot fail to provide fundamental facts about radiation injury to cells in general. Cancer researchers have looked for many years for means of sensitizing cancer cells to radiation

  10. Radiation response in vitro of fibroblasts from a Fanconi anemia patient with marked clinical radiosensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Djuzenova, C.; Flentje, M. [Dept. of Radiotherapy, Univ. of Wuerzburg, Wuerzburg (Germany); Plowman, P.N. [Radiotherapy/Clinical Oncology, St. Bartholomew' s Hospital, London (United Kingdom)

    2004-12-01

    Background: fanconi anemia (FA) is an autosomal recessive chromosome instability disorder characterized by progressive pancytopenia and cancer susceptibility. The risks of radiation therapy in FA patients who have cancer remain to be investigated. Recently, Marcou et al. (2001) reported a case of severe clinical radiosensitivity in a female FA patient with a tonsillar squamous cell carcinoma treated by radiotherapy. By contrast, her in vitro irradiated skin fibroblasts revealed nearly normal radiosensitivity as determined by the colony survival assay. Material and methods: in view of this discrepancy, the radiation response of this particular FA fibroblast strain (designated 425BR) was further analyzed in the present study by means of the alkaline single-cell gel electrophoresis (Comet) assay, and also by the cytochalasin-blocked micronuclei (MN) test. In addition, the expression levels of DNA repair proteins, hMre11, Rad50, and Rad51, were investigated using Western blot and foci immunofluorescence staining. Results: the Comet assay revealed that the initial DNA fragmentation in irradiated FA cells was two times higher and the DNA rejoining process was three times slower than that in control (1BR3) fibroblasts. Moreover, although the baseline level of MNs was lower in FA cells than in controls, the FA fibroblasts were more prone (about two times) to MN production than control cells when irradiated with 2-4 Gy. Western blot analysis of the DNA repair proteins (hMre11, Rad50, and Rad51) did not reveal any abnormalities in protein expression levels or their migration patterns in the fibroblasts derived from an FA patient either before or after irradiation. At the same time, in vitro irradiated cells from the FA patient exhibited a significantly reduced number of nuclei with focally concentrated DNA repair Rad51 protein than in control cells. Conclusion: the increased DNA damage and MN induction in irradiated FA fibroblasts, and the reduction of the formation of DNA

  11. Radiation response in vitro of fibroblasts from a Fanconi anemia patient with marked clinical radiosensitivity

    International Nuclear Information System (INIS)

    Djuzenova, C.; Flentje, M.; Plowman, P.N.

    2004-01-01

    Background: fanconi anemia (FA) is an autosomal recessive chromosome instability disorder characterized by progressive pancytopenia and cancer susceptibility. The risks of radiation therapy in FA patients who have cancer remain to be investigated. Recently, Marcou et al. (2001) reported a case of severe clinical radiosensitivity in a female FA patient with a tonsillar squamous cell carcinoma treated by radiotherapy. By contrast, her in vitro irradiated skin fibroblasts revealed nearly normal radiosensitivity as determined by the colony survival assay. Material and methods: in view of this discrepancy, the radiation response of this particular FA fibroblast strain (designated 425BR) was further analyzed in the present study by means of the alkaline single-cell gel electrophoresis (Comet) assay, and also by the cytochalasin-blocked micronuclei (MN) test. In addition, the expression levels of DNA repair proteins, hMre11, Rad50, and Rad51, were investigated using Western blot and foci immunofluorescence staining. Results: the Comet assay revealed that the initial DNA fragmentation in irradiated FA cells was two times higher and the DNA rejoining process was three times slower than that in control (1BR3) fibroblasts. Moreover, although the baseline level of MNs was lower in FA cells than in controls, the FA fibroblasts were more prone (about two times) to MN production than control cells when irradiated with 2-4 Gy. Western blot analysis of the DNA repair proteins (hMre11, Rad50, and Rad51) did not reveal any abnormalities in protein expression levels or their migration patterns in the fibroblasts derived from an FA patient either before or after irradiation. At the same time, in vitro irradiated cells from the FA patient exhibited a significantly reduced number of nuclei with focally concentrated DNA repair Rad51 protein than in control cells. Conclusion: the increased DNA damage and MN induction in irradiated FA fibroblasts, and the reduction of the formation of DNA

  12. The combination effect of sodium butyrate and 5-Aza-2'-deoxycytidine on radiosensitivity in RKO colorectal cancer and MCF-7 breast cancer cell lines

    Directory of Open Access Journals (Sweden)

    Oh Seong

    2009-05-01

    Full Text Available Abstract Background The overall level of chromatin compaction is an important mechanism of radiosensitivity, and modification of DNA methylation and histone deacetylation may increase radiosensitivity by altering chromatin compaction. In this study, we investigated the effect of a demethylating agent, a histone deacetylase(HDAC inhibitor, and the two agents combined on radiosensitivity in human colon and breast cancer cell lines. Methods In this study, we used RKO colorectal cancer cell line and MCF-7 breast cancer cell lines and normal colon cell lines. On each of the cell lines, we used three different agents: the HDAC inhibitor sodium butyrate(SB, the demethylating agent 5-Aza-2'-deoxycytidine(5-aza-DC, and radiation. We then estimated the percentage of the cell survival using the XTT method and experimented to determine if there was an augmentation in the therapeutic effect by using different combinations of the two or three of the treatment methods. Results After treatment of each cell lines with 5-aza-DC, SB and 6 grays of radiation, we observed that the survival fraction was lower after the treatment with 5-aza-DC or SB than with radiation alone in RKO and MCF-7 cell lines(p Conclusion In conclusion, 5-aza-DC and SB can enhance radiosensitivity in both MCF-7 and RKO cell lines. The combination effect of a demethylating agent and an HDAC inhibitor is more effective than that of single agent treatment in both breast and colon cancer cell lines.

  13. Radiosensitizers action on Iodine 131 therapeutical effect

    International Nuclear Information System (INIS)

    Agote, Marcos; Kreimann, Erica L.; Bocanera, Laura V.; Dagrosa, Maria A.; Juvenal, Guillermo J.; Pisarev, Mario A.

    1999-01-01

    Present studies were aimed to research the possible application of a radiosensitizer, nicotinamide, to increase the therapeutical effect of radioiodine. There were used goitrous and normal rats with growing dose of Iodine 131, with and without simultaneous treatment with nicotinamide. The obtained results show that the nicotinamide treatment importantly increases the thyroid radio destructive effect induced by radioiodine. Under these experimental conditions, nicotinamide induces to a significant increase of thyroid vascularisation, without changes in the proteins ADP-ribosylation activity. These results show, for the first time, the radiosensitizer effect of nicotinamide in front of Iodine 131 and give the possibility of using it in the treatment of hyperthyroid or thyroid difference cancer patients. (author)

  14. Cisplatin-mediated radiosensitization of non-small cell lung cancer cells is stimulated by ATM inhibition

    International Nuclear Information System (INIS)

    Toulany, Mahmoud; Mihatsch, Julia; Holler, Marina; Chaachouay, Hassan; Rodemann, H. Peter

    2014-01-01

    Background and purpose: Cisplatin activates ataxia-telangiectasia-mutated (ATM), a protein with roles in DNA repair, cell cycle progression and autophagy. We investigated the radiosensitizing effect of cisplatin with respect to its effect on ATM pathway activation. Material and methods: Non-small cell lung cancer cells (NSCLC) cell lines (A549, H460) and human fibroblast (ATM-deficient AT5, ATM-proficient 1BR3) cells were used. The effects of cisplatin combined with irradiation on ATM pathway activity, clonogenicity, DNA double-strand break (DNA-DSB) repair and cell cycle progression were analyzed with Western blotting, colony formation and γ-H2AX foci assays as well as FACS analysis, respectively. Results: Cisplatin radiosensitized H460 cells, but not A549 cells. Radiosensitization of H460 cells was not due to impaired DNA-DSB repair, increased apoptosis or cell cycle dysregulation. The lack of radiosensitization demonstrated for A549 cells was associated with cisplatin-mediated stimulation of ATM (S1981) and AMPKα (T172) phosphorylation and autophagy. However, in both cell lines inhibition of ATM and autophagy by KU-55933 and chloroquine diphosphate (CQ) respectively resulted in a significant radiosensitization. Combined treatment with the AMPK inhibitor compound-C led to radiosensitization of A549 but not of H460 cells. As compared to the treatment with KU-55933 alone, radiosensitivity of A549 cells was markedly stimulated by the combination of KU-55933 and cisplatin. However, the combination of CQ and cisplatin did not modulate the pattern of radiation sensitivity of A549 or H460 cells. In accordance with the results that cisplatin via stimulation of ATM activity can abrogate its radiosensitizing effect, ATM deficient cells were significantly sensitized to ionizing radiation by cisplatin. Conclusion: The results obtained indicate that ATM targeting can potentiate cisplatin-induced radiosensitization

  15. Targeting MEK5 Enhances Radiosensitivity of Human Prostate Cancer and Impairs Tumor-Associated Angiogenesis

    Science.gov (United States)

    2016-09-01

    analysis of tumor necrosis factor - alpha resistant human breast cancer cells reveals a MEK5/Erk5-mediated epithelial-mesenchymal transition phenotype...AWARD NUMBER: W81XWH-15-1-0296 TITLE: Targeting MEK5 Enhances Radiosensitivity of Human Prostate Cancer and Impairs Tumor - Associated...Cancer and Impairs Tumor -Associated Angiogenesis 5b. GRANT NUMBER W81XWH-15-1-0296 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER

  16. Radiosensitization of head and neck cancer cells by the phytochemical agent sulforaphane

    International Nuclear Information System (INIS)

    Kotowski, Ulana; Heiduschka, Gregor; Brunner, Markus; Fahim, Tammer; Thurnher, Dietmar; Czembirek, Cornelia; Eder-Czembirek, Christina; Schmidt, Rainer

    2011-01-01

    Sulforaphane is a naturally occurring compound found in broccoli and other cruciferous vegetables. Recently it gained attention because of its antiproliferative properties in many cancer cell lines. The aim of this study was to investigate whether sulforaphane could act as a radiosensitizer in head and neck squamous cell carcinoma cell lines. Four head and neck squamous cell carcinoma cell lines (i.e., (HNSCC) SCC9, SCC25, CAL27, and FADU) were treated with sulforaphane and subsequently irradiated. Then proliferation and clonogenic assays were performed. Apoptosis was detected by flow cytometry. Possible regulation of Akt and Mcl-1 was investigated by western blotting. Sulforaphane and radiation in combination leads to stronger inhibition of cell proliferation and of clonogenic survival than each treatment method alone. Western blot analysis of Akt and Mcl-1 showed no changed expression. Sulforaphane is a promising agent in the treatment of head and neck cancer due to its antiproliferative and radio-sensitizing properties. A combination of sulforaphane and radiation decreases clonogenic survival. Apoptosis is not regulated through Akt or the Mcl-1 protein. (orig.)

  17. Radiosensitization of head and neck cancer cells by the phytochemical agent sulforaphane

    Energy Technology Data Exchange (ETDEWEB)

    Kotowski, Ulana; Heiduschka, Gregor; Brunner, Markus; Fahim, Tammer; Thurnher, Dietmar [Medical University of Vienna (Austria). Dept. of Otorhinolaryngology, Head and Neck Surgery; Czembirek, Cornelia; Eder-Czembirek, Christina [Medical University of Vienna (Austria). Dept. of Cranio-, Maxillofacial and Oral Surgery; Schmidt, Rainer [Medical University of Vienna (Austria). Dept. of Radiotherapy and -biology

    2011-09-15

    Sulforaphane is a naturally occurring compound found in broccoli and other cruciferous vegetables. Recently it gained attention because of its antiproliferative properties in many cancer cell lines. The aim of this study was to investigate whether sulforaphane could act as a radiosensitizer in head and neck squamous cell carcinoma cell lines. Four head and neck squamous cell carcinoma cell lines (i.e., (HNSCC) SCC9, SCC25, CAL27, and FADU) were treated with sulforaphane and subsequently irradiated. Then proliferation and clonogenic assays were performed. Apoptosis was detected by flow cytometry. Possible regulation of Akt and Mcl-1 was investigated by western blotting. Sulforaphane and radiation in combination leads to stronger inhibition of cell proliferation and of clonogenic survival than each treatment method alone. Western blot analysis of Akt and Mcl-1 showed no changed expression. Sulforaphane is a promising agent in the treatment of head and neck cancer due to its antiproliferative and radio-sensitizing properties. A combination of sulforaphane and radiation decreases clonogenic survival. Apoptosis is not regulated through Akt or the Mcl-1 protein. (orig.)

  18. Prostate-Specific Natural Health Products (Dietary Supplements) Radiosensitize Normal Prostate Cells

    International Nuclear Information System (INIS)

    Hasan, Yasmin; Schoenherr, Diane; Martinez, Alvaro A.; Wilson, George D.; Marples, Brian

    2010-01-01

    Purpose: Prostate-specific health products (dietary supplements) are taken by cancer patients to alleviate the symptoms linked with poor prostate health. However, the effect of these agents on evidence-based radiotherapy practice is poorly understood. The present study aimed to determine whether dietary supplements radiosensitized normal prostate or prostate cancer cell lines. Methods and Materials: Three well-known prostate-specific dietary supplements were purchased from commercial sources available to patients (Trinovin, Provelex, and Prostate Rx). The cells used in the study included normal prostate lines (RWPE-1 and PWR-1E), prostate tumor lines (PC3, DU145, and LNCaP), and a normal nonprostate line (HaCaT). Supplement toxicity was assessed using cell proliferation assays [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] and cellular radiosensitivity using conventional clonogenic assays (0.5-4Gy). Cell cycle kinetics were assessed using the bromodeoxyuridine/propidium iodide pulse-labeling technique, apoptosis by scoring caspase-3 activation, and DNA repair by assessing γH2AX. Results: The cell growth and radiosensitivity of the malignant PC3, DU145, and LNcaP cells were not affected by any of the dietary prostate supplements (Provelex [2μg/mL], Trinovin [10μg/mL], and Prostate Rx [50 μg/mL]). However, both Trinovin (10μg/mL) and Prostate Rx (6μg/mL) inhibited the growth rate of the normal prostate cell lines. Prostate Rx increased cellular radiosensitivity of RWPE-1 cells through the inhibition of DNA repair. Conclusion: The use of prostate-specific dietary supplements should be discouraged during radiotherapy owing to the preferential radiosensitization of normal prostate cells.

  19. Radiosensitizing effect of PSMC5, a 19S proteasome ATPase, in H460 lung cancer cells

    International Nuclear Information System (INIS)

    Yim, Ji-Hye; Yun, Hong Shik; Lee, Su-Jae; Baek, Jeong-Hwa; Lee, Chang-Woo; Song, Ji-Young; Um, Hong-Duck; Park, Jong Kuk; Kim, Jae-Sung; Park, In-Chul; Hwang, Sang-Gu

    2016-01-01

    The function of PSMC5 (proteasome 26S subunit, ATPase 5) in tumors, particularly with respect to cancer radioresistance, is not known. Here, we identified PSMC5 as a novel radiosensitivity biomarker, demonstrating that radiosensitive H460 cells were converted to a radioresistance phenotype by PSMC5 depletion. Exposure of H460 cells to radiation induced a marked accumulation of cell death-promoting reactive oxygen species, but this effect was blocked in radiation-treated H460 PSMC5-knockdown cells through downregulation of the p53-p21 pathway. Interestingly, PSMC5 depletion in H460 cells enhanced both AKT activation and MDM2 transcription, thereby promoting the degradation of p53 and p21 proteins. Furthermore, specific inhibition of AKT with triciribine or knockdown of MDM2 with small interfering RNA largely restored p21 expression in PSMC5-knockdown H460 cells. Our data suggest that PSMC5 facilitates the damaging effects of radiation in radiation-responsive H460 cancer cells and therefore may serve as a prognostic indicator for radiotherapy and molecular targeted therapy in lung cancer patients. - Highlights: • PSMC5 is a radiation-sensitive biomarker in H460 cells. • PSMC5 depletion inhibits radiation-induced apoptosis in H460 cells. • PSMC5 knockdown blocks ROS generation through inhibition of the p53-p21 pathway. • PSMC5 knockdown enhances p21 degradation via AKT-dependent MDM2 stabilization.

  20. Nanoparticle Drones to Target Lung Cancer with Radiosensitizers and Cannabinoids.

    Science.gov (United States)

    Ngwa, Wilfred; Kumar, Rajiv; Moreau, Michele; Dabney, Raymond; Herman, Allen

    2017-01-01

    Nanotechnology has opened up a new, previously unimaginable world in cancer diagnosis and therapy, leading to the emergence of cancer nanomedicine and nanoparticle-aided radiotherapy. Smart nanomaterials (nanoparticle drones) can now be constructed with capability to precisely target cancer cells and be remotely activated with radiation to emit micrometer-range missile-like electrons to destroy the tumor cells. These nanoparticle drones can also be programmed to deliver therapeutic payloads to tumor sites to achieve optimal therapeutic efficacy. In this article, we examine the state-of-the-art and potential of nanoparticle drones in targeting lung cancer. Inhalation (INH) (air) versus traditional intravenous ("sea") routes of navigating physiological barriers using such drones is assessed. Results and analysis suggest that INH route may offer more promise for targeting tumor cells with radiosensitizers and cannabinoids from the perspective of maximizing damage to lung tumors cells while minimizing any collateral damage or side effects.

  1. Inhibition of HAS2 induction enhances the radiosensitivity of cancer cells via persistent DNA damage

    International Nuclear Information System (INIS)

    Shen, Yan Nan; Shin, Hyun-Jin; Joo, Hyun-Yoo; Park, Eun-Ran; Kim, Su-Hyeon; Hwang, Sang-Gu; Park, Sang Jun; Kim, Chun-Ho; Lee, Kee-Ho

    2014-01-01

    Highlights: •HAS2 may be a promising target for the radiosensitization of human cancer. •HAS2 is elevated (up to ∼10-fold) in irradiated radioresistant and -sensitive cancer cells. •HAS2 knockdown sensitizes cancer cells to radiation. •HAS2 knockdown potentiates irradiation-induced DNA damage and apoptotic death. •Thus, the irradiation-induced up-regulation of HAS2 contributes to the radioresistance of cancer cells. -- Abstract: Hyaluronan synthase 2 (HAS2), a synthetic enzyme for hyaluronan, regulates various aspects of cancer progression, including migration, invasion and angiogenesis. However, the possible association of HAS2 with the response of cancer cells to anticancer radiotherapy, has not yet been elucidated. Here, we show that HAS2 knockdown potentiates irradiation-induced DNA damage and apoptosis in cancer cells. Upon exposure to radiation, all of the tested human cancer cell lines exhibited marked (up to 10-fold) up-regulation of HAS2 within 24 h. Inhibition of HAS2 induction significantly reduced the survival of irradiated radioresistant and -sensitive cells. Interestingly, HAS2 depletion rendered the cells to sustain irradiation-induced DNA damage, thereby leading to an increase of apoptotic death. These findings indicate that HAS2 knockdown sensitizes cancer cells to radiation via persistent DNA damage, further suggesting that the irradiation-induced up-regulation of HAS2 contributes to the radioresistance of cancer cells. Thus, HAS2 could potentially be targeted for therapeutic interventions aimed at radiosensitizing cancer cells

  2. Exfoliative cytology in study of radiosensitivity of uterine cervical cancer, (2)

    International Nuclear Information System (INIS)

    Tsukahara, Yoshiharu; Noguchi, Hiroshi; Tomita, Kazuhiko; Kotani, Toshio; Nakayama, Akiko

    1977-01-01

    In this paper, we discuss the possibility of cytological judgment of radiosensitivity of uterine cervical cancer by comparison between pre- and post-irradiation smears given 1,000 rads by telecobalt external test irradiation. The estimation of radiation effects on nuclei and the cytological presumption of histological typing in pre-irradiation smears have brought about satisfactory results; agreement between histological and cytological judgements of radiosensitivity was about 96.8%. Cytological criteria of good sensitivity are as follows; Disparity in size of chromatin particles and irregular distribution. Irregularity of nuclear membrane with nuclear wrinkling with diminution of thickness of nuclear membrane. Mature squamous cell carcinoma without pearl formation. Those of poor sensitivity are as follows; Existence of many unchanged viable cells and less disturbances of chromatines. Existence of cells exibiting adenocarcinoma and carcinoma of intermediate type. Clusters of cyanophilic cells having lacy, indistinct cell borders. (auth.)

  3. Icotinib enhances lung cancer cell radiosensitivity in vitro and in vivo by inhibiting MAPK/ERK and AKT activation.

    Science.gov (United States)

    Fu, Yonghong; Zhang, Sen; Wang, Dongjie; Wang, Jing

    2018-05-16

    Icotinib hydrochloride is a small epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) that was developed by Chinese scientists. While clinical trials have revealed its efficacy in the treatment of lung cancer, very little is known about its role in enhancing radiosensitivity. In this study, we investigated the effectiveness of Icotinib in enhancing lung cancer cell radiosensitivity and have detailed its underlying molecular mechanism. The lung cancer cell line H1650 was pretreated with or without Icotinib for 24 hours before radiation, and clonogenic survival assay was performed. Cell apoptosis was also analyzed by flow cytometry, while western blotting was performed to examine the activation of EGFR and its downstream kinases in H1650 cells after Icotinib and radiation treatment. Furthermore, a xenograft animal model was established to evaluate the radiosensitivity of Icotinib in vivo and to confirm its mechanism. Our results demonstrate that pretreatment with Icotinib reduced clonogenic survival after radiation, inhibited EGFR activation, and increased radiation-induced apoptosis in H1650 cells. The phosphorylation of protein kinase B (AKT), extracellular regulated protein kinase 1/2 (ERK1/2), and EGFR was inhibited after Icotinib and radiation combination treatment in vitro and in vivo compared with individual treatments. Combination treatment also affected the expression of the DNA repair protein H2A histone family member X (γ-H2AX). In conclusion, our results reveal that Icotinib enhances radiosensitivity in lung cancers in vitro and in vivo and the mechanism of this may involve blocking the EGFR-AKT and MAPK-ERK pathways and limiting DNA repair. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  4. Radiosensitivity in ataxia-telangiectasia

    International Nuclear Information System (INIS)

    Lavin, M.F.; Khanna, K.K.; Watters, D.

    1998-01-01

    Full text: Radiosensitivity is a major hallmark of the human genetic disorder ataxia-telangiectasia. This hypersensitivity to ionizing radiation has been demonstrated in vitro after exposure of patients to therapeutic thought to be the major factor contculture. Clearly an understanding of the nature of the molecular defect in ataxia-telangiectasia will be of considerable assistance in delineating additional pathways that determine cellular radiosensitivity/radioresistance. Furthermore, since patients with this syndrome are also predisposed to developing a number of leukaemias and lymphomas the possible connection between radiosensitivity and cancer predisposition is of interest. Now that the gene (ATM) responsible for this genetic disease has been cloned and identified, progress is being made in determining the role of the ATM protein in mediating the effects of cellular exposure to ionizing radiation and other forms of redox stress. Proteins such as the product of the tumour suppressor gene p53 and the proto-oncogene c-Abl (a protein tyrosine kinase) have been shown to interact with ATM. Since several intermediate steps in both the p53 and c-Abl pathways, activated by ionizing radiation, are known it will be possible to map the position of ATM in these pathways and describe its mechanism of action. What are the clinical implications of understanding the molecular basis of the defect in ataxia-telangiectasia? As outlined above since radiosensitivity is a universal characteristic of A-T understanding the mechanism of action of ATM will provide additional information or radiation signalling in human cells. With this information it may be possible to sensitize tumour cells to radiation and thus increase the therapeutic benefit of radiotherapy. This might involve the use of small molecules that would interfere with the normal ATM controlled pathways and thus sensitize cells to radiation or alternatively it might involve the efficient introduction of ATM anti-sense c

  5. Radiosensitivity in ataxia-telangiectasia

    Energy Technology Data Exchange (ETDEWEB)

    Lavin, M.F. [Royal Brisbane Hospital, QLD (Australia). Queensland Institute of Medical Research and The Department of Surgery; Khanna, K.K.; Watters, D. [Royal Brisbane Hospital, QLD (Australia). Queensland Institute of Medical Research

    1998-12-31

    Full text: Radiosensitivity is a major hallmark of the human genetic disorder ataxia-telangiectasia. This hypersensitivity to ionizing radiation has been demonstrated in vitro after exposure of patients to therapeutic thought to be the major factor contculture. Clearly an understanding of the nature of the molecular defect in ataxia-telangiectasia will be of considerable assistance in delineating additional pathways that determine cellular radiosensitivity/radioresistance. Furthermore, since patients with this syndrome are also predisposed to developing a number of leukaemias and lymphomas the possible connection between radiosensitivity and cancer predisposition is of interest. Now that the gene (ATM) responsible for this genetic disease has been cloned and identified, progress is being made in determining the role of the ATM protein in mediating the effects of cellular exposure to ionizing radiation and other forms of redox stress. Proteins such as the product of the tumour suppressor gene p53 and the proto-oncogene c-Abl (a protein tyrosine kinase) have been shown to interact with ATM. Since several intermediate steps in both the p53 and c-Abl pathways, activated by ionizing radiation, are known it will be possible to map the position of ATM in these pathways and describe its mechanism of action. What are the clinical implications of understanding the molecular basis of the defect in ataxia-telangiectasia? As outlined above since radiosensitivity is a universal characteristic of A-T understanding the mechanism of action of ATM will provide additional information or radiation signalling in human cells. With this information it may be possible to sensitize tumour cells to radiation and thus increase the therapeutic benefit of radiotherapy. This might involve the use of small molecules that would interfere with the normal ATM controlled pathways and thus sensitize cells to radiation or alternatively it might involve the efficient introduction of ATM anti-sense c

  6. Potential in a single cancer cell to produce heterogeneous morphology, radiosensitivity and gene expression

    International Nuclear Information System (INIS)

    Ban, Sadayuki; Ishikawa, Ken-ichi; Kawai, Seiko; Koyama-Saegusa, Kumiko; Ishikawa, Atsuko; Imai, Takashi; Shimada, Yutaka; Inazawa, Johji

    2005-01-01

    Morphologically heterogeneous colonies were formed from a cultured cell line (KYSE70) established from one human esophageal carcinoma tissue. Two subclones were separated from a single clone (clone 13) of KYSE70 cells. One subclone (clone 13-3G) formed mainly mounding colonies and the other (clone 13-6G) formed flat, diffusive colonies. X-irradiation stimulated the cells to dedifferentiate from the mounding state to the flat, diffusive state. Clone 13-6G cells were more radiosensitive than the other 3 cell lines. Clustering analysis for gene expression level by oligonucleotide microarray demonstrated that in the radiosensitive clone 13-6G cells, expression of genes involved in cell adhesion was upregulated, but genes involved in the response to DNA damage stimulus were downregulated. The data demonstrated that a single cancer cell had the potential to produce progeny heterogeneous in terms of morphology, radiation sensitivity and gene expression, and irradiation enhanced the dedifferentiation of cancer cells. (author)

  7. Diagnosis and therapy of cutaneous radiation syndrome. Individual radiosensitivity assessment in patients undergoing medical exposures presenting severe cutaneous radiation induced lesions

    International Nuclear Information System (INIS)

    Di Giorgio, Marina; Vallerga, Maria B.; Perez, Maria R.; Portas, Mercedes

    2007-01-01

    Hospital de Quemados del Gobierno de la Ciudad de Buenos Aires (Burn Center) is one of the reference hospitals of the Medical Radiological Emergency Response Network of Argentina. In the frame of an agreement between the Burn Center and the Nuclear Regulatory Authority of Argentina, a research project for an approach based on diagnosis and therapy of cutaneous radiation induced lesions is in progress. Individual radiosensitivity assessment was conducted in patients included in this research protocol that showed acute and/or late cutaneous reactions with grades 3 and 4 of the Toxicity criteria of the Radiation Therapy Oncology Group (RTOG) and the European organization for research and treatment of cancer (EORTC). DNA repair capacity and its kinetics were evaluated in human peripheral blood lymphocytes using alkaline comet assay and micronucleus test. In this paper, two representative cases, in which the research protocol was applied, are presented. Therapeutic response and its correlation with radiosensitivity test results are described. Case 1: female patient undergoing external radiotherapy for invasive ductal breast cancer that presented acute cutaneous radiotoxicity, grade 3 (confluent moist epithelitis, )that led to treatment break. Case 2: male patient undergoing coronary angioplasty (interventional radiology), which developed late cutaneous radiotoxicity, grade 4 (ulceration at the dorsal region). Patients were treated with: topic administration of trolamine and silver sulfadiazine with lidocaine, associated with systemic administration of pentoxiphiline and anti-oxidants. The therapeutic response was evaluated through clinical follow-up, serial photographic record and complementary tests (tele thermography and high frequency ultrasonography). Case 1 response was positive (favorable) with early local recovery and complete remission of signs and symptoms after 5 months. Both MN frequencies and comet assay showed values compatible with normal radiosensitivity

  8. Nanoparticle Drones to Target Lung Cancer with Radiosensitizers and Cannabinoids

    Directory of Open Access Journals (Sweden)

    Wilfred Ngwa

    2017-09-01

    Full Text Available Nanotechnology has opened up a new, previously unimaginable world in cancer diagnosis and therapy, leading to the emergence of cancer nanomedicine and nanoparticle-aided radiotherapy. Smart nanomaterials (nanoparticle drones can now be constructed with capability to precisely target cancer cells and be remotely activated with radiation to emit micrometer-range missile-like electrons to destroy the tumor cells. These nanoparticle drones can also be programmed to deliver therapeutic payloads to tumor sites to achieve optimal therapeutic efficacy. In this article, we examine the state-of-the-art and potential of nanoparticle drones in targeting lung cancer. Inhalation (INH (air versus traditional intravenous (“sea” routes of navigating physiological barriers using such drones is assessed. Results and analysis suggest that INH route may offer more promise for targeting tumor cells with radiosensitizers and cannabinoids from the perspective of maximizing damage to lung tumors cells while minimizing any collateral damage or side effects.

  9. Nanoparticle Drones to Target Lung Cancer with Radiosensitizers and Cannabinoids

    Science.gov (United States)

    Ngwa, Wilfred; Kumar, Rajiv; Moreau, Michele; Dabney, Raymond; Herman, Allen

    2017-01-01

    Nanotechnology has opened up a new, previously unimaginable world in cancer diagnosis and therapy, leading to the emergence of cancer nanomedicine and nanoparticle-aided radiotherapy. Smart nanomaterials (nanoparticle drones) can now be constructed with capability to precisely target cancer cells and be remotely activated with radiation to emit micrometer-range missile-like electrons to destroy the tumor cells. These nanoparticle drones can also be programmed to deliver therapeutic payloads to tumor sites to achieve optimal therapeutic efficacy. In this article, we examine the state-of-the-art and potential of nanoparticle drones in targeting lung cancer. Inhalation (INH) (air) versus traditional intravenous (“sea”) routes of navigating physiological barriers using such drones is assessed. Results and analysis suggest that INH route may offer more promise for targeting tumor cells with radiosensitizers and cannabinoids from the perspective of maximizing damage to lung tumors cells while minimizing any collateral damage or side effects. PMID:28971063

  10. Individual radiosensitivity does not correlate with radiation-induced apoptosis in lymphoblastoid cell lines or CD{sup 3+} lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Wistop, A.; Keller, U.; Grabenbauer, G.G.; Sauer, R.; Distel, L.V.R. [Dept. of Radiation Oncology, Friedrich Alexander Univ. Erlangen-Nuremberg, Erlangen (Germany); Sprung, C.N. [Div. of Research, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia)

    2005-05-01

    Background and purpose: spontaneous and radiation-induced apoptosis of lymphoblastoid cell lines (LCLs) derived from healthy donors, cancer patients and donors with radiosensitivity syndromes as well as CD{sup 3+} lymphocytes from patients with {>=} grade 3 late toxicity were investigated as a possible marker for the detection of individual radiosensitivity. These investigations are based on the hypothesis that hypersensitive patients have reduced levels of apoptosis after in vitro irradiation as a result of a defect in the signaling pathway. Material and methods: Epstein-Barr virus-(EBV-)transformed LCLs derived from five healthy donors, seven patients with heterozygous or homozygous genotype for ataxia-telangiectasia or Nijmegen breakage syndrome and five patients with {>=} grade 3 late toxicity (RTOG) were investigated. In addition, CD{sup 3+} lymphocytes from 21 healthy individuals and 18 cancer patients including five patients with a proven cellular hypersensitivity to radiation were analyzed. Cells were irradiated in vitro with a dose of 2 and 5 Gy and were incubated for 48 h. Apoptotic rates were measured by the TUNEL assay followed by customized image analysis. Results: four out of seven radiosensitivity syndrome patients were identified to have an increased cellular radiosensitivity as determined by reduced apoptotic rates after irradiation of their respective LCLs. Comparatively, only two of the five hypersensitive cancer patients were clearly identified by reduced apoptotic rates. Spontaneous apoptotic rates were very homogeneous among all 39 samples from controls and patients, while lymphocytes of all cancer patients showed significantly lower radiation-induced rates. Conclusion: only a subgroup of hypersensitive patients may be identified by reduction of radiation-induced apoptotic rate. It is concluded that the hypothesis according to which hypersensitive cells have reduced levels of apoptosis is only conditionally true. The authors suggest that this

  11. Genetic bases of the radiosensitivity of breast cancer

    International Nuclear Information System (INIS)

    Delaloge, S.; Marsiglia, H.

    2005-01-01

    Local-regional radiation therapy is one of the major therapeutic means in the management of breast cancer. Three questions however arise from the important advances, achieved in this domain in the past years. The first question concerns the possibilities to identify and overcome the radioresistance of a subset of tumours. The second question is how to recognize women likely to benefit from adjuvant radiation therapy, and therefore to diminish treatment indications in other groups. Finally, the third question is how to identify subjects at high risk for long term injury following breast irradiation, in order to adapt techniques and indications in such populations. The major advances of breast cancer molecular genetics in the past years should provide clinicians with tools to answer these important questions. In this paper, we review the molecular germ line (BRCA1, BRCA2, ATM,...) and somatic (p53, tyrosine kinase receptors, as well as actors of cell cycle, signal transduction, apoptosis, DNA repair...) main bases of breast cancer radiosensitivity. Recent methods of exploration of the genetic background of both the host and the tumours (gene and protein expression profiles) are also reviewed as major tools of breast cancer management in the next few years. (author)

  12. The inherited basis of human radiosensitivity

    International Nuclear Information System (INIS)

    Gatti, R.A.

    2001-01-01

    Certain individuals cannot tolerate 'conventional' doses of radiation therapy. This is known to be true of patients with ataxia-telangiectasia and ligase IV deficiency. Although in vitro testing may not correlate completely with clinical radiosensitivity, fibroblasts and lymphoblasts from patients with both of these disorders have been clearly shown to be radiosensitive. Using a colony survival assay (CSA) to test lymphoblastoid cells after irradiation with 1 Gy, a variety of other genetic disorders have been identified as strong candidates for clinical radiosensitivity, such as Nijmegen breakage syndrome, Mre11 deficiency, and Fanconi's anemia. These data are presented and considered as a starting-point for the inherited basis of human radiosensitivity

  13. Correlation between the parameters of radiosensitivity in human cancer cell lines

    International Nuclear Information System (INIS)

    Park, Woo Yoon; Kim, Won Dong; Min, Kyung Soo

    1998-01-01

    We conducted clonogenic assay using human cancer cell lines (MKN-45, PC-14, Y-79, HeLa) to investigate a correlation between the parameters of radiosensitivity. Human cancer cell lines were irradiated with single doses of 1, 2, 3, 5, 7 and 10Gy for the study of radiosensitivity and sublethal damage repair capacity was assessed with two fractions of 5Gy separated with a time interval of 0, 1, 2, 3, 4, 6 and 24 hours. Surviving fraction was assessed with clonogenic assay using Sperman-Karber method and mathematical analysis of survival curves was done with linear-quadratic (LQ), multitarget-single hit(MS) model and mean inactivation dose(D). Surviving fractions at 2Gy(SF2) were variable among the cell lines, ranged from 0.174 to 0.85. The SF2 of Y-79 was lowest and that of PC-14 was highest(p<0.05, t-test). LQ model analysis showed that the values of α for Y-79, MKN-45, HeLa and PC-14 were 0.603, 0.356, 0.275 and 0.102 respectively, and those of β were 0.005, 0.016, 0.025 and 0.027 respectively. Fitting to MS model showed that the values of Do for Y-79, MKN-45, HeLa and PC-14 were 1.59, 1.84, 1.88 and 2.52 respectively, and those of n were 0.97, 1.46, 1.52 and 1.69 respectively. The Ds calculated by Gauss-Laguerre method were 1.62, 2.37, 2.61 and 3.95 respectively. So the SF2 was significantly correlated with α, Do and D. Their Pearson correlation coefficiencics were -0.953 and 0.993, 0.999 respectively(p<0.05). Sublethal damage repair was saturated around 4 hours and recovery ratios (RR) at plateau phase ranged from 2 to 3.79. But RR was not correlated with SF2, α, β, Do, D. The intrinsic radiosensitivity was very different among the tested human cell lines. Y-79 was the most sensitive and PC-14 was the least sensitive. SF2 was well correlated with α, Do, and D. RR was high for MKN-45 and HeLa but had nothing to do with radiosensitivity parameters. These basic parameters can be used as baseline data for various in vitro radiobiological experiments

  14. Radiosensitivity and cell kinetics of the human solid cancer transplanted to nude mouse

    International Nuclear Information System (INIS)

    Ikeuchi, Shunji

    1983-01-01

    This study was undertaken to analyse the relationship between radiosensitivity and cell kinetics of human solid cancer in experimental nude mouse system. Four strains of tumors used for the experiment were poorly differentiated squamous cell carcinoma of the lung (Lu-9), oat cell carcinoma of the lung (Lu-24), well differentiated squamous cell carcinoma of the tongue (To-1) and moderately differentiated squamous cell carcinoma of the esophagus (Es-4) which were serially transplantable to BALB/c nude mice. Radiosensitivity was evaluated by tumor growth in terms of inhibition rate, histological change and host reaction after irradiation. Cell kinetics were studied by autoradiography with pulse administration of 3 H-thymidine to mice. Although Lu-24 was most radiosensitive, followed by To-1, Es-4 and Lu-9 in the order of sensitivity, it was suggested that they might be more radioresistant in nude mice without T-cell function than in human. Regarding squamous cell carcinomas, well differentiated type was more radiosensitive than poorly differentiated one. All of these tumors in nude mouse revealed distinct percent labeled mitosis curves with two clear peaks which were quite different from those in human body. Lu-24 showed a characteristic pattern with a long time lag before visible growth, short G 1 , and low growth fraction, compared to other three tumors. Three strains of squamous cell carcinoma demonstrated similar cell kinetic factors which were almost the same as those in human body reported previously. The differences in volume doubling time of tumor, growth fraction and cell loss factor were partially related to those of radiosensitivities among tumors except for Lu-24. The theoretical volume doubling time was proved to be most reliable for estimation of effectiveness of irradiation, but the labeling index was not a valuable indicator for it. (author)

  15. Expression of hPNAS-4 Radiosensitizes Lewis Lung Cancer

    International Nuclear Information System (INIS)

    Zeng Hui; Yuan Zhu; Zhu Hong; Li Lei; Shi Huashan; Wang Zi; Fan Yu; Deng Qian; Zeng Jianshuang; He Yinbo; Xiao Jianghong; Li Zhiping

    2012-01-01

    Purpose: This study aimed to transfer the hPNAS-4 gene, a novel apoptosis-related human gene, into Lewis lung cancer (LL2) and observe its radiosensitive effect on radiation therapy in vitro and in vivo. Methods and Materials: The hPNAS-4 gene was transfected into LL2 cells, and its expression was detected via western blot. Colony formation assay and flow cytometry were used to detect the growth and apoptosis of cells treated with irradiation/PNAS-4 in vitro. The hPNAS-4 gene was transferred into LL2-bearing mice through tail vein injection of the liposome/gene complex. The tumor volumes were recorded after radiation therapy. Proliferating cell nuclear antigen (PCNA) immunohistochemistry staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay were performed to detect the tumor cell growth and apoptosis in vivo. Results: The hPNAS-4 gene was successfully transferred into LL2 cells and tumor tissue, and its overexpressions were confirmed via western blot analysis. Compared with the control, empty plasmid, hPNAS-4, radiation, and empty plasmid plus radiation groups, the hPNAS-4 plus radiation group more significantly inhibited growth and enhanced apoptosis of LL2 cells in vitro and in vivo (P<.05). Conclusions: The hPNAS-4 gene was successfully transferred into LL2 cells and tumor tissue and was expressed in both LL2 cell and tumor tissue. The hPNAS-4 gene therapy significantly enhanced growth inhibition and apoptosis of LL2 tumor cells by radiation therapy in vitro and in vivo. Therefore, it may be a potential radiosensitive treatment of radiation therapy for lung cancer.

  16. Long-term results of treatment of patients with metronidazole and protracted radiotherapy: a base for comparative randomized studies with hypoxic radiosensitizers

    International Nuclear Information System (INIS)

    Karim, A.B.M.F.; Njo, K.H.

    1982-01-01

    From 1974 to 1978, a pilot study was undertaken in the Academic Hospital of the Free University of Amsterdam to evaluate the use of hypoxic radiosensitizer metronidazole given with conventional protracted radiotherapy. All patients had advanced malignancies, 70 head and neck cancers being available for long-term evaluation. Only four showed evidence of (reversible) neuropathy, including one patient with two attacks of reversible psychosis. With a minimum follow-up period of 30 months, the local control rates of some of these tumors appear to be encouraging and higher (54%) than usually obtained, without evidence of any long-term enhanced late effect of radiation or carcinogenesis. Clinical benefit has been persistently reported from metronidazole from a number of centers. Reports on other hypoxic radiosensitizers are not always clearly encouraging to date. In view of these facts, three-armed studies appear desirable and are being pursued

  17. The inherited basis of human radiosensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Gatti, R.A. [Univ. of California, School of Medicine, Los Angeles, CA (United States). Experimental Pathology

    2001-11-01

    Certain individuals cannot tolerate 'conventional' doses of radiation therapy. This is known to be true of patients with ataxia-telangiectasia and ligase IV deficiency. Although in vitro testing may not correlate completely with clinical radiosensitivity, fibroblasts and lymphoblasts from patients with both of these disorders have been clearly shown to be radiosensitive. Using a colony survival assay (CSA) to test lymphoblastoid cells after irradiation with 1 Gy, a variety of other genetic disorders have been identified as strong candidates for clinical radiosensitivity, such as Nijmegen breakage syndrome, Mre11 deficiency, and Fanconi's anemia. These data are presented and considered as a starting-point for the inherited basis of human radiosensitivity.

  18. Anemia, tumor hypoxemia, and the cancer patient

    International Nuclear Information System (INIS)

    Varlotto, John; Stevenson, Mary Ann

    2005-01-01

    Purpose: To review the impact of anemia/tumor hypoxemia on the quality of life and survival in cancer patients, and to assess the problems associated with the correction of this difficulty. Methods: MEDLINE searches were performed to find relevant literature regarding anemia and/or tumor hypoxia in cancer patients. Articles were evaluated in order to assess the epidemiology, adverse patient effects, anemia correction guidelines, and mechanisms of hypoxia-induced cancer cell growth and/or therapeutic resistance. Past and current clinical studies of radiosensitization via tumor oxygenation/hypoxic cell sensitization were reviewed. All clinical studies using multi-variate analysis were analyzed to show whether or not anemia and/or tumor hypoxemia affected tumor control and patient survival. Articles dealing with the correction of anemia via transfusion and/or erythropoietin were reviewed in order to show the impact of the rectification on the quality of life and survival of cancer patients. Results: Approximately 40-64% of patients presenting for cancer therapy are anemic. The rate of anemia rises with the use of chemotherapy, radiotherapy, and hormonal therapy for prostate cancer. Anemia is associated with reductions both in quality of life and survival. Tumor hypoxemia has been hypothesized to lead to tumor growth and resistance to therapy because it leads to angiogenesis, genetic mutations, resistance to apoptosis, and a resistance to free radicals from chemotherapy and radiotherapy. Nineteen clinical studies of anemia and eight clinical studies of tumor hypoxemia were found that used multi-variate analysis to determine the effect of these conditions on the local control and/or survival of cancer patients. Despite differing definitions of anemia and hypoxemia, all studies have shown a correlation between low hemoglobin levels and/or higher amounts of tumor hypoxia with poorer prognosis. Radiosensitization through improvements in tumor oxygenation/hypoxic cell

  19. Omega-3 fatty acid supplementation in cancer therapy. Does eicosapentanoic acid influence the radiosensitivity of tumor cells?

    Energy Technology Data Exchange (ETDEWEB)

    Manda, Katrin; Kriesen, Stephan; Hildebrandt, Guido [Rostock Univ. (Germany). Dept. of Radiotherapy; Fietkau, Rainer; Klautke, Gunther [Univ. Hospital Erlangen, Erlangen (Germany). Dept. of Radiation Oncology

    2011-02-15

    Purpose: The aim of this study was to evaluate whether the omega-3 polyunsaturated fatty acid cis-5,8,11,14,17-eicosapentanoic acid (EPA) can enhance the radiosensitivity of different human tumor cell lines. Materials and Methods: Colon adenocarcinoma cells HT-29, and two glioblastoma multiforme tumor cells T98G and U251 were cultured under standard conditions. Cell growth was observed during administration with different concentrations of EPA, using it as the free fatty acid dissolved in ethanol or bound to bovine serum albumin. To investigate the influence of EPA (free and bound) on radiosensitivity, tumor cells were pretreated 30 minutes or 24 hours prior to irradiation with the fatty acid. Cell survival was measured by colony-forming assays. Results: When combined with irradiation, incubation with EPA was found to result in enhanced radiosensitivity with substantial variation: while there was strong radiosensitization for HT-29 and U251 cells, almost no effect for T98G cells was observed. A marked radiosensitization was clearly dependent on the treatment schedule. Conclusion: The observations suggest that EPA is not only a nutritional adjuvant but also may be a potential candidate to enhance the efficacy of irradiation on human cancer cells. (orig.)

  20. Use of Mitochondria-Specific Dye MKT-077 as a Radiosensitizer to Preoperatively Treat Locally Advanced Breast Cancer

    National Research Council Canada - National Science Library

    Braun, Rodney D

    2007-01-01

    The major goal of this project is to determine if the rhodacyanine analog dye, MKT-077, can be used to inhibit breast cancer cell oxygen metabolism and raise tumor oxygen levels, thereby radiosensitizing the tumor...

  1. Use of Mitochondria-Specific Dye MKT-077 as a Radiosensitizer to Preoperatively Treat Locally Advanced Breast Cancer

    National Research Council Canada - National Science Library

    Braun, Rodney D

    2006-01-01

    The major goal of this project is to determine if the rhodacyanine analog dye, MKT-077, can be used to inhibit breast cancer cell oxygen metabolism and raise tumor oxygen levels, thereby radiosensitizing the tumor...

  2. Use of Mitochondria-Specific Dye MKT-077 as a Radiosensitizer to Preoperatively Treat Locally Advanced Breast Cancer

    National Research Council Canada - National Science Library

    Braun, Rodney D

    2008-01-01

    The major goal of this project is to determine if the rhodacyanine analog dye, MKT-077, can be used to inhibit breast cancer cell oxygen metabolism and raise tumor oxygen levels, thereby radiosensitizing the tumor...

  3. Radiosensitization In Vivo by Histone Deacetylase Inhibition with No Increase in Early Normal Tissue Radiation Toxicity.

    Science.gov (United States)

    Groselj, Blaz; Ruan, Jia-Ling; Scott, Helen; Gorrill, Jessica; Nicholson, Judith; Kelly, Jacqueline; Anbalagan, Selvakumar; Thompson, James; Stratford, Michael R L; Jevons, Sarah J; Hammond, Ester M; Scudamore, Cheryl L; Kerr, Martin; Kiltie, Anne E

    2018-02-01

    As the population ages, more elderly patients require radiotherapy-based treatment for their pelvic malignancies, including muscle-invasive bladder cancer, as they are unfit for major surgery. Therefore, there is an urgent need to find radiosensitizing agents minimally toxic to normal tissues, including bowel and bladder, for such patients. We developed methods to determine normal tissue toxicity severity in intestine and bladder in vivo , using novel radiotherapy techniques on a small animal radiation research platform (SARRP). The effects of panobinostat on in vivo tumor growth delay were evaluated using subcutaneous xenografts in athymic nude mice. Panobinostat concentration levels in xenografts, plasma, and normal tissues were measured in CD1-nude mice. CD1-nude mice were treated with drug/irradiation combinations to assess acute normal tissue effects in small intestine using the intestinal crypt assay, and later effects in small and large intestine at 11 weeks by stool assessment and at 12 weeks by histologic examination. In vitro effects of panobinostat were assessed by qPCR and of panobinostat, TMP195, and mocetinostat by clonogenic assay, and Western blot analysis. Panobinostat resulted in growth delay in RT112 bladder cancer xenografts but did not significantly increase acute (3.75 days) or 12 weeks' normal tissue radiation toxicity. Radiosensitization by panobinostat was effective in hypoxic bladder cancer cells and associated with class I HDAC inhibition, and protein downregulation of HDAC2 and MRE11. Pan-HDAC inhibition is a promising strategy for radiosensitization, but more selective agents may be more useful radiosensitizers clinically, resulting in fewer systemic side effects. Mol Cancer Ther; 17(2); 381-92. ©2017 AACR See all articles in this MCT Focus section, "Developmental Therapeutics in Radiation Oncology." ©2017 American Association for Cancer Research.

  4. Safety and efficacy of enzyme targeting intraoperative radiosensitization therapy (KORTUC-IORT) for advanced pancreatic cancer

    International Nuclear Information System (INIS)

    Nishioka, Akihito; Hamada, Norihiko; Kariya, Shinji; Ogawa, Yasuhiro

    2012-01-01

    We developed a new radiosensitizer injection containing hydrogen peroxide and sodium hyaluronate just followed by intraoperative radiotherapy (IORT) for locally advanced pancreatic cancer, named KORTUC-IORT (Kochi Oxydol-Radiation Therapy for Unresectable Carcinoma + IORT). Fourteen patients were treated with KORTUC-IORT, external beam radiotherapy (EBRT), and systemic chemotherapy. With KORTUC-IORT, the agent containing hydrogen peroxide and sodium hyaluronate, was injected into tumor tissue just prior to administration of IORT under ultrasonic guidance. All treatments related with KORTUC-IORT were well tolerated, with few adverse effects. One year survival rate is 67% and median survival period is 15 months. The present formulation can be delivered safely and effectively under the conditions used. (author)

  5. Radiosensitivity of fibroblasts obtained from a cafe-au-lait spot and normal-appearing skin of a patient with neurofibromatosis (NF-6)

    International Nuclear Information System (INIS)

    Hannan, M.A.; Smith, B.P.; Sigut, D.; Sackey, K.

    1990-01-01

    Fibroblast cells derived from a cafe-au-lait spot and normal-appearing skin of a neurofibromatosis (NF-6) patient were studied for radiosensitivity in comparison with two normal cell lines used as controls. No difference in radiosensitivity was observed between the patient's cell lines and the controls using acute gamma-irradiation. However, a markedly increased radiosensitivity of the fibroblasts obtained from the patient's skin of normal appearance was demonstrated after chronic gamma-irradiation. The cells from the cafe-au-lait spot showed intermediate sensitivity to chronic irradiation as compared with the control cell lines and the fibroblasts derived from the normal skin of the patient. These results showed the usefulness of chronic irradiation in detecting increased cellular radiosensitivity which may result from a unique DNA repair defect in an NF patient. We suggest that enhanced genetic changes in radiosensitive NF patients may lead to formation of cafe-au-lait lesions and certain tumors. Such a transformation may be associated with production of radiotolerant cells

  6. The Effect of VPA on Increasing Radiosensitivity in Osteosarcoma Cells and Primary-Culture Cells from Chemical Carcinogen-Induced Breast Cancer in Rats.

    Science.gov (United States)

    Liu, Guochao; Wang, Hui; Zhang, Fengmei; Tian, Youjia; Tian, Zhujun; Cai, Zuchao; Lim, David; Feng, Zhihui

    2017-05-10

    This study explored whether valproic acid (VPA, a histone deacetylase inhibitor) could radiosensitize osteosarcoma and primary-culture tumor cells, and determined the mechanism of VPA-induced radiosensitization. The working system included osteosarcoma cells (U2OS) and primary-culture cells from chemical carcinogen (DMBA)-induced breast cancer in rats; and clonogenic survival, immunofluorescence, fluorescent in situ hybridization (FISH) for chromosome aberrations, and comet assays were used in this study. It was found that VPA at the safe or critical safe concentration of 0.5 or 1.0 mM VPA could result in the accumulation of more ionizing radiation (IR)-induced DNA double strand breaks, and increase the cell radiosensitivity. VPA-induced radiosensitivity was associated with the inhibition of DNA repair activity in the working systems. In addition, the chromosome aberrations including chromosome breaks, chromatid breaks, and radial structures significantly increased after the combination treatment of VPA and IR. Importantly, the results obtained by primary-culture cells from the tissue of chemical carcinogen-induced breast cancer in rats further confirmed our findings. The data in this study demonstrated that VPA at a safe dose was a radiosensitizer for osteosarcoma and primary-culture tumor cells through suppressing DNA-double strand breaks repair function.

  7. Effect of microenviroment hypoxia on glioma cells radiosensitivity through cancer stem cell pathway

    International Nuclear Information System (INIS)

    Tong Liumei; Feng Libo; Lu Xueguan; Chen Liesong; Guo Xinwei; Tian Ye

    2010-01-01

    Objective: To investigate the effect of microenviroment hypoxia on glioma cells radiosensitivity through cancer stem pathway, and to explore the related mechanism. Methods: Glioma cell lines SHG44 and U251 were cultured in normoxia (20% O 2 ) or continuous hypoxia (1% O 2 ) for 12 and 24 h. The fraction of glioma cells with positive expression of CD133 was assayed by flow cytometry. The radiosensitivity of glioma cells was determined by clonogenic cell assay. Western blotting was used to investigate the expressions of HIF-1 α and its downstream gene Notch 1. Results: The fraction of glioma cells with positive expression of CD133 was higher after hypoxic culture for 12 and 24 h than that of the corresponding cells cultured in normoxia. Compared to the cells cultured in normoxia, SF 2 (survival fraction at 2 Gy) were enhanced significantly in SHG44 and U251 cells cultured in hypoxia for 12 and 24 h. The OER (oxygen-enhancement ratio) of SHG44 cells in hypoxia for 12 and 24 h was 1.54 and 1.38, respectively. The OER of U251 cells was 1.44 and 1.23, respectively. The radiosensitivity of these two cell line was decreased in hypoxia. The protein expressions of HIF-1 α and Notch 1 genes were elevated more significantly for cells cultured in hypoxia for 12 and 24 h than for those in normoxia. Conclusions: Microenviroment hypoxia could increase the radioresistance of glioma cells through enrichment of cancer stem cells, and HIF-1 α-Notch 1 signal pathway may play an important role in this process. (authors)

  8. Integration of a Radiosensitivity Molecular Signature Into the Assessment of Local Recurrence Risk in Breast Cancer

    International Nuclear Information System (INIS)

    Torres-Roca, Javier F.; Fulp, William J.; Caudell, Jimmy J.; Servant, Nicolas; Bollet, Marc A.; Vijver, Marc van de; Naghavi, Arash O.; Harris, Eleanor E.; Eschrich, Steven A.

    2015-01-01

    Purpose: Recently, we developed radiosensitivity (RSI), a clinically validated molecular signature that estimates tumor radiosensitivity. In the present study, we tested whether integrating RSI with the molecular subtype refines the classification of local recurrence (LR) risk in breast cancer. Methods and Materials: RSI and molecular subtype were evaluated in 343 patients treated with breast-conserving therapy that included whole-breast radiation therapy with or without a tumor bed boost (dose range 45-72 Gy). The follow-up period for patients without recurrence was 10 years. The clinical endpoint was LR-free survival. Results: Although RSI did not uniformly predict for LR across the entire cohort, combining RSI and the molecular subtype identified a subpopulation with an increased risk of LR: triple negative (TN) and radioresistant (reference TN-radioresistant, hazard ratio [HR] 0.37, 95% confidence interval [CI] 0.15-0.92, P=.02). TN patients who were RSI-sensitive/intermediate had LR rates similar to those of luminal (LUM) patients (HR 0.86, 95% CI 0.47-1.57, P=.63). On multivariate analysis, combined RSI and molecular subtype (P=.004) and age (P=.001) were the most significant predictors of LR. In contrast, integrating RSI into the LUM subtype did not identify additional risk groups. We hypothesized that radiation dose escalation was affecting radioresistance in the LUM subtype and serving as a confounder. An increased radiation dose decreased LR only in the luminal-resistant (LUM-R) subset (HR 0.23, 95% CI 0.05-0.98, P=.03). On multivariate analysis, the radiation dose was an independent variable only in the LUMA/B-RR subset (HR 0.025, 95% CI 0.001-0.946, P=.046), along with age (P=.008), T stage (P=.004), and chemotherapy (P=.008). Conclusions: The combined molecular subtype–RSI identified a novel molecular subpopulation (TN and radioresistant) with an increased risk of LR after breast-conserving therapy. We propose that the combination of RSI and

  9. Integration of a Radiosensitivity Molecular Signature Into the Assessment of Local Recurrence Risk in Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Torres-Roca, Javier F., E-mail: javier.torresroca@moffitt.org [Department of Radiation Oncology, Moffitt Cancer Center, Tampa, Florida (United States); Department of Chemical Biology and Molecular Medicine, Moffitt Cancer Center, Tampa, Florida (United States); Fulp, William J. [Department of Bioinformatics, Moffitt Cancer Center, Tampa, Florida (United States); Department of Biostatistics, Moffitt Cancer Center, Tampa, Florida (United States); Caudell, Jimmy J. [Department of Radiation Oncology, Moffitt Cancer Center, Tampa, Florida (United States); Servant, Nicolas [Institut Curie, INSERM U900, Paris (France); Mines ParisTech, Paris (France); Bollet, Marc A. [Institut Curie, INSERM U900, Paris (France); Vijver, Marc van de [Netherlands Cancer Institute, Amsterdam (Netherlands); Naghavi, Arash O. [Department of Radiation Oncology, Moffitt Cancer Center, Tampa, Florida (United States); Harris, Eleanor E. [East Carolina University, Greensborough, North Carolina (United States); Eschrich, Steven A. [Department of Bioinformatics, Moffitt Cancer Center, Tampa, Florida (United States)

    2015-11-01

    Purpose: Recently, we developed radiosensitivity (RSI), a clinically validated molecular signature that estimates tumor radiosensitivity. In the present study, we tested whether integrating RSI with the molecular subtype refines the classification of local recurrence (LR) risk in breast cancer. Methods and Materials: RSI and molecular subtype were evaluated in 343 patients treated with breast-conserving therapy that included whole-breast radiation therapy with or without a tumor bed boost (dose range 45-72 Gy). The follow-up period for patients without recurrence was 10 years. The clinical endpoint was LR-free survival. Results: Although RSI did not uniformly predict for LR across the entire cohort, combining RSI and the molecular subtype identified a subpopulation with an increased risk of LR: triple negative (TN) and radioresistant (reference TN-radioresistant, hazard ratio [HR] 0.37, 95% confidence interval [CI] 0.15-0.92, P=.02). TN patients who were RSI-sensitive/intermediate had LR rates similar to those of luminal (LUM) patients (HR 0.86, 95% CI 0.47-1.57, P=.63). On multivariate analysis, combined RSI and molecular subtype (P=.004) and age (P=.001) were the most significant predictors of LR. In contrast, integrating RSI into the LUM subtype did not identify additional risk groups. We hypothesized that radiation dose escalation was affecting radioresistance in the LUM subtype and serving as a confounder. An increased radiation dose decreased LR only in the luminal-resistant (LUM-R) subset (HR 0.23, 95% CI 0.05-0.98, P=.03). On multivariate analysis, the radiation dose was an independent variable only in the LUMA/B-RR subset (HR 0.025, 95% CI 0.001-0.946, P=.046), along with age (P=.008), T stage (P=.004), and chemotherapy (P=.008). Conclusions: The combined molecular subtype–RSI identified a novel molecular subpopulation (TN and radioresistant) with an increased risk of LR after breast-conserving therapy. We propose that the combination of RSI and

  10. Cooperative Enhancement of Radiosensitivity After Combined Treatment of 17-(Allylamino)-17-Demethoxygeldanamycin and Celecoxib in Human Lung and Colon Cancer Cell Lines

    Science.gov (United States)

    Kim, Young-Mee

    2012-01-01

    We investigated whether the combined treatment of 17-(allylamino)-17-demethoxygeldanamycin (17-AAG), an inhibitor of heat-shock protein 90 (hsp90), and celecoxib, an inhibitor of cyclooxygenase-2, can cooperatively enhance the radiosensitivity of various human cancer cells. Combined treatment with 17-AAG and celecoxib, at clinically relevant concentrations, cooperatively induced radiosensitization in all tested cancer cells, but not in normal cells. Cooperative radiosensitization by the drug combination was also shown in a human tumor xenograft system. We found that ataxia-telangiectasia and rad3-related (ATR) and ataxia-telangiectasia mutated (ATM) are novel client proteins of hsp90. Combined treatment with 17-AAG and celecoxib cooperatively induced downregulation of ATR and ATM. In conclusion, combined treatment with 17-AAG and celecoxib at clinically relevant concentrations may significantly enhance the therapeutic efficacy of ionizing radiation. PMID:21830942

  11. Axin gene methylation status correlates with radiosensitivity of lung cancer cells

    International Nuclear Information System (INIS)

    Yang, Lian-He; Stoecker, Maggie; Wang, Endi; Xu, Ke; Wang, En-Hua; Han, Yang; Li, Guang; Xu, Hong-Tao; Jiang, Gui-Yang; Miao, Yuan; Zhang, Xiu-Peng; Zhao, Huan-Yu; Xu, Zheng-Fan

    2013-01-01

    We previously reported that Axin1 (Axin) is down-regulated in many cases of lung cancer, and X-ray irradiation increased Axin expression and inhibited lung cancer cells. The mechanisms, however, were not clear. Four lung cancer cell lines were used to detect the methylation status of Axin with or without X-ray treatment. Real-time PCR was used to quantify the expression of Axin, and western blot analysis was applied to measure protein levels of Axin, β-catenin, Cyclin D1, MMP-7, DNMTS, MeCP2 and acetylated histones. Flow cytometric analysis, colony formation assay, transwell assay and xenograft growth experiment were used to study the biological behavior of the cells with hypermethylated or unmethylated Axin gene after X-ray treatment. Hypermethylated Axin gene was detected in 2 of 4 cell lines, and it correlated inversely with Axin expression. X-ray treatment significantly up-regulated Axin expression in H446 and H157 cells, which possess intrinsic hypermethylation of the Axin gene (P<0.01), but did not show up-regulation in LTE and H460 cells, which have unmethylated Axin gene. 2Gy X-ray significantly reduced colony formation (from 71% to 10.5%) in H157 cells, while the reduction was lower in LTE cells (from 71% to 20%). After X-ray irradiation, xenograft growth was significantly decreased in H157 cells (from 1.15 g to 0.28 g) in comparison with LTE cells (from 1.06 g to 0.65 g). Significantly decreased cell invasiveness and increased apoptosis were also observed in H157 cells treated with X-ray irradiation (P<0.01). Down-regulation of DNMTs and MeCP2 and up-regulation of acetylated histones could be detected in lung cancer cells. X-ray-induced inhibition of lung cancer cells may be mediated by enhanced expression of Axin via genomic DNA demethylation and histone acetylation. Lung cancer cells with a different methylation status of the Axin gene showed different radiosensitivity, suggesting that the methylation status of the Axin gene may be one important factor

  12. Cellular radiosensitivity of small-cell lung cancer cell lines

    International Nuclear Information System (INIS)

    Krarup, Marianne; Poulsen, Hans Skovgaard; Spang-Thomsen, Mogens

    1997-01-01

    Purpose: The objective of this study was to determine the radiobiological characteristics of a panel of small-cell lung cancer (SCLC) cell lines by use of a clonogenic assay. In addition, we tested whether comparable results could be obtained by employing a growth extrapolation method based on the construction of continuous exponential growth curves. Methods and Materials: Fifteen SCLC cell lines were studied, applying a slightly modified clonogenic assay and a growth extrapolation method. A dose-survival curve was obtained for each experiment and used for calculating several survival parameters. The multitarget single hit model was applied to calculate the cellular radiosensitivity (D 0 ), the capacity for sublethal damage repair (D q ), and the extrapolation number (n). Values for α and β were determined from best-fit curves according to the linear-quadratic model and these values were applied to calculate the surviving fraction after 2-Gy irradiation (SF 2 ). Results: In our investigation, the extrapolation method proved to be inappropriate for the study of in vitro cellular radiosensitivity due to lack of reproducibility. The results obtained by the clonogenic assay showed that the cell lines studied were radiobiologically heterogeneous with no discrete features of the examined parameters including the repair capacity. Conclusion: The results indicate that SCLC tumors per se are not generally candidates for hyperfractionated radiotherapy

  13. SU-E-T-668: Radiosensitizing Effect of Bosutinib On Prostate and Colon Cancers: A Pilot in Vitro Study

    Energy Technology Data Exchange (ETDEWEB)

    Wang, B; Cvetkovic, D; Chen, L; Ma, C [Fox Chase Cancer Center, Philadelphia, PA (United States); Wang, C [Fox Chase Cancer Center, Philadelphia, PA (United States); West China Hospital, Sichuan University, Chengdu, Sichuan (China)

    2015-06-15

    Purpose: Recently it has been reported that Bosutinib, a clinical kinase inhibitor, can enhance the tumor cell chemosensitivity by overriding DNA damage checkpoints. However, to the best of our knowledge, there is no report on its effect on cell radiosensitivity in the literature. The objective of the present study is to determine whether Bosutinib has the potential to be used as a radiosensitizer for various cancer cell lines. Methods: In this study, we tested 4 cell lines derived from human prostate (LNCaP, PC-3, DU-145) and colon (HT-29) cancers. The cells were seeded into 12-well plates 24 hours prior to the radiation treatments. For each cell line, we designed 4 study groups, namely, the control, Bosutinib, radiotherapy, and radiotherapy+Bosutinib groups. We used 6 MV photon beams from a Siemens Artiste accelerator to deliver 2 Gy dose in one fraction to the cells in the radiotherapy and radiotherapy+Bosutinib groups. Immediately after irradiation, the cells in the radiotherapy+Bosutinib group were treated with Bosutinib (1µM) for 3 hours. The cell survival was evaluated through clonogenic assays. Results: The cell survival rates of the LNCaP, PC-3, DU-145, and HT-29 cells were found to be 21%, 92%, 76%, and 93% for the radiotherapy group; 21%, 69%, 67%, and 81% for the radiotherapy+Bosutinib group; and 103%, 107%, 86%, and 102% for the Bosutinib group, respectively. Although synergetic cell killing was not seen for the LNCaP and DU-145 cell lines in this study, the cell survival data from the clonogenic assay indicated that Bosutinib could enhance the sensitivity of PC-3 and HT-29 cells to radiation treatment. Conclusion: Our preliminary results demonstrated the possibility of Bosutinib as a radiosensitizer for certain prostate and colon cancers, which are resistant to radiotherapy. Further studies are warranted to quantify the radiosensitizing effect of Bosutinib.

  14. SU-E-T-668: Radiosensitizing Effect of Bosutinib On Prostate and Colon Cancers: A Pilot in Vitro Study

    International Nuclear Information System (INIS)

    Wang, B; Cvetkovic, D; Chen, L; Ma, C; Wang, C

    2015-01-01

    Purpose: Recently it has been reported that Bosutinib, a clinical kinase inhibitor, can enhance the tumor cell chemosensitivity by overriding DNA damage checkpoints. However, to the best of our knowledge, there is no report on its effect on cell radiosensitivity in the literature. The objective of the present study is to determine whether Bosutinib has the potential to be used as a radiosensitizer for various cancer cell lines. Methods: In this study, we tested 4 cell lines derived from human prostate (LNCaP, PC-3, DU-145) and colon (HT-29) cancers. The cells were seeded into 12-well plates 24 hours prior to the radiation treatments. For each cell line, we designed 4 study groups, namely, the control, Bosutinib, radiotherapy, and radiotherapy+Bosutinib groups. We used 6 MV photon beams from a Siemens Artiste accelerator to deliver 2 Gy dose in one fraction to the cells in the radiotherapy and radiotherapy+Bosutinib groups. Immediately after irradiation, the cells in the radiotherapy+Bosutinib group were treated with Bosutinib (1µM) for 3 hours. The cell survival was evaluated through clonogenic assays. Results: The cell survival rates of the LNCaP, PC-3, DU-145, and HT-29 cells were found to be 21%, 92%, 76%, and 93% for the radiotherapy group; 21%, 69%, 67%, and 81% for the radiotherapy+Bosutinib group; and 103%, 107%, 86%, and 102% for the Bosutinib group, respectively. Although synergetic cell killing was not seen for the LNCaP and DU-145 cell lines in this study, the cell survival data from the clonogenic assay indicated that Bosutinib could enhance the sensitivity of PC-3 and HT-29 cells to radiation treatment. Conclusion: Our preliminary results demonstrated the possibility of Bosutinib as a radiosensitizer for certain prostate and colon cancers, which are resistant to radiotherapy. Further studies are warranted to quantify the radiosensitizing effect of Bosutinib

  15. Insulin-like growth factor stimulation increases radiosensitivity of a pancreatic cancer cell line through endoplasmic reticulum stress under hypoxic conditions

    International Nuclear Information System (INIS)

    Isohashi, Fumiaki; Endo, Hiroko; Mukai, Mutsuko; Inoue, Masahiro; Inoue, Takehiro

    2008-01-01

    Tumor hypoxia is an obstacle to radiotherapy. Radiosensitivity under hypoxic conditions is determined by molecular oxygen levels, as well as by various biological cellular responses. The insulin-like growth factor (IGF) signaling pathway is a widely recognized survival signal that confers radioresistance. However, under hypoxic conditions the role of IGF signaling in radiosensitivity is still poorly understood. Here, we demonstrate that IGF-II stimulation decreases clonogenic survival under hypoxic conditions in the pancreatic cancer cell lines AsPC-1 and Panc-1, and in the human breast cancer cell line MCF-7. IGF treatment under hypoxic conditions suppressed increased radiation sensitivity in these cell lines by pharmacologically inhibiting the phosphoinositide 3-kinase-mammalian target of rapamycin pathway, a major IGF signal-transduction pathway. Meanwhile, IGF-II induced the endoplasmic reticulum stress response under hypoxia, including increased protein levels of CHOP and ATF4, mRNA levels of CHOP, GADD34, and BiP as well as splicing levels of XBP-1. The response was suppressed by inhibiting phosphoinositide 3-kinase and mammalian target of rapamycin activity. Overexpression of CHOP in AsPC-1 cells increased radiation sensitivity by IGF-II simulation under hypoxic conditions, whereas suppression of CHOP expression levels with small hairpin RNA or a dominant negative form of a proline-rich extensin-like receptor protein kinase in hypoxia decreased IGF-induced radiosensitivity. IGF-induced endoplasmic reticulum stress contributed to radiosensitization independent of cell cycle status. Taken together, IGF stimulation increased radiosensitivity through the endoplasmic reticulum stress response under hypoxic conditions. (author)

  16. Fulvestrant radiosensitizes human estrogen receptor-positive breast cancer cells

    International Nuclear Information System (INIS)

    Wang, Jing; Yang, Qifeng; Haffty, Bruce G.; Li, Xiaoyan; Moran, Meena S.

    2013-01-01

    Highlights: ► Fulvestrant radiosensitizes MCF-7 cells. ► Fulvestrant increases G1 arrest and decreases S phase in MCF-7 cells. ► Fulvestrant down-regulates DNA-PKcs and RAD51 in MCF-7 cells. -- Abstract: The optimal sequencing for hormonal therapy and radiation are yet to be determined. We utilized fulvestrant, which is showing promise as an alternative to other agents in the clinical setting of hormonal therapy, to assess the cellular effects of concomitant anti-estrogen therapy (fulvestrant) with radiation (F + RT). This study was conducted to assess the effects of fulvestrant alone vs. F + RT on hormone-receptor positive breast cancer to determine if any positive or negative combined effects exist. The effects of F + RT on human breast cancer cells were assessed using MCF-7 clonogenic and tetrazolium salt colorimetric (MTT) assays. The assays were irradiated with a dose of 0, 2, 4, 6 Gy ± fulvestrant. The effects of F + RT vs. single adjuvant treatment alone on cell-cycle distribution were assessed using flow cytometry; relative expression of repair proteins (Ku70, Ku80, DNA-PKcs, Rad51) was assessed using Western Blot analysis. Cell growth for radiation alone vs. F + RT was 0.885 ± 0.013 vs. 0.622 ± 0.029 @2 Gy, 0.599 ± 0.045 vs. 0.475 ± 0.054 @4 Gy, and 0.472 ± 0.021 vs. 0.380 ± 0.018 @6 Gy RT (p = 0.003). While irradiation alone induced G2/M cell cycle arrest, the combination of F + RT induced cell redistribution in the G1 phase and produced a significant decrease in the proportion of cells in G2 phase arrest and in the S phase in breast cancer cells (p < 0.01). Furthermore, levels of repair proteins DNA-PKcs and Rad51 were significantly decreased in the cells treated with F + RT compared with irradiation alone. F + RT leads to a decrease in the surviving fraction, increased cell cycle arrest, down regulating of nonhomologous repair protein DNA-PKcs and homologous recombination repair protein RAD51. Thus, our findings suggest that F + RT

  17. Chemical radiosensitizers with special reference to metronidazole

    International Nuclear Information System (INIS)

    Sharma, R.; Purohit, O.P.; Nair, C.R.; Dutta, T.K.

    1982-01-01

    An attempt at rationalisation of drug dose schedule for a radiosensitizer in a cancer clinic is attempted. A prospective analysis of tissue tolerance, response data and complications of the two groups of patients (treated by oral and high intermittent rectal routes) was made with matched control. The study group has definite use of metronidazole. It is further highlighted that there is an additional advantage of the rectal administration route of the drug as compared to that of the oral route. This is a preliminary communication. (author)

  18. Knock-down of miR-221 and miR-222 in the radiosensitization of breast cancer cells

    International Nuclear Information System (INIS)

    Zhang Chunzhi; Kang Chunsheng; Cao Yongzhen; Pu Peiyu; Lu Zhonghong; Du Yue

    2009-01-01

    Objective: To investigate the radiosensitizing effect of knock-down of miR-221 miR-222 on MCF-7 human breast cancer cells and explore the possible mechanism. Methods: Antisense oligonucleotides of miR-221 and miR-222 (AS-miR-221 and AS-miR-222), mediated by lipofectamine, were transfected to MCF-7 cells to knock down miR-221 and miR-222, Northern blotting was conducted to detect the expression of miR-221 and miR-222 in transfected cells. The cell apoptosis was detected by flow cytometry and Caspase-3 and Caspase-7 activity assay. Clonogenic assay was used to measure the sensitizing enhancement ratio. Target genes of miR-221 and miR-222 relevant to radio-sensitivity were searched using bioinformatics analysis. The targeted protein expression was determined by Western blot analysis. Results: The expression of miR-221 and miR-222 in the AS-miR-221/222 cells determined by Northern blotting was significantly reduced. Compared with the control group, the cell apoptosis and mitotic cell death after the radiation were significantly higher in AS-miR-221/222 cells. The sensitizing enhancement ratio was 1.87. Based on bioinformatics analysis, PTEN was a target gene of miR-221 and miR-222 which could enhance the radiosensitivity of MCF-7 cells. In AS-miR-221/222 cells, the expression of PTEN was up-regulated while pAkt down-regulated. Conclusions: AS-miR-221 and AS-miR-222 may enhance the radiosensitivity of MCF-7 breast cancer cells by up-regulating the expression of PTEN. (authors)

  19. Evaluation of different biomarkers to predict individual radiosensitivity in an inter-laboratory comparison--lessons for future studies.

    Directory of Open Access Journals (Sweden)

    Burkhard Greve

    Full Text Available Radiotherapy is a powerful cure for several types of solid tumours, but its application is often limited because of severe side effects in individual patients. With the aim to find biomarkers capable of predicting normal tissue side reactions we analysed the radiation responses of cells from individual head and neck tumour and breast cancer patients of different clinical radiosensitivity in a multicentric study. Multiple parameters of cellular radiosensitivity were analysed in coded samples of peripheral blood lymphocytes (PBLs and derived lymphoblastoid cell lines (LCLs from 15 clinical radio-hypersensitive tumour patients and compared to age- and sex-matched non-radiosensitive patient controls and 15 lymphoblastoid cell lines from age- and sex- matched healthy controls of the KORA study. Experimental parameters included ionizing radiation (IR-induced cell death (AnnexinV, induction and repair of DNA strand breaks (Comet assay, induction of yH2AX foci (as a result of DNA double strand breaks, and whole genome expression analyses. Considerable inter-individual differences in IR-induced DNA strand breaks and their repair and/or cell death could be detected in primary and immortalised cells with the applied assays. The group of clinically radiosensitive patients was not unequivocally distinguishable from normal responding patients nor were individual overreacting patients in the test system unambiguously identified by two different laboratories. Thus, the in vitro test systems investigated here seem not to be appropriate for a general prediction of clinical reactions during or after radiotherapy due to the experimental variability compared to the small effect of radiation sensitivity. Genome-wide expression analysis however revealed a set of 67 marker genes which were differentially induced 6 h after in vitro-irradiation in lymphocytes from radio-hypersensitive and non-radiosensitive patients. These results warrant future validation in larger

  20. Clinical experience with the radiosensitizer misonidazole

    International Nuclear Information System (INIS)

    Kogelnik, D.; Szepesi, T.; Kaercher, K.H.; Seitz, W.

    1979-01-01

    From April 1976 to June 1978, 74 cancer patients were treated with multiple doses of misonidazole at the University Clinic for Radiotherapy and Radiobiology of Vienna. Thirtyone patients had inoperable brain tumors or high-grade astrocytomas, the remaining patients suffered from late stages of various extracerebral malignancies. All patients were hospitalized and thoroughly examined for possible side-effects of this currently most promising hypoxic cell radiosensitizer. Neurotoxicity, principally the development of peripheral neuropathies, is the most important limiting factor in the clinical application of misonidazole. With total doses of 12 g/m 2 of surface area a low and acceptable incidence of neuropathies is seen. By extension of the over-all treatment time to 6-8 weeks the total dose may be increased to 15 g/m 2 . (orig.) 891 MG/orig. 892 RDG [de

  1. Increased chromosome radiosensitivity during pregnancy

    International Nuclear Information System (INIS)

    Ricoul, Michelle; Sabatier, Laure; Dutrillaux, Bernard

    1997-01-01

    It was necessary to consider the risks of exposure of pregnant women, not only in relation to the child, but also in relation to their own hypersensitivity. We have demonstrated that pregnancy increases radiosensitivity of chromosome in the mouse at the end of gestation. This is of importance since it may have implications on radioprotection of pregnant women and give experimental guidelines to the problems of hypersensitivity to drugs and cancer aggravation during pregnancy. Blood obtained from women at various times of pregnancy was exposed to ionizing radiations. By comparison to non-pregnant women, an increase in chromosome breakage was observed in metaphases from lymphocytes, after short-term culture in the presence of the serum of the same donor. Immediately after delivery, this increase in radiosensitivity disappeared. In a prospective study, serial analyses showed a very strong correlation between the amount of pregnancy hormones, progesterone in particular, and the increase in radiosensitivity. Pregnant women may have an increased sensitivity to ionizing radiation during the second half of their pregnancy. This study provides the first evidence in human that radiosensitivity may vary in relation to physiological conditions

  2. SHP1-mediated cell cycle redistribution inhibits radiosensitivity of non-small cell lung cancer

    International Nuclear Information System (INIS)

    Cao, Rubo; Ding, Qian; Li, Pindong; Xue, Jun; Zou, Zhenwei; Huang, Jing; Peng, Gang

    2013-01-01

    Radioresistance is the common cause for radiotherapy failure in non-small cell lung cancer (NSCLC), and the degree of radiosensitivity of tumor cells is different during different cell cycle phases. The objective of the present study was to investigate the effects of cell cycle redistribution in the establishment of radioresistance in NSCLC, as well as the signaling pathway of SH2 containing Tyrosine Phosphatase (SHP1). A NSCLC subtype cell line, radioresistant A549 (A549S1), was induced by high-dose hypofractionated ionizing radiations. Radiosensitivity-related parameters, cell cycle distribution and expression of cell cycle-related proteins and SHP1 were investigated. siRNA was designed to down-regulate SHP1expression. Compared with native A549 cells, the proportion of cells in the S phase was increased, and cells in the G0/G1 phase were consequently decreased, however, the proportion of cells in the G2/M phase did not change in A549S1 cells. Moreover, the expression of SHP1, CDK4 and CylinD1 were significantly increased, while p16 was significantly down-regulated in A549S1 cells compared with native A549 cells. Furthermore, inhibition of SHP1 by siRNA increased the radiosensitivity of A549S1 cells, induced a G0/G1 phase arrest, down-regulated CDK4 and CylinD1expressions, and up-regulated p16 expression. SHP1 decreases the radiosensitivity of NSCLC cells through affecting cell cycle distribution. This finding could unravel the molecular mechanism involved in NSCLC radioresistance

  3. Enhanced apoptosis and radiosensitization by combined 13-CIS-retinoic acid and interferon-α2a; role of RAR-β gene

    International Nuclear Information System (INIS)

    Ryu, Samuel; Stein, Joseph P.; Chung, Chung T.; Lee, Yong J.; Kim, Jae Ho

    2001-01-01

    Purpose: Combined use of 13-cis-retinoic acid (cRA) and interferon-α2a (IFNα) induced significant radiosensitization in human cervical cancer ME-180 cell line, whereas it failed to achieve similar radiation enhancement in HeLa cells. The differential radiosensitization could be from the difference of retinoic acid receptor (RAR) expression because RAR-β was highly expressed in ME-180 cells in contrast to the HeLa cells where RAR-β was not detectable. We examined the role of this gene in mediating radiosensitization by cRA and IFNα, and explored the mechanism of radiation-induced cell killing. Methods and Materials: Human cervical cancer cell lines, ME-180 and HeLa, were treated with cRA and IFNα followed by radiation. Apoptosis and radiosensitization were quantitated by TUNEL assay (in situ DNA nick end labeling) and colony-forming ability of surviving cells. The cells were transfected with bcl-2 gene and RAR-β gene to test the role of these genes in mediating radiosensitization and apoptosis. Results: Synergistic radiosensitization and apoptosis was observed by combined use of cRA and IFNα with radiation in ME-180 cells which express high level of RAR-β mRNA, whereas these were not seen in HeLa cells where RAR-β mRNA is not detectable. Both radiosensitization and apoptosis were abolished by bcl-2 gene in ME-180 cells. RAR-β gene transfection induced similar radiation enhancement and apoptosis in HeLa cells. Conclusion: Apoptosis and radiation response were enhanced in the cells with high level of RAR-β mRNA expression. The RAR-β gene appears to mediate the radiation-induced apoptosis by cRA and IFNα. These findings indicate that presence of RAR-β in the cancer cells could be exploited for patient selection in using these drugs for apoptosis and radiosensitization

  4. 53BP1 loss suppresses the radiosensitizing effect of icotinib hydrochloride in colorectal cancer cells.

    Science.gov (United States)

    Huang, Ai; Yao, Jing; Liu, Tao; Lin, Zhenyu; Zhang, Sheng; Zhang, Tao; Ma, Hong

    2018-04-01

    This study aimed to investigate the influence of the expression of P53-binding protein 1 (53BP1), a key component in DNA damage repair pathways, on the radiosensitizing effect of icotinib hydrochloride in colorectal cancer and to elucidate the mechanisms underlying this influence. Real-time RT-PCR and Western blotting were performed to verify the gene-knockout effect of 53BP1 small hairpin RNA (ShRNA), and colony formation assay was employed to investigate the influence of 53BP1 downregulation on the radiosensitizing effect of icotinib hydrochloride in HCT116 cells. Cell apoptosis, cell cycle distributions, and histone H2AX (γ-H2AX) fluorescence foci after 53BP1 knockdown were evaluated. Relative protein expression in the ataxia telangiectasia mutated kinase (ATM)-checkpoint kinase-2 (CHK2)-P53 pathway was measured by Western blot analysis to unravel the molecular mechanisms linking the pathway to the above phenomena. Icotinib hydrochloride increased the radiosensitivity of HCT116 cells; however, this effect was suppressed by the downregulation of 53BP1 expression, a change that inhibited cell apoptosis, increased the percentage of HCT116 cells arrested in S-phase and inhibited the protein expression of key molecules in the ATM-CHK2-P53 apoptotic pathway. Our studies confirmed that the loss of 53BP1 serves as a negative regulator of the radiosensitizing effect of icotinib in part by suppressing the ATM-CHK2-P53 apoptotic pathway.

  5. Differences in radiosensitivity between three HER2 overexpressing cell lines

    International Nuclear Information System (INIS)

    Steffen, Ann-Charlott; Tolmachev, Vladimir; Stenerloew, Bo; Goestring, Lovisa; Palm, Stig; Carlsson, Joergen

    2008-01-01

    HER2 is a potential target for radionuclide therapy, especially when HER2 overexpressing breast cancer cells are resistant to Herceptin registered treatment. Therefore, it is of interest to analyse whether HER2 overexpressing tumour cells have different inherent radiosensitivity. The radiosensitivity of three often used HER2 overexpressing cell lines, SKOV-3, SKBR-3 and BT-474, was analysed. The cells were exposed to conventional photon irradiation, low linear energy transfer (LET), to characterise their inherent radiosensitivity. The analysis was made with clonogenic survival and growth extrapolation assays. The cells were also exposed to alpha particles, high LET, from 211 At decays using the HER2-binding affibody molecule 211 At-(Z HER2:4 ) 2 as targeting agent. Assays for studies of internalisation of the affibody molecule were applied. SKOV-3 cells were most radioresistant, SKBR-3 cells were intermediate and BT-474 cells were most sensitive as measured with the clonogenic and growth extrapolation assays after photon irradiation. The HER2 dependent cellular uptake of 211 At was qualitatively similar for all three cell lines. However, the sensitivity to the alpha particles from 211 At differed; SKOV-3 was most resistant, SKBR-3 intermediate and BT-474 most sensitive. These differences were unexpected because it is assumed that all types of cells should have similar sensitivity to high-LET radiation. The sensitivity to alpha particle exposure correlated with internalisation of the affibody molecule and with size of the cell nucleus. There can be differences in radiosensitivity, which, if they also exist between patient breast cancer cells, are important to consider for both conventional radiotherapy and for HER2-targeted radionuclide therapy. (orig.)

  6. In vivo radiosensitization by diethyldithiocarbamate

    International Nuclear Information System (INIS)

    Kent, C.R.; Blekkenhorst, G.H.

    1988-01-01

    Diethyldithiocarbamate (DDC) has been suggested to have both radiosensitizing (due to superoxide dismutase (SOD) inhibition) and radioprotective properties. We have studied the activity of SOD up to 24 h after intratumoral administration of 50, 100, 150, and 300 mg/kg DDC in 3-methylcholanthrene-induced tumors in BALB/c mice. Maximal inhibition of SOD (8% of control) was obtained 1 h after administration of 100 mg/kg DDC. Tumor response to DDC and X irradiation was assessed using a tumor growth-delay assay, after 11 Gy 100-kVp X rays given up to 24 h after DDC administration. Radiation-induced tumor growth delay (7.11 +/- 1.76 days) was enhanced only when tumors were irradiated 2-4 h after 50 mg/kg DDC. When higher doses of DDC were used, tumor cure was noted when DDC was injected 1-6 h before irradiation. We suggest our findings are consistent with radiosensitization being due to SOD inhibition, but that if insufficient time is allowed between DDC injection and irradiation, the sensitization is masked by a radioprotective effect. We believe that further investigations as to the therapeutic potential of DDC in human patients with cancer are warranted

  7. Biomarkers of oxidative stress and their application for assessment of individual radiosensitivity

    International Nuclear Information System (INIS)

    Haghdoost, S.; Czene, S.; Harms-Ringdahl, M.; Naslund, I.; Skog, S.

    2003-01-01

    The main biological effect of ionizing radiation is the induction of different types of DNA damages. Besides strand breaks, different types of chemical changes of the deoxynucleotides appear, i.e.base-damages, induced by free radicals. One common base-damage is 8-hydroxy-2'-deoxyguanosine (8-oxo-dG). 8-oxo-dG is removed from the DNA by the process of base and nucleotide excision repair and released from the cell. In our previous study we have shown that excretion of 8-oxo-dG (measured by HPLC-EC) into urine is significantly different in patients showing minor radiosensitivity during the first 6-7 days of radiotherapy as compared to patients with pronounced reactions. This information could be advantageous for adjustment of the total dose and add other therapy modalities and/or treatments to benefit cancer patients. We report herein on the evaluation of a novel ELISA approach for the detection of 8-oxo-dG in human serum. Background data on 8-oxo-dG levels in serum from healthy individuals and breast cancer patients will be discussed. Dose response curves, after irradiation of whole blood in vitro, for evaluation of individual radiosensitivity for both groups will also be discussed

  8. On the Path to Seeking Novel Radiosensitizers

    International Nuclear Information System (INIS)

    Katz, David; Ito, Emma; Liu Feifei

    2009-01-01

    Radiation therapy is a highly effective cancer treatment modality, and extensive investigations have been undertaken over the years to augment its efficacy in the clinic. This review summarizes the current understanding of the biologic bases underpinning many of the clinically used radiosensitizers. In addition, this review illustrates how the advent of innovative, high-throughput technologies with integration of different disciplines could be harnessed for an expeditious discovery process for novel radiosensitizers, providing an exciting future for such pursuits in radiation biology and oncology

  9. Radiosensitivity in Fanconi's anemia patients

    International Nuclear Information System (INIS)

    Alter, Blanche P.

    2002-01-01

    The risks of radiation therapy in patients with Fanconi's anemia who have cancer are not clear. Possible toxicity was reported in six of 14 patients: 1/1 with vaginal cancer, 4/10 with head and neck or esophageal cancer, and 1/3 with oral cancer following bone marrow transplant

  10. Garcinol, a Histone Acetyltransferase Inhibitor, Radiosensitizes Cancer Cells by Inhibiting Non-Homologous End Joining

    Energy Technology Data Exchange (ETDEWEB)

    Oike, Takahiro [Division of Multistep Carcinogenesis, National Cancer Center Research Institute, Chuo-ku, Tokyo (Japan); Division of Genome Biology, National Cancer Center Research Institute, Chuo-ku, Tokyo (Japan); Department of Radiation Oncology, Gunma University Graduate School of Medicine, Maebashi, Gunma (Japan); Ogiwara, Hideaki [Division of Genome Biology, National Cancer Center Research Institute, Chuo-ku, Tokyo (Japan); Torikai, Kohta [Gunma University Heavy Ion Medical Center, Maebashi, Gunma (Japan); Nakano, Takashi [Department of Radiation Oncology, Gunma University Graduate School of Medicine, Maebashi, Gunma (Japan); Yokota, Jun [Division of Multistep Carcinogenesis, National Cancer Center Research Institute, Chuo-ku, Tokyo (Japan); Kohno, Takashi, E-mail: tkkohno@ncc.go.jp [Division of Genome Biology, National Cancer Center Research Institute, Chuo-ku, Tokyo (Japan)

    2012-11-01

    Purpose: Non-homologous end joining (NHEJ), a major pathway used to repair DNA double-strand breaks (DSBs) generated by ionizing radiation (IR), requires chromatin remodeling at DSB sites through the acetylation of histones by histone acetyltransferases (HATs). However, the effect of compounds with HAT inhibitory activities on the DNA damage response (DDR), including the NHEJ and cell cycle checkpoint, as well as on the radiosensitivity of cancer cells, remains largely unclear. Here, we investigated whether garcinol, a HAT inhibitor found in the rinds of Garcinia indica fruit (called mangosteens), has effects on DDR, and whether it can be used for radiosensitization. Methods and Materials: The following assays were used to examine the effect of garcinol on the inhibition of DSB repair, including the following: a conventional neutral comet assay; a cell-based assay recently developed by us, in which NHEJ repair of DSBs on chromosomal DNA was evaluated; the micrococcal nuclease sensitivity assay; and immunoblotting for autophosphorylation of DNA-dependent protein kinase catalytic subunit (DNA-PKcs). We assessed the effect of garcinol on the cell cycle checkpoint after IR treatment by analyzing the phosphorylation levels of checkpoint kinases CHK1 and CHK2 and histone H3, and by cell cycle profile analysis using flow cytometry. The radiosensitizing effect of garcinol was assessed by a clonogenic survival assay, whereas its effects on apoptosis and senescence were examined by annexin V and senescence-associated {beta}-galactosidase (SA-{beta}-Gal) staining, respectively. Results: We found that garcinol inhibits DSB repair, including NHEJ, without affecting cell cycle checkpoint. Garcinol radiosensitized A549 lung and HeLa cervical carcinoma cells with dose enhancement ratios (at 10% surviving fraction) of 1.6 and 1.5, respectively. Cellular senescence induced by IR was enhanced by garcinol. Conclusion: These results suggest that garcinol is a radiosensitizer that

  11. Post-irradiation DNA synthesis inhibition and G2 phase delay in radiosensitive body cells from non-Hodgkin's lymphoma patients: An indication of cell cycle defects

    International Nuclear Information System (INIS)

    Hannan, Mohammed A.; Kunhi, Mohammed; Einspenner, Michael; Khan, Bashir A.; Al-Sedairy, Sultan

    1994-01-01

    In the present study, both post-irradiation DNA synthesis and G 2 phase accumulation were analyzed in lymphoblastoid cell lines (LCLs) and fibroblast cell strains derived from (Saudi) patients with non-Hodgkin's lymphoma (NHL), ataxia telangiectasia (AT), AT heterozygotes and normal subjects. A comparison of the percent DNA synthesis inhibition (assayed by 3 H-thymidine uptake 30 min after irradiation), and a 24 h post-irradiation G 2 phase accumulation determined by flow cytometry placed the AT heterozygotes and the NHL patients in an intermediate position between the normal subjects (with maximum DNA synthesis inhibition and minimum G 2 phase accumulation) and the AT homozygotes (with minimum DNA synthesis inhibition and maximum G 2 accumulation). The similarity between AT heterozygotes and the NHL patients with respect to the two parameters studied after irradiation was statistically significant. The data indicating a moderate abnormality in the control of cell cycle progression after irradiation in the LCLs and fibroblasts from NHL patients may explain the enhanced cellular and chromosomal radiosensitivity in these patients reported by us earlier. In addition to demonstrating a link between cell cycle abnormality and radiosensitivity as a possible basis for cancer susceptibility, particularly in the NHL patients, the present studies emphasized the usefulness of the assay for 24 h post-irradiation G 2 phase accumulation developed elsewhere in characterizing AT heterozygote-like cell cycle anomaly in cancer patients irrespective of whether they carried the AT gene or any other affecting the cell cycle

  12. Radiation-induced damage to normal tissues after radiotherapy in patients treated for gynecologic tumors: Association with single nucleotide polymorphisms in XRCC1, XRCC3, and OGG1 genes and in vitro chromosomal radiosensitivity in lymphocytes

    International Nuclear Information System (INIS)

    Ruyck, Kim de; Eijkeren, Marc van; Claes, Kathleen; Morthier, Rudy; Paepe, Anne de; Vral, Anne; Ridder, Leo de; Thierens, Hubert

    2005-01-01

    Purpose: To examine the association of polymorphisms in XRCC1 (194Arg/Trp, 280Arg/His, 399Arg/Gln, 632Gln/Gln), XRCC3 (5' UTR 4.541A>G, IVS5-14 17.893A>G, 241Thr/Met), and OGG1 (326Ser/Cys) with the development of late radiotherapy (RT) reactions and to assess the correlation between in vitro chromosomal radiosensitivity and clinical radiosensitivity. Methods and Materials: Sixty-two women with cervical or endometrial cancer treated with RT were included in the study. According to the Common Terminology Criteria for Adverse Events, version 3.0, scale, 22 patients showed late adverse RT reactions. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assays were performed to examine polymorphic sites, the G2 assay was used to measure chromosomal radiosensitivity, and patient groups were compared using actuarial methods. Results: The XRCC3 IVS5-14 polymorphic allele was significantly associated with the risk of developing late RT reactions (odds ratio 3.98, p = 0.025), and the XRCC1 codon 194 variant showed a significant protective effect (p = 0.028). Patients with three or more risk alleles in XRCC1 and XRCC3 had a significantly increased risk of developing normal tissue reactions (odds ratio 10.10, p = 0.001). The mean number of chromatid breaks per cell was significantly greater in patients with normal tissue reactions than in patients with no reactions (1.16 and 1.34, respectively; p = 0.002). Patients with high chromosomal radiosensitivity showed a 9.2-fold greater annual risk of complications than patients with intermediate chromosomal radiosensitivity. Combining the G2 analysis with the risk allele model allowed us to identify 23% of the patients with late normal tissue reactions, without false-positive results. Conclusion: The results of the present study showed that clinical radiosensitivity is associated with an enhanced G2 chromosomal radiosensitivity and is significantly associated with a combination of different polymorphisms in

  13. Impacts of berberine on the growth, migration and radiosensitivity of breast cancer cells

    International Nuclear Information System (INIS)

    Zhao Chaoqian; Xu Jiaying; Jiao Yang; Hu Xudong; Che Jun; Fan Saijun

    2012-01-01

    Objective: To study the impacts of berberine on the growth, migration and radiosensitivity in human breast cancer cells. Methods: MTT assay was used to evaluate cell growth.In vitro scratch migration assay was used to determine cell migration. Annexin V assay was used to detect cell apoptosis. The distribution of cell cycle was evaluated by flow cytometry assay. Colony formation assay was used to detect the influence of berberine on cell radiosensitivity. Western blot assay was employed to measure protein expression. Results: Berberine inhibited cell growth and migration in two human breast cancer cell lines, MCF-7 and MDA-MB-231, in a dose-and time-dependent manner. Furthermore, berberine resulted in a cell cycle G 0 /G 1 arrest. Compared with control, the early apoptosis in MDA-MB-231 and MCF-7 cells treated with 40 pμmol/L of berberine was as high as 86.6% and 66.6% (t=8.79, 10.32, P<0.01), respectively. Berberine caused a dose-dependent increase in Bax and Caspase-3 protein expressions, but did not change Cyclin D1 protein expression, while suppressed the expressions of Cyclin B1 and Bcl-2 protein. As analyzed with multi-target click model fitting curves, the SER D0 of berberine-treated cells were 1.12 and 1.22 for MDA-MB-231 and MCF-7 cells respectively at the dose D 0 of X-rays. Conclusions: The berberine inhibited the growth and migration of breast cancer cells via apoptosis induction and cell cycle arrest. Moreover, berberine increases cell sensitivity to X-ray irradiation. (authors)

  14. Metformin radiosensitization effect of low and high linear energy transfer radiation in HCC

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Ho; Jung, Won Gyun [Division of Heavy Ion Clinical Research, Korea University, Seoul (Korea, Republic of); Kim, Mi Sook; Cho, Chul Koo; Jeong, Youn Kyoung [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2014-04-15

    Metformin (1,1-dimethylbiguanide hydrochloride), the most widely used treatment for type 2 diabetes, provides a good tolerability profile and low cost and has recently sparked keen interest as a potential anticancer agent. Recent evidence has suggested Metformin provides a synergistic benefit with chemotherapy or radiotherapy against certain cancers in several clinical cohort studies.Treatment response rates are higher in patients treated with metformin in cohort studies of breast cancer treated with neoadjuvant chemotherapy in head and neck cancer treated with radiation and in esophageal cancer treated with chemoradiotherapy. As the sensitizing effect of Metformin in HCC has been characterized in vitro and in vivo, we investigated the radio-sensitizing effect of Metformin in HCC cells in combination with γ-ray (low LET) and neutron (high LET) radiation. The radiosensitizing effect of Metformin was much higher in neutron-irradiated than in γ -irradiated cell lines. Fortunately, Metformin had little effect on normal tissues. Our studies revealed no interaction between Metformin and radiation in normal hepatocytes. High LET radiation,including neutron and carbon ion, would produce more complicated and different cellular effects; indeed, the molecular biological mechanism of high LET radiation remains a topic of investigation.

  15. Metformin radiosensitization effect of low and high linear energy transfer radiation in HCC

    International Nuclear Information System (INIS)

    Kim, Eun Ho; Jung, Won Gyun; Kim, Mi Sook; Cho, Chul Koo; Jeong, Youn Kyoung

    2014-01-01

    Metformin (1,1-dimethylbiguanide hydrochloride), the most widely used treatment for type 2 diabetes, provides a good tolerability profile and low cost and has recently sparked keen interest as a potential anticancer agent. Recent evidence has suggested Metformin provides a synergistic benefit with chemotherapy or radiotherapy against certain cancers in several clinical cohort studies.Treatment response rates are higher in patients treated with metformin in cohort studies of breast cancer treated with neoadjuvant chemotherapy in head and neck cancer treated with radiation and in esophageal cancer treated with chemoradiotherapy. As the sensitizing effect of Metformin in HCC has been characterized in vitro and in vivo, we investigated the radio-sensitizing effect of Metformin in HCC cells in combination with γ-ray (low LET) and neutron (high LET) radiation. The radiosensitizing effect of Metformin was much higher in neutron-irradiated than in γ -irradiated cell lines. Fortunately, Metformin had little effect on normal tissues. Our studies revealed no interaction between Metformin and radiation in normal hepatocytes. High LET radiation,including neutron and carbon ion, would produce more complicated and different cellular effects; indeed, the molecular biological mechanism of high LET radiation remains a topic of investigation

  16. Proteasome inhibitors block DNA repair and radiosensitize non-small cell lung cancer.

    Directory of Open Access Journals (Sweden)

    Kyle R Cron

    Full Text Available Despite optimal radiation therapy (RT, chemotherapy and/or surgery, a majority of patients with locally advanced non-small cell lung cancer (NSCLC fail treatment. To identify novel gene targets for improved tumor control, we performed whole genome RNAi screens to identify knockdowns that most reproducibly increase NSCLC cytotoxicity. These screens identified several proteasome subunits among top hits, including the topmost hit PSMA1, a component of the core 20 S proteasome. Radiation and proteasome inhibition showed synergistic effects. Proteasome inhibition resulted in an 80-90% decrease in homologous recombination (HR, a 50% decrease in expression of NF-κB-inducible HR genes BRCA1 and FANCD2, and a reduction of BRCA1, FANCD2 and RAD51 ionizing radiation-induced foci. IκBα RNAi knockdown rescued NSCLC radioresistance. Irradiation of mice with NCI-H460 xenografts after inducible PSMA1 shRNA knockdown markedly increased murine survival compared to either treatment alone. Proteasome inhibition is a promising strategy for NSCLC radiosensitization via inhibition of NF-κB-mediated expression of Fanconi Anemia/HR DNA repair genes.

  17. pSv3neo transfection and radiosensitivity of human cancer cell lines

    International Nuclear Information System (INIS)

    Parris, C.N.; Masters, J.R.W.; Green, M.H.L.

    1990-01-01

    Immortalisation of human fibroblasts by transfection with a plasmid, pSV3neo, results in an increase in their radioresistance. The change in radiosensitivity may either be a consequence of transformation or due to expression of the SV40 T-antigen in pSV3neo. To investigate these two possibilities, we transfected pSV3neo into cells already transformed and immortalised. The radiosensitivies of three human bladder cancer cell lines were unaltered in clones expressing T-antigen, indicating that the changes observed in fibroblasts probably are a consequence of transformation, and not the presence of SV40 T-antigen. (author)

  18. The enhancement of radiosensitivity by celecoxib, selective cyclooxygenase-2 inhibitor, on human cancer cells expressing differential levels of cyclooxygenase-2

    International Nuclear Information System (INIS)

    Pyo, Hong Ryull; Shin, You Keun; Kim, Hyun Seok; Seong, Jin Sil; Suh, Chang Ok; Kim, Gwi Eon

    2003-01-01

    To investigate the modulation of radiosensitivity by celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, on cancer cells over- and under-expressing COX-2. A clonogenic radiation survival analysis was performed on A549 human lung and MCF-7 human breast cancer cell lines incubated in both 1 and 10% fetal bovine serum (FBS) containing media. The apoptosis in both cell lines was measured after treatment with radiation and/or celecoxib. Celecoxib enhanced the radiation sensitivity of the A549 cells in the medium containing the 10% FBS, with radiation enhancement ratios of 1.58 and 1.81 respectively, at surviving fractions of 0.1, with 30 μ M and 50 μ M celecoxib. This enhanced radiosensitivity disappeared in the medium containing the 1% FBS. Celecoxib did not change the radiation sensitivity of the MCF-7 cells in either media. The induction of apoptosis by celecoxib and radiation was not synergistic in either cell line. Celecoxib, a selective COX-2 inhibitor, preferentially enhanced the effect of radiation on COX-2 over-expressing cancer cells compared to the cells with a low expression, and this effect disappeared on incubation of the cells during drug treatment in the medium with suboptimal serum concentration. Apoptosis did not appear to be the underlying mechanism of this radiation enhancement effect due to celecoxib on the A549 cells. These findings suggest radiosensitization by a selective COX-2 inhibitor is COX-2 dependent

  19. Hedgehog Pathway Inhibition Radiosensitizes Non-Small Cell Lung Cancers

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Jing; Aziz, Khaled; Chettiar, Sivarajan T. [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Aftab, Blake T. [Department of Medical Oncology, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Armour, Michael; Gajula, Rajendra; Gandhi, Nishant; Salih, Tarek; Herman, Joseph M.; Wong, John [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Rudin, Charles M. [Department of Medical Oncology, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Tran, Phuoc T. [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Department of Medical Oncology, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Hales, Russell K., E-mail: rhales1@jhmi.edu [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States)

    2013-05-01

    Purpose: Despite improvements in chemoradiation, local control remains a major clinical problem in locally advanced non-small cell lung cancer. The Hedgehog pathway has been implicated in tumor recurrence by promoting survival of tumorigenic precursors and through effects on tumor-associated stroma. Whether Hedgehog inhibition can affect radiation efficacy in vivo has not been reported. Methods and Materials: We evaluated the effects of a targeted Hedgehog inhibitor (HhAntag) and radiation on clonogenic survival of human non-small cell lung cancer lines in vitro. Using an A549 cell line xenograft model, we examined tumor growth, proliferation, apoptosis, and gene expression changes after concomitant HhAntag and radiation. In a transgenic mouse model of Kras{sup G12D}-induced and Twist1-induced lung adenocarcinoma, we assessed tumor response to radiation and HhAntag by serial micro-computed tomography (CT) scanning. Results: In 4 human lung cancer lines in vitro, HhAntag showed little or no effect on radiosensitivity. By contrast, in both the human tumor xenograft and murine inducible transgenic models, HhAntag enhanced radiation efficacy and delayed tumor growth. By use of the human xenograft model to differentiate tumor and stromal effects, mouse stromal cells, but not human tumor cells, showed significant and consistent downregulation of Hedgehog pathway gene expression. This was associated with increased tumor cell apoptosis. Conclusions: Targeted Hedgehog pathway inhibition can increase in vivo radiation efficacy in lung cancer preclinical models. This effect is associated with pathway suppression in tumor-associated stroma. These data support clinical testing of Hedgehog inhibitors as a component of multimodality therapy for locally advanced non-small cell lung cancer.

  20. Application of bio-marker to study on tumor radiosensitivity

    International Nuclear Information System (INIS)

    Guo Wanfeng; Ding Guirong; Han Liangfu

    2001-01-01

    To definite tumor radiosensitivity is important for applying the schedules of individualization of patient radiotherapy. Many laboratories were carrying on the research which predict the tumor radiosensitivity with one bio-marker or/and multi-bio-marker in various levels. At present has not witnessed the specific bio-marker, but it provides an excellent model for predicting tumor radiosensitivity

  1. New treatment strategy against advanced rectal cancer. Enzyme-targeting and radio-sensitization treatment under parallel use of TS-1

    International Nuclear Information System (INIS)

    Obata, Shiro; Yamanishi, Mikio; Katsumi, Shingo

    2015-01-01

    Preoperative chemoradiotherapy was applied to two cases of advanced rectal cancer. In addition, radiation sensitizers were injected to the lesion endoscopically at a pace of twice a week in order to enhance therapeutic effects (so-called enzyme-targeting and radio-sensitization treatment: KORTUC [Kochi Oxydol Radio-sensitization Treatment for Unresectable Carcinomas]). The flattening of the lesion shape was observed for both cases in a short period of time, then, Mile's and lateral lymphnode dissection was performed. The remnant of lesion was not pointed out in postoperative pathological specimens for both cases, and histological judgment after the treatment was ranked as Grade 3. In light of the better-than-expected results, this hospital is preparing for clinical trials, and planning to carefully accumulate the cases. As one of the curative treatment strategies against advanced rectal cancer, the authors are willing to make this KORTUC more objectively reliable as a safe and minimally invasive therapy. (A.O.)

  2. Effects of binding metronidazole to a copper-acetate compound on radiosensitizer properties

    International Nuclear Information System (INIS)

    Negron, Ana C. Valderrama; Silva, Denise de Oliveira; Cruz, Aurea S.

    2009-01-01

    Copper compounds exhibit interesting biological properties. Nitroimidazoles show radiosensitizer properties for radiotherapy tumor treatment. In the present work, the effect of binding metronidazole (1-(2-hydroxyethyl)-2-methyl-5-nitroimidazole = MTZ) to copper-acetate on the radiosensitizer properties has been investigated. A compound of copper-acetate-MTZ was prepared and characterized. The experiments were carried out by gamma-irradiation of Hep2 (human larynx cancer) cells under hypoxic conditions. The radiation doses for 50% cell survival in the presence of radiosensitizer were about 8.2 Gy for CuAcMTZ or free MTZ. The effect of binding metronidazole to copper acetate on radiosensitizer properties is mainly related to the radiosensitizer process which involves two events for CuAcMTZ in contrast to one event observed for the MTZ free drug. (author)

  3. Preferential radiosensitization of human prostatic carcinoma cells by mild hyperthermia

    International Nuclear Information System (INIS)

    Ryu, Samuel; Brown, Stephen L.; Kim, Sang-Hie; Khil, Mark S.; Kim, Jae Ho

    1996-01-01

    Purpose: Recent cell culture studies by us and others suggest that some human carcinoma cells are more sensitive to heat than are rodent cells following mild hyperthermia. In studying the cellular mechanism of enhanced thermosensitivity of human tumor cells to hyperthermia, prostatic carcinoma cells of human origin were found to be more sensitive to mild hyperthermia than other human cancer cells. The present study was designed to determine the magnitude of radiosensitization of human prostatic carcinoma cells by mild hyperthermia and to examine whether the thermal radiosensitization is related to the intrinsic thermosensitivity of cancer cells. Methods and Materials: Two human prostatic carcinoma cell lines (DU-145 and PC-3) and other carcinoma cells of human origin, in particular, colon (HT-29), breast (MCF-7), lung (A-549), and brain (U-251) were exposed to temperatures of 40-41 deg. C. Single acute dose rate radiation and fractionated radiation were combined with mild hyperthermia to determine thermal radiosensitization. The end point of the study was the colony-forming ability of single-plated cells. Results: DU-145 and PC-3 cells were found to be exceedingly thermosensitive to 41 deg. C for 24 h, relative to other cancer cell lines. Ninety percent of the prostatic cancer cells were killed by a 24 h heat exposure. Prostatic carcinoma cells exposed to a short duration of heating at 41 deg. C for 2 h resulted in a substantial enhancement of radiation-induced cytotoxicity. The thermal enhancement ratios (TERs) of single acute dose radiation following heat treatment 41 deg. C for 2 h were 2.0 in DU-145 cells and 1.4 in PC-3 cells. The TERs of fractionated irradiation combined with continuous heating at 40 deg. C were similarly in the range of 2.1 to 1.4 in prostate carcinoma cells. No significant radiosensitization was observed in MCF-7 and HT-29 cells under the same conditions. Conclusion: The present data suggest that a significant radiosensitization of

  4. Cell lines radiosensitization of thyroid cancer by histone deacetylase inhibitors

    International Nuclear Information System (INIS)

    Perona, M; Dagrosa, M A; Rossich, L; Casal, M; Pisarev, M A; Thomasz, L; Juvenal G J

    2012-01-01

    Introduction: Thyroid cancer is the most common endocrine neoplasia. Surgical resection and radioactive iodine is an effective treatment for well-differentiated tumors. Histone deacetylase inhibitors (HDAC-I) are agents that cause hyperacetylation of histone proteins and as a consequence remodeling of chromatin structure. They can induce growth arrest, differentiation and apoptotic cell death in different tumor cells. The use of HDAC-I agents could be of utility to enhance the response to external radiation therapy of those thyroid cancers that are refractory to most conventional therapeutic treatments. Objective: To study the effect of HDAC-I as radiosensitizers for the treatment of thyroid cancer and their ability to induce differentiation of thyroid cancer cells. Materials and methods: The human thyroid follicular (WRO) and papillary (TPC-1) carcinoma cell lines were seeded and incubated with increasing doses (0, 0.3, 0.5, 1 and 1.5 mM) of the HDAC-I sodium butirate (NaB) and valproic acid (VA) to evaluate cell proliferation and iodide uptake. Cells were irradiated with a 60 Co γ-ray source (1 ± 5% Gy/min) and postirradiation survival was quantified with the colony formation assay. Survival fraction at 2 Gy (SF2) was calculated for each cell line. Cell cycle and cell death were evaluated at a dose of 3 Gy. Iodide uptake, PCR analysis and transient transfection studies were performed. Results: Cell proliferation was not significantly suppressed after 24 hours of incubation with both drugs at all assayed doses. Iodide uptake was not modified after incubation with HDAC-I of both cell lines. SF2 was reduced from 68 ± 1.6 % in the control WRO cells to 42 ± 3.8 % (P<0.001) in NaB-treated cells. In TPC-1 SF2 was reduced from 32 ± 1.1 % in the control cells to 24 ± 0.8 % (P<0.01). In VA-treated cells SF2 was reduced from 69 ± 0.02 % in control WRO cells to 56 ± 0.01 % (P<0.01) and from 31 ± 2 % in control TPC-1 cells to 11 ± 1 % (P<0.01). There was an arrest

  5. Differential response of DU145 and PC3 prostate cancer cells to ionizing radiation: role of reactive oxygen species, GSH and Nrf2 in radiosensitivity.

    Science.gov (United States)

    Jayakumar, Sundarraj; Kunwar, Amit; Sandur, Santosh K; Pandey, Badri N; Chaubey, Ramesh C

    2014-01-01

    Radioresistance is the major impediment in radiotherapy of many cancers including prostate cancer, necessitating the need to understand the factors contributing to radioresistance in tumor cells. In the present study, the role of cellular redox and redox sensitive transcription factor, Nrf2 in the radiosensitivity of prostate cancer cell lines PC3 and DU145, has been investigated. Differential radiosensitivity of PC3 and DU145 cells was assessed using clonogenic assay, flow cytometry, and comet assay. Their redox status was measured using DCFDA and DHR probes. Expression of Nrf2 and its dependent genes was measured by EMSA and real time PCR. Knockdown studies were done using shRNA transfection. PC3 and DU145 cells differed significantly in their radiosensitivity as observed by clonogenic survival, apoptosis and neutral comet assays. Both basal and inducible levels of ROS were higher in PC3 cells than that of DU145 cells. DU145 cells showed higher level of basal GSH content and GSH/GSSG ratio than that of PC3 cells. Further, significant increase in both basal and induced levels of Nrf2 and its dependent genes was observed in DU145 cells. Knock-down experiments and pharmacological intervention studies revealed the involvement of Nrf2 in differential radio-resistance of these cells. Cellular redox status and Nrf2 levels play a causal role in radio-resistance of prostate cancer cells. The pivotal role Nrf2 has been shown in the radioresistance of tumor cells and this study will further help in exploiting this factor in radiosensitization of other tumor cell types. © 2013.

  6. MicroRNA-449a enhances radiosensitivity in CL1-0 lung adenocarcinoma cells.

    Directory of Open Access Journals (Sweden)

    Yi-Jyun Liu

    Full Text Available Lung cancer is the leading cause of cancer-related mortality worldwide. Radiotherapy is often applied for treating lung cancer, but it often fails because of the relative non-susceptibility of lung cancer cells to radiation. MicroRNAs (miRNAs have been reported to modulate the radiosensitivity of lung cancer cells and have the potential to improve the efficacy of radiotherapy. The purpose of this study was to identify a miRNA that can adjust radiosensitivity in lung adenocarcinoma cells. Two lung adenocarcinoma cell lines (CL1-0 and CL1-5 with different metastatic ability and radiosensitivity were used. In order to understand the regulatory mechanisms of differential radiosensitivity in these isogenic tumor cells, both CL1-0 and CL1-5 were treated with 10 Gy radiation, and were harvested respectively at 0, 1, 4, and 24 h after radiation exposure. The changes in expression of miRNA upon irradiation were examined using Illumina Human microRNA BeadChips. Twenty-six miRNAs were identified as having differential expression post-irradiation in CL1-0 or CL1-5 cells. Among these miRNAs, miR-449a, which was down-regulated in CL1-0 cells at 24 h after irradiation, was chosen for further investigation. Overexpression of miR-449a in CL1-0 cells effectively increased irradiation-induced DNA damage and apoptosis, altered the cell cycle distribution and eventually led to sensitization of CL1-0 to irradiation.

  7. Biomarkers of Tumour Radiosensitivity and Predicting Benefit from Radiotherapy.

    Science.gov (United States)

    Forker, L J; Choudhury, A; Kiltie, A E

    2015-10-01

    Radiotherapy is an essential component of treatment for more than half of newly diagnosed cancer patients. The response to radiotherapy varies widely between individuals and although advances in technology have allowed the adaptation of radiotherapy fields to tumour anatomy, it is still not possible to tailor radiotherapy based on tumour biology. A biomarker of intrinsic radiosensitivity would be extremely valuable for individual dosing, aiding decision making between radical treatment options and avoiding toxicity of neoadjuvant or adjuvant radiotherapy in those unlikely to benefit. This systematic review summarises the current evidence for biomarkers under investigation as predictors of radiotherapy benefit. Only 10 biomarkers were identified as having been evaluated for their radiotherapy-specific predictive value in over 100 patients in a clinical setting, highlighting that despite a rich literature there were few high-quality studies for inclusion. The most extensively studied radiotherapy predictive biomarkers were the radiosensitivity index and MRE11; however, neither has been evaluated in a randomised controlled trial. Although these biomarkers show promise, there is not enough evidence to justify their use in routine practice. Further validation is needed before biomarkers can fulfil their potential and predict treatment outcomes for large numbers of patients. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  8. Effect of Gamma Radiation on Amino Acid Based Vesicle Carrying Radiosensitizer

    International Nuclear Information System (INIS)

    Nur Ratasha Alia Mohd Rosli; Faizal Mohamed; Muhammad Amir Syafiq Mohd Sah; Irman Abdul Rahman

    2014-01-01

    Vesicles has been developed and studied to be used as a medium to transport radiosensitizer in treating cancer cells by increasing its sensitivity effectively towards the radiation given during radiotherapy. This study was conducted to investigate the effect of gamma radiation on amino acid-based vesicle carrying radiosensitizer. Amino acid based vesicles carrying radiosensitizer were synthesized using sonication method with sodium N-lauroylsarcosinate hydrate and decanol being the primary surfactant, while hydrogen peroxide and sodium hyaluronate as the encapsulated radiosensitizer. The synthesized vesicle was then irradiated at radiation doses equivalent to those given during radiotherapy. Irradiated vesicle carrying radiosensitizer were then characterized using Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR) and Polarized Light Microscope. Results obtained shows that there were no significant changes in morphology and molecular conformation of the synthesized vesicle after irradiation. Even at higher radiation dose of 100 Gray and 200 Gray, the results remained unchanged. This indicates that the synthesized vesicle carrying radiosensitizer is morphologically and spectroscopically stable even at high radiation doses. (author)

  9. WAF1 induction and infection by HPV E6 as a determinants of radiosensitivity in human cervical cancer

    Energy Technology Data Exchange (ETDEWEB)

    Harima, Yoko; Oka, Atsutoshi; Harima, Keizo; Tanaka, Yoshimasa [Kansai Medical Univ., Moriguchi, Osaka (Japan)

    1998-02-01

    To establish a new predictor of outcome for human cervical carcinoma treatment, the relationship between WAF1 mRNA levels during treatment, human papilloma virus (HPV) infection and tumor radiosensitivity were investigated. Forty patients with uterine cervical carcinoma were treated with definitive radiotherapy. Only those patients who beard wild-type p53 were included into present clinical trial. p53 status was investigated using SSCP analysis. HPV E6 was determined by PCR, WAF1 mRNA was estimated by RT-PCR. Twenty-one patients achieved complete response (CR), 11 patients achieved partial response (PR), and 8 patients had no change (NC). The increase in WAF1 mRNA after irradiation at 10.8 Gy positively correlated both with better treatment response and improved survival. Although the infection by HPV did not directly influence on the survival rate, it decreased the inducibility of WAF1. p53-dependent activation of WAF1 gene expression during treatment may be a strong determinant of the efficacy of cervical cancer radiotherapy. (author)

  10. WAF1 induction and infection by HPV E6 as a determinants of radiosensitivity in human cervical cancer

    International Nuclear Information System (INIS)

    Harima, Yoko; Oka, Atsutoshi; Harima, Keizo; Tanaka, Yoshimasa

    1998-01-01

    To establish a new predictor of outcome for human cervical carcinoma treatment, the relationship between WAF1 mRNA levels during treatment, human papilloma virus (HPV) infection and tumor radiosensitivity were investigated. Forty patients with uterine cervical carcinoma were treated with definitive radiotherapy. Only those patients who beard wild-type p53 were included into present clinical trial. p53 status was investigated using SSCP analysis. HPV E6 was determined by PCR, WAF1 mRNA was estimated by RT-PCR. Twenty-one patients achieved complete response (CR), 11 patients achieved partial response (PR), and 8 patients had no change (NC). The increase in WAF1 mRNA after irradiation at 10.8 Gy positively correlated both with better treatment response and improved survival. Although the infection by HPV did not directly influence on the survival rate, it decreased the inducibility of WAF1. p53-dependent activation of WAF1 gene expression during treatment may be a strong determinant of the efficacy of cervical cancer radiotherapy. (author)

  11. Increased radiosensitivity of a subpopulation of T-lymphocyte progenitors from patients with Fanconi's anemia

    International Nuclear Information System (INIS)

    Knox, S.; Wilson, F.D.; Greenberg, B.R.; Shifrime, M.; Rosenblatt, L.S.; Reeves, J.D.; Misra, H.P.

    1980-01-01

    In vitro radiation-survival of peripheral blood T-lymphocytes was studied in fifteen clinically normal adults and four patients with Fanconi's anemia (FA). Lymphocyte blastogenesis and cloning were measured following phytohemagglutinin (PHA) or Concanavalin-A (Con-A) stimulation. PHA-responsive lymphocytes from FA patients were significantly more radiosensitive than lymphocytes from normal individuals

  12. Increased Chromosomal Radiosensitivity in Women Carrying BRCA1/BRCA2 Mutations Assessed With the G2 Assay

    International Nuclear Information System (INIS)

    Ernestos, Beroukas; Nikolaos, Pandis; Koulis, Giannoukakos; Eleni, Rizou; Konstantinos, Beroukas; Alexandra, Giatromanolaki; Michael, Koukourakis

    2010-01-01

    Purpose: Several in vitro studies suggest that BRCA1 and BRCA2 mutation carriers present increased sensitivity to ionizing radiation. Different assays for the assessment of deoxyribonucleic acid double-strand break repair capacity have been used, but results are rather inconsistent. Given the concerns about the possible risks of breast screening with mammography in mutation carrier women and the potentially damaging effects of radiotherapy, the purpose of this study was to further investigate the radiosensitivity of this population. Methods and Materials: The G2 chromosomal radiosensitivity assay was used to assess chromosomal breaks in lymphocyte cultures after exposure to 1 Gy. A group of familiar breast cancer patients carrying a mutation in the BRCA1 or BRCA2 gene (n = 15) and a group of healthy mutation carriers (n = 5) were investigated and compared with a reference group of healthy women carrying no mutation (n = 21). Results: BRCA1 and BRCA2 mutation carriers had a significantly higher number of mean chromatid breaks per cell (p = 0.006) and a higher maximum number of breaks (p = 0.0001) as compared with their matched controls. Both healthy carriers and carriers with a cancer history were more radiosensitive than controls (p = 0.002 and p = 0.025, respectively). Age was not associated with increased radiosensitivity (p = 0.868). Conclusions: Our results indicate that BRCA1 and BRCA2 mutation carriers show enhanced radiosensitivity, presumably because of the involvement of the BRCA genes in deoxyribonucleic acid repair and cell cycle control mechanisms.

  13. Radiosensitivity of higher plants

    International Nuclear Information System (INIS)

    Feng Zhijie

    1992-11-01

    The general views on radiosensitivity of higher plants have been introduced from published references. The radiosensitivity varies with species, varieties and organs or tissues. The main factors of determining the radiosensitivity in different species are nucleus volume, chromosome volume, DNA content and endogenous compounds. The self-repair ability of DNA damage and chemical group of biological molecules, such as -SH thiohydroxy of proteins, are main factors to determine the radiosensitivity in different varieties. The moisture, oxygen, temperature radiosensitizer and protector are important external factors for radiosensitivity. Both the multiple target model and Chadwick-Leenhouts model are ideal mathematical models for describing the radiosensitivity of higher plants and the latter has more clear significance in biology

  14. Curcumin enhances the radiosensitivity of renal cancer cells by suppressing NF-κB signaling pathway.

    Science.gov (United States)

    Li, Gang; Wang, Ziming; Chong, Tie; Yang, Jie; Li, Hongliang; Chen, Haiwen

    2017-10-01

    The radiation resistance of renal cell carcinoma (RCC) remains the primary obstacle to improve patient survival. This study aimed to investigate the effects of curcumin on the radiosensitivity of RCC cells. Human RCC cell (ACHN) was exposed to irradiation (IR) and/or curcumin treatment. Cell viability, DNA repair, cell cycle, and apoptosis, were evaluated by MTT, immunofluoresence staining and flow cytometry. Moreover, ACHN cells were xenografted into nude mice and subjected to IR and/or curcumin treatment. The expression of NF-κB signaling related proteins in ACHN cells and xenografts was detected by western blot analysis. The results showed that curcumin significantly increased radiosensitivity of ACHN cells by inhibiting the cell proliferation and DNA damage repair, causing cell cycle arrest at G2/M phase, inducing apoptosis in vitro, and suppressing the growth of xenografts in vivo. In addition, curcumin enhanced radiosensitivity was through markedly inhibiting IR-induced NF-κB signaling by modulating the related protein expressions including NF-κBP65, I-κB, VEGF, COX2, and Bcl-2 in ACHN cells, which was further strengthened by NF-κB inhibitor PDTC treatment. Thus, curcumin may confer radiosensitivity on RCC via inhibition of NF-κB activation and its downstream regulars, suggesting the potential application of curcumin as an adjuvant in radiotherapy of RCC. Copyright © 2017. Published by Elsevier Masson SAS.

  15. Cytolethal Distending Toxin Enhances Radiosensitivity in Prostate Cancer Cells by Regulating Autophagy

    Directory of Open Access Journals (Sweden)

    Hwai-Jeng Lin

    2017-06-01

    Full Text Available Cytolethal distending toxin (CDT produced by Campylobacter jejuni contains three subunits: CdtA, CdtB, and CdtC. Among these three toxin subunits, CdtB is the toxic moiety of CDT with DNase I activity, resulting in DNA double-strand breaks (DSB and, consequently, cell cycle arrest at the G2/M stage and apoptosis. Radiation therapy is an effective modality for the treatment of localized prostate cancer (PCa. However, patients often develop radioresistance. Owing to its particular biochemical properties, we previously employed CdtB as a therapeutic agent for sensitizing radioresistant PCa cells to ionizing radiation (IR. In this study, we further demonstrated that CDT suppresses the IR-induced autophagy pathway in PCa cells by attenuating c-Myc expression and therefore sensitizes PCa cells to radiation. We further showed that CDT prevents the formation of autophagosomes via decreased high-mobility group box 1 (HMGB1 expression and the inhibition of acidic vesicular organelle (AVO formation, which are associated with enhanced radiosensitivity in PCa cells. The results of this study reveal the detailed mechanism of CDT for the treatment of radioresistant PCa.

  16. Overexpression of microRNA-132 enhances the radiosensitivity of cervical cancer cells by down-regulating Bmi-1.

    Science.gov (United States)

    Liu, Gui-Feng; Zhang, Shu-Hua; Li, Xue-Feng; Cao, Li-Yan; Fu, Zhan-Zhao; Yu, Shao-Nan

    2017-10-06

    We examined the effects of microRNA-132 (miR-132) on Bmi-1 expression and radiosensitivity in HeLa, SiHa, and C33A cervical cancer (CC) cells and 104 CC patients. MiR-132 expression was decreased and Bmi-1 expression was increased in tumor tissues compared to adjacent normal tissues and in radiotherapy-resistant patients compared to radiotherapy-sensitive patients. MiR-132 expression and Bmi-1 mRNA expression were also negatively correlated in tumor tissues. HeLa, SiHa, and C33A cells were divided into blank, miR-132 negative control (NC), miR-132 inhibitor, miR-132 mimics, siBmi-1, and miR-132 inhibitor + siBmi-1 groups, after which expression of miR-132 and Bmi-1, and the interaction between them and cell survival, proliferation, and apoptosis were examined. Bmi-1 was confirmed as a target of miRNA-132. Survival was higher and apoptosis lower in the miR-132 inhibitor group than the blank group after various doses of radiation. By contrast, survival was lower and apoptosis higher in the miRNA-132 mimics and siBmi-1 groups than in the blank group. Moreover, miR-132 expression increased and Bmi-1 mRNA expression decreased in each group at radiation doses of 6 and 8 Gy. Finally, co-administration of radiotherapy and exogenous miR-132 inhibited the growth of HeLa cell transplant-induced tumors in nude mice more effectively than radiotherapy alone. These results suggest overexpression of miR-132 enhances the radiosensitivity of CC cells by down-regulating Bmi-1 and that miR-132 may be a useful new target for the treatment of CC.

  17. Association of in vitro radiosensitivity and cancer in a family with acute myelogenous leukemia

    International Nuclear Information System (INIS)

    Bech-Hansen, N.T.; Sell, B.M.; Mulvihill, J.J.; Paterson, M.C.

    1981-01-01

    The gamma-ray sensitivity of skin fibroblasts from six members of a cancer family was investigated using a colony-forming assay. Fibroblasts from the three members with cancer (two sisters with acute myelogenous leukemia and the mother with cervical carcinoma) showed a significant (p less than 0.05) increase in radiosensitivity, while three members without cancer (the father and two sons) showed a normal radioresponse. The possibility that the increased gamma-ray sensitivity was due to defective DNA repair was investigated using assays for DNA repair replication, single-strand break rejoining, and removal of enzyme-sensitive sites in gamma-irradiated DNA. Results of these assays indicate that the kinetics of enzymatic repair of radiogenic DNA damage in general, and the rejoining of single-strand scissions and excision repair of base and sugar radioproducts in particular, were the same in the cell lines from the sensitive and clinically normal family members

  18. Association of in vitro radiosensitivity and cancer in a family with acute myelogenous leukemia

    International Nuclear Information System (INIS)

    Bech-Hansen, N.T.; Sell, B.M.; Mulvihill, J.J.; Paterson, M.C.

    1981-01-01

    The γ-ray sensitivity of skin fibroblasts from six members of a cancer family was investigated using a colony-forming assay. Fibroblasts from the three members with cancer (two sisters with acute myelogenous leukemia and the mother with cervical carcinoma) showed a significant ( p > 0.05) increase in radiosensitivity, while three members without cancer (the father and two sons) showed a normal radioresponse. The possiblity that the increased γ-ray sensitivity was due to defective DNA repair was investigated using assays for DNA repair replication, single-strand break rejoining, and removal of enzyme-sensitive sites in γ-irradiated DNA. Results of these assays indicate that the kinetics of enzymatic repair of radiogenic DNA damage in general, and the rejoining of single-strand scissions and excision repair of base and sugar radioproducts in partigular, were the same in the cell lines from the sensitive and clinically normal family members

  19. Evaluation of Radiosensitivity of HeLa Cells Infected with Polio Virus Irradiated by Co 60

    Directory of Open Access Journals (Sweden)

    F Seif

    2008-04-01

    Full Text Available ABSTRACT: Introduction & Objective: The main purpose of radiotherapy is exposing enough doses of radiation to tumor tissue and protecting the normal tissues around it. Tumor dose for each session in radiotherapy will be considered based on radiosensitivity of the tissues. The presence of viral diseases in tumoral area can affect the radiosensitivity of cells. This study aimed to evaluate the radiosensitivity of Hela cells infected with poliomyelitis virus irradiated by Co 60. Materials & Methods: In this study, the radiosensitivity of HeLa cells, with or without the viral infection, after gamma radiation of cobalt 60, was assessed. Results: Results of comparison of the radisensitivity of infected and uninfected cells indicates that after 2 Gy irradiation by Co 60, polio infection in low, moderate and high virus load, increases the cell death by 20-30%, 30-40% and 70-90% respectively. Conclusion : Radiosensitivity of tumoral cells increase when they are infected with viral agents. Results of this study showed that non cancer diseases should be considered when prescribing dose fraction in radiotherapy of cancers.

  20. Radiosensitization of human endothelial cells by IL-24

    International Nuclear Information System (INIS)

    Meyn, R.E.

    2003-01-01

    Radiation therapy remains an important cancer treatment modality but despite improvements in dose delivery many patients still fail at their primary tumor site. Therefore, new strategies designed to improve local control are needed. Protocols combining radiation with anti-angiogenic agents might be of particular advantage based on their documented low toxicity. In this regard, we have been conducting preclinical investigations of a novel cytokine, mda7/IL-24. Our collaborators have shown that mda7/IL-24 protein targets the endothelial cells of the tumor microvascular system and has potent anti-angiogenic properties in both in vitro and in vivo assays. Recently, we have demonstrated that recombinant mda7/IL-24 protein radiosensitizes human endothelial cells in vitro. Specifically, 10 ng/ml of recombinant human IL-24 protein for 12 hrs reduced the survival at 2 Gy for human umbilical vein endothelial cells (HUVECs) from 0.33 to 0.12. We are also working on understanding the molecular basis for this radiosensitizing effect. Preliminary data suggest a model whereby mda7/IL-24 engages a specific receptor on the surface of endothelial cells and initiates a signal transduction pathway that modulates the cell's propensity for radiation-induced apoptosis and capacity for repairing radiation-induced DNA double strand breaks. Mechanistic insight gained from these studies may have implications for the actions of other anti-angiogenic agents and may generally explain the regulation of radiosensitivity imparted by growth factors and cytokines

  1. TAS-116, a novel Hsp90 inhibitor, selectively enhances radio-sensitivity of human cancer cells to X-rays and carbon ion radiation

    Science.gov (United States)

    Lee, Younghyun; Sunada, Shigeaki; Hirakawa, Hirokazu; Fujimori, Akira; Nickoloff, Jac A.; Okayasu, Ryuichi

    2016-01-01

    Hsp90 inhibitors have been investigated as cancer therapeutics in mono-therapy and to augment radiotherapy, however serious adverse effects of early generation Hsp90 inhibitors limited their development. TAS-116 is a novel Hsp90 inhibitor with lower adverse effects than other Hsp90 inhibitors, and here we investigated the radio-sensitizing effects of TAS-116 in low LET X-ray, and high LET carbon ion irradiated human cancer cells and mouse tumor xenografts. TAS-116 decreased cell survival of both X-ray and carbon ion-irradiated human cancer cell lines (HeLa and H1299 cells), and similar to other Hsp90 inhibitors, it did not affect radiosensitivity of non-cancerous human fibroblasts. TAS-116 increased the number of radiation-induced γ-H2AX foci, and delayed the repair of DNA double-strand breaks (DSBs). TAS-116 reduced the expression of proteins that mediate repair of DSBs by homologous recombination (RAD51) and non-homologous end joining (Ku, DNA-PKcs), and suppressed formation of RAD51 foci and phosphorylation/activation of DNA-PKcs. TAS-116 also decreased expression of the cdc25 cell cycle progression marker, markedly increasing G2/M arrest. Combined treatment of mouse tumor xenografts with carbon ions and TAS-116 showed promising delay in tumor growth compared to either individual treatment. These results demonstrate that TAS-116 radio-sensitizes human cancer cells to both X rays and carbon ions by inhibiting the two major DSB repair pathways, and these effects were accompanied by marked cell cycle arrest. The promising results of combination TAS-116 + carbon ion radiation therapy of tumor xenografts justify further exploration of TAS-116 as an adjunct to radiotherapy using low or high LET radiation. PMID:28062703

  2. Differential Radiosensitizing Effect of Valproic Acid in Differentiation Versus Self-Renewal Promoting Culture Conditions

    International Nuclear Information System (INIS)

    Debeb, Bisrat G.; Xu Wei; Mok, Henry; Li Li; Robertson, Fredika; Ueno, Naoto T.; Reuben, Jim; Lucci, Anthony; Cristofanilli, Massimo; Woodward, Wendy A.

    2010-01-01

    Purpose: It has been shown that valproic acid (VA) enhances the proliferation and self-renewal of normal hematopoietic stem cells and that breast cancer stem/progenitor cells can be resistant to radiation. From these data, we hypothesized that VA would fail to radiosensitize breast cancer stem/progenitor cells grown to three-dimensional (3D) mammospheres. Methods and Materials: We used the MCF7 breast cancer cell line grown under stem cell-promoting culture conditions (3D mammosphere) and standard nonstem cell monolayer culture conditions (two-dimensional) to examine the effect of pretreatment with VA on radiation sensitivity in clonogenic survival assays and on the expression of embryonic stem cell transcription factors. Results: 3D-cultured MCF-7 cells expressed higher levels of Oct4, Nanog, and Sox2. The 3D passage enriched self-renewal and increased radioresistance in the 3D mammosphere formation assays. VA radiosensitized adherent cells but radioprotected 3D cells in single-fraction clonogenic assays. Moreover, fractionated radiation sensitized VA-treated adherent MCF7 cells but did not have a significant effect on VA-treated single cells grown to mammospheres. Conclusion: We have concluded that VA might preferentially radiosensitize differentiated cells compared with those expressing stem cell surrogates and that stem cell-promoting culture is a useful tool for in vitro evaluation of novel cancer therapeutic agents and radiosensitizers.

  3. EGFR inhibitor C225 increases the radiosensitivity of human lung squamous cancer cells

    Directory of Open Access Journals (Sweden)

    Yang Ruijie

    2010-10-01

    Full Text Available Abstract Background The purpose of the present study is to investigate the direct biological effects of the epidermal growth factor receptor (EGFR inhibitor C225 on the radiosensitivity of human lung squamous cancer cell-H520. H520 cells were treated with different dosage of 60Co γ ray irradiation (1.953 Gy/min in the presence or absence of C225. The cellular proliferation, colony forming capacity, apoptosis, the cell cycle distribution as well as caspase-3 were analyzed in vitro. Results We found that C225 treatment significantly increased radiosensitivity of H-520 cells to irradiation, and led to cell cycle arrest in G1 phase, whereas 60Co γ ray irradiation mainly caused G2 phase arrest. H-520 cells thus displayed both the G1 and G2 phase arrest upon treatment with C225 in combination with 60Co γ ray irradiation. Moreover, C225 treatment significantly increased the apoptosis percentage of H-520 cells (13.91% ± 1.88% compared with the control group (5.75% ± 0.64%, P Conclusion In this regard, C225 treatment may make H-520 cells more sensitive to irradiation through the enhancement of caspase-3 mediated tumor cell apoptosis and cell cycle arrest.

  4. Effect of sanguinarine on the growth and radiosensitivity of human ovarian cancer cells

    International Nuclear Information System (INIS)

    Xu Jiaying; Ji Junmin; Jiao Yang; Wu Li; Fan Sanjun

    2012-01-01

    Objective: To study the effect of sanguinarine on the growth and radiosensitivity of ovarian cancer SK-OV-3 cells. Methods: Cell growth was determined by MTT and clonogenic assay. Cell cycle analysis was performed by flow cytometry assay. The cell apoptosis was analyzed by Annexin V/PI assay. Results: Sanguinarine inhibited SK-OV-3 cell growth in a dose-and time-dependent fashion and its IC 50 values were 3.02 and 1.11 μmol/L at 24 and 48 h, respectively. Sanguinarine also significantly triggered a sub-G 1 peak, an indicator of apoptosis,and caused a G 0 /G 1 arrest. Furthermore, the cell apoptosis induced by X-irradiation was significantly increased at 6 Gy when the cells were pre-treated with sanguinarine, in which the early apoptotic population increased from 10.28% to 43.28% (t=19.41, P<0.01) and the late apoptotic population increased from 20.26% to 30.80% (t=8.78, P<0.01). The multi-target click model was used to fit survival curves and the SER of sanguinarine treatment approached to 1.625 at the dose of D 0 . Conclusions: Sanguinarine could inhibit SK-OV-3 cell growth by inducing apoptosis and cell cycle arrest and enhance cell radiosensitivity at low doses. (authors)

  5. Radio-sensitization of esophageal cancer EC9706 cells to X ray by histone deacetylase inhibiter Trichostatin A

    International Nuclear Information System (INIS)

    Lin Xiaoli; Qin Guangyong; Fang Huasheng; Zhang Fengqiu; Ya Huiyuan

    2009-01-01

    Cell apoptosis and the expression of DNA damage repair-related genes XRCC2, ATM and Lig4 were detected separately by flow cytometry analysis and real-time fluorescence quantitative (RT-PCR), in order to investigate the effect of Trichostatin A (TSA) pre-treatment on the radiosensitivity of esophageal cancer EC9706 cells to X ray in vitro. The results indicate that pre-irradiation exposure to TSA enhances cell apoptotic rate by X ray markedly (P<0.05) and the mRNA levels of XRCC2, ATM and Lig4 (except 8Gy) are up-regulated by X ray individually (P<0.05). TSA alone and TSA in combination with X ray all reduce mRNA levels of XRCC2, ATM and Lig4. In conclusions, TSA may radio-sensitize EC9706 cells to X ray by reducing mRNA levels of XRCC2, ATM and Lig4. (authors)

  6. DNA-Dependent Protein Kinase As Molecular Target for Radiosensitization of Neuroblastoma Cells.

    Science.gov (United States)

    Dolman, M Emmy M; van der Ploeg, Ida; Koster, Jan; Bate-Eya, Laurel Tabe; Versteeg, Rogier; Caron, Huib N; Molenaar, Jan J

    2015-01-01

    Tumor cells might resist therapy with ionizing radiation (IR) by non-homologous end-joining (NHEJ) of IR-induced double-strand breaks. One of the key players in NHEJ is DNA-dependent protein kinase (DNA-PK). The catalytic subunit of DNA-PK, i.e. DNA-PKcs, can be inhibited with the small-molecule inhibitor NU7026. In the current study, the in vitro potential of NU7026 to radiosensitize neuroblastoma cells was investigated. DNA-PKcs is encoded by the PRKDC (protein kinase, DNA-activated, catalytic polypeptide) gene. We showed that PRKDC levels were enhanced in neuroblastoma patients and correlated with a more advanced tumor stage and poor prognosis, making DNA-PKcs an interesting target for radiosensitization of neuroblastoma tumors. Optimal dose finding for combination treatment with NU7026 and IR was performed using NGP cells. One hour pre-treatment with 10 μM NU7026 synergistically sensitized NGP cells to 0.63 Gy IR. Radiosensitizing effects of NU7026 increased in time, with maximum effects observed from 96 h after IR-exposure on. Combined treatment of NGP cells with 10 μM NU7026 and 0.63 Gy IR resulted in apoptosis, while no apoptotic response was observed for either of the therapies alone. Inhibition of IR-induced DNA-PK activation by NU7026 confirmed the capability of NGP cells to, at least partially, resist IR by NHEJ. NU7026 also synergistically radiosensitized other neuroblastoma cell lines, while no synergistic effect was observed for low DNA-PKcs-expressing non-cancerous fibroblasts. Results obtained for NU7026 were confirmed by PRKDC knockdown in NGP cells. Taken together, the current study shows that DNA-PKcs is a promising target for neuroblastoma radiosensitization.

  7. The study on the effect of artesunate on the radio-sensitivity of human cervical cancer

    International Nuclear Information System (INIS)

    Geng Chong; Cao Jianping; Ni Qianying

    2011-01-01

    To investigate the effect of artesunate on radio-sensitivity of human cervical cancer cells in vitro. The human cervical cancer cells HeLa and Siha were used as the experimental cells. MTT assay was used to determine the most appropriate drug concentration in the subsequent experiment, and the effect of human cervical cancer cells treated with artesunate and irradiation of 60 Co γ-rays was studied by using conventional chromosomal aberration analysis and cytokinesis block method (CB method). The results show that when the concentration of artesunate in this experiment was 2.0 μmol/L for HeLa cell and 4.0 μmol/L for Siha cell respectively, the chromosome aberration, micronuclei cell and micronuclei rates of HeLa cells treated with artesunate were more serious than that of the only irradiation, but there is almost no change with Siha cells. (authors)

  8. Radiosensitivity of hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Hennequin, C.; Quero, L.; Rivera, S.

    2011-01-01

    The frequency of hepatocellular carcinoma (HCC) is increasing in the western world and the role of radiotherapy is more and more discussed. Classically, hepatocellular carcinoma was considered as a radioresistant tumour: in fact, modern radio-biologic studies, performed on cell lines directly established from patients, showed that hepatocellular carcinoma has the same radiosensitivity than the other epithelial tumours. From clinical studies, its α/β ratio has been estimated to be around 15 Gy. Radiosensitivity of normal hepatic parenchyma is now well evaluated and some accurate NTCP models are available to guide hepatic irradiation. The biology of hepatocellular carcinoma is also better described: the combination of radiotherapy and targeted therapies will be a promising approach in the near future. (authors)

  9. Curcumin and trans-resveratrol exert cell cycle-dependent radioprotective or radiosensitizing effects as elucidated by the PCC and G2-assay

    Energy Technology Data Exchange (ETDEWEB)

    Sebastià, N., E-mail: natividad.sebastia@uv.es [Radiation Protection Service, IIS La Fe, Health Research Institute La Fe, Valencia (Spain); Montoro, A. [Radiation Protection Service, Universitary and Politechnic Hospital La Fe, Valencia (Spain); Grupo de Investigación Biomédica en Imagen GIBI230, IIS La Fe, Health Research Institute La Fe, Valencia (Spain); Unidad Mixta de Investigación en Endocrinología, Nutrición y Dietética Clínica, IIS La Fe, Health Research Institute La Fe, Valencia (Spain); Hervás, D. [Biostatistics Unit, IIS La Fe, Health Research Institute La Fe, Valencia (Spain); Pantelias, G.; Hatzi, V.I. [Institute of Nuclear and Radiological Sciences and Technology, Energy and Safety, National Centre for Scientific Research “Demokritos”, Aghia Paraskevi, Athens (Greece); Soriano, J.M. [Grupo de Investigación Biomédica en Imagen GIBI230, IIS La Fe, Health Research Institute La Fe, Valencia (Spain); Unidad Mixta de Investigación en Endocrinología, Nutrición y Dietética Clínica, IIS La Fe, Health Research Institute La Fe, Valencia (Spain); Department of Preventive Medicine and Public Health, Faculty of Pharmacy, University of Valencia, Burjassot, Valencia (Spain); Villaescusa, J.I. [Radiation Protection Service, Universitary and Politechnic Hospital La Fe, Valencia (Spain); and others

    2014-08-15

    testing, which simulates conditions similar to those of the highly radiosensitive lymphocytes of AT patients. The results demonstrate for the first time the cell-cycle-dependent action of these polyphenols. When non-cycling cells are irradiated, the radioprotective properties of curcumin and trans-resveratrol are more prominent. However, when cycling cells are irradiated during G2-phase, the radiosensitizing features of these compounds are more pronounced. This observation offers a new biological basis for the mechanisms underlying the action of these polyphenols in cancer radiotherapy.

  10. Curcumin and trans-resveratrol exert cell cycle-dependent radioprotective or radiosensitizing effects as elucidated by the PCC and G2-assay

    International Nuclear Information System (INIS)

    Sebastià, N.; Montoro, A.; Hervás, D.; Pantelias, G.; Hatzi, V.I.; Soriano, J.M.; Villaescusa, J.I.

    2014-01-01

    testing, which simulates conditions similar to those of the highly radiosensitive lymphocytes of AT patients. The results demonstrate for the first time the cell-cycle-dependent action of these polyphenols. When non-cycling cells are irradiated, the radioprotective properties of curcumin and trans-resveratrol are more prominent. However, when cycling cells are irradiated during G2-phase, the radiosensitizing features of these compounds are more pronounced. This observation offers a new biological basis for the mechanisms underlying the action of these polyphenols in cancer radiotherapy

  11. Mitochondrial modulation of oxygen-dependent radiosensitivity in some human tumour cell lines.

    LENUS (Irish Health Repository)

    Anoopkumar-Dukie, S

    2009-10-01

    Oxygen-dependent radiosensitivity of tumour cells reflects direct oxidative damage to DNA, but non-nuclear mechanisms including signalling pathways may also contribute. Mitochondria are likely candidates because not only do they integrate signals from each of the main kinase pathways but mitochondrial kinases responsive to oxidative stress communicate to the rest of the cell. Using pharmacological and immunochemical methods, we tested the role of mitochondrial permeability transition (MPT) and the Bcl-2 proteins in oxygen-dependent radiosensitivity. Drug-treated or untreated cervical cancer HeLa, breast cancer MCF-7 and melanoma MeWo cell lines were irradiated at 6.2 Gy under normoxic and hypoxic conditions then allowed to proliferate for 7 days. The MPT blocker cyclosporin A (2 microM) strongly protected HeLa but not the other two lines against oxygen-dependent radiosensitivity. By contrast, bongkrekic acid (50 microM), which blocks MPT by targeting the adenine nucleotide transporter, had only marginal effect and calcineurin inhibitor FK-506 (0.1 microM) had none. Nor was evidence found for the modulation of oxygen-dependent radiosensitivity by Bax\\/Bcl-2 signalling, mitochondrial ATP-dependent potassium (mitoK(ATP)) channels or mitochondrial Ca(2+) uptake. In conclusion, calcineurin-independent protection by cyclosporin A suggests that MPT but not mitoK(ATP) or the mitochondrial apoptosis pathway plays a causal role in oxygen-dependent radiosensitivity of HeLa cells. Targeting MPT may therefore improve the effectiveness of radiotherapy in some solid tumours.

  12. Environmental and genetic interactions in human cancer

    International Nuclear Information System (INIS)

    Paterson, M.C.

    Humans, depending upon their genetic make-up, differ in their susceptibility to the cancer-causing effects of extrinsic agents. Clinical and laboratory studies on the hereditary disorder, ataxia telangiectasia (AT) show that persons afflicted with this are cancer-prone and unusually sensitive to conventional radiotherapy. Their skin cells, when cultured, are hypersensitive to killing by ionizing radiation, being defective in the enzymatic repair of radiation-induced damange to the genetic material, deoxyribonucleic acid (DNA). This molecular finding implicates DNA damage and its imperfect repair as an early step in the induction of human cancer by radiation and other carcinogens. The parents of AT patients are clincally normal but their cultured cells are often moderately radiosensitive. The increased radiosensitivity of cultured cells offers a means of identifying a presumed cancer-prone subpopulation that should avoid undue exposure to certain carcinogens. The radioresponse of cells from patients with other cancer-associated genetic disorders and persons suspected of being genetically predisposed to radiation-induced cancer has also been measured. Increased cell killing by γ-rays appears in the complex genetic disease, tuberous sclerosis. Cells from cancer-stricken members of a leukemia-prone family are also radiosensitive, as are cells from one patient with radiation-associated breast cancer. These radiobiological data, taken together, strongly suggest that genetic factors can interact with extrinsic agents and thereby play a greater causative role in the development of common cancers in man than previously thought. (L.L.)

  13. Down-regulation of LncRNA TUG1 enhances radiosensitivity in bladder cancer via suppressing HMGB1 expression.

    Science.gov (United States)

    Jiang, Huijuan; Hu, Xigang; Zhang, Hongzhi; Li, Wenbo

    2017-04-04

    Long non-coding RNAs (lncRNAs) have been reported to regulate the sensitivity of different cancer cells to chemoradiotherapy. Aberrant expression of lncRNA Taurine-upregulated gene 1 (TUG1) has been found to be involved in the development of bladder cancer, however, its function and underlying mechanism in the radioresistance of bladder cancer remains unclear. Quantitative real-time PCR (qRT-PCR) was conducted to measure the expression of TUG1 and HMGB1 mRNA in bladder cancer tissues and cell lines. HMGB1 protein levels were tested by western blot assays. Different doses of X-ray were used for radiation treatment of bladder cancer cells. Colony survival and cell viability were detected by clonogenic assay and CCK-8 Kit, respectively. Cell apoptosis was determined by flow cytometry. A xenograft mouse model was constructed to observe the effect of TUG1 on tumor growth in vivo. The levels of TUG1 and HMGB1 were remarkably increased in bladder cancer tissues and cell lines. Radiation treatment markedly elevated the expression of TUG1 and HMGB1. TUG1 knockdown inhibited cell proliferation, promoted cell apoptosis and decreased colony survival in SW780 and BIU87 cells under radiation. Moreover, TUG1 depletion suppressed the HMGB1 mRNA and protein levels. Furthermore, overexpression of HMGB1 reversed TUG1 knockdown-induced effect in bladder cancer cells. Radiation treatment dramatically reduced the tumor volume and weight in xenograft model, and this effect was more obvious when combined with TUG1 silencing. LncRNA TUG1 knockdown enhances radiosensitivity of bladder cancer by suppressing HMGB1 expression. TUG1 acts as a potential regulator of radioresistance of bladder cancer, and it may represent a promising therapeutic target for bladder cancer patients.

  14. Potential clinical impact of normal-tissue intrinsic radiosensitivity testing

    International Nuclear Information System (INIS)

    Bentzen, Soeren M.

    1997-01-01

    A critical appraisal is given of the possible benefit from a reliable pre-treatment knowledge of individual normal-tissue sensitivity to radiotherapy. The considerations are in part, but not exclusively, based on the recent experience with in vitro colony-forming assays of the surviving fraction at 2 Gy, the SF 2 . Three strategies are reviewed: (1) to screen for rare cases with extreme radiosensitivity, so-called over-reactors, and treat these with reduced total dose, (2) to identify the sensitive tail of the distribution of 'normal' radiosensitivities, refer these patients to other treatment, and to escalate the dose to the remaining patients, or (3) to individualize dose prescriptions based on individual radiosensitivity, i.e. treating to isoeffect rather than to a specific dose-fractionation schedule. It is shown that these strategies will have a small, if any, impact on routine radiotherapy. Screening for over-reactors is hampered by the low prevalence of these among otherwise un-selected patients that leads to a low positive predictive value of in vitro radiosensitivity assays. It is argued, that this problem may persist even if the noise on current assays could be reduced to (the unrealistic value of) zero, simply because of the large biological variation in SF 2 . Removing the sensitive tail of the patient population, will only have a minor effect on the dose that could be delivered to the remaining patients, because of the sigmoid shape of empirical dose-response relationships. Finally, individualizing dose prescriptions based exclusively on information from a normal-tissue radiosensitivity assay, leads to a nearly symmetrical distribution of dose-changes that would produce a very small gain, or even a loss, of tumor control probability if implemented in the clinic. From a theoretical point of view, other strategies could be devised and some of these are considered in this review. Right now the most promising clinical use of in vitro radiosensitivity

  15. The combination of olaparib and camptothecin for effective radiosensitization

    International Nuclear Information System (INIS)

    Miura, Katsutoshi; Sakata, Koh-ichi; Someya, Masanori; Matsumoto, Yoshihisa; Matsumoto, Hideki; Takahashi, Akihisa; Hareyama, Masato

    2012-01-01

    Poly (ADP-ribose) polymerase-1 (PARP-1) is a key enzyme involved in the repair of radiation-induced single-strand DNA breaks. PARP inhibitors such as olaparib (KU-0059436, AZD-2281) enhance tumor sensitivity to radiation and to topoisomerase I inhibitors like camptothecin (CPT). Olaparib is an orally bioavailable inhibitor of PARP-1 and PARP-2 that has been tested in multiple clinical trials. The purpose of this study was to investigate the characteristics of the sensitizing effect of olaparib for radiation and CPT in order to support clinical application of this agent. DLD-1 cells (a human colorectal cancer cell line) and H1299 cells (a non-small cell lung cancer cell line) with differences of p53 gene status were used. The survival of these cells was determined by clonogenic assay after treatment with drugs and X-ray irradiation. The γH2AX focus formation assay was performed to examine the influence of olaparib on induction and repair of double-stranded DNA breaks after exposure to radiation or CPT. A radiosensitizing effect of olaparib was seen even at 0.01 μM. Its radiosensitizing effect after exposure for 2 h was similar to that after 24 h. H1299 cells with depletion or mutation of p53 were more radioresistant than H1299 cells with wild-type p53. However, similar enhancement of radiosensitization by olaparib was observed with all of the tested cell lines regardless of the p53 status. Olaparib also sensitized cells to CPT. This sensitizing effect was seen at low concentrations of olaparib such as 0.01 μM, and its sensitizing effect was the same at both 0.01 μM and 1 μM. The combination of olaparib and CPT had a stronger radiosensitizing effect. The results of the γH2AX focus assay corresponded with the clonogenic assay findings. Olaparib enhanced sensitivity to radiation and CPT at low concentrations and after relatively short exposure times such as 2 h. The radiosensitizing effect of olaprib was not dependent on the p53 status of tumor cells. These

  16. Superiority of Low Energy 160 KV X-Rays Compared to High Energy 6 MV X-Rays in Heavy Element Radiosensitization for Cancer Treatment

    Science.gov (United States)

    Lim, Sara N.; Pradhan, Anil K.; Nahar, Sultana N.; Barth, Rolf F.; Yang, Weilian; Nakkula, Robin J.; Palmer, Alycia; Turro, Claudia

    2013-06-01

    High energy X-rays in the MeV range are generally employed in conventional radiation therapy from linear accelerators (LINAC) to ensure sufficient penetration depths. However, lower energy X-rays in the keV range may be more effective when coupled with heavy element (high-Z or HZ) radiosensitizers. Numerical simulations of X-ray energy deposition for tumor phantoms sensitized with HZ radiosensitizers were performed using the Monte Carlo code Geant4. The results showed enhancement in energy deposition to radiosensitized phantoms relative to unsensitized phantoms for low energy X-rays in the keV range. In contrast, minimal enhancement was seen using high energy X-rays in the MeV range. Dose enhancement factors (DEFs) were computed and showed radiosensitization only in the low energy range nitrate, was initially used because it was 7x less toxic that an equivalent amount of carboplatin in vitro studies. This would allow us to separate the radiotoxic and the chemotoxic effects of HZ sensitizers. Results from this study showed a 10-fold dose dependent reduction in surviving fractions (SF) of radiosensitized cells treated with low energy 160 kV X-rays compared to those treated with 6 MV X-rays. This is in agreement with our simulations that show an increase in dose deposition in radiosensitized tumors for low energy X-rays. Due to unforeen in vivo toxicity, however, another in vitro study was performed using the commonly used, Pt-based chemotherapeutic drug carboplatin which confirmed earlier results. This lays the ground work for a planned in vivo study using F98 glioma bearing rats. This study demonstrates that while high energy X-rays are commonly used in cancer radiotherapy, low energy keV X-rays might be much more effective with HZ radiosensitization.

  17. Radiosensitizing effect of epothilone B on human epithelial cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Baumgart, T.; Kriesen, S.; Hildebrandt, G.; Manda, K. [Univ. of Rostock (Germany). Dept. of Radiotherapy and Radiation Oncology; Klautke, G.; Fietkau, R. [Friedrich-Alexander-Univ. Erlangen-Nuernberg, Erlangen (Germany). Dept. of Radiation Oncology; Kuznetsov, S.A.; Weiss, D.G. [Univ. of Rostock (Germany). Inst. of Biological Sciences, Cell Biology, and Biosystems Technology

    2012-02-15

    A combined modality treatment employing radiation and chemotherapy plays a central role in the management of solid tumors. In our study, we examined the cytotoxic and radiosensitive effect of the microtubule stabilizer epothilone B on two human epithelial tumor cell lines in vitro and its influence on the microtubule assembly. Cancer cells were treated with epothilone B in proliferation assays and in combination with radiation in colony-forming assays. For the analysis of ionizing radiation-induced DNA damage and the influence of the drug on its repair a {gamma}H2AX foci assay was used. To determine the effect of epothilone B on the microtubule assembly in cells and on purified tubulin, immunofluorescence staining and tubulin polymerization assay, respectively, were conducted. Epothilone B induced a concentration- and application-dependent antiproliferative effect on the cells, with IC{sub 50} values in the low nanomolar range. Colony forming assays showed a synergistic radiosensitive effect on both cell lines which was dependent on incubation time and applied concentration of epothilone B. The {gamma}H2AX assays demonstrated that ionizing radiation combined with the drug resulted in a concentration-dependent increase in the number of double-strand breaks and suggested a reduction in DNA repair capacity. Epothilone B produced enhanced microtubule bundling and abnormal spindle formation as revealed by immunofluorescence microscopy and caused microtubule formation from purified tubulin. The results of this study showed that epothilone B displays cytotoxic antitumor activity at low nanomolar concentrations and also enhances the radiation response in the tumor cells tested; this may be induced by a reduced DNA repair capacity triggered by epothilone B. It was also demonstrated that epothilone B in fact targets microtubules in a more effective manner than paclitaxel. (orig.)

  18. Prediction of clinical toxicity in locally advanced head and neck cancer patients by radio-induced apoptosis in peripheral blood lymphocytes (PBLs)

    International Nuclear Information System (INIS)

    Bordón, Elisa; Henríquez-Hernández, Luis Alberto; Lara, Pedro C; Ruíz, Ana; Pinar, Beatriz; Rodríguez-Gallego, Carlos; Lloret, Marta

    2010-01-01

    Head and neck cancer is treated mainly by surgery and radiotherapy. Normal tissue toxicity due to x-ray exposure is a limiting factor for treatment success. Many efforts have been employed to develop predictive tests applied to clinical practice. Determination of lymphocyte radio-sensitivity by radio-induced apoptosis arises as a possible method to predict tissue toxicity due to radiotherapy. The aim of the present study was to analyze radio-induced apoptosis of peripheral blood lymphocytes in head and neck cancer patients and to explore their role in predicting radiation induced toxicity. Seventy nine consecutive patients suffering from head and neck cancer, diagnosed and treated in our institution, were included in the study. Toxicity was evaluated using the Radiation Therapy Oncology Group scale. Peripheral blood lymphocytes were isolated and irradiated at 0, 1, 2 and 8 Gy during 24 hours. Apoptosis was measured by flow cytometry using annexin V/propidium iodide. Lymphocytes were marked with CD45 APC-conjugated monoclonal antibody. Radiation-induced apoptosis increased in order to radiation dose and fitted to a semi logarithmic model defined by two constants: α and β. α, as the origin of the curve in the Y axis determining the percentage of spontaneous cell death, and β, as the slope of the curve determining the percentage of cell death induced at a determined radiation dose, were obtained. β value was statistically associated to normal tissue toxicity in terms of severe xerostomia, as higher levels of apoptosis were observed in patients with low toxicity (p = 0.035; Exp(B) 0.224, I.C.95% (0.060-0.904)). These data agree with our previous results and suggest that it is possible to estimate the radiosensitivity of peripheral blood lymphocytes from patients determining the radiation induced apoptosis with annexin V/propidium iodide staining. β values observed define an individual radiosensitivity profile that could predict late toxicity due to radiotherapy

  19. Three cases of unresectable locally advanced breast cancer treated with local injection of the new radiosensitization (KORTUC)

    International Nuclear Information System (INIS)

    Shimbo, Taijyu; Yosikawa, Nobuhiko; Yoshioka, H.; Tanaka, Y.; Yoshida, Ken; Uesugi, Yasuo; Narumi, Yoshifumi; Inomata, Taisuke

    2013-01-01

    New radiosensitization therapy named Kochi Oxydol-Radiation Therapy for Unresectabe carcinomas (KORTUC) using a new agent containing 0.5% hydrogen peroxide and 0.83% sodium hyaluronate is the world first treatment developed in Japan. The agent was injected into tumor two times per week under ultrasonographic guidance. Unresectable locally advanced breast cancer is radiation resistance. The local control is difficult in a conventional radiation therapy. In 3 cases, KORTUC was enforced safety, and remarkable effects was admitted. (author)

  20. Radiosensitivity and effect of hypoxia in HPV positive head and neck cancer cells

    International Nuclear Information System (INIS)

    Sørensen, Brita Singers; Busk, Morten; Olthof, Nadine; Speel, Ernst-Jan; Horsman, Michael R.; Alsner, Jan; Overgaard, Jens

    2013-01-01

    Background and purpose: HPV associated Head and Neck Squamous Cell Carcinoma (HNSCC) represents a distinct subgroup of HNSCC characterized by a favorable prognosis and a distinct molecular biology. Previous data from the randomized DAHANCA 5 trial indicated that HPV positive tumors did not benefit from hypoxic modifications by Nimorazole during radiotherapy, whereas a significant benefit was observed in the HPV negative tumors. However, more studies have demonstrated equal frequencies of hypoxic tumors among HPV-positive and HPV-negative tumors. The aim of the present study was to determine radiosensitivity, the impact of hypoxia and the effect of Nimorazole in HPV positive and HPV negative cell lines. Materials and method: The used cell lines were: UDSCC2, UMSCC47 and UPCISCC90 (HPV positive) and FaDu DD , UTSCC33 and UTSCC5 (HPV negative). Cells were cultured under normoxic or hypoxic conditions, and gene expression levels of previously established hypoxia induced genes were assessed by qPCR. Cells were irradiated with various doses under normoxia, hypoxia or hypoxia +1 mM Nimorazole, and the clonogenic survival was determined. Results: The HPV positive and HPV negative cell lines exhibited similar patterns of upregulation of hypoxia induced genes in response to hypoxia. The HPV positive cell lines were up to 2.4 times more radiation sensitive than HPV negative cell lines. However, all HPV positive cells displayed the same response to hypoxia in radiosensitivity, with an OER in the range 2.3–2.9, and a sensitizer effect of Nimorazole of 1.13–1.29, similar to HPV negative cells. Conclusions: Although HPV positive cells had a markedly higher radiosensitivity compared to HPV negative cells, they displayed the same relative radioresistance under hypoxia and the same relative sensitizer effect of Nimorazole. The clinical observation that HPV positive patients do not seem to benefit from Nimorazole treatment is not due to inherent differences in hypoxia sensitivity

  1. Novel Hsp90 inhibitor NVP-AUY922 radiosensitizes prostate cancer cells.

    Science.gov (United States)

    Gandhi, Nishant; Wild, Aaron T; Chettiar, Sivarajan T; Aziz, Khaled; Kato, Yoshinori; Gajula, Rajendra P; Williams, Russell D; Cades, Jessica A; Annadanam, Anvesh; Song, Danny; Zhang, Yonggang; Hales, Russell K; Herman, Joseph M; Armour, Elwood; DeWeese, Theodore L; Schaeffer, Edward M; Tran, Phuoc T

    2013-04-01

    Outcomes for poor-risk localized prostate cancers treated with radiation are still insufficient. Targeting the "non-oncogene" addiction or stress response machinery is an appealing strategy for cancer therapeutics. Heat-shock-protein-90 (Hsp90), an integral member of this machinery, is a molecular chaperone required for energy-driven stabilization and selective degradation of misfolded "client" proteins, that is commonly overexpressed in tumor cells. Hsp90 client proteins include critical components of pathways implicated in prostate cancer cell survival and radioresistance, such as androgen receptor signaling and the PI3K-Akt-mTOR pathway. We examined the effects of a novel non-geldanamycin Hsp90 inhibitor, AUY922, combined with radiation (RT) on two prostate cancer cell lines, Myc-CaP and PC3, using in vitro assays for clonogenic survival, apoptosis, cell cycle distribution, γ-H2AX foci kinetics and client protein expression in pathways important for prostate cancer survival and radioresistance. We then evaluated tumor growth delay and effects of the combined treatment (RT-AUY922) on the PI3K-Akt-mTOR and AR pathways in a hind-flank tumor graft model. We observed that AUY922 caused supra-additive radiosensitization in both cell lines at low nanomolar doses with enhancement ratios between 1.4-1.7 (p < 0.01). RT-AUY922 increased apoptotic cell death compared with either therapy alone, induced G 2-M arrest and produced marked changes in client protein expression. These results were confirmed in vivo, where RT-AUY922 combination therapy produced supra-additive tumor growth delay compared with either therapy by itself in Myc-CaP and PC3 tumor grafts (both p < 0.0001). Our data suggest that combined RT-AUY922 therapy exhibits promising activity against prostate cancer cells, which should be investigated in clinical studies.

  2. No Effect of the Transforming Growth Factor {beta}1 Promoter Polymorphism C-509T on TGFB1 Gene Expression, Protein Secretion, or Cellular Radiosensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Reuther, Sebastian; Metzke, Elisabeth [Laboratory of Radiobiology and Experimental Radiooncology, University Hospital Hamburg-Eppendorf, Hamburg (Germany); Bonin, Michael [Department of Medical Genetics, University of Tuebingen (Germany); Petersen, Cordula [Clinic of Radiotherapy and Radiooncology, University Hospital Hamburg-Eppendorf, Hamburg (Germany); Dikomey, Ekkehard, E-mail: dikomey@uke.de [Laboratory of Radiobiology and Experimental Radiooncology, University Hospital Hamburg-Eppendorf, Hamburg (Germany); Raabe, Annette [Laboratory of Radiobiology and Experimental Radiooncology, University Hospital Hamburg-Eppendorf, Hamburg (Germany)

    2013-02-01

    Purpose: To study whether the promoter polymorphism (C-509T) affects transforming growth factor {beta}1 gene (TGFB1) expression, protein secretion, and/or cellular radiosensitivity for both human lymphocytes and fibroblasts. Methods and Materials: Experiments were performed with lymphocytes taken either from 124 breast cancer patients or 59 pairs of normal monozygotic twins. We used 15 normal human primary fibroblast strains as controls. The C-509T genotype was determined by polymerase chain reaction-restriction fragment length polymorphism or TaqMan single nucleotide polymorphism (SNP) genotyping assay. The cellular radiosensitivity of lymphocytes was measured by G0/1 assay and that of fibroblasts by colony assay. The amount of extracellular TGFB1 protein was determined by enzyme-linked immunosorbent assay, and TGFB1 expression was assessed via microarray analysis or reverse transcription-polymerase chain reaction. Results: The C-509T genotype was found not to be associated with cellular radiosensitivity, neither for lymphocytes (breast cancer patients, P=.811; healthy donors, P=.181) nor for fibroblasts (P=.589). Both TGFB1 expression and TGFB1 protein secretion showed considerable variation, which, however, did not depend on the C-509T genotype (protein secretion: P=.879; gene expression: lymphocytes, P=.134, fibroblasts, P=.605). There was also no general correlation between TGFB1 expression and cellular radiosensitivity (lymphocytes, P=.632; fibroblasts, P=.573). Conclusion: Our data indicate that any association between the SNP C-509T of TGFB1 and risk of normal tissue toxicity cannot be ascribed to a functional consequence of this SNP, either on the level of gene expression, protein secretion, or cellular radiosensitivity.

  3. DNA-Dependent Protein Kinase As Molecular Target for Radiosensitization of Neuroblastoma Cells.

    Directory of Open Access Journals (Sweden)

    M Emmy M Dolman

    Full Text Available Tumor cells might resist therapy with ionizing radiation (IR by non-homologous end-joining (NHEJ of IR-induced double-strand breaks. One of the key players in NHEJ is DNA-dependent protein kinase (DNA-PK. The catalytic subunit of DNA-PK, i.e. DNA-PKcs, can be inhibited with the small-molecule inhibitor NU7026. In the current study, the in vitro potential of NU7026 to radiosensitize neuroblastoma cells was investigated. DNA-PKcs is encoded by the PRKDC (protein kinase, DNA-activated, catalytic polypeptide gene. We showed that PRKDC levels were enhanced in neuroblastoma patients and correlated with a more advanced tumor stage and poor prognosis, making DNA-PKcs an interesting target for radiosensitization of neuroblastoma tumors. Optimal dose finding for combination treatment with NU7026 and IR was performed using NGP cells. One hour pre-treatment with 10 μM NU7026 synergistically sensitized NGP cells to 0.63 Gy IR. Radiosensitizing effects of NU7026 increased in time, with maximum effects observed from 96 h after IR-exposure on. Combined treatment of NGP cells with 10 μM NU7026 and 0.63 Gy IR resulted in apoptosis, while no apoptotic response was observed for either of the therapies alone. Inhibition of IR-induced DNA-PK activation by NU7026 confirmed the capability of NGP cells to, at least partially, resist IR by NHEJ. NU7026 also synergistically radiosensitized other neuroblastoma cell lines, while no synergistic effect was observed for low DNA-PKcs-expressing non-cancerous fibroblasts. Results obtained for NU7026 were confirmed by PRKDC knockdown in NGP cells. Taken together, the current study shows that DNA-PKcs is a promising target for neuroblastoma radiosensitization.

  4. E3 Ligase cIAP2 Mediates Downregulation of MRE11 and Radiosensitization in Response to HDAC Inhibition in Bladder Cancer.

    Science.gov (United States)

    Nicholson, Judith; Jevons, Sarah J; Groselj, Blaz; Ellermann, Sophie; Konietzny, Rebecca; Kerr, Martin; Kessler, Benedikt M; Kiltie, Anne E

    2017-06-01

    The MRE11/RAD50/NBS1 (MRN) complex mediates DNA repair pathways, including double-strand breaks induced by radiotherapy. Meiotic recombination 11 homolog (MRE11) is downregulated by histone deacetylase inhibition (HDACi), resulting in reduced levels of DNA repair in bladder cancer cells and radiosensitization. In this study, we show that the mechanism of this downregulation is posttranslational and identify a C-terminally truncated MRE11, which is formed after HDAC inhibition as full-length MRE11 is downregulated. Truncated MRE11 was stabilized by proteasome inhibition, exhibited a decreased half-life after treatment with panobinostat, and therefore represents a newly identified intermediate induced and degraded in response to HDAC inhibition. The E3 ligase cellular inhibitor of apoptosis protein 2 (cIAP2) was upregulated in response to HDAC inhibition and was validated as a new MRE11 binding partner whose upregulation had similar effects to HDAC inhibition. cIAP2 overexpression resulted in downregulation and altered ubiquitination patterns of MRE11 and mediated radiosensitization in response to HDAC inhibition. These results highlight cIAP2 as a player in the DNA damage response as a posttranscriptional regulator of MRE11 and identify cIAP2 as a potential target for biomarker discovery or chemoradiation strategies in bladder cancer. Cancer Res; 77(11); 3027-39. ©2017 AACR . ©2017 American Association for Cancer Research.

  5. Ellagic acid radiosensitizes tumor cells by evoking apoptotic pathway

    International Nuclear Information System (INIS)

    Ahire, Vidhula R.; Mishra, K.P.

    2016-01-01

    Cancer causes millions of deaths each year globally. In most patients, the cause of treatment failure is found associated with the resistance to chemotherapy and radiotherapy. The development of tumor cell resistance evokes multiple intracellular molecular pathways. In addition, the limitation in treatment outcome arises due to unintended cytotoxic effects of the synthetic anticancer drugs to normal cells and tissues. Considerable focus of research is, therefore, devoted to examine plant-based herbal compounds which may prove potential anticancer drug for developing effective cancer therapy. Research results from our laboratory have shown that ellagic acid (EA), a natural flavonoid displays enhanced tumor toxicity in combination with gamma radiation to many types of cancers in vitro as well as in vivo. Studies on the underlying mechanisms of toxicity suggest that EA employs the cellular signaling pathways in producing the observed effects. This paper gives an account of molecular mechanisms of EA-induced apoptosis process in tumor cytotoxicity. It is suggested that EA acts as a novel radiosensitizer for tumors and a radioprotector for normal cells which may offer a novel protocol for cancer treatment. (author)

  6. ATM-induced radiosensitization in vitro and in vivo

    International Nuclear Information System (INIS)

    Choi, E. K.; Ahn, S. D.; Rhee, Y. H.; Chung, H. S.; Ha, S. W; Song, C. W.; Griffin, R. J.; Park, H. J.

    2003-01-01

    It has been known that ATM plays a central role in response of cells to ionizing radiation by enhancing DNA repair. We have investigated the feasibility of increasing radiosensitivity of tumor cells with the use of ATM inhibitors such as caffeine, pentoxifylline and wortmannin. Human colorectal cancer RKO.C cells and RKO-ATM cells (RKO cells overexpressing ATM) were used in the present study. The clonogenic cell survival in vitro indicated that RKO-ATM cells were markedly radioresistant than RKO.C cells. Treatment with 3 mM of caffeine significantly increased the radiosensitivity of cells, particulary the RKO-ATM cells, so that the radiosensitivity of RKO.C cells and RKO-ATM cells were almost similar. The radiation induced G2/M arrest in RKO-ATM cells was noticeably longer than that in RKO.C cells and caffeine treatment significantly reduced the length of the radiation induced G2/M arrest in both RKO.C and RKO-ATM cells. Pentoxifylline and wortmannin were also less effective than caffeine to radiosensitize RKO.C or RKO-ATM cells. However, wortmannin was more effective than caffeine against human lung adenocarcinoma A549 cells indicating the efficacy of ATM inhibitor to increase radiosensitivity is cell line dependent. For in vivo study, RKO.C cells were injected s.c. into the hind-leg of BALB/c-nuslc nude mice, and allowed to grow to 130mm3 tumor. The mice were i.p. injected with caffeine solution or saline and the tumors irradiated with 10 Gy of X-rays. The radiation induced growth delay was markedly increased by 1-2 mg/g of caffeine. It was concluded that caffeine increases radiosensitivity of tumor cells by inhibiting ATM kinase function, thereby inhibiting DNA repair, that occurs during the G2/M arrest after radiation

  7. Feasibility study of Anti-MUC1 aptamer use as vector target director of 1,10 phenantrolin for radiosensitization of breast cancer cells

    International Nuclear Information System (INIS)

    Alves, Laís Nascimento

    2017-01-01

    With the rising incidence of cancer and this disease as global public health dilemma, there is an alarming need of studying new cancer therapies. To achieve the development of efficient agents is essential to understand the fundamental mechanisms of carcinogenesis and tumor progression. Overexpression of proteins in malignant tissues, in contrast to expression of the proteins found in normal tissues of the same organ, is crucially important and of great interest for the characterization of potential tumor biomarkers. Following this premise, MUC1 glycoprotein was selected as a therapeutic target in a breast cancer model. In order to determine the viability of the aptA aptamer as radiosensitizers carrier, the toxic compound 1,10 phenanthroline, complexed with Fe(II) was intercalated in the aptamers. The dissociation constant was found at a value of Kd = 30 μM. The selective binding and internalization of the compound was demonstrated. Based on these data, the aptA can be used as carrying vector of molecules such as 1,10-phenanthroline. As a next stage, the evaluation of its in vitro potential as radiosensitizers with the use of ionizing radiation will be done. (author)

  8. Hematoporphyrin derivatives potentiate the radiosensitizing effects of 2-deoxy-D-glucose in cancer cells

    International Nuclear Information System (INIS)

    Dwarakanath, B.S.; Adhikari, J.S.; Jain, Viney

    1999-01-01

    Purpose: Two deoxy-D-glucose (2-DG), an inhibitor of glucose transport and glycolysis, has been shown to differentially inhibit the repair of radiation damage in cancer cells by reducing the flow of metabolic energy. Since hematoporphyrin derivatives (Hpd) inhibit certain enzymes of the respiratory metabolism, resulting in an increase in the glucose usage and glycolysis, Hpd could possibly enhance the energy-linked radiosensitizing effects of 2-DG in cancer cells. The purpose of the present work was to verify this suggestion. Methods and Materials: Two human tumor cell lines (cerebral glioma, BMG-1 and squamous cell carcinoma, 4197) and a murine tumor cell line (Ehrlich ascites tumor [EAT], F-15) in vitro were investigated. A commercially available preparation of Hpd, Photosan-3 (PS-3) was used in the present studies. Cells incubated with 0-10 μg/ml PS-3 for 0-24 h before irradiation were exposed to 2.5 Gy of Co-60 gamma rays and maintained under liquid holding conditions for 1-4 h to facilitate repair. 2-DG (0-5 mM) added at the time of irradiation was present during the liquid holding. Radiation-induced cytogenetic damage (micronuclei formation) and cell death (macrocolony assay) were analyzed as parameters of radiation response. Effects of these radiosensitizers on glucose usage and glycolysis were also studied by measuring the glucose consumption and lactate production using enzymatic assays. Results: The glucose consumption and lactate production of BMG-1 cells (0.83 and 1.43 pmole/cell/h) were twofold higher than in the 4197 cells (0.38 and 0.63 pmole/cell/h). Presence of PS-3 (10 μg/ml) enhanced the rate of glycolysis (glucose consumption and lactate production) in these cells by 35% to 65%, which was reduced by 20% to 40% in the presence of 5 mM 2-DG. In exponentially growing BMG-1 and EAT cells, presence of 2-DG (5 mM; equimolar with glucose) for 4 hours after irradiation increased the radiation-induced micronuclei formation and cell death by nearly 40

  9. The alkylphospholipid, perifosine, radiosensitizes prostate cancer cells both in vitro and in vivo

    International Nuclear Information System (INIS)

    Gao, Yuanhong; Ittmann, Michael; Thompson, Timothy C; Butler, E Brian; Xu, Bo; Teh, Bin S; Ishiyama, Hiromichi; Sun, Mianen; Brinkman, Kathryn L; Wang, Xiaozhen; Zhu, Julie; Mai, Weiyuan; Huang, Ying; Floryk, Daniel

    2011-01-01

    Perifosine is a membrane-targeted alkylphospholipid developed to inhibit the PI3K/Akt pathway and has been suggested as a favorable candidate for combined use with radiotherapy. In this study, we investigated the effect of the combined treatment of perifosine and radiation (CTPR) on prostate cancer cells in vitro and on prostate cancer xenografts in vivo. Human prostate cancer cell line, CWR22RV1, was treated with perifosine, radiation, or CTPR. Clonogenic survival assays, sulforhodamine B cytotoxity assays and cell density assays were used to assess the effectiveness of each therapy in vitro. Measurements of apoptosis, cell cycle analysis by flow cytometry and Western blots were used to evaluate mechanisms of action in vitro. Tumor growth delay assays were used to evaluate radiation induced tumor responses in vivo. In vitro, CTPR had greater inhibitory effects on prostate cancer cell viability and clonogenic survival than either perifosine or radiation treatment alone. A marked increase in prostate cancer cell apoptosis was noted in CTPR. Phosphorylation of AKT-T308 AKT and S473 were decreased when using perifosine treatment or CTPR. Cleaved caspase 3 was significantly increased in the CTPR group. In vivo, CTPR had greater inhibitory effects on the growth of xenografts when compared with perifosine or radiation treatment alone groups. Perifosine enhances prostate cancer radiosensitivity in vitro and in vivo. These data provide strong support for further development of this combination therapy in clinical studies

  10. Alterations in growth phenotype and radiosensitivity after fractionated irradiation of breast carcinoma cells from a single patient

    International Nuclear Information System (INIS)

    Wazer, D.E.; Joyce, M.; Jung, L.; Band, V.

    1993-01-01

    The purpose was to investigate growth regulation and radiosensitivity in surviving clonogens after fractionated irradiation. Four breast carcinoma cell lines isolated from the primary tumor (21NT, 21PT) and metastases (21MT-1, 21MT-2) of a single patient were exposed to cumulative radiation doses of 30 Gy yielding cell lines designated -IR with respect to their parent. The irradiated lines were then compared to their parent for serum- and growth factor-requirements under defined media conditions, ability to proliferate in soft agar, concentration of TGF-alpha in conditioned medium, and radiosensitivity. The irradiated lines showed no change in proliferative doubling times under serum- and growth factor-supplemented media conditions. A single line, 21MT-1-IR, acquired a limited ability to proliferate in serum- and growth factor-deplete medium with a day 2-4 doubling time of 44.5 hr. Three lines, 21MT-1-IR, 21MT-2-IR, and 21NT-IR, formed colonies in soft agar in contrast to none of the unirradiated parent lines. There were significant 6-8 fold increases in conditioned media TGF-alpha concentrations for 21MT-2-IR and 21NT-IR cells. The 21MT-1-IR and 21NT-IR cells were significantly less radiosensitive than their respective parent lines. This decrease in radiosensitivity appeared to be at least partially mediated by a released factor as the radiosensitivity of 21MT-1 cells was significantly decreased by pre-incubation with conditioned medium from 21MT-1-IR cells. Radiation-induced changes in growth phenotype vary with respect to clonal origin of the cell line and may influence the radiosensitivity of surviving clonogens after fractionated treatment. 18 refs., 4 figs., 3 tabs

  11. Ionizing radiation-induced DNA injury and damage detection in patients with breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Borrego-Soto, Gissela; Ortiz-Lopez, Rocio; Rojas-Martinez, Augusto, E-mail: arojasmtz@gmail.com, E-mail: augusto.rojasm@uanl.mx [Departamento de Bioquímica y Medicina Molecular, Facultad de Medicina, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León (Mexico)

    2015-10-15

    Breast cancer is the most common malignancy in women. Radiotherapy is frequently used in patients with breast cancer, but some patients may be more susceptible to ionizing radiation, and increased exposure to radiation sources may be associated to radiation adverse events. This susceptibility may be related to deficiencies in DNA repair mechanisms that are activated after cell-radiation, which causes DNA damage, particularly DNA double strand breaks. Some of these genetic susceptibilities in DNA-repair mechanisms are implicated in the etiology of hereditary breast/ovarian cancer (pathologic mutations in the BRCA 1 and 2 genes), but other less penetrant variants in genes involved in sporadic breast cancer have been described. These same genetic susceptibilities may be involved in negative radiotherapeutic outcomes. For these reasons, it is necessary to implement methods for detecting patients who are susceptible to radiotherapy-related adverse events. This review discusses mechanisms of DNA damage and repair, genes related to these functions, and the diagnosis methods designed and under research for detection of breast cancer patients with increased radiosensitivity. (author)

  12. Effect of electroporation on radiosensitization with cisplatin in two cell lines with different chemo- and radiosensitivity

    International Nuclear Information System (INIS)

    Kranjc, S.; Cemazar, M.; Grosel, A.; Pipan, Z.; Sersa, G.

    2003-01-01

    Aim. Radiosensitization with cisplatin can be enhanced by electroporation of cells and tumours. The aim of this study was to extend our previous studies on two carcinoma tumour models with different chemo- and radiosensitivity in order to evaluate whether this treatment is effective also on less chemo- and radiosensitive tumour cells. Materials and methods. This in vitro study was performed on carcinoma SCK and EAT-E cells. The cytotoxicity of three-modality treatment consisting of cisplatin, electroporation and irradiation was determined by the clonogenic assay. Results. The radiosensitizing effect of cisplatin on the two cell lines was greatly enhanced by electroporation. By this combined treatment, less chemo and radiosensitive EAT-E cells were rendered as sensitive as more chemo and radiosensitive SCK cells. Conclusion. The enhancement of cisplatin-induced radiosensitization of cells by electroporation could be beneficially used in the treatment of intrinsically less chemo- and radiosensitive tumours. (author)

  13. A Meta Analysis of Radiosensitivity on Non-small Cell Lung Cancer 
by Metronidazole Amino Acidum Natrium

    Directory of Open Access Journals (Sweden)

    Weiwei REN

    2012-06-01

    Full Text Available Background and objective The efficacy and safety of radiosensitivity on non-small cell lung cancer (NSCLC using metronidazole amino acidum natrium (CMNa are yet to be proven. This study evaluates the efficacy and safety of radiosensitivity on NSCLC by CMNa to provide references for further clinical practice and research. Methods Relevant randomized controlled trials (RCTs were obtained from the Cochrane library, Pubmed, EMbase, CBM, CNKI, VIP, and Wan Fang databases. Dates were searched through other means. RCTs of radiosensitivity on NSCLC by CMNa were included. The data included in the study were evaluated and analyzed using the Cochrane Collaboration's RevMan 5.1 software. Results A total of 21 RCTs were included. The results of the meta-analyses showed that the total effective rate of the test group that received CMNa plus radiotherapy was higher than that of the control group that received radiotherapy alone (OR=3.29, 95%CI: 2.47-4.39, P<0.000,01 or radiotherapy plus placebo (OR=3.65, 95%CI: 2.25-5.92, P<0.000,01, respectively. No significant differences were found in the quality of life between one and two-year survival rates (P>0.05. No significant differences were found among radiation pneumonitis, radiation esophagitis, hematological toxicity, and cardiotoxicity (P>0.05. Conclusion CMNa plus radiotherapy elicit beneficial effects in the treatment of NSCLC and produce fewer adverse effects. Therefore, this technique can be recommended and applied in clinics.

  14. The combination of olaparib and camptothecin for effective radiosensitization

    Directory of Open Access Journals (Sweden)

    Miura Katsutoshi

    2012-04-01

    Full Text Available Abstract Background Poly (ADP-ribose polymerase-1 (PARP-1 is a key enzyme involved in the repair of radiation-induced single-strand DNA breaks. PARP inhibitors such as olaparib (KU-0059436, AZD-2281 enhance tumor sensitivity to radiation and to topoisomerase I inhibitors like camptothecin (CPT. Olaparib is an orally bioavailable inhibitor of PARP-1 and PARP-2 that has been tested in multiple clinical trials. The purpose of this study was to investigate the characteristics of the sensitizing effect of olaparib for radiation and CPT in order to support clinical application of this agent. Methods DLD-1 cells (a human colorectal cancer cell line and H1299 cells (a non-small cell lung cancer cell line with differences of p53 gene status were used. The survival of these cells was determined by clonogenic assay after treatment with drugs and X-ray irradiation. The γH2AX focus formation assay was performed to examine the influence of olaparib on induction and repair of double-stranded DNA breaks after exposure to radiation or CPT. Results A radiosensitizing effect of olaparib was seen even at 0.01 μM. Its radiosensitizing effect after exposure for 2 h was similar to that after 24 h. H1299 cells with depletion or mutation of p53 were more radioresistant than H1299 cells with wild-type p53. However, similar enhancement of radiosensitization by olaparib was observed with all of the tested cell lines regardless of the p53 status. Olaparib also sensitized cells to CPT. This sensitizing effect was seen at low concentrations of olaparib such as 0.01 μM, and its sensitizing effect was the same at both 0.01 μM and 1 μM. The combination of olaparib and CPT had a stronger radiosensitizing effect. The results of the γH2AX focus assay corresponded with the clonogenic assay findings. Conclusion Olaparib enhanced sensitivity to radiation and CPT at low concentrations and after relatively short exposure times such as 2 h. The radiosensitizing effect of olaprib

  15. Inhibition of UBE2D3 expression attenuates radiosensitivity of MCF-7 human breast cancer cells by increasing hTERT expression and activity.

    Directory of Open Access Journals (Sweden)

    Wenbo Wang

    Full Text Available The known functions of telomerase in tumor cells include replenishing telomeric DNA and maintaining cell immortality. We have previously shown the existence of a negative correlation between human telomerase reverse transcriptase (hTERT and radiosensitivity in tumor cells. Here we set out to elucidate the molecular mechanisms underlying regulation by telomerase of radiosensitivity in MCF-7 cells. Toward this aim, yeast two-hybrid (Y2H screening of a human laryngeal squamous cell carcinoma radioresistant (Hep2R cDNA library was first performed to search for potential hTERT interacting proteins. We identified ubiquitin-conjugating enzyme E2D3 (UBE2D3 as a principle hTERT-interacting protein and validated this association biochemically. ShRNA-mediated inhibition of UBE2D3 expression attenuated MCF-7 radiosensitivity, and induced the accumulation of hTERT and cyclin D1 in these cells. Moreover, down-regulation of UBE2D3 increased hTERT activity and cell proliferation, accelerating G1 to S phase transition in MCF-7 cells. Collectively these findings suggest that UBE2D3 participates in the process of hTERT-mediated radiosensitivity in human breast cancer MCF-7 cells by regulating hTERT and cyclin D1.

  16. Study on relationship between apoptosis-related genes and radiosensitivity of esophageal squamous cell carcinoma

    International Nuclear Information System (INIS)

    Li Huixiang; Wang Yaohe; Shi Yonggang; Gao Dongling; Zhang Yunhan

    2000-01-01

    Objective: To observing the relationship between apoptosis-related genes bcl-2,c-myc, p53 and the radiosensitivity of esophageal squamous cell carcinoma. Methods: The expression levels of bcl-2, c-myc and p53 genes in 57 biopsy samples from patients of esophageal squamous cell carcinoma were detected with the LSAB immunohistochemistry method. All the patients were treated with radiotherapy. The radiotherapeutic effect in these patients was observed and the relation between gene expression and radiosensitivity was analyzed. Results: Compared with the bcl-2-negative group, the radiosensitivity of bcl-2-positive one was lower(P<0.01). The radiosensitivity of p53-positive group was slightly lower than that of the p53-negative one (P<0.05). The c-myc protein expression was not related to radiosensitivity. Conclusion: Detection and comprehensive analysis of bcl-2, c-myc and p53 protein expressions are useful in forecasting the radiotherapeutic effect on squamous cell carcinoma of esophagus

  17. Comparison of radiosensitivities of human autologous normal and neoplastic thyroid epithelial cells

    International Nuclear Information System (INIS)

    Miller, R.C.; Kopecky, K.J.; Hiraoka, T.; Ezaki, H.; Clifton, K.H.

    1986-01-01

    Studies were conducted to examine differences between the radiosensitivities of normal and neoplastic epithelial cells of the human thyroid. Freshly excised thyroid tissues from the tumours of eight patients with papillary carcinoma (PC) and five with follicular adenoma (FA) were cultured in vitro separately from normal thyroid tissue obtained from the surgical margins of the same patients. Plating efficiency of unirradiated control tissue was lower, on average for tumour tissue compared with normal tissue. Radiosensitivity, measured by the 37% inactivation dose D 0 , was greater for carcinoma tissue than for normal tissue in seven out of eight PC cases. Adenomatous tissue was less radiosensitive than normal tissue in four out of five FA cases. This is the first report comparing the radiosensitivity of autologous normal and abnormal epithelial tissue from the human thyroid. (author)

  18. Heat shock protein 90 chaperone complex inhibitor enhanced radiosensitivity through modification of response to hormone and degradation of androgen receptor in hormone sensitive prostate cancer cell line

    International Nuclear Information System (INIS)

    Mitsuhashi, N.; Harashima, K.; Akimoto, T.

    2003-01-01

    It is easily speculated that androgen or androgen deprivation affects proliferative activity or radiosensitivity, but there has been enough information how androgen or androgen deprivation influences the response to radiation. In this setting, the effect of dihydrotestosterone (DHT) on cellular growth and radiosensitivity was examined in hormone-responsive human prostate cancer cell line (LnCap). The binding of androgen receptor (AR) with heat shock protein 90 (Hsp90) plays an important role in stability of the function of receptor. It was, therefore, examined how Hsp90 chaperone complex inhibitor modified the effect of DHT on radiosensitivity in addition to the effect of DHT, especially focusing on AR and its downstream signal transduction pathways. Hydroxy-flutamide (OH-flutamide) was also used to confirm the effect of activation of AR on radiosensitivity because AR of LnCap has a point mutation, leading to activation of AR caused by the binding of OH-flutamide. Radicicol was used as a Hsp90 chaperone complex inhibitor, and incubated with cells at a concentration of 500 nM. Radicicol was incubated with cells for 9 h, and cells were irradiated 1 h after the start of incubation. DHT and OH-flutamide were incubated with cells until staining. DHT or OH-flutamide resulted in stimulation of cellular growth in contrast to inhibition of cellular growth caused by higher concentrations, so that we adopted 1 nM as a concentration of DHT and 1μM as a concentration of OH-flutamide. DHT or OH-flutamide in combination with radiation resulted in slight decrease in radiosensitivity compared with radiation alone. Radicicol at a concentration of 500 nM in combination with DHT or OH-flutamide abolished decrease in radiosensitivity caused by DHT or OH-flutamide. In terms of the expression of AR, radicicol in combination with radiation and/or DHT, OH-flutamide induced degradation of AR. In consistent with degradation of AR, the expression of prostate specific antigen (PSA) decreased

  19. Radiosensitizers and protectors

    International Nuclear Information System (INIS)

    Nori, D.; Kim, J.H.; Hilaris, B.; Chu, F.C.

    1987-01-01

    Over the past decades, various physical, biological, and clinical strategies have been investigated to improve the therapeutic effectiveness of radiation. One of these efforts has been to develop chemical radiosensitizers and protectors. In the broadest sense, a radiation sensitizer is any agent that enhances the cytolethal effects of radiation. Drugs that selectively protect tissues from radiation injury are under active study. This chapter briefly reviews the present status of chemical radiosensitizers and protectors. The discussion of sensitizers will be limited to the oxic cell and hypoxic cell radiosensitizers and their clinical applications

  20. Characterization of tumorigenicity and radio-sensitivity markers by an ex vivo approach. In vivo identification of p53 dependent radio-sensitivity markers

    International Nuclear Information System (INIS)

    Alvarez, S.

    2003-12-01

    After a detailed discussion of the relationship between cancer and genetic instability, of the structure, activation mechanisms, activity and biological functions of the p53 protein, a presentation of p53 mutants, and a recall of the effects of ionizing radiations, the author reports a biology research during which he investigated a cell model established from rat embryo lungs treated with Benzo[a]pyrene and made of tumoral lines muted by the p53 gene. He tried to identify markers which could report differences of tumorigenicity and radio-sensitivity observed in these different lines. He also tried to characterize radio-sensitivity molecular markers dependent on the p53 gene in a context of normal cells

  1. Effect of Quercetin on radio-sensitivity of HeLa cells

    International Nuclear Information System (INIS)

    Wu Xiaofen; Hong Chengjiao; Guo Wenxiu; Pan Yanling; Zhang Baoguo

    2011-01-01

    In order to investigate the mechanism of Quercetin on radio-sensitivity of human Uterine Cervix Cancer HeLa cells, HeLa cells were cultured in different concentrations of Quercetin and different doses of irradiation. The clonogenic assay was used to observe the cell survival rate. The repair of DNA double-strand breaks and effect of Quercetin combination of radiation on the cell cycle were detected by flow cytometry. The results show that the radio-sensitivity of Quercetin on HeLa cells was obvious and the unrepaired DSBs after irradiation increased, but did not decrease G2/M cell cycle arrest. From this it can be inferred that the effect on HeLa cell radio-sensitivity may be related to the inhibition of the repair of DNA double-strand breaks induced by Quercetin, but it dose not reveal a significant relation with the cell cycle and G2/M arrest. (authors)

  2. Liposome based radiosensitizer cancer therapy

    DEFF Research Database (Denmark)

    Pourhassan, Houman

    Liposome-encapsulated chemotherapeutics have been used in the treatment of a variety of cancers and are feasible for use as mono-therapeutics as well as for combination therapy in conjunction with other modalities. Despite widespread use of liposomal drugs in cancer patient care, insufficient drug...... biomolecules. By modulating the liposomal membrane, liposomes can become sensitive towards enzymatically-driven destabilization and/or functionalization, thereby allowing control of the release of encapsulated therapeutics within the diseased tissue upon intrinsic stimulation from tumor-associated enzymes...... in tumor-bearing mice.The safety and efficacy of sPLA2-sensitive liposomal L-OHP was assessed in sPLA2-deficient FaDu hypopharyngeal squamous cell carcinoma and sPLA2-expressing Colo205 colorectal adenocarcinoma. Also, the feasibility of multimodal cancer therapy employing L-OHP encapsulated in MMP...

  3. Evaluation of the single radiosensitivity in patients subjected to medical exposure that show severe skin reactions

    International Nuclear Information System (INIS)

    Di Giorgio, M.; Vallerga, M.B.; Portas, M.; Perez, M.R.

    2006-01-01

    The Burnt Hospital of the Buenos Aires City Government (HQGCBA) it is a hospital of reference of the Net of Medical Responses in Radiological Emergencies of the Argentine Republic. In the mark of an agreement among the HQGCBA and the Authority Regulatory Nuclear (ARN), it is in execution a study protocol for the one boarding diagnoses and therapeutic of radioinduced cutaneous leisure. They exist individual variations that can condition the response to the ionizing radiations (IR), so much in accidental exposures as having programmed (radiotherapy, radiology interventionist). In this context, the individual radiosensitivity is evaluated in the patients signed up in this protocol that presented sharp or late cutaneous reactions, with grades of severity 3-4 (approaches EORTC/RTOG). The capacity of repair of the DNA was evaluated in outlying blood lymphocytes irradiated in vitro (2 Gy, gamma of Co-60) by means of the micronucleus techniques and comet essay in alkaline conditions. In this work two cases in those that is applied this study protocol, the therapeutic answer and its correlate with the discoveries of the radiosensitivity tests is presented. Case 1: patient of feminine sex, subjected to external radiotherapy by a breast infiltrating ductal carcinoma; developed sharp cutaneous radiotoxicity grade 3 (confluent humid epithelitis) that motivate the interruption of the treatment. Case 2: patient of masculine sex, subjected to a coronary angioplasty (interventionist radiology); developed late cutaneous radiotoxicity grade 4 (ulceration in dorsal region). Both patients were treated with topical trolamine associated to systemic administration of pentoxiphiline and antioxidants. The therapeutic answer is evaluated by means of clinical pursuit, photographic serial register and complementary exams (thermography and ultrasonography of high frequency). In the case 1 the answer was very favorable, with precocious local improvement and complete remission of symptoms and

  4. Modern concepts for basic radiobiological factors characterizing tumor tissue radiosensitivity

    International Nuclear Information System (INIS)

    Gocheva, L.; Sergieva, K.

    2002-01-01

    Traditionally radiotherapy is prescribed at doses consistent with the expected therapeutic response and tolerance of tumor and normal tissues without consideration to individual differences in radiosensitivity. However, the basic radiobiological knowledge and clinical experience along this line point to significant variations in the observed therapeutic results. It has been established that cells and tissues under experimental and clinical conditions manifest a wide spectrum of individual radiosensitivity. The aim of this survey is to outline the current concepts for the basic radiobiological factors influencing tumor radiosensitivity. A thorough discussion is done of the essence, mechanisms of action, methods of determination and measurement, and effect on the prognosis in patients with malignant diseases of a number of radiobiological factors, such as: tumor-cell proliferation, apoptosis, tumor hypoxia and neovascularization. Although the knowledge of the mechanisms of radiosensitivity is constantly expanding, its clinical implementation is still rather limited. The true role of radiosensitivity in predicting the therapeutic response should be more accurately defined. (authors)

  5. Taxane-mediated radiosensitization derives from chromosomal missegregation on tripolar mitotic spindles orchestrated by AURKA and TPX2.

    Science.gov (United States)

    Orth, M; Unger, K; Schoetz, U; Belka, C; Lauber, K

    2018-01-04

    Taxane-based radiochemotherapy is a central treatment option for various cancer entities in locally advanced stages. The therapeutic synergism of this combined modality approach due to taxane-mediated radiosensitization of cancer cells is well-known. However, the underlying molecular mechanisms remain largely elusive, and mechanism-derived predictive markers of taxane-based radiochemotherapy are currently not available. Here, we show that clinically relevant doses of Paclitaxel, the prototype taxane, stimulate a tripolar mode of mitosis leading to chromosomal missegregation and aneuploidization rather than interfering with cell cycle progression. This distinct mitotic phenotype was interlinked with Paclitaxel-mediated radiosensitization via overexpression of mitotic Aurora kinase A (AURKA) and its cofactor TPX2 whose knockdown rescued the bipolar mode of cell division and largely attenuated the radiosensitizing effects of Paclitaxel. In the cancer genome atlas (TCGA) lung adenocarcinoma cohort, high expression levels of AURKA and TPX2 were associated with specifically improved overall survival upon taxane-based radiochemotherapy, but not in case of non-taxane-based radiochemotherapy, chemo- or radiotherapy only. Thus, our data provide insights into Paclitaxel-mediated radiosensitization on a mechanistic and molecular level and identify AURKA and TPX2 as the first potential mechanism-based, predictive markers of taxane-based radiochemotherapy.

  6. Radiosensitivity in plants

    International Nuclear Information System (INIS)

    Nauman, A.F.

    1979-01-01

    The report presents a compilation of available data on the sensitivity of plants to ionizing radiation, and provides basic information on methods of determining such sensitivities, or of estimating radiosensitivities by calcuation of the nuclear factors upon which they depend. The scope of the data presented here is necessarily limited to the most generally useful radiobiological end points and to the most commonly-used types of radiation. Many of the factors which influence radiosensitivity, particularly nuclear factors, will be discussed. Emphasis will be upon whole-plant studies done at Brookhaven National Laboratory by A.H. Sparrow and his associates, since these studies are the source of most of the available radiosensitivity data and of all the sensitivity predictions listed here. Data presented here include summaries of experimentally-determined radiosensitivities at various end points for both herbaceous and woody higher plants, and for a few species of ferns and lower plants. The algae and fungi have not been considered here due to space limitations

  7. Radiosensitivity in plants

    Energy Technology Data Exchange (ETDEWEB)

    Nauman, A F

    1979-01-01

    The report presents a compilation of available data on the sensitivity of plants to ionizing radiation, and provides basic information on methods of determining such sensitivities, or of estimating radiosensitivities by calcuation of the nuclear factors upon which they depend. The scope of the data presented here is necessarily limited to the most generally useful radiobiological end points and to the most commonly-used types of radiation. Many of the factors which influence radiosensitivity, particularly nuclear factors, will be discussed. Emphasis will be upon whole-plant studies done at Brookhaven National Laboratory by A.H. Sparrow and his associates, since these studies are the source of most of the available radiosensitivity data and of all the sensitivity predictions listed here. Data presented here include summaries of experimentally-determined radiosensitivities at various end points for both herbaceous and woody higher plants, and for a few species of ferns and lower plants. The algae and fungi have not been considered here due to space limitations.

  8. Analysis of enzyme targeting intraoperative radiosensitization therapy (KORTUC-IORT) for abdominal malignant tumors

    International Nuclear Information System (INIS)

    Nishioka, Akihito; Kariya, Shinji; Kataoka, Y.; Miyatake, Kana; Tadokoro, Michiko; Hamada, Norihiko; Kubota, Kei; Ogawa, Yasuhiro

    2013-01-01

    We developed a new radiosensitizer injection containing hydrogen peroxide and sodium hyaluronate just followed by intraoperative radiotherapy (IORT) for locally advanced pancreatic cancer, named KORTUC-IORT (Kochi Oxydol-Radiation Therapy for Unresectable Carcinomas+IORT). Fourteen patients were treated with KORTUC-IORT, external beam radiotherapy, and systemic chemotherapy. All treatments related with KORTUC-IORT were well tolerated, with few adverse effects. The 1- and 2-year survival rates were 75% and 25%, respectively. The median survival period is 15 months. The present formulation can be delivered safely and effectively under the conditions used. (author)

  9. Radiosensitization by the histone deacetylase inhibitor vorinostat under hypoxia and with capecitabine in experimental colorectal carcinoma

    International Nuclear Information System (INIS)

    Saelen, Marie Grøn; Ree, Anne Hansen; Kristian, Alexandr; Fleten, Karianne Giller; Furre, Torbjørn; Hektoen, Helga Helseth; Flatmark, Kjersti

    2012-01-01

    The histone deacetylase inhibitor vorinostat is a candidate radiosensitizer in locally advanced rectal cancer (LARC). Radiosensitivity is critically influenced by hypoxia; hence, it is important to evaluate the efficacy of potential radiosensitizers under variable tissue oxygenation. Since fluoropyrimidine-based chemoradiotherapy (CRT) is the only clinically validated regimen in LARC, efficacy in combination with this established regimen should be assessed in preclinical models before a candidate drug enters clinical trials. Radiosensitization by vorinostat under hypoxia was studied in four colorectal carcinoma cell lines and in one colorectal carcinoma xenograft model by analysis of clonogenic survival and tumor growth delay, respectively. Radiosensitizing effects of vorinostat in combination with capecitabine were assessed by evaluation of tumor growth delay in two colorectal carcinoma xenografts models. Under hypoxia, radiosensitization by vorinostat was demonstrated in vitro in terms of decreased clonogenicity and in vivo as inhibition of tumor growth. Adding vorinostat to capecitabine-based CRT increased radiosensitivity of xenografts in terms of inhibited tumor growth. Vorinostat sensitized colorectal carcinoma cells to radiation under hypoxia in vitro and in vivo and improved therapeutic efficacy in combination with capecitabine-based CRT in vivo. The results encourage implementation of vorinostat into CRT in LARC trials

  10. Radiosensitization by the histone deacetylase inhibitor vorinostat under hypoxia and with capecitabine in experimental colorectal carcinoma.

    Science.gov (United States)

    Saelen, Marie Grøn; Ree, Anne Hansen; Kristian, Alexandr; Fleten, Karianne Giller; Furre, Torbjørn; Hektoen, Helga Helseth; Flatmark, Kjersti

    2012-09-27

    The histone deacetylase inhibitor vorinostat is a candidate radiosensitizer in locally advanced rectal cancer (LARC). Radiosensitivity is critically influenced by hypoxia; hence, it is important to evaluate the efficacy of potential radiosensitizers under variable tissue oxygenation. Since fluoropyrimidine-based chemoradiotherapy (CRT) is the only clinically validated regimen in LARC, efficacy in combination with this established regimen should be assessed in preclinical models before a candidate drug enters clinical trials. Radiosensitization by vorinostat under hypoxia was studied in four colorectal carcinoma cell lines and in one colorectal carcinoma xenograft model by analysis of clonogenic survival and tumor growth delay, respectively. Radiosensitizing effects of vorinostat in combination with capecitabine were assessed by evaluation of tumor growth delay in two colorectal carcinoma xenografts models. Under hypoxia, radiosensitization by vorinostat was demonstrated in vitro in terms of decreased clonogenicity and in vivo as inhibition of tumor growth. Adding vorinostat to capecitabine-based CRT increased radiosensitivity of xenografts in terms of inhibited tumor growth. Vorinostat sensitized colorectal carcinoma cells to radiation under hypoxia in vitro and in vivo and improved therapeutic efficacy in combination with capecitabine-based CRT in vivo. The results encourage implementation of vorinostat into CRT in LARC trials.

  11. Radiation therapy of gynecological cancer

    International Nuclear Information System (INIS)

    Nori, D.; Hilaris, B.S.

    1987-01-01

    This book consists of three parts: General Principles; Clinical Applications; and Special Topics. Some of the papers are: Introduction to Basic Radiobiology; Staging and Work-up Procedures for Patients with Gynecological Cancers; Radiation Therapy in the Treatment of Cancer of the Cervix; Role of Interstitial Implantation in Gynecological Cancer; Role of Radiocolloids in Gynecological Cancer; Radiosensitizers and Protectors; and Management of Lymphoma Associated with Pregnancy

  12. Radiosensitization and growth inhibition of cancer cells mediated by an scFv antibody gene against DNA-PKcs in vitro and in vivo

    International Nuclear Information System (INIS)

    Du, Li; Zhou, Ping-Kun; Zhou, Li-Jun; Pan, Xiu-Jie; Wang, Yu-Xiao; Xu, Qin-Zhi; Yang, Zhi-Hua; Wang, Yu; Liu, Xiao-Dan; Zhu, Mao-Xiang

    2010-01-01

    Overexpression of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is commonly occurred in cancers and causes radioresistance and poor prognosis. In present study, the single-chain variable antibody fragments (scFv) targeting DNA-PKcs was developed for the application of radiosensitization in vitro and in vivo. A humanized semisynthetic scFv library and the phage-display antibodies technology were employed to screen DNA-PKcs scFv antibody. DNA-PKcs epitopes were predicted and cloned. A humanized semisynthetic scFv library and the phage-display antibodies technology were employed to screen DNA-PKcs scFv antibody. DNA damage repair was analyzed by comet assay and immunofluorescence detection of γH2AX foci. The radiosensitization in vivo was determined on Balb/c athymic mice transplanted tumours of HeLa cells. Four epitopes of DNA-PKcs have been predicted and expressed as the antigens, and a specific human anti-DNA-PKcs scFv antibody gene, anti-DPK3-scFv, was obtained by screening the phage antibody library using the DNA-PKcs peptide DPK3. The specificity of anti-DPK3-scFv was verified, in vitro. Transfection of HeLa cells with the anti-DPK3-scFv gene resulted in an increased sensitivity to IR, decreased repair capability of DNA double-strand breaks (DSB) detected by comet assay and immunofluorescence detection of γH2AX foci. Moreover, the kinase activity of DNA-PKcs was inhibited by anti-DPK3-scFv, which was displayed by the decreased phosphorylation levels of its target Akt/S473 and the autophosphorylation of DNA-PKcs on S2056 induced by radiation. Measurement of the growth and apoptosis rates showed that anti-DPK3-scFv enhanced the sensitivity of tumours transplanted in Balb/c athymic mice to radiation therapy. The antiproliferation and radiosensitizing effects of anti-DPK3-scFv via targeting DNA-PKcs make it very appealing for the development as a novel biological radiosensitizer for cancer therapeutic potential

  13. Chemosensitivity and radiosensitivity of small cell lung cancer cell lines studied by a newly developed 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) hybrid assay

    International Nuclear Information System (INIS)

    Hida, T.; Ueda, R.; Takahashi, T.; Watanabe, H.; Kato, T.; Suyama, M.; Sugiura, T.; Ariyoshi, Y.

    1989-01-01

    The 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) hybrid assay was developed by technically combining the human tumor clonogenic assay and the MTT assay to make the most of both assays. This assay was able to estimate the in vitro growth of cultured cell lines and of tumor cells in pleural effusion, suggesting the possibility of its use for assessment of chemosensitivity and radiosensitivity of fresh tumor samples. Multiple cell lines [including morphological and/or phenotypical in vitro converters and cisplatin (CDDP)-resistant lines] were established from three patients with small cell lung cancer at different stages of the disease. Chemosensitivity of these cell lines to four commonly used chemotherapeutic drugs was tested by the MTT hybrid assay. SK1 and SK3 lines were established from Patient S. K. before and after chemotherapy and radiotherapy, respectively. SK3/CDDP, a CDDP-resistant line derived from the SK3 line, was 30-fold more resistant to CDDP [50% inhibiting dose (IC50), 21.5 micrograms/ml] than the SK1 line. In Patient M. O., MOA2/CDDP, a CDDP-resistant line derived from MOA2 (an in vitro converter from the MO line), was 41-fold more resistant to CDDP (IC50, 37 micrograms/ml) than the parent MO line. From Patient T. M., TM1 and TM2 lines were established before and after chemotherapy, respectively. The latter showed 6-fold more resistance to CDDP than the former. Chemosensitivity of these lines to three other drugs, 4-hydroperoxycyclophosphamide, Adriamycin, and etoposide, suggested cross-resistance between CDDP and 4-hydroperoxycyclophosphamide. Radiosensitivity study was also carried out with the MTT hybrid assay. The MOA2 line was more resistant [Do, 3.0 Gy; extrapolation number (n), 4.0] than the parental MO line (Do, 1.6 Gy; n, 2.1). There was no clear difference in radiosensitivity between the cell lines established before and after radiation therapy in Patient S. K

  14. Comparison of microwave and magnetic nanoparticle hyperthermia radiosensitization in murine breast tumors

    Science.gov (United States)

    Giustini, Andrew J.; Petryk, Alicia A.; Hoopes, Paul J.

    2011-03-01

    Hyperthermia has been shown to be an effective radiosensitizer. Its utility as a clinical modality has been limited by a minimally selective tumor sensitivity and the inability to be delivered in a tumor-specific manner. Recent in vivo studies (rodent and human) have shown that cancer cell-specific cytotoxicity can be effectively and safely delivered via iron oxide magnetic nanoparticles (mNP) and an appropriately matched noninvasive alternating magnetic field (AMF). To explore the tumor radiosensitization potential of mNP hyperthermia we used a syngeneic mouse breast cancer model, dextran-coated 110 nm hydrodynamic diameter mNP and a 169 kHz / 450 Oe (35.8 kA/m) AMF. Intradermally implanted (flank) tumors (150 +/- 40 mm3) were treated by injection of 0.04 ml mNP (7.5 mg Fe) / cm3 into the tumor and an AMF (35.8 kA/m and 169 kHz) exposure necessary to achieve a CEM (cumulative equivalent minute) thermal dose of 60 (CEM 60). Tumors were treated with mNP hyperthermia (CEM 60), radiation alone (15 Gy, single dose) and in combination. Compared to the radiation and heat alone treatments, the combined treatment resulted in a greater than two-fold increase in tumor regrowth tripling time (tumor treatment efficacy). None of the treatments resulted in significant normal tissue toxicity or morbidity. Studies were also conducted to compare the radiosensitization effect of mNP hyperthermia with that of microwave-induced hyperthermia. The effects of incubation of nanoparticles within tumors (to allow nanoparticles to be endocytosed) before application of AMF and radiation were determined. This preliminary information suggests cancer cell specific hyperthermia (i.e. antibody-directed or anatomically-directed mNP) is capable of providing significantly greater radiosensitization / therapeutic ratio enhancement than other forms of hyperthermia delivery.

  15. Cellular radiosensitivity in human severe-combined-immunodeficiency (SCID) syndromes

    International Nuclear Information System (INIS)

    Sproston, Anthony R.M.; West, Catharine M.L.; Hendry, Jolyon H.

    1997-01-01

    Purpose: The aim of the work was to establish to what extent a variety of human severe-combined-immunodeficiency (SCID) disorders are associated with in vitro cellular hypersensitivity to ionizing radiation. Materials and methods: A study was made of fibroblast strains established from individuals with adenosine deaminase deficiency, T(-)B(-) SCID, Omenn's syndrome and a SCID heterozygote. For comparison, an assessment was also made of the radiosensitivity of a series of fibroblast strains derived from: normal donors, a patient with ataxia-telangiectasia (A-T) and an A-T heterozygote. Radiosensitivity was determined using a clonogenic assay following both high (HDR) and low (LDR) dose-rate irradiation. Results: Following HDR irradiation, the fibroblast strains derived from the different human SCID disorders displayed a wide range of radiosensitivity: the adenosine deaminase deficiency cells were similar in radiosensitivity to normal fibroblasts, T(-)B(-) cells were as hypersensitive to radiation as A-T cells and the Omenn's syndrome cells showed intermediate radiosensitivity. However, whereas all four normal cell strains studied showed significant LDR sparing, none of the SCID fibroblasts did. Conclusions: These data indicate that human SCID is variable in terms of radiosensitivity depending on the particular defect. In addition, the lack of LDR sparing of radiation-induced damage suggests the involvement of some form(s) of DNA repair defect in all the human SCID syndromes

  16. Genetic factors affecting radiosensitivity and cancer predisposition: application of a continuous low dose-rate irradiation colony formation assay to select radiosensitive retinoblastoma family members for correction with a cDNA library

    International Nuclear Information System (INIS)

    Wilson, P.F.; Nagasawa, H.; Bedford, J.S.; Little, J.B.

    2003-01-01

    Full text: The aim of this study is to identify new or undescribed functions of radiosensitivity and genomic instability genes using a continuous low dose-rate colony formation assay. This assay expands on the standard colony formation assay, whereby colony formation ability (retention of proliferative capacity) is measured during continuous low dose-rate irradiation rather than 10-14 days following the completion of such exposures. This approach has previously employed by the Bedford laboratory to identify a Prkdc (DNA-PKcs) mutant of CHO cells, irs-20. In this study we examine the growth response of fibroblasts derived from recently identified radiosensitive retinoblastoma family members, both affected probands and their unaffected parents, and various apparently normal fibroblast lines obtained from the NIGMS Human Genetic Cell Repository (Coriell Medical Institute, Camden, NJ). Colony formation was assayed by plating single cells, exposing them at 37 deg C to continuous Cs-137 gamma irradiation at dose rates of 0.5-8.5 cGy/h, and scoring survivors as colonies with >100 viable cells. The retinoblastoma family members display severely limited growth (survival less than 10E-3) at dose rates greater than 2-2.5 cGy/h, while the apparently normal cell lines do not display such inhibited growth until 6-7 cGy/h. Two of the retinoblastoma family cell lines, MF-6F and MF-15F (both unaffected but radiosensitive parents), were selected as targets of transfection with a viral cDNA library (ViraPort human cDNA library, Stratagene Cloning Systems, La Jolla, CA) and subjected to a ∼3 cGy/h selection dose rate, where uncorrected survival relative to normal cells is lower by a factor of 50-150. Colonies recovered will provide valuable information regarding the genetic nature of their radiosensitivity (possibly involving chromosome stability, DNA repair, and/or cell cycle regulatory pathways), that may influence risks for cancer and heritable effects for a previously

  17. Effect of 17-AAG on radio-sensitivity of HeLa and V79 cells

    International Nuclear Information System (INIS)

    Pan Yanling; Hong Chengjiao; Zhang Baoguo

    2010-01-01

    In order to investigate the radio-sensitizing effect of 17-AAG, an inhibitor of Heat Shock Protein 90, on human Uterine Cervix Cancer HeLa and V79 cells, Clonogenic assay was used to observe the cell survival rate. The results show that 17-AAG can decrease obviously (p 0.05). This indicates that 17-AAG may enhance the radio-sensitivity of the HeLa cell line and has no effect on the V79 cell line. (authors)

  18. Prospective study evaluating the radiosensitizing effect of reduced doses of temozolomide in the treatment of Egyptian patients with glioblastoma multiforme

    Directory of Open Access Journals (Sweden)

    Gaber M

    2013-10-01

    Full Text Available May Gaber, Hanan Selim, Tamer El-NahasDepartment of Clinical Oncology, Cairo University, Cairo, EgyptPurpose: In view of the documented toxicity of continuous daily radiosensitizer doses of temozolomide concomitant with radiation in the treatment of glioblastoma multiforme, we aimed to compare it with a different schedule of abbreviated radiosensitizer dosing.Patients and methods: This was a randomized prospective study comparing toxicity and survival in 60 Egyptian patients with glioblastoma multiforme. Patients in arm I received temozolomide at a dose of 75 mg/m2 daily with radiotherapy for 42 days, starting 4 weeks after surgery and reaching to a total radiation dose of 60 Gy/30 Fractions/6 weeks, while patients in arm II received temozolomide at a dose of 75 mg/m2 concomitantly with the same radiotherapy schedule daily in the first and last weeks of the same radiotherapy program.Results: Common grade 1–2 adverse events were malaise in 28 patients (46.7%, followed by alopecia (40% and nausea (26.7%. Grade 3–4 convulsion and decreased level of consciousness was seen in only four patients who were all from arm I. The median progression-free survival (PFS for the entire study population was 10.6 months (95% confidence interval [CI] 7.3–14, and PFS at 12 months was 32%. The median PFS in arm I was 8.8 months (95% CI 5.9–11.7 and in arm II 11.5 months (95% CI 8.9–14.2, and PFS at 12 months for both arms was 32% and 30% respectively (P=0.571. The median overall survival (OS of the whole group of patients was 14.2 months (95% CI 13–15.5, and OS was 70% at 12 months and 25% at 18 months. The median OS for patients in arm I was 12.3 months (95% CI 7.7–16.9, whereas in arm II it was 14.3 months (95% CI 14–14.7 (P=0.83.Conclusion: Reduced radiosensitizer dosing of temozolomide concomitant with radiotherapy in glioblastoma multiforme exhibited comparable efficacy with a classic continuous daily schedule, though with better tolerability

  19. Radiobiological characteristics of cervical cancer

    International Nuclear Information System (INIS)

    Kagabu, Teruo; Kobayashi, Takashi; Nanayama, Kunihiko

    1976-01-01

    In order to observe the radiobiological characteristics of cervical cancer, the author carried out irradiation of 60 Co in 16 cases of cervical cancer. The primary lesion of each case was exposed to radiation of 100 R once a day, 40 times in sequence, totaling 4,000 R. To evaluate this results, the vaginal smears were obtained everyday and examined for changes in cancerous cells caused by the irradiation. The results of our study showed that cervical cancer could be classified into three groups according to the radiosensitivity of its cancerous cells. In the group of low-radiosensitivity (11 cases of 16), the cancerous cells decreased gradually, and enlargement of the nuclei of the cancerous cells was observed from 2,000 R of irradiation, but the majority of the cancerous cells were those of nucleus after the irradiation of 4,000 R. In all of the 5 uterus removed, residual cancer lesion was noted. The radiocuability was unfavourable. In the group of high-radiosensitivity (4 cases of 16), the cancerous cells decreased remarkablly. Enlargement of nucleus was noted from 1,000 R of the irradiation, the cancerous cells of small-sized nucleus appeared with the irradiation of 3,000 R but the cancerous cells almost disappeared with the irradiation of 4,000 R. The radiocuability was favourable. In the group of combination of high-radiosensitivity and low-radiosensitivity portions (one case of 16), the cancerous cells decreased remarkablly until the exposure to the radiation of 2,000 R but thereafter did slowly. In a removed uterus, the cancer lesion was noted, but the prognosis was favourable. The foregoing results suggest that changes in the nuclear diameter of the cancerous cells in vaginal smears during irradiation can tell the radiosensitivity of the cancerous cells. (Kanao, N.)

  20. Radiosensitivity of cancer-initiating cells and normal stem cells (or what the Heisenberg uncertainly principle has to do with biology).

    Science.gov (United States)

    Woodward, Wendy Ann; Bristow, Robert Glen

    2009-04-01

    Mounting evidence suggests that parallels between normal stem cell biology and cancer biology may provide new targets for cancer therapy. Prospective identification and isolation of cancer-initiating cells from solid tumors has promoted the descriptive and functional identification of these cells allowing for characterization of their response to contemporary cancer therapies, including chemotherapy and radiation. In clinical radiation therapy, the failure to clinically eradicate all tumor cells (eg, a lack of response, partial response, or nonpermanent complete response by imaging) is considered a treatment failure. As such, biologists have explored the characteristics of the small population of clonogenic cancer cells that can survive and are capable of repopulating the tumor after subcurative therapy. Herein, we discuss the convergence of these clonogenic studies with contemporary radiosensitivity studies that use cell surface markers to identify cancer-initiating cells. Implications for and uncertainties regarding incorporation of these concepts into the practice of modern radiation oncology are discussed.

  1. Cutaneous cancer and xeroderma pigmentosum; Cancer cutane et xeroderma pigmentosum

    Energy Technology Data Exchange (ETDEWEB)

    Ben Salah, H.; Bahri, M.; Mnejja, W.; Siala, W.; Daoud, J. [Centre Hospitalier Universitaire Habib-Bourguiba, Service de Radiotherapie Carcinologique, Sfax (Tunisia); Sallemi, T. [Centre Hospitalier Universitaire Habib-Bourguiba, Service d' Anatomie Pathologique, Sfax (Tunisia); Turki, H. [Centre Hospitalier Universitaire Habib-Bourguiba, Service de Dermatologie, Sfax (Tunisia)

    2007-11-15

    The cutaneous cancer at the patients affected by xeroderma pigmentosum is characterized by its multifocal character and its strong radiosensitivity. A premature care and a regular follow-up for life of these patients is indispensable for the detection and the treatment of new hurts. The precautionary measures are also important by the school eviction. (N.C.)

  2. Genistein, a tyrosine kinase inhibitor, enhanced radiosensitivity in human esophageal cancer cell lines in vitro: Possible involvement of inhibition of survival signal transduction pathways

    International Nuclear Information System (INIS)

    Akimoto, Tetsuo; Nonaka, Tetsuo; Ishikawa, Hitoshi; Sakurai, Hideyuki; Saitoh, Jun-ichi; Takahashi, Takeo; Mitsuhashi, Norio

    2001-01-01

    Purpose: The effect of genistein, a tyrosine kinase inhibitor, on radiosensitivity was examined, especially focusing on 'survival signal transduction pathways'. Methods and Materials: Two human esophageal squamous cell cancer cell lines, TE-1 (p53, mutant) and TE-2 (p53, wild), were used. Radiosensitivity was determined by clonogenic assay, and activation of survival signals was examined by Western blot. Results: Genistein (30 μM) greatly enhanced radiosensitivity in these cell lines by suppressing radiation-induced activation of survival signals, p42/p44 extracellular signal-regulated kinase and AKT/PKB. Significant increase in the percentage of apoptotic cells and increased poly[ADP-ribose] polymerase cleavage were observed in TE-2, but not in TE-1 even after combination of genistein with irradiation. In terms of changes in expression of p53-related proteins, increase in expression of Bax and decrease in that of Bcl-2 were observed in TE-2 but not in TE-1, suggesting that the main mode of cell death induced by genistein in a cell line with wild type p53 differed from that with mutant p53. Conclusions: This study suggested that survival signals, including p42/p44 ERK and AKT/PKB, may be involved in determining radiosensitivity, and genistein would be a potent therapeutic agent that has an enhancing effect on radiation

  3. Radiosensitization by the histone deacetylase inhibitor vorinostat under hypoxia and with capecitabine in experimental colorectal carcinoma

    Directory of Open Access Journals (Sweden)

    Saelen Marie

    2012-09-01

    Full Text Available Abstract Background The histone deacetylase inhibitor vorinostat is a candidate radiosensitizer in locally advanced rectal cancer (LARC. Radiosensitivity is critically influenced by hypoxia; hence, it is important to evaluate the efficacy of potential radiosensitizers under variable tissue oxygenation. Since fluoropyrimidine-based chemoradiotherapy (CRT is the only clinically validated regimen in LARC, efficacy in combination with this established regimen should be assessed in preclinical models before a candidate drug enters clinical trials. Methods Radiosensitization by vorinostat under hypoxia was studied in four colorectal carcinoma cell lines and in one colorectal carcinoma xenograft model by analysis of clonogenic survival and tumor growth delay, respectively. Radiosensitizing effects of vorinostat in combination with capecitabine were assessed by evaluation of tumor growth delay in two colorectal carcinoma xenografts models. Results Under hypoxia, radiosensitization by vorinostat was demonstrated in vitro in terms of decreased clonogenicity and in vivo as inhibition of tumor growth. Adding vorinostat to capecitabine-based CRT increased radiosensitivity of xenografts in terms of inhibited tumor growth. Conclusions Vorinostat sensitized colorectal carcinoma cells to radiation under hypoxia in vitro and in vivo and improved therapeutic efficacy in combination with capecitabine-based CRT in vivo. The results encourage implementation of vorinostat into CRT in LARC trials.

  4. Estimation of absorbed dose of radiosensitive organs and effective sose in patients underwent abdominopelvic spiral CT scan using impact CT patient dosimetry

    Directory of Open Access Journals (Sweden)

    Ayoub Amirnia

    2017-05-01

    Full Text Available Background: Due to the presence of radiosensitive organs in the abdominopelvic region and increasing the number of requests for CT scan examinations, concerns about increasing radiation doses in patients has been greatly elevated. Therefore, the goal of this study was to determine the absorbed dose of radiosensitive organs and the effective dose in patients underwent abdominopelvic CT scan using ImPACT CT patient dosimetry Calculator (version 1.0.4, Imaging Performance Assessment on Computed Tomography, www.impactscan.org. Methods: This prospective cross-sectional study was conducted in Imam Reza Hospital from November to February 2015 February 2015 in the Imam Reza Hospital, in Urmia, Iran. The demographic and dosimetric information of 100 patients who underwent abdominopelvic CT scan in a 6-slice CT scanner were obtained through the data collection forms. The demographic data of the patients included age, weight, gender, and BMI. The dosimetric parameters included pitch value, CT dose volume index (CTDIvol, dose-length product (DLP, tube voltage, tube current, exposure time, collimation size, scan length, and scan time. To determine the absorbed dose of radiosensitive organs and also the effective dose in patients, ImPACT CT patient dosimetry calculator was used. Results: The results of this study demonstrated that the mean and standard deviation (SD of patients' effective dose in abdominopelvic CT scan was 4.927±0.164 mSv. The bladder in both genders had the greatest mean organ dose, which was 64.71±17.15 mGy for men and 77.56±18.48 mGy for women (P<0.001. Conclusion: The effective dose values of this examination are in the same range as previous studies, as well as International Commission on Radiological Protection (ICRP recommendations. However, the radiation dose from CT scan has the largest contribution to the medical imaging. According to the ALARA principle, it is recommended that the scan parameters, especially mAs, should be

  5. Evaluation of combination effects of 2-methoxyoestradiol and methoxyamine on IUdR-induced radiosensitization in glioma spheroids

    International Nuclear Information System (INIS)

    Neshasteh-Riz, A.; Babaloui, S.; Khoei, S.

    2010-01-01

    Glioblastoma is the most common and most malignant cancer of central nervous system. Targeted radiotherapy is an effective method toward its treatment. Iododeoxyuridine (IUdR) is a halogenated thymidine analogue known to be effective as a radiosensitizer in human cancer therapy. In this study we have evaluated the combination effects of 2-Methoxyoestradiol, an inhibitor of hypoxia inducible factor 1α (HIF-1α) and Methoxyamine, an inhibitor of base excision repair pathway on radiosensitization of Iododeoxyuridine in glioblastoma spheroid culture. Materials and Methods: The cytotoxic damages of DNA in U87MG cell line were compared using colony formation assay. Experiments were performed in large spheroids with a diameter of approximately 350μm. Results: Evaluation of the effects of Iododeoxyuridine with 2ME2 and MX pretreatment on spheroid cultured cell followed by ionizing irradiation showed more enhancemented (p≤0.001) Iododeoxyuridine induced-radiosensitization. These results introduced a key role for 2ME2 in Iododeoxyuridine related studies. Conclusion: Pretreatment of tumor cells with Iododeoxyuridine, MX and 2ME2 before Irradiation enhances tumor radiosensitization and may improve therapeutic index for Iododeoxyuridine and 2ME2.

  6. A randomized double-blind phase III study of nimorazole as a hypoxic radiosensitizer of primary radiotherapy in supraglottic larynx and pharynx carcinoma. Results of the Danish Head and Neck Cancer Study (DAHANCA) Protocol 5-85

    DEFF Research Database (Denmark)

    Overgaard, J.; Hansen, H.S.; Overgaard, M.

    1998-01-01

    PURPOSE: A multicenter randomized and balanced double-blind trial with the objective of assessing the efficacy and tolerance of nimorazole given as a hypoxic radiosensitizer in conjunction with primary radiotherapy of invasive carcinoma of the supraglottic larynx and pharynx. PATIENTS AND TREATMENT...... for the end-points of final loco-regional control (including surgical salvage) and cancer-related deaths (52 versus 41%, P = 0.002). This trend was also found in the overall survival but to a lesser, non-significant extent (26 versus 16%, 10-year actuarial values, P = 0.32). Cox multivariate regression...... of dying from cancer. The compliance to radiotherapy was good and 98% of the patients received the planned dose. Late radiation-related morbidity was observed in 10% of the patients, irrespective of nimorazole treatment. Drug-related side-effects were minor and tolerable with transient nausea and vomiting...

  7. Re-evaluation of in vitro radiosensitivity of human fibroblasts of different genetic origins

    Energy Technology Data Exchange (ETDEWEB)

    Deschavanne, P.J.; Debieu, D.; Malaise, E.P.; Fertil, B.

    1986-08-01

    Statistical analysis of the radiosensitivity of 204 survival curves of non-transformed human fibroblast cell strains of different genetic origins was made using the multi-target one-hit model (characterized by parameters eta and D/sub 0/), the surviving fraction for a 2 Gy dose (S/sub 2/) and the mean inactivation dose (D-bar). D-bar is found to be the parameter for characterization of anomalous radiosensitivity linked to a genetic disorder and discrimination between groups of cell strains of differing radiosensitivity. It allows the description of a range of 'normal' radiosensitivity for control fibroblasts and classification of genetic disorders as a function of their mean radiosensitivity expressed in terms of D-bar. Nine groups of cell strains appear to exhibit radiosensitivity differing significantly from the controls: seven groups are hypersensitive (ataxia-telengiectasia homozygotes and heterozygotes, Cockayne's syndrome, Gardner's syndrome, 5-oxoprolinuria homozygotes and heterozygotes, Fanconi's anaemia) and two groups are more radioresistant (fibroblasts from retinoblastoma patients and individuals with chromosome 13 anomalies). Since the coupled parameter eta and D/sub 0/ failed to discriminate between the radiosensitivity of the different genetic groups, the use of D-bar to make an intercomparison of intrinsic radiosensitivity of non-transformed human fibroblasts is recommended. (U.K.).

  8. Re-evaluation of in vitro radiosensitivity of human fibroblasts of different genetic origins

    International Nuclear Information System (INIS)

    Deschavanne, P.J.; Debieu, D.; Malaise, E.P.; Fertil, B.

    1986-01-01

    Statistical analysis of the radiosensitivity of 204 survival curves of non-transformed human fibroblast cell strains of different genetic origins was made using the multi-target one-hit model (characterized by parameters eta and D 0 ), the surviving fraction for a 2 Gy dose (S 2 ) and the mean inactivation dose (D-bar). D-bar is found to be the parameter for characterization of anomalous radiosensitivity linked to a genetic disorder and discrimination between groups of cell strains of differing radiosensitivity. It allows the description of a range of 'normal' radiosensitivity for control fibroblasts and classification of genetic disorders as a function of their mean radiosensitivity expressed in terms of D-bar. Nine groups of cell strains appear to exhibit radiosensitivity differing significantly from the controls: seven groups are hypersensitive (ataxia-telengiectasia homozygotes and heterozygotes, Cockayne's syndrome, Gardner's syndrome, 5-oxoprolinuria homozygotes and heterozygotes, Fanconi's anaemia) and two groups are more radioresistant (fibroblasts from retinoblastoma patients and individuals with chromosome 13 anomalies). Since the coupled parameter eta and D 0 failed to discriminate between the radiosensitivity of the different genetic groups, the use of D-bar to make an intercomparison of intrinsic radiosensitivity of non-transformed human fibroblasts is recommended. (U.K.)

  9. Radiosensitizers: rationale and potential

    International Nuclear Information System (INIS)

    Brown, J.M.

    1981-01-01

    This paper briefly reviews agents that are capable of sensitizing hypoxic cells to radiation and chemotherapeutic agents. The first part is a synopsis of the development of hypoxic radiosensitizers, which concludes that misonidazole can be effective against human tumors. Unfortunately, neurotoxicity limits its effectiveness in humans because the dose that can be given in conjunction with daily fractionated radiation is five to ten times lower than is required for full radiosensitization of the hypoxic cells. The second part covers our recent efforts to develop a drug that does not produce such limiting neurotoxicity. The primary rationale of our program was to synthesize a drug with a short plasma half-life that was too hydrophilic to cross the blood-brain barrier but was able to penetrate tumors and radiosensitize hypoxic cells. From this program, a new drug, SR-2508, has been found that is as efficient as misonidazole in its radiosensitizing ability, but is four to ten times less toxic. Finally, the potential of radiosensitizers not only as agents that can sensitize tumor cells to radiation, but also as agents that can specifically sensitize tumors to chemotherapeutic agents, is discussed. In addition, these drugs may be potential cytotoxic agents that produce toxicity only in solid tumors

  10. Radiosensitizing Effects of Ectopic miR-101 on Non–Small-Cell Lung Cancer Cells Depend on the Endogenous miR-101 Level

    International Nuclear Information System (INIS)

    Chen, Susie; Wang Hongyan; Ng, Wooi Loon; Curran, Walter J.; Wang Ya

    2011-01-01

    Purpose: Previously, we showed that ectopic miR-101 could sensitize human tumor cells to radiation by targeting ATM and DNA-PK catalytic subunit (DNA-PKcs) to inhibit DNA repair, as the endogenous miR-101 levels are low in tumors in general. However, the heterogeneity of human cancers may result in an exception. The purpose of this study was to test the hypothesis that a few tumor cell lines with a high level of endogenous miR-101 would prove less response to ectopic miR-101. Methods and Materials: Fourteeen non–small-cell lung cancer (NSCLC) cell lines and one immortalized non-malignant lung epithelial cell line (NL20) were used for comparing endogenous miR-101 levels by real-time reverse transcription–polymerase chain reaction. Based on the different miR-101 levels, four cell lines with different miR-101 levels were chosen for transfection with a green fluorescent protein–lentiviral plasmid encoding miR-101. The target protein levels were measured by using Western blotting. The radiosensitizing effects of ectopic miR-101 on these NSCLC cell lines were determined by a clonogenic assay and xenograft mouse model. Results: The endogenous miR-101 level was similar or lower in 13 NSCLC cell lines but was 11-fold higher in one cell line (H157) than in NL20 cells. Although ectopic miR-101 efficiently decreased the ATM and DNA-PKcs levels and increased the radiosensitization level in H1299, H1975, and A549 cells, it did not change the levels of the miR-101 targets or radiosensitivity in H157 cells. Similar results were observed in xenograft mice. Conclusions: A small number of NSCLC cell lines could have a high level of endogenous miR-101. The ectopic miR-101 was able to radiosensitize most NSCLC cells, except for the NSCLC cell lines that had a much higher endogenous miR-101 level. These results suggest that when we choose one miRNA as a therapeutic tool, the endogenous level of the miRNA in each tumor should be considered.

  11. Radiosensitizing Effects of Ectopic miR-101 on Non-Small-Cell Lung Cancer Cells Depend on the Endogenous miR-101 Level

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Susie; Wang Hongyan; Ng, Wooi Loon; Curran, Walter J. [Department of Radiation Oncology, School of Medicine and the Winship Cancer Institute, Emory University, Atlanta, GA (United States); Wang Ya, E-mail: ywang94@emory.edu [Department of Radiation Oncology, School of Medicine and the Winship Cancer Institute, Emory University, Atlanta, GA (United States)

    2011-12-01

    Purpose: Previously, we showed that ectopic miR-101 could sensitize human tumor cells to radiation by targeting ATM and DNA-PK catalytic subunit (DNA-PKcs) to inhibit DNA repair, as the endogenous miR-101 levels are low in tumors in general. However, the heterogeneity of human cancers may result in an exception. The purpose of this study was to test the hypothesis that a few tumor cell lines with a high level of endogenous miR-101 would prove less response to ectopic miR-101. Methods and Materials: Fourteeen non-small-cell lung cancer (NSCLC) cell lines and one immortalized non-malignant lung epithelial cell line (NL20) were used for comparing endogenous miR-101 levels by real-time reverse transcription-polymerase chain reaction. Based on the different miR-101 levels, four cell lines with different miR-101 levels were chosen for transfection with a green fluorescent protein-lentiviral plasmid encoding miR-101. The target protein levels were measured by using Western blotting. The radiosensitizing effects of ectopic miR-101 on these NSCLC cell lines were determined by a clonogenic assay and xenograft mouse model. Results: The endogenous miR-101 level was similar or lower in 13 NSCLC cell lines but was 11-fold higher in one cell line (H157) than in NL20 cells. Although ectopic miR-101 efficiently decreased the ATM and DNA-PKcs levels and increased the radiosensitization level in H1299, H1975, and A549 cells, it did not change the levels of the miR-101 targets or radiosensitivity in H157 cells. Similar results were observed in xenograft mice. Conclusions: A small number of NSCLC cell lines could have a high level of endogenous miR-101. The ectopic miR-101 was able to radiosensitize most NSCLC cells, except for the NSCLC cell lines that had a much higher endogenous miR-101 level. These results suggest that when we choose one miRNA as a therapeutic tool, the endogenous level of the miRNA in each tumor should be considered.

  12. Novel Single-Nucleotide Polymorphism Markers Predictive of Pathologic Response to Preoperative Chemoradiation Therapy in Rectal Cancer Patients

    International Nuclear Information System (INIS)

    Kim, Jin C.; Ha, Ye J.; Roh, Seon A.; Cho, Dong H.; Choi, Eun Y.; Kim, Tae W.; Kim, Jong H.; Kang, Tae W.; Kim, Seon Y.; Kim, Yong S.

    2013-01-01

    Purpose: Studies aimed at predicting individual responsiveness to preoperative chemoradiation therapy (CRT) are urgently needed, especially considering the risks associated with poorly responsive patients. Methods and Materials: A 3-step strategy for the determination of CRT sensitivity is proposed based on (1) the screening of a human genome-wide single-nucleotide polymorphism (SNP) array in correlation with histopathologic tumor regression grade (TRG); (2) clinical association analysis of 113 patients treated with preoperative CRT; and (3) a cell-based functional assay for biological validation. Results: Genome-wide screening identified 9 SNPs associated with preoperative CRT responses. Positive responses (TRG 1-3) were obtained more frequently in patients carrying the reference allele (C) of the SNP CORO2A rs1985859 than in those with the substitution allele (T) (P=.01). Downregulation of CORO2A was significantly associated with reduced early apoptosis by 27% (P=.048) and 39% (P=.023) in RKO and COLO320DM colorectal cancer cells, respectively, as determined by flow cytometry. Reduced radiosensitivity was confirmed by colony-forming assays in the 2 colorectal cancer cells (P=.034 and .015, respectively). The SNP FAM101A rs7955740 was not associated with radiosensitivity in the clinical association analysis. However, downregulation of FAM101A significantly reduced early apoptosis by 29% in RKO cells (P=.047), and it enhanced colony formation in RKO cells (P=.001) and COLO320DM cells (P=.002). Conclusion: CRT-sensitive SNP markers were identified using a novel 3-step process. The candidate marker CORO2A rs1985859 and the putative marker FAM101A rs7955740 may be of value for the prediction of radiosensitivity to preoperative CRT, although further validation is needed in large cohorts

  13. Clinical experience with intravenous radiosensitizers in unresectable sarcomas

    International Nuclear Information System (INIS)

    Kinsella, T.J.; Glatstein, E.

    1987-01-01

    Traditionally, adult bone and soft tissue sarcomas have been considered to be ''radioresistant.'' Because of this philosophy, patients who present with locally advanced, unresectable sarcomas often are treated in a palliative fashion, usually with low-dose radiotherapy. Over the last 6 years, 29 patients with unresectable primary or metastatic sarcomas were treated using a combination of intravenous chemical radiosensitizers and high-dose irradiation. Twenty-two of 29 patients achieved clinical local control, with six patients having a complete clinical response. The time to tumor response is often several months or longer, which is in contrast to other tumor histologies (carcinomas, lymphomas), where tumor response usually occurs over several weeks. Several large tumors have shown only a minimal tumor response, yet were found to be sterilized in posttreatment biopsy or autopsy examination. Of 15 patients with primary sarcomas without metastases, 11 patients (73%) remain free of local tumor progression from 12 to 83 months. Adult high-grade sarcomas can be controlled with high-dose radiotherapy and intravenous radiosensitizers, although the precise role of these agents is unclear

  14. Brain metastasis in human epidermal growth factor receptor 2-positive breast cancer: from biology to treatment

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Tae Ryool [Dept. of Radiation Oncology, Hallym University Chuncheon Sacred Heart Hospital, Chuncheon (Korea, Republic of); Kim, In Ah [Dept. of Radiation Oncology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

    2016-03-15

    Overexpression of human epidermal growth factor receptor 2 (HER2) is found in about 20% of breast cancer patients. With treatment using trastuzumab, an anti-HER2 monoclonal antibody, systemic control is improved. Nonetheless, the incidence of brain metastasis does not be improved, rather seems to be increased in HER2-positive breast cancer. The mainstay treatment for brain metastases is radiotherapy. According to the number of metastatic lesions and performance status of patients, radiosurgery or whole brain radiotherapy can be performed. The concurrent use of a radiosensitizer further improves intracranial control. Due to its large molecular weight, trastuzumab has a limited ability to cross the blood-brain barrier. However, small tyrosine kinase inhibitors such as lapatinib, has been noted to be a promising agent that can be used as a radiosensitizer to affect HER2-positive breast cancer. This review will outline general management of brain metastases and will focus on preclinical findings regarding the radiosensitizing effect of small molecule HER2 targeting agents.

  15. Hyperthermia enhances radiosensitivity of colorectal cancer cells through ROS inducing autophagic cell death.

    Science.gov (United States)

    Ba, Ming-Chen; Long, Hui; Wang, Shuai; Wu, Yin-Bing; Zhang, Bo-Huo; Yan, Zhao-Fei; Yu, Fei-Hong; Cui, Shu-Zhong

    2018-04-01

    Hyperthermia (HT) enhances the anti-cancer effects of radiotherapy (RT), but the precise biochemical mechanisms involved are unclear. This study was aim to investigate if mild HT sensitizes colorectal cancer cells to RT through reactive oxygen species (ROS)-inducing autophagic cell death in a mice model of HCT116 human colorectal cancer. HCT116 mice model were randomly divided into five groups: mock group, hyperthermia group (HT), radiotherapy group (RT), HT + RT group, and HT + RT +N-acetyl L-cysteine (NAC) group (HT + CT + NAC). After four weeks of treatment, cancer growth inhibition, rate and mitochondrial membrane potential were measured with MTT and JC-1 assays, respectively, while ROS were estimated fluorimetrically. The relationship of these parameters to expressions of autophagy-related genes Beclin1, LC3B, and mTOR was analyzed. Gene expression was measured by Real-Time polymerase chain reaction (RT-PCR). There were significant increases in ROS levels and mitochondrial membrane potential in the HT + RT group. ROS levels in the HT + RT group increased more significantly than in any other group. In contrast, ROS levels in the HT + RT + NAC group were significantly decreased relative to the HT + RT group. The number of autophagic bodies in HT + RT group was higher than that of mock group. There were significant increases in the expression of Beclin1 and LC3B genes, while mTOR expression was significantly decreased in the HT + CT group. Treatment with NAC reversed the pattern of these changes. These results indicate that HT enhances the radiosensitivity of colorectal cancer cells to RT through ROS inducing autophagic cell death. © 2017 Wiley Periodicals, Inc.

  16. Pharmacokinetics of metronidazole and its effect on the body during its use as a radiosensitizer

    International Nuclear Information System (INIS)

    Zel'vin, B.M.; Polyakov, P.Yu.; Zimina, E.S.; Dar'yalova, S.L.; Kiseleva, E.S.; Sokolova, I.I.

    1984-01-01

    During gamma-beam therapy (40-60 Gy) a study was made of the content of metronidazole (MZ) in the blood of 20 patients with oral mucosa cancer and 12 patients with esophageal cancer devending on a mode of its administration. A MZ effect on liver apd renal fUnction was studied. MZ was administered to the patients with cancer of both sites on the first 3 days of radiation therapy 3 h before an enlarged fraction of 4 Gy, estimated at 145 mg per 1 kg body mass (8-10 g) per os or via a gastrostoma and 15 h in rectal administration. In the patients with oral mucosa cancer after the administration of MZ per os its level which was sufficient for radiosensitization, was achieved after 2 h and remained for subsequent 4 h with maximum accumulation of 262-+22 μg/ml in the blood serum 3-4 h after administration. In the patients with esophageal cancer after MZ administration via the gastrostoma, the nature and time course of drug accumulation in the blood was identical, however accumulation maximum was lower and reached 219+-25 μg/ml. In the patients with esophageal cancer after MZ rectal administration, its level in the blood was 118 μg/ml only and did not achieve a therapeutically effective level. It is assumed that the lowering of MZ repeated dose by 20% will cause a decrease in the drug accumulation in the body and the degree of a toxic effect with maintaining its therapeutically effective level in the blood and tumor

  17. Radiosensitization by hematocrit manipulation

    International Nuclear Information System (INIS)

    Hirst, D.G.; Hazlehurst, J.L.; Brown, J.M.

    1985-01-01

    The authors show that tumors in mice adapt to anemia in a rather complex manner. Radiosensitivity may be lower, higher or equal to normal depending on when the anemia is induced prior to irradiation. The authors study these changes in radiosensitivity which occur during a period of anemia followed by the restoration of the hematocrit. When mice were made anemic immediately before irradiation, their tumors were very resistant, but the resistance was lost over the following 24 hrs even though the anemia was maintained. If mice which had been anemic for 24 hrs were retransfused to normal levels with red blood cells immediately before irradiation, their tumors were considerably more sensitive than normal. As the interval between retransfusion and irradiation was increased, sensitization was rapidly lost so that by 24 hrs sensitivity was the same as that of control tumors. They attribute this loss of sensitization to rapid tumor growth in response to a restored oxygen supply so that new hypoxic cells are created. The implications of this for the treatment of the anemic patient are discussed

  18. Doranidazole (PR-350), a hypoxic cell radiosensitizer, radiosensitizes human lung tumors (RERF-LC- AI) and causes changes in tumor oxygenation

    International Nuclear Information System (INIS)

    Kubota, N.; Griffin, R.J.; Williams, B.W.; Song, C.W.; Yahiro, T.

    2003-01-01

    Full text: We previously have reported the radiosensitizing capability of Doranidazole (PR-350) on SCCVII cells and tumors (Puerto Rico, 2001). In the present study, we have investigated the efficacy of PR-350 as a hypoxic cell radiosensitizer using human lung cancer cells (RERF-LC-AI) in vitro and also RERF-LC-AI tumors grown s.c. in Balb/c nude mice. Using the micronucleus assay method, we determined the effect of PR-350 on the response of RERF-LC-AI cells to radiation under hypoxic conditions and enhancement ratios (ER) of 1.45∼2.26 were obtained. The in vivo radiosensitizing effect was studied by irradiating RERF-LC-AI tumors with 15 Gy at 20 min. after i.v. injection of PR-350 (200mg/kg) and measuring the tumor growth delay. Significant growth delay occurred after i.v. injection of PR-350 before irradiation compared to radiation alone. We measured tumor pO 2 at 3, 7 and 14 days after treatment using an Eppendorf pO 2 histograph. The frequency of pO 2 values 2 in tumors treated with radiation plus PR-350 were higher than that in tumors treated with radiation plus saline. These data suggest that the O 2 consumption in tumors treated with radiation plus PR-350 was less than that in tumors treated with radiation plus saline due to greater drug and radiation-induced cell death. This hypothesis is supported by the fact that the tumor size in the combined treatment group was smaller than in radiation alone. These results suggest that PR-350 may improve the response of tumors to radiotherapy not only by increasing the radiosensitivity of hypoxic cells but also by improving tumor oxygenation over many days during fractionated radiotherapy

  19. Radiosensitivity of grapevines. Empirical modelling of the radiosensitivity of some clones to x-ray irradiation. Pt. 1

    International Nuclear Information System (INIS)

    Koeroesi, F.; Jezierska-Szabo, E.

    1999-01-01

    Empirical and formal (Poisson) models were utilized, applying experimental growth data to characterize the radiosensitivity of six grapevine clones to X-ray irradiation. According to the radiosensitivity constants (k), target numbers (n) and volumes, GR 37 doses and energy deposition, the following radiosensitivity order has been found for various vine brands: Chardonnay clone type < Harslevelue K. 9 < Koevidinka K. 8 < Muscat Ottonel clone type < Irsai Oliver K. 11 < Cabernet Sauvignon E. 153. The model can be expanded to describe the radiosensitivity of other plant species and varieties, and also the efficiency of various radioprotecting agents and conditions. (author)

  20. Ectopic expression of miR-34a enhances radiosensitivity of non-small cell lung cancer cells, partly by suppressing the LyGDI signaling pathway

    International Nuclear Information System (INIS)

    Duan Weiming; Xu Yaxiang; Dong Yujin; Cao Lili; Tong Jian; Zhou Xinwen

    2013-01-01

    miR-34a is transcriptionally induced by the tumor suppressor gene p53, which is often downregulated in non-small cell lung cancer (NSCLC). To address whether the downstream signal of miR-34a is sufficient to induce apoptosis and to alter cellular radiosensitivity, a chemical synthetic miR-34a mimic was delivered into A549 and H1299 cells, with or without co-treatment of γ-irradiation. Results showed that ectopic expression of miR-34a induced dose-dependent cell growth inhibition and apoptosis in a p53-independent manner in both NSCLC cell lines. Interestingly, LyGDI was discovered as a new target gene of miR-34a, and downregulation of LyGDI promoted Rac1 activation and membrane translocation, resulting in cell apoptosis. Furthermore, restoration of miR-34a indirectly reduced cyclooxygenase-2 (COX-2) expression. Taken together, these results demonstrate that restoration of miR-34a expression enhances radiation-induced apoptosis, partly by suppressing the LyGDI signaling pathway, and miR-34a could possibly be used as a radiosensitizer for non-small cell lung cancer therapy. (author)

  1. Lack of dependence of 5-fluorodeoxyuridine-mediated radiosensitization on cytotoxicity

    International Nuclear Information System (INIS)

    Lawrence, T.S.; Davis, M.A.; Chang, E.Y.

    1995-01-01

    It has been proposed that fluoropyrimidine-mediated cytotoxicity and radiosensitization are closely correlated. We have shown that HT29 human colon cancer cells transfected with the E. coli dUTPase gene are resistant to 5-fluorodeoxyuridine (FdUrd)-mediated cytotoxicity, presumably through more effective elimination of dUTP. We used these cells to assess the association between radiosensitization and cytotoxicity produced by FdUrd. The radiation sensitivities of the clones expressing elevated dUTPase activity (dutE clones) were similar to those of untransfected HT29 cells or HT29 cells which has been transfected with only the expression vector for the E. coli gene (con clones). We found that FdUrd produced similar increases in radiation sensitivity regardless of dUTPase activity. Levels of dUTPase in the dutE clones remained elevated during the entire period of FdUrd exposure, demonstrating that the lack of difference between dutE and Con clones was not a reflection of down-regulation of dUTPase activity by FdUrd, Flow cytometry showed that all clones progressed past the G 1 /S-phase boundary and into early S phase during FdUrd treatment. These data suggest that the mechanisms of FdUrd-mediated cytotoxicity and radiosensitization are not closely linked. These findings, combined with our previous investigations, are consistent with the hypothesis that radiosensitization occurs in cells which progress past the G 1 /S-phase boundary in the presence of FdUrd. 24 refs., 2 figs., 2 tabs

  2. Detection of individual radiosensitivity by radiation–induced micronuclei in human peripheral blood lymphocytes and polymorphisms in DNA repair genes

    Energy Technology Data Exchange (ETDEWEB)

    Staynova, A.; Hadjidekova, V.; Popova, L.; Hristova, R. [Radiation Genetics Laboratory, National Centre of Radiobology and Radiation Protection, Sofia (Bulgaria); Savov, A. [National Genetic Laboratory, University Hospital of Obstetrics and Gynecology, Sofia (Bulgaria)

    2013-07-01

    Aim: To investigate the association of two polymorphisms – in XRCC1 gene (Arg399Gln) and in APE1 gene (Asp148Glu) and the radiation induced frequency of micronuclei in human peripheral blood lymphocytes. Material and methods: Genomic DNA from 34 cancer patients and 52 controls were genotyped using PCR–RFLP technique. Micronucleus test (MNT) was performed on 15 cancer patients and 15 controls, before and after in vitro irradiation with 2Gy gamma rays. Results: The data showed that cancer patients had a significantly higher spontaneous frequency of cells with micronuclei than controls (P=0.009). No statistical difference was registered when comparing the mean frequency of cells with micronuclei after in vitro irradiation between these groups. Four subjects were selected as radiosensitive after applying cut–off of the mean frequency of radiation induced micronuclei. Three of them are carriers of the XRCC1 399Gln allele and two of them are carriers of the APE1 148Glu allele. (author)

  3. Sympathoadrenal and hypophyseal-adrenal systems in preoperative irradiation of patients with esophageal and cardiac cancer

    International Nuclear Information System (INIS)

    Tarutinov, V.I.; Starosel'skij, I.V.; Gol'dshmidt, B.Ya.; Shmal'ko, Yu.P.; Levchenko, A.M.

    1983-01-01

    A study was made of 74 patients with esophageal and cardiac cancer. Stages 3 and 4. The excretion of catecholamines, corticosteroids and their precursors was studied, tests with adrenalin before and after preoperative irradiation at a summary dose of 30 Gy were done. It has been shown that before the start of radiation therapy the excretion of catecholamines and corticosteroids is lowered, the reaction to adrenalin administration is negative in most patients, the phase syndrome of cardiac hypodynamics associated with disturbed function of the sympathoadrenal system was revealed. Preoperative irradiation in patients with esophageal and cardiac cancer results in an incres ased excretion of 17-ketosteroids (17-KS) and 17-ketogenic steroids, however 17-KS excretion does not reach the normal level. For better tolerance of irradiation and for a radiosensitization effect testenate is administered to patients before and during radiation therapy. The administration of testenate 7-10 days before the start and during radiotherapy proved to be effective Which was confirmed by noticeable necrobiotic and necrotic changes of cancer cells

  4. Skin test of radiosensitivity. Application to Fanconi anemia

    International Nuclear Information System (INIS)

    Dutreix, J.; Gluckman, E.

    1983-01-01

    A test of skin radiosensitivity is described. It is achieved by irradiating small skin fields (15 mm in diameter) with 50 kV X-rays. The radiosensitivity is evaluated from the skin reaction observed for a single acute dose of 8 and 10 Gy; it is considered increased if the reaction for 10 Gy exceeds the desquamation threshold, and scored according to the observed reaction. The test includes an evaluation of the cellular repair, assessed on the comparison of the reactions for single dose and split irradiation. The time of the reaction peak is also reported. Abnormal reactions have been observed on 4 out of 8 patients with Fanconi Anemia

  5. Skin test of radiosensitivity. Application to Fanconi anemia

    Energy Technology Data Exchange (ETDEWEB)

    Dutreix, J. (Institut Gustave-Roussy, 94 - Villejuif (France)); Gluckman, E. (Centre Hayem, Hopital St.-Louis, 75 Paris (France))

    1983-01-01

    A test of skin radiosensitivity is described. It is achieved by irradiating small skin fields (15 mm in diameter) with 50 kV X-rays. The radiosensitivity is evaluated from the skin reaction observed for a single acute dose of 8 and 10 Gy; it is considered increased if the reaction for 10 Gy exceeds the desquamation threshold, and scored according to the observed reaction. The test includes an evaluation of the cellular repair, assessed on the comparison of the reactions for single dose and split irradiation. The time of the reaction peak is also reported. Abnormal reactions have been observed on 4 out of 8 patients with Fanconi Anemia.

  6. Toxicity Profile and Pharmacokinetic Study of A Phase I Low-Dose Schedule-Dependent Radiosensitizing Paclitaxel Chemoradiation Regimen for Inoperable Non-Small-Cell Lung Cancer

    International Nuclear Information System (INIS)

    Chen, Yuhchyau; Pandya, Kishan J.; Feins, Richard; Johnstone, David W.; Watson, Thomas; Smudzin, Therese; Keng, Peter C.

    2008-01-01

    Purpose: We report the toxicity profile and pharmacokinetic data of a schedule-dependent chemoradiation regimen using pulsed low-dose paclitaxel for radiosensitization in a Phase I study for inoperable non-small-cell lung cancer. Methods and Materials: Paclitaxel at escalating doses of 15 mg/m 2 , 20 mg/m 2 , and 25 mg/m 2 were infused on Monday, Wednesday, and Friday with daily chest radiation in cohorts of 6 patients. Daily radiation was delayed for maximal G2/M arrest and apoptotic effect, an observation from preclinical investigations. Plasma paclitaxel concentration was determined by high-performance liquid chromatography. Results: Dose-limiting toxicities included 3 of 18 patients with Grade 3 pneumonitis and 3 of 18 patients with Grade 3 esophagitis. There was no Grade 4 or 5 pneumonitis or esophagitis. There was also no Grade 3 or 4 neutropenia, thrombocytopenia, anemia or neuropathy. For Dose Levels I (15 mg/m 2 ), II (20 mg/m 2 ), and III (25 mg/m 2 ), the mean peak plasma level was 0.23 ± 0.06 μmol/l, 0.32 ± 0.05 μmol/l, and 0.52 ± 0.14 μmol/l, respectively; AUC was 0.44 ± 0.09 μmol/l, 0.61 ± 0.1 μmol/l, and 0.96 ± 0.23 μmol/l, respectively; and duration of drug concentration >0.05 μmol/l (t > 0.05 μmol/l) was 1.6 ± 0.3 h, 1.9 ± 0.2 h, and 3.0 ± 0.9 h, respectively. Conclusion: Pulsed low-dose paclitaxel chemoradiation is associated with low toxicity. Pharmacokinetic data showed that plasma paclitaxel concentration >0.05 μmol/l for a minimum of 1.6 h was sufficient for effective radiosensitization

  7. Cutaneous cancer and xeroderma pigmentosum

    International Nuclear Information System (INIS)

    Ben Salah, H.; Bahri, M.; Mnejja, W.; Siala, W.; Daoud, J.; Sallemi, T.; Turki, H.

    2007-01-01

    The cutaneous cancer at the patients affected by xeroderma pigmentosum is characterized by its multifocal character and its strong radiosensitivity. A premature care and a regular follow-up for life of these patients is indispensable for the detection and the treatment of new hurts. The precautionary measures are also important by the school eviction. (N.C.)

  8. Wound healing morbidity in STS patients treated with preoperative radiotherapy in relation to in vitro skin fibroblast radiosensitivity, proliferative capacity and TGF-β activity

    International Nuclear Information System (INIS)

    Akudugu, John M.; Bell, Robert S.; Catton, Charles; Davis, Aileen M.; Griffin, Anthony M.; O'Sullivan, Brian; Waldron, John N.; Ferguson, Peter C.; Wunder, Jay S.; Hill, Richard P.

    2006-01-01

    Background and purpose: In a recent study, we demonstrated that the ability of dermal fibroblasts, obtained from soft tissue sarcoma (STS) patients, to undergo initial division in vitro following radiation exposure correlated with the development of wound healing morbidity in the patients following their treatment with preoperative radiotherapy. Transforming growth factor beta (TGF-β) is thought to play an important role in fibroblast proliferation and radiosensitivity both of which may impact on wound healing. Thus, in this study we examined the interrelationship between TGF-β activity, radiosensitivity and proliferation of cultured fibroblasts and the wound healing response of STS patients after preoperative radiotherapy to provide a validation cohort for our previous study and to investigate mechanisms. Patients and methods: Skin fibroblasts were established from skin biopsies of 46 STS patients. The treatment group consisted of 28 patients who received preoperative radiotherapy. Eighteen patients constituted a control group who were either irradiated postoperatively or did not receive radiation treatment. Fibroblast cultures were subjected to the colony forming and cytokinesis-blocked binucleation assays (low dose rate: ∼0.02 Gy/min) and TGF-β assays (high dose-rate: ∼1.06 Gy/min) following γ-irradiation. Fibroblast radiosensitivity and initial proliferative ability were represented by the surviving fraction at 2.4 Gy (SF 2.4 ) and binucleation index (BNI), respectively. Active and total TGF-β levels in fibroblast cultures were determined using a biological assay. Wound healing complication (WHC), defined as the requirement for further surgery or prolonged deep wound packing, was the clinical endpoint examined. Results: Of the 28 patients treated with preoperative radiotherapy, 8 (29%) had wound healing difficulties. Fibroblasts from patients who developed WHC showed a trend to retain a significantly higher initial proliferative ability after

  9. Integration of Principles of Systems Biology and Radiation Biology: Toward Development of in silico Models to Optimize IUdR-Mediated Radiosensitization of DNA Mismatch Repair Deficient (Damage Tolerant) Human Cancers

    International Nuclear Information System (INIS)

    Kinsella, Timothy J.; Gurkan-Cavusoglu, Evren; Du, Weinan; Loparo, Kenneth A.

    2011-01-01

    Over the last 7 years, we have focused our experimental and computational research efforts on improving our understanding of the biochemical, molecular, and cellular processing of iododeoxyuridine (IUdR) and ionizing radiation (IR) induced DNA base damage by DNA mismatch repair (MMR). These coordinated research efforts, sponsored by the National Cancer Institute Integrative Cancer Biology Program (ICBP), brought together system scientists with expertise in engineering, mathematics, and complex systems theory and translational cancer researchers with expertise in radiation biology. Our overall goal was to begin to develop computational models of IUdR- and/or IR-induced base damage processing by MMR that may provide new clinical strategies to optimize IUdR-mediated radiosensitization in MMR deficient (MMR − ) “damage tolerant” human cancers. Using multiple scales of experimental testing, ranging from purified protein systems to in vitro (cellular) and to in vivo (human tumor xenografts in athymic mice) models, we have begun to integrate and interpolate these experimental data with hybrid stochastic biochemical models of MMR damage processing and probabilistic cell cycle regulation models through a systems biology approach. In this article, we highlight the results and current status of our integration of radiation biology approaches and computational modeling to enhance IUdR-mediated radiosensitization in MMR − damage tolerant cancers.

  10. Efficacy of radiosensitizing doped titania nanoparticles under hypoxia and preparation of an embolic microparticle

    Directory of Open Access Journals (Sweden)

    Morrison RA

    2017-05-01

    Full Text Available Rachel A Morrison,1,* Malgorzata J Rybak-Smith,1,* James M Thompson,2 Bénédicte Thiebaut,3 Mark A Hill,2 Helen E Townley1,4 1Department of Engineering Science, 2Gray Laboratories, CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, 3Johnson Matthey, Technology Centre, Reading, Berkshire, 4Nuffield Department of Obstetrics and Gynaecology, John Radcliffe Hospital, University of Oxford, Oxford, UK *These authors have contributed equally to this work Abstract: The aim of this study was to develop a manufacturing protocol for large-scale production of doped titania radiosensitizing nanoparticles (NPs to establish their activity under hypoxia and to produce a multimodal radiosensitizing embolic particle for cancer treatment. We have previously shown that radiosensitizing NPs can be synthesized from titania doped with rare earth elements, especially gadolinium. To translate this technology to the clinic, a crucial step is to find a suitable, scalable, high-throughput method. Herein, we have described the use of flame spray pyrolysis (FSP to generate NPs from titanium and gadolinium precursors to produce titania NPs doped with 5 at% gadolinium. The NPs were fully characterized, and their capacity to act as radiosensitizers was confirmed by clonogenic assays. The integrity of the NPs in vitro was also ascertained due to the potentially adverse effects of free gadolinium in the body. The activity of the NPs was then studied under hypoxia since this is often a barrier to effective radiotherapy. In vitro radiosensitization experiments were performed with both the hypoxia mimetics deferoxamine and cobalt chloride and also under true hypoxia (oxygen concentration of 0.2%. It was shown that the radiosensitizing NPs were able to cause a significant increase in cell death even after irradiation under hypoxic conditions such as those found in tumors. Subsequently, the synthesized NPs were used to modify polystyrene embolization

  11. Studies of serial serum electrophoretic pattern for prognosis in various cancer patients during irradiation

    International Nuclear Information System (INIS)

    Ra, Woo Youn; Woo, Won Hyung

    1971-01-01

    During the period from June. 1969 to Dec. 1970, the serum protein electrophoretic patterns of 44 cases of various cancer patients have been studied to determine the alterations in serum protein fractions in patients who were responding to irradiation or those failing. The serum electrophoretic pattern could be observed as an indicator of prognosis or radiosensitivity. A blood sample was obtained prior to any treatment and the follow up sampling was performed 2 times during radiation therapy. Serum total protein was determined by the method of Wolfson and serum electrophoresis was carried out by using Spinoco Model R B electrophoresis system. The results were following: Seven cases out of cases of cervical cancer responding favorably to radiotherapy showed decreased in Alpha-2 globulin fraction were increased. A case whose third time serum electrophoretic pattern showed multiple myeloma type died 5 months after radiotherapy with bone metastasis. Four cases out of 9 cases of favorably responded breast cancer patients showed decreased in Alpha-2 globulin foraction compared with 2 cases of unfavorable response showed increased in Alpha-2 globulin fraction

  12. Studies of serial serum electrophoretic pattern for prognosis in various cancer patients during irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ra, Woo Youn; Woo, Won Hyung [Kyungpook National University School of Medicine, Taegu (Korea, Republic of)

    1971-10-15

    During the period from June. 1969 to Dec. 1970, the serum protein electrophoretic patterns of 44 cases of various cancer patients have been studied to determine the alterations in serum protein fractions in patients who were responding to irradiation or those failing. The serum electrophoretic pattern could be observed as an indicator of prognosis or radiosensitivity. A blood sample was obtained prior to any treatment and the follow up sampling was performed 2 times during radiation therapy. Serum total protein was determined by the method of Wolfson and serum electrophoresis was carried out by using Spinoco Model R B electrophoresis system. The results were following: Seven cases out of cases of cervical cancer responding favorably to radiotherapy showed decreased in Alpha-2 globulin fraction were increased. A case whose third time serum electrophoretic pattern showed multiple myeloma type died 5 months after radiotherapy with bone metastasis. Four cases out of 9 cases of favorably responded breast cancer patients showed decreased in Alpha-2 globulin foraction compared with 2 cases of unfavorable response showed increased in Alpha-2 globulin fraction.

  13. Roscovitine strongly enhances the effect of olaparib on radiosensitivity for HPV neg. but not for HPV pos. HNSCC cell lines.

    Science.gov (United States)

    Ziemann, Frank; Seltzsam, Steve; Dreffke, Kristin; Preising, Stefanie; Arenz, Andrea; Subtil, Florentine S B; Rieckmann, Thorsten; Engenhart-Cabillic, Rita; Dikomey, Ekkehard; Wittig, Andrea

    2017-12-01

    At present, advanced stage human Papillomavirus (HPV) negative and positive head and neck squamous cell carcinoma (HNSCC) are treated by intense multimodal therapy that includes radiochemotherapy, which are associated with relevant side effects. Patients with HPV positive tumors possess a far better prognosis than those with HPV negative cancers. Therefore, new therapeutic strategies are needed to improve the outcome especially of the latter one as well as quality of life for all HNSCC patients. Here we tested whether roscovitine, an inhibitor of cyclin-dependent kinases (CDKs), which hereby also blocks homologous recombination (HR), can be used to enhance the radiation sensitivity of HNSCC cell lines. In all five HPV negative and HPV positive cell lines tested, roscovitine caused inhibition of CDK1 and 2. Surprisingly, all HPV positive cell lines were found to be defective in HR. In contrast, HPV negative strains demonstrated efficient HR, which was completely suppressed by roscovitine. In line with this, for HPV negative but not for HPV positive cell lines, treatment with roscovitine resulted in a pronounced enhancement of the radiation-induced G2 arrest as well as a significant increase in radiosensitivity. Due to a defect in HR, all HPV positive cell lines were efficiently radiosensitized by the PARP-1 inhibitor olaparib. In contrast, in HPV negative cell lines a significant radiosensitization by olaparib was only achieved when combined with roscovitine.

  14. Radio-induced malignancies after breast cancer postoperative radiotherapy in patients with Li-Fraumeni syndrome

    International Nuclear Information System (INIS)

    Heymann, Steve; Bourgier, Céline; Delaloge, Suzette; Rahal, Arslane; Caron, Olivier; Frebourg, Thierry; Barreau, Lise; Pachet, Corinne; Mathieu, Marie-Christine; Marsiglia, Hugo

    2010-01-01

    There are no specific recommendations for the management of breast cancer patients with germ-line p53 mutations, an exceptional genetic condition, particularly regarding postoperative radiotherapy. Preclinical data suggested that p53 mutations conferred enhanced radiosensitivity in vitro and in vivo and the few clinical observations showed that Li-Fraumeni families were at a higher risk of secondary radio-induced malignancies. We reviewed a cohort of patients with germ-line p53 mutations who had been treated for breast cancer as the first tumor event. We assessed their outcome and the incidence of secondary radio-induced malignancies. Among 47 documented Li-Fraumeni families treated from 1997 to 2007 at the Institut Gustave Roussy, 8 patients had been diagnosed with breast cancer as the first tumor event. Three patients had undergone conservative breast surgery followed by postoperative radiotherapy and five patients had undergone a mastectomy (3 with postoperative radiotherapy). Thus, 6/8 patients had received postoperative radiotherapy. Median follow-up was 6 years. Median age at the diagnosis of the primary breast cancer was 30 years. The histological characteristics were as follows: intraductal carcinoma in situ (n = 3), invasive ductal carcinoma (n = 4) and a phyllodes tumor (n = 1). Among the 6 patients who had received adjuvant radiotherapy, the following events had occurred: 3 ipsilateral breast recurrences, 3 contralateral breast cancers, 2 radio-induced cancers, and 3 new primaries (1 of which was an in-field thyroid cancer with atypical histology). In contrast, only one event had occurred (a contralateral breast cancer) among patients who had not received radiation therapy. These observations could argue in favor of bilateral mastectomy and the avoidance of radiotherapy

  15. Phase I/II Trial of Sequential Chemoradiotherapy Using a Novel Hypoxic Cell Radiosensitizer, Doranidazole (PR-350), in Patients With Locally Advanced Non-Small-Cell Lung Cancer (WJTOG-0002)

    International Nuclear Information System (INIS)

    Nishimura, Yasumasa; Nakagawa, Kazuhiko; Takeda, Koji; Tanaka, Masahiro; Segawa, Yoshihiko; Tsujino, Kayoko; Negoro, Shunichi; Fuwa, Nobukazu; Hida, Toyoaki; Kawahara, Masaaki; Katakami, Nobuyuki; Hirokawa, Keiko; Yamamoto, Nobuyuki; Fukuoka, Masahiro; Ariyoshi, Yutaka

    2007-01-01

    Purpose: This Phase I/II trial was conducted to assess the efficacy and safety of PR-350, a novel hypoxic cell radiosensitizer, when administered with thoracic radiation therapy (RT) after induction chemotherapy (CT) for locally advanced non-small-cell lung cancer (NSCLC). Methods and Materials: Two cycles of cisplatin (80 mg/m 2 ) and paclitaxel (180 mg/m 2 ), or carboplatin (AUC = 6) and paclitaxel (200 mg/m 2 ) were given before RT of 60 Gy in 30 fractions. In the Phase I portion, the starting dosage of PR-350 was 10 daily administrations (2000 mg/m 2 ) in combination with RT, and this number was increased in increments of 10 for successive groups to 30 doses. Results: In total, 37 patients were enrolled. In Phase I (n = 20), PR-350 could be administered 30 times with concurrent thoracic RT. Thus, in Phase II (n = 17), PR-350 was administered 30 times. The major toxicity was radiation pneumonitis, with Grade 3 or more pneumonitis noted in 6 patients (16%) including 2 with treatment-related deaths. However, no Grade 3 or more esophageal toxicity was noted, and only Grade 1 peripheral neuropathy was noted in 9 patients (24%). For all 37 patients, the median survival time (MST) and the 2-year survival rate were 15.9 months and 24%, respectively. For 18 patients receiving 21 to 30 doses of PR-350, the MST and 2-year survival rate were 20.9 months and 33%, respectively. Conclusions: Thoracic RT combined with 30 daily administrations of PR-350 after induction CT was well tolerated and promising for locally advanced NSCLC

  16. Reduction of nitric oxide level enhances the radiosensitivity of hypoxic non-small cell lung cancer

    International Nuclear Information System (INIS)

    Saleem, Wael; Suzuki, Yoshiyuki; Mobaraki, Abdulelah; Yoshida, Yukari; Noda, Shinei; Saitoh, Jun-ichi; Nakano, Takashi

    2011-01-01

    The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (E-TKI) resistance has emerged as an important clinical issue. To overcome this resistance, researchers have examined different modalities, either for use as a monotherapy or in combination with E-TKI therapy. In the present study, we investigated whether a decrease in nitric oxide (NO) levels affects the radiosensitization of non-small cell lung cancer (NSCLC) cell lines. A549 and H3255 NSCLC cells were examined. They were subjected to hypoxic conditions and monotherapy, or combined therapy using radiation and N G -monomethyl- L -arginine, monoacetate (LNMMA). Reductions in nitric oxide levels enhanced the radiosensitivity of both cell lines and significantly reduced the expression of both hypoxia-inducible factor-1α (HIF-1α) and EGFR in H3255 cells compared to A549 cells. Since NO is significantly associated with cell metabolism, we measured the levels of pyruvate dehydrogenase kinase-1 (PDK-1), reactive oxygen species, and oxygen and observed that the expression of PDK-1 was significantly reduced. This reduction was seen simultaneously after the silencing of HIF-1α; however, not following LNMMA treatment. The oxygen concentration was significantly increased in the treated cells, and their viability decreased in parallel. Reactive oxygen species were decreased after LNMMA and radiation treatment. Adding EGFR-TKI to cells with reduced NO levels further suppressed cell viability when combined with radiation. This study suggests that a reduction in the NO level might substantially overcome the radioresistance of mutant NSCLC cells. (author)

  17. How far is cancer cured by radiation sensitization?

    International Nuclear Information System (INIS)

    Ando, Koichi; Sasaki, Takehito; Ikeda, Hiroshi

    1990-01-01

    Some types of cancer are not cured by radiation alone in view of histology, location, and size. In facing so-called radioresistant cancer, antineoplastic agents, hypoxic cell sensitizers, biological response modifiers, or hyperthermia are used in combination with radiation, with the aim of cancer cure. First of all, this chapter discusses the subject of 'what is tumor cure by radiation therapy'. Current conditions of the aforementioned combined modalities and the future perspectives are presented. The following subjects are covered: (1) tumor control - significance of the number of stem cells; (2) biological evaluation of chemo-radiotherapy with cisplatin; (3) clinical results and experience with combination of radiotherapy and radiosensitizers; (4) radiosensitization with hypoxic cell radiosensitizers - present status (5) hypoxic cell radiosensitizers - present status and problems from the viewpoint of clinical radiotherapy; (6) thermal radiosensitization in vitro and its implications for radiotherapy; (7) clinical assessment of thermoradiotherapy for breast cancer and cancer of the urinary bladder; (8) interactions of radiation and biological response modifiers in the treatment of malignant tumor; (9) improvement in the effects of radiation therapy with biological response modifiers. (N.K.)

  18. Biochemical evidence for deficient DNA repair leading to enhanced G2 chromatid radiosensitivity and susceptibility to cancer

    International Nuclear Information System (INIS)

    Gantt, R.; Parshad, R.; Price, F.M.; Sanford, K.K.

    1986-01-01

    Human tumor cells and cells from cancer-prone individuals, compared with those from normal individuals, show a significantly higher incidence of chromatid breaks and gaps seen in metaphase cells immediately after G2 X irradiation. Previous studies with DNA repair-deficient mutants and DNA repair inhibitors strongly indicate that the enhancement results from a G2 deficiency(ies) in DNA repair. We report here biochemical evidence for a DNA repair deficiency that correlates with the cytogenetic studies. In the alkaline elution technique, after a pulse label with radioactive thymidine in the presence of 3-acetylaminobenzamide (a G2-phase blocker) and X irradiation, DNA from tumor or cancer-prone cells elutes more rapidly during the postirradiation period than that from normal cells. These results indicate that the DNA of tumor and cancer-prone cells either repairs more slowly or acquires more breaks than that of normal cells; breaks can accumulate during incomplete or deficient repair processes. The kinetic difference between normal and tumor or cancer-prone cells in DNA strand-break repair reaches a maximum within 2 h, and this maximum corresponds to the kinetic difference in chromatid aberration incidence following X irradiation reported previously. These findings support the concept that cells showing enhanced G2 chromatid radiosensitivity are deficient in DNA repair. The findings could also lead to a biochemical assay for cancer susceptibility

  19. Profound radiosensitivity in leukemic T-cell lines and T-cell-type acute lymphoblastic leukemia demonstrated by sodium [51Cr]chromate labeling

    International Nuclear Information System (INIS)

    Nakazawa, S.; Minowada, J.; Tsubota, T.; Sinks, L.F.

    1978-01-01

    Radiation sensitivity was determined by measuring spontaneous release from 51 Cr-labeled cells in various lymphoid cell populations. Among six leukemia T-cell lines originating from acute lymphoblastic leukemia, four such lines were found to be highly radiosensitive. In contrast, two of the leukemic T-cell lines and four normal control B-cell lines were not radiosensitive. Thymocytes from six patients and leukemia T-cell blasts from three patients with T-cell leukemia were likewise found to be highly radiosensitive, whereas leukemic blasts from six patients with null-cell (non-T, non-B-cell) acute lymphoblastic leukemia were not radiosensitive. Normal peripheral blood lymphocytes and mitogen-induced normal lymphoblasts were found not to be radiosensitive. The results indicate that measurement of the radiation sensitivity of acute leukemic blasts may have a therapeutic significance in coping with the heterogeneous nature of individual leukemia cases

  20. Andrographolide impedes cancer stemness and enhances radio-sensitivity in oral carcinomas via miR-218 activation.

    Science.gov (United States)

    Yang, Po-Yu; Hsieh, Pei-Ling; Wang, Tong Hong; Yu, Cheng-Chia; Lu, Ming-Yi; Liao, Yi-Wen; Lee, Tzu-Hsin; Peng, Chih-Yu

    2017-01-17

    Current evidence suggests that oral cancer stem cells (OCSCs) possess high tumorigenic and metastatic properties as well as chemo- and radioresistance. In this study, we demonstrated that andrographolide, the main bioactive component in the medicinal plant Andrographis, significantly reduced oncogenicity and restored radio-sensitivity of ALDH1+CD44+ OCSCs. Mechanistic studies showed that andrographolide treatment increased the expression of microRNA-218 (miR-218), leading to the downregulation of Bmi1. We showed that knockdown of miR-218 in ALDH1-CD44- non-OCSCs enhanced cancer stemness, while silencing of Bmi1 significantly counteracted it. Furthermore, we found tumor growth was reduced in mice bearing xenograft tumors after andrographolide treatment via activation of miR-218/Bmi1 axis. Together, these data demonstrated that the inhibition of tumor aggressiveness in OCSCs by andrographolide was mediated through the upregulation of miR-218, thereby reducing Bmi1 expression. These findings suggest that andrographolide may be a valuable natural compound for anti-CSCs treatment of OSCC.

  1. Comparative radiosensitivity in the class insecta

    International Nuclear Information System (INIS)

    Willard, W.K.; Cherry, D.S.

    1975-01-01

    A 'radiosensitivity index' (LT 50 /mean longevity) was correlated with the mean longevity and dry weight of 37 insect species (both sexes of 12 species) representing eight orders. Curvilinear regression analysis relating radiosensitivity to mean longevity and mean dry weight indicated that 46.3% of the observed variation could be attributed to longevity and 32.6% to the dry weight of the species. In general, large long-lived adults were more radiosensitive than small short-lived adults. Correlation of the phylogeny of insect orders and order groupings with the radio-sensitivity index was found to be poor. However, when the index was related to longevity, there was a tendency for species comprising the major orders investigated to occur in groups along the predicted curve. (author)

  2. Potentiation of radiosensitivity by tetrandrine in human breast cancer cells and its mechanism

    International Nuclear Information System (INIS)

    Sun Xinchen; Zhen Yongsu; Shao Rongguang; Wang Junjie

    2003-01-01

    Objective: To investigate the potentiation of radiosensitivity and mechanism by tetrandrine (Tet) in human breast cancer p53-mutant MCF-7/ADR and p53-wt MCF-7 cells. Methods: Clonogenic assay, flow cytometry, Western blotting were preformed in this experiment. Results: The data of clonogenic assay showed that Tet markedly sensitized MCF-7/ADR cell to X-rays, and the sensitization enhancement ratio (SER) of Tet was 1.51. Flow cytometry assay showed that exposure of MCF-7/ADR cells to X-rays caused cells to arrest in G 2 phase, whereas Tet was able to lower the number of cells arrested in G 2 phase. However, in MCF-7 cells, the potentiation effect of Tet was lower, and its SER was 1.10. MCF-7 cells were induced to arrest in G 1 and G 2 phases by X-rays, and the number of cells arrested in G 2 phase abrogated by Tet was less than that in MCF-7/ADR cells. Furthermore, the results showed that the levels of Cyclin B1 and Cdc2 expression decreased after X-irradiation, and the mitotic index was lower too. Tet could reverse this decrease and induce X-ray-irradiated cells to enter mitosis. Conclusion: Tet is a potent G 2 checkpoint abrogator and markedly enhances the cytotoxicity of X irradiation in the p53-mutant cancer cells

  3. miR-21 modulates resistance of HR-HPV positive cervical cancer cells to radiation through targeting LATS1

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Shikai; Song, Lili, E-mail: commasll@163.com; Zhang, Liang; Zeng, Saitian; Gao, Fangyuan

    2015-04-17

    Although multiple miRNAs are found involved in radioresistance development in HR-HPV positive (+) cervical cancer, only limited studies explored the regulative mechanism of the miRNAs. miR-21 is one of the miRNAs significantly upregulated in HR-HPV (+) cervical cancer is also significantly associated with radioresistance. However, the detailed regulative network of miR-21 in radioresistance is still not clear. In this study, we confirmed that miR-21 overexpression was associated with higher level of radioresistance in HR-HPV (+) cervical cancer patients and thus decided to further explore its role. Findings of this study found miR-21 can negatively affect radiosensitivity of HR-HPV (+) cervical cancer cells and decrease radiation induced G2/M block and increase S phase accumulation. By using dual luciferase assay, we verified a binding site between miR-21 and 3′-UTR of large tumor suppressor kinase 1 (LATS1). Through direct binding, miR-21 can regulate LATS1 expression in cervical cancer cells. LATS1 overexpression can reverse miR-21 induced higher colony formation rate and also reduced miR-21 induced S phase accumulation and G2/M phase block reduction under radiation treatment. These results suggested that miR-21-LATS1 axis plays an important role in regulating radiosensitivity. - Highlights: • miR-21 is highly expressed in HR-HPV (+) radioresistant cervical cancer patients. • miR-21 can negatively affect radiosensitivity of HR-HPV (+) cervical cancer cells. • miR-21 can decrease radiation induced G2/M block and increase S phase accumulation. • miR-21 modulates radiosensitivity cervical cancer cell by directly targeting LATS1.

  4. miR-21 modulates resistance of HR-HPV positive cervical cancer cells to radiation through targeting LATS1

    International Nuclear Information System (INIS)

    Liu, Shikai; Song, Lili; Zhang, Liang; Zeng, Saitian; Gao, Fangyuan

    2015-01-01

    Although multiple miRNAs are found involved in radioresistance development in HR-HPV positive (+) cervical cancer, only limited studies explored the regulative mechanism of the miRNAs. miR-21 is one of the miRNAs significantly upregulated in HR-HPV (+) cervical cancer is also significantly associated with radioresistance. However, the detailed regulative network of miR-21 in radioresistance is still not clear. In this study, we confirmed that miR-21 overexpression was associated with higher level of radioresistance in HR-HPV (+) cervical cancer patients and thus decided to further explore its role. Findings of this study found miR-21 can negatively affect radiosensitivity of HR-HPV (+) cervical cancer cells and decrease radiation induced G2/M block and increase S phase accumulation. By using dual luciferase assay, we verified a binding site between miR-21 and 3′-UTR of large tumor suppressor kinase 1 (LATS1). Through direct binding, miR-21 can regulate LATS1 expression in cervical cancer cells. LATS1 overexpression can reverse miR-21 induced higher colony formation rate and also reduced miR-21 induced S phase accumulation and G2/M phase block reduction under radiation treatment. These results suggested that miR-21-LATS1 axis plays an important role in regulating radiosensitivity. - Highlights: • miR-21 is highly expressed in HR-HPV (+) radioresistant cervical cancer patients. • miR-21 can negatively affect radiosensitivity of HR-HPV (+) cervical cancer cells. • miR-21 can decrease radiation induced G2/M block and increase S phase accumulation. • miR-21 modulates radiosensitivity cervical cancer cell by directly targeting LATS1

  5. Computed Tomography Demonstration of the Production and Distribution of Oxygen Gas Following Intratumoral Injection of a New Radiosensitizer (KORTUC) for Patients with Breast Cancer-Is Intratumoral Injection Not an Ideal Approach to Solve the Major Problem of Tumor Hypoxia in Radiotherapy?

    Science.gov (United States)

    Hayashi, Naoya; Ogawa, Yasuhiro; Kubota, Kei; Okino, Kazuhiro; Akima, Ryo; Morita-Tokuhiro, Shiho; Tsuzuki, Akira; Yaogawa, Shin; Nishioka, Akihito; Miyamura, Mitsuhiko

    2016-04-01

    We previously developed a new enzyme-targeting radiosensitization treatment named Kochi Oxydol-Radiation Therapy for Unresectable Carcinomas, Type II (KORTUC II), which contains hydrogen peroxide and sodium hyaluronate for injection into various types of tumors. For breast cancer treatment, the radiosensitization agent was injected into the tumor tissue twice a week under ultrasonographic guidance, immediately prior to each administration of radiation therapy. At approximately three hours after the second or third injection, computed tomography (CT) was performed to confirm the production and distribution of oxygen gas generated from the KORTUC radiosensitization agent by catalysis of peroxidases contained mainly in tumor tissue. The purpose of this study was to demonstrate that tumor hypoxia could be overcome by such a procedure and to evaluate the method of intratumoral injection in terms of confirming oxygen distribution in the target tumor tissue and around the tumor to be visualized on dedicated CT imaging. Three-dimensional reconstructed maximum intensity projection imaging of contrast-enhanced breast magnetic resonance imaging was used to compare the position of the tumor and that of the generated oxygen. Distributed oxygen gas was confirmed in the tumor tissue and around it in all 10 patients examined in the study. A region of oxygen gas was measured as an average value of -457.2 Hounsfield units (HU) as a region of interest. A slightly increased HU value compared to the density of air or oxygen was considered due to the presence of tumor tissue in the low-density area on 5-mm-thick reconstructed CT imaging. The results of this study showed that intratumoral oxygen was successfully produced by intratumoral KORTUC injection under ultrasonographic guidance, and that tumor hypoxia, which is considered a main cause of radioresistance in currently used Linac (linear accelerator) radiation therapy for malignant neoplasms, could be resolved by this method.

  6. Quercetin suppresses DNA double-strand break repair and enhances the radiosensitivity of human ovarian cancer cells via p53-dependent endoplasmic reticulum stress pathway

    Directory of Open Access Journals (Sweden)

    Gong C

    2017-12-01

    Full Text Available Cheng Gong,1 Zongyuan Yang,1 Lingyun Zhang,2 Yuehua Wang,2 Wei Gong,2 Yi Liu3 1Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 2Department of Oncology, XiangYang Central Hospital, Hubei University of Arts and Science, XiangYang, 3Department of Medicinal Chemistry, School of Pharmacy, Hubei University of Chinese Medicine, Wuhan, China Abstract: Quercetin is proven to have anticancer effects for many cancers. However, the role of tumor suppressor p53 on quercetin’s radiosensitization and regulation of endoplasmic reticulum (ER stress response in this process remains obscure. Here, quercetin exposure resulted in ER stress, prolonged DNA repair, and the expression of p53 protein; phosphorylation on serine 15 and 20 increased in combination with X-irradiation. Quercetin pretreatment could potentiate radiation-induced cell death. The combination of irradiation and quercetin treatment aggravated DNA damages and caused typical apoptotic cell death; as well the expression of Bax and p21 elevated and the expression of Bcl-2 decreased. Knocking down of p53 could reverse all the above effects under quercetin in combination with radiation. In addition, quercetin-induced radiosensitization was through stimulation of ATM phosphorylation. In human ovarian cancer xenograft model, combined treatment of quercetin and radiation significantly restrained the growth of tumors, accompanied with the activation of p53, CCAAT/enhancer-binding protein homologous protein, and γ-H2AX. Overall, these results indicated that quercetin acted as a promising radiosensitizer through p53-dependent ER stress signals. Keywords: quercetin, p53, endoplasmic reticulum stress, DNA double-strand breaks, eIF-2α (eukaryotic initiation factor 2α, ATM kinase

  7. Radiosensitivity of amphibia

    Energy Technology Data Exchange (ETDEWEB)

    Muramatsu, S [National Inst. of Radiological Sciences, Chiba (Japan)

    1975-04-01

    Radiosensitivity (semi-lethal dose) and the damages of radiation in the amphibia were studied by /sup 3/H-TdR from the standpoint of cellular kinetics. The cell mitosis cycle of the amphibia required a long time. The functional cell regeneration and the physiological function of the cell were slower than in mice. The reason for the low radiosensitivity of the amphibia was discussed relative to the environmental factor of temperature. Because the amphibia change body temperature according to environmental temperature, the danger of radiation damage, the actual lethal dose and the period of survival were influenced by the environmental temperature. Acute radiation danger to amphibia was essentially the same as the danger to mammalia, both young and old. LD/sub 50/ irradiation effects varied among the species. The cell regeneration, turn over, and the mitosis in the amphibia, were affected by environmental temperature, however, the courses proceeded slower than those of the mammalia. Therefore, the question remains, whether the comparison of the radiosensitivities of amphibia with other classes of animal by LDsub(50/30) irradiation was appropriate.

  8. Epigenetic Regulation of KLHL34 Predictive of Pathologic Response to Preoperative Chemoradiation Therapy in Rectal Cancer Patients

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Ye J. [Department of Surgery, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Institute of Innovative Cancer Research and Asan Institute for Life Sciences, Asan Medical Center, Seoul (Korea, Republic of); Kim, Chan W. [Department of Surgery, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Roh, Seon A. [Department of Surgery, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Institute of Innovative Cancer Research and Asan Institute for Life Sciences, Asan Medical Center, Seoul (Korea, Republic of); Cho, Dong H. [Institute of Innovative Cancer Research and Asan Institute for Life Sciences, Asan Medical Center, Seoul (Korea, Republic of); Graduate School of East-West Medical Science, Kyung Hee University, Gyeonggi-do (Korea, Republic of); Park, Jong L.; Kim, Seon Y. [Medical Genomics Research Center, Korea Research Institute of Bioscience & Biotechnology, Daejeon (Korea, Republic of); Kim, Jong H. [Department of Radiation Oncology, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Choi, Eun K. [Department of Radiation Oncology, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Institute of Innovative Cancer Research and Asan Institute for Life Sciences, Asan Medical Center, Seoul (Korea, Republic of); Kim, Yong S., E-mail: yongsung@kribb.re.kr [Medical Genomics Research Center, Korea Research Institute of Bioscience & Biotechnology, Daejeon (Korea, Republic of); Institute of Innovative Cancer Research and Asan Institute for Life Sciences, Asan Medical Center, Seoul (Korea, Republic of); Kim, Jin C., E-mail: jckim@amc.seoul.kr [Department of Surgery, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Institute of Innovative Cancer Research and Asan Institute for Life Sciences, Asan Medical Center, Seoul (Korea, Republic of)

    2015-03-01

    Purpose: Prediction of individual responsiveness to preoperative chemoradiation therapy (CRT) is urgently needed in patients with poorly responsive locally advanced rectal cancer (LARC). Methods and Materials: Candidate methylation genes associated with radiosensitivity were identified using a 3-step process. In the first step, genome-wide screening of methylation genes was performed in correlation with histopathologic tumor regression grade in 45 patients with LARC. In the second step, the methylation status of selected sites was analyzed by pyrosequencing in 67 LARC patients, including 24 patients analyzed in the first step. Finally, colorectal cancer cell clones with stable KLHL34 knockdown were generated and tested for cellular sensitivity to radiation. Results: Genome-wide screening identified 7 hypermethylated CpG sites (DZIP1 cg24107021, DZIP1 cg26886381, ZEB1 cg04430381, DKK3 cg041006961, STL cg00991794, KLHL34 cg01828474, and ARHGAP6 cg07828380) associated with preoperative CRT responses. Radiosensitivity in patients with hypermethylated KLHL34 cg14232291 was confirmed by pyrosequencing in additional cohorts. Knockdown of KLHL34 significantly reduced colony formation (KLHL34 sh#1: 20.1%, P=.0001 and KLHL34 sh#2: 15.8%, P=.0002), increased the cytotoxicity (KLHL34 sh#1: 14.8%, P=.019 and KLHL34 sh#2: 17.9%, P=.007) in LoVo cells, and increased radiation-induced caspase-3 activity and the sub-G1 population of cells. Conclusions: The methylation status of KLHL34 cg14232291 may be a predictive candidate of sensitivity to preoperative CRT, although further validation is needed in large cohorts using various cell types.

  9. Epigenetic Regulation of KLHL34 Predictive of Pathologic Response to Preoperative Chemoradiation Therapy in Rectal Cancer Patients

    International Nuclear Information System (INIS)

    Ha, Ye J.; Kim, Chan W.; Roh, Seon A.; Cho, Dong H.; Park, Jong L.; Kim, Seon Y.; Kim, Jong H.; Choi, Eun K.; Kim, Yong S.; Kim, Jin C.

    2015-01-01

    Purpose: Prediction of individual responsiveness to preoperative chemoradiation therapy (CRT) is urgently needed in patients with poorly responsive locally advanced rectal cancer (LARC). Methods and Materials: Candidate methylation genes associated with radiosensitivity were identified using a 3-step process. In the first step, genome-wide screening of methylation genes was performed in correlation with histopathologic tumor regression grade in 45 patients with LARC. In the second step, the methylation status of selected sites was analyzed by pyrosequencing in 67 LARC patients, including 24 patients analyzed in the first step. Finally, colorectal cancer cell clones with stable KLHL34 knockdown were generated and tested for cellular sensitivity to radiation. Results: Genome-wide screening identified 7 hypermethylated CpG sites (DZIP1 cg24107021, DZIP1 cg26886381, ZEB1 cg04430381, DKK3 cg041006961, STL cg00991794, KLHL34 cg01828474, and ARHGAP6 cg07828380) associated with preoperative CRT responses. Radiosensitivity in patients with hypermethylated KLHL34 cg14232291 was confirmed by pyrosequencing in additional cohorts. Knockdown of KLHL34 significantly reduced colony formation (KLHL34 sh#1: 20.1%, P=.0001 and KLHL34 sh#2: 15.8%, P=.0002), increased the cytotoxicity (KLHL34 sh#1: 14.8%, P=.019 and KLHL34 sh#2: 17.9%, P=.007) in LoVo cells, and increased radiation-induced caspase-3 activity and the sub-G1 population of cells. Conclusions: The methylation status of KLHL34 cg14232291 may be a predictive candidate of sensitivity to preoperative CRT, although further validation is needed in large cohorts using various cell types

  10. The Henri Mondor Procedure of Morbidity and Mortality Review Meetings: Prospective Registration of Clinical, Dosimetric, and Individual Radiosensitivity Data of Patients With Severe Radiation Toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Belkacemi, Yazid, E-mail: yazid.belkacemi@aphp.fr [AP-HP, Department of Radiation Oncology, University of Paris-Est, Créteil (France); AP-HP, Henri Mondor Breast Center, University of Paris-Est, Créteil (France); INSERM U955 Eq 07, University of Paris-Est, Créteil (France); Colson-Durand, Laurianne [AP-HP, Department of Radiation Oncology, University of Paris-Est, Créteil (France); AP-HP, Henri Mondor Breast Center, University of Paris-Est, Créteil (France); Granzotto, Adeline [INSERM, UMR1052, Radiobiology Group, Cancer Research Centre of Lyon, Lyon (France); Husheng, Shan; To, Nhu Hanh; Majdoul, Soufya; Guet, Saada; Hervé, Marie-Laure; Fonteneau, Gloria; Diana, Christian; Le Bret, Cindy; Dominique, Claude [AP-HP, Department of Radiation Oncology, University of Paris-Est, Créteil (France); Fayolle, Maryse [AP-HP, Department of Radiation Oncology, University of Paris-Est, Créteil (France); AP-HP, Henri Mondor Breast Center, University of Paris-Est, Créteil (France); Foray, Nicolas [INSERM, UMR1052, Radiobiology Group, Cancer Research Centre of Lyon, Lyon (France)

    2016-11-01

    Purpose: After radiation therapy (RT), various radiation-induced toxicities can develop in about one-fourth of patients. An international interest in using morbidity and mortality rates to monitor the quality of care and integrate morbidity and mortality review (MMR) meetings into organizations' governance processes has arisen. We report the first results of patients included in our MMR procedure that included biological assays for individual intrinsic radiosensitivity (IIRS). Methods and Materials: Twenty-three patients were prospectively included in the MMR database. Twenty-two were evaluable for IIRS. Prostate (n=10) and breast (n=8) cancers were the most frequent disease types. The total dose delivered, determined according to the type of disease, ranged from 30 to 74 Gy. Our MMR procedure requires strict criteria: patients with unresolved toxicity of grade 3 or higher with availability of clinical (photographic) data, IIRS results obtained from skin biopsy assays, treatment modalities, and follow-up data. The RT technique and dosimetry were reviewed. Results: Our prospective registration of toxicities showed mainly rectitis, occurring in 7 cases, and skin toxicities, occurring in 9. Of the 7 patients with rectitis, 5 received 66 Gy of post-prostatectomy RT with V50 (rectum volume receiving 50 Gy) ranging from 45% to 75% and a mean maximal dose of 66.5 Gy. For dermatitis and cystitis, the mean maximal doses were in the range of classical constraints without any overdosage or dose heterogeneity. No errors were found in the review of treatment planning and positioning. Conversely, all the patients were considered biologically as radiosensitive with genomic instability and ATM (ataxia telangiectasia mutated)-dependent DNA double-strand break repair impairments. Conclusions: The MMR review of files allowed clear answers for patients on the relationship between clinical events and their IIRS. Our procedure has allowed education of all our staff to monitor

  11. The Henri Mondor Procedure of Morbidity and Mortality Review Meetings: Prospective Registration of Clinical, Dosimetric, and Individual Radiosensitivity Data of Patients With Severe Radiation Toxicity

    International Nuclear Information System (INIS)

    Belkacemi, Yazid; Colson-Durand, Laurianne; Granzotto, Adeline; Husheng, Shan; To, Nhu Hanh; Majdoul, Soufya; Guet, Saada; Hervé, Marie-Laure; Fonteneau, Gloria; Diana, Christian; Le Bret, Cindy; Dominique, Claude; Fayolle, Maryse; Foray, Nicolas

    2016-01-01

    Purpose: After radiation therapy (RT), various radiation-induced toxicities can develop in about one-fourth of patients. An international interest in using morbidity and mortality rates to monitor the quality of care and integrate morbidity and mortality review (MMR) meetings into organizations' governance processes has arisen. We report the first results of patients included in our MMR procedure that included biological assays for individual intrinsic radiosensitivity (IIRS). Methods and Materials: Twenty-three patients were prospectively included in the MMR database. Twenty-two were evaluable for IIRS. Prostate (n=10) and breast (n=8) cancers were the most frequent disease types. The total dose delivered, determined according to the type of disease, ranged from 30 to 74 Gy. Our MMR procedure requires strict criteria: patients with unresolved toxicity of grade 3 or higher with availability of clinical (photographic) data, IIRS results obtained from skin biopsy assays, treatment modalities, and follow-up data. The RT technique and dosimetry were reviewed. Results: Our prospective registration of toxicities showed mainly rectitis, occurring in 7 cases, and skin toxicities, occurring in 9. Of the 7 patients with rectitis, 5 received 66 Gy of post-prostatectomy RT with V50 (rectum volume receiving 50 Gy) ranging from 45% to 75% and a mean maximal dose of 66.5 Gy. For dermatitis and cystitis, the mean maximal doses were in the range of classical constraints without any overdosage or dose heterogeneity. No errors were found in the review of treatment planning and positioning. Conversely, all the patients were considered biologically as radiosensitive with genomic instability and ATM (ataxia telangiectasia mutated)-dependent DNA double-strand break repair impairments. Conclusions: The MMR review of files allowed clear answers for patients on the relationship between clinical events and their IIRS. Our procedure has allowed education of all our staff to monitor

  12. In vitro and in vivo study of a nanoliposomal cisplatin as a radiosensitizer

    Directory of Open Access Journals (Sweden)

    Xiaomeng Zhang

    2011-02-01

    Full Text Available Xiaomeng Zhang1*, Huanjun Yang1*, Ke Gu1, Jian Chen2, Mengjie Rui2, Guo-Liang Jiang11Departments of Radiation Oncology, Fudan University Shanghai Cancer Center; Department of Oncology, Shanghai Medical College,Fudan University,Shanghai, People’s Republic of China; 2School of Pharmacy, Shanghai Jiao Tong University, Shanghai, People’s Republic of China; *Xiaomeng Zhang and Huanjun Yang share the first authorshipObjective: To investigate the in vitro and in vivo radiosensitization effect of an institutionally designed nanoliposome encapsulated cisplatin (NLE-CDDP.Materials and methods: NLE-CDDP was developed by our institute. In vitro radiosensitization of NLE-CDDP was evaluated by colony forming assay in A549 cells. In vivo radiosensitization was studied with tumor growth delay (TGD in Lewis lung carcinoma. The radiosensitization for normal tissue was investigated by jejunal crypt survival. The radiosensitization studies were carried out with a 72 h interval between drug administration and irradiation. The mice were treated with 6 mg/kg of NLE-CDDP or CDDP followed by single doses of 2 Gy, 6 Gy, 16 Gy, and 28 Gy. Sensitization enhancement ratio (SER was calculated by D0s of cell survival curves for A549 cells, doses needed to yield TGD of 20 days in Lewis lung carcinoma, or D0s of survival curves in crypt cells in radiation alone and radiation plus drug groups.Results: Our NLE-CDDP could inhibit A549 cells in vitro with half maximal inhibitory concentration of 1.12 µg/mL, and its toxicity was 2.35 times that observed in CDDP. For in vitro studies of A549 cells, SERs of NLE-CDDP and CDDP were 1.40 and 1.14, respectively, when combined with irradiation. For in vivo studies of Lewis lung carcinoma, the strongest radiosensitization was found in the 72 h interval between NLE-CDDP and irradiation. When given 72 h prior to irradiation, NLE-CDDP yielded higher radiosensitization than CDDP (SER of 4.92 vs 3.21 and slightly increased injury in jejunal

  13. Enhancement of radiosensitivity in H1299 cancer cells by actin-associated protein cofilin

    International Nuclear Information System (INIS)

    Lee, Y.-J.; Sheu, T.-J.; Keng, Peter C.

    2005-01-01

    Cofilin is an actin-associated protein that belongs to the actin depolymerization factor/cofilin family and is important for regulation of actin dynamics. Cofilin can import actin monomers into the nucleus under certain stress conditions, however the biological effects of nuclear transport are unclear. In this study, we found that over-expression of cofilin led to increased radiation sensitivity in human non-small lung cancer H1299 cells. Cell survival as determined by colony forming assay showed that cells over-expressing cofilin were more sensitive to ionizing radiation (IR) than normal cells. To determine whether the DNA repair capacity was altered in cofilin over-expressing cells, comet assays were performed on irradiated cells. Repair of DNA damage caused by ionizing radiation was detected in cofilin over-expressing cells after 24 h of recovery. Consistent with this observation, the key components for repair of DNA double-strand breaks, including Rad51, Rad52, and Ku70/Ku80, were down-regulated in cofilin over-expressing cells after IR exposure. These findings suggest that cofilin can influence radiosensitivity by altering DNA repair capacity

  14. Apoptosis-related molecules and radiation response in human oral cancers

    International Nuclear Information System (INIS)

    Teni, Tanuja; Mallick, Sanchita; Palve, Vinayak; Yasser, Mohd; Pawar, Sagar; Kannan, Sadhana; Agarwal, Jai Prakash; Kane, Shubhada

    2013-01-01

    The ability of the tumor cells to respond to radiotherapy depends upon their intrinsic radiosensitivity, which may be partly governed by molecules of the intrinsic cell death pathway. To identify the defects in this pathway in oral cancers, transcript expression analysis of the pathway members was done using the Ribonuclease protection assay in oral cell lines and tumors. The intrinsic apoptosis pathway was found to be deregulated in oral cell lines and majority of oral tumors with altered expression of Mcl-l, bclxl, survivin, p53 and p16 mRNA. To identify factors associated with radiosensitivity, differential gene expression profiles of radiation-treated versus untreated oral cell lines of differing radiosensitivities was carried out. To assess the predictive value of above altered molecules in radiotherapy outcome in oral cancer patients, pretreated biopsies from thirty nine oral cancer patients were examined for the expression of the apoptotic markers using immunohistochemistry and their expression was correlated with the clinico pathological parameters. High expression of Mcl-1 (p = 0.05) and PCNA (p = 0.007) was seen to be associated with poor disease free survival. High expression of Bcl-xL was associated with poor response to radiotherapy treatment. PCNA (p=0.04) and Mcl-1 (p=0.05) emerged as independent prognostic markers for predicting disease free survival in oral cancers treated with primary radiotherapy. A predominant overexpression of anti-apoptotic Mcl-1L over pro-apoptotic Mcl-1S isoform was observed in the oral cancer cell lines and oral tumors. An inverse correlation was observed between Mcl-1L expression and apoptosis induction in AW8507 cell line post-radiation treatment supporting its pro-survival role. A rapid and short induction of Mcl-1L versus sustained induction of Mcl-1L was observed in the relatively more radiosensitive FBM versus AW8507 respectively. siRNA treatment in combination with IR demonstrated significant induction of apoptosis

  15. ADPRT inhibitors and hyperthermia as radiosensitizers

    International Nuclear Information System (INIS)

    Jonsson, G.G.

    1985-01-01

    Hyperthermia given in combination with gamma radiation has given considerable improvement in the therapeutic results for treatment of malignant tumors. The mechanism behind the hyperthermia effect is probably operative at the tissue level as well as at the molecular level. The metabolism of NAD + in relation to the activity of the chromosomal enzyme ADP-ribosyl transferase (ADPRT) has been studied as a possible molecular mechanism for this effect. The ADPRT activity was measured after radiosensitization with both hyperthermia and nicotinamide, which is a potent inhibitor of ADPRT. The results indicate that hyperthermia can improve the effect of radiotherapy by reducing the supply of NAD + , which is a co-substrate for ADPRT, while nicotinamide functions as a radiosensitizing agent by direct inhibition of the enzyme. The hypothesis is discussed in the thesis where inhibition of ADPRT might increase the radiosensitivity because the radiation-induced DNA damage can not be repaired with normal efficiency. The function of nicotinamide as a radiosensitizer was verified by studies on C3H mice with transplanted spontaneous mammary tumors. Because nicotinamide is not toxic, it seems quite attractive to test this vitamin as a radiosensitizing agent against human tumors. (251 refs.) (author)

  16. Resveratrol enhances radiosensitivity of human non-small cell lung cancer NCI-H838 cells accompanied by inhibition of nuclear factor-kappa B activation

    International Nuclear Information System (INIS)

    Liao, Hui-Fen; Kuo Cheng-Deng; Yang, Yuh-Cheng; Lin, Chin-Ping; Tai, Hung-Chi; Chen, Yu-Jen; Chen, Yu-Yawn

    2005-01-01

    Resveratrol, a polyphenol in red wine, possesses many pharmacological activities including cardio-protection, chemoprevention, anti-tumor effects, and nuclear factor-kappa B (NF-κB) inactivation. The present study was designed to evaluate the effects and possible mechanism of resveratrol in enhancing radiosensitivity of lung cancer cells. Human non-small cell lung cancer NCI-H838 cells were irradiated with or without resveratrol pretreatment. The surviving fraction and sensitizer enhancement ratio (SER) were estimated by using a colony formation assay and linear-quadratic model. The cell-cycle distribution was evaluated by using prospidium iodide staining and flow cytometry. An enzyme-linked immunosorbent assay (ELISA)-based assay with immobilized oligonucleotide was performed to assess the DNA binding activity of NF-κB. Resveratrol had no direct growth-inhibitory effect on NCI-H838 cells treated for 24 hours with doses up to 25 μM. Pretreatment with resveratrol significantly enhanced cell killing by radiation, with an SER up to 2.2. Radiation activated NF-κB, an effect reversed by resveratrol pretreatment. Resveratrol resulted in a decrease of cells in the G 0 /G 1 phase and an increase in the S phase. Our results demonstrate that resveratrol enhances the radiosensitivity of NCI-H838 cells accompanied by NF-κB inhibition and S-phase arrest. (author)

  17. The role of polymorphisms of genes repair pathway to the radiotoxicity in patients with cancer of the cervix

    International Nuclear Information System (INIS)

    Carvalho, Ana Terra Silva

    2012-01-01

    Background: In Brazil, cervical cancer is the second most common among women. Radiation therapy is part of its interdisciplinary management, playing an important role in their loco regional control. The major challenge of modern medicine in radiotherapy is to develop predictive methods that can determine the level of radiosensitivity of the patient and the healthy surrounding tissue in order to individualize the prescribed radiation dose, to prevent severe side effects and promoting better local tumor control. This study evaluated the acute and chronic adverse effects on the skin, lower gastrointestinal tract and urinary tract of radiotherapy in 47 cervical cancer patients. Methods and Materials: Biological material was collected and DNA from peripheral blood was extracted of ali patients studied. The fragments of TP53 and ATM were amplified to be sequenced, to verify if there are any polymorphisms witch could be responsible to the radiosensitivity of the patients. Results and Discussion: In a univariate analysis, the variable age was strongly associated with a risk of acute toxicity skin (p=O,023). Patients that received a high dose of external beam radiation and patients who have undergone brachytherapy, showed a significantly higher incidence of chronic urinary tract toxicity (p=O,031) and (p=O,019), respectively. The exchange G>A in the position 5557 of the A TM gene was significantly associated with the risk of acute lower gastrointestinal tract (p=O,008). There wasn't association between the other TP53 polymorphisms analyzed and the frequency of side effects (p>O,05). Our data revealed that patients who evolved significant association presented death (p=O,019) with the increase of chronic skin radiossensitivity. Conclusions: These observations corroborate the importance of investigating the genetic profile to predict adverse side effects in cervical cancer patients undergoing radiotherapy. These genes have an important role in DNA repair pathways and probably

  18. Use of a temperature-sensitive p53 mutant to evaluate mechanisms of 5-fluorodeoxyuridine-mediated radiosensitization

    International Nuclear Information System (INIS)

    Naida, J.D.; Davis, M.A.; Lawrence, T.S.

    1996-01-01

    Purpose/Objective: Evidence exists that fluorodeoxyuridine (FdUrd)-mediated radiosensitization occurs in HT29 human colon carcinoma cells (which are p53 mutant) when these cells progress past the G 1 /S boundary in the presence of the drug. It has been demonstrated that wild type p53 levels increase following fluoropyrimidine treatment and that G 1 arrest is associated with increased p53 levels. We hypothesized that the restoration of wild type p53 function might restore G 1 /S arrest after FdUrd treatment, and that this would prevent FdUrd-mediated radiosensitization. Similarly, we hypothesized that cells containing wild type p53 would not be radiosensitized by FdUrd. Materials and Methods: Two clones of HT29 human colon cancer cells (ts29-A and ts29-G) containing murine temperature-sensitive p53 were constructed using electroporation and Geneticin selection. Incubation of these cells at the permissive temperature of 32 deg. C produces wild type p53 function and at the non permissive temperature of 38 deg. C causes mutant p53 function. A G418 resistant control cell line was also constructed (HT29neo). Cells were incubated at either 32 deg. C or 38 deg. C for 24 hours prior to irradiation and with FdUrd (100 nM) or medium only during the last 14 hours of the temperature shift. To assess progression into S phase, single-parameter (propidium iodide (PI)) and two-parameter (PI and bromodeoxyuridine) flow cytometry were performed at the end of drug exposure. A standard clonogenic assay was used. Results: We found that when ts29-A and ts29-G cells were incubated at the non-permissive (inactive p53 conformation) temperature, they progressed into S phase following exposure to FdUrd and were radiosensitized (enhancement ratio 1.5) to a degree similar to that seen in parental HT29 cells. Cells incubated at the permissive (wild-type p53 conformation) temperature demonstrated G 1 arrest, S phase depletion, and G2 arrest. In addition, FdUrd-mediated radiosensitization was

  19. Glyoxylic compounds as radiosensitizers of hypoxic cells

    International Nuclear Information System (INIS)

    Cornago, M.P.; Lopez Zumel, M.C.; Alvarez, M.V.; Izquierdo, M.C.

    1990-01-01

    The radiosensitizing effect of five glyoxal derivatives on the survival of TC-SV40 cells has been measured, under aerobic and hypoxic conditions. A toxicity study was previously performed in order to use nontoxic concentrations. The OER for the TC-SV40 cells was 2.74. None of the glyoxylic compounds showed radiosensitizing activity under aerobic conditions while in hypoxia their radiosensitizing factors decreased in the order phenylglyoxylic acid (1.68 at 8 x 10(-3) mole dm-3) greater than phenylglyoxal (1.55 at 5 x 10(-6) mole dm-3) greater than 2-2' furil (1.48 at 5 x 10(-5) mole dm-3) greater than glyoxylic acid (1.39 at 1 x 10(-3) mole dm-3) greater than glyoxal (1.30 at 5 x 10(-5) mole dm-3). The dose-modifying factors were also determined at two equimolar concentrations 5 x 10(-5) and 5 x 10(-6) mole dm-3. A concentration effect was noticed for all the compounds although their relative radiosensitizing activity kept, independently of the concentration, the same order noted above. Glyoxals with aromatic or heterocyclic rings exert a greater radiosensitization than the others. The acidic compounds have less radiosensitizing activity than their aldehydic counterparts. Interaction of these glyoxals with NPSH cellular groups was tested and the low degree of inhibition shows that this mechanism would contribute very little, if any, to the radiosensitization effect

  20. Hypofractionated Intensity Modulated Radiation Therapy in Combined Modality Treatment for Bladder Preservation in Elderly Patients With Invasive Bladder Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Turgeon, Guy-Anne [Department of Oncology, Division of Radiation Oncology, McGill University Health Centre, Montreal, Quebec (Canada); Souhami, Luis, E-mail: luis.souhami@muhc.mcgill.ca [Department of Oncology, Division of Radiation Oncology, McGill University Health Centre, Montreal, Quebec (Canada); Cury, Fabio L.; Faria, Sergio L.; Duclos, Marie [Department of Oncology, Division of Radiation Oncology, McGill University Health Centre, Montreal, Quebec (Canada); Sturgeon, Jeremy [Department of Medical Oncology, McGill University Health Centre, Montreal, Quebec (Canada); Kassouf, Wassim [Department of Urology, McGill University Health Centre, Montreal, Quebec (Canada)

    2014-02-01

    Purpose/Objective(s): To review our experience with bladder-preserving trimodality treatment (TMT) using hypofractionated intensity modulated radiation therapy (IMRT) for the treatment of elderly patients with muscle-invasive bladder cancer. Methods and Materials: Retrospective study of elderly patients treated with TMT using hypofractionated IMRT (50 Gy in 20 fractions) with concomitant weekly radiosensitizing chemotherapy. Eligibility criteria were as follows: age ≥70 years, a proven diagnosis of muscle-invasive transitional cell bladder carcinoma, stage T2-T3N0M0 disease, and receipt of TMT with curative intent. Response rate was assessed by cystoscopic evaluation and bladder biopsy. Results: 24 patients with a median age of 79 years were eligible. A complete response was confirmed in 83% of the patients. Of the remaining patients, 1 of them underwent salvage cystectomy, and no disease was found in the bladder on histopathologic assessment. After a median follow-up time of 28 months, of the patients with a complete response, 2 patients had muscle-invasive recurrence, 1 experienced locoregional failure, and 3 experienced distant metastasis. The overall and cancer-specific survival rates at 3 years were 61% and 71%, respectively. Of the surviving patients, 75% have a disease-free and functioning bladder. All patients completed hypofractionated IMRT, and 19 patients tolerated all 4 cycles of chemotherapy. Acute grade 3 gastrointestinal or genitourinary toxicities occurred in only 4% of the patients, and acute grade 3 or 4 hematologic toxicities, liver toxicities, or both were experienced by 17% of the cohort. No patient experienced grade 4 gastrointestinal or genitourinary toxicity. Conclusions: Hypofractionated IMRT with concurrent radiosensitizing chemotherapy appears to be an effective and well-tolerated curative treatment strategy in the elderly population and should be considered for patients who are not candidates for cystectomy or who wish to avoid

  1. New perspectives for radiosensitization in pancreatic carcinoma: A review of mechanisms involved in pancreatic tumorigenesis; Mecanismes de carcinogenese des cancers du pancreas: quelles pistes pour la radiosensibilisation?

    Energy Technology Data Exchange (ETDEWEB)

    Huguet, F. [Service d' oncologie-radiotherapie, hopital Tenon, Assistance publique-Hopitaux de Paris, 4, rue de la Chine, 75020 Paris (France); Universite Pierre-et-Marie-Curie Paris 6, 4, place Jussieu, 75005 Paris (France); Centre de recherche, institut Curie, campus universitaire, 91898 Orsay cedex (France); Inserm U612, campus universitaire, 91898 Orsay cedex (France); Fernet, M.; Favaudon, V. [Centre de recherche, institut Curie, campus universitaire, 91898 Orsay cedex (France); Inserm U612, campus universitaire, 91898 Orsay cedex (France); Monnier, L.; Touboul, E. [Service d' oncologie-radiotherapie, hopital Tenon, Assistance publique-Hopitaux de Paris, 4, rue de la Chine, 75020 Paris (France); Universite Pierre-et-Marie-Curie Paris 6, 4, place Jussieu, 75005 Paris (France)

    2011-08-15

    Pancreatic carcinoma is the fifth leading cause of cancer-related mortality. The 5-year overall survival is less than 5 %. This very poor prognosis can be explained both by late diagnosis and by treatment resistance, including resistance to radiation therapy. A better understanding of the pancreatic tumorigenesis and knowledge of the most frequent mutations in pancreatic adenocarcinoma (KRAS, p16, TP53, Smad4) open new perspectives for the development of more effective treatments. This review presents the major genetic and molecular alterations in pancreatic cancer that could be targeted to improve radiosensitization. (authors)

  2. Fanconi's anemia and clinical radiosensitivity. Report on two adult patients with locally advanced solid tumors treated by radiotherapy

    International Nuclear Information System (INIS)

    Bremer, M.; Karstens, J.H.; Schindler, D.; Gross, M.; Doerk, T.; Morlot, S.

    2003-01-01

    Background: Patients with Fanconi's anemia (FA) may exhibit an increased clinical radiosensitivity of various degree, although detailed clinical data are scarce. We report on two cases to underline the possible challenges in the radiotherapy of FA patients. Case Report and Results: Two 24- and 32-year-old male patients with FA were treated by definitive radiotherapy for locally advanced squamous cell head and neck cancers. In the first patient, long-term tumor control could be achieved after delivery of 67 Gy with a - in part - hyperfractionated split-course treatment regimen and, concurrently, one course of carboplatin followed by salvage neck dissection. Acute toxicity was marked, but no severe treatment-related late effects occurred. 5 years later, additional radiotherapy was administered due to a second (squamous cell carcinoma of the anus) and third (squamous cell carcinoma of the head and neck) primary, which the patient succumbed to. By contrast, the second patient experienced fatal acute hematologic toxicity after delivery of only 8 Gy of hyperfractionated radiotherapy. While the diagnosis FA could be based on flow cytometric analysis of a lymphocyte culture in the second patient, the diagnosis in the first patient had to be confirmed by hypersensitivity to mitomycin of a fibroblast cell line due to complete somatic lymphohematopoietic mosaicism. In this patient, phenotype complementation and molecular genetic analysis revealed a pathogenic mutation in the FANCA gene. The first patient has not been considered to have FA until he presented with his second tumor. Conclusion: FA has to be considered in patients presenting at young age with squamous cell carcinoma of the head and neck or anus. The diagnosis FA is of immediate importance for guiding the optimal choice of treatment. Radiotherapy or even radiochemotherapy seems to be feasible and effective in individual cases. (orig.)

  3. Radiosensitivity and genes

    Energy Technology Data Exchange (ETDEWEB)

    Qiyue, Hu; Mingyue, Lun [Suzhou Medical Coll., JS (China)

    1995-07-01

    Reported effects of some oncogenes, tumour suppressor genes and DNA repair genes on sensitivity of cells to ionizing radiation are reviewed. The role of oncogenes in cellular response to irradiation is discussed, especially the extensively studied oncogenes such as the ras gene family. For tumour suppressor genes, mainly the p53, which is increasingly implicated as a gene affecting radiosensitivity, is reviewed. It is considered that there is a cell cycle checkpoint determinant which is postulated to be able to arrest the irradiated cells in G{sub 1} phase to allow them to repair damage before they undergo DNA synthesis. So far there are six DNA repair genes which have been cloned in mammalian cells, but only one, XRCC1, appears to be involved in repair of human X-ray damage. XRCC1 can correct high sisterchromatid exchange levels when transferred into EM{sub 9} cells, but its expression seems to have no correlation with radiosensitivity of human neck and head tumour cells. Radiosensitivity is an intricate issue which may involve many factors. A scheme of cellular reactions after exposure to irradiation is proposed to indicate a possible sequence of events initiated by ionizing radiation.

  4. Radiosensitivity and genes

    International Nuclear Information System (INIS)

    Hu Qiyue; Lun Mingyue

    1995-07-01

    Reported effects of some oncogenes, tumour suppressor genes and DNA repair genes on sensitivity of cells to ionizing radiation are reviewed. The role of oncogenes in cellular response to irradiation is discussed, especially the extensively studied oncogenes such as the ras gene family. For tumour suppressor genes, mainly the p53, which is increasingly implicated as a gene affecting radiosensitivity, is reviewed. It is considered that there is a cell cycle checkpoint determinant which is postulated to be able to arrest the irradiated cells in G 1 phase to allow them to repair damage before they undergo DNA synthesis. So far there are six DNA repair genes which have been cloned in mammalian cells, but only one, XRCC1, appears to be involved in repair of human X-ray damage. XRCC1 can correct high sisterchromatid exchange levels when transferred into EM 9 cells, but its expression seems to have no correlation with radiosensitivity of human neck and head tumour cells. Radiosensitivity is an intricate issue which may involve many factors. A scheme of cellular reactions after exposure to irradiation is proposed to indicate a possible sequence of events initiated by ionizing radiation

  5. Radiosensitive Down syndrome lymphoblastoid lines have normal ionizing-radiation-induced inhibition of DNA synthesis

    International Nuclear Information System (INIS)

    Ganges, M.B.; Robbins, J.H.; Jiang, H.; Hauser, C.; Tarone, R.E.

    1988-01-01

    The extent of X-ray-induced inhibition of DNA synthesis was determined in radiosensitive lymphoblastoid lines from 3 patients with Down syndrome and 3 patients with ataxia telangiectasia (AT). Compared to 6 normal control lines, the 3 AT lines were abnormally resistant to X-ray-induced inhibition of DNA synthesis, while the 3 Down syndrome lines had normal inhibition. These results demonstrate that radiosensitive human cells can have normal X-ray-induced inhibition of DNA synthesis and provide new evidence for the dissociation of radioresistant DNA synthesis. (author). 27 refs.; 1 fig.; 1 tab

  6. Radiosensitization of human prostate cell line LNCAP by [6]- gingerol

    International Nuclear Information System (INIS)

    Silva, Josias Paulino Leal; Bellini, Maria Helena

    2017-01-01

    Full text: Introduction: Prostate cancer is the second most prevalent malignancy and second leading cause of cancer-related deaths among men in the world. Several different diagnostic and therapeutic approaches have been developed in order to decrease the death rates. A number of experimental and clinical studies have showed antiproliferative, pro-apoptotic, anti-metastatic and anti-angiogenic effects of several phytochemicals. [6]-Gingerol (1-[4'-hydroxy-3'-methoxyphenyl]-5-hydroxy-3- decanone), the major pungent principle of ginger, has anti-oxidant, anti-inflammation and antitumor promoting activities. Aim: The purpose of this study was to evaluate the radiosensitizing activity of [6]-Gingerol in the human prostate cancer cells. Methods: The viability was assessed (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) tetrazolium (MTS) assay. The prostate human cells (LNCAP) (2,5×103 cells/well) were seeded into 96-well plates, after 24 hr they were treated with 150 and 300μg/mL of [6]-Gingerol or vehicle alone (0.1% DMSO) in serum containing media. After incubation, MTS solution was added to the plate at a final concentration of 0.5 mg/mL. The cells were incubated for 2 hr in dark at 37. The resulting MTS-products were determined by measuring the absorbance at 490 nm with ELISA reader. In the clonogenic cell survival assay, the cells were divided into two groups: A) control, B) treated with [6]-Gingerol, C) irradiated control and D) treated with [6]-Gingerol and irradiated. The cells were irradiated by 60Co source in the range from 0 to 15 Gy, using the GammaCell 220 - Irradiation Unit of Canadian-Atomic Energy Commision Ltd. (CTR-IPEN). After 10-14 days of culture in normoxia conditions, cell colonies were fixed and stained with methanol 20% and crystal violet 0.5% and counted. Multiple comparisons were assessed by One-way ANOVA followed by Bonferroni´s tests with GraphPad Prism version 6.0 software. p< 0.05 was considered statistically

  7. Radiosensitization of human prostate cell line LNCAP by [6]- gingerol

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Josias Paulino Leal; Bellini, Maria Helena [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

    2017-07-01

    Full text: Introduction: Prostate cancer is the second most prevalent malignancy and second leading cause of cancer-related deaths among men in the world. Several different diagnostic and therapeutic approaches have been developed in order to decrease the death rates. A number of experimental and clinical studies have showed antiproliferative, pro-apoptotic, anti-metastatic and anti-angiogenic effects of several phytochemicals. [6]-Gingerol (1-[4'-hydroxy-3'-methoxyphenyl]-5-hydroxy-3- decanone), the major pungent principle of ginger, has anti-oxidant, anti-inflammation and antitumor promoting activities. Aim: The purpose of this study was to evaluate the radiosensitizing activity of [6]-Gingerol in the human prostate cancer cells. Methods: The viability was assessed (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) tetrazolium (MTS) assay. The prostate human cells (LNCAP) (2,5×103 cells/well) were seeded into 96-well plates, after 24 hr they were treated with 150 and 300μg/mL of [6]-Gingerol or vehicle alone (0.1% DMSO) in serum containing media. After incubation, MTS solution was added to the plate at a final concentration of 0.5 mg/mL. The cells were incubated for 2 hr in dark at 37. The resulting MTS-products were determined by measuring the absorbance at 490 nm with ELISA reader. In the clonogenic cell survival assay, the cells were divided into two groups: A) control, B) treated with [6]-Gingerol, C) irradiated control and D) treated with [6]-Gingerol and irradiated. The cells were irradiated by 60Co source in the range from 0 to 15 Gy, using the GammaCell 220 - Irradiation Unit of Canadian-Atomic Energy Commision Ltd. (CTR-IPEN). After 10-14 days of culture in normoxia conditions, cell colonies were fixed and stained with methanol 20% and crystal violet 0.5% and counted. Multiple comparisons were assessed by One-way ANOVA followed by Bonferroni´s tests with GraphPad Prism version 6.0 software. p< 0.05 was considered statistically

  8. Correlation of in vitro lymphocyte radiosensitivity and gene expression with late normal tissue reactions following curative radiotherapy for breast cancer

    International Nuclear Information System (INIS)

    Finnon, Paul; Kabacik, Sylwia; MacKay, Alan; Raffy, Claudine; A’Hern, Roger; Owen, Roger; Badie, Christophe; Yarnold, John; Bouffler, Simon

    2012-01-01

    Background and purpose: Identification of mechanisms of late normal tissue responses to curative radiotherapy that discriminate individuals with marked or mild responses would aid response prediction. This study aimed to identify differences in gene expression, apoptosis, residual DNA double strand breaks and chromosomal damage after in vitro irradiation of lymphocytes in a series of patients with marked (31 cases) or mild (28 controls) late adverse reaction to adjuvant breast radiotherapy. Materials and methods: Gene expression arrays, residual γH2AX, apoptosis, G2 chromosomal radiosensitivity and G0 micronucleus assay were used to compare case and control lymphocyte radiation responses. Results: Five hundred and thirty genes were up-regulated and 819 down-regulated by ionising radiation. Irradiated samples were identified with an overall cross-validated error rate of 3.4%. Prediction analyses to classify cases and controls using unirradiated (0 Gy), irradiated (4 Gy) or radiation response (4–0 Gy) expression profiles correctly identified samples with, respectively, 25%, 22% or 18.5% error rates. Significant inter-sample variation was observed for all cellular endpoints but cases and controls could not be distinguished. Conclusions: Variation in lymphocyte radiosensitivity does not necessarily correlate with normal tissue response to radiotherapy. Gene expression analysis can predict of radiation exposure and may in the future help prediction of normal tissue radiosensitivity.

  9. Radiosensitizing effect of gold nanoparticles in carbon ion irradiation of human cervical cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Harminder; Avasthi, D. K.; Pujari, Geetanjali; Sarma, Asitikantha [Inter University Accelerator Centre, Aruna Asaf Ali Marg, Post box-10502, New Delhi-110067 (India)

    2013-07-18

    Noble metal nanoparticles have received considerable attention in biotechnology for their role in bio sensing due to surface plasmon resonance, medical diagnostics due to better imaging contrast and therapy. The radiosensitization effect of gold nanoparticles (AuNP) has been gaining popularity in radiation therapy of cancer cells. The better depth dose profile of energetic ion beam proves its superiority over gamma radiation for fighting against cancer. In the present work, the glucose capped gold nanoparticles (Glu-AuNP) were synthesised and internalized in the HeLa cells. Transmission electron microscopic analysis of ultrathin sections of Glu-AuNP treated HeLa cells confirmed the internalization of Glu-AuNPs. Control HeLa cells and Glu-AuNp treated HeLa cells were irradiated at different doses of 62 MeV 12C ion beam (LET - 290keV/{mu}m) at BIO beam line of using 15UD Pelletron accelerator at Inter University Accelerator Centre, New Delhi, India. The survival fraction was assessed by colony forming assay which revealed that the dose of carbon ion for 90% cell killing in Glu-AuNP treated HeLa cells and control HeLa cells are 2.3 and 3.2 Gy respectively. This observation shows {approx} 28% reduction of {sup 12}C{sup 6+} ion dose for Glu-AuNP treated HeLa cells as compared to control HeLa cells.

  10. Radiosensitizing effect of gold nanoparticles in carbon ion irradiation of human cervical cancer cells

    International Nuclear Information System (INIS)

    Kaur, Harminder; Avasthi, D. K.; Pujari, Geetanjali; Sarma, Asitikantha

    2013-01-01

    Noble metal nanoparticles have received considerable attention in biotechnology for their role in bio sensing due to surface plasmon resonance, medical diagnostics due to better imaging contrast and therapy. The radiosensitization effect of gold nanoparticles (AuNP) has been gaining popularity in radiation therapy of cancer cells. The better depth dose profile of energetic ion beam proves its superiority over gamma radiation for fighting against cancer. In the present work, the glucose capped gold nanoparticles (Glu-AuNP) were synthesised and internalized in the HeLa cells. Transmission electron microscopic analysis of ultrathin sections of Glu-AuNP treated HeLa cells confirmed the internalization of Glu-AuNPs. Control HeLa cells and Glu-AuNp treated HeLa cells were irradiated at different doses of 62 MeV 12C ion beam (LET – 290keV/μm) at BIO beam line of using 15UD Pelletron accelerator at Inter University Accelerator Centre, New Delhi, India. The survival fraction was assessed by colony forming assay which revealed that the dose of carbon ion for 90% cell killing in Glu-AuNP treated HeLa cells and control HeLa cells are 2.3 and 3.2 Gy respectively. This observation shows ∼ 28% reduction of 12 C 6+ ion dose for Glu-AuNP treated HeLa cells as compared to control HeLa cells

  11. Effect of DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine on radiosensitivity of the human lung cancer cells in three-dimensional culture

    International Nuclear Information System (INIS)

    Pan Dong; Xue Gang; Li Xiaoman; Chen Yaxiong; Ren Zhenxin; Du Yarong; Hu Burong

    2014-01-01

    5-Aza-CdR is a specific inhibitor of DNMTs which could suppress tumor growth by demethylation of genomic DNA. There have only few studies thus far concerning it as radiosensitizers in three-dimensional (3D) cells. The principal aim of this study is to evaluate the effects of 5-Aza-CdR on the radiosensitivity of A549 cells in monolayer (2D) and 3D cultures in an attempt to find out a new combination treatments with radiotherapy. The cell proliferation was detected by MTT assay after pretreated with different doses of 5-Aza-CdR for 72 h. A549 cells were treated with or without 5-Aza-CdR (2, 5 μmol/L) for 72 h before be exposed to X-rays of 1, 2, 4, 6 Gy, respectively. The DNA damage was evaluated by micronucleus assay and clonogenic assays. Pretreatment with 5-Aza-CdR inhibited the A549 cell proliferation significantly. More micronucleus were observed after irradiation in 3D cells pretreated with 2 and 5 μmol/L concentration of drug than those without treatment. The survival fractions of cells pretreated by both 2 and 5 μmol/L drug reduced significantly in 3D cultures after irradiation. These significances, however, were found in 2D cells pretreated by only 5 μmol/L drug. Our results suggest that 5-Aza-CdR can inhibit the A549 cells proliferation and apparently enhance the radiosensitivity of cells in 3D cultures. Using of the low dose 5-Aza-CdR in clinical radiotherapy may reduce side effects and enhance effectively the cancer target therapy. (authors)

  12. Hepatocytes Determine the Hypoxic Microenvironment and Radiosensitivity of Colorectal Cancer Cells Through Production of Nitric Oxide That Targets Mitochondrial Respiration

    International Nuclear Information System (INIS)

    Jiang, Heng; Verovski, Valeri N.; Leonard, Wim; Law, Ka Lun; Vermeersch, Marieke; Storme, Guy; Van den Berge, Dirk; Gevaert, Thierry; Sermeus, Alexandra; De Ridder, Mark

    2013-01-01

    Purpose: To determine whether host hepatocytes may reverse hypoxic radioresistance through nitric oxide (NO)-induced oxygen sparing, in a model relevant to colorectal cancer (CRC) liver metastases. Methods and Materials: Hepatocytes and a panel of CRC cells were incubated in a tissue-mimetic coculture system with diffusion-limited oxygenation, and oxygen levels were monitored by an oxygen-sensing fluorescence probe. To activate endogenous NO production, cocultures were exposed to a cytokine mixture, and the expression of inducible nitric oxide synthase was analyzed by reverse transcription–polymerase chain reaction, Western blotting, and NO/nitrite production. The mitochondrial targets of NO were examined by enzymatic activity. To assess hypoxic radioresponse, cocultures were irradiated and reseeded for colonies. Results: Resting hepatocytes consumed 10-40 times more oxygen than mouse CT26 and human DLD-1, HT29, HCT116, and SW480 CRC cells, and thus seemed to be the major effectors of hypoxic conditioning. As a result, hepatocytes caused uniform radioprotection of tumor cells at a 1:1 ratio. Conversely, NO-producing hepatocytes radiosensitized all CRC cell lines more than 1.5-fold, similar to the effect of selective mitochondrial inhibitors. The radiosensitizing effect was associated with a respiratory self-arrest of hepatocytes at the level of aconitase and complex II, which resulted in profound reoxygenation of tumor cells through oxygen sparing. Nitric oxide–producing hepatocytes were at least 10 times more active than NO-producing macrophages to reverse hypoxia-induced radioresistance. Conclusions: Hepatocytes were the major determinants of the hypoxic microenvironment and radioresponse of CRC cells in our model of metabolic hypoxia. We provide evidence that reoxygenation and radiosensitization of hypoxic CRC cells can be achieved through oxygen sparing induced by endogenous NO production in host hepatocytes

  13. Hepatocytes Determine the Hypoxic Microenvironment and Radiosensitivity of Colorectal Cancer Cells Through Production of Nitric Oxide That Targets Mitochondrial Respiration

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Heng; Verovski, Valeri N.; Leonard, Wim; Law, Ka Lun; Vermeersch, Marieke; Storme, Guy; Van den Berge, Dirk; Gevaert, Thierry; Sermeus, Alexandra [Department of Radiotherapy, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels (Belgium); De Ridder, Mark, E-mail: mark.deridder@uzbrussel.be [Department of Radiotherapy, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels (Belgium)

    2013-03-01

    Purpose: To determine whether host hepatocytes may reverse hypoxic radioresistance through nitric oxide (NO)-induced oxygen sparing, in a model relevant to colorectal cancer (CRC) liver metastases. Methods and Materials: Hepatocytes and a panel of CRC cells were incubated in a tissue-mimetic coculture system with diffusion-limited oxygenation, and oxygen levels were monitored by an oxygen-sensing fluorescence probe. To activate endogenous NO production, cocultures were exposed to a cytokine mixture, and the expression of inducible nitric oxide synthase was analyzed by reverse transcription–polymerase chain reaction, Western blotting, and NO/nitrite production. The mitochondrial targets of NO were examined by enzymatic activity. To assess hypoxic radioresponse, cocultures were irradiated and reseeded for colonies. Results: Resting hepatocytes consumed 10-40 times more oxygen than mouse CT26 and human DLD-1, HT29, HCT116, and SW480 CRC cells, and thus seemed to be the major effectors of hypoxic conditioning. As a result, hepatocytes caused uniform radioprotection of tumor cells at a 1:1 ratio. Conversely, NO-producing hepatocytes radiosensitized all CRC cell lines more than 1.5-fold, similar to the effect of selective mitochondrial inhibitors. The radiosensitizing effect was associated with a respiratory self-arrest of hepatocytes at the level of aconitase and complex II, which resulted in profound reoxygenation of tumor cells through oxygen sparing. Nitric oxide–producing hepatocytes were at least 10 times more active than NO-producing macrophages to reverse hypoxia-induced radioresistance. Conclusions: Hepatocytes were the major determinants of the hypoxic microenvironment and radioresponse of CRC cells in our model of metabolic hypoxia. We provide evidence that reoxygenation and radiosensitization of hypoxic CRC cells can be achieved through oxygen sparing induced by endogenous NO production in host hepatocytes.

  14. Laryngeal preservation with definitive radiotherapy in radiosensitive hypopharyngeal cancer

    International Nuclear Information System (INIS)

    Kunitake, Naonobu; Nakamura, Katsumasa; Shioyama, Yoshiyuki; Kuratomi, Yuichiro; Yamamoto, Tomoya; Honda, Hiroshi; Terashima, Hiromi

    2003-01-01

    Fifty-seven patients with hypopharyngeal cancer treated by irradiation at Kyushu University Hospital between 1985 and 1992 were analyzed retrospectively. They included 53 men and 4 women, and their ages ranged from 39 to 83 years (mean, 63 years). Two patients had stage I, 7 had stage II, 13 had stage III, and 35 had stage IV disease according to the Union Internationale Contre le Cancer (UICC) (1997) classification. Initially, they were irradiated in the conventional way with a dose of 30 Gy, and 17 patients with good response were irradiated to curative dose (more than 60 Gy), and 32 patients with poor response were operated immediately. Medically inoperable or unresectable patients were treated in a semiradical way (n=8). The 5-year overall and cause-specific survival rates were 46% and 51%, respectively. Five-year cause-specific survival rates were 88% for stages I and II (n=9), 67% for stage III (n=13), and 35% for stage IV (n=35). Five-year cause-specific survival according to treatment method was 58% for surgery and 51 % for curative radiotherapy. There was no statistically significant difference between the two rates. These results suggest that initial radiation response is an important factor in deciding on the following treatment method. Curative radiotherapy for hypopharyngeal cancer according to initial radiation response is a desirable treatment strategy. (author)

  15. TCP isoeffect analysis using a heterogeneous distribution of radiosensitivity

    International Nuclear Information System (INIS)

    Carlone, Marco; Wilkins, David; Nyiri, Balazs; Raaphorst, Peter

    2004-01-01

    A formula for the α/β ratio is derived using the heterogeneous (population averaged) tumor control model. This formula is nearly identical to the formula obtained using the homogeneous (individual) tumor control model, but the new formula includes extra terms showing that the α/β ratio, the ratio of the mean value of α divided by the mean value of β that would be observed in a patient population, explicitly depends on the survival level and heterogeneity. The magnitude of this correction is estimated for prostate cancer, and this appears to raise the mean value of the ratio estimate by about 20%. The method also allows investigation of confidence limits for α/β based on a population distribution of radiosensitivity. For a widely heterogeneous population, the upper 95% confidence interval for the α/β ratio can be as high as 7.3 Gy, even though the population mean is between 2.3 and 2.6 Gy

  16. SN-38 Acts as a Radiosensitizer for Colorectal Cancer by Inhibiting the Radiation-induced Up-regulation of HIF-1α.

    Science.gov (United States)

    Okuno, Takayuki; Kawai, Kazushige; Hata, Keisuke; Murono, Koji; Emoto, Shigenobu; Kaneko, Manabu; Sasaki, Kazuhito; Nishikawa, Takeshi; Tanaka, Toshiaki; Nozawa, Hiroaki

    2018-06-01

    Hypoxia offers resistance to therapy in human solid tumors. The aim of the study was to investigate whether SN-38, the active metabolite of irinotecan, acts as a radiosensitizer through inhibition of hypoxia-inducible factor (HIF)-1α in the human colorectal cancer (CRC) cells. HT29 and SW480 cells were cultured with SN-38 (0-4 μM) immediately after irradiation (0-8 Gy). HIF-1α expression was assessed using flow-cytometry and western blot analysis. Cell proliferation was evaluated by the calcein assay. Apoptosis and cell cycle were determined by flow-cytometry. Radiation up-regulated HIF-1α, and SN-38 inhibited the radiation-induced HIF-1α. The combination of radiation and SN-38 inhibited cell proliferation more than radiation alone; treatment with SN-38 after radiation exposure did not increase the number of apoptotic cells, whereas, it enhanced the S and G 2 /M cell-cycle arrest and decreased the population of cells in G 1 Conclusion: SN-38 inhibits the radiation-induced up-regulation of HIF-1α and acts as a radiosensitizer by inducing cell-cycle arrest in CRC cells. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  17. Silencing of osteopontin promotes the radiosensitivity of breast cancer cells by reducing the expression of hypoxia inducible factor 1 and vascular endothelial growth factor

    Institute of Scientific and Technical Information of China (English)

    YANG Li; ZHAO Wei; ZUO Wen-shu; WEI Ling; SONG Xian-rang; WANG Xing-wu; ZHENG Gang; ZHENG Mei-zhu

    2012-01-01

    Background Osteopontin (OPN) is a secreted phosphoglycoprotein (SSP) that is overexpressed in a variety of tumors and was regarded as a molecular marker of tumors.In this study,we intended to demonstrate the role of OPN in human breast cancer cell line MDA-MB-231.Methods Recombinant plasmid expressing small interfering RNA (siRNA) specific to OPN mRNA was transfected into MDA-MB-231 cells to generate the stable transfected cell line MDA-MB-343,and the empty plasmid tansfected cells (MDA-MB-neg) or wildtype MDA-MB-231 cells were used as control cells respectively.Expression of OPN,hypoxia inducible factor-1 (HIF-1) and vascular endothelial growth factor (VEGF) proteins was analyzed by Western blotting analysis.The radiosensitivity of cells was determined by detecting cell apoptosis,cell proliferation and cell senescence.Results HIF-1 and VEGF proteins in MDA-MB-343 cells were significantly downregulated upon the efficient knockdown of OPN expression under either hypoxia or normoxia environment.Moreover,expression of OPN protein was upregualted upon hypoxic culture.Stable OPN-silencing also decreased cell invasion,increased cell apoptosis and cell senescence,as well as reduced clonogenic survival,resulting in increase radiation tolerance.Conclusions Suppression of OPN gene expression can enhance radiosensitivity and affect cell apoptosis in breast cancer cells.OPN seems to be an attractive target for the improvement of radiotherapy.

  18. Hormonal status can modify radiosensitivity

    International Nuclear Information System (INIS)

    Ricoul, M.; Sabatier, L.; Dutrillaux, B.

    1997-01-01

    In preliminary experiments, we have demonstrated that pregnancy increases chromosome radiosensitivity in the mouse at the end of gestation. Blood obtained from women at various times of pregnancy was then exposed to ionizing radiations in vitro. By comparison to non pregnant women, an increase in chromosome breakages was observed in metaphases from lymphocytes. Immediately after delivery, this increase of radiosensitivity disappeared. In a prospective study, serial analyses showed a very strong correlation between the amount of pregnancy hormones, progesterone in particular, and the increase of radiosensitivity. Thus, pregnant women may have an increased sensitivity to ionizing radiation during the second half of their pregnancy and the risks of radiation exposure of pregnant women have to be considered not only n relation to the child, but also to their own hypersensitivity. (authors)

  19. Impact of various parameters in detecting chromosomal aberrations by FISH to describe radiosensitivity

    International Nuclear Information System (INIS)

    Keller, U.; Mueller, E.; Grabenbauer, G.; Sauer, R.; Distel, L.; Kuechler, A.; Liehr, T.

    2004-01-01

    Background and purpose: analysis of radiation-induced chromosomal aberrations is regarded as the ''gold standard'' for classifying individual radiosensitivity. A variety of different parameters can be used. The crucial question, however, is to explore which parameter is suited best to describe the differences between patients with increased radiosensitivity and healthy individuals. Patients and methods: in this study, five patients with severe radiation-induced late effects of at least grade 3, classified according to the Radiation Therapy Oncology Group (RTOG), and eleven healthy individuals were examined retrospectively. Peripheral blood lymphocytes were irradiated in vitro with 0.7 Gy and 2.0 Gy prior to cultivation and stained by means of three-color fluorescence in situ hybridization (FISH). The detailed analysis was focused on the number of breaks per metaphase, on breaks from complex chromosomal rearrangements per metaphase, as well as on the percentage of translocations, dicentric chromosomes, breaks, and excess acentric fragments - each in comparison with the total number of mitoses analyzed. Results: using the number of breaks from complex chromosomal rearrangements after 2.0 Gy, radiosensitive patients as endpoint were clearly to be distinguished (p = 0.001) from healthy individuals. Translocations (p = 0.001) as well as breaks per metaphase (p = 0.002) were also suitable indicators for detecting differences between patients and healthy individuals. The parameters ''percentage of dicentric chromosomes'', ''breaks'', and ''excess acentric fragments'' in comparison to the total number of mitoses analyzed could neither serve as meaningful nor as significant criteria, since they showed a strong interindividual variability. Conclusion: to detect a difference in chromosomal aberrations between healthy and radiosensitive individuals, the parameters ''frequency of breaks per metaphase'', ''complex chromosomal rearrangements'', and ''translocations'' are most

  20. Studies on Drosophila radiosensitive strains

    International Nuclear Information System (INIS)

    Varentsova, E.P.; Zakharov, I.A.

    1976-01-01

    45 of radiosensitive strains of Drosophila melanogaster were isolated by Curly/Lobe technique after EMS treatment of Livadia population males. The lethality of non-Curly late larvae after gamma-irradiation (4000r) characterized radiosensitivity strains. Most of them exhibited higher frequency of the spontaneous dominant lethals (up to 69%). The males of 6 strains were semi-sterile. 5 of these strains exhibited higher frequency of X-chromosome non-disjunction

  1. Whole brain radiotherapy with radiosensitizer for brain metastases

    Directory of Open Access Journals (Sweden)

    Viani Gustavo

    2009-01-01

    Full Text Available Abstract Purpose To study the efficacy of whole brain radiotherapy (WBRT with radiosensitizer in comparison with WBRT alone for patients with brain metastases in terms of overall survival, disease progression, response to treatment and adverse effects of treatment. Methods A meta-analysis of randomized controlled trials (RCT was performed in order to compare WBRT with radiosensitizer for brain metastases and WBRT alone. The MEDLINE, EMBASE, LILACS, and Cochrane Library databases, in addition to Trial registers, bibliographic databases, and recent issues of relevant journals were researched. Significant reports were reviewed by two reviewers independently. Results A total of 8 RCTs, yielding 2317 patients were analyzed. Pooled results from this 8 RCTs of WBRT with radiosensitizer have not shown a meaningful improvement on overall survival compared to WBRT alone OR = 1.03 (95% CI0.84–1.25, p = 0.77. Also, there was no difference in local brain tumor response OR = 0.8(95% CI 0.5 – 1.03 and brain tumor progression (OR = 1.11, 95% CI 0.9 – 1.3 when the two arms were compared. Conclusion Our data show that WBRT with the following radiosentizers (ionidamine, metronidazole, misonodazole, motexafin gadolinium, BUdr, efaproxiral, thalidomide, have not improved significatively the overall survival, local control and tumor response compared to WBRT alone for brain metastases. However, 2 of them, motexafin- gadolinium and efaproxiral have been shown in recent publications (lung and breast to have positive action in lung and breast carcinoma brain metastases in association with WBRT.

  2. Rigosertib Is a More Effective Radiosensitizer Than Cisplatin in Concurrent Chemoradiation Treatment of Cervical Carcinoma, In Vitro and In Vivo

    International Nuclear Information System (INIS)

    Agoni, Lorenzo; Basu, Indranil; Gupta, Seema; Alfieri, Alan; Gambino, Angela; Goldberg, Gary L.; Reddy, E. Premkumar; Guha, Chandan

    2014-01-01

    Purpose: To compare rigosertib versus cisplatin as an effective radiosensitizing agent for cervical malignancies. Methods and Materials: Rigosertib and cisplatin were tested in cervical cancer cell lines, HeLa and C33A. A 24-hour incubation with rigosertib and cisplatin, before irradiation (2-8 Gy), was used for clonogenic survival assays. Cell cycle analysis (propidium iodide staining) and DNA damage (γ-H2AX expression) were evaluated by fluorescence-activated cell sorter cytometry. Rigosertib was also tested in vivo in tumor growth experiments on cervical cancer xenografts. Results: Rigosertib was demonstrated to induce a G 2 /M block in cancer cells. Survival curve comparison revealed a dose modification factor, as index of radiosensitization effect, of 1.1-1.3 for cisplatin and 1.4-2.2 for rigosertib. With 6-Gy irradiation, an increase in DNA damage of 15%-25% was achieved in both HeLa and C33A cells with cisplatin pretreatment, and a 71-108% increase with rigosertib pretreatment. In vivo tumor growth studies demonstrated higher performance of rigosertib when compared with cisplatin, with 53% longer tumor growth delay. Conclusions: Rigosertib was more effective than cisplatin when combined with radiation and caused minimal toxicity. These data support the need for clinical trials with rigosertib in combination therapy for patients with cervical carcinoma

  3. Effect of radiotherapy on the natural killer (NK)-cell activity of cancer patients

    International Nuclear Information System (INIS)

    McGinnes, K.; Florence, J.; Penny, R.

    1987-01-01

    The aim of this study was to determine the effect of radiotherapy on peripheral blood natural killer (NK)-cell number and activity in 15 patients with cancer, prior to the commencement and at the completion of radiotherapy. The following observations were made. Prior to radiotherapy NK activity could not be correlated with the stage of malignancy. In all patients with advanced disease and with subnormal baseline NK activity, the outcome of radiotherapy was unfavorable. Following radiotherapy to sites including the mediastinum, patients had decreased NK activity compared with those receiving treatment to other sites. This decrease was not related to the dose of radiotherapy or stage of malignancy. The tumor response was favorable in most patients whose NK activity decreased as a result of radiotherapy. The decrease in NK activity may be associated with a decrease in the percentage of NK (N901) cells in the peripheral blood. The reduction in NK activity in those patients receiving mediastinal irradiation may be due to the large volume of blood which transits the field, so that the NK cells, or their more radiosensitive precursors, may be damaged and/or differentiation inhibited. Thus, these new observations show that radiotherapy does indeed affect the NK activity in cancer patients predominantly when the irradiation site includes the mediastinum

  4. Poor Prognosis Associated With Human Papillomavirus α7 Genotypes in Cervical Carcinoma Cannot Be Explained by Intrinsic Radiosensitivity

    International Nuclear Information System (INIS)

    Hall, John S.; Iype, Rohan; Armenoult, Lucile S.C.; Taylor, Janet; Miller, Crispin J.; Davidson, Susan; Sanjose, Silvia de; Bosch, Xavier; Stern, Peter L.; West, Catharine M.L.

    2013-01-01

    Purpose: To investigate the relationship between human papillomavirus (HPV) genotype and outcome after radiation therapy and intrinsic radiosensitivity. Methods and Materials: HPV genotyping was performed on cervix biopsies by polymerase chain reaction using SPF-10 broad-spectrum primers, followed by deoxyribonucleic acid enzyme immunoassay and genotyping by reverse hybridization line probe assay (LiPA 25 ) (version 1) (n=202). PapilloCheck and quantitative reverse transcription-polymerase chain reaction were used to genotype cervix cancer cell lines (n=16). Local progression-free survival after radiation therapy alone was assessed using log-rank and Cox proportionate hazard analyses. Intrinsic radiosensitivity was measured as surviving fraction at 2 Gy (SF2) using clonogenic assays. Results: Of the 202 tumors, 107 (53.0%) were positive for HPV16, 29 (14.4%) for HPV18, 9 (4.5%) for HPV45, 23 (11.4%) for other HPV genotypes, and 22 (10.9%) were negative; 11 (5.5%) contained multiple genotypes, and 1 tumor was HPV X (0.5%). In 148 patients with outcome data, those with HPVα9-positive tumors had better local progression-free survival compared with α7 patients in univariate (P<.004) and multivariate (hazard ratio 1.54, 95% confidence interval 1.11-1.76, P=.021) analyses. There was no difference in the median SF2 of α9 and α7 cervical tumors (n=63). In the cell lines, 9 were α7 and 4 α9 positive and 3 negative. There was no difference in SF2 between α9 and α7 cell lines (n=14). Conclusion: The reduced radioresponsiveness of α7 cervical tumors is not related to intrinsic radiosensitivity

  5. Poor Prognosis Associated With Human Papillomavirus α7 Genotypes in Cervical Carcinoma Cannot Be Explained by Intrinsic Radiosensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Hall, John S.; Iype, Rohan; Armenoult, Lucile S.C. [Translational Radiobiology Group, Institute of Cancer Sciences, Manchester Academic Health Science Centre, University of Manchester, Manchester (United Kingdom); Taylor, Janet [Translational Radiobiology Group, Institute of Cancer Sciences, Manchester Academic Health Science Centre, University of Manchester, Manchester (United Kingdom); Applied Computational Biology and Bioinformatics Group, Paterson Institute for Cancer Research, Manchester (United Kingdom); Miller, Crispin J. [Applied Computational Biology and Bioinformatics Group, Paterson Institute for Cancer Research, Manchester (United Kingdom); Davidson, Susan [Christie National Health Service Foundation Trust, Manchester (United Kingdom); Sanjose, Silvia de; Bosch, Xavier [Cancer Epidemiology Research Program, Catalan Institute of Oncology, L' Hospitalet de Llobregat (Spain); Stern, Peter L. [Immunology Group, Paterson Institute for Cancer Research, Manchester (United Kingdom); West, Catharine M.L., E-mail: Catharine.West@manchester.ac.uk [Translational Radiobiology Group, Institute of Cancer Sciences, Manchester Academic Health Science Centre, University of Manchester, Manchester (United Kingdom)

    2013-04-01

    Purpose: To investigate the relationship between human papillomavirus (HPV) genotype and outcome after radiation therapy and intrinsic radiosensitivity. Methods and Materials: HPV genotyping was performed on cervix biopsies by polymerase chain reaction using SPF-10 broad-spectrum primers, followed by deoxyribonucleic acid enzyme immunoassay and genotyping by reverse hybridization line probe assay (LiPA{sub 25}) (version 1) (n=202). PapilloCheck and quantitative reverse transcription-polymerase chain reaction were used to genotype cervix cancer cell lines (n=16). Local progression-free survival after radiation therapy alone was assessed using log-rank and Cox proportionate hazard analyses. Intrinsic radiosensitivity was measured as surviving fraction at 2 Gy (SF2) using clonogenic assays. Results: Of the 202 tumors, 107 (53.0%) were positive for HPV16, 29 (14.4%) for HPV18, 9 (4.5%) for HPV45, 23 (11.4%) for other HPV genotypes, and 22 (10.9%) were negative; 11 (5.5%) contained multiple genotypes, and 1 tumor was HPV X (0.5%). In 148 patients with outcome data, those with HPVα9-positive tumors had better local progression-free survival compared with α7 patients in univariate (P<.004) and multivariate (hazard ratio 1.54, 95% confidence interval 1.11-1.76, P=.021) analyses. There was no difference in the median SF2 of α9 and α7 cervical tumors (n=63). In the cell lines, 9 were α7 and 4 α9 positive and 3 negative. There was no difference in SF2 between α9 and α7 cell lines (n=14). Conclusion: The reduced radioresponsiveness of α7 cervical tumors is not related to intrinsic radiosensitivity.

  6. Radiosensitiviness of blood lymphocytes from skin cancer patients and healthy volunteers as determined by micronucleus assay

    International Nuclear Information System (INIS)

    Lohmann, Tania Helena Ochi.

    1995-01-01

    Cancer, a major death cause in developed countries, has been related to somatic mutations that could be detected by cytogenetic analysis. Among the tools used in these tests, the micronucleus assay has been largely applied at population surveillance, biological dosimetry and early detection of groups with higher risks to developing cancers. In this study, we analysed the chromosome susceptibility of blood lymphocytes from basocellular skin cancer patients and healthy volunteers. The cytogenetic analysis was performed by a micronucleus assay, using progressive doses of ionizing radiation from a 60 Co source as mutagen. Briefly, the blood lymphocytes were irradiated in vitro, as processed by the cytokinesis-blocked method. The micronucleus frequency and distribution, cell cycle kinetics, nucleation index and dose-response relationship were determined in each patient. The results showed that the basocellular skin cancer patients lymphocytes presented higher spontaneous micronucleus frequency as compared with those from healthy young volunteers but lower than healthy now young volunteers . The radiation-induced micronucleus analysis showed that the basocellular skin cancer patients' lymphocytes presented similar proportion of damage lymphocytes as compared with those from healthy volunteers. Nevertheless, the magnitude of this damage was higher in this group with doses. Higher than 400 c Gy, which was not occurred in healthy volunteers. Cell cycle kinetics, as determined by the nucleation index, was lower in basocellular skin cancer patients as compared with healthy volunteers, indicating a more slow cell cycle. Our data showed that the lymphocytes from carcinoma basocellular patients were more radiosensitive as compared with those form healthy volunteers. (author). 159 refs., 21 figs., 16 tabs

  7. Apoptosis and radiosensitivity induced by N-acety1 phytosphingosine, in human cancer cell line

    International Nuclear Information System (INIS)

    Kim, Y. H.; Kim, K. S.; Han, Y. S.; Jeon, S. J.; Song, J. Y.; Jung, I. S.; Hong, S. H.; Yun, Y. S.; Park, J. S.

    2004-01-01

    Ceramide is a key lipid molecule in signal transduction with a role in various regulatory pathways including differentiation, proliferation and especially apoptosis. Ionizing radiation-induced apoptosis is associated with accumulation of ceramide, and the sphingomyelinase deficiency results in radioresistance. We investigated the exogenous treatment of N-acetyl-phytosphingosine (NAPS), an analogue of N-acetyl-sphingosine (C 2 -Ceramide), and C 2 -ceramide exert apoptotic effect on human T cell lymphoma Jurkat cells and breast cancer cell line MDA-MB-231. NAPS and C 2 -Ceramide has cytotoxic effect in time- and dose-dependent manner, and increased caspase-3, 8 activity. However, NAPS induced apoptosis more effectively, and increased caspase activity induced by NAPS is more higher than C 2 -ceramide. Moreover, NAPS decreased clonogenicity of irradiated cells and increased radiation-induced apoptosis significantly. Increased cell death by irradiation in the presence of NAPS is owing to the increase of caspase activity. These data suggest that NAPS might be used for lead as a new type of radiosensitizing agent increasing radiation-induced apoptosis

  8. Bax/Bcl-2 expression ratio in prediction of response to breast cancer radiotherapy

    Directory of Open Access Journals (Sweden)

    Hosein Azimian

    2018-03-01

    Full Text Available Objective(s: Radiotherapy is one of the most effective modalities of cancer therapy, but clinical responses of individual patients varies considerably. To enhance treatment efficiency it is essential to implement an individual-based treatment. The aim of present study was to identify the mechanism of intrinsic apoptosis pathway on radiosensitivity and normal tissue complications caused by the radiotherapy. Materials and Methods: Peripheral blood mononuclear cells from ten breast cancer patients were exposed to 6MV X-rays to deliver 1 and 2 Gy. Expression levels of Bax, Bcl-2, and Bax/Bcl-2 ratio were examined by relative quantitative RT-PCR. All the patients received similar tangential irradiation of the whole breast and conventional fractionation. Skin dosimetry was done by GAFChromic EBT-3 film and clinical radiosensitivity was determined using the acute reactions to radiotherapy of the skin according to Radiation Therapy Oncology Group score. All statistical analyses were performed using GraphPad Prism, version 7.01. Results: In the in-vitro experiment, Bax and Bax/Bcl-2 ratios were significantly increased with 1 and 2 Gy doses (PP0.05 for all patients. Conclusion: Significant correlation between Bax/Bcl-2 ratio determined before radiation therapy and clinical response in the patients, can be used as a biomarker to identify radiosensitive individuals. However, further studies are required to validate radiation-induced apoptotic biomarkers.

  9. Radiosensitization by SAHA in Experimental Colorectal Carcinoma Models-In Vivo Effects and Relevance of Histone Acetylation Status

    International Nuclear Information System (INIS)

    Folkvord, Sigurd; Ree, Anne Hansen; Furre, Torbjorn; Halvorsen, Thomas; Flatmark, Kjersti

    2009-01-01

    Purpose: Histone deacetylase inhibitors are being evaluated as antitumor agents in ongoing clinical trials, and promising preclinical results, combined with favorable toxicity profiles, have rendered the drugs as interesting candidates for combination with other treatment modalities, such as radiotherapy. The aim of the present study was to evaluate the radiosensitizing properties of suberoylanilide hydroxamic acid (SAHA) and the possible requirement of histone hyperacetylation at radiation exposure. Methods and materials: Radiosensitization by SAHA was assessed in a colorectal carcinoma cell line and in two colorectal xenograft models by analysis of clonogenic survival and tumor growth delay, respectively. Histone acetylation status at radiation exposure was evaluated by Western blot. Results: In vitro, radiosensitization was demonstrated when cells were preincubated with SAHA, and, in the xenografts, tumor growth was delayed when the mice were treated with fractionated radiation combined with daily SAHA injections compared with radiation alone. Surprisingly, the SAHA-dependent growth delay was still present when radiation was delivered at restored baseline acetylation levels compared with maximal histone hyperacetylation. Conclusion: SAHA was an effective radiosensitizer in experimental colorectal carcinoma models, suggesting that histone deacetylase inhibition might constitute a valuable supplement to current multimodal treatment strategies in rectal cancer. The presence of histone hyperacetylation at radiation was not required to obtain an increased radiation response, questioning the validity of using histone hyperacetylation as a molecular marker for radiosensitivity.

  10. AMRI-59 has a role of radiosensitizer via enhancement of γ-ionizing radiation-induced apoptotic cell death

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Wan Gi; Cho, Jeong Hyun; Kim, Ju Yeon; Hwang, Sang Gu; Um, Hong Duck; Park, Jong Kuk [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    Recent in vitro studies have suggested that may increase the invasiveness of some cancer cells (e.g., glioma, hepatocellular carcinoma, and pancreatic cancer cells) by stimulating several intracellular signaling pathways and in vivo studies have found that radiotherapy of primary tumor sites may promote metastasis. Thus, in addition to having therapeutic effects, IR might promote the malignant traits of surviving cancer cells. The existing efforts to develop radiosensitizing agents have focused on overcoming radioresistance and reducing damage to normal tissues. Recently, concepts of personalized- or precision medicine are developed due to advancement of mega data technique, which provide new targets to develop new anti-cancer drugs. In this study, we sought to identify the radiosensitizer effect of AMRI-59 in vitro and in vivo., which is recently developed specific inhibitor of peroxiredoxin (Prx) I. AMRI-59 enhanced radiation-induced cell death and its mean calculated dose enhancement ratio was 1.26. We also found combination of AMRI-59 and IR In a xenograft assay, the combined PHCM and radiation group showed 14.3 days of growth delay versus the control in terms of tumor growth. The enhancement factor of this combined treatment was determined to be 2.03.

  11. Catecholamines of the body tissues and radiosensitivity of rodents

    International Nuclear Information System (INIS)

    Grayevskaya, V.M.; Zolotariova, N.N.

    1975-01-01

    Various species of rodents are distinguished by their radiosensitivity (increasing): bank vole 57 Br mouse < golden hamster < BALB mouse < guinea pig. There is a positive correlation between radiosensitivity of these species and catecholamines content in the adrenals, urea and blood; and negative correlation between radiosensitivity and adrenaline and noradrenaline concentrations in liver and spleen cells. Presumable causes of this correlation, and the possibility of application of the index under study for predicting the organism radiosensitivity and forecasting the outcome of radiation damage are discussed

  12. Concurrent chemoradiotherapy with gemcitabine and cisplatin for pancreatic cancer: from the laboratory to the clinic

    International Nuclear Information System (INIS)

    Symon, Zvi; Davis, Mary; McGinn, Cornelius J.; Zalupski, Mark M.; Lawrence, Theodore S.

    2002-01-01

    Purpose: We have reported that gemcitabine and concurrent radiation is a promising therapy for patients with pancreatic cancer. We investigated whether the addition of cisplatin, which may increase the systemic efficacy of gemcitabine, would be synergistic with gemcitabine and/or radiation in human pancreatic cancer cell lines. Methods and Materials: BxPc3 and Panc-1 human pancreatic cancer cells were treated with three different schedules before radiation: (A) a sequential incubation of gemcitabine for 2 h followed by cisplatin for 2 h, (B) gemcitabine for 2 h, followed by washout of drug, replenishment of media for a 24-h incubation, followed by cisplatin for 2 h, and (C) gemcitabine for 24 h with a concurrent incubation of cisplatin for the last 2 h. Cells were assessed for clonogenic survival using a standard assay. Synergism was evaluated by the median effect analysis. Results: The schedule shown to be maximally synergistic for both cell lines was the consecutive 2-h gemcitabine, 2-h cisplatin exposure, particularly at surviving fractions of <0.5. Cisplatin did not produce radiosensitization nor did it affect gemcitabine-mediated radiosensitization. Conclusion: Cisplatin produces synergistic cytotoxicity with gemcitabine without compromising gemcitabine-mediated radiosensitization. On the basis of these laboratory and previous clinical observations, we have initiated a Phase I trial of cisplatin plus gemcitabine and radiotherapy in patients with unresectable pancreatic cancer

  13. Comparison of Individual Radiosensitivity to γ-Rays and Carbon Ions.

    Science.gov (United States)

    Shim, Grace; Normil, Marie Delna; Testard, Isabelle; Hempel, William M; Ricoul, Michelle; Sabatier, Laure

    2016-01-01

    Carbon ions are an up-and-coming ion species, currently being used in charged particle radiotherapy. As it is well established that there are considerable interindividual differences in radiosensitivity in the general population that can significantly influence clinical outcomes of radiotherapy, we evaluate the degree of these differences in the context of carbon ion therapy compared with conventional radiotherapy. In this study, we evaluate individual radiosensitivity following exposure to carbon-13 ions or γ-rays in peripheral blood lymphocytes of healthy individuals based on the frequency of ionizing radiation (IR)-induced DNA double strand breaks (DSBs) that was either misrepaired or left unrepaired to form chromosomal aberrations (CAs) (simply referred to here as DSBs for brevity). Levels of DSBs were estimated from the scoring of CAs visualized with telomere/centromere-fluorescence in situ hybridization (TC-FISH). We examine radiosensitivity at the dose of 2 Gy, a routinely administered dose during fractionated radiotherapy, and we determined that a wide range of DSBs were induced by the given dose among healthy individuals, with highly radiosensitive individuals harboring more IR-induced breaks in the genome than radioresistant individuals following exposure to the same dose. Furthermore, we determined the relative effectiveness of carbon irradiation in comparison to γ-irradiation in the induction of DSBs at each studied dose (isodose effect), a quality we term "relative dose effect" (RDE). This ratio is advantageous, as it allows for simple comparison of dose-response curves. At 2 Gy, carbon irradiation was three times more effective in inducing DSBs compared with γ-irradiation (RDE of 3); these results were confirmed using a second cytogenetic technique, multicolor-FISH. We also analyze radiosensitivity at other doses (0.2-15 Gy), to represent hypo- and hyperfractionation doses and determined that RDE is dose dependent: high ratios at low doses

  14. Intracavitary irradiation of early rectal cancer for cure. A series of 186 cases

    International Nuclear Information System (INIS)

    Papillon, J.

    1975-01-01

    If radical surgery is the only rational policy for most cases of rectal cancer, the problem of local treatment in poor surgical risk patients should be discussed in selected cases. Only limited, fairly-well-differentiated tumors, still confined to the rectal wall may have a sufficiently low probability of lymphatic spread to be amenable to local treatment. Rectal cancer, usually regarded as being slightly radiosensitive when treated by external irradiation, proves to be highly radiosensitive in the case of early cancer treated by intracavitary irradiation. This method is able to control a large amount of limited polypoid and ulcerative adenocarcinomas. In a series of 133 cases followed more than 5 years, the rate of death from cancer is only 9 percent, and the 5-year survival rate is 78 percent. As compared with local excision or electrocoagulation, intracavitary irradiation has several advantages. It does not require colostomy nor anesthesia. Contact x-ray therapy is an ambulatory treatment applicable even to elderly and fragile patients. There is no danger of fistula in the case of tumor of the anterior wall in female patients. It preserves all the chances of cure by subsequent surgery in case of failure. (auth)

  15. Potential predictive assay using RAR-β for radiosensitization by 13-cis-retinoic acid and interferonα2a in human carcinoma cells

    International Nuclear Information System (INIS)

    Ryu, Samuel; Nevaldine, Barbara H.; Unguraneau, Carmen; Chung, Chung T.; King, Gerald A.; Stein, Joseph P.

    1997-01-01

    Purpose: Cell culture studies have shown increased cytotoxicity and inhibition of cell proliferation by combined use of 13-cis-retinoic acid (CRA) and interferon-α2a (IFN). Clinically, a direct antitumor activity has been observed by combined use of CRA and IFN in patients with cancer of the cervix and skin. Since IFN is known to enhance radiation response in selected human carcinoma cell lines, we carried out a series of experiments in an effort to improve the efficacy of radiation therapy by CRA and IFN in combination. Materials and Methods: Human cervical carcinoma ME-180 and HeLa cell lines were exposed to 10 μM CRA and 1000 unit/ml IFN in combination for 48 hours prior to radiation. Endpoint of radiosensitization study was colony-forming ability of single cells. Retinoic acid receptors (RAR and RXR) were detected by RNAse protection assay. Apoptosis was quantitated by using immunohistochemical staining method (Apop Tag). The cells were also transfected with bcl-2 or RAR-β gene to explore the mechanism of radiation-induced cell killing. Results: A substantial radiosensitization was observed by the combined use of CRA and IFN in human cervical carcinoma ME-180 cells in culture. The radiation enhancement ratio was 2.0 at 1% cell survival level. The principal mode of radiation-induced cell killing was apoptosis since more than 90% of the ME-180 cells showed evidence of apoptosis by combined treatment of CRA, IFN, and radiation. Both apoptosis and radiosensitization were blocked by transfecting bcl-2 gene into ME-180 cells. In contrast to these results with ME-180 cells, no radiosensitization was observed in HeLa cells by CRA and IFN under the same experimental conditions. Both cell lines express various RXR and RAR mRNAs. However, the RAR-β was undetectable in HeLa cells but present at high levels in ME-180 cells, as determined by RNAse protection assay. Because of this differential expression of RAR-β mRNA, we hypothesized that RAR-β may mediate the

  16. Unique proteomic signature for radiation sensitive patients; a comparative study between normo-sensitive and radiation sensitive breast cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Skiöld, Sara [Center for Radiation Protection Research, Department of Molecular Biosciences, The Wernner-Gren Institute, Stockholm University, Stockholm (Sweden); Azimzadeh, Omid [Institute of Radiation Biology, German Research Center for Environmental Health, Helmholtz Zentrum München (Germany); Merl-Pham, Juliane [Research Unit Protein Science, German Research Center for Environmental Health, Helmholtz Zentrum München, Neuherberg (Germany); Naslund, Ingemar; Wersall, Peter; Lidbrink, Elisabet [Division of Radiotherapy, Radiumhemmet, Karolinska University Hospital, Stockholm (Sweden); Tapio, Soile [Institute of Radiation Biology, German Research Center for Environmental Health, Helmholtz Zentrum München (Germany); Harms-Ringdahl, Mats [Center for Radiation Protection Research, Department of Molecular Biosciences, The Wernner-Gren Institute, Stockholm University, Stockholm (Sweden); Haghdoost, Siamak, E-mail: Siamak.Haghdoost@su.se [Center for Radiation Protection Research, Department of Molecular Biosciences, The Wernner-Gren Institute, Stockholm University, Stockholm (Sweden)

    2015-06-15

    Highlights: • The unique protein expression profiles were found that separate radiosensitive from normal sensitive breast cancer patients. • The oxidative stress response, coagulation properties and acute phase response suggested to be the hallmarks of radiation sensitivity. - Abstract: Radiation therapy is a cornerstone of modern cancer treatment. Understanding the mechanisms behind normal tissue sensitivity is essential in order to minimize adverse side effects and yet to prevent local cancer reoccurrence. The aim of this study was to identify biomarkers of radiation sensitivity to enable personalized cancer treatment. To investigate the mechanisms behind radiation sensitivity a pilot study was made where eight radiation-sensitive and nine normo-sensitive patients were selected from a cohort of 2914 breast cancer patients, based on acute tissue reactions after radiation therapy. Whole blood was sampled and irradiated in vitro with 0, 1, or 150 mGy followed by 3 h incubation at 37 °C. The leukocytes of the two groups were isolated, pooled and protein expression profiles were investigated using isotope-coded protein labeling method (ICPL). First, leukocytes from the in vitro irradiated whole blood from normo-sensitive and extremely sensitive patients were compared to the non-irradiated controls. To validate this first study a second ICPL analysis comparing only the non-irradiated samples was conducted. Both approaches showed unique proteomic signatures separating the two groups at the basal level and after doses of 1 and 150 mGy. Pathway analyses of both proteomic approaches suggest that oxidative stress response, coagulation properties and acute phase response are hallmarks of radiation sensitivity supporting our previous study on oxidative stress response. This investigation provides unique characteristics of radiation sensitivity essential for individualized radiation therapy.

  17. Unique proteomic signature for radiation sensitive patients; a comparative study between normo-sensitive and radiation sensitive breast cancer patients

    International Nuclear Information System (INIS)

    Skiöld, Sara; Azimzadeh, Omid; Merl-Pham, Juliane; Naslund, Ingemar; Wersall, Peter; Lidbrink, Elisabet; Tapio, Soile; Harms-Ringdahl, Mats; Haghdoost, Siamak

    2015-01-01

    Highlights: • The unique protein expression profiles were found that separate radiosensitive from normal sensitive breast cancer patients. • The oxidative stress response, coagulation properties and acute phase response suggested to be the hallmarks of radiation sensitivity. - Abstract: Radiation therapy is a cornerstone of modern cancer treatment. Understanding the mechanisms behind normal tissue sensitivity is essential in order to minimize adverse side effects and yet to prevent local cancer reoccurrence. The aim of this study was to identify biomarkers of radiation sensitivity to enable personalized cancer treatment. To investigate the mechanisms behind radiation sensitivity a pilot study was made where eight radiation-sensitive and nine normo-sensitive patients were selected from a cohort of 2914 breast cancer patients, based on acute tissue reactions after radiation therapy. Whole blood was sampled and irradiated in vitro with 0, 1, or 150 mGy followed by 3 h incubation at 37 °C. The leukocytes of the two groups were isolated, pooled and protein expression profiles were investigated using isotope-coded protein labeling method (ICPL). First, leukocytes from the in vitro irradiated whole blood from normo-sensitive and extremely sensitive patients were compared to the non-irradiated controls. To validate this first study a second ICPL analysis comparing only the non-irradiated samples was conducted. Both approaches showed unique proteomic signatures separating the two groups at the basal level and after doses of 1 and 150 mGy. Pathway analyses of both proteomic approaches suggest that oxidative stress response, coagulation properties and acute phase response are hallmarks of radiation sensitivity supporting our previous study on oxidative stress response. This investigation provides unique characteristics of radiation sensitivity essential for individualized radiation therapy

  18. Catecholamines of the body tissues and radiosensitivity of rodents

    Energy Technology Data Exchange (ETDEWEB)

    Grayevskaya, V M; Zolotariova, N N [AN SSSR, Moscow. Inst. Morfologii Zhivotnykh

    1975-01-01

    Various species of rodents are distinguished by their radiosensitivity (increasing): bank vole < Wistar rat < wild mouse < CC/sub 57/Br mouse < golden hamster < BALB mouse < guinea pig. There is a positive correlation between radiosensitivity of these species and catecholamines content in the adrenals, urea and blood; and negative correlation between radiosensitivity and adrenaline and noradrenaline concentrations in liver and spleen cells. Presumable causes of this correlation, and the possibility of application of the index under study for predicting the organism radiosensitivity and forecasting the outcome of radiation damage are discussed.

  19. Radiosensitivity of carcinoma of esophagus

    International Nuclear Information System (INIS)

    Furusawa, Hidenori

    1986-01-01

    With a detailed graphic reconstruction of radiation effects shown in 11 operation materials of carcinoma of esophagus with preoperative irradiation, histologic analysis of the radiosensitivity was made. Residual cancer lesions in 11 operation specimens contained adenocarcinoma elements. Carcinoma of esophagus belonged to mixed carcinoma (syn. metaplastic cancer). Radioresistant nature resulted from the remnant adenocarcinoma elements. Protruded type (3 cases) showed about 60 % of residual cancer after preoperative irradiation of 40 Gy (Lineac or 60 Co.). The residual cancer nests histologically revealed well-differentiated squamous cell carcinoma with a few signet-ring cells, compatible with mucoepidermoid carcinoma. In protruded type, the mixed carcinoma was composed of segmental, disproportioned zonal squamous metaplasia. As its histogenetic origin, a main duct of esophageal gland was suggested. In 9 autopsy cases of esophageal cancer, recurrent lesion within the field of irradiation failed to respond to radiotherapy. In recurrent residual lesions, a higher proportion of adenocarcinoma elements was noticed. Therefore, the cancer part formed by a high rate of metaplasia was markedly responsive to irradiation, whereas increased residue of adenocarcinoma elements was enhanced the radioresistant property. In a middle thoracic esophagus (Im) corresponding to the commonest site of esophageal cancer, the distribution of esohageal glands was in a high density with a constant ratio of density in each age group particularly in male. In age groups with higher incidence of carcinoma of esophagus, esophageal glands markedly increased especially in male, in contrast with the indefinite number and density ratio in female cases. A high density of esophageal glands was noticed in the upper (Iu) and lower (Im) parts of the 2nd physiologic constriction, in proportion to the commonest site of carcinoma of esophagus. (J.P.N.)

  20. The influence of metformin as a radiosensitizer of cells submitted to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Gonçalves, Letícia S.; Pereira, Alline G.; Gerolis, Luanai G.L.; Filho, Jamilson N.R.; Neves, Maria J., E-mail: lsatlergoncalves@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizontge, MG (Brazil). Lab. de Radiobiologia

    2017-07-01

    In recent years, due to the high prevalence of type 2 diabetes, the pharmacological therapy with metformin has become one of the most prescribed medications worldwide, with approximately 150 million people currently in use. Several studies have reflected the relevance of this fact, indicating that this extensively used drug may play another important role: it has been reported that metformin could be responsible for decreasing cancer incidence and mortality in diabetic patients. However, the mechanism by which its antineoplastic effect occurs remains unclear. The term cancer refers to not only one single disease, but to hundreds of them, grouped under the same name. Even in one specific organ, different types of malignant cells can possibly develop. Radiotherapy, one of the most effective ways to combat many cancers, is based on the formation of free radicals through the radiolysis of water molecules on the affected area, caused by ionizing irradiation. The objective of this work was to study if the treatment with metformin can influence the effect caused by ionizing radiation on cells, using the yeast Saccharomyces cerevisiae as an experimental model for cancer. In other words, this work aims to analyze if metformin acts as a radiosensitizer of tumor cells. This can represent a possible strategy as a therapeutic combination to be explored in the war against cancer. (author)

  1. The influence of metformin as a radiosensitizer of cells submitted to gamma radiation

    International Nuclear Information System (INIS)

    Gonçalves, Letícia S.; Pereira, Alline G.; Gerolis, Luanai G.L.; Filho, Jamilson N.R.; Neves, Maria J.

    2017-01-01

    In recent years, due to the high prevalence of type 2 diabetes, the pharmacological therapy with metformin has become one of the most prescribed medications worldwide, with approximately 150 million people currently in use. Several studies have reflected the relevance of this fact, indicating that this extensively used drug may play another important role: it has been reported that metformin could be responsible for decreasing cancer incidence and mortality in diabetic patients. However, the mechanism by which its antineoplastic effect occurs remains unclear. The term cancer refers to not only one single disease, but to hundreds of them, grouped under the same name. Even in one specific organ, different types of malignant cells can possibly develop. Radiotherapy, one of the most effective ways to combat many cancers, is based on the formation of free radicals through the radiolysis of water molecules on the affected area, caused by ionizing irradiation. The objective of this work was to study if the treatment with metformin can influence the effect caused by ionizing radiation on cells, using the yeast Saccharomyces cerevisiae as an experimental model for cancer. In other words, this work aims to analyze if metformin acts as a radiosensitizer of tumor cells. This can represent a possible strategy as a therapeutic combination to be explored in the war against cancer. (author)

  2. Radiosensitization of C225 on human non-small cell lung cancer cell line H-520

    International Nuclear Information System (INIS)

    Zhang Yingdong; Wang Junjie; Liu Feng; Zhao Yong

    2008-01-01

    Objective: To investigate the efficacy of C225 (cetuximab), a chimeric human-mouse anti-epithelial growth factor receptor monoclonal antibody, combined with 60 Co gamma irradiation against human non-small cell lung cancer cell line H-520. Methods: H-520 cells were treated either with different dose of 60 Co irradiation (1,2,4,6,8 and 10 Gy)alone or together with C225 (100 nmol/L). Colony forming capacity was determined to create the survival curve 10 days after the treatment. Cells in different groups were harvested 72 hours after irradiation for apoptosis analysis or 48 hours after irradiation for cell cycle analysis by flow cytometry assay. Results: The clone number in combinational treatment group was less than that in irradiation only group, which suggested that the cell survival rate in the combinational treatment group was significantly decreased comparing with irradiation only group (F=6.36, P O + G 1 phases for C225 treatment, in G 2 + M phases for 60 Co irradiation, and in both G 0 + G 1 and G 2 + M phases for C225 in combination with 60 Co irradiation. Conclusions: C225 has radiosensitizing effects on H-520 cells, which may through the enhancement of 60 Co irradiation-induced cell death and cell cycle arrest. This study provides a supportive evidence for clinical treatment in non-small cell lung cancer. (authors)

  3. Studies of metronidazole radiosensitizing effect in radiation treatment of patients with oral cavity cancer

    International Nuclear Information System (INIS)

    Polyakov, P.Yu.; Daryalova, S.L.; Pelevina, I.I.; Karakulov, R.K.; Zel'vin, B.M.; Kiseleva, E.S.; Kvasov, V.A.

    1985-01-01

    Clinical observations of 26 patients with tongue, oral cavity and oropharyngeal cancer receiving telegammatherapy by dynamic dose fractionation scheme in combination with metronidazole (MZ), and of 38 patients from the control group treated using the identical schedule without MZ suggest that MZ favors increasing radiation damage in tumors in those sites without changing the character or intensifying early radiation reactions. After oral administration of MZ in single doses of 5-6 g/m 2 it reached its maximum in the blood serum within 2-4 h. When the total dose of 30-60 g of MZ was used, a marked toxic effect manifest in gastrointestinal symptoms was observed in 33.3% of patients. MZ has a negative effect on liver functions; however, changes in biochemical tests were reversible and within normal values. Simultaneous studies of biopsy material from 22 patients (11 from each group) in terms of proliferation activity showed that oral cavity tumors contain a significant portion of proliferating cells which notably decrease in the course of radiation therapy. The decrease is marked to a greater extent after irradiation in combination with MZ. (author)

  4. Evaluation of a MTT assay in measurement of radiosensitizing effect

    International Nuclear Information System (INIS)

    Higuchi, Keiko; Mitsuhashi, Norio; Saitoh, Jun-ichi; Maebayashi, Katsuya; Sakurai, Hideyuki; Akimoto, Tetsuo; Niibe, Hideo

    1999-01-01

    The usefulness of a MTT assay by measuring the radiosensitizing effect of caffeine on rat yolk sac tumor cell line with a mutant-type p53 in vitro was evaluated. A rat yolk sac tumor cell line with a mutant-type p53, NMT-1R, was used in this study. The radiosensitivity of NMT-1R with or without caffeine was measured with a MTT assay. The results were compared with those by a clonogenic assay. Caffeine at a concentration of 2.0 mM which released radiation-induced G 2 block demonstrated a radiosensitizing effect, but caffeine at a concentration of 0.5 mM did not. The radiosensitizing effect of caffeine measured by a MTT assay correlated with that measured by a clonogenic assay. A MTT assay was useful to measure radiosensitivity and/or a radiosensitizing effect in vitro. (author)

  5. Radiosensitivity of peripheral blood lymphocytes in autoimmune disease

    Energy Technology Data Exchange (ETDEWEB)

    Harris, G [Kennedy Inst. of Rheumatology, London (UK). Div. of Experimental Pathology; Cramp, W A; Edwards, J C; George, A M; Sabovljev, S A; Hart, L; Hughes, G R.V. [Hammersmith Hospital, London (UK); Denman, A M [Northwich Park Hospital, Harrow (UK); Yatvin, M B [Wisconsin Clinical Cancer Center, Madison (USA)

    1985-06-01

    The proliferation of peripheral blood lymphocytes, cultured with Con A, can be inhibited by ionizing radiation. Lymphocytes from patients with conditions associated with autoimmunity, such as rheumatoid arthritis, systemic lupus erythematosus and polymyositis, are more radiosensitive than those from healthy volunteers or patients with conditions not associated with autoimmunity. Nuclear material isolated from the lymphocytes of patients with autoimmune diseases is, on average, lighter in density than the nuclear material from most healthy controls. This difference in density is not related to increased sensitivity to ionizing radiation but the degree of post-irradiation change in density (lightening) is proportional to the initial density, i.e. more dense nuclear material always shows a greater upward shift after radiation. The recovery of pre-irradiation density of nuclear material, 1 h after radiation exposure, taken as an indication of DNA repair, correlates with the radiosensitivity of lymphocyte proliferation (Con A response); failure to return to pre-irradiation density being associated with increased sensitivity of proliferative response. These results require extension but, taken with previously reported studied of the effects of DNA methylating agents, support the idea that DNA damage and its defective repair could be important in the aetio-pathogenesis of autoimmune disease.

  6. Coculture with astrocytes reduces the radiosensitivity of glioblastoma stem-like cells and identifies additional targets for radiosensitization

    International Nuclear Information System (INIS)

    Rath, Barbara H; Wahba, Amy; Camphausen, Kevin; Tofilon, Philip J

    2015-01-01

    Toward developing a model system for investigating the role of the microenvironment in the radioresistance of glioblastoma (GBM), human glioblastoma stem-like cells (GSCs) were grown in coculture with human astrocytes. Using a trans-well assay, survival analyses showed that astrocytes significantly decreased the radiosensitivity of GSCs compared to standard culture conditions. In addition, when irradiated in coculture, the initial level of radiation-induced γH2AX foci in GSCs was reduced and foci dispersal was enhanced suggesting that the presence of astrocytes influenced the induction and repair of DNA double-strand breaks. These data indicate that astrocytes can decrease the radiosensitivity of GSCs in vitro via a paracrine-based mechanism and further support a role for the microenvironment as a determinant of GBM radioresponse. Chemokine profiling of coculture media identified a number of bioactive molecules not present under standard culture conditions. The gene expression profiles of GSCs grown in coculture were significantly different as compared to GSCs grown alone. These analyses were consistent with an astrocyte-mediated modification in GSC phenotype and, moreover, suggested a number of potential targets for GSC radiosensitization that were unique to coculture conditions. Along these lines, STAT3 was activated in GSCs grown with astrocytes; the JAK/STAT3 inhibitor WP1066 enhanced the radiosensitivity of GSCs under coculture conditions and when grown as orthotopic xenografts. Further, this coculture system may also provide an approach for identifying additional targets for GBM radiosensitization

  7. Increased radiosensitivity of HPV-positive head and neck cancer cell lines due to cell cycle dysregulation and induction of apoptosis

    International Nuclear Information System (INIS)

    Arenz, Andrea; Ziemann, Frank; Wittig, Andrea; Preising, Stefanie; Engenhart-Cabillic, Rita; Mayer, Christina; Wagner, Steffen; Klussmann, Jens-Peter; Wittekindt, Claus; Dreffke, Kirstin

    2014-01-01

    Human Papillomavirus (HPV)-related head and neck squamous cell carcinoma (HNSCC) respond favourably to radiotherapy as compared to HPV-unrelated HNSCC. We investigated DNA damage response in HPV-positive and HPV-negative HNSCC cell lines aiming to identify mechanisms, which illustrate reasons for the increased sensitivity of HPV-positive cancers of the oropharynx. Radiation response including clonogenic survival, apoptosis, DNA double-strand break (DSB) repair, and cell cycle redistribution in four HPV-positive (UM-SCC-47, UM-SCC-104, 93-VU-147T, UPCI:SCC152) and four HPV-negative (UD-SCC-1, UM-SCC-6, UM-SCC-11b, UT-SCC-33) cell lines was evaluated. HPV-positive cells were more radiosensitive (mean SF2: 0.198 range: 0.22-0.18) than HPV-negative cells (mean SF2: 0.34, range: 0.45-0.27; p = 0.010). Irradiated HPV-positive cell lines progressed faster through S-phase showing a more distinct accumulation in G2/M. The abnormal cell cycle checkpoint activation was accompanied by a more pronounced increase of cell death after x-irradiation and a higher number of residual and unreleased DSBs. The enhanced responsiveness of HPV-related HNSCC to radiotherapy might be caused by a higher cellular radiosensitivity due to cell cycle dysregulation and impaired DNA DSB repair. (orig.) [de

  8. Local-regional control in breast cancer patients with a possible genetic predisposition

    International Nuclear Information System (INIS)

    Freedman, Laura M.; Buchholz, Thomas A.; Thames, Howard D.; Strom, Eric A.; McNeese, Marsha D.; Hortobagyi, Gabriel N.; Singletary, S. Eva; Heaton, Keith M.; Hunt, Kelly K.

    2000-01-01

    %, respectively. Conclusions: Patients with a possible genetic predisposition to breast cancer had low 5-year rates of local recurrence when treated with breast conserving surgery and radiation, but the local failure rate exceeded 50% when radiation was omitted. Our data are consistent with the hypothesis that patients with an underlying genetic predisposition develop cancers with radiosensitive phenotypes

  9. Development of Radiosensitizer using farnesyltransferase inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Jong Seok; Choe, Yong Kyung; Han, Mi Young; Kim, Kwang Dong [Korea Research Institute of Bioscience and Biotechnology, Taejon (Korea)

    1999-03-01

    We selected some compounds that were reported to have an activity of farneyltransferase inhibitor and tested the hypothesis that they might be used to radiosensitize cells transformed by ras oncogenes. The inhibition of ras processing using some, but not all, inhibitors resulted in higher levels of cell death after {gamma}-irradiation and increased radiosensitivity in H-ras-transformed NIH3T3 cells and MCF-10A human tumor cells. They did not induce additional cell death in control cells that doe not have ras mutation. Furthermore, the treatment of inhibitors alone induced a weak G0/G1 block, whereas inhibitors in combination with {gamma}-irradiation induced an additional enrichment in the G2/M phase of the cell cycle that typically represents irradiation-induced growth arrest. At present, the underling mechanism by which the farnesylltransferase inhibitors exert radiosensitizing effect is not known. In summary, our results suggest and lead to the possibility that some of farnesylation inhibitors may prove clinically useful not only as antitumor agents, but also radiosensitizers of tumors whose growth is dependent on ras function. (author). 15 refs., 10 figs., 4 tabs.

  10. Differences in radiosensitivity among cells in culture and in experimental tumours: Significance for the effectiveness of human cancer therapy

    International Nuclear Information System (INIS)

    Barendsen, G.W.; Amsterdam Univ.

    1987-01-01

    Problems in the application of radiobiological data on various types of models, cell in vitro, experimental tumours, and clinical models, to the prediction of tumour radiocurability are discussed. On the basis of observations on cells in culture and experimental tumours it is suggested that heterogeneity in responsiveness of tumours in patients is caused in a large part by differences in intrinsic cellular radiosensitivity. Methods and developments are reviewed, which may yield better assays for the prediction of tumour responsiveness to treatments. (Auth.)

  11. Photosensitizers and radiosensitizers in dermatology and oncology

    International Nuclear Information System (INIS)

    Bruckner, V.

    1979-01-01

    Two therapeutic modalities are currently of great interest, namely photo- and radiosensitization. Whereas photosensitizers only function in combination with ultraviolet (UV) light, radiosensitizers act only in combination with ionizing radiation. Because of the small UV penetration, up to a maximum of 0,5 mm, photosensitization can take place only at the surface of the body, i.e. the skin. Photosensitizers are applied in dermatology in order to optimize and improve the UV therapy of certain diseases (mainly psoriasis, mycosis fungoides and vitiligo). Radiosensitizers lead to an increase in sensitivity of the hypoxic and therefore radioresistant parts of tumours against X- and gamma-radiation. With sufficient concentration within the tumour, they can act where the radiation can reach, even in the deeper parts of the body. They represent a modern and useful aid to radiation oncology. Because of neurotoxic effects, however, their practical use is limited. A short review of the history, mechanisms of action, application and side-effects of these photo- and radiosensitizers is presented

  12. Photosensitizers and radiosensitizers in dermatology and oncology

    Energy Technology Data Exchange (ETDEWEB)

    Bruckner, V [Stellenbosch University, Parowvallei (South Africa). Departments of Medical Physics and Radiology

    1979-09-22

    Two therapeutic modalities are currently of great interest, namely photo- and radiosensitization. Whereas photosensitizers only function in combination with ultraviolet (UV) light, radiosensitizers act only in combination with ionizing radiation. Because of the small UV penetration, up to a maximum of 0,5 mm, photosensitization can take place only at the surface of the body, i.e. the skin. Photosensitizers are applied in dermatology in order to optimize and improve the UV therapy of certain diseases (mainly psoriasis, mycosis fungoides and vitiligo). Radiosensitizers lead to an increase in sensitivity of the hypoxic and therefore radioresistant parts of tumours against X- and gamma-radiation. With sufficient concentration within the tumour, they can act where the radiation can reach, even in the deeper parts of the body. They represent a modern and useful aid to radiation oncology. Because of neurotoxic effects, however, their practical use is limited. A short review of the history, mechanisms of action, application and side-effects of these photo- and radiosensitizers is presented.

  13. Fanconi's anemia and clinical radiosensitivity. Report on two adult patients with locally advanced solid tumors treated by radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Bremer, M.; Karstens, J.H. [Hannover Medical School, Hannover (Germany). Dept. of Radiation Oncology; Schindler, D.; Gross, M. [Univ. Wuerzburg (Germany). Inst. of Human Genetics; Doerk, T. [Hannover Medical School, Hannover (Germany). Dept. of Obstetrics and Gynecology; Morlot, S. [Hannover Medical School, Hannover (Germany). Inst. of Human Genetics

    2003-11-01

    Background: Patients with Fanconi's anemia (FA) may exhibit an increased clinical radiosensitivity of various degree, although detailed clinical data are scarce. We report on two cases to underline the possible challenges in the radiotherapy of FA patients. Case Report and Results: Two 24- and 32-year-old male patients with FA were treated by definitive radiotherapy for locally advanced squamous cell head and neck cancers. In the first patient, long-term tumor control could be achieved after delivery of 67 Gy with a - in part - hyperfractionated split-course treatment regimen and, concurrently, one course of carboplatin followed by salvage neck dissection. Acute toxicity was marked, but no severe treatment-related late effects occurred. 5 years later, additional radiotherapy was administered due to a second (squamous cell carcinoma of the anus) and third (squamous cell carcinoma of the head and neck) primary, which the patient succumbed to. By contrast, the second patient experienced fatal acute hematologic toxicity after delivery of only 8 Gy of hyperfractionated radiotherapy. While the diagnosis FA could be based on flow cytometric analysis of a lymphocyte culture in the second patient, the diagnosis in the first patient had to be confirmed by hypersensitivity to mitomycin of a fibroblast cell line due to complete somatic lymphohematopoietic mosaicism. In this patient, phenotype complementation and molecular genetic analysis revealed a pathogenic mutation in the FANCA gene. The first patient has not been considered to have FA until he presented with his second tumor. Conclusion: FA has to be considered in patients presenting at young age with squamous cell carcinoma of the head and neck or anus. The diagnosis FA is of immediate importance for guiding the optimal choice of treatment. Radiotherapy or even radiochemotherapy seems to be feasible and effective in individual cases. (orig.)

  14. The selection of patients for accelerated radiotherapy on the basis of tumor growth kinetics and intrinsic radiosensitivity

    International Nuclear Information System (INIS)

    Tucker, S.L.; Kang-Sow Chan

    1990-01-01

    Mathematical modelling was used to reach qualitative conclusions concerning the relative rate of local tumor control that might be achieved by using accelerated fractionation to treat only the patients with the most rapidly growing rumors, compared with the control rated that could be expected from either conventional or accelerated radiotherapy alone. The results suggest that concomitant boost therapy is equally or more effective than conventional dose fractionation for all tumors, regardless of their growth kinetics. For tumors with very short clonogen doubling times, CHART (continuous hyperfractionated accelerated radiotherapy) may be even more effective than concomitant boost treatment, but CHART is less effective than conventional or concomitant boost therapy for tumors with longer clonogen doubling times. Thus, there is a rationale for using a predictive assay of tumor clonogen doubling times to identify the patients who should be treated with CHART. However, improvements in local tumor control resulting from concomitant boost treatment or the selective use of CHART are not likely to be apparent in the population as a whole, because the overall control rated are largely determined by refractory tumors having little chance of control with any of the treatments and by higher responsive tumors that are likely to be controlled regardless of the treatment choice. Differences in control rated with different treatment strategies are most apparent in the stochastic fraction of the population, which excludes those patients for whom there is either very little change (e.g. 99%) of achieving local control with both treatments. The stochastic fraction can be approximated by excluding those patients with the most radioresistant and the most radiosensitive tumors, since intrinsic tumor radiosensitivity appears to be the single most important factor determining treatment outcome. (author). 32 refs.; 4 figs.; 5 tabs

  15. Effects of propranolol in combination with radiation on apoptosis and survival of gastric cancer cells in vitro

    International Nuclear Information System (INIS)

    Liao, Xinhua; Che, Xiangming; Zhao, Wei; Zhang, Danjie; Long, Houlong; Chaudhary, Prakash; Li, Haijun

    2010-01-01

    The National Comprehensive Cancer Network (NCCN) guidelines recommend radiotherapy as a standard treatment for patients with a high risk of recurrence in gastric cancer. Because gastric cancer demonstrates limited sensitivity to radiotherapy, a radiosensitizer might therefore be useful to enhance the radiosensitivity of patients with advanced gastric carcinoma. In this study, we evaluated if propranolol, a β-adrenoceptor (β-AR) antagonist, could enhance radiosensitivity and explored its precise molecular mechanism in gastric cancer cells. Human gastric adenocarcinoma cell lines (SGC-7901 and BGC-823) were treated with or without propranolol and exposed to radiation. Cell viability and clonogenic survival assays were performed, and cell apoptosis was evaluated with flow cytometry. In addition, the expression of nuclear factor κB (NF-κB), vascular endothelial growth factor (VEGF), cyclooxygenase 2 (COX-2), and epidermal growth factor receptor (EGFR) were detected by western blot and real-time reverse transcription polymerase chain reaction (PCR). Propranolol combined with radiation decreased cell viability and clonogenic survivability. Furthermore, it also induced apoptosis in both cell lines tested, as determined by Annexin V staining. In addition, treatment with propranolol decreased the level of NF-κB and, subsequently, down-regulated VEGF, COX-2, and EGFR expression. Taken together, these results suggested that propranolol enhanced the sensitivity of gastric cancer cells to radiation through the inhibition of β-ARs and the downstream NF-κB-VEGF/EGFR/COX-2 pathway

  16. Inhibition of autophagy induced by TSA sensitizes colon cancer cell to radiation.

    Science.gov (United States)

    He, Gang; Wang, Yan; Pang, Xueli; Zhang, Bo

    2014-02-01

    Radiotherapy is one of the main treatments for clinical cancer therapy. However, its application was limited due to lack of radiosensitivity in some cancers. Trichostatin A (TSA) is a classic histone deacetylases inhibitor (HDACi) that specifically inhibits the biochemical functions of HDAC and is demonstrated to be an active anticancer drug. However, whether it could sensitize colon cancer to radiation is not clear. Our results showed that TSA enhanced the radiosensitivity of colon cancer cells as determined by CCK-8 and clonogenic survival assay. Moreover, apoptotic cell death induced by radiation was enhanced by TSA treatment. Additionally, TSA also induced autophagic response in colon cancer cells, while autophagy inhibition led to cell apoptosis and enhanced the radiosensitivity of colon cancer cells. Our data suggested that inhibition of cytoprotective autophagy sensitizes cancer cell to radiation, which might be further investigated for clinical cancer radiotherapy.

  17. Enhancement of radiotherapy efficacy by miR-200c-loaded gelatinase-stimuli PEG-Pep-PCL nanoparticles in gastric cancer cells

    Directory of Open Access Journals (Sweden)

    Cui FB

    2014-05-01

    Full Text Available Fang-bo Cui,1,* Qin Liu,1,* Ru-Tian Li,1 Jie Shen,1 Pu-yuan Wu,1 Li-Xia Yu,1 Wen-jing Hu,1 Feng-lei Wu,2 Chun-Ping Jiang,1 Guo-feng Yue,2 Xiao-Ping Qian,1 Xi-Qun Jiang,3 Bao-Rui Liu11The Comprehensive Cancer Center of Drum-Tower Hospital, Medical School of Nanjing University and Clinical Cancer Institute of Nanjing University, Nanjing, 2Nanjing Medical University, 3Laboratory of Mesoscopic Chemistry and Department of Polymer Science and Engineering, College of Chemistry and Chemical Engineering, Nanjing University, Nanjing, People's Republic of China*These authors contributed equally to this workAbstract: Radiotherapy is the main locoregional control modality for many types of unresectable tumors, including gastric cancer. However, many patients fail radiotherapy due to intrinsic radioresistance of cancer cells, which has been found to be strongly associated with cancer stem cell (CSC-like properties. In this study, we developed a nanoparticle formulation to deliver miR-200c, which is reported to inhibit CSC-like properties, and then evaluated its potential activity as a radiosensitizer. miR-200c nanoparticles significantly augmented radiosensitivity in three gastric cancer cell lines (sensitization enhancement ratio 1.13–1.25, but only slightly in GES-1 cells (1.06. In addition to radioenhancement, miR-200c nanoparticles reduced the expression of CD44, a putative CSC marker, and the percentage of CD44+ BGC823 cells. Meanwhile, other CSC-like properties, including invasiveness and resistance to apoptosis, could be suppressed by miR-200c nanoparticles. CSC-associated radioresistance mechanisms, involving reactive oxygen species levels and DNA repair capacity, were also attenuated. We have demonstrated that miR-200c nanoparticles are an effective radiosensitizer in gastric cancer cells and induce little radiosensitization in normal cells, which suggests that they are as a promising candidate for further preclinical and clinical evaluation

  18. Tumour radiosensitization with the halogenated pyrimidines 5'-bromo-and 5'-iododeoxyuridine

    International Nuclear Information System (INIS)

    Epstein, A.H.; Cook, J.A.; Goffman, T.; Glatstein, E.

    1993-01-01

    The authors review studies of the use of iododeoxyuridine (IdUrd) and bromodeoxyuridine as radiosensitizers and attempt to correlate the clinical outcome for patients treated with radiation and IdUrd with the extent of halogenated pyrimidine cellular uptake and incorporation. (U.K.)

  19. Radiosensitization effects of sorafenib on colon cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Ho; Kim, Mi-Sook; Jung, Won-Gyun; Jeong, Youn Kyoung [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2014-11-15

    Radiotherapy is a standard therapy in the adjuvant treatment of resected colon and rectum cancers, and its combination with chemotherapy has been shown to reduce local failure and distant metastasis still further, thereby improving the outcome of treatment. One potential chemotherapeutic agent for this, sorafenib (Nexavar, BAY43-9006), is an oral multikinase inhibitor that blocks tumor cell proliferation and angiogenesis, and induces tumor cell apoptosis by inhibiting serine/threonine kinases (c-RAF and mutant and wild-type BRAF) as well as the receptor tyrosine kinases vascular endothelial growth factor receptor 2 and 3 (VEGFR2 and VEGFR3), platelet- derived growth factor receptor , FLT3, and c-KIT. Sorafenib is currently used in clinics to treat patients with advanced renal cell carcinoma, hepatocellular carcinoma, and thyroid cancer. These findings provide a molecular evidence base for the use of chemoradiation to treat colon cancer, and in vivo modeling should be used to further assess its suitability for clinical applications.

  20. Radiosensitivity of human lymphocytes and thymocytes

    International Nuclear Information System (INIS)

    Kwan, D.K.; Norman, A.

    1977-01-01

    The in vitro survival of human peripheral blood lymphocytes and thymocytes was measured 4 days following graded doses of γ radiation. Results indicate considerable heterogeneity among lymphocyte subpopulations with respect to radiosensitivity. Total T lymphocytes were characterized by rosette formation with neuraminidase-treated sheep red blood cells (nSRBC); early T (T/sub E/) cells, by early rosettes; and B cells, by their inability to form nSRBC rosettes. Late T (T/sub L/) cells were defined as T -- T/sub E/. Survival curves of T, T/sub E/, and B cells are biphasic. The radiosensitive and radioresistant components of T, T/sub E/, and B cells all have a D 0 of about 50 and 550 rad, respectively. B cells appeared to be slightly more radiosensitive than T cells. T/sub L/ cells and thymocytes, however, appeared to be homogeneous with respect to radiosensitivity, both having D 0 values of about 135 rad. The survival of T cells in mixed T and B cell cultures resembled that of separated T cells, suggesting that ionizing radiation has no significant effect on rosette formation. It also indicates that interactions of T and B cells do not significantly affect their radiation responses

  1. Increased radiosensitivity of a subpopulation ot T-lymphocyte progenitors from patients with Fanconi's anemia

    International Nuclear Information System (INIS)

    Knox, S.J.; Wilson, F.D.; Greenberg, B.R.; Shifrine, M.; Rosenblatt, L.S.; Reeves, J.D.; Misra, H.

    1981-01-01

    In vitro radiation survival of peripheral blood T lymphocytes was studied in 15 clinically normal adults and 4 patients with Fanconi's anemia. Tritiated thymidine incorporation in a whole blood lymphocyte stimulation test (LST) and a newly developed whole blood T-lymphocyte colony assay were used to measure lymphocyte blastogenesis and colony formation in response to phytohemagglutinin (PHA) or concanavalin-A (Con-A) stimulation. Lymphocyte colony formation was found to be consistently more sensitive than the LST for detection of low-level radiation effects using both normal cells and lymphocytes from Fanconi's anemia patients. Lymphocytes from patients with Fanconi's anemia were significantly more sensitive to in vitro x-irradiation than lymphocytes from clinically normal individuals as measured by their ability to divide when stimulated by PHA in the LST (patients, D37 . 198 R; normals, D37 . 309 R, p . 0.057) and colony formation assay (patients, D37 . 53 R; normals, D37 . 109 R, p . 0.016). No significant difference in the radiosensitivity of the Con-A response was observed between the two groups. The PHA-responsive T-lymphocyte subpopulation in Fanconi's anemia patients appears to be intrinsically defective. The nature of this defect, significance in the disease process, and relevancy of these findings to the establishment of radiation protection standards are discussed

  2. Can intrinsic human tissue radiosensitivity be correlated with late responding gene RNA expression in white blood cells using a 96 gene micro-array?

    International Nuclear Information System (INIS)

    Schmidt, D.; Streeter, O.; Dagliyan, G.; Hill, C.K.; Williams-Hill, D.M.

    2003-01-01

    Radiation is widely used in the treatment of cancers. It is generally believed there is a sigmoid relationship between radiation dose and probability of cure. There is also a sigmoid relationship between radiation dose and normal tissue response. Generally total radiation dose to a tumor is limited by normal tissue tolerance. It has been postulated that up to 70% of inter-individual differences in radiosensitivity may be due to genetic predisposition (Tureson I. Et al, IJROBP, 1996;36:1065). However, to date, clinicians have no way of estimating or predicting an individual's normal tissue response to radiation exposure. Thus the prescribed dose cannot be tailored to an individuals actual expected response but is an empirically derived compromise based on experience. Although a number of studies using cellular techniques have shown that human cell radiosensitivity can be measured, none of these can be performed quick enough to be used in the clinic. In this study we are looking at gene expression that occurs some 24 hours after an exposure compared to expression before any exposure in peripheral white blood cells from patients undergoing radiotherapy for various tumors. The patients will be followed for overt radiation sensitivity by standard criteria by clinicians in the Department. The main aims are: does RNA expression level in a 96 gene micro-array vary before and after radiation and do these changes in RNA expression correlate with the objective measurements of acute radiation response observed by the clinicians in the patients. The USC IRB recently approved the protocol and human consent for this study to enter 50 patients in the next 12 months using mostly head and neck and endometrial cancer patients where we can get a normal tissue sample to examine as well as the blood sample. We will present the rationale, protocol, methods and early results in detail

  3. TU-F-CAMPUS-T-03: Enhancing the Tumor Specific Radiosensitization Using Molecular Targeted Gold Nanorods

    International Nuclear Information System (INIS)

    Diagaradjane, P; Deorukhkar, A; Sankaranarayanapillai, M; Singh, P; Manohar, N; Tailor, R; Cho, S; Goodrich, G; Krishnan, S

    2015-01-01

    Purpose: Gold nanoparticle (GNP) mediated radiosensitization has gained significant attention in recent years. However, the widely used passive targeting strategy requires high concentration of GNPs to induce the desired therapeutic effect, thus dampening the enthusiasm for clinical translation. The purpose of this study is to utilize a molecular targeting strategy to minimize the concentration of GNPs injected while simultaneously enhancing the tumor specific radiosensitization for an improved therapeutic outcome. Methods: Cetuximab (antibody specific to the epidermal growth factor receptor that is over-expressed in tumors) conjugated gold nanorods (cGNRs) was used for the tumor targeting. The binding affinity, internalization, and in vitro radiosensitization were evaluated using dark field microscopy, transmission electron microscopy, and clonogenic cell survival assay, respectively. In vivo biodistribution in tumor (HCT116-colorectal cancer cells) bearing mice were quantified using inductively coupled plasma mass spectrometry. In vivo radiosensitization potential was tested using 250-kVp x-rays and clinically relevant 6-MV radiation beams. Results: cGNRs displayed excellent cell-surface binding and internalization (∼31,000 vs 12,000/cell) when compared to unconjugated GNRs (pGNRs). In vitro, the dose enhancement factor at 10% survival (DEF10) was estimated as 1.06 and 1.17, respectively for both 250-kVp and 6-MV beams. In vivo biodistribution analysis revealed enhanced uptake of cGNRs in tumor (1.3 µg/g of tumor tissue), which is ∼1000-fold less than the reported values using passive targeting strategy. Nonetheless, significant radiosensitization was observed in vivo with cGNRs when compared to pGNRs, when irradiated with 250-kVp (tumor volume doubling time 35 days vs 25 days; p=0.002) and 6 MV (17 days vs 13 days; p=0.0052) beams. Conclusion: The enhanced radiosensitization effect observed with very low intratumoral concentrations of gold and megavoltage x

  4. TU-F-CAMPUS-T-03: Enhancing the Tumor Specific Radiosensitization Using Molecular Targeted Gold Nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Diagaradjane, P [M.D. Anderson Cancer Center, Houston, TX (United States); Deorukhkar, A; Sankaranarayanapillai, M; Singh, P [The UT MD Anderson Cancer Center, Houston, TX (United States); Manohar, N; Tailor, R; Cho, S [UT MD Anderson Cancer Center, Houston, TX (United States); Goodrich, G [Nanospectra Biosciences Inc, Houston, TX (United States); Krishnan, S [The University of Texas MD Anderson Cancer Center, Houston, TX (United States)

    2015-06-15

    Purpose: Gold nanoparticle (GNP) mediated radiosensitization has gained significant attention in recent years. However, the widely used passive targeting strategy requires high concentration of GNPs to induce the desired therapeutic effect, thus dampening the enthusiasm for clinical translation. The purpose of this study is to utilize a molecular targeting strategy to minimize the concentration of GNPs injected while simultaneously enhancing the tumor specific radiosensitization for an improved therapeutic outcome. Methods: Cetuximab (antibody specific to the epidermal growth factor receptor that is over-expressed in tumors) conjugated gold nanorods (cGNRs) was used for the tumor targeting. The binding affinity, internalization, and in vitro radiosensitization were evaluated using dark field microscopy, transmission electron microscopy, and clonogenic cell survival assay, respectively. In vivo biodistribution in tumor (HCT116-colorectal cancer cells) bearing mice were quantified using inductively coupled plasma mass spectrometry. In vivo radiosensitization potential was tested using 250-kVp x-rays and clinically relevant 6-MV radiation beams. Results: cGNRs displayed excellent cell-surface binding and internalization (∼31,000 vs 12,000/cell) when compared to unconjugated GNRs (pGNRs). In vitro, the dose enhancement factor at 10% survival (DEF10) was estimated as 1.06 and 1.17, respectively for both 250-kVp and 6-MV beams. In vivo biodistribution analysis revealed enhanced uptake of cGNRs in tumor (1.3 µg/g of tumor tissue), which is ∼1000-fold less than the reported values using passive targeting strategy. Nonetheless, significant radiosensitization was observed in vivo with cGNRs when compared to pGNRs, when irradiated with 250-kVp (tumor volume doubling time 35 days vs 25 days; p=0.002) and 6 MV (17 days vs 13 days; p=0.0052) beams. Conclusion: The enhanced radiosensitization effect observed with very low intratumoral concentrations of gold and megavoltage x

  5. Increased radiosensitivity of a subpopulation of T-lymphocyte progenitors from patients with Fanconi's anemia

    International Nuclear Information System (INIS)

    Knox, S.J.; Wilson, F.D.; Greenberg, B.R.; Shifrine, M.; Rosenblatt, L.S.; Reeves, J.D.; Misra, H.

    1981-01-01

    In vitro radiation survival of peripheral blood T lymphocytes was studied in 15 clinically normal adults and 4 patients with Fanconi's anemia. Tritiated thymidine incorporation in a whole blood lymphocyte stimulation test (LST) and a newly developed whole blood T-lymphocyte colony assay were used to measure lymphocyte blastogenesis and colony formation in response to phytohemagglutinin (PHA) or concanavalin-A (Con-A) stimulation. Lymphocyte colony formation was found to be consistently more sensitive than the LST for detection of low-level radiation effects using both normal cells and lymphocytes from Fanconi's anemia patients. Lymphocytes from patients with Fanconi's anemia were significantly more sensitive to in vitro x irradiation than lymphocytes from clinically normal individuals as measured by their ability to divide when stimulated by PHA in the LST and colony formation assay. No significant difference in the radiosensitivity of the Con-A response was observed between the two groups. The PHA-responsive T-lymphocyte subpopulation in Fanconi's anemia patients appears to be intrinsically defective. The nature of this defect, significance in the disease process, and relevancy of these findings to the establishment of radiation protection standards are discussed

  6. Hyperthermic radiosensitization : mode of action and clinical relevance

    NARCIS (Netherlands)

    Kampinga, HH; Dikomey, E

    Purpose: To provide an update on the recent knowledge about the molecular mechanisms of thermal radiosensitization and its possible relevance to thermoradiotherapy. Summary: Hyperthermia is probably the most potent cellular radiosensitizer known to date. Heat interacts with radiation and potentiates

  7. Proliferative activity of stomach cancer and assessment of individual radiosensitivity

    International Nuclear Information System (INIS)

    Chissov, V.I.; Sergeeva, N.S.; Dar'yalova, S.L.; Petrov, A.N.; Repina, A.G.; Belous, T.A.; Pelevina, I.I.

    1991-01-01

    An indirect immunofluorescent method with polyclonal antibodies to thymidine was used to assess the proliferative activity (PA-percent of cells in the S-phase of the cell cycle) of 79 stomach tumors from primary cancer patients. Stomach cancer PA was shown to vary from 0.1 to 69.7%. Stomach cancer PA did not depend either on a tumor size or a degree of the involvement of regional lymph nodes. The mean PA of well-differentiated adenocarcinoma was slightly lower (14.9±4.7%) than that of low differentiated ones. Of 79 patients a tumor process was interpreted as a resectable one in 62. They were given preoperative irradiation at a total focal dose of 36 Gy followed by operation. It was shown that tumor radioresistance could be predicted in unchanged PA indices of their increase at the beginning of a course of irradiation with the probability of 95%

  8. Inhibition of checkpoint kinase 1 sensitizes lung cancer brain metastases to radiotherapy

    International Nuclear Information System (INIS)

    Yang, Heekyoung; Yoon, Su Jin; Jin, Juyoun; Choi, Seung Ho; Seol, Ho Jun; Lee, Jung-Il

    2011-01-01

    Research highlights: → The most important therapeutic tool in brain metastasis is radiation therapy. → Radiosensitivity of cancer cells was enhanced with treatment of Chk1 inhibitor. → Depletion of Chk1 in cancer cells showed an enhancement of sensitivity to radiation. → Chk1 can be a good target for enhancement of radiosensitivity. -- Abstract: The most important therapeutic tool in brain metastasis is radiation therapy. However, resistance to radiation is a possible cause of recurrence or treatment failure. Recently, signal pathways about DNA damage checkpoints after irradiation have been noticed. We investigated the radiosensitivity can be enhanced with treatment of Chk1 inhibitor, AZD7762 in lung cancer cell lines and xenograft models of lung cancer brain metastasis. Clonogenic survival assays showed enhancement of radiosensitivity with AZD7762 after irradiation of various doses. AZD7762 increased ATR/ATM-mediated Chk1 phosphorylation and stabilized Cdc25A, suppressed cyclin A expression in lung cancer cell lines. In xenograft models of lung cancer (PC14PE6) brain metastasis, AZD7762 significantly prolonged the median survival time in response to radiation. Depletion of Chk1 using shRNA also showed an enhancement of sensitivity to radiation in PC14PE6 cells. The results of this study support that Chk1 can be a good target for enhancement of radiosensitivity.

  9. Studies on Drosophila radiosensitivity strains

    International Nuclear Information System (INIS)

    Varentsova, E.R.; Sharygin, V.I.; Khromykh, Yu.U.

    1985-01-01

    Fertility of radiosensitive mutant drosophila female strain rad (2) 201 61 after irradiation and frequency of dominant lethal mutations (DLM), induced by γ-radiation for 0-5 h and 5-7 days, are investigated. It is shown, that oocytes of the mutant strain are more radiosensitive as compared with cells of mongrel flies as to criterion of DLM appearance over the period of maturing. Early oocytes of stages 2-7 are the most sensitive, i.e. at the stages, corresponding to the manifestation of previously established recombination-defective properties of mutations rad (2) 201 61 . It is also sown, that doses of γ-rays, exceeding 10 Gy produce a strong sterilizing effect on mutant females due to destruction and resorption of egg chambers, irradiated at the stages of previtellogenetic growth of oocytes. In females, carrying mutation of radiosensitivity there is no direct correlation betwen sensitivity of oocytes proper to DLM induction and sensitivity of egg folleicles to resorbing effect of γ-rays. The ways of possible involvement of mutant locus studied into genetic processes in various specialized cells of drosophila

  10. Radiosensitivity of primary cultured fish cells with different ploidy

    International Nuclear Information System (INIS)

    Mitani, Hiroshi; Egami, Nobuo; Kobayashi, Hiromu.

    1986-01-01

    The radiosensitivity of primary cultured goldfish cells (Carassius auratus) was investigated by colony formation assay. The radiosensitivity of cells from two varieties of goldfish, which show different sensitivity to lethal effect of ionizing radiation in vivo, was almost identical. Primary cultured cells from diploid, triploid and tetraploid fish retained their DNA content as measured by microfluorometry, and the nuclear size increases as ploidy increases. However, radiosensitivity was not related to ploidy. (author)

  11. Causation of cancer by ionizing radiation and genomic instability

    International Nuclear Information System (INIS)

    Streffer, Christian

    2013-01-01

    The causation of cancer by ionizing radiation has been shown in many epidemiological (with exposed humans) as well as experimental studies with mammals especially mice but also rats, dogs and monkeys. Risk values have been determined in medium radiation dose ranges (∼100 to 2,000 mSv). However, in the low dose range (<100 mSv) the situation is unclear and unsolved up to now. A better knowledge of the mechanisms for the development of cancer in humans over decades after low to medium radiation exposures is necessary for the understanding of the open questions. An increase of chromosomal aberrations and other genetic changes have been frequently observed directly after radiation exposures in many cell systems including human cells. However, in 1989 it was found that an increase of genomic instability occurred after irradiation of mouse zygotes in the fibroblasts of the neonates developing from the irradiated zygotes. That means genomic instability developed many cell generations later in cells which never had been exposed to various qualities of ionizing radiations in vivo and any treatment and secondary cancers developed in photon irradiated M.Hodgkin patients preferentially in those patients who showed a comparatively high genomic instability in their lymphocytes. Since several decades it has been experienced that certain cancer patients show an extremely high radio-sensitivity. This clinical observation has been confirmed by experimental investigations with cells of such patients. It has been proven that this increased radio-sensitivity is due to genetic mutations. A number of syndromes could be defined on such a genetic basis like ataxia telangiectasia, bloom's syndrome, fanconi anemia, retinoblasoma and others. In all these syndromes mutations occur in genes which are to regulation of the cell cycle or DNA repair (preferentially repair of DSBs). These patients with an increased radio-sensitivity frequently develop cancer - very often lymphoma - and they also

  12. Bevacizumab in the treatment of five patients with breast cancer and brain metastases: Japan Breast Cancer Research Network-07 trial

    Directory of Open Access Journals (Sweden)

    Yamamoto D

    2012-09-01

    Full Text Available Daigo Yamamoto,1,3 Satoru Iwase,2 Yu Tsubota,1 Noriko Sueoka,1 Chizuko Yamamoto,3 Kaoru Kitamura,4 Hiroki Odagiri,5 Yoshinori Nagumo61Department of Surgery, Kansai Medical University, Hirakata, Osaka, 2Department of Palliative Medicine, University of Tokyo Hospital, Tokyo, 3Department of Internal Medicine, Seiko Hospital, Neyagawa, Osaka, 4Breast Unit, Nagumo Clinic, Fukuoka, 5Department of Surgery, Hirosaki National Hospital, Hirosaki, 6Breast Unit, Nagumo Clinic, Tokyo, JapanBackground: Brain metastases from breast cancer occur in 20%–40% of patients, and the frequency has increased over time. New radiosensitizers and cytotoxic or cytostatic agents, and innovative techniques of drug delivery are still under investigation.Methods: Five patients with brain metastases who did not respond to whole-brain radiotherapy and then received bevacizumab combined with paclitaxel were identified using our database of records between 2011 and 2012. The clinicopathological data and outcomes for these patients were then reviewed.Results: The median time to disease progression was 86 days. Of five patients, two (40% achieved a partial response, two had stable disease, and one had progressive disease. In addition, one patient with brain metastases had ptosis and diplopia due to metastases of the right extraocular muscles. However, not only the brain metastases, but also the ptosis and diplopia began to disappear after 1 month of treatment. The most common treatment-related adverse events (all grades were hypertension (60%, neuropathy (40%, and proteinuria (20%. No grade 3 toxicity was seen. No intracranial hemorrhage was observed.Conclusion: We present five patients with breast cancer and brain metastases, with benefits from systemic chemotherapy when combined with bevacizumab.Keywords: brain, bevacizumab, metastatic breast cancer

  13. DNA double-strand break repair of blood lymphocytes and normal tissues analysed in a preclinical mouse model: implications for radiosensitivity testing.

    Science.gov (United States)

    Rübe, Claudia E; Grudzenski, Saskia; Kühne, Martin; Dong, Xiaorong; Rief, Nicole; Löbrich, Markus; Rübe, Christian

    2008-10-15

    Radiotherapy is an effective cancer treatment, but a few patients suffer severe radiation toxicities in neighboring normal tissues. There is increasing evidence that the variable susceptibility to radiation toxicities is caused by the individual genetic predisposition, by subtle mutations, or polymorphisms in genes involved in cellular responses to ionizing radiation. Double-strand breaks (DSB) are the most deleterious form of radiation-induced DNA damage, and DSB repair deficiencies lead to pronounced radiosensitivity. Using a preclinical mouse model, the highly sensitive gammaH2AX-foci approach was tested to verify even subtle, genetically determined DSB repair deficiencies known to be associated with increased normal tissue radiosensitivity. By enumerating gammaH2AX-foci in blood lymphocytes and normal tissues (brain, lung, heart, and intestine), the induction and repair of DSBs after irradiation with therapeutic doses (0.1-2 Gy) was investigated in repair-proficient and repair-deficient mouse strains in vivo and blood samples irradiated ex vivo. gammaH2AX-foci analysis allowed to verify the different DSB repair deficiencies; even slight impairments caused by single polymorphisms were detected similarly in both blood lymphocytes and solid tissues, indicating that DSB repair measured in lymphocytes is valid for different and complex organs. Moreover, gammaH2AX-foci analysis of blood samples irradiated ex vivo was found to reflect repair kinetics measured in vivo and, thus, give reliable information about the individual DSB repair capacity. gammaH2AX analysis of blood and tissue samples allows to detect even minor genetically defined DSB repair deficiencies, affecting normal tissue radiosensitivity. Future studies will have to evaluate the clinical potential to identify patients more susceptible to radiation toxicities before radiotherapy.

  14. Radiosensitization of normoxic and hypoxic h1339 lung tumor cells by heat shock protein 90 inhibition is independent of hypoxia inducible factor-1α.

    Science.gov (United States)

    Schilling, Daniela; Bayer, Christine; Li, Wei; Molls, Michael; Vaupel, Peter; Multhoff, Gabriele

    2012-01-01

    Ionizing irradiation is a commonly accepted treatment modality for lung cancer patients. However, the clinical outcome is hampered by normal tissue toxicity and tumor hypoxia. Since tumors often have higher levels of active heat shock protein 90 (Hsp90) than normal tissues, targeting of Hsp90 might provide a promising strategy to sensitize tumors towards irradiation. Hsp90 client proteins include oncogenic signaling proteins, cell cycle activators, growth factor receptors and hypoxia inducible factor-1α (HIF-1α). Overexpression of HIF-1α is assumed to promote malignant transformation and tumor progression and thus might reduce the accessibility to radiotherapy. Herein, we describe the effects of the novel Hsp90 inhibitor NVP-AUY922 and 17-allylamino-17-demethoxygeldanamycin (17-AAG), as a control, on HIF-1α levels and radiosensitivity of lung carcinoma cells under normoxic and hypoxic conditions. NVP-AUY922 exhibited a similar biological activity to that of 17-AAG, but at only 1/10 of the dose. As expected, both inhibitors reduced basal and hypoxia-induced HIF-1α levels in EPLC-272H lung carcinoma cells. However, despite a down-regulation of HIF-1α upon Hsp90 inhibition, sensitivity towards irradiation remained unaltered in EPLC-272H cells under normoxic and hypoxic conditions. In contrast, treatment of H1339 lung carcinoma cells with NVP-AUY922 and 17-AAG resulted in a significant up-regulation of their initially high HIF-1α levels and a concomitant increase in radiosensitivity. In summary, our data show a HIF-1α-independent radiosensitization of normoxic and hypoxic H1339 lung cancer cells by Hsp90 inhibition.

  15. Role of novel anticancer drug Roscovitine on enhancing radiosensitivity in carcinoma cell lines

    International Nuclear Information System (INIS)

    Mohamed, H.M.S.

    2009-01-01

    The present study was conducted to evaluate the radiosensitization effect of Roscovitine (cyclin dependent kinase inhibitor) in carcinoma cell lines. Three cell lines are used (HepG2 liver carcinoma cell line, U251 brain carcinoma cell line, H460 Lung carcinoma cell line) in this study .cells were treated with Roscovitine in different concentrations ranging from 0.1μM to 100 μM before exposure to radiation doses ranging from 0.5 Gy to 20 Gy according to each experiment. The cell viability by MTT assay, The cell cycle analysis by flow cytometry and DNA fragmentation repair mechanism by diphenylamine were measured after Roscovitine treatment with or without radiation to explore the sensitization effect of Roscovitine. The present study conclude that Roscovitine a good candidate as radiosensitizer for modifying the ionizing radiation (IR) response in cancer cells, beside its cyclin dependent kinase inhibitor function, roscovitine can generate DNA Double strand Breaks and cooperate to enhance IR induce DNA damages . Roscovitine is currently in clinical trials, although our findings suggest that the combination of Roscovitine with IR appears to be a very promising especially for liver, brain and lung cancer treatment, further investigation is needed to evaluate the therapeutic index before tested in clinical trial

  16. Role of novel anticancer drug Roscovitine on enhancing radiosensitivity in carcinoma cell lines

    International Nuclear Information System (INIS)

    Noaman, E.; Sayed, H.M.; Medhat, A.M.; Morcos, N.Y.S.

    2010-01-01

    The present study was conducted to evaluate the radiosensitization effect of Roscovitine (cyclin dependent kinase inhibitor) in carcinoma cell lines. Three cell lines are used liver carcinoma cell line (HepG2), brain carcinoma cell line (U251), Lung carcinoma cell line (H460) in this study cells were treated with Roscovitine in different concentrations ranging from 0.1 ?M to 100 ?M before exposure to radiation doses ranging from 0.5 Gy to 20 Gy according to each experiment. The cell viability by MTT assay, the cell cycle analysis by flow cytometry and DNA fragmentation repair mechanism by diphenylamine were measured after Roscovitine treatment with or without radiation exposure to explore the sensitization effect of Roscovitine. The present study conclude that Roscovitine a good candidate as radiosensitizer for modifying the ionizing radiation (IR) response in cancer cells, beside its cyclin dependent kinase inhibitor function, Roscovitine can generate DNA Double strand Breaks and cooperate to enhance IR induce DNA damages. Roscovitine is currently in clinical trials, although our findings suggest that the combination of Roscovitine with IR appears to be a very promising especially for liver, brain and lung cancer treatment, further investigation is needed to evaluate the therapeutic index before tested in clinical trials

  17. Tumour-specific radiosensitizers for radiation therapy

    International Nuclear Information System (INIS)

    Denekamp, J.

    1977-01-01

    Recently Adams and coworkers at the Gray Laboratory have developed a new class of radiosensitizers which act specifically on hypoxic cells by abolishing the protection afforded by low oxygen concentrations. Since most experimental tumours contain a high proportion of oxygen-deprived cells, and most normal tissues are well oxygenated, these drugs are tumour specific radiosensitizers. Based on the hypothesis that sensitization increases with increasing electron affinity, the two nitroimidazoles, metronidazole (Flagyl) and Ro-07/0582 were identified as potent radiosensitizers with low toxicity. These drugs are effective only in the absence of oxygen, and only if the drug is present at the time of irradiation. The degree of sensitization increases with drug concentration rapidly over the range 0.1 to 1.0mg/g body weight for Ro-07-0582, and more gradually for Flagyl. Tumour studies have been performed on at least 12 different experimental tumours, using a variety of end points. Significant sensitization has been observed in every tumour studied, often corresponding to a dose reduction factor of 2.0 for high but non-toxic drug doses. Fractionated studies have also been performed on a few tumour lines. In most cases a useful therapeutic advantage was observed, although the sensitization was smaller. Ro-07-0582 used with X-rays gives a therapeutic gain comparable with that from cyclotron-produced fast neutrons. Neutrons used together with Ro-07-0582 are even more effective. In addition to the radiosensitization there is a specific cytotoxicity to hypoxic cells after prolonged exposure to Ro-07-0582. This cytotoxicity can be greatly enhanced in vitro by moderate hyperthermia. Flagyl and Ro-07-0582 have been used clinically as radiosensitizers, with promising early results. The clinical application is limited to certain dose fractionation patterns because of neurotoxicity. (author)

  18. Optimal energy for cell radiosensitivity enhancement by gold nanoparticles using synchrotron-based monoenergetic photon beams.

    Science.gov (United States)

    Rahman, Wan Nordiana; Corde, Stéphanie; Yagi, Naoto; Abdul Aziz, Siti Aishah; Annabell, Nathan; Geso, Moshi

    2014-01-01

    Gold nanoparticles have been shown to enhance radiation doses delivered to biological targets due to the high absorption coefficient of gold atoms, stemming from their high atomic number (Z) and physical density. These properties significantly increase the likelihood of photoelectric effects and Compton scattering interactions. Gold nanoparticles are a novel radiosensitizing agent that can potentially be used to increase the effectiveness of current radiation therapy techniques and improve the diagnosis and treatment of cancer. However, the optimum radiosensitization effect of gold nanoparticles is strongly dependent on photon energy, which theoretically is predicted to occur in the kilovoltage range of energy. In this research, synchrotron-generated monoenergetic X-rays in the 30-100 keV range were used to investigate the energy dependence of radiosensitization by gold nanoparticles and also to determine the photon energy that produces optimum effects. This investigation was conducted using cells in culture to measure dose enhancement. Bovine aortic endothelial cells with and without gold nanoparticles were irradiated with X-rays at energies of 30, 40, 50, 60, 70, 81, and 100 keV. Trypan blue exclusion assays were performed after irradiation to determine cell viability. Cell radiosensitivity enhancement was indicated by the dose enhancement factor which was found to be maximum at 40 keV with a value of 3.47. The dose enhancement factor obtained at other energy levels followed the same direction as the theoretical calculations based on the ratio of the mass energy absorption coefficients of gold and water. This experimental evidence shows that the radiosensitization effect of gold nanoparticles varies with photon energy as predicted from theoretical calculations. However, prediction based on theoretical assumptions is sometimes difficult due to the complexity of biological systems, so further study at the cellular level is required to fully characterize the effects

  19. Radiosensitivity of lymphocytes among Filipinos: final report

    International Nuclear Information System (INIS)

    Medina, F.I.S.; Gregorio, J.S.; Aguilar, C.P.; Poblete, E.E.

    1996-01-01

    This report is about the studies on the radiosensitivity of Filipino lymphocytes to radiation that can elucidate on the potential of blood chromosomes as biological dosimeters. The objective of this study is to determine the radiosensitivity of lymphocytes among Filipinos and to establish the radiation-induced chromosome anomaly standard curve in lymphocytes for radiological dosimetry. 47 refs., 9 figs., 1 tab

  20. Ionizing Radiation Activates AMP-Activated Kinase (AMPK): A Target for Radiosensitization of Human Cancer Cells

    International Nuclear Information System (INIS)

    Sanli, Toran; Rashid, Ayesha; Liu Caiqiong

    2010-01-01

    Purpose: Adenosine monophosphate (AMP)-activated kinase (AMPK) is a molecular energy sensor regulated by the tumor suppressor LKB1. Starvation and growth factors activate AMPK through the DNA damage sensor ataxia-telangiectasia mutated (ATM). We explored the regulation of AMPK by ionizing radiation (IR) and its role as a target for radiosensitization of human cancer cells. Methods and Materials: Lung, prostate, and breast cancer cells were treated with IR (2-8 Gy) after incubation with either ATM or AMPK inhibitors or the AMPK activator metformin. Then, cells were subjected to either lysis and immunoblotting, immunofluorescence microscopy, clonogenic survival assays, or cell cycle analysis. Results: IR induced a robust phosphorylation and activation of AMPK in all tumor cells, independent of LKB1. IR activated AMPK first in the nucleus, and this extended later into cytoplasm. The ATM inhibitor KU-55933 blocked IR activation of AMPK. AMPK inhibition with Compound C or anti-AMPK α subunit small interfering RNA (siRNA) blocked IR induction of the cell cycle regulators p53 and p21 waf/cip as well as the IR-induced G2/M arrest. Compound C caused resistance to IR, increasing the surviving fraction after 2 Gy, but the anti-diabetic drug metformin enhanced IR activation of AMPK and lowered the surviving fraction after 2 Gy further. Conclusions: We provide evidence that IR activates AMPK in human cancer cells in an LKB1-independent manner, leading to induction of p21 waf/cip and regulation of the cell cycle and survival. AMPK appears to (1) participate in an ATM-AMPK-p21 waf/cip pathway, (2) be involved in regulation of the IR-induced G2/M checkpoint, and (3) may be targeted by metformin to enhance IR responses.

  1. Combination Effect of Nimotuzumab with Radiation in Colorectal Cancer Cells

    International Nuclear Information System (INIS)

    Shin, Hye Kyung; Kim, Mi Sook; Jeong, Jae Hoon

    2010-01-01

    To investigate the radiosensitizing effect of the selective epidermal growth factor receptor (EGFR) inhibitor nimotuzumab in human colorectal cancer cell lines. Four human colorectal cancer cell lines, HCT-8, LoVo, WiDr, and HCT-116 were treated with nimotuzumab and/or radiation. The effects on cell proliferation, viability, and cell cycle progression were measured by MTT, clonogenic survival assay, flow cytometry, and Western blot. An immunoblot analysis revealed that EGFR phosphorylation was inhibited by nimotuzumab in colorectal cancer cell lines. Under these experimental conditions, pre-treatment with nimotuzumab increased radiosensitivity of colorectal cancer cell lines, except for cell line HCT-116. However, cell proliferation or cell cycle progression was not affected by the addition of nimotuzumab, irrespective of irradiation. Nimotuzumab enhanced the radiosensitivity of colorectal cancer cells in vitro by inhibiting EGFR-mediated cell survival signaling. This study provided a rationale for the clinical application of the selective EGFR inhibitor, nimotuzumab in combination with radiation in colorectal cancer cells.

  2. Heat shock protein 90 (Hsp90) chaperone complex. A molecular target for enhancement of thermosensitivity and radiosensitivity

    International Nuclear Information System (INIS)

    Akimoto, Tetsuo; Nonaka, Tetsuo; Kitamoto, Yoshizumi; Sakurai, Hideyuki

    2002-01-01

    Heat shock protein 90 (Hsp90) is a highly conserved heat shock protein in animal and plants, and exists abundantly in the cytoplasm in unstressed condition, accounting for 1-2% in cytoplasmic proteins. Main difference of Hsp90 from other Hsps are its substrate that Hsp90 binds to. These substrates include various signal transduction proteins, kinase, steroid receptors and transcription factors, therefore, Hsp90 plays a key role in maintaining cellular signal transduction networks. Many chaperoned proteins (client proteins) of Hsp90 are associated with cellular proliferation or malignant transformation, thus Hsp90 chaperone complex has been focused as targets for cancer therapy. Among the client proteins, there are several molecules that have been defined as targets or factors for determination or enhancement of radiosensitivity or thermosensitivity. Thus, it is easily speculated that Hsp90 chaperone complex inhibitors that disrupt association of Hsp90 and client protein in combination with radiation or/and heat has potential effect on enhancement of radiosensitivity or thermosensitivity. In this paper, possible mechanisms in enhancing radiosensitivity or thermosensitivity according to the client proteins will be summarized. (author)

  3. The merits of DNA content and cell kinetic parameters for the assessment of intrinsic cellular radiosensitivity to photon and high-LET neutron irradiation

    International Nuclear Information System (INIS)

    Theron, C.S.; Serafin, A.; Bohm, L.; Slabbert, J.P.

    1997-01-01

    Differences of the intrinsic cellular radiosensitivity between tumours make the selection of patients for specific radiation schedules very difficult. The reasons for these variations are still unclear, but are thought to be due to genomic and cellular characteristics. Radiosensitivities vary between cell cycle stages, with S-phase cells being most radioresistant and G2/M phase cells most radiosensitive. It is also well established that most tumour cells have an abnormal ploidy. DNA content and cellular proliferation kinetics therefore could influence the intrinsic radiosensitivity. This prompted us to assess the merits of these parameters as predictors of radiation response. (authors)

  4. The role of polymorphisms of genes repair pathway to the radiotoxicity in patients with cancer of the cervix; O papel dos polimorfismos de genes da via de reparo com a radiotoxidade em pacientes com cancer de colo uterino

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Ana Terra Silva

    2012-07-01

    Background: In Brazil, cervical cancer is the second most common among women. Radiation therapy is part of its interdisciplinary management, playing an important role in their loco regional control. The major challenge of modern medicine in radiotherapy is to develop predictive methods that can determine the level of radiosensitivity of the patient and the healthy surrounding tissue in order to individualize the prescribed radiation dose, to prevent severe side effects and promoting better local tumor control. This study evaluated the acute and chronic adverse effects on the skin, lower gastrointestinal tract and urinary tract of radiotherapy in 47 cervical cancer patients. Methods and Materials: Biological material was collected and DNA from peripheral blood was extracted of ali patients studied. The fragments of TP53 and ATM were amplified to be sequenced, to verify if there are any polymorphisms witch could be responsible to the radiosensitivity of the patients. Results and Discussion: In a univariate analysis, the variable age was strongly associated with a risk of acute toxicity skin (p=O,023). Patients that received a high dose of external beam radiation and patients who have undergone brachytherapy, showed a significantly higher incidence of chronic urinary tract toxicity (p=O,031) and (p=O,019), respectively. The exchange G>A in the position 5557 of the A TM gene was significantly associated with the risk of acute lower gastrointestinal tract (p=O,008). There wasn't association between the other TP53 polymorphisms analyzed and the frequency of side effects (p>O,05). Our data revealed that patients who evolved significant association presented death (p=O,019) with the increase of chronic skin radiossensitivity. Conclusions: These observations corroborate the importance of investigating the genetic profile to predict adverse side effects in cervical cancer patients undergoing radiotherapy. These genes have an important role in DNA repair pathways and

  5. Radiosensitizing effect of RHOB protein in melanoma cells

    International Nuclear Information System (INIS)

    Notcovich, C.; Grissi, C.; Sánchez Crespo, R.; Delgado, D.C.; Molinari, B.; Ibañez, I.L.; Durán, H.

    2015-01-01

    Melanoma cells are highly resistant to chemo or radiotherapy. DNA damage agents such as ionizing radiation induce apoptosis involving RhoB protein. In a great variety of tumors the levels of this protein decrease along tumor progression. RhoB is considered a tumor suppressor gene due to its antiproliferative and proapoptotic effect. Considering the aforementioned, the aim of this study was to characterize the radiobiological response of different human melanoma cell lines, and to evaluate the possible correlation between RhoB expression and radiosensitivity. The human melanoma cell lines A375, MELJ and SB2 were gamma-irradiated ( 137 Cs). Survival curves were obtained by clonogenic assay and fitted to the Linear-Quadratic (LQ) model. Radiosensitivity was evaluated by surviving fraction at 2 Gy (SF2). Results showed that MELJ was significantly more radioresistant (SF2=0.71) than A375 and SB2 (0.29 and 0.21 respectively. Expression levels of RhoB, evaluated by western blot, increased in all lines vs. non-irradiated control. SB2, the most radiosensitive cells, showed a greater induction (p<0.05) of RhoB. Finally, to study whether RhoB has a radiosensitizing effect, these cell lines were stably transfected with a wild type RhoB construction, a constitutively active RhoB mutant V14, or with the empty plasmid as control. For all cell lines higher expression level of this protein was found in RhoB or V14 transfected cells (p<0.05). Sensitization was evaluated by SF2. Significant radiosensitization was demonstrated in clones derived from A375 and SB2 ((p<0.05), while for MELJ cells, radio-sensitization was only found in clones overexpressing V14. In conclusion, the increase of RhoB in melanoma cell lines, either by radiation or transfection has a radiosensitizing effect. Thus, we propose RhoB modulation as a potential therapeutic tool to improve the radiation response of radioresistant melanoma. (authors)

  6. Radiosensitivity related to neuroendocrine and endodermal differentation in lung carcinoma lines

    International Nuclear Information System (INIS)

    Duchesne, G.; Casoni, A.; Pera, M.

    1988-01-01

    A panel of human lung carcinoma lines was studied with respect to hormone production and intermediate filament expression to distinguish between endodermal and neuroendocrine differentation. An index of the degree of neuroendocrine differentiation of each line was derived from the presence or absence of hormone production, cytokeratins, neurofilaments and an embryonic endodermal cell marker, which allowed identification of three groups showing high, intermediate or low neuroendocrine expression. This grouping correlated well with the in vitro radiosensitivity of the lines, those expressing pure neuroendocrine features being significantly more radiosensitive than those with an endodermal phenotype, with the intermediate group having intermediate sensitivity. Use of such an index might predict those patients likely to benefit from the use of radiotherapy in their management. 30 refs.; 3 figs.; 3 tabs

  7. Evaluating Tumor Response of Non-Small Cell Lung Cancer Patients With {sup 18}F-Fludeoxyglucose Positron Emission Tomography: Potential for Treatment Individualization

    Energy Technology Data Exchange (ETDEWEB)

    Toma-Dasu, Iuliana, E-mail: Iuliana.Livia.Dasu@ki.se [Medical Radiation Physics, Stockholm University and Karolinska Institutet, Stockholm (Sweden); Uhrdin, Johan [RaySearch Laboratories AB, Stockholm (Sweden); Lazzeroni, Marta [Medical Radiation Physics, Karolinska Institutet, Stockholm (Sweden); Carvalho, Sara; Elmpt, Wouter van; Lambin, Philippe [Department of Radiation Oncology, GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht (Netherlands); Dasu, Alexandru [Department of Radiation Physics and Department of Medical and Health Sciences, Linköping University, Linköping (Sweden)

    2015-02-01

    Objective: To assess early tumor responsiveness and the corresponding effective radiosensitivity for individual patients with non-small cell lung cancer (NSCLC) based on 2 successive {sup 18}F-fludeoxyglucose positron emission tomography (FDG-PET) scans. Methods and Materials: Twenty-six NSCLC patients treated in Maastricht were included in the study. Fifteen patients underwent sequential chemoradiation therapy, and 11 patients received concomitant chemoradiation therapy. All patients were imaged with FDG before the start and during the second week of radiation therapy. The sequential images were analyzed in relation to the dose delivered until the second image. An operational quantity, effective radiosensitivity, α{sub eff}, was determined at the voxel level. Correlations were sought between the average α{sub eff} or the fraction of negative α{sub eff} values and the overall survival at 2 years. Separate analyses were performed for the primary gross target volume (GTV), the lymph node GTV, and the clinical target volumes (CTVs). Results: Patients receiving sequential treatment could be divided into responders and nonresponders, using a threshold for the average α{sub eff} of 0.003 Gy{sup −1} in the primary GTV, with a sensitivity of 75% and a specificity of 100% (P<.0001). Choosing the fraction of negative α{sub eff} as a criterion, the threshold 0.3 also had a sensitivity of 75% and a specificity of 100% (P<.0001). Good prognostic potential was maintained for patients receiving concurrent chemotherapy. For lymph node GTV, the correlation had low statistical significance. A cross-validation analysis confirmed the potential of the method. Conclusions: Evaluation of the early response in NSCLC patients showed that it is feasible to determine a threshold value for effective radiosensitivity corresponding to good response. It also showed that a threshold value for the fraction of negative α{sub eff} could also be correlated with poor response. The proposed

  8. Pharmacological Inhibition of the Protein Kinase MRK/ZAK Radiosensitizes Medulloblastoma.

    Science.gov (United States)

    Markowitz, Daniel; Powell, Caitlin; Tran, Nhan L; Berens, Michael E; Ryken, Timothy C; Vanan, Magimairajan; Rosen, Lisa; He, Mingzu; Sun, Shan; Symons, Marc; Al-Abed, Yousef; Ruggieri, Rosamaria

    2016-08-01

    Medulloblastoma is a cerebellar tumor and the most common pediatric brain malignancy. Radiotherapy is part of the standard care for this tumor, but its effectiveness is accompanied by significant neurocognitive sequelae due to the deleterious effects of radiation on the developing brain. We have previously shown that the protein kinase MRK/ZAK protects tumor cells from radiation-induced cell death by regulating cell-cycle arrest after ionizing radiation. Here, we show that siRNA-mediated MRK depletion sensitizes medulloblastoma primary cells to radiation. We have, therefore, designed and tested a specific small molecule inhibitor of MRK, M443, which binds to MRK in an irreversible fashion and inhibits its activity. We found that M443 strongly radiosensitizes UW228 medulloblastoma cells as well as UI226 patient-derived primary cells, whereas it does not affect the response to radiation of normal brain cells. M443 also inhibits radiation-induced activation of both p38 and Chk2, two proteins that act downstream of MRK and are involved in DNA damage-induced cell-cycle arrest. Importantly, in an animal model of medulloblastoma that employs orthotopic implantation of primary patient-derived UI226 cells in nude mice, M443 in combination with radiation achieved a synergistic increase in survival. We hypothesize that combining radiotherapy with M443 will allow us to lower the radiation dose while maintaining therapeutic efficacy, thereby minimizing radiation-induced side effects. Mol Cancer Ther; 15(8); 1799-808. ©2016 AACR. ©2016 American Association for Cancer Research.

  9. Inhibiting DNA-PKCS radiosensitizes human osteosarcoma cells

    International Nuclear Information System (INIS)

    Mamo, Tewodros; Mladek, Ann C.; Shogren, Kris L.; Gustafson, Carl; Gupta, Shiv K.; Riester, Scott M.; Maran, Avudaiappan; Galindo, Mario; Wijnen, Andre J. van; Sarkaria, Jann N.; Yaszemski, Michael J.

    2017-01-01

    Osteosarcoma survival rate has not improved over the past three decades, and the debilitating side effects of the surgical treatment suggest the need for alternative local control approaches. Radiotherapy is largely ineffective in osteosarcoma, indicating a potential role for radiosensitizers. Blocking DNA repair, particularly by inhibiting the catalytic subunit of DNA-dependent protein kinase (DNA-PK CS ), is an attractive option for the radiosensitization of osteosarcoma. In this study, the expression of DNA-PK CS in osteosarcoma tissue specimens and cell lines was examined. Moreover, the small molecule DNA-PK CS inhibitor, KU60648, was investigated as a radiosensitizing strategy for osteosarcoma cells in vitro. DNA-PK CS was consistently expressed in the osteosarcoma tissue specimens and cell lines studied. Additionally, KU60648 effectively sensitized two of those osteosarcoma cell lines (143B cells by 1.5-fold and U2OS cells by 2.5-fold). KU60648 co-treatment also altered cell cycle distribution and enhanced DNA damage. Cell accumulation at the G2/M transition point increased by 55% and 45%, while the percentage of cells with >20 γH2AX foci were enhanced by 59% and 107% for 143B and U2OS cells, respectively. These results indicate that the DNA-PK CS inhibitor, KU60648, is a promising radiosensitizing agent for osteosarcoma. - Highlights: • DNA-PKcs is consistently expressed in human osteosarcoma tissue and cell lines. • The DNA-PKcs inhibitor, KU60648, effectively radiosensitizes osteosarcoma cells. • Combining KU60648 with radiation increases G2/M accumulation and DNA damage.

  10. Age-dependent radiosensitivity of mouse oocytes

    International Nuclear Information System (INIS)

    Koehler, C.

    1976-01-01

    It has been shown that there are three distinct phases of radiosensitivity in oocytes of prepubertal mice: a period of rapidly increasing sensitivity between 0 and 4 days of age; a period of consistent, high sensitivity between 5 and 18 days of age; and a period of decreasing sensitivity from 19 to at least 21 days of age. Two distinct phases have been demonstrated for the rate of population decline of the oocytes of primary follicles: an initial period of rapid loss from 0 to 4 days of age; and a period of much slower loss from 5 through 23 days of age. Correlations have been drawn between the first two phases of radiosensitivity and morphological changes in the oocyte, and between the third phase of radiosensitivity and endocrinological changes in the maturing animal. The reaction of oocytes to radiation has been separated into two categories: immediate death (within 24 hours); and delayed death (over the entire lifespan of the animal)

  11. Misonidazole as a radiosensitizer in the radiotherapy of glioblastomas and oesophageal cancer. Pharmacokinetic and clinical studies

    International Nuclear Information System (INIS)

    Tamulevicius, P.; Streffer, C.; Bamberg, M.; Scherer, E.

    1981-01-01

    Since May 1978 the hypoxic-cell radiosensitizer, misonidazole (MIS), has been under clinical investigation in a phase III trial with multiple doses of the drug in 11 patients with brain tumours (seven glioblastomas, four recurrent brain tumours) and three patients with oesophageal carcinoma. The doses of MIS administered were usually well tolerated but the principal toxicities observed were peripheral neuropathy as well as nausea and vomiting in the glioblastoma patients. The neuropathy was completely reversible. The incidence of neuropathy was not related to the pharmacological parameters of plasma level or half-life. Pharmacological assessment by high-pressure liquid chromatography included assays of plasma, urine and cerebrospinal fluid. The demethylated product, Ro-05-9963, was detected as the major metabolite. Peak plasma levels were obtained one to four hours after administration of MIS, with a half-life of five to ten hours. Cerebrospinal fluid levels of MIS correlated well with those of the plasma. MIS was mainly excreted as the demethylated metabolite, but less than 40% of the given dose could be recovered. The results obtained suggest that the present MIS dosage for glioblastoma patients results in a low plasma level with no observable therapeutic effect. (author)

  12. Contributions concerning radiosensitivity proffered by the basic sciences to clinical radiation therapy

    International Nuclear Information System (INIS)

    Caputo, A.

    1974-01-01

    Basic concepts of radiosensitivity are reviewed. Some topics discussed are: probability of lethal injury as a dose dependent function; mutations resulting from radiation damage to DNA; relation of cell radiosensitivity to chromosome volume; relation of molecular structure of DNA to relative radiosensitivity of the organism; repair replication of DNA following uv and x irradiation of Escherichia coli and mammalian cells; and relation of the cell cycle to radiosensitivity. (U.S.)

  13. Radiosensitivity of fingermillet genotypes

    Energy Technology Data Exchange (ETDEWEB)

    Raveendran, T S; Nagarajan, C; Appadurai, R; Prasad, M N; Sundaresan, N [Tamil Nadu Agricultural Univ., Coimbatore (India)

    1984-07-01

    Varietal differences in radiosensitivity were observed in a study involving 4 genotypes of fingermillet (Eleusine coracana (Linn.) Gaertn.) subjected to gamma-irradiation. Harder seeds were found to tolerate a higher dose of the mutagen.

  14. Improved Biochemical Outcomes With Statin Use in Patients With High-Risk Localized Prostate Cancer Treated With Radiotherapy

    International Nuclear Information System (INIS)

    Kollmeier, Marisa A.; Katz, Matthew S.; Mak, Kimberley; Yamada, Yoshiya; Feder, David J.; Zhang Zhigang; Jia Xiaoyu; Shi Weiji; Zelefsky, Michael J.

    2011-01-01

    Purpose: To investigate the association between 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) and biochemical and survival outcomes after high-dose radiotherapy (RT) for prostate cancer. Methods and Materials: A total of 1711 men with clinical stage T1-T3 prostate cancer were treated with conformal RT to a median dose of 81 Gy during 1995-2007. Preradiotherapy medication data were available for 1681 patients. Three hundred eighty-two patients (23%) were taking a statin medication at diagnosis and throughout RT. Nine hundred forty-seven patients received a short-course of neoadjuvant and concurrent androgen-deprivation therapy (ADT) with RT. The median follow-up was 5.9 years. Results: The 5- and 8-year PSA relapse-free survival (PRFS) rates for statin patients were 89% and 80%, compared with 83% and 74% for those not taking statins (p = 0.002). In a multivariate analysis, statin use (hazard ratio [HR] 0.69, p = 0.03), National Comprehensive Cancer Network (NCCN) low-risk group, and ADT use were associated with improved PRFS. Only high-risk patients in the statin group demonstrated improvement in PRFS (HR 0.52, p = 0.02). Across all groups, statin use was not associated with improved distant metastasis-free survival (DMFS) (p = 0.51). On multivariate analysis, lower NCCN risk group (p = 0.01) and ADT use (p = 0.005) predicted improved DMFS. Conclusions: Statin use during high-dose RT for clinically localized prostate cancer was associated with a significant improvement in PRFS in high-risk patients. These data suggest that statins have anticancer activity and possibly provide radiosensitization when used in conjunction with RT in the treatment of prostate cancer.

  15. Inhibition of STAT-3 results in radiosensitization of human squamous cell carcinoma

    International Nuclear Information System (INIS)

    Bonner, James A.; Trummell, Hoa Q.; Willey, Christopher D.; Plants, Brian A.; Raisch, Kevin P.

    2009-01-01

    Background: Signal transducer and activator of transcription-3 (STAT-3) is a downstream component of the Epidermal Growth Factor Receptor (EGFr) signaling process that may facilitate the resistance of tumor cells to conventional cancer treatments. Studies were performed to determine if inhibition of this downstream protein produces radiosensitization. Methods/Results: A431 cells (human squamous cell carcinoma cells with EGFr overexpression) were found to be sensitized to radiation after treatment with STAT-3 small interfering RNA (siRNA). Therefore, a short hairpin RNA (shRNA) against STAT-3 was designed and cloned into a pBABE vector system modified for shRNA expression. Following transfection, clone 2.1 was selected for further study as it showed a dramatic reduction of STAT-3 protein (and mRNA) when compared to A431 parental cells or a negative control shRNA cell line (transfected with STAT-3 shRNA with 2 base pairs mutated). A431 2.1 showed doubling times of 25-31 h as compared to 18-24 h for the parental cell line. The A431 shRNA knockdown STAT-3 cells A431 were more sensitive to radiation than A431 parental or negative STAT-3 control cells. Conclusion: A431 cells stably transfected with shRNA against STAT-3 resulted in enhanced radiosensitivity. Further work will be necessary to determine whether the inhibition of STAT-3 phosphorylation is a necessary step for the radiosensitization that is induced by the inhibition of EGFr.

  16. A review of human cell radiosensitivity in vitro

    International Nuclear Information System (INIS)

    Deschavanne, Patrick J.; Fertil, Bernard

    1996-01-01

    The survival curves of 694 human cell lines irradiated in exponentially growing phase in vitro were collected from the literature. Among them, 271 were derived from tumors, 423 were nontransformed fibroblasts and other normal cell strains from healthy people or people with some genetic disorders. Seventy-six different cell types are identified, and a specific radiosensitivity could be associated with each, using D-bar and surviving fraction at 2 Gy. Technical factors such as culture medium, feeder cells, and scoring method were found to affect intrinsic radiosensitivity. In particular, the cell type is not a discriminating factor when cells are studied in agar. Results obtained with cells irradiated in agar must be used cautiously, depending on how the cells were prepared for the experiments. The use of feeder cells narrows the range of radiosensitivity of human cells. For cells irradiated as monolayer, it was possible to build a scale of radiosensitivity according to cell type, ranging, in terms of D-bar from 0.6 Gy for the most sensitive cell lines to more than 4 Gy for the most resistant. Considering that, in most cases, we could estimate the variation of radiosensitivity within each cell type, our classification among cell types can be used by researchers to place their results in the context of the literature

  17. Alterations in gene expression profiles between radioresistant and radiosensitive cell lines

    International Nuclear Information System (INIS)

    Zhou Fuxiang; Zhou Yunfeng; Xie Conghua; Dai Jing; Cao Zhen; Yu Haijun; Liao Zhengkai; Luo Zhiguo

    2007-01-01

    Objective: To study the-difference of gene expressions by the contrastive model including the cells with same pathological origin and genetic background, but definitely different radioresponse, and to find the main molecular targets related to radiosensitivity. Methods: Human larynx squamous carcinoma cell, Hep -2 was irradiated with dose of 637 cGy repeatedly to establish a radioresistant daughter cell line. The radiobiology characteristics were obtained using clone forming assay. The difference of gene expression between parent and daughter cells was detected by cDNA microarray using two different arrays including 14000 genes respectively. Results: A radioresistant cell strain Hep-2R was isolated from its parental strain Hep-2 cell. The SF 2 , D 0 , α, β for Hep-2R cell line were 0.6798, 3.24, 0.2951 and 0.0363, respectively, while 0.4148, 2.06, 0.1074 and 0.0405 for Hep-2, respectively (for SF 2 , χ 2 =63.957, P<0.001). Compared with Hep-2 cells, the expressions of 41 genes were significantly altered in the radioresistant Hep-2R cells, including 22 genes up-regulated and 19 genes down-regulated, which were involved in DNA repair, regulation of the cell cycle, cell proliferation, cytoskeleton, protein synthesis, cellular metabolism and especially apoptosis which is responsible for the different radiosensitivity between these two larynx cancer cells. The telomere protection protein gene, POT1, was the mostly up-regulated by 3.348 times. Conclusions: There is difference of gene expression between the radioresistant contrastive models. POT1 gene may be the target of radiosensitization. (authors)

  18. Radiosensitization of mouse skin by oxygen and depletion of glutathione

    International Nuclear Information System (INIS)

    Stevens, Graham; Joiner, Michael; Joiner, Barbara; Johns, Helen; Denekamp, Juliana

    1995-01-01

    Purpose: To determine the oxygen enhancement ratio (OER) and shape of the oxygen sensitization curve of mouse foot skin, the extent to which glutathione (GSH) depletion radiosensitized skin, and the dependence of such sensitization on the ambient oxygen tension. Methods and Materials: The feet of WHT mice were irradiated with single doses of 240 kVp x-rays while mice were exposed to carbogen or gases with oxygen/nitrogen mixtures containing 8-100% O 2 . The anoxic response was obtained by occluding the blood supply to the leg of anesthetized mice with a tourniquet, surrounding the foot with nitrogen, and allowing the mice to breathe 10% O 2 . Further experiments were performed to assess the efficacy of this method to obtain an anoxic response. Radiosensitivity of skin was assessed using the acute skin-reaction assay. Glutathione levels were modified using two schedules of dl-buthionine sulphoximine (BSO) and diethylmaleate (DEM), which were considered to produce extensive and intermediate levels of GSH depletion in the skin of the foot during irradiation. Results: Carbogen caused the greatest radiosensitization of skin, with a reproducible enhancement of 2.2 relative to the anoxic response. The OER of 2.2 is lower than other reports for mouse skin. This may indicate that the extremes of oxygenation were not produced, although there was no direct evidence for this. When skin radiosensitivity was plotted against the logarithm of the oxygen tension in the ambient gas, a sigmoid curve with a K value of 17-21% O 2 in the ambient gas was obtained. Depletion of GSH caused minimal radiosensitization when skin was irradiated under anoxic or well-oxygenated conditions. Radiosensitization by GSH depletion was maximal at intermediate oxygen tensions of 10-21% O 2 in the ambient gas. Increasing the extent of GSH depletion led to increasing radiosensitization, with sensitization enhancement ratios of 1.2 and 1.1, respectively, for extensive and intermediate levels of GSH

  19. Targeted radiosensitization of cells expressing truncated DNA polymerase {beta}.

    NARCIS (Netherlands)

    Neijenhuis, S.; Verwijs-Janssen, M.; Broek, Bart van den; Begg, A.C.; Vens, C.

    2010-01-01

    Ionizing radiation (IR) is an effective anticancer treatment, although failures still occur. To improve radiotherapy, tumor-targeted strategies are needed to increase radiosensitivity of tumor cells, without influencing normal tissue radiosensitivity. Base excision repair (BER) and single-strand

  20. HLA‐G modulates the radiosensitivity of human neoplastic cells

    International Nuclear Information System (INIS)

    Michelin, Severino; Gallegos, Cristina; Baffa Trasci, Sofía; Dubner, Diana; Favier, B.; Carosella, E.D.

    2011-01-01

    Tumor cells show a very broad range of radiosensitivities. The differential radiosensitivity may depend on many factors, being the efficiency to recognize and/or repair the DNA lesion, and the cell cycle control mechanisms, the most important (Jeggo and Lavin, 2009; Kumala et al., 2003). Human leukocyte antigen‐G (HLA‐G) is a non‐classical HLA class I molecule involved in fetus protection form the maternal immune system, transplant tolerance, and viral and tumoral immune escape (Carosella et al., 2008). It has been determined that gamma radiation modulates HLA‐G expression at the plasma membrane of human melanoma cells. However, its role in tumoral radiosensitivity has not been demonstrated yet. The objective of this work was to determine if the radiosensitivity of human neoplastic cell lines cultured in vitro was mediated by HLA‐G expression. (authors)

  1. Radiosensitivity in Fanconi anaemia: application to the conditioning regimen for bone marrow transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Gluckman, E.; Devergie, A. (Hopital Saint-Louis, 75 - Paris (France)); Dutreix, J. (Institut Gustave Roussy, 94 - Villejuif (France))

    1983-07-01

    Fanconi anaemia, an autosomal recessive constitutional aplastic anaemia, seems to be related to a DNA repair mechanism defect. Bone marrow transplantation is the only treatment which can cure these patients. Previous attempts at BMT have shown an increased sensitivity to Cyclophosphamide used for the conditioning. Such a sensitivity has also been observed in vitro when Fanconi anaemia cells were incubated with alkylating agents. We have tested the in vivo radiosensitivity and cell repair after skin contact radiotherapy to calculate the irradiation dose which could be tolerated by FA patients. Eight patients have been tested and the results confirmed the suspected increased radiosensitivity in the majority of patients. Following these results, four patients were conditioned with low dose Cyclophosphamide (20 mg/kg) associated with 5 Grays thoraco-abdominal irradiation. All had a take and no major complication of the conditioning regimen. All are alive in good condition from day 51 to day 330 after transplant. Oesophagitis was one major unexpected complication. This study confirms the possibility of curing FA patients with BMT when the conditioning regimen is modified according to the pathophysiology of the disease.

  2. Radiosensitivity in Fanconi anaemia: application to the conditioning regimen for bone marrow transplantation

    International Nuclear Information System (INIS)

    Gluckman, E.; Devergie, A.; Dutreix, J.

    1983-01-01

    Fanconi anaemia, an autosomal recessive constitutional aplastic anaemia, seems to be related to a DNA repair mechanism defect. Bone marrow transplantation is the only treatment which can cure these patients. Previous attempts at BMT have shown an increased sensitivity to Cyclophosphamide used for the conditioning. Such a sensitivity has also been observed in vitro when Fanconi anaemia cells were incubated with alkylating agents. We have tested the in vivo radiosensitivity and cell repair after skin contact radiotherapy to calculate the irradiation dose which could be tolerated by FA patients. Eight patients have been tested and the results confirmed the suspected increased radiosensitivity in the majority of patients. Following these results, four patients were conditioned with low dose Cyclophosphamide (20 mg/kg) associated with 5 Grays thoraco-abdominal irradiation. all had a take and no major complication of the conditioning regimen. All are alive in good condition from day 51 to day 330 after transplant. Oesophagitis was one major unexpected complication. This study confirms the possibility of curing FA patients with BMT when the conditioning regimen is modified according to the pathophysiology of the disease. (author)

  3. Enhancement of the radiation-lethal effect of hypoxic cancer cells by some nitroheterocyclic compounds. Part of a coordinated programme on the improvement of radiotherapy of cancer using modifiers of radiosensitivity of cells

    International Nuclear Information System (INIS)

    Chiricuta, I.

    1981-12-01

    The possibilities to enhance the lethal effect of ionizing radiation on hypoxic cells by electron-affinic compounds have stimulated the investigations for finding new chemicals with radiobiological and pharmacological features as adequate as possible. On the other hand, the experimental studies and clinical trials had shown that the aerobic toxicity seems to be the major limiting factor in the use of large doses of radiosensitizers required to achieve significant therapeutic efficiency. The investigations in the present paper were attempted to join these two main directions of research and comprised the syntheses of new nitroheterocyclic compounds with potential radiosensitization properties and the knowledge of biochemical alterations involved in the producing of aerobic toxicity of radiosensitizers aiming to find practical solutions to enhance the efficiency of radiotherapy. Several newly synthesized compounds were tested for their radiosensitizing effect. The experiments carried out on hypoxic cells V 79 showed that only 1-(hydroxyethyl-2'-phosphate)-2-methyl-5-nitroimidazole, dipotassium salt displayed an enhancement ratio of 1.17 (at 8 mM), but lower than in case of parent compound, metronidazole (enhancement ratio = 1.53). It was shown that hypoxic cell radiosensitizers interfere with the cellular energy metabolism. These interferences were found dependent on the electron affinity of drugs. In addition, those radiosensitizers producing a decrease in oxygen consumption caused a supplementary oxygenation of both normal and tumour tissues. It is concluded that the improvement of therapeutic efficiency of radiosensitizers by reducing their aerobic toxicity might be achieved by diminishing their effects on the energy metabolism or by the stimulation of this metabolism and restoration of tissue redox equilibrium

  4. Enhanced Radiosensitivity of Tumor Cells Treated with Vanadate in Vitro

    International Nuclear Information System (INIS)

    Lee, Myung Za; Lee, Won Young

    1994-01-01

    Intracellular ions which have a major role in cellular function have been reported to affect repair of radiation damage. Recently it has been reported that ouabain sensitizes A549 tumor cells hut not CCL-120 normal cells to radiation. Ouabain inhibits the Na+-K+-pump rapidly thus it increases intracellular Na concentration. Vanadate which is distributed extensively in almost all living organisms in known to be a Na+-K+-ATPase inhibitors. This study was performed to see any change in radiosensitivity of tumor cell by vanadate and any role of Na+-K+-ATPase in radiosensitization. Experiments have been carried out by pretreatment with vanadate in human cell line(A549, JMG) and mouse cell line(L1210, spleen). For the cell survival MTT assay was performed for A549 and JMG cell and trypan blue dye exclusion test for L120, and spleen cells. Measurements of Na+-K+-ATPase activity in control, vanadate treated cell, radiation treated cell (9 Gy for A549 and JMG, 2 Gy for L1201, spleen), and combined 10-6 M vanadate and radiation treated cells were done. The results were summarized as follows. 1. L1210 cell was most radiosensitive, and spleen cell and JMG cell were intermediate, and A549 cell was least radiosensitive. 2. Minimum or cytotoxicity was seen with vanadate below concentration of 10-6 M. 3. In A549 cells there was a little change in radiosensitivity with treatment of vanadate. However radiation sensitization was shown in low dose level of radiation i. E. 2-Gy. In JMG cells no change in radiosensitivity was noted. Both L1210 and spleen cell had radiosensitization but change was greater in tumor cell. 4. Na+-K+-ATPase activity was inhibited significantly in tumor cell by treatment of vanadate. 5. Radiation itself inhibited Na+-K+-ATPase activity of tumor cell with high Na+- K+-ATPase concention. Increase in radiosensitivity by vanadate was closely associated with original Na+-K+-ATPase contents. From the above results vanadate had little cytotoxicity and it sensitized

  5. Can extremely enhanced clinical sensitivity to radiotherapy be detected by measuring chromosomal damage in lymphocytes in vitro?

    International Nuclear Information System (INIS)

    Dunst, J.; Gebhart, E.; Neubauer, S.

    1995-01-01

    We have examined the in-vitro radiosensitivity of lymphocytes in patients with extreme acute and chronic reactions after curative radiotherapy under the assumption of increased genetic radiosensitivity. 16 patients were retrospectively examined 1 to 108 months after radiotherapy. All had undergone definitive or postoperative curative radiotherapy for cancer. None of them had known genetic disorders with increased radiosensitivity. 4 patients were considered as having probably increased radiosensitivity; they had shown poor tolerance to radiotherapy (1 severe acute reaction with cessation of radiotherapy in bladder cancer and subsequent bladder shrinkage after 45 Gy, 1 acute skin reaction well above average with subsequent fibrosis after irradiation for regional recurrence of breast cancer, 1 radiation myelitis after palliative irradiation with 5 x 5 Gy for lung cancer, 1 severe acute reaction after mediastinal irradiation for lung cancer). 12 patients were considered as having normal tolerance to radiotherapy. They had tolerated radiotherapy well with normal acute reactions and no or minimal signs of late radiation sequelae. Lymphocyte cultures were prepared from all patients and irradiated with 0.7 and 2 Gy, respectively; 1 culture served as control (0 Gy). Chromosomes 1, 2 and 4 were stained using fluorescence in-situ hybridization (FISH) with a 3-colour-chromosome-in-situ suppression technique. Chromosomal breaks were counted in 200 to 1000 mitoses. The 4 patients with increased clinical radiation sensitivity showed also increased chromosomal radiation induced damage as compared to the 12 patients with normal radiation tolerance. Patients with increased clinical radiosensitivity exhibited increased chromosomal damage in lymphocytes in vitro measured with chromosome painting with a FISH-technique. This technique may be used to detect patients with severely enhanced radiosensitivity. The results suggest that if radiosensitivity is abnormally elevated this may be

  6. SU-E-T-168: Evaluation of Normal Tissue Damage in Head and Neck Cancer Treatments

    International Nuclear Information System (INIS)

    Ai, H; Zhang, H

    2014-01-01

    Purpose: To evaluate normal tissue toxicity in patients with head and neck cancer by calculating average survival fraction (SF) and equivalent uniform dose (EUD) for normal tissue cells. Methods: 20 patients with head and neck cancer were included in this study. IMRT plans were generated using EclipseTM treatment planning system by dosimetrist following clinical radiotherapy treatment guidelines. The average SF for three different normal tissue cells of each concerned structure can be calculated from dose spectrum acquired from differential dose volume histogram (DVH) using linear quadratic model. The three types of normal tissues include radiosensitive, moderately radiosensitive and radio-resistant that represents 70%, 50% and 30% survival fractions, respectively, for a 2-Gy open field. Finally, EUDs for three types of normal tissue of each structure were calculated from average SF. Results: The EUDs of the brainstem, spinal cord, parotid glands, brachial plexus and etc were calculated. Our analysis indicated that the brainstem can absorb as much as 14.3% of prescription dose to the tumor if the cell line is radiosensitive. In addition, as much as 16.1% and 18.3% of prescription dose were absorbed by the brainstem for moderately radiosensitive and radio-resistant cells, respectively. For the spinal cord, the EUDs reached up to 27.6%, 35.0% and 42.9% of prescribed dose for the three types of radiosensitivities respectively. Three types of normal cells for parotid glands can get up to 65.6%, 71.2% and 78.4% of prescription dose, respectively. The maximum EUDs of brachial plexsus were calculated as 75.4%, 76.4% and 76.7% of prescription for three types of normal cell lines. Conclusion: The results indicated that EUD can be used to quantify and evaluate the radiation damage to surrounding normal tissues. Large variation of normal tissue EUDs may come from variation of target volumes and radiation beam orientations among the patients

  7. Tumour radiosensitization with the halogenated pyrimidines 5'-bromo-and 5'-iododeoxyuridine

    Energy Technology Data Exchange (ETDEWEB)

    Epstein, A.H.; Cook, J.A.; Goffman, T. (National Cancer Inst., Bethesda, MD (United States)); Glatstein, E. (Texas Univ., Dallas, TX (United States). Southwestern Medical Center)

    1993-02-01

    The authors review studies of the use of iododeoxyuridine (IdUrd) and bromodeoxyuridine as radiosensitizers and attempt to correlate the clinical outcome for patients treated with radiation and IdUrd with the extent of halogenated pyrimidine cellular uptake and incorporation. (U.K.).

  8. Metronidazole as a radiosensitizer: a preliminary report on estimation in serum and saliva

    International Nuclear Information System (INIS)

    Karim, A.B.M.F.; Faber, D.B.; Haas, R.E.; Hoekstra, F.H.; Njo, K.H.

    1980-01-01

    Some studies indicate the clinical benefit of hypoxic radiosensitizers in patients who are undergoing radiotherapy. Serum level of sensitizers are usualy advised; however they are very demanding on the patient. Saliva level of the sensitizers may be an alternative method. This study correlated serum level of metronidazole to the saliva level in 10 patients who were undergoing radiotherapy with the sensitizer. A change to the saliva level method appears to relieve the patients

  9. Patterns of care in patients with cervical cancer 2012. Results of a survey among German radiotherapy departments and out-patient health care centers

    International Nuclear Information System (INIS)

    Marnitz, S.; Rauer, A.; Budach, V.; Koehler, C.; Schneider, A.; Mangler, M.; Tsunoda, A.

    2014-01-01

    Platinum-based primary or adjuvant chemoradiation is the treatment of choice for patients with cervical cancer. However, despite national guidelines and international recommendations, many aspects in diagnosis, therapy, and follow-up of patients with cervical cancer are not based on valid data. To evaluate the current patterns of care for patients with cervical cancer in Germany, a questionnaire with 25 items was sent to 281 radiooncologic departments and out-patient health care centers. The response rate was 51 %. While 87 % of institutions treat 0-25 patients/year, 12 % treat between 26 and 50 and only 1 % treat more than 50 patients/year. In 2011, the stage distribution of 1,706 treated cervical cancers were IB1, IB2, IIA, IIB, IIIA/IIIB, and IV in 11, 12, 11, 22, 28, and 16 %, respectively. CT (90 %) and MRI (86 %) are mainly used as staging procedures in contrast to PET-CT with 14 %. Interestingly, 27 % of institutions advocate surgical staging prior to chemoradiation. In the majority of departments 3D-based (70 %) and intensity-modulated radiotherapy (76 %) are used for percutaneous radiation, less frequently volumetric arc techniques (26 %). Nearly all colleagues (99.3 %) apply conventional fractioning of 1.8-2 Gy for external-beam radiotherapy, in 19 % combined with a simultaneous integrated boost. Cisplatinum mono is used as a radiosensitizer with 40 mg/m 2 weekly by 90 % of radiooncologists. For boost application in the primary treatment, HDR (high-dose rate) brachytherapy is the dominant technique (84 %). In patients after radical hysterectomy pT1B1/1B2, node negative and resection in sound margins adjuvant chemoradiation is applied due to the occurrence of 1-4 other risk factors in 16-97 %. There is a broad spectrum of recommended primary treatment strategies in stages IIB and IVA. Results of the survey underline the leading role but also differences in the use of chemoradiation in the treatment of cervical cancer patients in Germany. (orig.) [de

  10. Cellular Pathways in Response to Ionizing Radiation and Their Targetability for Tumor Radiosensitization

    Directory of Open Access Journals (Sweden)

    Patrick Maier

    2016-01-01

    Full Text Available During the last few decades, improvements in the planning and application of radiotherapy in combination with surgery and chemotherapy resulted in increased survival rates of tumor patients. However, the success of radiotherapy is impaired by two reasons: firstly, the radioresistance of tumor cells and, secondly, the radiation-induced damage of normal tissue cells located in the field of ionizing radiation. These limitations demand the development of drugs for either radiosensitization of tumor cells or radioprotection of normal tissue cells. In order to identify potential targets, a detailed understanding of the cellular pathways involved in radiation response is an absolute requirement. This review describes the most important pathways of radioresponse and several key target proteins for radiosensitization.

  11. 3D cell cultures of human head and neck squamous cell carcinoma cells are radiosensitized by the focal adhesion kinase inhibitor TAE226

    International Nuclear Information System (INIS)

    Hehlgans, Stephanie; Lange, Inga; Eke, Iris; Cordes, Nils

    2009-01-01

    Background and purpose: Focal adhesion kinase (FAK), a main player in integrin signaling and survival, is frequently overexpressed in human cancers and therefore postulated as potential target in cancer therapy. The aim of this study was to evaluate the radiosensitizing potential of the FAK inhibitor TAE226 in three-dimensional (3D) tumor cell cultures. Materials and methods: Head and neck squamous cell carcinoma (HNSCC) cells (FaDu, UT-SCC15, UT-SCC45), lung cancer cells (A549), colorectal carcinoma cells (DLD-1, HCT-116) and pancreatic tumor cells (MiaPaCa2, Panc1) were treated with different concentrations of TAE226 (0-1 μm; 1 or 24 h) without or in combination with irradiation (0-6 Gy, X-ray, single dose). Subsequently, 3D clonogenic survival assays (laminin-rich extracellular matrix) and Western blotting (expression/phosphorylation, e.g. FAK, Akt, ERK1/2) were performed. Results: All investigated 3D cell cultures showed a dose-dependent reduction in clonogenic survival by TAE226. Intriguingly, TAE226 only significantly radiosensitized 3D HNSCC cell cultures accompanied by a pronounced dephosphorylation of FAK, Akt and ERK1/2. Conclusions: Our data demonstrate TAE226 as potent FAK inhibitor that enhances the cellular radiosensitivity particularly of HNSCC cells grown in a 3D cell culture model. Future in vitro and in vivo investigations will clarify, to which extent this approach might be clinically relevant for radiotherapy of HNSCC.

  12. A ruthenium polypyridyl intercalator stalls DNA replication forks, radiosensitizes human cancer cells and is enhanced by Chk1 inhibition

    Science.gov (United States)

    Gill, Martin R.; Harun, Siti Norain; Halder, Swagata; Boghozian, Ramon A.; Ramadan, Kristijan; Ahmad, Haslina; Vallis, Katherine A.

    2016-08-01

    Ruthenium(II) polypyridyl complexes can intercalate DNA with high affinity and prevent cell proliferation; however, the direct impact of ruthenium-based intercalation on cellular DNA replication remains unknown. Here we show the multi-intercalator [Ru(dppz)2(PIP)]2+ (dppz = dipyridophenazine, PIP = 2-(phenyl)imidazo[4,5-f][1,10]phenanthroline) immediately stalls replication fork progression in HeLa human cervical cancer cells. In response to this replication blockade, the DNA damage response (DDR) cell signalling network is activated, with checkpoint kinase 1 (Chk1) activation indicating prolonged replication-associated DNA damage, and cell proliferation is inhibited by G1-S cell-cycle arrest. Co-incubation with a Chk1 inhibitor achieves synergistic apoptosis in cancer cells, with a significant increase in phospho(Ser139) histone H2AX (γ-H2AX) levels and foci indicating increased conversion of stalled replication forks to double-strand breaks (DSBs). Normal human epithelial cells remain unaffected by this concurrent treatment. Furthermore, pre-treatment of HeLa cells with [Ru(dppz)2(PIP)]2+ before external beam ionising radiation results in a supra-additive decrease in cell survival accompanied by increased γ-H2AX expression, indicating the compound functions as a radiosensitizer. Together, these results indicate ruthenium-based intercalation can block replication fork progression and demonstrate how these DNA-binding agents may be combined with DDR inhibitors or ionising radiation to achieve more efficient cancer cell killing.

  13. Vacuolar-proton-ATPase is involved in the response of cancer cells to ionizing radiation and is a new target for radiosensitization

    International Nuclear Information System (INIS)

    Hollister, T.C.; Paglin, S.; McMahill, M.S.; Gilles, F.; Yahalom, J.

    2001-01-01

    Purpose: We have recently described a novel response of human cancer cells to radiation consisting of accumulation of acidic vesicular organelles (AVO) (Cancer Research, 61:439-444, 2001). Acidification of AVO was inhibited by bafilomycin A1 - a specific inhibitor of vacuolar-proton-ATPase. To examine the role of AVO function in the cellular response to radiation, we determined the effect of specific inhibitors of v-H+-ATPase (bafilomycin and concanamycin) on the clonogenic survival of various cancer cell lines. In addition, Northern analysis of mRNA encoding v-H+-ATPase was performed to elucidate possible mechanisms of post-radiation v-H+-ATPase regulation. Materials and Methods: Total RNA was isolated from human cancer cell lines including MCF-7 (breast), LoVo (colon), and LNCaP (prostate) cells 48 hours post-irradiation, and Northern analyses were performed. RNA was separated on a denaturing formaldehyde gel and blotted to a nylon membrane. Probes made from cDNAs to v-H+-ATPase were radioactively labeled, hybridized to the membranes, and exposed to X-ray film for determination of mRNA expression levels. Clonogenic survival assays were performed with MCF-7 and LoVo cell lines. Cells were plated at 30 cells/cm 2 , and irradiated 24 hours post-plating. Bafilomycin or concanamycin were added to culture media in various concentrations at the time of irradiation. The media was changed after a 24-hour incubation, and colonies were stained with crystal violet for counting 7 days post-irradiation. Results: Radiation-induced accumulation of acidic vesicular organelles in MCF-7, LoVo and LNCaP cells was associated with a two-fold increase in the steady-state level of mRNA for subunit c of v-H+-ATPase. Bafilomycin and concanamycin increased clonogenic cell death after irradiation in a dose-dependent manner. At low concentrations (bafilomycin 2nM, concanamycin 2pM) these agents acted as radiosensitizers, without significant toxicity to unirradiated cells. At 2nM, bafilomycin

  14. Effect of radiosensitizer BSO on the incidence of micronuclei in cultured cells

    International Nuclear Information System (INIS)

    Jin Yizun; Cai Rongmei; Ding Li; Shen Zhifen; Xu Liming; Yang Jiakuan

    1992-01-01

    The effects of BSO, a potent radiosensitizing and chemical sensitizing chemical, on the incidence of micronuclei in four different cell lines have been studied using the cytokinesis-block (CB) method. The number of micronuclei in cultured human peripheral lymphocytes, Chinese hamster cells and human breast cancer cells were not affected by 0.1-2 mmol/L BSO treatment alone. However, significant increase in the incidence of micronuclei in these cells could be detected when BSO was used in combination with γ-irradiation. Linear relationship between the incidence of micronuclei and the radiation dose was observed

  15. Enhanced intrinsic radiosensitivity after treatment with stereotactic radiosurgery for an acoustic neuroma

    International Nuclear Information System (INIS)

    Adams, Gerard; Martin, Olga A.; Roos, Daniel E.; Lobachevsky, Pavel N.; Potter, Andrew E.; Zacest, Andrew C.; Bezak, Eva; Bonner, William M.; Martin, Roger F.; Leong, Trevor

    2012-01-01

    Enhanced radiosensitivity is an uncommon phenomenon attributable to deficient DNA repair after radiotherapy which can be assessed with the γ-H2AX assay. Reports of radiosensitivity after stereotactic radiosurgery (SRS) are uncommon. We describe a case where the clinical, radiological and laboratory findings suggest enhanced radiosensitivity after SRS for an acoustic neuroma.

  16. Inhibition of cyclic AMP response element-directed transcription by decoy oligonucleotides enhances tumor-specific radiosensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Park, Serk In, E-mail: serkin@korea.edu [Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul (Korea, Republic of); The BK21 Plus Program for Biomedical Sciences, Korea University College of Medicine, Seoul (Korea, Republic of); Department of Medicine and Center for Bone Biology, Vanderbilt University School of Medicine, Nashville, TN (United States); Park, Sung-Jun [Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul (Korea, Republic of); Laboratory of Obesity and Aging Research, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD (United States); Lee, Junghan; Kim, Hye Eun; Park, Su Jin; Sohn, Jeong-Won [Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul (Korea, Republic of); Park, Yun Gyu, E-mail: parkyg@korea.ac.kr [Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul (Korea, Republic of)

    2016-01-15

    The radiation stress induces cytotoxic responses of cell death as well as cytoprotective responses of cell survival. Understanding exact cellular mechanism and signal transduction pathways is important in improving cancer radiotherapy. Increasing evidence suggests that cyclic AMP response element binding protein (CREB)/activating transcription factor (ATF) family proteins act as a survival factor and a signaling molecule in response to stress. We postulated that CREB inhibition via CRE decoy oligonucleotide increases tumor cell sensitization to γ-irradiation-induced cytotoxic stress. In the present study, we demonstrate that CREB phosphorylation and CREB DNA-protein complex formation increased in time- and radiation dose-dependent manners, while there was no significant change in total protein level of CREB. In addition, CREB was phosphorylated in response to γ-irradiation through p38 MAPK pathway. Further investigation revealed that CREB blockade by decoy oligonucleotides functionally inhibited transactivation of CREB, and significantly increased radiosensitivity of multiple human cancer cell lines including TP53- and/or RB-mutated cells with minimal effects on normal cells. We also demonstrate that tumor cells ectopically expressing dominant negative mutant CREB (KCREB) and the cells treated with p38 MAPK inhibitors were more sensitive to γ-irradiation than wild type parental cells or control-treated cells. Taken together, we conclude that CREB protects tumor cells from γ-irradiation, and combination of CREB inhibition plus ionizing radiation will be a promising radiotherapeutic approach. - Highlights: • γ-Irradiation induced CREB phosphorylation and CRE-directed transcription in tumor. • γ-Irradiation-induced transcriptional activation of CREB was via p38 MAPK pathway. • CRE blockade increased radiosensitivity of tumor cells but not of normal cells. • CRE decoy oligonucleotides or p38 MAPK inhibitors can be used as radiosensitizers.

  17. Radio-sensitization by Piper longumine of human breast adenoma MDA-MB-231 cells in vitro.

    Science.gov (United States)

    Yao, Jian-Xin; Yao, Zhi-Feng; Li, Zhan-Feng; Liu, Yong-Biao

    2014-01-01

    The current study investigated the effects of Piper longumine on radio-sensitization of human breast cancer MDA-MB-231 cells and underlying mechanisms. Human breast cancer MDA-MB-231 cells were cultured in vitro and those in logarithmic growth phase were selected for experiments divided into four groups: control, X-ray exposed, Piper longumine, and Piper longumine combined with X-rays. Conogenic assays were performed to determine the radio-sensitizing effects. Cell survival curves were fitted by single-hit multi-target model and then the survival fraction (SF), average lethal dose (D0), quasi-threshold dose (Dq) and sensitive enhancement ratio (SER) were calculated. Cell apoptosis was analyzed by flow cytometry (FCM).Western blot assays were employed for expression of apoptosis-related proteins (Bc1-2 and Bax) after treatment with Piper longumine and/or X-ray radiation. The intracellular reactive oxygen species (ROS) level was detected by FCM with a DCFH-DA probe. The cloning formation capacity was decreased in the group of piperlongumine plus radiation, which displayed the values of SF2, D0, Dq significantly lower than those of radiation alone group and the sensitive enhancement ratio (SER) of D0 was1.22 and 1.29, respectively. The cell apoptosis rate was increased by the combination treatment of Piper longumine and radiation. Piper longumine increased the radiation-induced intracellular levels of ROS. Compared with the control group and individual group, the combination group demonstrated significantly decreased expression of Bcl-2 with increased Bax. Piper longumine at a non-cytotoxic concentration can enhance the radio-sensitivity of MDA- MB-231cells, which may be related to its regulation of apoptosis-related protein expression and the increase of intracellular ROS level, thus increasing radiation-induced apoptosis.

  18. Inhibition of cyclic AMP response element-directed transcription by decoy oligonucleotides enhances tumor-specific radiosensitivity

    International Nuclear Information System (INIS)

    Park, Serk In; Park, Sung-Jun; Lee, Junghan; Kim, Hye Eun; Park, Su Jin; Sohn, Jeong-Won; Park, Yun Gyu

    2016-01-01

    The radiation stress induces cytotoxic responses of cell death as well as cytoprotective responses of cell survival. Understanding exact cellular mechanism and signal transduction pathways is important in improving cancer radiotherapy. Increasing evidence suggests that cyclic AMP response element binding protein (CREB)/activating transcription factor (ATF) family proteins act as a survival factor and a signaling molecule in response to stress. We postulated that CREB inhibition via CRE decoy oligonucleotide increases tumor cell sensitization to γ-irradiation-induced cytotoxic stress. In the present study, we demonstrate that CREB phosphorylation and CREB DNA-protein complex formation increased in time- and radiation dose-dependent manners, while there was no significant change in total protein level of CREB. In addition, CREB was phosphorylated in response to γ-irradiation through p38 MAPK pathway. Further investigation revealed that CREB blockade by decoy oligonucleotides functionally inhibited transactivation of CREB, and significantly increased radiosensitivity of multiple human cancer cell lines including TP53- and/or RB-mutated cells with minimal effects on normal cells. We also demonstrate that tumor cells ectopically expressing dominant negative mutant CREB (KCREB) and the cells treated with p38 MAPK inhibitors were more sensitive to γ-irradiation than wild type parental cells or control-treated cells. Taken together, we conclude that CREB protects tumor cells from γ-irradiation, and combination of CREB inhibition plus ionizing radiation will be a promising radiotherapeutic approach. - Highlights: • γ-Irradiation induced CREB phosphorylation and CRE-directed transcription in tumor. • γ-Irradiation-induced transcriptional activation of CREB was via p38 MAPK pathway. • CRE blockade increased radiosensitivity of tumor cells but not of normal cells. • CRE decoy oligonucleotides or p38 MAPK inhibitors can be used as radiosensitizers.

  19. Radiosensitizing efficiency of sodium glycididazole on V79 cells in vitro

    International Nuclear Information System (INIS)

    Zheng Xiulong; Gao Jianguo; Zhang Hong; Zhu Qin; Meng Xiangshun; Zhao Fang

    1995-01-01

    Radiosensitizing effect of sodium glycididazole (SGDD) on the hypoxic V 79 cells by standard in vitro colon formation method has been further studied. The results showed its toxicity was low. Its ID 50 in cells under hypoxic and aerobic condition were 23.5 and 35.7 mmol/L respectively. These indicated that SGDD showed more toxicity under hypoxic than under aerobic condition (p 1.6 was 0.48 mmol/L. Its maximum SER was 2.3 at 1.38 mmol/L. Comparisons of radiosensitizing effect of SGDD versus MISO and its mother compound (metronidazole) under the same experimental condition, SER for SGDD, MISO and metronidazole were 1.75, 1.53 and 1.07 at 0.3 mmol/L respectively. SGDD showed more radiosensitizing efficiency than MISO and much greater than metronidazole. This study further confirms our previous results i.e. SGDD is a hypoxic radiosensitizer with low toxic, high efficiency and selectively enhances the radiosensitivity of hypoxic cells for tumor radiotherapy

  20. Evaluation of 2-amino-5-nitrothiazole as a hypoxic cell radiosensitizer

    International Nuclear Information System (INIS)

    Rockwell, S.; Mroczkowski, Z.; Rupp, W.D.

    1982-01-01

    The nitroheterocyclic compound 2-amino-5-nitrothiazole (ANT) was evaluated as a hypoxic radiosensitizer. Experiments with bacteria showed that this agent was similar to misonidozole in radiosensitizing activity, but was less cytotoxic and less mutagenic than misonidazole. Experiments with EMT6 tumor cells in culture showed ANT to be an effective hypoxic radiosensitizer, although slightly less active than misonidazole, and to be less cytotoxic than misonidazole. ANT was more toxic to mice than misonidazole and produced a spectrum of symptoms, including hyperactivity and agitation, different from those of misonidazole. The toxicities of ANT and misonidazole were additive. The maximum levels of ANT achieveable in the tumors after ip injection of nontoxic doses of drug were low ( -4 M) and the radiosensitization obtainable with the drug in vivo was inferior to that obtainable with misonidazole. These findings suggest that nitrothiazoles might be an interesting class of nitroheterocyclic radiosensitizers, but that molecules with increased solubility and improved pharmacokinetics would be necessary for efficacy in vivo

  1. Determining and predictive factors for the tumor radiosensitivity

    International Nuclear Information System (INIS)

    Hennequin, Ch.; Quero, L.; Hennequin, Ch.; Quero, L.; Favaudon, V.

    2008-01-01

    Many predictive factors of tumor radiosensitivity have been described. Number of clonogenic cells, proliferation rate, hypoxia and intrinsic radiosensitivity are usually considered as the main parameters of tumor control. Intrinsic radiosensitivity is correlated in a first approach to the ability of the cell to detect and repair DNA damages, and so integrity of the different pathways involved in this function: P.A.R.P.-1, X.R.C.C.1, A.T.M., p 53, M.R.N. complex or B.R.C.A.1. Genetic polymorphisms of some of these genes, found in normal lymphocytes, have been correlated to late toxicity of normal tissues. But, in tumors, because of the difficulty to obtain samplings and heterogeneity, accurate molecular analysis is not possible in many cases, and no valuable test of radiosensitivity exist at this moment. For example, T.P. 53 gene has been evaluated in many studies and results regarding its potential as a predictive factor of tumor sensitivity are conflicting. Surviving fraction at 2 Gy (S.F.2) allowed a global evaluation of sensitivity, but the obtention of this parameter often takes a long time and failed in 20 to 40%. Evaluation of double-strand break repair capacity by immuno chemistry quantification of phosphorylated forms of A.T.M., H.2 A.X. or M.R.E.11 is an interesting topic. However, discovery of tumor stem cells in a number of epithelial tumors could revolutionize the understanding of radiosensitivity. Combination of genomic and functional techniques are probably essential to better predict this parameter. (authors)

  2. Radiosensitivity of Bombyx mori embryos and its modification by thermal shock

    International Nuclear Information System (INIS)

    Agaev, F.A.; Zakrzhevskaya, D.T.; Yusifov, N.I.; Gaziev, A.I.; AN Azerbajdzhanskoj SSR, Baku

    1991-01-01

    Radiosensitivity of Bombyx mori embryos on days 3-4 of their development is more than 10 times higher than that of 7-9 day embryos. The rate of DNA synthesis in the embryos correlates with their radiosensitivity. Heat treatment (40 deg C, 60 min) of embryos just before γ-irradiation increases their radioresistance (DMF=+1.6), whereas such a treatment immediately after irradiation reduces the survival rate of embryos as compared to the controls irradiated without heat treatment (DMA=-1.5). The radiomodifying effect of the thermal shock on the Bombyx mori embryos is the same with exposure at both the radioresistant and the radiosensitive stage of their development. However, it is more pronounced at the radiosensitive stage

  3. Procedures for increasing the radiosensitivity of malignant tumors with special regard to synchronized radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, W

    1975-01-01

    Two principal ways to increase the radiosensitivity of malignant tumours are described: to begin with, both the use of highly ionizing corpuscular radiation - e.g. in neutron therapy - and the simultaneous application of photons and high-pressure oxygen heighten radiosensitivity by increasing the number of secondary hit events. The second principal direction - in which the radiation intervals are timed in dependence of lifetime and division rhythm of the tumour cells - is described and illustrated by results of 5-fluorouracil and /sup 60/Co irradiation of 71 patients. The results show a particularly good response of carcinomas of the ENT region and the breast. Questions of the radiosensitive stage, the time of infusion, the influence of the generation cycle and the influence of oxygen-starved cells on the results are major points for future studies on synchronized radiotherapy. Mathematical calculations are carried out concerning the time of infusion and the influence of the generation cycle. Some consequences are mentioned which had not been dealt with so far in synchronized radiotherapy: high single doses and short intervals between sessions for tumours with short generation and duplication times, and low doses and long intervals for small tumours with slow growth rates. There is no principal difference between oxygen-starved and oxygen-rich cells as far as the dependence of radiosensitivity on the generation cycle - i.e. the starting point of synchronized radiotherapy - is concerned.

  4. Cell killing and radiosensitization by caffeic acid phenethyl ester (CAPE) in lung cancer cells

    International Nuclear Information System (INIS)

    Chen, Miao-Fen; Chen, Wen-Cheng; Wu, Chun-Te; King, P.C.

    2004-01-01

    Caffeic acid phenethyl ester (CAPE) is a biologically active ingredient of honeybee propoplis. The cytotoxicity and radiation sensitization effects of CAPE were evaluated in human lung cancer A549 cells and normal lung fibroblast WI-38 cells. A549 cells treated with 6 μg/ml CAPE showed marked growth inhibition (60%) at 48 hr after treatments. During the same time, the number of viable cells decreased to 46% of the control value. In contrast, WI-38 cells showed 20% growth inhibition with no change in the number of viable cells under the same treatment conditions. At 72 hr after CAPE treatment (6 μg/ml), the percentage of apoptotic cells in A549 cultures increased significantly to 67% and an S/G2 arrest was also detected in the culture. Furthermore, there was a significant decrease in the level of intracellular glutathione and hydrogen peroxide contents within one hr after CAPE treatment, and the expression of cyclin B 1 was reduced 6 hr after treatment. The radiation sensitization effect of CAPE on A549 cells was determined from the clonogenic survival curves, and the results showed a small but significant difference in radiation survival between cells treated with or without CAPE. Taken together, our results suggest that the effects of CAPE on differential cytotoxicity, apoptosis, and radiosensitization are associated with glutathione depletion that occurred shortly after treatments. (author)

  5. Modulation of radiosensitivity by growth factors

    International Nuclear Information System (INIS)

    Paris, F.

    2013-01-01

    The full text of the publication follows. For the past 70 years, radiotherapy protocols were defined to target and kill cancer cells. New research developments showed that the tissue or tumor radiosensitivities might be directly modulated by its own microenvironment. Between all the micro-environmental cells, endothelial cells are playing a unique role due to the need of angio-genesis for tumor genesis and to the microvascular endothelial cell apoptosis involved in acute normal tissue and tumor radiosensitivities. Both endothelial behaviours may be controlled by specific growth factors secreted by tumor cells. Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) are two cytokines involved in angio genesis and endothelial cell survival. Because radiation exposure develops opposite molecular and cellular responses by inhibiting proliferation and by enhancing apoptosis, inhibiting these cytokines has been proposed as a relevant strategy to improve radiotherapy efficiency. Drugs or antibody against VEGF, or other growth factors have been used with success to limit endothelial cell resistance, but also to transiently normalize of blood vessels to improve oxygen distribution into the tumor. However, better characterisation of the role of the cytokines will help to better improve the strategy of the use of their antagonists. We demonstrate that bFGF or sphingosin 1 phosphate (S1P), a lipid endothelial growth factor, protects endothelial cells from radiation stress by inhibiting the pre-mitotic apoptosis through enhancement of pro-survival molecular cascade, such as the Pi3K/AKT pathway, but not post-mitotic death. This discrepancy allowed a specific use of S1P as pharmacological drug protecting quiescent endothelial cells, present in normal tissue blood vessels, but not in proliferating angiogenic blood vessels, majority present in tumor blood vessel. In vivo studies are underway. (author)

  6. A role for survivin in radioresistance of pancreatic cancer cells

    International Nuclear Information System (INIS)

    Asanuma, Koichi; Kobayashi, Daisuke; Furuya, Daisuke; Tsuji, Naoki; Yagihashi, Atsuhito; Watanabe, Naoki

    2002-01-01

    Using gene-transduced pancreatic cancer cells, we examined whether survivin expression is directly involved in regulation of radiosensitivity. Ordinarily radiosensitive MIAPaCa-2 cells transduced with wild-type survivin gene (MS cells) proliferated more rapidly than cells transduced with control vector. MS cells were significantly less radiosensitive than control vector-transduced cells. Radiation-induced activity of caspase-3, but not caspase-7, was significantly inhibited in MS cells. On the other hand, transduction of a dominant-negative mutant survivin gene into radioresistant PANC-1 cells augmented radiosensitivity. Further, the radiation-induced increase in caspase-3 activity was enhanced, indicating that survivin function was truly inhibited. These results indicate that survivin expression directly down-regulates radiosensitivity. (author)

  7. The small molecule inhibitor QLT0267 Radiosensitizes squamous cell carcinoma cells of the head and neck.

    Directory of Open Access Journals (Sweden)

    Iris Eke

    Full Text Available BACKGROUND: The constant increase of cancer cell resistance to radio- and chemotherapy hampers improvement of patient survival and requires novel targeting approaches. Integrin-Linked Kinase (ILK has been postulated as potent druggable cancer target. On the basis of our previous findings clearly showing that ILK transduces antisurvival signals in cells exposed to ionizing radiation, this study evaluated the impact of the small molecule inhibitor QLT0267, reported as putative ILK inhibitor, on the cellular radiation survival response of human head and neck squamous cell carcinoma cells (hHNSCC. METHODOLOGY/PRINCIPAL FINDINGS: Parental FaDu cells and FaDu cells stably transfected with a constitutively active ILK mutant (FaDu-IH or empty vectors, UTSCC45 cells, ILK(floxed/floxed(fl/fl and ILK(-/- mouse fibroblasts were used. Cells grew either two-dimensionally (2D on or three-dimensionally (3D in laminin-rich extracellular matrix. Cells were treated with QLT0267 alone or in combination with irradiation (X-rays, 0-6 Gy single dose. ILK knockdown was achieved by small interfering RNA transfection. ILK kinase activity, clonogenic survival, number of residual DNA double strand breaks (rDSB; gammaH2AX/53BP1 foci assay, cell cycle distribution, protein expression and phosphorylation (e.g. Akt, p44/42 mitogen-activated protein kinase (MAPK were measured. Data on ILK kinase activity and phosphorylation of Akt and p44/42 MAPK revealed a broad inhibitory spectrum of QLT0267 without specificity for ILK. QLT0267 significantly reduced basal cell survival and enhanced the radiosensitivity of FaDu and UTSCC45 cells in a time- and concentration-dependent manner. QLT0267 exerted differential, cell culture model-dependent effects with regard to radiogenic rDSB and accumulation of cells in the G2 cell cycle phase. Relative to corresponding controls, FaDu-IH and ILK(fl/fl fibroblasts showed enhanced radiosensitivity, which failed to be antagonized by QLT0267. A

  8. Radiation dose rate affects the radiosensitization of MCF-7 and HeLa cell lines to X-rays induced by dextran-coated iron oxide nanoparticles.

    Science.gov (United States)

    Khoshgard, Karim; Kiani, Parvaneh; Haghparast, Abbas; Hosseinzadeh, Leila; Eivazi, Mohammad Taghi

    2017-08-01

    The aim of radiotherapy is to deliver lethal damage to cancerous tissue while preserving adjacent normal tissues. Radiation absorbed dose of the tumoral cells can increase when high atomic nanoparticles are present in them during irradiation. Also, the dose rate is an important aspect in radiation effects that determines the biological results of a given dose. This in vitro study investigated the dose-rate effect on the induced radiosensitivity by dextran-coated iron oxide in cancer cells. HeLa and MCF-7 cells were cultured in vitro and incubated with different concentrations of dextran-coated iron oxide nanoparticles. They were then irradiated with 6 MV photons at dose rates of 43, 185 and 370 cGy/min. The MTT test was used to obtain the cells' survival after 48 h of irradiations. Incubating the cells with the nanoparticles at concentrations of 10, 40 and 80 μg/ml showed no significant cytotoxicity effect. Dextran-coated iron oxide nanoparticles showed more radiosensitivity effect by increasing the dose rate and nanoparticles concentration. Radiosensitization enhancement factors of MCF-7 and HeLa cells at a dose-rate of 370 cGy/min and nanoparticles' concentration of 80 μg/ml were 1.21 ± 0.06 and 1.19 ± 0.04, respectively. Increasing the dose rate of 6 MV photons irradiation in MCF-7 and HeLa cells increases the radiosensitization induced by the dextran-coated iron nanoparticles in these cells.

  9. Radiosensitivities of cultured barley of different type (Hordeum vulgare)

    International Nuclear Information System (INIS)

    Wang Cailian; Shen Mei; Xu Gang; Zhao Kongnan

    1990-01-01

    The dormant seeds (with 13% moisture) of 47 barley varieties were irradiated with various doses (0-40 krad) of 137 Cs γ-rays. The radiosensitivities of naked barley was significantly higher than that of hulled barley. The sensitive coefficients of seedling height were 0.04945 and 0.03667 for naked barley and hulled barley, respectively. The radiosensitivity of four-row naked barley was significantly higher than that of two-row hulled barley and six-row hulled barley. 47 varieties studied could be divided into five types with different radiosensitivities, i.e. extreme resistant, resistant, intermediate, sensitive and extreme sensitive. It was also found that the dose-effect curves of cell nucleus volume had a peal at 30 krad

  10. The molecular basis of radiosensitivity

    International Nuclear Information System (INIS)

    McMillan, T.J.

    1989-01-01

    This paper considers how DNA damage induced by ionising radiation is processed within the cell. The current view of radiobiology is discussed. The author explains the molecular processes that underlie the differences in radiosensitivity

  11. The progress of radiosensitive genes of human brain glioma

    International Nuclear Information System (INIS)

    Wang Xi; Liu Qiang

    2008-01-01

    Human gliomas are one of the most aggressive tumors in brain which grow infiltrativly. Surgery is the mainstay of treatment. But as the tumor could not be entirely cut off, it is easy to relapse. Radiotherapy plays an important role for patients with gliomas after surgery. The efficacy of radiotherapy is associated with radio sensitivity of human gliomas. This paper makes a summary of current situation and progress for radiosensitive genes of human brain gliomas. (authors)

  12. Technical knowledge assessment in radiology in patients protection in collective environments and more radiosensitive organs

    International Nuclear Information System (INIS)

    Costa, R.F.

    2015-01-01

    The use of X-rays in medical fields has increased significantly in recent years, since various therapeutic procedures can be performed without the need for surgery, which presents the greatest risk to the patient. An example of this increase is the practice of cardiac catheterization, this procedure fluoroscopy is used for placement of central venous catheters and temporary pacemakers, and long-term use increases the risk of exposure to X-rays to the patient, doctor and his assistants. This has been observed with concern by many researchers, since many companies did not fit the standards of radiation protection. This failure can lead to exposure of professionals, patients and caregivers. It is therefore of fundamental importance, the use of personal protective equipment such as aprons and thyroid plumbíferos protectors, for dose reduction produced by the primary and secondary radiation. This study evaluated the knowledge of radiology professionals in Goiânia, on the use of lead apron in collective environments and use of guards in sensitive parts of patients to radiation. Through an information gathering technique based on a questionnaire with closed questions. From dista and focuses on the knowledge of professionals. The results showed that there is a serious deficiency as regards the most radiosensitive organ protection of patients when they are exposed to X-ray beams. (author)

  13. Optimal energy for cell radiosensitivity enhancement by gold nanoparticles using synchrotron-based monoenergetic photon beams

    Directory of Open Access Journals (Sweden)

    Rahman WN

    2014-05-01

    Full Text Available Wan Nordiana Rahman,1,2 Stéphanie Corde,3,4 Naoto Yagi,5 Siti Aishah Abdul Aziz,1 Nathan Annabell,2 Moshi Geso21School of Health Sciences, Universiti Sains Malaysia, Kelantan, Malaysia; 2Division of Medical Radiation, School of Medical Sciences, Royal Melbourne Institute of Technology, Bundoora, VIC, 3Radiation Oncology, Prince of Wales Hospital, High Street, Randwick, 4Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia; 5Japanese Synchrotron Radiation Research Institute, Sayo-gun, Hyogo, JapanAbstract: Gold nanoparticles have been shown to enhance radiation doses delivered to biological targets due to the high absorption coefficient of gold atoms, stemming from their high atomic number (Z and physical density. These properties significantly increase the likelihood of photoelectric effects and Compton scattering interactions. Gold nanoparticles are a novel radiosensitizing agent that can potentially be used to increase the effectiveness of current radiation therapy techniques and improve the diagnosis and treatment of cancer. However, the optimum radiosensitization effect of gold nanoparticles is strongly dependent on photon energy, which theoretically is predicted to occur in the kilovoltage range of energy. In this research, synchrotron-generated monoenergetic X-rays in the 30–100 keV range were used to investigate the energy dependence of radiosensitization by gold nanoparticles and also to determine the photon energy that produces optimum effects. This investigation was conducted using cells in culture to measure dose enhancement. Bovine aortic endothelial cells with and without gold nanoparticles were irradiated with X-rays at energies of 30, 40, 50, 60, 70, 81, and 100 keV. Trypan blue exclusion assays were performed after irradiation to determine cell viability. Cell radiosensitivity enhancement was indicated by the dose enhancement factor which was found to be maximum at 40 keV with a value of 3

  14. Targeting Phosphatidylinositol 4-Kinase IIIα for Radiosensitization: A Potential Model of Drug Repositioning Using an Anti-Hepatitis C Viral Agent

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Jeanny [Department of Radiation Oncology, Graduate School of Medicine, Seoul National University, Seoul (Korea, Republic of); Kim, Dan Hyo; Park, Ji Min [Medical Science Research Institute, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of); Park, Young Hee [Department of Radiation Oncology, Graduate School of Medicine, Seoul National University, Seoul (Korea, Republic of); Hwang, Yeo Hyun [Medical Science Research Institute, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of); Wu, Hong-Gyun [Department of Radiation Oncology, Graduate School of Medicine, Seoul National University, Seoul (Korea, Republic of); Institute of Radiation Medicine, Seoul National University, Seoul (Korea, Republic of); Shin, Kyung Hwan [Department of Radiation Oncology, Graduate School of Medicine, Seoul National University, Seoul (Korea, Republic of); Kim, In Ah, E-mail: inah228@snu.ac.kr [Department of Radiation Oncology, Graduate School of Medicine, Seoul National University, Seoul (Korea, Republic of); Medical Science Research Institute, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of); Institute of Radiation Medicine, Seoul National University, Seoul (Korea, Republic of); Cancer Research Institute, Seoul National University, Seoul (Korea, Republic of)

    2016-11-15

    Purpose: To investigate which isotype of phosphatidylinositol 4-kinase (PI4K) may affect radiosensitivity and examine whether anti–hepatitis C viral (HCV) agents, some of which have been shown to inhibit PI4K IIIα activity, could be repositioned as a radiosensitizer in human cancer cells. Methods and Materials: U251, BT474, and HepG2 cell lines and normal human astrocyte were used. Ribonucleic acid interference, clonogenic assays, Western blotting, immunofluorescence, annexin V assay, lysotracker staining, and β-galactosidase assay were performed. Results: Of the 4 PI4K isotypes, specific inhibition of IIIα increased radiosensitivity. For pharmacologic inhibition of PI4K IIIα, we screened 9 anti-HCV agents by half-maximal inhibitory concentration assay. Simeprevir was selected, and its inhibition of PI4K IIIα activity was confirmed. Combination of simeprevir treatment and radiation significantly attenuated expression of phospho-phospho-PKC and phospho-Akt and increased radiation-induced cell death in tested cell lines. Pretreatment with simeprevir prolonged γH2AX foci formation and down-regulation of phospho-DNA-PKcs, indicating impairment of nonhomologous end-joining repair. Cells pretreated with simeprevir exhibited mixed modes of cell death, including apoptosis and autophagy. Conclusion: These data demonstrate that targeting PI4K IIIα using an anti-HCV agent is a viable approach to enhance the therapeutic efficacy of radiation therapy in various human cancers, such as glioma, breast, and hepatocellular carcinoma.

  15. Evaluation of Acute Locoregional Toxicity in Patients With Breast Cancer Treated With Adjuvant Radiotherapy in Combination With Bevacizumab

    International Nuclear Information System (INIS)

    Goyal, Sharad; Rao, Malay S.; Khan, Atif; Huzzy, Lien; Green, Camille; Haffty, Bruce G.

    2011-01-01

    Purpose: Preclinical studies have shown that bevacizumab combined with radiotherapy (RT) induces a radiosensitizing effect. Published reports regarding the safety of combination therapy involving bevacizumab and RT are lacking. The purpose of this study was to analyze acute locoregional toxicity in patients with breast cancer receiving concurrent bevacizumab plus RT. Methods and Materials: After institutional review board approval was obtained, patients with breast cancer who received bevacizumab were identified; these patients were then cross-referenced with patients receiving RT. Toxicity was scored by the Common Terminology Criteria for Adverse Events. Patients were matched 1:1 with those who did not receive bevacizumab. Statistical analysis was performed to analyze toxicity between the two groups. Results: Fourteen patients were identified to have received bevacizumab plus RT. All patients receivedbevacizumab during RT without delay or treatment breaks; there were no RT treatment breaks in all patients. No patient receiving bevacizumab plus RT experienced ≥Grade 3 toxicity; 3 matched control patients experienced a Grade 3 skin reaction. There was no difference in fatigue, radiation fibrosis, pneumonitis, or lymphedema between the two groups. Five patients (35%) developed reduction in ejection fraction; 2 with right-sided and 3 with left-sided treatment. Patients with left-sided treatment experienced a persistent reduction in ejection fraction compared with those receiving right-sided treatment. Conclusion: Concurrent bevacizumab and RT did not increase acute locoregional toxicity in comparison with matched control patients who did not receive RT alone. The addition of concurrent RT when treating the intact breast, chest wall, and associated nodal regions in breast cancer seems to be safe and well tolerated.

  16. Correlation of RAD51 and radiosensitization of methotrexate

    International Nuclear Information System (INIS)

    Du Liqing; Bai Jianqiang; Liu Qiang; Wang Yan; Zhao Peng; Chen Fenghua; Wang Hong; Fan Feiyue

    2012-01-01

    Objective: To evaluate the correlation between homologous recombination repair protein RAD51 and methotrexate-enhanced radiosensitivity. Methods: Western blot and RT-PCR assays were used to detect RAD51 expression in HOS osteosarcoma cells exposed to γ-ray irradiation alone and in combination with methotrexate. Colony formation assay was used to test the survival fraction of HOS cells exposed to γ-rays and methotrexate. Results: Methotrexate inhibited both protein and RNA expressions of RAD51, and the combination of radiation and methotrexate enhanced the inhibition of RAD51 expression. Moreover, transfection of cells with RAD51 gene decreased cellular sensitivity to methotrexate and γ-rays. The sensitizer enhancement ratios after irradiation in combination with methotrexate were 1.51 and 0.99, respectively. Methotrexate was a preferred radiosensitizer to HOS cell. Conclusions: RAD51 might be involved in the methotrexate-enhanced radiosensitivity. (authors)

  17. Evaluation of radioinduced damage and repair capacity in blood lymphocytes of breast cancer patients

    Directory of Open Access Journals (Sweden)

    P.A. Nascimento

    2001-02-01

    Full Text Available Genetic damage caused by ionizing radiation and repair capacity of blood lymphocytes from 3 breast cancer patients and 3 healthy donors were investigated using the comet assay. The comets were analyzed by two parameters: comet tail length and visual classification. Blood samples from the donors were irradiated in vitro with a 60Co source at a dose rate of 0.722 Gy/min, with a dose range of 0.2 to 4.0 Gy and analyzed immediately after the procedure and 3 and 24 h later. The basal level of damage and the radioinduced damage were higher in lymphocytes from breast cancer patients than in lymphocytes from healthy donors. The radioinduced damage showed that the two groups had a similar response when analyzed immediately after the irradiations. Therefore, while the healthy donors presented a considerable reduction of damage after 3 h, the patients had a higher residual damage even 24 h after exposure. The repair capacity of blood lymphocytes from the patients was slower than that of lymphocytes from healthy donors. The possible influence of age, disease stage and mutations in the BRCA1 and BRCA2 genes are discussed. Both parameters adopted proved to be sensitive and reproducible: the dose-response curves for DNA migration can be used not only for the analysis of cellular response but also for monitoring therapeutic interventions. Lymphocytes from the breast cancer patients presented an initial radiosensitivity similar to that of healthy subjects but a deficient repair mechanism made them more vulnerable to the genotoxic action of ionizing radiation. However, since lymphocytes from only 3 patients and 3 normal subjects were analyzed in the present paper, additional donors will be necessary for a more accurate evaluation.

  18. Formation of radical anions of radiosensitizers and related model compounds via electrospray ionization

    DEFF Research Database (Denmark)

    Feketeová, Linda; Albright, Abigail L; Sørensen, Brita Singers

    2014-01-01

    Radiosensitizers are used in radiotherapy to enhance tumour control of radioresistant hypoxic tumours. While the detailed mechanism of radiosensitization is still unknown, the formation of radical anions is believed to be a key step. Thus understanding the ionization reactions of radiosensitizers......, misonidazole and related compounds using a hybrid linear ion trap – Fourier Transform Ion Cyclotron Resonance mass spectrometer (Finnigan-LTQ-FT). A key finding is that negative electrospray ionization of these radiosensitizers leads to the formation of radical anions, allowing their fragmentation reactions...

  19. Radiation safety aspects pertaining to female patients and staff

    International Nuclear Information System (INIS)

    Patni, Nidhi

    2017-01-01

    Many organizations in the world are committed to gender parity. Increasing number of women is working in the fields of radiation medicine and in industries dealing with radiation. Women patients may be exposed to radiation in radiology, radiation oncology, nuclear medicine, interventional cardiology, dentistry etc. Radiation safety of women staff and women patients is different from their male counterparts because of conception and pregnancy. So, fetal health is a matter of concern in the above. Also, the excess relative risk of radiation induced cancers in females relates to higher risk of thyroid cancer and high radiosensitivity as compared to males

  20. Breast cancer stem cell-like cells are more sensitive to ionizing radiation than non-stem cells: role of ATM.

    Directory of Open Access Journals (Sweden)

    Seog-Young Kim

    Full Text Available There are contradictory observations about the different radiosensitivities of cancer stem cells and cancer non-stem cells. To resolve these contradictory observations, we studied radiosensitivities by employing breast cancer stem cell (CSC-like MDA-MB231 and MDA-MB453 cells as well as their corresponding non-stem cells. CSC-like cells proliferate without differentiating and have characteristics of tumor-initiating cells [1]. These cells were exposed to γ-rays (1.25-8.75 Gy and survival curves were determined by colony formation. A final slope, D(0, of the survival curve for each cell line was determined to measure radiosensitivity. The D(0 of CSC-like and non-stem MDA-MB-453 cells were 1.16 Gy and 1.55 Gy, respectively. Similar results were observed in MDA-MB-231 cells (0.94 Gy vs. 1.56 Gy. After determination of radiosensitivity, we investigated intrinsic cellular determinants which influence radiosensitivity including cell cycle distribution, free-radical scavengers and DNA repair. We observed that even though cell cycle status and antioxidant content may contribute to differential radiosensitivity, differential DNA repair capacity may be a greater determinant of radiosensitivity. Unlike non-stem cells, CSC-like cells have little/no sublethal damage repair, a low intracellular level of ataxia telangiectasia mutated (ATM and delay of γ-H2AX foci removal (DNA strand break repair. These results suggest that low DNA repair capacity is responsible for the high radiosensitivity of these CSC-like cells.

  1. Correlation between radiosensitivity of transplanted solid tumor and nutritive condition of host animal

    Energy Technology Data Exchange (ETDEWEB)

    Ando, K [Showa Univ., Tokyo (Japan). School of Medicine

    1975-04-01

    Studies on radiosensitivity of the transplanted tumor were carried out and the following results were obtained: 1. Radiosensitivity of the tumor ran parallel to the growth rate. 2. Malnutrition of the host after irradiation made the tumor radiosensitive, probably because the sublethally damaged tumor cell did not recover. 3. Mitotic index correlated well with radiosensitivity, and the low mitotic index caused by starvation made the tumor cell recover poorly. 4. The DNA synthetic rate measured by means of iodine labeled IUdR did not successfully correlate with the mitotic rate, presumably because of the role of thymidine pool size in this experiment. 5. The serum protein level possibly with the tumor growth, which modified the radiosensitivity. 6. Serum oxygen was difficult to interpret, however, it might be compensated by erythrocytosis in a starved condition.

  2. Synergism between two helper cell subpopulations characterized by different radiosensitivity and nylon adherence

    International Nuclear Information System (INIS)

    Agarossi, G.; Mancini, C.; Doria, G.

    1981-01-01

    The present work extends our previous results on the radiosensitivity of the helper cell function. Two helper cell subpopulations, 1 radiosensitive and the other radioresistant, have been demonstrated in the spleen of mice at different times after priming with HRBC. The radiosensitive subpopulation increases with the increasing time interval between carrier-priming and irradiation. The 2 cell subpopulations have been further characterized by different nylon adherence properties: radioresistant helper cells adhere to nylon wool, whereas radiosensitive cells pass through. The 2 cell subpopulations were separated by x-irradiation and nylon wool filtration, and their helper activity was assessed separately or after recombination. The results favor the notion that 2 functionally independent helper T cells, as characterized by different radiosensitivity and nylon adherence, participate synergistically in the helper activity of primed spleen cells

  3. Effect of radiotherapy on the immunocompetence in patients with bronchogenic carcinoma and laryngeal cancer

    International Nuclear Information System (INIS)

    Oshitani, Takashi

    1981-01-01

    We evaluated the immunocompetence of 80 patients with bronchogenic carcinoma and 17 patients with laryngeal cancer undergoing radiotherapy, using collectively many types of immunological parameters. In patients with bronchogenic carcinoma, no significant difference was seen with PHA and PPD skin tests, but the reactivity of PHA skin tests gradually decreased in the course of treatment. It was assumed that radiotherapy might not interfere with the recognition of antigen. Lymphocyte blastoid transformations with PHA, Con A and PWM were all inhibited significantly. Since these three mitogens can stimulate the different groups of lymphocyte, the inhibition to the proliferative function of lymphocyte due to radiotherapy would seem to cover a wide area, including T and B lymphocyte. Concerning the comparative radiosensitivity of T and B lymphocyte, no significant result was obtained. However, in the dose of 20Gy the percentage of T lymphocyte decreased, while the percentage of B lymphocyte increased. The percentage of early rosetts, one subset of T cell, decreased more sensitively than that of T cell, but there was no significant difference. Immunocompetence of cases in stage III, which was significantly high before treatment, decreased to the same level as those in stage IV according to the treatment. In patients with laryngeal cancer, lymphocyte counts and reactivity of PHA skin tests were not influenced by radiotherapy, and then reactivity of PPD skin tests and lymphocyte blastoid transformations with PHA and Con A tended to increase instead. (J.P.N.)

  4. DNA-PK. The major target for wortmannin-mediated radiosensitization by the inhibition of DSB repair via NHEJ pathway

    International Nuclear Information System (INIS)

    Hashimoto, Mitsumasa; Rao, S.; Tokuno, Osamu; Utsumi, Hiroshi; Takeda, Shunichi

    2003-01-01

    The effect of wortmannin posttreatment was studied in cells derived from different species (hamster, mouse, chicken, and human) with normal and defective DNA-dependent protein kinase (DNA-PK) activity, cells with and without the ataxia telangiectasia mutated (ATM) gene, and cells lacking other regulatory proteins involved in the DNA double-strand break (DSB) repair pathways. Clonogenic assays were used to obtain all results. Wortmannin radiosensitization was observed in Chinese hamster cells (V79-B310H, CHO-K1), mouse mammary carcinoma cells (SR-1), transformed human fibroblast (N2KYSV), chicken B lymphocyte wild-type cells (DT40), and chicken Rad54 knockout cells (Rad54 -/- ). However, mouse mammary carcinoma cells (SX9) with defects in the DNA-PK and chicken DNA-PK catalytic subunit (DNA-PKcs) knockout cells (DNA-PKcs -/-/- ) failed to exhibit wortmannin radiosensitization. On the other hand, severe combined immunodeficiency (SCID) mouse cells (SC3VA2) exposed to wortmannin exhibited significant increases in radiosensitivity, possibly because of some residual function of DNA-PKcs. Moreover, the transformed human cells derived from AT patients (AT2KYSV) and chicken ATM knockout cells (ATM -/- ) showed pronounced wortmannin radiosensitization. These studies demonstrate confirm that the mechanism underlying wortmannin radiosensitization is the inhibition of DNA-PK, but not of ATM, thereby resulting in the inhibition of DSB repair via nonhomologous endjoining (NHEJ). (author)

  5. Bacterial radiosensitivity to gamma and ultraviolet. Compositional dependence and repair mechanisms

    International Nuclear Information System (INIS)

    Saez Angulo, R. M.; Davila, C. A.

    1974-01-01

    The gamma and ultraviolet radiosensitivity of several species of bacteria has been determined its dependence on DNAs composition and repair processes has been studied. Base composition are evaluated by chromatography, DNA melting temperature and isopycnic sedimentation on CsCl gradient. Repair capacity of gamma -and UV- lesions has been studied in two bacterial strains with same DMA base composition. It is concluded that the postulated correlation between radiosensitivity and base composition can not be generalized, the enzymatic repair mechanisms being of determining on radiosensitivity. (Author) 248 refs

  6. Distribution of Proliferating Bone Marrow in Adult Cancer Patients Determined Using FLT-PET Imaging

    International Nuclear Information System (INIS)

    Hayman, James A.; Callahan, Jason W.; Herschtal, Alan; Everitt, Sarah; Binns, David S.; Hicks, Rod J.; Mac Manus, Michael

    2011-01-01

    Purpose: Given that proliferating hematopoietic stem cells are especially radiosensitive, the bone marrow is a potential organ at risk, particularly with the use of concurrent chemotherapy and radiotherapy. Existing data on bone marrow distribution have been determined from the weight and visual appearance of the marrow in cadavers. 18 F-fluoro-L-deoxythymidine concentrates in bone marrow, and we used its intensity on positron emission tomography imaging to quantify the location of the proliferating bone marrow. Methods and Materials: The 18 F-fluoro-L-deoxythymidine positron emission/computed tomography scans performed at the Peter MacCallum Cancer Centre between 2006 and 2009 on adult cancer patients were analyzed. At a minimum, the scans included the mid-skull through the proximal femurs. A software program developed at our institution was used to calculate the percentage of administered activity in 11 separately defined bony regions. Results: The study population consisted of 13 patients, 6 of whom were men. Their median age was 61 years. Of the 13 patients, 9 had lung cancer, 2 had colon cancer, and 1 each had melanoma and leiomyosarcoma; 6 had received previous, but not recent, chemotherapy. The mean percentage of proliferating bone marrow by anatomic site was 2.9% ± 2.1% at the skull, 1.9% ± 1.2% at the proximal humeri, 2.9% ± 1.3% at the sternum, 8.8% ± 4.7% at the ribs and clavicles, 3.8% ± 0.9% at the scapulas, 4.3% ± 1.6% at the cervical spine, 19.9% ± 2.6% at the thoracic spine, 16.6% ± 2.2% at the lumbar spine, 9.2% ± 2.3% at the sacrum, 25.3% ± 4.9% at the pelvis, and 4.5% ± 2.5% at the proximal femurs. Conclusion: Our modern estimates of bone marrow distribution in actual cancer patients using molecular imaging of the proliferating marrow provide updated data for optimizing normal tissue sparing during external beam radiotherapy planning.

  7. Comparative quantitative studies on the radiosensitivity of the oral cavity epithelium

    International Nuclear Information System (INIS)

    Lyubenov, T.

    1986-01-01

    A series of 146 patients with miscellaneous localizations of malignant tumors in the head and neck area, in whom different portions of the oral cavity epithelium came within the field subject to irradiation were included in the study. Using the Kirk's formula for cumulative radiation effect, quantitative relationships in the manifestation of radioepithelitis were searched for. With increasing the intervals of the cumulative radiation effect, the number of patients and the number of interruptions in treatment with different localizations of the tumor depended on epithelium radiosensitivity

  8. 5-Fluorouracil modulation of radiosensitivity in cultured human carcinoma cells

    International Nuclear Information System (INIS)

    Smalley, S.R.; Kimler, B.F.; Evans, R.G.

    1991-01-01

    We evaluated conventional pulse exposure versus continuous exposure models of 5-fluorouracil (5-FU) radiosensitization in HT-29 (human colon adenocarcinoma) and DU-145 (human prostate cancer adenocarcinoma) cell lines. Cell survival following treatment with drug and/or radiation was determined by colony formation assays. Radiation was delivered either by itself, approximately midway through a 1-hr exposure to 5-FU (10 micrograms/ml), or at various times following initiation of exposure to 5-FU (0.5 microgram/ml) present throughout the entire period of incubation. Drug concentrations were selected to approximate those achieved in vivo in humans. HT-29 cells showed a plating efficiency of 87% and similar cytotoxicity (survival reduced to 0.57-0.71) for all 5-FU conditions. The Do's of the radiation survival curves were not different for 1 hr of 5-FU exposure versus radiation alone. However, continuous exposure conditions demonstrated statistically significantly different Do's from radiation alone and pulse 5-FU exposure. DU-145 cells displayed a plating efficiency of 17% and cytotoxicities of 0.10-0.91 for the 5-FU conditions. DU-145 cells showed different radiation 5-FU interactions: 5-FU produced statistically significant changes in Do well as the differences between cell lines insofar as their radiosensitization by 5-FU underscore the caution required in extrapolating these radiobiologic models to the clinical setting

  9. Membrane specific drugs as radiosensitizers

    Energy Technology Data Exchange (ETDEWEB)

    George, K.C.; Mishra, K.P.; Shenoy, M.A.; Singh, B.B.; Srinivasan, V.T.; Verma, N.C.

    1981-01-01

    Procaine, paracetamol, and chlorpromazine showed inhibition of post irradiation repair. The chlorpromazie effect could be further augmented by treatment of cells with procaine. Chlorpromazine was also found to be preferentially toxic to hypoxid bacterial cells, and the survivors showed extreme radiosensitivity to gamma rays. Chlorpromazine was found to inhibit tumour growth in swiss mice when given intraperitoneally as well as when injected directly into the tumour. When combined with single x-ray doses, significant radiosensitization was observed in two in vivo tumours sarcoma 180A and fibrosarcoma. These results indicated that chlorpromazine may prove a good drug for combined chemo-radiotherapy of solid tumours. Investigations continued studying various aspects such as effectiveness in other tumour lines, distribution in healthy and tumour bearing animals, hyperthermia and drug combination effects, and encapsulation of the drug in artificial liposomes and blood cells. (ERB)

  10. Knockdown of AMPKα decreases ATM expression and increases radiosensitivity under hypoxia and nutrient starvation in an SV40-transformed human fibroblast cell line, LM217.

    Science.gov (United States)

    Murata, Yasuhiko; Hashimoto, Takuma; Urushihara, Yusuke; Shiga, Soichiro; Takeda, Kazuya; Jingu, Keiichi; Hosoi, Yoshio

    2018-01-22

    Presence of unperfused regions containing cells under hypoxia and nutrient starvation contributes to radioresistance in solid human tumors. It is well known that hypoxia causes cellular radioresistance, but little is known about the effects of nutrient starvation on radiosensitivity. We have reported that nutrient starvation induced decrease of mTORC1 activity and decrease of radiosensitivity in an SV40-transformed human fibroblast cell line, LM217, and that nutrient starvation induced increase of mTORC1 activity and increase of radiosensitivity in human liver cancer cell lines, HepG2 and HuH6 (Murata et al., BBRC 2015). Knockdown of mTOR using small interfering RNA (siRNA) for mTOR suppressed radiosensitivity under nutrient starvation alone in HepG2 cells, which suggests that mTORC1 pathway regulates radiosensitivity under nutrient starvation alone. In the present study, effects of hypoxia and nutrient starvation on radiosensitivity were investigated using the same cell lines. LM217 and HepG2 cells were used to examine the effects of hypoxia and nutrient starvation on cellular radiosensitivity, mTORC1 pathway including AMPK, ATM, and HIF-1α, which are known as regulators of mTORC1 activity, and glycogen storage, which is induced by HIF-1 and HIF-2 under hypoxia and promotes cell survival. Under hypoxia and nutrient starvation, AMPK activity and ATM expression were increased in LM217 cells and decreased in HepG2 cells compared with AMPK activity under nutrient starvation alone or ATM expression under hypoxia alone. Under hypoxia and nutrient starvation, radiosensitivity was decreased in LM217 cells and increased in HepG2 cells compared with radiosensitivity under hypoxia alone. Under hypoxia and nutrient starvation, knockdown of AMPK decreased ATM activity and increased radiation sensitivity in LM217 cells. In both cell lines, mTORC1 activity was decreased under hypoxia and nutrient starvation. Under hypoxia alone, knockdown of mTOR slightly increased ATM

  11. Radiosensitization of mouse spermatogenic stem cells by Ro-07-0582

    International Nuclear Information System (INIS)

    Suzuki, N.; Withers, R.; Hunter, N.

    1977-01-01

    The hypoxic character of the spermatogenic stem cells of the mouse testis was investigated by measuring the effect on radiosensitivity of treatment with the hypoxic cell radiosensitizer, Ro-07-0582 or hyperbaric oxygen (30 psi). The D 0 values obtained were 181 (161-207) rad for irradiation alone, 140 (133-148) rad for irradiation after treatment with Ro-07-0582, and about 100 rad for irradiation in the presence of hyperbaric oxygen. Ro-07-0582 alone was slightly cytotoxic. The results demonstrate that mouse spermatogenic stem cells are radiosensitized by Ro-07-0582 or hyperbaric oxygen and are not as well oxygenated as other normal tissues

  12. Selective in vivo radiosensitization by 5-fluorocytosine of human colorectal carcinoma cells transduced with the E. coli cytosine deaminase (CD) gene

    International Nuclear Information System (INIS)

    Gabel, M.; Kim, J.H.; Kolozsvary, A.; Khil, M.; Freytag, S.

    1998-01-01

    Purpose: The E. coli cytosine deaminase (CD) gene encodes an enzyme capable of converting the nontoxic prodrug 5-fluorocytosine (5-FC) to 5-fluorouracil (5-FU), a known radiosensitizer. Having previously shown that combined CD suicide gene therapy and radiation (RT) results in pronounced radiosensitization in vitro, we progressed to in vivo studies of combined therapy. Methods and Materials: WiDr human colon cancer cells were transduced in vitro with the CD gene and cells expressing CD were selected for use as xenografts in a nude mouse model. After administration of 5-FC, tumors received 10-30 Gy local field radiation (RT) and tumor growth delay was compared to control animals receiving either 5-FU, 5-FC, or RT alone. Results: Maximal growth delay was seen in mice treated with 5-FC for 6 consecutive days prior to RT. Combined treatment with 15 Gy radiation resulted in a dose-modifying factor (DMF) of 1.50, and a greater DMF was observed with higher doses of radiation. There was no appreciable toxicity using this new approach. In contrast, a similar treatment of combined 5-FU and radiation resulted in considerable toxicity and no appreciable radiosensitization. Conclusion: The present results show that combined suicide gene therapy and RT results in pronounced antitumor effect without any notable toxicity. This indicates that the CD gene may be useful in the development of novel treatment strategies combining radiation and gene therapy in the treatment of locally advanced cancers

  13. Radioprotection of IDH1-Mutated Cancer Cells by the IDH1-Mutant Inhibitor AGI-5198.

    Science.gov (United States)

    Molenaar, Remco J; Botman, Dennis; Smits, Myrthe A; Hira, Vashendriya V; van Lith, Sanne A; Stap, Jan; Henneman, Peter; Khurshed, Mohammed; Lenting, Krissie; Mul, Adri N; Dimitrakopoulou, Dionysia; van Drunen, Cornelis M; Hoebe, Ron A; Radivoyevitch, Tomas; Wilmink, Johanna W; Maciejewski, Jaroslaw P; Vandertop, W Peter; Leenders, William P; Bleeker, Fonnet E; van Noorden, Cornelis J

    2015-11-15

    Isocitrate dehydrogenase 1 (IDH1) is mutated in various types of human cancer to IDH1(R132H), a structural alteration that leads to catalysis of α-ketoglutarate to the oncometabolite D-2-hydroxyglutarate. In this study, we present evidence that small-molecule inhibitors of IDH1(R132H) that are being developed for cancer therapy may pose risks with coadministration of radiotherapy. Cancer cells heterozygous for the IDH1(R132H) mutation exhibited less IDH-mediated production of NADPH, such that after exposure to ionizing radiation (IR), there were higher levels of reactive oxygen species, DNA double-strand breaks, and cell death compared with IDH1 wild-type cells. These effects were reversed by the IDH1(R132H) inhibitor AGI-5198. Exposure of IDH1 wild-type cells to D-2-hydroxyglutarate was sufficient to reduce IDH-mediated NADPH production and increase IR sensitivity. Mechanistic investigations revealed that the radiosensitivity of heterozygous cells was independent of the well-described DNA hypermethylation phenotype in IDH1-mutated cancers. Thus, our results argue that altered oxidative stress responses are a plausible mechanism to understand the radiosensitivity of IDH1-mutated cancer cells. Further, they offer an explanation for the relatively longer survival of patients with IDH1-mutated tumors, and they imply that administration of IDH1(R132H) inhibitors in these patients may limit irradiation efficacy in this setting. ©2015 American Association for Cancer Research.

  14. Radiogenic male breast cancer with in vitro sensitivity to ionizing radiation and bleomycin

    International Nuclear Information System (INIS)

    Greene, M.H.; Goedert, J.J.; Bech-Hansen, N.T.; McGuire, D.; Paterson, M.C.; Fraumeni, J.F. Jr.

    1983-01-01

    A cytogenetically normal man with gynecomastia and a family history of diverse cancers developed adenocarcinoma of the breast 30 years following thymic irradiation. In vitro experiments measuring colony-forming ability of cultured skin fibroblasts from family members implied that the patient had a small but significant increase in sensitivity to ionizing radiation, and a moderate increase in sensitivity to bleomycin, a radiomimetic drug. Enhanced radiosensitivity of fibroblasts from the patient's mother, and bleomycin sensitivity of fibroblasts from the sister suggested, but did not prove, that genetic susceptibility affected the risk of radiogenic cancer in this individual. In vitro studies of cancer-prone kindreds are a useful research strategy in delineating mechanisms of carcinogenesis

  15. Melanoma cells show a heterogeneous range of sensitivity to ionizing radiation and are radiosensitized by inhibition of B-RAF with PLX-4032

    International Nuclear Information System (INIS)

    Sambade, Maria J.; Peters, Eldon C.; Thomas, Nancy E.; Kaufmann, William K.; Kimple, Randall J.; Shields, Janiel M.

    2011-01-01

    Purpose: To assess the relative radiosensitivities of a large collection of melanoma cell lines and to determine whether pharmacologic inhibition of mutant B-RAF with PLX-4032 can radiosensitize B-Raf+ melanoma cells. Materials and methods: A large collection of melanoma cell lines (n = 37) were treated with 0-8 Gy IR and clonogenic survival assays used to generate survival curves to rank relative radiosensitivities among the cell lines. The ability of a B-RAF inhibitor, PLX-4032, to radiosensitize highly radioresistant B-Raf+ cells was also assessed by clonogenic cell survival and spheroid invasion assays and the effects of treatment on the cell cycle assessed by FACS. Results: Melanoma cell lines displayed a very large, heterogeneous range of SF2 values (1.002-0.053) with a mean of 0.51. Cell lines with surviving fractions of 0.29 or less at SF2 and SF4 were observed at a high frequency of 18.9% and 70.2%, respectively. Treatment of B-Raf+ cells with the B-RAF inhibitor PLX-4032 in combination with radiation provided enhanced inhibition of both colony formation and invasion, and radiosensitized cells through an increase in G 1 arrest. Conclusions: Our data suggest that melanomas are not uniformly radioresistant with a significant subset displaying inherent radiosensitivity. Pharmacologic inhibition of B-RAF with PLX-4032 effectively radiosensitized B-Raf+ melanoma cells suggesting that this combination approach could provide improved radiotherapeutic response in B-Raf+ melanoma patients.

  16. Study on ionizing radiosensitivity of respiratory deficiency yeast mutants

    International Nuclear Information System (INIS)

    Mao Shuhong; Chinese Academy of Sciences, Beijing; Jin Genming; Wei Zengquan; Xie Hongmei

    2006-01-01

    The radiosensitivity of respiratory deficiency yeast mutants has been studied in this work. The mutants which were screened from the yeasts after ionizing irradiation were irradiated with 12 C 6+ at different doses. Because of the great change in its mitochondria and mitochondrial DNA, the respiratory deficiency yeast mutants show radio-sensitivity at dose less than 1 Gy and radioresistance at doses higher than 1 Gy. (authors)

  17. Analysis of the factors in determining radiosensitivity in mammalian cells by using radio-sensitive and -resistant clones isolated from HeLa S3 cells in vitro

    International Nuclear Information System (INIS)

    Nikaido, Osamu; Horikawa, Masakatsu

    1976-01-01

    The factors in determining radiosensitivity of cultured mammalian cells were analysed by using two clones each having different radiosensitivities. The radiosensitive clones were isolated from HeLa S3 cells by the N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-treatment, X-irradiation (200 R) and 5-bromodeoxyuridine (BUdR)-visible light method. On the other hand, the radioresistant clone was isolated by single X-irradiation (2000 R) from MNNG-treated HeLa S3 cell population. The radiosensitivities expressed in D sub(o) and D sub(q) values were 110 and 140 R in radiosensitive SM-1a clone and 180 and 230 R in radioresistant RM-1b clone respectively. The biological and biochemical characteristics of both clones such as the distribution of chromosome numbers, formation and rejoining of single strand breaks in DNA caused by X-irradiation, non-protein sulfhydryl (NPSH) and apparent total sulfhydryl (APSH) contents were measured. Among the characteristics analysed, different contents of NPSH in the cell were well correlated to their daiosensitivities among the original HeLa S3 cells, SM-1a and RM-1b clone. Additionally, it was found that the radioresistant L.P3 Co-3 cells isolated by Tsuboi et al. from the original mouse L.P3 cells by means of serial irradiation with 60 Co γ-rays have more abundant NPSH than the original L.P3 cells. From these results, it can be concluded that the amount of NPSH play the main role in determining radiosensitivity in cultured mammalian cells. (auth.)

  18. Clonal cell populations unresponsive to radiosensitization induced by telomerase inhibition

    International Nuclear Information System (INIS)

    Ju, Yeun-Jin; Shin, Hyun-Jin; Park, Jeong-Eun; Juhn, Kyoung-Mi; Woo, Seon Rang; Kim, Hee-Young; Han, Young-Hoon; Hwang, Sang-Gu; Hong, Sung-Hee; Kang, Chang-Mo; Yoo, Young-Do; Park, Won-Bong; Cho, Myung-Haing; Park, Gil Hong; Lee, Kee-Ho

    2010-01-01

    Research highlights: → In our present manuscript, we have clearly showed an interesting but problematic obstacle of a radiosensitization strategy based on telomerase inhibition by showing that: Clonal population unresponsive to this radiosensitization occasionally arise. → The telomere length of unsensitized clones was reduced, as was that of most sensitized clones. → The unsensitized clones did not show chromosome end fusion which was noted in all sensitized clones. → P53 status is not associated with the occurrence of unsensitized clone. → Telomere end capping in unsensitized clone is operative even under telomerase deficiency. -- Abstract: A combination of a radiotherapeutic regimen with telomerase inhibition is valuable when tumor cells are to be sensitized to radiation. Here, we describe cell clones unresponsive to radiosensitization after telomere shortening. After extensive division of individual transformed clones of mTERC -/- cells, about 22% of clones were unresponsive to radiosensitization even though telomerase action was inhibited. The telomere lengths of unsensitized mTERC -/- clones were reduced, as were those of most sensitized clones. However, the unsensitized clones did not exhibit chromosomal end-to-end fusion to the extent noted in all sensitized clones. Thus, a defense mechanism preventing telomere erosion is operative even when telomeres become shorter under conditions of telomerase deficiency, and results in unresponsiveness to the radiosensitization generally mediated by telomere shortening.

  19. Distant Metastasis Risk Stratification for Patients Undergoing Curative Resection Followed by Adjuvant Chemoradiation for Extrahepatic Bile Duct Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyubo [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Chie, Eui Kyu, E-mail: ekchie93@snu.ac.kr [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Jang, Jin-Young; Kim, Sun Whe [Department of Surgery, Seoul National University College of Medicine, Seoul (Korea, Republic of); Han, Sae-Won; Oh, Do-Youn; Im, Seock-Ah; Kim, Tae-You; Bang, Yung-Jue [Department of Internal Medicine, Seoul National University College of Medicine, Seoul (Korea, Republic of); Ha, Sung W. [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Institute of Radiation Medicine, Medical Research Center, Seoul National University (Korea, Republic of)

    2012-09-01

    Purpose: To analyze the prognostic factors predicting distant metastasis in patients undergoing adjuvant chemoradiation for extrahepatic bile duct (EHBD) cancer. Methods and Materials: Between January 1995 and August 2006, 166 patients with EHBD cancer underwent resection with curative intent, followed by adjuvant chemoradiation. There were 120 males and 46 females, and median age was 61 years (range, 34-86). Postoperative radiotherapy was delivered to tumor bed and regional lymph nodes (median dose, 40 Gy; range, 34-56 Gy). A total of 157 patients also received fluoropyrimidine chemotherapy as a radiosensitizer, and fluoropyrimidine-based maintenance chemotherapy was administered to 127 patients. Median follow-up duration was 29 months. Results: The treatment failed for 97 patients, and the major pattern of failure was distant metastasis (76 patients, 78.4%). The 5-year distant metastasis-free survival rate was 49.4%. The most common site of distant failure was the liver (n = 36). On multivariate analysis, hilar tumor, tumor size {>=}2 cm, involved lymph node, and poorly differentiated tumor were associated with inferior distant metastasis-free survival (p = 0.0348, 0.0754, 0.0009, and 0.0078, respectively), whereas T stage was not (p = 0.8081). When patients were divided into four groups based on these risk factors, the 5-year distant metastasis-free survival rates for patients with 0, 1, 2, and 3 risk factors were 86.4%, 59.9%, 32.5%, and 0%, respectively (p < 0.0001). Conclusion: Despite maintenance chemotherapy, distant metastasis was the major pattern of failure in patients undergoing adjuvant chemoradiation for EHBD cancer after resection with curative intent. Intensified chemotherapy is warranted to improve the treatment outcome, especially in those with multiple risk factors.

  20. Radiosensitivity and TP 53, EGFR amplification and LOH10 analysis of primary glioma cell cultures

    International Nuclear Information System (INIS)

    Gerlach, B.; Harder, A.H.; Slotman, B.J.; Sminia, P.; Hulsebos, T.J.M.; Leenstra, S.; Peter Vandertop, W.; Hartmann, K.A.

    2002-01-01

    Aim: Determination of in-vitro radiosensitivity and genetic alterations of cell cultures derived from human glioma biopsy tissue and established glioma cell lines. Material and Methods: Fresh brain tumor specimens of six patients were processed to early passage cell cultures. In addition the cell lines D 384 and Gli 6 were used. Cell cultures were irradiated with doses from 2 to 10 Gy. Following irradiation, cell survival was determined by clonogenic assay and survival curves were generated. The surviving fractions after 2 Gy (SF2) and 4 Gy (SF4) were used as radiosensitivity parameters. Genetic analysis included determination of the mutational and loss of heterozygosity (LOH) status of TP 53 (exons 5-8), the LOH 10- and epidermal growth factor receptor gene (EGFR) amplification status. Results: The SF2 and SF4 values ranged from 0.54 to 0.88 (mean: 0.70) and from 0.13 to 0.52 (mean: 0.32), respectively. Genetic alterations were found in the Gli 6 cell line and in two primary cell cultures. The genetic profile of Gli 6 showed LOH but no TP 53 mutation, complete LOH 10 and no EGFR amplification. The VU 15 cell culture showed TP 53 mutation but no LOH 10 or EGFR amplification, while VU 24 showed incomplete LOH 10, EGFR amplification and no TP 53 mutation. In the other four cell cultures and D 384 cell line no genetic alterations were diagnosed. Histopathological classification of glioblastoma multiforme and/or genetic alterations resulted in lower radiosensitivity. Conclusion: In this small series of early passage glioma cell cultures low radiosensitivity and alterations in cell regulatory genes were seen. Further testing of biological behavior in larger series of patient-derived material is ongoing. (orig.)

  1. Influence of the 100% w/v perfluorooctyl bromide (PFOB) emulsion dose on tumour radiosensitivity

    International Nuclear Information System (INIS)

    Thomas, C.; Guichard, M.; Riess, J.

    1991-01-01

    The radiosensitizing effect of a 100% w/v emulsion of a fluuorocarbon PFOB, which carries 4 times more oxygen than Fluosol-DA 20% emulsion, was studied on two human tumour xenografts (HRT18 and HT29) and murine tumour EMT6. This effect was compared to that of carbogen alone. The fluorocrit (amount of fluorocarbon in the blood) and haematocrit remained unchanged from 7 to 65 min post-injection of the emulsion (8ml/kg). Significant tumour radiosensitization was obtained with relatively low amounts of 100% w/v concentrated emulsion of PFOB plus carbogen. Maximum radiosensitization occurs at low fluorocarbon dose of about 3g/kg. These results are comparable to those obtained with Fluosol-DA 20% or Therox emulsion. Since this radiosensitization occurs only at relatively low fluorocrit without haematocrit modification, the oxygen-carrying capacity of the fluorocarbon is not the only factor involved in radiosensitization of tumor cells, regardless of the effect of carbogen on radiosensitivity. (author)

  2. Radiosensitization of hypoxic tumor cells in vitro by nitric oxide

    International Nuclear Information System (INIS)

    Griffin, Robert J.; Makepeace, Carol M.; Hur, Won-Joo; Song, Chang W.

    1996-01-01

    Purpose: The effects of nitric oxide (NO) on the radiosensitivity of SCK tumor cells in oxic and hypoxic environments in vitro were studied. Methods and Materials: NO was delivered to cell suspensions using the NO donors 2,2-diethyl-1-nitroso-oxyhydrazine sodium salt (DEA/NO), and a spermine/nitric oxide complex (SPER/NO), which release NO at half-lives of 2.1 min and 39 min at pH 7.4, respectively. The cells were suspended in media containing DEA/NO or SPER/NO for varying lengths of time under oxic or hypoxic conditions, irradiated, and the clonogenicity determined. Results: Both compounds markedly radiosensitized the hypoxic cells. The drug enhancement ratios (DER) for 0.1, 1.0, and 2.0 mM DEA/NO were 2.0, 2.3 and 3.0, respectively, and those for 0.1, 1.0, and 2.0 mM SPER/NO were 1.6, 2.3, and 2.8, respectively. Aerobic cells were not radiosensitized by DEA/NO or SPER/NO. When DEA/NO and SPER/NO were incubated in solution overnight to allow release of NO, they were found to have no radiosensitizing effect under hypoxic or oxic conditions indicating the sensitization by the NO donors was due to the NO molecule released from these drugs. At the higher concentrations, SPER/NO was found to be cytotoxic in aerobic conditions but not in hypoxic conditions. DEA/NO was only slightly toxic to the cells in both aerobic and hypoxic conditions. Conclusions: NO released from NO donors DEA/NO and SPER/NO is as effective as oxygen to radiosensitize hypoxic cells in vitro. Its application to the radiosensitization of hypoxic cells in solid tumors remains to be investigated

  3. Up-regulation of integrin β3 in radioresistant pancreatic cancer impairs adenovirus-mediated gene therapy

    International Nuclear Information System (INIS)

    Egami, Takuya; Ohuchida, Kenoki; Yasui, Takaharu; Onimaru, Manabu; Toma, Hiroki; Sato, Norihiro; Tanaka, Masao; Mizumoto, Kazuhiro; Matsumoto, Kunio

    2009-01-01

    Adenovirus-mediated gene therapy is a promising approach for the treatment of pancreatic cancer. We previously reported that radiation enhanced adenovirus-mediated gene expression in pancreatic cancer, suggesting that adenoviral gene therapy might be more effective in radioresistant pancreatic cancer cells. In the present study, we compared the transduction efficiency of adenovirus-delivered genes in radiosensitive and radioresistant cells, and investigated the underlying mechanisms. We used an adenovirus expressing the hepatocyte growth factor antagonist, NK4 (Ad-NK4), as a representative gene therapy. We established two radioresistant human pancreatic cancer cell lines using fractionated irradiation. Radiosensitive and radioresistant pancreatic cancer cells were infected with Ad-NK4, and NK4 levels in the cells were measured. In order to investigate the mechanisms responsible for the differences in the transduction efficiency between these cells, we measured expression of the genes mediating adenovirus infection and endocytosis. The results revealed that NK4 levels in radioresistant cells were significantly lower (P<0.01) than those in radiosensitive cells, although there were no significant differences in adenovirus uptake between radiosensitive cells and radioresistant cells. Integrin β3 was up-regulated and the Coxsackie virus and adenovirus receptor was down-regulated in radioresistant cells, and inhibition of integrin β3 promoted adenovirus gene transfer. These results suggest that inhibition of integrin β3 in radioresistant pancreatic cancer cells could enhance adenovirus-mediated gene therapy. (author)

  4. Reaction between nitracrine and glutathione: implications for hypoxic cell radiosensitization and cytotoxicity

    International Nuclear Information System (INIS)

    Wilson, W.R.; Anderson, R.F.

    1989-01-01

    Nitracrine (NC) is an electron affinic DNA intercalating agent and a potent hypoxia-selective cytotoxin and radiosensitizer in cell culture. Although NC is too cytotoxic and too rapidly metabolized to provide hypoxic cell radiosensitization in tumors, it is of mechanistic interest as an example of a DNA affinic radiosensitizer. We have observed a rapid chemical reaction between NC and reduced glutathione (GSH), which suggests that the observed potent in vitro cytotoxicity and radiosensitization might be dependent on thiol depletion by the large extracellular reservoir of drug. However, no GSH depletion was observed under conditions providing radiosensitization or rapid cell killing, and prior depletion of GSH by buthionine sulphoximine had no effect on cytotoxicity or formation of macromolecular adducts. Further, the intracellular reaction of NC with GSH is slower than predicted on the basis of the measured second order rate constant and the total intracellular concentrations of both species. The results are consistent with a role for DNA binding in protecting NC from reaction with GSH, and in improving the efficiency with which reduced electrophilic metabolites react with DNA in preference to GSH

  5. In vitro studies on radiosensitization effect of glucose capped gold nanoparticles in photon and ion irradiation of HeLa cells

    International Nuclear Information System (INIS)

    Kaur, Harminder; Pujari, Geetanjali; Semwal, Manoj K.; Sarma, Asitikantha; Avasthi, Devesh Kumar

    2013-01-01

    Highlights: ► Glucose capped gold nanoparticles (Glu-AuNPs) are synthesized for internalization in HeLa cells (cervical cancer cells). ► Internalization of Glu-AuNPs in HeLa cells is confirmed by cross section TEM of cells. ► Irradiation (by C ion or γ-rays) of HeLa cells with internalized Glu-AuNPs results in enhanced radiosensitization. ► There is about 30% reduction in radiation dose for 90% cell killing of HeLa cells, when internalized by Glu-AuNPs. ► The enhanced radiosensitization due to Glu-AuNPs is of interest for researchers in nanobiotechnology and radiation biology. -- Abstract: Noble metal nanoparticles are of great interest due to their potential applications in diagnostics and therapeutics. In the present work, we synthesized glucose capped gold nanoparticle (Glu-AuNP) for internalization in the HeLa cell line (human cervix cancer cells). The capping of glucose on Au nanoparticle was confirmed by Raman spectroscopy. The Glu-AuNP did not show any toxicity to the HeLa cell. The γ-radiation and carbon ion irradiation of HeLa cell with and without Glu-AuNP were performed to evaluate radiosensitization effects. The study revealed a significant reduction in radiation dose for killing the HeLa cells with internalized Glu-AuNPs as compared to the HeLa cells without Glu-AuNP. The Glu-AuNP treatment resulted in enhancement of radiation effect as evident from increase in relative biological effectiveness (RBE) values for carbon ion irradiated HeLa cells

  6. The transcriptional regulator gene E2 of the Human Papillomavirus (HPV) 16 influences the radiosensitivity of cervical keratinocytes

    International Nuclear Information System (INIS)

    Lindel, Katja; Rieken, Stefan; Daffinger, Sigrid; Weber, Klaus J; Villiers, Ethel-Michele de; Debus, Jürgen

    2012-01-01

    Clinical studies have demonstrated that HPV induced tumors constitute a specific subclass of cancer with a better response to radiation treatment. The purpose of this study was to investigate meaning of viral E2-gene for radiosensitivity. W12 cells contain episomal HPV 16 genomes, whereas S12 cells, which derive from the W12 line, contain HPV DNA as integrated copies. Clonogenic survival was analyzed using 96-well in vitro test. Using flow cytometry cell cycle analyses were performed. Expression of pRb and p53 were analyzed using intracellular staining. W12 cells (intact E2 gene) showed a lower survival fraction than S12 cells. W12 cells developed a G2/M block 24 h after irradiation with 2 Gy whereas S12 showed no G2/M bloc. After irradiation S12 cells developed polyploidy and pRb-positive cells decreased. W12 cells showed no change of pRb-positive cells. Depending on E2 gene status differences in cell cycle regulation might cause radioresistance. The E2/E7/pRb pathway seems to influence HPV-induced radiosensitivity. Our experiments demonstrated an effect of HPV on radiosensitivity of cervical keratinocytes via viral transcription regulator E2 pathway

  7. Sensing radiosensitivity of human epidermal stem cells

    International Nuclear Information System (INIS)

    Rachidi, Walid; Harfourche, Ghida; Lemaitre, Gilles; Amiot, Franck; Vaigot, Pierre; Martin, Michele T.

    2007-01-01

    Purpose: Radiosensitivity of stem cells is a matter of debate. For mouse somatic stem cells, both radiosensitive and radioresistant stem cells have been described. By contrast, the response of human stem cells to radiation has been poorly studied. As epidermis is a radiosensitive tissue, we evaluated in the present work the radiosensitivity of cell populations enriched for epithelial stem cells of human epidermis. Methods and materials: The total keratinocyte population was enzymatically isolated from normal human skin. We used flow cytometry and antibodies against cell surface markers to isolate basal cell populations from human foreskin. Cell survival was measured after a dose of 2 Gy with the XTT assay at 72 h after exposure and with a clonogenic assay at 2 weeks. Transcriptome analysis using oligonucleotide microarrays was performed to assess the genomic cell responses to radiation. Results: Cell sorting based on two membrane proteins, α6 integrin and the transferrin receptor CD71, allowed isolation of keratinocyte populations enriched for the two types of cells found in the basal layer of epidermis: stem cells and progenitors. Both the XTT assay and the clonogenic assay showed that the stem cells were radioresistant whereas the progenitors were radiosensitive. We made the hypothesis that upstream DNA damage signalling might be different in the stem cells and used microarray technology to test this hypothesis. The stem cells exhibited a much more reduced gene response to a dose of 2 Gy than the progenitors, as we found that 6% of the spotted genes were regulated in the stem cells and 20% in the progenitors. Using Ingenuity Pathway Analysis software, we found that radiation exposure induced very specific pathways in the stem cells. The most striking responses were the repression of a network of genes involved in apoptosis and the induction of a network of cytokines and growth factors. Conclusion: These results show for the first time that keratinocyte

  8. Radiosensitivity and TP 53, EGFR amplification and LOH10 analysis of primary glioma cell cultures

    NARCIS (Netherlands)

    Gerlach, Bärbel; Harder, Anna H.; Hulsebos, Theo J. M.; Leenstra, Sieger; Slotman, Berend J.; Vandertop, W. Peter; Hartmann, Karl-Axel; Sminia, Peter

    2002-01-01

    Aim: Determination of in-vitro radiosensitivity and genetic alterations of cell cultures derived from human glioma biopsy tissue and established glioma cell lines. Material and Methods: Fresh brain tumor specimens of six patients were processed to early passage cell cultures. In addition the cell

  9. Effect of retinoic acid on the radiosensitivity of normal human oral keratinocyte

    International Nuclear Information System (INIS)

    Lee, Jean; Heo, Min Suk; Lee, Sam Sun; Oh, Sung Ook; Choi, Soon Chul; Park, Tae Won; Lee, Sul Mi; Choi, Hang Moon

    2003-01-01

    To evaluate the effect of all-trans-retinotic acid (ATRA) on the radiosensitivity of normal human oral keratinocyte (NHOK). Relative cell survival fraction including SF2 (survival fraction at 2 Gy) was calculated on the basis of colony formation assay. Data were fitted to the linear-quadratic model to establish the survival curve and calculate α and β values. Using flow cytometry at 1, 2, 3, 4, and 5 days after exposure to 2 and 10 Gy irradiation, cell cycle arrest and apoptosis were analysed. To understand the molecular mechanism of the radiosensitization of ATRA on NHOK, proteins related with apoptosis and cell cycle arrest were investigated by Western blot analysis. Treatment with ATRA resulted in a significant decrease of SF2 value for NHOK from 0.63 to 0.27, and increased α and β value, indicating that ATRA increased radiosensitivity of NHOK. ATRA increased LDH significantly, but increasing irradiation dose decreased LDH, suggesting that the radiosensitizing effect of ATRA is not directly related with increasing cell necrosis by ATRA. ATRA did not induce appotosis but increased G2 arrest after 10 Gy irradiation, implying that the increased radiosensitivity of NHOK may be due to a decrease in mitosis caused by increasing G2 arrest. ATRA inhibited the reduction of p53 at 3 days after 10 Gy irradiation and increased p21 at 1 day after 10 Gy irradiation. Further study is required to determine the precise relationship between this effect and the radiosensitizing effect of ATRA. These results suggested that ATRA increase radiosensitivity by inhibiting mitosis caused by increasing G2 arrest.

  10. In vivo radiosensitizing effect of nitroimidazole derivative KIN-804

    International Nuclear Information System (INIS)

    Tada, Takuhito; Nakajima, Toshifumi; Onoyama, Yasuto; Murayama, Chieko; Mori, Yomoyuki; Nagasawa, Hideko; Hori, Hitoshi; Inayama, Seiichi

    1994-01-01

    In vivo characteristics of 2-nitroimidazole-1-methylacetohydroxamate (KIN-804), which is a newly developed hypoxic cell radiosensitizer, are presented. The toxicity, pharmacokinetics, and radiosensitizing effect of KIN-804 were studied by in vivo experiments using C3H/He mice bearing the SCCVII tumor. Results were compared with misonidazole (MISO). LD 50 7 of KIN-804 and MISO were 3200 mg/kg and 2000 mg/kg, respectively. The peak concentration of KIN-804 in the tumor occurred 20 min after intraperitoneal injection and reached about 62% of the maximum concentration in the blood. The concentrations in brain and sciatic nerve were very low and clearance from sciatic nerve was rapid. Enhancement ratios of KIN-804 calculated using the growth delay method were 1.22, 1.50, and 1.71 at doses of 50, 100, and 200 mg/kg, respectively, compared with 1.36 for MISO at a dose of 100 mg/kg. In the TCD 50 assay, enhancement ratios at a dose of 200 mg/kg were 1.69 for KIN-804 and 1.52 for MISO, respectively. KIN-804 is a promising radiosensitizer since it shows less toxicity and higher radiosensitizing activity than MISO. 10 refs., 5 figs

  11. The measurement of intrinsic cellular radiosensitivity in human tumours and normal tissues

    International Nuclear Information System (INIS)

    Lawton, P.A.

    1995-01-01

    Human tumour and normal cell radiosensitivity are thought to be important factors determining the response of tumour and normal tissues to radiotherapy, respectively. Clonogenic assays are the standard method for measuring radiosensitivity but they are of limited applicability for clinical use with fresh human tumours. The main aim of this work was to evaluate the Adhesive Tumour Cell Culture System (ATCCS), as a method for measuring the radiosensitivity of human tumours. A soft agar clonogenic assay, the modified Courtenay-Mills assay, was used as a standard to compare with the ATCCS. The demonstration that fibroblast contamination could occur with both assay methods led to the investigation of a new technique for removing unwanted fibroblasts from tumour cell suspensions and to the use of a multiwell assay for measuring fibroblast radiosensitivity. (author)

  12. The measurement of intrinsic cellular radiosensitivity in human tumours and normal tissues

    Energy Technology Data Exchange (ETDEWEB)

    Lawton, P.A.

    1995-12-31

    Human tumour and normal cell radiosensitivity are thought to be important factors determining the response of tumour and normal tissues to radiotherapy, respectively. Clonogenic assays are the standard method for measuring radiosensitivity but they are of limited applicability for clinical use with fresh human tumours. The main aim of this work was to evaluate the Adhesive Tumour Cell Culture System (ATCCS), as a method for measuring the radiosensitivity of human tumours. A soft agar clonogenic assay, the modified Courtenay-Mills assay, was used as a standard to compare with the ATCCS. The demonstration that fibroblast contamination could occur with both assay methods led to the investigation of a new technique for removing unwanted fibroblasts from tumour cell suspensions and to the use of a multiwell assay for measuring fibroblast radiosensitivity. (author).

  13. Heterogeneity of the radiosensitivity and origins of tissue macrophage colony-forming cells

    Energy Technology Data Exchange (ETDEWEB)

    Oghiso, Yoichi; Yamada, Yutaka (National Inst. of Radiological Sciences, Chiba (Japan))

    1992-12-01

    Previous studies suggest that the radiosensitivity and origin of tissue macrophage precursors differ from those of hemopoietic macrophage colony-forming units (CFU-Ms) committed to macrophage-lineage cells. We assessed the origins of tissue macrophage colony-forming cells (M-CFCs) in mice by comparing their kinetics and radiosensitivities in the normal steady state and under the conditions of bone marrow depletion by [sup 89]Sr-administration and/or splenectomy. The results indicate that the radiosensitive peritoneal M-CFCs elicited by thioglycollate are derived from bone marrow macrophage precursors; where as alveolar M-CFCs, which are radioresistant, are self-sustained locally and independent of hemopoietic macrophage precursors. In contrast, highly radiosensitive liver M-CFCs are probably derived from CFU-Ms that appear to be propagated in the spleen in association with hemopoietic responses. (author).

  14. Radiosensitivity of the swiss-rap mouse as a function of its growth rate

    International Nuclear Information System (INIS)

    Legeay, G.; Glas, J.F.

    1969-01-01

    The results of an exhaustive study of the age dependence of the radiosensitivity of female Swiss-Rap mice are given. A close relationship of radiosensitivity versus age could not be brought out, whereas the weekly growth rate could be accurately related to radiosensitivity. Thus, the latter should be studied when a strain is to be used for biological experiments, as the rates of growth are different with the strains. (author) [fr

  15. Differential action on cancer and normal tissue by adrenochrome monoaminoguanidine methanesulfonate and cytochrome C combined with radiotherapy

    International Nuclear Information System (INIS)

    Nakatsugawa, S.; Sugahara, T.

    1994-01-01

    The possibility that radioprotective effects on potent natural killer (NK) cells by adrenochrome monoaminoguanidine methanesulfonate (AMM) + cytochrome C during radiotherapy (RT) for lung cancer might result in the radiosensitization of human lung cancer cells in vivo is examined. Human lung cancer xenografts in the right hind legs of KSN mice (10 weeks old) were locally irradiated with 20 Gy of X ray. AMM (10 mg/kg/day) and/or cytochrome C (CCC) (5 mg/kg/day) were given intraperitoneally immediately before or after RT, followed by daily administration for 4 days. Natural killer activities of host splenocytes were also tested with the standard 51 Cr releasing assay with YAC-1 cells as target cells. In a clinical study, 65 patients with lung cancer were treated with more than 50 Gy of RT with or without combination with AMM + CCC, OK-432 or AMM + CCC + OK-432. Before and after RT, lymphocyte subsets in the peripheral blood were examined with dichromatic analysis using an Ortho Spectrum IIIFCM system and fluorescent MABs. In this study, the change in the absolute number of each subset was investigated. AMM + cytochrome C augumented NK activity in KSN nude mice, protected potent NK cells in patients with lung cancer against RT and sensitized the human lung cancer xenografts to RT. AMM + cytochrome C may have potential as a differential modulator of radiosensitivity of normal tissues and of tumors. 8 refs., 2 figs., 1 tab

  16. Radiosensitivity of continuous cultures: experiments with diploid yeast

    International Nuclear Information System (INIS)

    Kiefer, J.; Wagner, E.

    1975-01-01

    To study the influence of systems parameters on the radiosensitivity of cell populations, stationary chemostat cultures of diploid yeast with different dilution rates were γ-irradiated. Proliferation and budding kinetics were investigated and the doses necessary to eliminate the entire population determined as a function of dilution rate. It was found that this killing dose decreases with dilution rate in a linear manner. The radiosensitivity of the cells was shown to depend on the dilution rate which is presumably due to differing compositions of the population. (U.S.)

  17. Celecoxib Induced Tumor Cell Radiosensitization by Inhibiting Radiation Induced Nuclear EGFR Transport and DNA-Repair: A COX-2 Independent Mechanism

    International Nuclear Information System (INIS)

    Dittmann, Klaus H.; Mayer, Claus; Ohneseit, Petra A.; Raju, Uma; Andratschke, Nickolaus H.; Milas, Luka; Rodemann, H. Peter

    2008-01-01

    Purpose: The purpose of the study was to elucidate the molecular mechanisms mediating radiosensitization of human tumor cells by the selective cyclooxygenase (COX)-2 inhibitor celecoxib. Methods and Materials: Experiments were performed using bronchial carcinoma cells A549, transformed fibroblasts HH4dd, the FaDu head-and-neck tumor cells, the colon carcinoma cells HCT116, and normal fibroblasts HSF7. Effects of celecoxib treatment were assessed by clonogenic cell survival, Western analysis, and quantification of residual DNA damage by γH 2 AX foci assay. Results: Celecoxib treatment resulted in a pronounced radiosensitization of A549, HCT116, and HSF7 cells, whereas FaDu and HH4dd cells were not radiosensitized. The observed radiosensitization could neither be correlated with basal COX-2 expression pattern nor with basal production of prostaglandin E2, but was depended on the ability of celecoxib to inhibit basal and radiation-induced nuclear transport of epidermal growth factor receptor (EGFR). The nuclear EGFR transport was strongly inhibited in A549-, HSF7-, and COX-2-deficient HCT116 cells, which were radiosensitized, but not in FaDu and HH4dd cells, which resisted celecoxib-induced radiosensitization. Celecoxib inhibited radiation-induced DNA-PK activation in A549, HSF7, and HCT116 cells, but not in FaDu and HH4dd cells. Consequentially, celecoxib increased residual γH2AX foci after irradiation, demonstrating that inhibition of DNA repair has occurred in responsive A549, HCT116, and HSF7 cells only. Conclusions: Celecoxib enhanced radiosensitivity by inhibition of EGFR-mediated mechanisms of radioresistance, a signaling that was independent of COX-2 activity. This novel observation may have therapeutic implications such that COX-2 inhibitors may improve therapeutic efficacy of radiation even in patients whose tumor radioresistance is not dependent on COX-2

  18. Radiosensitivity of Patient-Derived Glioma Stem Cell 3-Dimensional Cultures to Photon, Proton, and Carbon Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Chiblak, Sara; Tang, Zili [German Cancer Consortium, Heidelberg (Germany); Molecular and Translational Radiation Oncology, Heidelberg Ion Therapy Center, Heidelberg Institute of Radiation Oncology, University of Heidelberg Medical School and National Center for Tumor Diseases, German Cancer Research Center, Heidelberg (Germany); Campos, Benito; Gal, Zoltan; Unterberg, Andreas [Division of Neurological Research, Department of Neurosurgery, University of Heidelberg Medical School, Heidelberg (Germany); Debus, Jürgen [German Cancer Consortium, Heidelberg (Germany); Molecular and Translational Radiation Oncology, Heidelberg Ion Therapy Center, Heidelberg Institute of Radiation Oncology, University of Heidelberg Medical School and National Center for Tumor Diseases, German Cancer Research Center, Heidelberg (Germany); Herold-Mende, Christel [Division of Neurological Research, Department of Neurosurgery, University of Heidelberg Medical School, Heidelberg (Germany); Abdollahi, Amir, E-mail: a.amir@dkfz.de [German Cancer Consortium, Heidelberg (Germany); Molecular and Translational Radiation Oncology, Heidelberg Ion Therapy Center, Heidelberg Institute of Radiation Oncology, University of Heidelberg Medical School and National Center for Tumor Diseases, German Cancer Research Center, Heidelberg (Germany)

    2016-05-01

    Purpose: To investigate the radiosensitivity of primary glioma stem cell (GSC) cultures with different CD133 status in a 3-dimensional (3D) model after photon versus proton versus carbon irradiation. Methods and Materials: Human primary GSC spheroid cultures were established from tumor specimens of six consented glioblastoma patients. Human U87MG was used as a classical glioblastoma radioresistant cell line. Cell suspensions were generated by mechanical dissociation of GSC spheroids and embedded in a semi-solid 3D matrix before irradiation. Spheroid-like colonies were manually counted by microscopy. Cells were also recovered and quantified by fluorescence. CD133 expression and DNA damage were evaluated by flow cytometry. Results: The fraction of CD133{sup +} cells varied between 0.014% and 96% in the six GSC cultures and showed a nonsignificant correlation with plating efficiency and survival fractions. The 4 most photon-radioresistant GSC cultures were NCH644, NCH421k, NCH441, and NCH636. Clonogenic survival for proton irradiation revealed relative biologic effectiveness (RBE) in the range of 0.7-1.20. However, carbon irradiation rendered the photon-resistant GSC cultures sensitive, with average RBE of 1.87-3.44. This effect was partly attributed to impaired capability of GSC to repair carbon ion–induced DNA double-strand breaks as determined by residual DNA repair foci. Interestingly, radiosensitivity of U87 cells was comparable to GSC cultures using clonogenic survival as the standard readout. Conclusions: Carbon irradiation is effective in GSC eradication with similar RBE ranges approximately 2-3 as compared with non-stem GSC cultures (U87). Our data strongly suggest further exploration of GSC using classic radiobiology endpoints such as the here-used 3D clonogenic survival assay and integration of additional GSC-specific markers.

  19. Radiosensitivity of Patient-Derived Glioma Stem Cell 3-Dimensional Cultures to Photon, Proton, and Carbon Irradiation

    International Nuclear Information System (INIS)

    Chiblak, Sara; Tang, Zili; Campos, Benito; Gal, Zoltan; Unterberg, Andreas; Debus, Jürgen; Herold-Mende, Christel; Abdollahi, Amir

    2016-01-01

    Purpose: To investigate the radiosensitivity of primary glioma stem cell (GSC) cultures with different CD133 status in a 3-dimensional (3D) model after photon versus proton versus carbon irradiation. Methods and Materials: Human primary GSC spheroid cultures were established from tumor specimens of six consented glioblastoma patients. Human U87MG was used as a classical glioblastoma radioresistant cell line. Cell suspensions were generated by mechanical dissociation of GSC spheroids and embedded in a semi-solid 3D matrix before irradiation. Spheroid-like colonies were manually counted by microscopy. Cells were also recovered and quantified by fluorescence. CD133 expression and DNA damage were evaluated by flow cytometry. Results: The fraction of CD133"+ cells varied between 0.014% and 96% in the six GSC cultures and showed a nonsignificant correlation with plating efficiency and survival fractions. The 4 most photon-radioresistant GSC cultures were NCH644, NCH421k, NCH441, and NCH636. Clonogenic survival for proton irradiation revealed relative biologic effectiveness (RBE) in the range of 0.7-1.20. However, carbon irradiation rendered the photon-resistant GSC cultures sensitive, with average RBE of 1.87-3.44. This effect was partly attributed to impaired capability of GSC to repair carbon ion–induced DNA double-strand breaks as determined by residual DNA repair foci. Interestingly, radiosensitivity of U87 cells was comparable to GSC cultures using clonogenic survival as the standard readout. Conclusions: Carbon irradiation is effective in GSC eradication with similar RBE ranges approximately 2-3 as compared with non-stem GSC cultures (U87). Our data strongly suggest further exploration of GSC using classic radiobiology endpoints such as the here-used 3D clonogenic survival assay and integration of additional GSC-specific markers.

  20. Radiosensitivity of soft tissue sarcomas

    International Nuclear Information System (INIS)

    Hirano, Toru; Iwasaki, Katsuro; Suzuki, Ryohei; Monzen, Yoshio; Hombo, Zenichiro

    1989-01-01

    The correlation between the effectiveness of radiation therapy and the histology of soft tissue sarcomas was investigated. Of 31 cases with a soft tissue sarcoma of an extremity treated by conservative surgery and postoperative radiation of 3,000-6,000 cGy, local recurrence occurred in 12; 5 out of 7 synovial sarcomas, 4 of 9 MFH, one of 8 liposarcomas, none of 4 rhabdomyosarcomas and 2 of 3 others. As for the histological subtyping, the 31 soft tissue sarcomas were divided into spindle cell, pleomorphic cell, myxoid and round cell type, and recurrence rates were 75%, 33.3%, 16.7% and 0%, respectively. From the remarkable difference in recurrent rate, it was suggested that round cell and myxoid type of soft tissue sarcomas showed a high radiosensitivity compared to the spindle cell type with low sensitivity. Clarifying the degree of radiosensitivity is helpful in deciding on the management of limb salvage in soft tissue sarcomas of an extremity. (author)