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Sample records for differential radiosensitizing potential

  1. 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

  2. Differential Radiosensitizing Potential of Temozolomide in MGMT Promoter Methylated Glioblastoma Multiforme Cell Lines

    International Nuclear Information System (INIS)

    Nifterik, Krista A. van; Berg, Jaap van den; Stalpers, Lukas J.A.; Lafleur, M. Vincent M.; Leenstra, Sieger; Slotman, Ben J.; Hulsebos, Theo J.M.; Sminia, Peter

    2007-01-01

    Purpose: To investigate the radiosensitizing potential of temozolomide (TMZ) for human glioblastoma multiforme (GBM) cell lines using single-dose and fractionated γ-irradiation. Methods and Materials: Three genetically characterized human GBM cell lines (AMC-3046, VU-109, and VU-122) were exposed to various single (0-6 Gy) and daily fractionated doses (2 Gy per fraction) of γ-irradiation. Repeated TMZ doses were given before and concurrent with irradiation treatment. Immediately plated clonogenic cell-survival curves were determined for both the single-dose and the fractionated irradiation experiments. To establish the net effect of clonogenic cell survival and cell proliferation, growth curves were determined, expressed as the number of surviving cells. Results: All three cell lines showed MGMT promoter methylation, lacked MGMT protein expression, and were sensitive to TMZ. The isotoxic TMZ concentrations used were in a clinically feasible range of 10 μmol/L (AMC-3046), 3 μmol/L (VU-109), and 2.5 μmol/L (VU-122). Temozolomide was able to radiosensitize two cell lines (AMC 3046 and VU-122) using single-dose irradiation. A reduction in the number of surviving cells after treatment with the combination of TMZ and fractionated irradiation was seen in all three cell lines, but only AMC 3046 showed a radiosensitizing effect. Conclusions: This study on TMZ-sensitive GBM cell lines shows that TMZ can act as a radiosensitizer and is at least additive to γ-irradiation. Enhancement of the radiation response by TMZ seems to be independent of the epigenetically silenced MGMT gene

  3. Differential radiosensitivity among B cell subpopulations

    International Nuclear Information System (INIS)

    Riggs, J.E.

    1988-01-01

    The selective radiosensitivity of sIgM >> sIgD marginal zone B cells is associated with the selective loss of B cell function. The simultaneous restoration of impaired function and recovery of these cells with time supports this premise. B cell recovery, delayed one week after irradiation, is in progress at two weeks, and virtually complete by three weeks. XID mice reveal similar recovery kinetics although there are fewer recovering cells and these bear reduced levels of Ia. This observation represents additional evidence that xid B cells are distinct from those of normal mice. The simultaneous loss, and concurrent recovery, of sIgM >> sIgD B cells and TI-2 responsiveness in irradiated mice suggests the existence of a unique B cell subpopulation possessing both phenotypes. Additional support for this hypothesis is provided by demonstrating that splenocytes, depleted of IgD + cells adoptively reconstitute this response in XID mice. The peritoneal B cell pool, which, compared to the spleen, consist of increased numbers of sIgM >> sIgD B cells, is shown to be a source of radiosensitive B cells that are TI-2 responsive. These observations represent additional evidence for an association between sIgM >> sIgD B cells and TI-2 responsiveness

  4. Differential radiosensitivity on a tissue level in Delphinium ajacis

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    Mandal, S K; Basu, R K [Bose Research Inst., Calcutta (India). Cryogenetics Lab.

    1980-09-01

    Root, leaf, pollen mother cell and endosperm of D.ajacis showed differential sensitivity as measured by X-ray-induced chromosomal aberrations at mitotic anaphase and telophase stages of the first and second division cycles after irradiation. These tissues differed significantly in Interphase Chromosome Volume (ICV) values. In all the tissues the percentage of aberrant cells increased linearly with increase in X-ray dose. Though endosperm had the largest ICV value it was the most radioresistant tissue tested. The relative radiosensitivity of the other 3 tissues was positively correlated with ICV value. The radioresistance of endosperm is probably due to factors unique to this tissue which remained obscure.

  5. 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.

  6. Potential of radiosensitizing agents in cancer chemo-radiotherapy

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    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.

  7. Determination of one-electron reduction potentials of some radiosensitive compounds by pulse radiolysis

    International Nuclear Information System (INIS)

    Zuo Zhihua; Yao Side; Li Hucheng; Lin Nianyun; Jin Yizun

    1994-01-01

    One-electron reduction potential (E 7 1 ) is one of the important parameters of radiosensitive compound with high electron affinity. In this work one-electron reduction potentials of some radiosensitizers, such as Miso, 911, CMNa, SMU-1, SMU-2, SMD, SNN, S 3 and BSO, were determined pulse radiolytically by using anthraquinone-2-sulfate (AQS), duroquinone (DQ) and methyl viologen (MV 2+ ) as references

  8. 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

  9. Potential radiosensitizing agents. 5. 2-Substituted benzimidazole derivatives

    International Nuclear Information System (INIS)

    Gupta, R.P.; Larroquette, C.A.; Agrawal, K.C.

    1982-01-01

    A series of 2-substituted benzimidazoles and their derivatives have been synthesized and tested for their ability to selectively sensitize hypoxic Chinese hamster cells (V-79) toward the lethal effect of ionizing radiation. These compounds were prepared by reacting the 2-substituted benzimidazoles with 1,2-epoxy-3-methoxypropane in the presence of potassium carbonate. Reaction of the 2-nitro and 2-methylfonyl analogue with the epoxide also yielded a cyclized material, which was confirmed to be a benzimidazo[2,1-b]oxazole. In an attempt to increase the electron affinity, 5- or 6-nitro-2-substituted-benzimidazoles were also synthesized and then reacted with the epoxide to yield the corresponding 1-substituted derivatives. The results of the biological tests for the radiosensitizing activity of these agents against Chinese hamster cells (V-79) in culture indicated that the 2-nitro-substituted analogues were the most effective sensitizers in this series

  10. Differential radiosensitivity of seeds, seedlings and callus cultures of Petunia inflata

    International Nuclear Information System (INIS)

    Bapat, V.A.; Rao, P.S.

    1976-01-01

    A comparative study of the effects of γ-irradiation on seeds, seedlings and callus cultures of Petunia inflata showed striking differences in radiosensitivity as reflected in differences in mean fresh and dry weights, seedling height and morphology. Seeds subjected to low doses (4-6 kR) of irradiation showed stimulation of seedling height. Direct exposure of seedlings to high doses (10 kR) of irradiation caused inhibition in their development. Callus cultures, however, were more radioresistant compared to seeds and seedlings. Tissues grown on either an irradiated nutrient medium or on a medium in which sucrose alone had been irradiated, showed a marked inhibition in their growth potential

  11. 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)

  12. Oncogenes and radiosensitivity: in vitro studies. Potential impact in radiotherapy

    International Nuclear Information System (INIS)

    Alapetite, C.; Moustacchi, E.; Cosset, J.M.

    1992-01-01

    It is of interest to address the question of whether or not activated oncogenes can influence tumorigenic cell response to radiations. Malignant transformation through transfection of oncogenes offers a possibility for in vitro comparison of transformed cells and parental cells. Murin cellular system analysis suggests an acquisition of radioresistance through some oncogenes transfection. In human cells, only a limited number of oncogenes (ras and myc) has been studied so far. To date, no crucial influence could be demonstrated. The extension of the analysis to other oncogenes and suppressor genes could potentially be helpful for the choice and the modalities of cancer treatment

  13. Phytochemicals with radioprotection and radio-sensitizing potential

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    Tripathi, Yamini B., E-mail: yaminiok@yahoo.com [Dept. of Medicinal Chemistry, Institute of Medical Sciences, Banaras Hindu University, Varanasi (India)

    2012-07-01

    Ionizing radiation induces DNA damage and are harmful to mankind. They act through free radical generation, which target the double bonds of all cellular macromolecules. The radiation damage may be classified as probabilistic or deterministic, depending on the dose of radiation exposure. Since radiation affects multiple organs so those drugs which protect many organs, would be more beneficial. In this process herbal extracts, which are cocktail of several phyto-chemicals, would be more promising. Initially sulphur containing bio-molecules were identified as radio-protector, but now many secondary metabolites from plant kingdom, have been reported to be radio-protective. They have different mechanism of action, but most of them either prevent the FR induced DNA damage or accelerate the DNA repair process. Aminofostine, WR-2721, 159243, 2926 are some of the examples. However they have limited use because of associated cytotoxicity. Eicosanoids, topoisornerase inhibitors (e.g. camptothecin, topotecan), and the hypoxia-activated anthraquinone AQ4N have shown radioprotecting potential. Several plant products, derived from Tulsi, Vinca alkaloids, taxans, turmeric, Rubia cordifolia, Semecarpus anacardium and several plants rich in polyphenols and flavones have shown hemotherapeutic potential. Similarly, Hippophae, rhodiola imbricata, Podophyllum hexandrum, Ocimum sancturn, Plumbago zeylanica etc have shown radioprotection. Rubia cordifolia has shown both chemotherapeutic and radioprotective property in rats and A-431 cells. Similarly Semecarpus anacardium extract has shown cell cycle arrest in DU-145 cells. (author)

  14. Phytochemicals with radioprotection and radio-sensitizing potential

    International Nuclear Information System (INIS)

    Tripathi, Yamini B.

    2012-01-01

    Ionizing radiation induces DNA damage and are harmful to mankind. They act through free radical generation, which target the double bonds of all cellular macromolecules. The radiation damage may be classified as probabilistic or deterministic, depending on the dose of radiation exposure. Since radiation affects multiple organs so those drugs which protect many organs, would be more beneficial. In this process herbal extracts, which are cocktail of several phyto-chemicals, would be more promising. Initially sulphur containing bio-molecules were identified as radio-protector, but now many secondary metabolites from plant kingdom, have been reported to be radio-protective. They have different mechanism of action, but most of them either prevent the FR induced DNA damage or accelerate the DNA repair process. Aminofostine, WR-2721, 159243, 2926 are some of the examples. However they have limited use because of associated cytotoxicity. Eicosanoids, topoisornerase inhibitors (e.g. camptothecin, topotecan), and the hypoxia-activated anthraquinone AQ4N have shown radioprotecting potential. Several plant products, derived from Tulsi, Vinca alkaloids, taxans, turmeric, Rubia cordifolia, Semecarpus anacardium and several plants rich in polyphenols and flavones have shown hemotherapeutic potential. Similarly, Hippophae, rhodiola imbricata, Podophyllum hexandrum, Ocimum sancturn, Plumbago zeylanica etc have shown radioprotection. Rubia cordifolia has shown both chemotherapeutic and radioprotective property in rats and A-431 cells. Similarly Semecarpus anacardium extract has shown cell cycle arrest in DU-145 cells. (author)

  15. Radiosensitizing potential of gemcitabine (2',2'-difluoro-2'-deoxycytidine) within the cell cycle in vitro

    International Nuclear Information System (INIS)

    Latz, Detlev; Fleckenstein, Katharina; Eble, Michael; Blatter, Johannes; Wannenmacher, Michael; Weber, Klaus J.

    1998-01-01

    Purpose: Gemcitabine (2',2'-difluorodeoxycytidine; dFdCyd) is a new deoxycitidine analog which exhibits substantial activity against solid tumors and radiosensitizing properties in vitro. To examine cell cycle-specific effects of a combined treatment with gemcitabine and radiation, the in vitro clonogenic survival of two different cell lines was measured for cells from log-phase culture, G1 and S-phase cells. Methods and Materials: Chinese hamster (V79) and human colon carcinoma (Widr) cells were exposed to different radiation doses and for different points of time relative to gemcitabine treatment (2 h). Experiments were also carried out with different cell-cycle populations obtained after mitotic selection (V79) or after serum stimulation of plateau-phase cells (Widr). The resulting survival curves were analyzed according to the LQ model, and mean inactivation doses (MID) and the cell cycle-specific enhancement ratios (ER) were calculated from the survival curve parameters. Results: Effectiveness of combined treatment of log-phase cells was greatest when cells were irradiated at the end of the gemcitabine exposure [ER: 1.28 (V79), 1.24 (Widr)]. For later times after the removal of the drug, radiosensitization declined, approaching independent toxicity. From the time course of interactive-type damage decay half-life values of 75 min (V79) and 92 min (Widr) were derived. Gemcitabine did not radiosensitize G1 Widr cells or V79 cells from the G1/S border, but substantial radiosensitization was observed for the S-phase cell preparations [ER: 1.45 (V79-lateS), 1.57 (Widr)]. Conclusions: Treatment of cells with gemcitabine immediately before irradiation eliminates, or at least greatly reduces, the variation in radiosensitivity during the cell cycle that is manifested by radioresistance during S phase. This reversal of S-phase radioresistance could imply that gemcitabine interferes with the potentially lethal damage repair/fixation pathway. Other approaches have been

  16. Immunosuppression by hypoxic cell radiosensitizers: a phenomenon of potential clinical importance

    International Nuclear Information System (INIS)

    Rockwell, S.; Kapp, D.S.

    1982-01-01

    The nitroimidazoles metronidazole, misonidazol, and desmethyl misonidazole are currently undergoing clinical trials as possible adjuncts to radiotherapy. Ongoing clinical trials are evaluating the effectiveness of these agents and also documenting the pharmacokinetics and toxicities of radiosensitizing doses of these drugs in man. A variety of toxic effects have been noted in man, including anorexia, nausea and vomiting, peripheral neuropathy, central nervous system symptoms, ototoxicity, allergy, and fear. Laboratory studies have also suggested that these agents have potential to be mutagenic, carcinogenic, and teratogenic. In the editorial presented, the author attempts to draw attention to an additional toxic effect of nitroimidazoles - the inhibition of cell-mediated immune responses

  17. 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

  18. 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

  19. Development of bimetallic (Zn@Au) nanoparticles as potential PET-imageable radiosensitizers.

    Science.gov (United States)

    Cho, Jongmin; Wang, Min; Gonzalez-Lepera, Carlos; Mawlawi, Osama; Cho, Sang Hyun

    2016-08-01

    . The Monte Carlo results showed that radioactive Zn@Au NPs and solid GNPs provided similar characteristics in terms of their secondary electron spectra when irradiated. The Zn@Au NPs developed in this investigation have the potential to be used as PET-imageable radiosensitizers for radiotherapy applications as well as PET tracers for molecular imaging applications.

  20. Development of bimetallic (Zn@Au) nanoparticles as potential PET-imageable radiosensitizers

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Jongmin, E-mail: jongmin.cho@okstate.edu [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Wang, Min [Department of Chemistry, Rice University, Houston, Texas 77005 (United States); Gonzalez-Lepera, Carlos [Department of Nuclear Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Mawlawi, Osama [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Cho, Sang Hyun [Departments of Radiation Physics and Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

    2016-08-15

    signals from mostly decaying {sup 66}Ga. The Monte Carlo results showed that radioactive Zn@Au NPs and solid GNPs provided similar characteristics in terms of their secondary electron spectra when irradiated. Conclusions: The Zn@Au NPs developed in this investigation have the potential to be used as PET-imageable radiosensitizers for radiotherapy applications as well as PET tracers for molecular imaging applications.

  1. The radiation chemistry of Hoechst 33258 and its potential radiosensitizing analogues

    International Nuclear Information System (INIS)

    Nel, P.; Cooper, R.

    1996-01-01

    Collaborative research between Peter MacCallum Cancer Institute and The University of Melbourne is aimed to investigate the photochemistry and radiation chemistry of the halogenated analogues m-I Hoechst and o-I Hoechst (which are being developed as potential radiosensitizers). Studies were conducted on Hoechst 33258, phenyl Hoechst, m-I Hoechst and o-I Hoechst. The chemical interaction between the Hoechst analogues and the radiolysis products of water (the hydroxy radical and the aqueous electron) were investigated by saturating aqueous solutions with nitrogen or nitrous oxide (an electron scavenger) and using 2-propanol as a hydroxy radical scavenger. Hoechst 33258 was investigated at pH 5 and pH 9. Transient absorption spectra of micromolar solutions saturated with nitrogen or nitrous oxide suggest the formation of hydroxyl radical adduct(s). The rate of formation of these transient spectra was observed to be dependent on the concentration of Hoechst 33258. Phenyl Hoechst, m- I Hoechst and o-I Hoechst were studied at pH 5. Spectra again suggest the formation of hydroxy radical adducts and that both m-I Hoechst and o-I Hoechst react with aqueous electrons

  2. Hyperthermia radiosensitization in human glioma cells comparison of recovery of polymerase activity, survival, and potentially lethal damage repair

    International Nuclear Information System (INIS)

    Raaphorst, G.P.; Feeley, M.M.

    1994-01-01

    DNA polymerase inactivation is compared to thermal radiosensitization and inhibition of damage recovery in human glioma cells. Two human glioma cell lines (U87MG and U373MG) were exposed to hyperthermia and irradiation. Hyperthermia was given at 43 degrees C and 45 degrees C and DNA polymerase α + δ + ε and β activities were measured. Hyperthermia was given at various times before irradiation and the degree of radiosensitization and polymerase activity was assessed at various times after heating. In addition the ability of cells to undergo repair of potentially lethal radiation damage was assessed for cells irradiated at various times after heating. Polymerase α + δ + ε and polymerase β both recovered after heating but polymerase β was faster and was complete in U373MG but not in the U87MG cell lines after 48 h incubation after heating (45 degrees C, 60 min). Incubation, between hyperthermia and irradiation resulted in a loss of radiosensitization and a loss of inhibition of repair of potentially lethal damage. These changes correlated well with recovery of polymerase β but not with polymerase α + δ + ε. The correlation of polymerase β activity and thermoradiosensitization and its recovery indicate that polymerase β may be one of the mechanisms involved in thermoradiosensitization. 35 refs., 7 figs

  3. ZnFe2O4 nanoparticles for potential application in radiosensitization

    International Nuclear Information System (INIS)

    Hidayatullah, M; Nurhasanah, I; Budi, W S

    2016-01-01

    Radiosensitizer is a material that can increase the effects of radiation in radiotherapy application. Various materials with high effective atomic number have been developed as a radiosensitizer, such as metal, iron oxide and quantum dot. In this study, ZnFe 2 O 4 nanoparticles are included in iron oxide class were synthesized by precipitation method from the solution of zinc nitrate and ferrite nitrate and followed by calcination at 700° C for 3 hours. The XRD pattern shows that most of the observed peaks can be indexed to the cubic phase of ZnFe 2 O 4 with a lattice parameter of 8.424 Å. SEM image reveals that nanoparticles are the sphere-like shape with size in the range 84-107 nm. The ability of ZnFe 2 O 4 nanoparticles as radiosensitizer was examined by loading those nanoparticles into Escherichia coli cell culture which irradiated with photon energy of 6 MV at a dose of 2 Gy. ZnFe 2 O 4 nanoparticles showed ability to increase the absorbed dose by 0.5 to 1.0 cGy/g. In addition, the presence of 1 g/L ZnFe 2 O 4 nanoparticles resulted in an increase radiation effect by 6.3% higher than if exposed to radiation only. These results indicated that ZnFe 2 O 4 nanoparticles can be used as the radiosensitizer for increasing radiation effect in radiotherapy. (paper)

  4. 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.

  5. The current status of drug development of hypoxic cell radiosensitizers and their potential role in gynecologic oncology

    International Nuclear Information System (INIS)

    Coleman, C.N.; Ballon, S.C.; Howes, A.E.; Martinez, A.; Halsey, J.; Hirst, V.K.

    1984-01-01

    Both laboratory and clinical data suggest that hypoxia contributes to the failure of radiotherapy to achieve local control of bulky gynecologic tumors. As part of a Phase I trial of hypoxic cell radiosensitizers, 19 women at Stanford University with advanced (n . 6) or recurrent (n . 13) pelvic neoplasms were treated with radiotherapy plus desmethylmisonidazole. Complete or partial response occurred in 42% of patients with some patients achieving local control for over 1 year. It is unknown if the sensitizer added to the results of radiotherapy alone. A Phase I trial of a theoretically superior sensitizer, SR-2508, is soon to begin. It is anticipated that the dose-limiting neurotoxicity seen with misonidazole and desmethylmisonidazole will either be eliminated or will occur at a much higher total dose of drug. Many patients with gynecologic tumors could potentially benefit from participation in the new drug trials

  6. Differential radiosensitivity of mouse embryonic neurons and glia in cell culture

    International Nuclear Information System (INIS)

    Dambergs, R.; Kidson, C.

    1977-01-01

    The responses of neurons and glial cells to ultraviolet and γ-radiation were studied in cell cultures of embryonic mouse brains. A decrease in the ratio of glia to neurons occurred after both forms of irradiation. [ 3 H]thymidine labelling followed by autoradiography revealed that all glia were capable of replication, whereas 70 percent of neurons were non-replicating under the conditions of the study. Ultraviolet radiation caused a decrease in the proportion of replicating neurons but did not affect the proportion of replicating glia, whereas γ-radiation caused a decrease in DNA replication in both cell types. Levels of ultraviolet radiation-induced unscheduled DNA synthesis were lower in neurons than in glia. It is concluded that sensitivity to both ionizing and ultraviolet radiation of neurons and glial cells in embryonic brain cultures is determined primarily by the capacity for and state of DNA replication. Neurons which have already reached the stage of terminal differentiation are more resistant than replicating neurons of glial cells

  7. 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.

  8. 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

  9. Pharmacological targeting of the ephrin receptor kinase signalling by GLPG1790 in vitro and in vivo reverts oncophenotype, induces myogenic differentiation and radiosensitizes embryonal rhabdomyosarcoma cells

    Directory of Open Access Journals (Sweden)

    Francesca Megiorni

    2017-10-01

    Full Text Available Abstract Background EPH (erythropoietin-producing hepatocellular receptors are clinically relevant targets in several malignancies. This report describes the effects of GLPG1790, a new potent pan-EPH inhibitor, in human embryonal rhabdomyosarcoma (ERMS cell lines. Methods EPH-A2 and Ephrin-A1 mRNA expression was quantified by real-time PCR in 14 ERMS tumour samples and in normal skeletal muscle (NSM. GLPG1790 effects were tested in RD and TE671 cell lines, two in vitro models of ERMS, by performing flow cytometry analysis, Western blotting and immunofluorescence experiments. RNA interfering experiments were performed to assess the role of specific EPH receptors. Radiations were delivered using an x-6 MV photon linear accelerator. GLPG1790 (30 mg/kg in vivo activity alone or in combination with irradiation (2 Gy was determined in murine xenografts. Results Our study showed, for the first time, a significant upregulation of EPH-A2 receptor and Ephrin-A1 ligand in ERMS primary biopsies in comparison to NSM. GLPG1790 in vitro induced G1-growth arrest as demonstrated by Rb, Cyclin A and Cyclin B1 decrease, as well as by p21 and p27 increment. GLPG1790 reduced migratory capacity and clonogenic potential of ERMS cells, prevented rhabdosphere formation and downregulated CD133, CXCR4 and Nanog stem cell markers. Drug treatment committed ERMS cells towards skeletal muscle differentiation by inducing a myogenic-like phenotype and increasing MYOD1, Myogenin and MyHC levels. Furthermore, GLPG1790 significantly radiosensitized ERMS cells by impairing the DNA double-strand break repair pathway. Silencing of both EPH-A2 and EPH-B2, two receptors preferentially targeted by GLPG1790, closely matched the effects of the EPH pharmacological inhibition. GLPG1790 and radiation combined treatments reduced tumour mass by 83% in mouse TE671 xenografts. Conclusions Taken together, our data suggest that altered EPH signalling plays a key role in ERMS development and that

  10. Retention of the In Vitro Radiosensitizing Potential of Gemcitabine Under Anoxic Conditions, in p53 Wild-Type and p53-Deficient Non-Small-Cell Lung Carcinoma Cells

    International Nuclear Information System (INIS)

    Wouters, An; Pauwels, Bea; Lambrechts, Hilde A.J.; Pattyn, Greet G.O.; Ides, Johan; Baay, Marc; Meijnders, Paul; Peeters, Marc; Vermorken, Jan B.; Lardon, Filip

    2011-01-01

    Purpose: Whereas radiosensitization by gemcitabine is well studied under normal oxygen conditions, little is known about its radiosensitizing potential under reduced oxygen conditions. Therefore, the present study evaluated the impact of anoxia on gemcitabine-mediated radiosensitization. Methods and Materials: The clonogenic assay was performed in three isogenic A549 cell lines differing in p53 status (24 h, 0-15 nM gemcitabine, 0-8 Gy irradiation, normoxia vs. anoxia). Using radiosensitizing conditions, cells were collected for cell cycle analysis and apoptosis detection. Results: Whereas wild-type p53 A549-LXSN cells were more sensitive to radiation than p53-deficient A549-E6 cells, both cell lines showed similar radiosensitization by gemcitabine under normoxia and anoxia. Independent of p53 functionality, gemcitabine was able to overcome anoxia-induced G 0/1 arrest and established an (early) S phase block in normoxic and anoxic cells. The percentage early and late apoptotic/necrotic cells increased with the gemcitabine/radiation combination, with a significant difference between A549-LXSN and A549-E6. Conclusions: This study is the first to show that gemcitabine retains its radiosensitizing potential under low oxygen conditions. Although radiosensitization was observed in both p53 wild-type and p53-deficient cells, p53 status might influence induction of apoptosis after gemcitabine/radiation treatment, whereas no effect on cell cycle progression was noticed.

  11. 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

  12. 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

  13. 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

  14. Differential sensitivity of p53+ and p53- cells to caffeine-induced radiosensitization and override of G2 delay

    International Nuclear Information System (INIS)

    Powell, S.N.; DeFrank, J.S.; Connell, P.; Eogan, M.; Preffer, F.; Dombkowski, D.; Tang, W.; Friend, S.H.

    1995-01-01

    Purpose: Most drug discovery efforts have focused on finding new DNA damaging agents to kill tumor cells preferentially. An alternative approach is to find ways to increase tumor specific killing by modifying tumor specific responses to that damage. We asked whether cells lacking the G1/S arrest in response to X-rays are more sensitive to X-ray damage when treated with agents that override G2/M arrest. Materials and Methods: Mouse embryonic fibroblasts genetically matched to be (+/+) or (-/-) p53 and rat embryonic fibroblasts (REF) made (+) or (-) for wild-type p53 function by transfection were irradiated with and without caffeine, a known checkpoint inhibitor. Caffeine treatment was maintained for 24 hours from 1 hour prior to irradiation. Cell survival following ionizing radiation was measured by clonogenic assay. For cell-cycle analysis, cells were in exponential asynchronous growth at the time of irradiation. The proportion of cells in G1, S and G2/M phases of the cell cycle were recorded immediately before and following irradiation and subsequently at 3,6,9,12,24 and 48 hours following irradiation. Results: Caffeine was found to cause radiosensitzation at low dose (0.5mM) in (-/-) cells but not in (+/+) cells. The sensitization enhancement ratio (SER) was 1.45 at 0.1 survival and 1.56 at 0.01 survival. At this dose of caffeine, this SER reflected therapeutic gain as there was no detectable effect on (+/+) cells. At 1mM caffeine, sensitization of (-/-) cells was 1.77, but (+/+) cells now also showed sensitization (SER=1.25). In (-/-) cells at 0.1mM caffeine the SER was 1.5 at 0.01 survival. The transfected REF cells (functionally null for p53) also exhibited caffeine-induced radiosensitization at both 0.5 and 2mM caffeine with a SER 1.45 for 2mM at 0.1 survival. No significant sensitization could be demonstrated for REF cells at the same doses of caffeine. The REF cells, with wild-type p53, transfected with pCMVneo alone showed no change in radiosensitivity or

  15. Potential in stochastic differential equations: novel construction

    International Nuclear Information System (INIS)

    Ao, P

    2004-01-01

    There is a whole range of emergent phenomena in a complex network such as robustness, adaptiveness, multiple-equilibrium, hysteresis, oscillation and feedback. Those non-equilibrium behaviours can often be described by a set of stochastic differential equations. One persistent important question is the existence of a potential function. Here we demonstrate that a dynamical structure built into stochastic differential equation allows us to construct such a global optimization potential function. We present an explicit construction procedure to obtain the potential and relevant quantities. In the procedure no reference to the Fokker-Planck equation is needed. The availability of the potential suggests that powerful statistical mechanics tools can be used in nonequilibrium situations. (letter to the editor)

  16. 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

  17. Radiosensitivities of sensitized lymphocytes

    International Nuclear Information System (INIS)

    Taniguchi, Kazuto

    1979-01-01

    Immunization of mice with cell antigens such as allogeneic tumor cells or xenogeneic erythrocytes raises a variety of immune reactions mediated by T lymphocytes: i.e. delayed type hypersensitivity (DTH), cytotoxicity, and antibody production. The radiosensitivities of these reactions were examined in mice exposed to 600 R x-irradiation a few hours before or after immunization. 1) DTH to xenogeneic erythrocytes, as demonstrated by footpad reaction, was not suppressed by irradiation 3 h before or after immunization. DTH to allogeneic tumor cells, as demonstrated by a migration inhibition test, hardly developed in mice that had been irradiated before or after immunization. It may have belonged to distinct types of delayed reactions which were mediated by distinct subpopulations of T lymphocytes. 2) Cytotoxicity against allogeneic cells and xenogeneic erythrocytes showed almost the same radiosensitivity. It was scarcely detected in mice that had been irradiated before immunization. However, a low but definite degree of cytotoxicity was detected in mice that had been irradiated only a few hours after immunization. Solubilized allogeneic cells instead of native cells were used as immunizing antigens. It was also possible for precursor cells with cytotoxicity to acquire a radioresistant nature by immunization of solubilized antigens, but native cells were required as stimulation for radioresistant precursor cells to differentiated into nature cytotoxic effector cells. 3) Antibody production against xenogeneic erythrocytes or allogeneic cells was almost completely depleted in mice that had been irradiated before or after immunization. It is possible that antibody production essentially requires cell division and clonal expansion of B lymphocytes. (Bell, E.)

  18. 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

  19. The potential value of the neutral comet assay and the expression of genes associated with DNA damage in assessing the radiosensitivity of tumor cells.

    Science.gov (United States)

    Jayakumar, Sundarraj; Bhilwade, Hari N; Pandey, Badri N; Sandur, Santosh K; Chaubey, Ramesh C

    2012-10-09

    The assessment of tumor radiosensitivity would be particularly useful in optimizing the radiation dose during radiotherapy. Therefore, the degree of correlation between radiation-induced DNA damage, as measured by the alkaline and the neutral comet assays, and the clonogenic survival of different human tumor cells was studied. Further, tumor radiosensitivity was compared with the expression of genes associated with the cellular response to radiation damage. Five different human tumor cell lines were chosen and the radiosensitivity of these cells was established by clonogenic assay. Alkaline and neutral comet assays were performed in γ-irradiated cells (2-8Gy; either acute or fractionated). Quantitative PCR was performed to evaluate the expression of DNA damage response genes in control and irradiated cells. The relative radiosensitivity of the cell lines assessed by the extent of DNA damage (neutral comet assay) immediately after irradiation (4Gy or 6Gy) was in agreement with radiosensitivity pattern obtained by the clonogenic assay. The survival fraction of irradiated cells showed a better correlation with the magnitude of DNA damage measured by the neutral comet assay (r=-0.9; Pcomet assay (r=-0.73; Pcomet assay was better than alkaline comet assay for assessment of radiosensitivities of tumor cells after acute or fractionated doses of irradiation. © 2012 Elsevier B.V. All rights reserved.

  20. 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.

  1. γH2AX/53BP1 foci as a potential pre-treatment marker of HNSCC tumors radiosensitivity - preliminary methodological study and discussion

    Science.gov (United States)

    Falk, Martin; Horakova, Zuzana; Svobodova, Marketa; Masarik, Michal; Kopecna, Olga; Gumulec, Jaromir; Raudenska, Martina; Depes, Daniel; Bacikova, Alena; Falkova, Iva; Binkova, Hana

    2017-09-01

    In order to improve patients' post-treatment quality of life, a shift from surgery to non-surgical (chemo)radio-treatment is recognized in head and neck oncology. However, about half of HNSCC tumors are resistant to irradiation and an efficient marker of individual tumor radiosensitivity is still missing. We analyzed whether various parameters of DNA double strand break (DSB) repair determined in vitro can predict, prior to clinical treatment initiation, the radiosensitivity of tumors. We compared formation and decrease of γH2AX/53BP1 foci in 48 h after irradiating tumor cell primocultures with 2 Gy of γ-rays. To better understand complex tumor behavior, three different cell type primocultures - CD90-, CD90+, and a mixed culture of these cells - were isolated from 1 clinically radioresistant, 2 radiosensitive, and 4 undetermined HPV-HNSCC tumors and followed separately. While DSB repair was delayed and the number of persisting DSBs increased in the radiosensitive tumors, the results for the radioresistant tumor were similar to cultured normal human skin fibroblasts. Hence, DSB repair kinetics/efficiency may correlate with clinical response to radiotherapy for a subset of HNSCC tumors but the size (and therefore practical relevance) of this subset remains to be determined. The same is true for contribution of different cell type primocultures to tumor radioresistance.

  2. 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

  3. 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.

  4. 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)

  5. 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.

  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. 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

  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. 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. 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

  11. 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.

  12. 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

  13. 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.

  14. Hepatic differentiation potential of commercially available human mesenchymal stem cells.

    Science.gov (United States)

    Ong, Shin-Yeu; Dai, Hui; Leong, Kam W

    2006-12-01

    The ready availability and low immunogenicity of commercially available mesenchymal stem cells (MSC) render them a potential cell source for the development of therapeutic products. With cell source a major bottleneck in hepatic tissue engineering, we investigated whether commercially available human MSC (hMSC) can transdifferentiate into the hepatic lineage. Based on previous studies that find rapid gain of hepatic genes in bone marrow-derived stem cells cocultured with liver tissue, we used a similar approach to drive hepatic differentiation by coculturing the hMSC with rat livers treated or untreated with gadolinium chloride (GdCl(3)). After a 24-hour coculture period with liver tissue injured by GdCl(3) in a Transwell configuration, approximately 34% of the cells differentiated into albumin-expressing cells. Cocultured cells were subsequently maintained with growth factors to complete the hepatic differentiation. Cocultured cells expressed more hepatic gene markers, and had higher metabolic functions and P450 activity than cells that were only differentiated with growth factors. In conclusion, commercially available hMSC do show hepatic differentiation potential, and a liver microenvironment in culture can provide potent cues to accelerate and deepen the differentiation. The ability to generate hepatocyte-like cells from a commercially available cell source would find interesting applications in liver tissue engineering.

  15. Activation of human B lymphocytes. 8. Differential radiosensitivity of subpopulations of lymphoid cells involved in the polyclonally-induced PFC responses of peripheral blood B lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Fauci, A S; Pratt, K R; Whalen, G [National Inst. of Allergy and Infectious Diseases, Bethesda, MD (USA)

    1978-11-01

    The differential effect of various doses of irradiation on subpopulations of human peripheral blood lymphoid cells involved in the pokeweed mitogen induced PFC response against sheep red blood cells was studied. The plaque forming B cells were quite sensitive to low doses of irradiation with complete suppression of responses at 300 to 500 rad. On the contrary, helper T-cell function was resistant to 2000 rad. Co-culture of irradiated T cells with autologous or allogeneic B cells resulted in marked enhancement of PFC responses consistent with the suppression of naturally occurring suppressor cells with a resulting pure helper effect. Irradiated T-cell-depleted suspensions failed to produce this effect as did heat killed T cells, whereas mitomycin C treated T cells gave effects similar to irradiated T cells. These findings are consistent with a lack of requirement of cell division for a T-cell helper effect and a requirement of mitosis or another irradiation sensitive, mitomycin C sensitive process for a T-suppressor cell effect. These studies have potential relevance in the evaluation of subpopulations of human lymphoid cells involved in antibody production in normal individuals and in disease states.

  16. 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.

  17. Variational and potential formulation for stochastic partial differential equations

    International Nuclear Information System (INIS)

    Munoz S, A G; Ojeda, J; Sierra D, P; Soldovieri, T

    2006-01-01

    Recently there has been interest in finding a potential formulation for stochastic partial differential equations (SPDEs). The rationale behind this idea lies in obtaining all the dynamical information of the system under study from one single expression. In this letter we formally provide a general Lagrangian formalism for SPDEs using the Hojman et al method. We show that it is possible to write the corresponding effective potential starting from an s-equivalent Lagrangian, and that this potential is able to reproduce all the dynamics of the system once a special differential operator has been applied. This procedure can be used to study the complete time evolution and spatial inhomogeneities of the system under consideration, and is also suitable for the statistical mechanics description of the problem. (letter to the editor)

  18. 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

  19. 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

  20. 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

    depletion. In mice exposed to 100% O 2 , a significant component of skin radiosensitivity was due to diffusion of oxygen directly through the skin. Pentobarbitone anesthesia radiosensitized skin in mice exposed to 100% O 2 by a factor of 1.2, but did not further sensitize skin in mice exposed to carbogen. Conclusions: Glutathione levels and the local oxygen tension at the time of irradiation were important determinants of mouse foot skin radiosensitivity. The extent to which GSH levels altered the radiosensitivity of skin was critically dependent on the local oxygen tension. These results have significant implications for potential clinical application of GSH depletion

  1. Taxonomic and developmental aspects of radiosensitivity

    International Nuclear Information System (INIS)

    Harrison, F.L.; Anderson, S.L.

    1996-11-01

    Considerable information is available on the effects of radioactivity on adult and early life stages of organisms. The preponderance of data is on mortality after a single irradiation with relatively high doses. Unfortunately, because experiments were carried out under different conditions and for different time periods, the validity of comparing the results from different laxonomic groups is questionable. In general, the conclusions are that there is a relationship (1) between radioresistance to high doses of acute radiation and taxonomy of the organism, primitive forms being more radioresistant than complex vertebrates and (2) between radiosensitivity and developmental stage, early life stages being more sensitive than later stages. The first conclusion may be related to the capability of the organism to repopulate cells and to differentiate and redifferentiate them; the second to the rate of cellular division and to the degree of differentiation. In question, however, is the relevance of the responses from high levels of acute radiation to that of the responses to long-term exposure to low levels of radiation, which are ecologically of more interest. Data from studies of the effects of acute and chronic exposure on development of gametes and zygotes indicate that, for some fishes and invertebrates, responses at the cellular and molecular levels show effect levels comparable to those observed in some mammals. Acute doses between 0,05 and 0.5Cy and dose rates between 0.02 to 0.2mCy/h appear to define critical ranges in which detrimental effects on fertility are first observed in a variety of radiosensitive organisms. To better understand inherent radiosensitivity, we need more information on the ability of cells to repopulate and differentiate and to prevent or repair damage to biological critical molecules, such as DNA, because these factors may alter significantly organisms'' responses to radiation

  2. Taxonomic and developmental aspects of radiosensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, F.L. [Lawrence Livermore National Lab., CA (United States); Anderson, S.L. [Lawrence Berkeley National Lab., CA (United States)

    1996-11-01

    Considerable information is available on the effects of radioactivity on adult and early life stages of organisms. The preponderance of data is on mortality after a single irradiation with relatively high doses. Unfortunately, because experiments were carried out under different conditions and for different time periods, the validity of comparing the results from different laxonomic groups is questionable. In general, the conclusions are that there is a relationship (1) between radioresistance to high doses of acute radiation and taxonomy of the organism, primitive forms being more radioresistant than complex vertebrates and (2) between radiosensitivity and developmental stage, early life stages being more sensitive than later stages. The first conclusion may be related to the capability of the organism to repopulate cells and to differentiate and redifferentiate them; the second to the rate of cellular division and to the degree of differentiation. In question, however, is the relevance of the responses from high levels of acute radiation to that of the responses to long-term exposure to low levels of radiation, which are ecologically of more interest. Data from studies of the effects of acute and chronic exposure on development of gametes and zygotes indicate that, for some fishes and invertebrates, responses at the cellular and molecular levels show effect levels comparable to those observed in some mammals. Acute doses between 0,05 and 0.5Cy and dose rates between 0.02 to 0.2mCy/h appear to define critical ranges in which detrimental effects on fertility are first observed in a variety of radiosensitive organisms. To better understand inherent radiosensitivity, we need more information on the ability of cells to repopulate and differentiate and to prevent or repair damage to biological critical molecules, such as DNA, because these factors may alter significantly organisms` responses to radiation.

  3. Biophysical characteristics reveal neural stem cell differentiation potential.

    Directory of Open Access Journals (Sweden)

    Fatima H Labeed

    Full Text Available Distinguishing human neural stem/progenitor cell (huNSPC populations that will predominantly generate neurons from those that produce glia is currently hampered by a lack of sufficient cell type-specific surface markers predictive of fate potential. This limits investigation of lineage-biased progenitors and their potential use as therapeutic agents. A live-cell biophysical and label-free measure of fate potential would solve this problem by obviating the need for specific cell surface markers.We used dielectrophoresis (DEP to analyze the biophysical, specifically electrophysiological, properties of cortical human and mouse NSPCs that vary in differentiation potential. Our data demonstrate that the electrophysiological property membrane capacitance inversely correlates with the neurogenic potential of NSPCs. Furthermore, as huNSPCs are continually passaged they decrease neuron generation and increase membrane capacitance, confirming that this parameter dynamically predicts and negatively correlates with neurogenic potential. In contrast, differences in membrane conductance between NSPCs do not consistently correlate with the ability of the cells to generate neurons. DEP crossover frequency, which is a quantitative measure of cell behavior in DEP, directly correlates with neuron generation of NSPCs, indicating a potential mechanism to separate stem cells biased to particular differentiated cell fates.We show here that whole cell membrane capacitance, but not membrane conductance, reflects and predicts the neurogenic potential of human and mouse NSPCs. Stem cell biophysical characteristics therefore provide a completely novel and quantitative measure of stem cell fate potential and a label-free means to identify neuron- or glial-biased progenitors.

  4. Radiosensitivity of neuroblastoma

    International Nuclear Information System (INIS)

    Deacon, J.M.; Wilson, P.; Steel, G.G.

    1985-01-01

    Neuroblastoma is known to be clinically radioresponsive: it is possible to obtain local tumour control with relatively small doses of radiation. The main therapeutic problem, however, is one of metastatic disease, where in spite of modern combination chemotherapy, the prognosis remains poor. Systemic therapy with either drugs or radiation is dose-limited by toxicity to bone marrow stem cells. However, the advent of new technology which enables tumour cells to be removed from infiltrated marrow prior to autologous bone marrow ''rescue'' allows dose escalation, and makes the use of systemic irradiation in the treatment of stage IV disease feasible. The objective of this study was to investigate the radiobiology of neuroblastoma in detail, including intrinsic cellular radiosensitivity, repair capacity, and extrinsic dose-modifying factors which may affect tumour response in vivo. Cells at three levels of organisation were used: single cell suspensions multicellular tumour spheroids; and xenografts grown in immune-suppressed mice

  5. 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

  6. Application of differential evolution algorithm on self-potential data.

    Science.gov (United States)

    Li, Xiangtao; Yin, Minghao

    2012-01-01

    Differential evolution (DE) is a population based evolutionary algorithm widely used for solving multidimensional global optimization problems over continuous spaces, and has been successfully used to solve several kinds of problems. In this paper, differential evolution is used for quantitative interpretation of self-potential data in geophysics. Six parameters are estimated including the electrical dipole moment, the depth of the source, the distance from the origin, the polarization angle and the regional coefficients. This study considers three kinds of data from Turkey: noise-free data, contaminated synthetic data, and Field example. The differential evolution and the corresponding model parameters are constructed as regards the number of the generations. Then, we show the vibration of the parameters at the vicinity of the low misfit area. Moreover, we show how the frequency distribution of each parameter is related to the number of the DE iteration. Experimental results show the DE can be used for solving the quantitative interpretation of self-potential data efficiently compared with previous methods.

  7. Application of differential evolution algorithm on self-potential data.

    Directory of Open Access Journals (Sweden)

    Xiangtao Li

    Full Text Available Differential evolution (DE is a population based evolutionary algorithm widely used for solving multidimensional global optimization problems over continuous spaces, and has been successfully used to solve several kinds of problems. In this paper, differential evolution is used for quantitative interpretation of self-potential data in geophysics. Six parameters are estimated including the electrical dipole moment, the depth of the source, the distance from the origin, the polarization angle and the regional coefficients. This study considers three kinds of data from Turkey: noise-free data, contaminated synthetic data, and Field example. The differential evolution and the corresponding model parameters are constructed as regards the number of the generations. Then, we show the vibration of the parameters at the vicinity of the low misfit area. Moreover, we show how the frequency distribution of each parameter is related to the number of the DE iteration. Experimental results show the DE can be used for solving the quantitative interpretation of self-potential data efficiently compared with previous methods.

  8. 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

  9. Disulfiram attenuates osteoclast differentiation in vitro: a potential antiresorptive agent.

    Directory of Open Access Journals (Sweden)

    Hua Ying

    Full Text Available Disulfiram (DSF, a cysteine modifying compound, has long been clinically employed for the treatment of alcohol addiction. Mechanistically, DSF acts as a modulator of MAPK and NF-κB pathways signaling pathways. While these pathways are crucial for osteoclast (OC differentiation, the potential influence of DSF on OC formation and function has not been directly assessed. Here, we explore the pharmacological effects of DSF on OC differentiation, activity and the modulation of osteoclastogenic signaling cascades. We first analyzed cytotoxicity of DSF on bone marrow monocytes isolated from C57BL/6J mice. Upon the establishment of optimal dosage, we conducted osteoclastogenesis and bone resorption assays in the presence or absence of DSF treatment. Luciferase assays in RAW264.7 cells were used to examine the effects of DSF on major transcription factors activation. Western blot, reverse transcription polymerase chain reaction, intracellular acidification and proton influx assays were employed to further dissect the underlying mechanism. DSF treatment dose-dependently inhibited both mouse and human osteoclastogenesis, especially at early stages of differentiation. This inhibition correlated with a decrease in the expression of key osteoclastic marker genes including CtsK, TRAP, DC-STAMP and Atp6v0d2 as well as a reduction in bone resorption in vitro. Suppression of OC differentiation was found to be due, at least in part, to the blockade of several key receptor activators of nuclear factor kappa-B ligand (RANKL-signaling pathways including ERK, NF-κB and NFATc1. On the other hand, DSF failed to suppress intracellular acidification and proton influx in mouse and human osteoclasts using acridine orange quenching and microsome-based proton transport assays. Our findings indicate that DSF attenuates OC differentiation via the collective suppression of several key RANKL-mediated signaling cascades, thus making it an attractive agent for the treatment of OC

  10. 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

  11. Peptide receptor radionuclide therapy of Merkel cell carcinoma using 177lutetium-labeled somatostatin analogs in combination with radiosensitizing chemotherapy. A potential novel treatment based on molecular pathology

    International Nuclear Information System (INIS)

    Salavati, A.; Prasad, V.; Baum, R.P.; Schneider, C.P.; Herbst, R.

    2012-01-01

    Few studies have been published on the safety and feasibility of synchronous use of peptide receptor radionuclide therapy (PRRNT), as source of internal radiation therapy, in combination with chemotherapy. In this study we reported a 53-year-old man with stage IV Merkel cell carcinoma (MCC), who underwent synchronous internal radiation therapy and chemotherapy. Based on presumable poor prognosis with chemotherapy only, functional similarities of MCC with other neuroendocrine tumors and available evidence of effectiveness and safety of synchronous use of external beam radiation therapy and chemotherapy in treatment of high-risk MCC patients, our interdisciplinary neuroendocrine tumor board recommended him to add PRRNT to his ongoing chemotherapy. He received 2 courses of 177 Lu-DOTATATE(1, 4, 7, 10-Tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid-1-D-Phe1-Tyr3-Thr8-octreotide) in combination with ongoing 8 cycles of liposomal doxorubicin based on standard protocols. Response to therapy was evaluated by 18 F-fluorodeoxyglucose ( 18 F-FDG) and 68 gallium-somatostatin-receptor PET/CT. There was an impressive improvement of the clinical symptoms. However, follow-up positron emission tomography (PET)/CT studies showed mixed pattern of response. Synchronous use of PRRNT and radiosensitizing chemotherapy seems safe and feasible in high risk MCC patients, however, further prospective studies and clinical trials are warranted to provide reliable evidence of possible pitfalls and effectiveness of PRRNT and 68 Ga-somatostatin-receptor PET/CT in the management of MCC. (author)

  12. Enhanced Radiosensitivity of Tumor Cells Treated with Vanadate in Vitro

    International Nuclear Information System (INIS)

    Lee, Myung Za; Lee, Won Young

    1994-01-01

    tumor cells to radiation. Inhibitory effect of vanadate on Na+-K+-ATPase activity might be one of the contributing factors for radiosensitization to tumor cells which has greater enzyme activity than that of normal cell. It was suggested vanadate could be used as a potential radiosensitizer for tumor cells

  13. 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.)

  14. 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

  15. 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)

  16. 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

  17. Targeting neuroendocrine differentiation for prostate cancer radiosensitization

    Science.gov (United States)

    2017-12-01

    Fig. 12). Since we suspected that Western blotting-based method may not be sensitive enough, we are planning to use radioisotope -labeled SAM to...Chang-Deng Hu CONTRACTING ORGANIZATION: Purdue University, West Lafayette, IN 47907-2040 REPORT DATE : December 2017 TYPE OF REPORT: Final...RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE December 2017 2. REPORT TYPE Final 3. DATES COVERED 30 Sept 2013 - 29 Sept 2017 4. TITLE AND

  18. 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...

  19. 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)

  20. 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

  1. Investigation of radiosensitivity and growth dynamics for callus tissues Crepis Capillaris, Haplopappus gracilis, Phasolium vulgaris exposed to gamma radiation

    International Nuclear Information System (INIS)

    Gatsek, Eh.; Glinkova, E.; Ismailova, Eh.N.

    1983-01-01

    Radiosensitivity of three kinds of callus tissues (Crepis capillaris, Haplopappus gracilis, Phasolium vulgaris) manifested in the change of fresh weight after γ-irradiation has been investigated. Irradiated callus arowth showed decrease with increasing doses. It is shown that the radiosensitivity of ''young'' callus tissues is determined by the kind of the plant. Callus of Phaseolis has been found to have the highest radioresistance, while that of Crepis has the lowest one. Radiosensitivity of ''old'' callus tissues is the same for all kinds. Potential mechanism of radiosensitivity of callus tissUes are discussed

  2. Probabilistic delay differential equation modeling of event-related potentials.

    Science.gov (United States)

    Ostwald, Dirk; Starke, Ludger

    2016-08-01

    "Dynamic causal models" (DCMs) are a promising approach in the analysis of functional neuroimaging data due to their biophysical interpretability and their consolidation of functional-segregative and functional-integrative propositions. In this theoretical note we are concerned with the DCM framework for electroencephalographically recorded event-related potentials (ERP-DCM). Intuitively, ERP-DCM combines deterministic dynamical neural mass models with dipole-based EEG forward models to describe the event-related scalp potential time-series over the entire electrode space. Since its inception, ERP-DCM has been successfully employed to capture the neural underpinnings of a wide range of neurocognitive phenomena. However, in spite of its empirical popularity, the technical literature on ERP-DCM remains somewhat patchy. A number of previous communications have detailed certain aspects of the approach, but no unified and coherent documentation exists. With this technical note, we aim to close this gap and to increase the technical accessibility of ERP-DCM. Specifically, this note makes the following novel contributions: firstly, we provide a unified and coherent review of the mathematical machinery of the latent and forward models constituting ERP-DCM by formulating the approach as a probabilistic latent delay differential equation model. Secondly, we emphasize the probabilistic nature of the model and its variational Bayesian inversion scheme by explicitly deriving the variational free energy function in terms of both the likelihood expectation and variance parameters. Thirdly, we detail and validate the estimation of the model with a special focus on the explicit form of the variational free energy function and introduce a conventional nonlinear optimization scheme for its maximization. Finally, we identify and discuss a number of computational issues which may be addressed in the future development of the approach. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Radiosensitivity and chimera formation in Hibiscus syriacus

    International Nuclear Information System (INIS)

    Kwon, S.H.; Won, J.L.

    1980-01-01

    Radiosensitivity of gamma-irradiated Hibiscus syriacus and chimera formation were investigated. The lethal dose-50 percent with respect to seeding and cuttings was 15kR and 2 approximately 3 kR respectively, chlorophyll mutation rate of seeds irradiated with 15 kR being about 13 percent. The degree of chimeric leaf mutants from the buds by radiation treatment depends on the bud position of the branch. Buds of the middle part of V 1 branch seemed to be more multi-cellular condition than the upper and low part when irradiation was made. It is assumed that at least two primordia of V 2 branch were already differentiated from the V 1 branch in Hibiscus syriacus plant. (Author)

  4. Evaluation of nitrobenzimidazoles as hypoxic cell radiosensitizers

    International Nuclear Information System (INIS)

    Wright, J.; Frank, L.R.; Bush, D.; Harrison, G.H.

    1983-01-01

    Radiobiological and pharmacokinetic assays were performed to determine the potential of 2-nitrobenzimidazole (NBI) as a hypoxic cell radiosensitizing agent. As judged by comparing survival curve slopes of Serratia marcescens irradiated under aerated and hypoxic conditions, the NBI enhancement ratio (ER) at 2 mM concentration was 2.4 +- 0.2, compared with an oxygen enhancement ratio of 3.3 +- 0.3. 2,5-Dinitrobenzimidazole (DNBI) was investigated in vitro; its ER was 3.0 +- 0.3 at 4 mM concentration. Very poor tissue penetration of DNBI precluded further testing in vivo. Acute toxic signs appeared in C3H/HeJ mice following ip injection of NBI at 100 mg/kg. These would be partly attributable to the stress caused by the high pH of the injection vehicle. The LD 50 was estimated to be 125 to 150 mg/kg. Mammary adenocarcinoma tumors grown in the flanks of these mice exhibited maximum NBI levels at 5 min postinjection (ip). Peak tumor radiosensitization occurred in the interval between 5 and 10 min postinjection. The ER for tumor regrowth delay was 2.1 +- 0.3 following 50 mg/kg injected into mice 5 min before irradiation. Functional evaluation up to 40 days after treatment revealed no evidence of neurological deficit

  5. Evaluation of nitrobenzimidazoles as hypoxic cell radiosensitizers

    International Nuclear Information System (INIS)

    Wright, J.; Frank, L.R.; Bush, D.; Harrison, G.H.

    1983-01-01

    Radiobiological and pharmacokinetic assays were performed to determine the potential of 2-nitrobenzimidazole (NBI) as a hypoxic cell radiosensitizing agent. As judged by comparing survival curve slopes of Serratia marcescens irradiated under aerated and hypoxic conditions, the NBI enhancement ratio (ER) at 2 mM concentration was 2.4 +/- 0.2, compared with an oxygen enhancement ratio of 3.3 +/- 0.3. 2,5-Dinitrobenzimidazole (DNBI) was investigated in vitro; its ER was 3.0 +/- 0.3 at 4 mM concentration. Very poor tissue penetration of DNBI precluded further testing in vivo. Acute toxic signs appeared in C3H/HeJ mice following ip injection of NBI at 100 mg/kg. These would be partly attributable to the stress caused by the high pH of the injection vehicle. The LD50 was estimated to be 125-150 mg/kg. Mammary adenocarcinoma tumors grown in the flanks of these mice exhibited maximum NBI levels at 5 min postinjection (ip). Peak tumor radiosensitization occurred in the interval between 5 and 10 min postinjection. The ER for tumor regrowth delay was 2.1 +/- 0.3 following 50 mg/kg injected into mice 5 min before irradiation. Functional evaluation up to 40 days after treatment revealed no evidence of neurological deficit

  6. 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)

  7. 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)

  8. 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

  9. 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.

  10. 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.

  11. Radiosensitivity of garlic air bulbs

    International Nuclear Information System (INIS)

    Zhila, Eh.D.

    1975-01-01

    The paper presents data on the radiosensitivity of various sorts of garlic. It is shown that the frequency of chromosomal aberrations in the irradiated aerial bulbs of stemmed varieties of garlic is directly dependent upon the gmma-ray dose. With increasing dose the germination capacity and the viability of the plants diminishes. A dose of 750 r was found to be critical for the bulbs of the garlic varieties studied

  12. 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

  13. 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

  14. "Brain sex differentiation" in teleosts: Emerging concepts with potential biomarkers.

    Science.gov (United States)

    Senthilkumaran, Balasubramanian; Sudhakumari, Cheni-Chery; Mamta, Sajwan-Khatri; Raghuveer, Kavarthapu; Swapna, Immani; Murugananthkumar, Raju

    2015-09-01

    "Brain sex differentiation" in teleosts is a contentious topic of research as most of the earlier reports tend to suggest that gonadal sex differentiation drives brain sex differentiation. However, identification of sex-specific marker genes in the developing brain of teleosts signifies brain-gonadal interaction during early sexual development in lower vertebrates. In this context, the influence of gonadotropin-releasing hormone (GnRH)-gonadotropin (GTH) axis on gonadal sex differentiation, if any requires in depth analysis. Presence of seabream (sb) GnRH immunoreactivity (ir-) in the brain of XY Nile tilapia was found as early as 5days post hatch (dph) followed by qualitative reduction in the preoptic area-hypothalamus region. In contrast, in the XX female brain a steady ir- of sbGnRH was evident from 15dph. Earlier studies using sea bass already implied the importance of hypothalamic gonadotropic axis completion during sex differentiation period. Such biphasic pattern of localization was also seen in pituitary GTHs using heterologous antisera in tilapia. However, more recent analysis in the same species could not detect any sexually dimorphic pattern using homologous antisera for pituitary GTHs. Detailed studies on the development of hypothalamo-hypophyseal-gonadal axis in teleosts focusing on hypothalamic monoamines (MA) and MA-related enzymes demonstrated sex-specific differential expression of tryptophan hydroxylase (Tph) in the early stages of developing male and female brains of tilapia and catfish. The changes in Tph expression was in agreement with the levels of serotonin (5-HT) and 5-hydroxytryptophan in the preoptic area-hypothalamus. Considering the stimulatory influence of 5-HT on GnRH and GTH release, it is possible to propose a network association between these correlates during early development, which may bring about brain sex dimorphism in males. A recent study from our laboratory during female brain sex development demonstrated high expression of

  15. 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

  16. 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

  17. 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.

  18. 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

  19. 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)

  20. 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)

  1. 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.

  2. 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)

  3. Radiosensitivity of mesothelioma cell lines

    International Nuclear Information System (INIS)

    Haekkinen, A.M.; Laasonen, A.; Linnainmaa, K.; Mattson, K.; Pyrhoenen, S.

    1996-01-01

    The present study was carried out in order to examine the radiosensitivity of malignant pleural mesothelioma cell lines. Cell kinetics, radiation-induced delay of the cell cycle and DNA ploidy of the cell lines were also determined. For comparison an HeLa and a human foetal fibroblast cell line were simultaneously explored. Six previously cytogenetically and histologically characterized mesothelioma tumor cell lines were applied. A rapid tiazolyl blue microtiter (MTT) assay was used to analyze radiosensitivity and cell kinetics and DNA ploidy of the cultured cells were determined by flow cytometry. The survival fraction after a dose of 2 Gy (SF2), parameters α and β of the linear quadratic model (LQ-model) and mean inactivation dose (D MID ) were also estimated. The DNA index of four cell lines equaled 1.0 and two cell lines equaled 1.5 and 1.6. Different mesothelioma cell lines showed a great variation in radiosensitivity. Mean survival fraction after a radiation dose of 2 Gy (SF2) was 0.60 and ranged from 0.36 to 0.81 and mean α value was 0.26 (range 0.48-0.083). The SF2 of the most sensitive diploid mesothelioma cell line was 0.36: Less than that of the foetal fibroblast cell line (0.49). The survival fractions (0.81 and 0.74) of the two most resistant cell lines, which also were aneuploid, were equal to that of the HeLa cell line (0.78). The α/β ratios of the most sensitive cell lines were almost an order of magnitude greater than those of the two most resistant cell lines. Radiation-induced delay of the most resistant aneuploid cell line was similar to that of HeLa cells but in the most sensitive (diploid cells) there was practically no entry into the G1 phase following the 2 Gy radiation dose during 36 h. (orig.)

  4. Radiosensitization effects of nicotinamide on malignant and normal mouse tissue

    International Nuclear Information System (INIS)

    Jonsson, G.G.; Kjellen, E.; Pero, R.W.; Cameron, R.

    1985-01-01

    Inhibitors of the chromatin-associated enzyme adenosine diphosphate ribosyltransferase have been found to inhibit DNA strand rejoining and to potentiate lethality of DNA-damaging agents both in vivo and in vitro. The authors have in this work examined the radiosensitizing potential of one such inhibitor, nicotinamide, on tumor tissue by using transplanted C3H mouse mammary adenocarcinomas and on normal tissue in a tail-stunting experiment using BALB/cA mice. The data indicate a radiosensitizing effect of nicotinamide on tumor cells as well as on normal tissue. The data indicate a possible role of adenosine diphosphate ribosyltransferase inhibitors as a sensitizing agent in the radiotherapy of malignant tumors

  5. Melatonin as potential inducer of Th17 cell differentiation.

    Science.gov (United States)

    Kuklina, Elena M

    2014-09-01

    The subset of T lymphocytes producing IL-17 (Th17) plays a key role in the immune system. It has been implicated in host defense, inflammatory diseases, tumorigenesis, autoimmune diseases, and transplant rejection. Careful analysis of the data available holds that Th17 cell subpopulation should be under the direct control of pineal hormone melatonin: the key Th17 differentiation factor RORα serves in the meantime as a high-affinity melatonin receptor. Since the levels of melatonin have diurnal and seasonal variation, as well as substantial deviations in some physiological or pathological conditions, melatonin-dependent regulation of Th17 cells should implicate multiform manifestation, such as influencing the outcome of infectious challenge or determining predisposition, etiology and progression of immune-related morbidities. Another important reason to raise a point of the new melatonin effects is current considering the possibilities of its clinical trials. Especially, the differentiation of Th17 upon melatonin treatment must aggravate the current recession in autoimmune diseases or induce serious complications in pregnancy. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Isolation and Multiple Differentiation Potential Assessment of Human Gingival Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Yuan Gao

    2014-11-01

    Full Text Available The aim of this study was to isolate human mesenchymal stem cells (MSCs from the gingiva (GMSCs and confirm their multiple differentiation potentials, including the odontogenic lineage. GMSCs, periodontal ligament stem cells (PDLSCs and dermal stem cells (DSCs cultures were analyzed for cell shape, cell cycle, colony-forming unit-fibroblast (CFU-F and stem cell markers. Cells were then induced for osteogenic and adipogenic differentiation and analyzed for differentiation markers (alkaline phosphatase (ALP activity, mineralization nodule formation and Runx2, ALP, osteocalcin (OCN and collagen I expressions for the osteogenic differentiation, and lipid vacuole formation and PPARγ-2 expression for the adipogenic differentiation. Besides, the odontogenic differentiation potential of GMSCs induced with embryonic tooth germ cell-conditioned medium (ETGC-CM was observed. GMSCs, PDLSCs and DSCs were all stromal origin. PDLSCs showed much higher osteogenic differentiation ability but lower adipogenic differentiation potential than DSCs. GMSCs showed the medial osteogenic and adipogenic differentiation potentials between those of PDLSCs and DSCs. GMSCs were capable of expressing the odontogenic genes after ETGC-CM induction. This study provides evidence that GMSCs can be used in tissue engineering/regeneration protocols as an approachable stem cell source.

  7. 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)

  8. Intermolecular potential for Ar + D2O from differential scattering cross sections, and its implications for the water pair potential

    International Nuclear Information System (INIS)

    Brooks, R.; Porter, R.A.R.; Kalos, F.; Grosser, A.E.

    1975-01-01

    A velocity selected molecular beam of D 2 O was crossed with a nozzle beam of Ar and the angular distribution of the scattered D 2 O was measured mass spectrometrically. By varying the velocity of the D 2 O beam, the differential cross section was measured at two collision energies. The experimental results were compared with synthetic differential cross sections calculated from Lennard-Jones and Kihara-Stockmayer trial potentials to determine potential parameters. Implications for the H 2 O pair potential are discussed

  9. 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

  10. 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.

  11. The radiosensitivity of nile tilapia (Oreochromis niloticus) fingerlings

    International Nuclear Information System (INIS)

    Reyes, Michael Joseph T.; Velasco, Pia Victoria V.

    2000-04-01

    The nile tilapia (Oreochromis niloticus), a very popular fish commercially in the Philippines, was studied to determine its radiosensitivity and to see its potential as a biological indicator in aquatic ecosystems. Nile tilapia was seen to be radiosensitive. The fish were exposed to gamma-irradiation and chromosomal aberrations were induced. The various types of aberrations seen were chromatid gaps, chromosome gaps, chromatid fragments, dicentric rings, fusions, despiralizations and translocations. Among the aberrations observed, dicentric rings, fusions and chromosome gaps were strongly correlated with dosage, with only the dicentric rings increasing steadily with increasing dosage. In the course of the study, the lethal dosage 50 for nile tilapia with 18 days was determined and it was observed at 2.0 krad. The modal chromosome number was also established at 2n=44 with a karyotype exhibiting 22 pairs of acrocentric chromosomes with 2 pairs of marker chromosomes present. (Author)

  12. The radiosensitivity of nile tilapia (Oreochromis niloticus) fingerlings

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, Michael Joseph T; Velasco, Pia Victoria V

    2000-04-01

    The nile tilapia (Oreochromis niloticus), a very popular fish commercially in the Philippines, was studied to determine its radiosensitivity and to see its potential as a biological indicator in aquatic ecosystems. Nile tilapia was seen to be radiosensitive. The fish were exposed to gamma-irradiation and chromosomal aberrations were induced. The various types of aberrations seen were chromatid gaps, chromosome gaps, chromatid fragments, dicentric rings, fusions, despiralizations and translocations. Among the aberrations observed, dicentric rings, fusions and chromosome gaps were strongly correlated with dosage, with only the dicentric rings increasing steadily with increasing dosage. In the course of the study, the lethal dosage{sub 50} for nile tilapia with 18 days was determined and it was observed at 2.0 krad. The modal chromosome number was also established at 2n=44 with a karyotype exhibiting 22 pairs of acrocentric chromosomes with 2 pairs of marker chromosomes present. (Author)

  13. 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

  14. 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.

  15. 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...

  16. Nervous system disease associated with dominant cellular radiosensitivity

    International Nuclear Information System (INIS)

    Kidson, C.; Chen, P.; Imray, F.P.; Gipps, E.

    1983-01-01

    Ionizing radiation sensitivity has been demonstrated in the following neurological diseases: sporadic and familial Alzheimer's disease, familial non-specific dementia, amyotrophic lateral sclerosis and Parkinsonism dementia of Guam, Huntington's disease, multiple sclerosis. Family studies in many cases give data consistent with dominant genetics, as does cell fusion analysis in the one disease so studied. In no case was there an absolute association between radiosensitivity and a given neurological disease. It is proposed that the underlying mutations are in genes controlling facets of nervous or immune system differentiation and development. 15 references, 2 tables

  17. Effect of cisplatin on the clinically relevant radiosensitivity of human cervical carcinoma cell lines

    International Nuclear Information System (INIS)

    Britten, Richard A.; Evans, Andrew J.; Allalunis-Turner, M. Joan; Pearcey, Robert G.

    1996-01-01

    Purpose: To evaluate the effect of clinically relevant levels of cisplatin on the radiosensitivity of human cervical tumor cells, and to estimate what changes in local control rates might be expected to accrue from the concomitant use of cisplatin during fractionated radiotherapy. Methods and Materials: The effects of concomitant cisplatin (1 μg/ml, a typical intratumor concentration) on the clinically relevant radiosensitivity, i.e., surviving fraction after 2 G (SF 2 ) values, was determined in 19 cloned human cervical tumor cell lines. These early passage cell lines had SF 2 values ranging from 0.26 to 0.87. Results: The concomitant administration of cisplatin reduced the clinically relevant radiosensitivity in the majority (11 out of 19) of the human tumor cell lines investigated. In only 4 out of 19 was any radiosensitization observed, and in 4 out of 19 cell lines there was no significant change in radiosensitivity. However, the sum of the independent cell killing by radiation and cisplatin, was approximately twofold higher than after radiation alone. There was no apparent dependence of the cisplatin-induced changes in SF 2 values upon the level of cell killing by cisplatin. However, there is a suggestion that concomitant cisplatin administration may have a differential effect in inherently radiosensitive and resistant human tumor cell lines. Conclusions: Our data suggest that concomitant cisplatin/radiotherapy regimens may result in a higher level of local tumor control, but primarily through additive toxicity and not through radiosensitization. Future improvements in local tumor control may, thus, be derived by increasing the total dose of cisplatin

  18. Radiosensitivity of mesothelioma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Haekkinen, A.M. [Dept. of Oncology, Univ. Central Hospital, Helsinki (Finland); Laasonen, A. [Dept. of Pathology, Central Hospital of Etelae-Pohjanmaa, Seinaejoki (Finland); Linnainmaa, K. [Dept. of Industrial Hygiene and Toxicology, Inst. of Occupational Health, Helsinki (Finland); Mattson, K. [Dept. Pulmonary Medicine, Univ. Central Hospital, Helsinki (Finland); Pyrhoenen, S. [Dept. of Oncology, Univ. Central Hospital, Helsinki (Finland)

    1996-10-01

    The present study was carried out in order to examine the radiosensitivity of malignant pleural mesothelioma cell lines. Cell kinetics, radiation-induced delay of the cell cycle and DNA ploidy of the cell lines were also determined. For comparison an HeLa and a human foetal fibroblast cell line were simultaneously explored. Six previously cytogenetically and histologically characterized mesothelioma tumor cell lines were applied. A rapid tiazolyl blue microtiter (MTT) assay was used to analyze radiosensitivity and cell kinetics and DNA ploidy of the cultured cells were determined by flow cytometry. The survival fraction after a dose of 2 Gy (SF2), parameters {alpha} and {beta} of the linear quadratic model (LQ-model) and mean inactivation dose (D{sub MID}) were also estimated. The DNA index of four cell lines equaled 1.0 and two cell lines equaled 1.5 and 1.6. Different mesothelioma cell lines showed a great variation in radiosensitivity. Mean survival fraction after a radiation dose of 2 Gy (SF2) was 0.60 and ranged from 0.36 to 0.81 and mean {alpha} value was 0.26 (range 0.48-0.083). The SF2 of the most sensitive diploid mesothelioma cell line was 0.36: Less than that of the foetal fibroblast cell line (0.49). The survival fractions (0.81 and 0.74) of the two most resistant cell lines, which also were aneuploid, were equal to that of the HeLa cell line (0.78). The {alpha}/{beta} ratios of the most sensitive cell lines were almost an order of magnitude greater than those of the two most resistant cell lines. Radiation-induced delay of the most resistant aneuploid cell line was similar to that of HeLa cells but in the most sensitive (diploid cells) there was practically no entry into the G1 phase following the 2 Gy radiation dose during 36 h. (orig.).

  19. Potential differentiation of islet-like cells from pregnant cow-derived placental stem cells

    Directory of Open Access Journals (Sweden)

    Shao-Yu Peng

    2017-06-01

    Conclusion: Altogether, islet-like cells have the potential to be differentiated from CPSCs without gene manipulation, and can be used in diabetic animal models in the future for preclinical and drug testing trial investigations.

  20. Differentiating drugs by harm potential: the rational versus the feasible.

    Science.gov (United States)

    Kalant, H

    1999-01-01

    In an ideal harm reduction model, drugs would be ranked according to their potential to cause harm, with varying implications for control policies and interventions. In such a public health oriented approach, the maximum protection of the public from harm would be balanced with the least possible restriction of freedom. In reality, however, the accuracy and completeness of the necessary information for such a ranking is highly limited. Many other factors not readily incorporated in a rational model, such as values, beliefs, and traditions, also affect drug policy decisions. Thus, rather than relying on acquisition of the necessary knowledge, it may be preferable to focus efforts on developing effective nonlegal measures to reduce drug use and harm. [Translations are provided in the International Abstracts Section of this issue.

  1. Radiosensitivity of mouse germ cells

    International Nuclear Information System (INIS)

    Matsuda, Yoichi; Takeuchi, Toyoko; Maemori, Mamiko; Seki, Naohiko; Tobari, Izuo

    1991-01-01

    To estimate radiosensitivity of mouse germ cells the analysis of chromosome aberrations was performed at diakinesis-metaphase I of spermatocytes and first-cleavage metaphase of one-cell embryos after exposure to radiations at various stages of primary spermatocytes and spermatids. The result provided evidence that there are two major types of DNA damage in X-irradiated sperm : (1) short-lived DNA lesions ; the lesions are subject to repair inhibition by agents added in G 1 , and are converted into chromosome-type aberrations during G 1 , and (2) long-lived DNA lesions ; the lesions persist until S phase and repair of the lesions is inhibited by caffeine, hydroxyurea and arabinofuranosyl cytosine in G 2 . The characteristic of X-ray damage induced in spermiogenic stage and repair mechanism for the damage in the fertilized egg were discussed comparing with the results with two chemicals, methyl methanesulfonate (MMS) and mitomycin C (MMC). (J.P.N.)

  2. Radiosensitizing effect of nitric oxide in tumor cells and experimental tumors irradiated with gamma rays and proton beams

    International Nuclear Information System (INIS)

    Policastro, Lucia L.; Duran, Hebe; Molinari, Beatriz L.; Somacal, Hector R.; Valda, Alejandro A.

    2003-01-01

    Nitric oxide (NO) has been reported to be a radiosensitizer of mammalian cells under hypoxic conditions. In a previous study, we demonstrated an enhancement in radiation response induced by NO in mouse tumor cells under aerobic conditions, with an increasing effect as a function of malignancy. The aim of the present study was to evaluate the effect of NO in tumor cells and in experimental tumors irradiated with γ rays and proton beams. Irradiations were performed with a 137 Cs γ source and with proton beams generated by the TANDAR accelerator. Tumor cells were treated with the NO donor DETA-NO and the sensitizer enhancement ratio (SER) was calculated using the α parameter of the survival curve fitted to the linear-quadratic model. Tumor cells irradiated with protons were radio sensitized by DETA-NO only in the more malignant cells irradiated with low LET protons (2.69±0.08 keV/μm). For higher LET protons there were no radiosensitizing effect. For human tumor cells pre-treated with DETA-NO and irradiated with γ rays, a significantly greater effect was demonstrated in the malignant cells (MCF-7) as compared with the near normal cells (HBL-100). Moreover, a significant decrease in tumor growth was demonstrated in mice pre-treated with the NO donor spermine and irradiated with γ rays and low LET protons as compared with mice irradiated without pre-treatment with the NO donor. In conclusion, we demonstrated a differential effect of NO as a radiosensitizer of malignant cells, both with γ rays and low LET protons. This selectivity, coupled to the in vivo inhibition of tumor growth, is of great interest for the potential use of NO releasing agents in radiotherapy. (author)

  3. 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.

  4. 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)

  5. 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)

  6. The HSP90 Inhibitor Ganetespib Radiosensitizes Human Lung Adenocarcinoma Cells

    Directory of Open Access Journals (Sweden)

    Roberto Gomez-Casal

    2015-05-01

    Full Text Available The molecular chaperone HSP90 is involved in stabilization and function of multiple client proteins, many of which represent important oncogenic drivers in NSCLC. Utilization of HSP90 inhibitors as radiosensitizing agents is a promising approach. The antitumor activity of ganetespib, HSP90 inhibitor, was evaluated in human lung adenocarcinoma (AC cells for its ability to potentiate the effects of IR treatment in both in vitro and in vivo. The cytotoxic effects of ganetespib included; G2/M cell cycle arrest, inhibition of DNA repair, apoptosis induction, and promotion of senescence. All of these antitumor effects were both concentration- and time-dependent. Both pretreatment and post-radiation treatment with ganetespib at low nanomolar concentrations induced radiosensitization in lung AC cells in vitro. Ganetespib may impart radiosensitization through multiple mechanisms: such as down regulation of the PI3K/Akt pathway; diminished DNA repair capacity and promotion of cellular senescence. In vivo, ganetespib reduced growth of T2821 tumor xenografts in mice and sensitized tumors to IR. Tumor irradiation led to dramatic upregulation of β-catenin expression in tumor tissues, an effect that was mitigated in T2821 xenografts when ganetespib was combined with IR treatments. These data highlight the promise of combining ganetespib with IR therapies in the treatment of AC lung tumors.

  7. Misonidazole radiosensitization in vivo: A therapeutic gain by penicillin pretreatment

    International Nuclear Information System (INIS)

    Sheldon, P.W.; Clarke, C.; Dawson, K.B.; Simpson, W.; Simmons, D.J.C.; Adams, G.E.

    1984-01-01

    Because intestinal microflora have the potential to metabolize nitroimidazole compounds (possibly to toxic species), the authors investigated their influence on the pharmacological, neurotoxic and radiosensitizing properties of misonidazole (MIS) in mice. This was done by comparing the responses obtained in 'normal' mice to those obtained in mice whose microflora had been depleted by pretreatment for 7-14 days with penicillin (PEN) at the rate of 0.5g/1 of drinking water. Bacteriological studies showed this treatment to C57B1 mice eliminated more than 99% of the flora from the caeca and, furthermore, this efficacy of penicillin was not interfered with by MIS administered IP at 0.3mg/g between days 7-14. This pretreatment resulted not only in the elimination of the caecal flora, but also in an increase in the pharmacokinetic exposure to MIS, an increase in Lewis lung tumour radiosensitization by MIS and a decrease in MIS-induced neurotoxicity. The authors conclude pretreatment with PEN can give a therapeutic gain with MIS radiosensitization. Further, assuming no direct interaction between the PEN and MIS, these findings indicate that the intestinal flora may produce neurotoxic species by their metabolism of MIS

  8. 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)

  9. 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.)

  10. Hypoxia modulates the differentiation potential of stem cells of the apical papilla.

    Science.gov (United States)

    Vanacker, Julie; Viswanath, Aiswarya; De Berdt, Pauline; Everard, Amandine; Cani, Patrice D; Bouzin, Caroline; Feron, Olivier; Diogenes, Anibal; Leprince, Julian G; des Rieux, Anne

    2014-09-01

    Stem cells from the apical papilla (SCAP) are a population of mesenchymal stem cells likely involved in regenerative endodontic procedures and have potential use as therapeutic agents in other tissues. In these situations, SCAP are exposed to hypoxic conditions either within a root canal devoid of an adequate blood supply or in a scaffold material immediately after implantation. However, the effect of hypoxia on SCAP proliferation and differentiation is largely unknown. Therefore, the objective of this study was to evaluate the effect of hypoxia on the fate of SCAP. SCAP were cultured under normoxia (21% O2) or hypoxia (1% O2) in basal or differentiation media. Cellular proliferation, gene expression, differentiation, and protein secretion were analyzed by live imaging, quantitative reverse-transcriptase polymerase chain reaction, cellular staining, and enzyme-linked immunosorbent assay, respectively. Hypoxia had no effect on SCAP proliferation, but it evoked the up-regulation of genes specific for osteogenic differentiation (runt-related transcription factor 2, alkaline phosphatase, and transforming growth factor-β1), neuronal differentiation ( 2'-3'-cyclic nucleotide 3' phosphodiesterase, SNAIL, neuronspecific enolase, glial cell-derived neurotrophic factor and neurotrophin 3), and angiogenesis (vascular endothelial growth factor A and B). Hypoxia also increased the sustained production of VEGFa by SCAP. Moreover, hypoxia augmented the neuronal differentiation of SCAP in the presence of differentiation exogenous factors as detected by the up-regulation of NSE, VEGFB, and GDNF and the expression of neuronal markers (PanF and NeuN). This study shows that hypoxia induces spontaneous differentiation of SCAP into osteogenic and neurogenic lineages while maintaining the release of the proangiogenic factor VEGFa. This highlights the potential of SCAP to promote pulp-dentin regeneration. Moreover, SCAP may represent potential therapeutic agents for neurodegenerative

  11. 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

  12. 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

  13. Radiosensitivity in cultured human fibroblasts

    International Nuclear Information System (INIS)

    Cox, R.; Masson, W.K.

    1980-01-01

    Caution is urged in the use of freshly isolated cultures of human diploid fibroblasts for quantitative studies of radiosensitivity. The distribution of x ray sensitivities of 'normal' human fibroblast cultures of foetal origin (10 subjects, skin or lung biopsy) and post-foetal origin (34 subjects, skin biopsy) are compared with the distribution in 12 patients with ataxia telangiectasia (probability of including any one of these in a normal post-foetal distribution is 0.01%). Cultures from nominally normal subjects showed a broad distribution of D 0 range of 98 +- 160 rad and assuming normal distribution, a mean +- one standard deviation of 122 +- 17 rad. Mean D 0 values for foetal origin cultures were 117 +- 12; values for post-foetal cultures D 0 were 124 +- 18. No systematic variation in D 0 was observed for age of donor, number of cell divisions in culture or for cloning efficiency. For ataxia telangiectasia D 0 values were 46 +- 7 rad. (U.K.)

  14. DNA damage repair and radiosensitivity

    International Nuclear Information System (INIS)

    Suzuki, Norio

    2003-01-01

    Tailored treatment is not new in radiotherapy; it has been the major subject for the last 20-30 years. Radiation responses and RBE (relative biological effectiveness) depend on assay systems, endpoints, type of tissues and tumors, radiation quality, dose rate, dose fractionation, physiological and environmental factors etc, Latent times to develop damages also differ among tissues and endpoints depending on doses and radiation quality. Recent progress in clarification of radiation induced cell death, especially of apoptotic cell death, is quite important for understanding radiosensitivity of tumor cure process as well as of tumorigenesis. Apoptotic cell death as well as dormant cells had been unaccounted and missed into a part of reproductive cell death. Another area of major progress has been made in clarifying repair mechanisms of radiation damage, i.e., non-homologous end joining (NHEJ) and homologous recombinational repair (HRR). New approaches and developments such as cDNA or protein micro arrays and so called informatics in addition to basic molecular biological analysis are expected to aid identifying molecules and their roles in signal transduction pathways, which are multi-factorial and interactive each other being involved in radiation responses. (authors)

  15. Effect of hypothermia on radiosensitization

    International Nuclear Information System (INIS)

    Nias, A.H.W.; Perry, P.; Photiou, A.; Reghebi, K.

    1986-01-01

    The blood supply and oxygen tension have been measured in C3H mouse mammary tumours under hypothermia and hyperbaric oxygen, and the enhancement of radiosensitivity by hyperbaric oxygen has been estimated in mice irradiated at different temperatures with and without anaesthesia. Measurement of xenon-133 clearance showed that the blood supply of a tumour tended to increase when anaesthetized mice became hypothermic. Oxygen cathode data showed that the oxygen tension tended to be relatively higher in tumours and lower in subcutaneous tissue when mice exposed to hyperbaric oxygen became hypothermic under anaesthesia. Hyperbaric oxygen enhanced the radiation response of the tumour in terms of an increase in regrowth delay by a factor of 1.7 when the mice had been anaesthetized, whether or not they became hypothermic. A lower factor of 1.4 was obtained without anaesthesia although induced hypothermia increased the response to a small extent. The authors conclude that anaesthesia and hypothermia affect oxygen metabolism in tumours by different mechanisms. (author)

  16. 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

  17. 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)

  18. Radiosensitivity of glial progenitor cells of the perinatal and adult rat optic nerve studied by an in vitro clonogenic assay

    International Nuclear Information System (INIS)

    Maazen, R.W.M. van der; Verhagen, I.; Kleiboer, B.J.; Kogel, A.J. van der

    1991-01-01

    The cellular basis of radiation-induced demyelination and white matter necrosis of the central nervous system (CNS), is poorly understood. Glial cells responsible for myelination in the CNS might be the target cells of this type of damage. Glial cells with stem cell properties derived from the perinatal and adult rat CNS can be cultured in vitro. These cells are able to differentiate into oligodendrocytes or type-2 astrocytes (O-2A) depending on the culture conditions. Growth factors produced by monolayers of type-1 astrocytes inhibit premature differentiation of O-2A progenitor cells and allow colony formation. A method which employs these monolayers of type-1 astrocytes to culture O-2A progenitor cells has been adapted to allow the analysis of colonies of surviving cells after X-irradiation. In vitro survival curves were obtained for glial progenitor cells derived from perinatal and adult optic nerves. The intrinsic radiosensitivity of perinatal and adult O-2A progenitor cells showed a large difference. Perinatal O-2A progenitor cells are quite radiosensitive, in contrast to adult O-2A progenitor cells. For both cell types an inverse relationship was found between the dose and the size of colonies derived from surviving cells. Surviving O-2A progenitor cells maintain their ability to differentiate into oligo-dendrocytes or type-2 astrocytes. This system to assess radiation-induced damage to glial progenitor cells in vitro systems to have a great potential in unraveling the cellular basis of radiation-induced demyelinating syndromes of the CNS. (author). 28 refs.; 4 figs.; 1 tab

  19. Integrin inhibitor (Cilengitide) as radiosensitization strategy for malignant tumors

    International Nuclear Information System (INIS)

    Silva, Felipe Henrique de Souza

    2017-01-01

    Radiotherapy is effective in tumor control, but several tumors have molecular characteristics that lead to radioresistance and possible posttreatment recurrence. Many tumors have overexpression of integrin receptors. Integrins play a central role in growth, motility, regulation of adhesion and survival, leading to increased proliferation, invasion and metastasis of tumors, making these receptors excellent targets for the development of new therapies. Studies have shown that inhibiting the interaction of matrix proteins with integrin receptors may increase the cytotoxic effect of ionizing radiation by demonstrating the radiosensitizing potential of combination therapy in tumoral lines. Cilengitide an inhibitor of integrins receptors α Vβ3 and αVβ5 stands out for its great antitumor potential against gliomas. Thus, the combination of ionizing radiation with cilengitide is an alternative therapeutic strategy. However, the effect of this combination is little studied in Glioblastomas (U87 and T98) and not studied in melanoma (UACC). The objective of this study was to evaluate the radiosensitising potential of the RGD molecule cilengitida by means of the combined treatment with gamma radiation in different tumor lines, as well as to compare the effect of this combination therapy with cisplatin, a molecule already used in clinical practice. Our panel of tumor cell lines was composed of U87 (wild-type p53 malignant glioblastoma) T98 (malignant glioblastoma mutant p53), MCF7 (mammary carcinoma) and UACC (melanoma). The radiosensitizer effect of cilengitide was evaluated by the quantification of metabolic cell viability through the MTT assay. Inhibition of colony formation was investigated in clonogenicity assays. The flow cytometer was used to investigate cell cycle distribution and the type of cell death induced. We observed that in all cell lines examined, cilengitida promoted detachment, metabolic alterations and reduction of proliferation, as well as alteration of

  20. Morphology-based prediction of osteogenic differentiation potential of human mesenchymal stem cells.

    Directory of Open Access Journals (Sweden)

    Fumiko Matsuoka

    Full Text Available Human bone marrow mesenchymal stem cells (hBMSCs are widely used cell source for clinical bone regeneration. Achieving the greatest therapeutic effect is dependent on the osteogenic differentiation potential of the stem cells to be implanted. However, there are still no practical methods to characterize such potential non-invasively or previously. Monitoring cellular morphology is a practical and non-invasive approach for evaluating osteogenic potential. Unfortunately, such image-based approaches had been historically qualitative and requiring experienced interpretation. By combining the non-invasive attributes of microscopy with the latest technology allowing higher throughput and quantitative imaging metrics, we studied the applicability of morphometric features to quantitatively predict cellular osteogenic potential. We applied computational machine learning, combining cell morphology features with their corresponding biochemical osteogenic assay results, to develop prediction model of osteogenic differentiation. Using a dataset of 9,990 images automatically acquired by BioStation CT during osteogenic differentiation culture of hBMSCs, 666 morphometric features were extracted as parameters. Two commonly used osteogenic markers, alkaline phosphatase (ALP activity and calcium deposition were measured experimentally, and used as the true biological differentiation status to validate the prediction accuracy. Using time-course morphological features throughout differentiation culture, the prediction results highly correlated with the experimentally defined differentiation marker values (R>0.89 for both marker predictions. The clinical applicability of our morphology-based prediction was further examined with two scenarios: one using only historical cell images and the other using both historical images together with the patient's own cell images to predict a new patient's cellular potential. The prediction accuracy was found to be greatly enhanced

  1. Surface potential-governed cellular osteogenic differentiation on ferroelectric polyvinylidene fluoride trifluoroethylene films.

    Science.gov (United States)

    Tang, Bolin; Zhang, Bo; Zhuang, Junjun; Wang, Qi; Dong, Lingqing; Cheng, Kui; Weng, Wenjian

    2018-05-02

    Surface potential of biomaterials can dramatically influence cellular osteogenic differentiation. In this work, a wide range of surface potential on ferroelectric polyvinylidene fluoride trifluoroethylene (P(VDF-TrFE)) films was designed to get insight into the interfacial interaction of cell-charged surface. The P(VDF-TrFE) films poled by contact electric poling at various electric fields obtained well stabilized surface potential, with wide range from -3 to 915 mV. The osteogenic differentiation level of cells cultured on the films was strongly dependent on surface potential and reached the optimum at 391 mV in this system. Binding specificity assay indicated that surface potential could effectively govern the binding state of the adsorbed fibronectin (FN) with integrin. Molecular dynamic (MD) simulation further revealed that surface potential brought a significant difference in the relative distance between RGD and synergy PHSRN sites of adsorbed FN, resulting in a distinct integrin-FN binding state. These results suggest that the full binding of integrin α5β1 with both RGD and PHSRN sites of FN possesses a strong ability to activate osteogenic signaling pathway. This work sheds light on the underlying mechanism of osteogenic differentiation behavior on charged material surfaces, and also provides a guidance for designing a reasonable charged surface to enhance osteogenic differentiation. The ferroelectric P(VDF-TrFE) films with steady and a wide range of surface potential were designed to understand underlying mechanism of cell-charged surface interaction. The results showed that the charged surface well favored upregulation of osteogenic differentiation of MC3T3-E1 cells, and more importantly, a highest level occurred on the film with a moderate surface potential. Experiments and molecular dynamics simulation demonstrated that the surface potential could govern fibronectin conformation and then the integrin-fibronectin binding. We propose that a full binding

  2. 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

  3. Current View on Osteogenic Differentiation Potential of Mesenchymal Stromal Cells Derived from Placental Tissues.

    Science.gov (United States)

    Kmiecik, Gabriela; Spoldi, Valentina; Silini, Antonietta; Parolini, Ornella

    2015-08-01

    Mesenchymal stromal cells (MSC) isolated from human term placental tissues possess unique characteristics, including their peculiar immunomodulatory properties and their multilineage differentiation potential. The osteogenic differentiation capacity of placental MSC has been widely disputed, and continues to be an issue of debate. This review will briefly discuss the different MSC populations which can be obtained from different regions of human term placenta, along with their unique properties, focusing specifically on their osteogenic differentiation potential. We will present the strategies used to enhance osteogenic differentiation potential in vitro, such as through the selection of subpopulations more prone to differentiate, the modification of the components of osteo-inductive medium, and even mechanical stimulation. Accordingly, the applications of three-dimensional environments in vitro and in vivo, such as non-synthetic, polymer-based, and ceramic scaffolds, will also be discussed, along with results obtained from pre-clinical studies of placental MSC for the regeneration of bone defects and treatment of bone-related diseases.

  4. 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)

  5. 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

  6. Understanding the radiosensitivity of hematopoietic stem cells through CDNA micro-arrays profiling

    Energy Technology Data Exchange (ETDEWEB)

    Pawlik, A.; Cebo, Ch.; Vaigot, P.; Tronik-Le Roux, D. [Evry Univ., Lab. de Genomique et Radiobiologie de l' Hematopoiese, Service de Genomique Fonctionnelle, CEA, 91 (France)

    2006-07-01

    individually, since a large percentage of the identified genes have not been yet attributed to a particular function. To determine whether expression modulations of these genes could be associated with changes in the cell radiosensitivity, we have constructed vectors containing either cDNA s encoding four transcription factors or specific siRNA. Transfections in different cell lines are currently performed to assess whether overexpression or inhibition o f these factors might modify the radiosensitivity of the cell. To determine whether the in vivo transcriptional changes in gene expression triggered by ionizing radiation exposure were dependent on the microenvironment, the effect of IR exposure was monitored in the murine E.M.L. cell line. These cells were defined as possessing a Sca 'B220{sup -} Lin{sup lo} stem-like phenotype and can be potentially differentiated onto both lymphoid and myeloid lineages. Similarities of the in vivo and in vitro responses might be considered mostly as cell autonomous. Altogether this approach has the potential for unraveling molecular networks and finding novel and specific actors participating to the early response o f hematopoietic cells to radiation exposure. The outcome of this research might lead to the identification of molecules that ultimately modify the radiosensitivity of a cell and facilitate the derivation of clinically useful targets for rational therapeutic decisions. (N.C.)

  7. Radiosensitization, mutagenicity, and toxicity of Escherichia coli by several nitrofurans and nitroimidazoles. [X radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chessin, H.; McLaughlin, T.; Mroczkowski, Z.; Rupp, W.D.; Low, K.B.

    1978-08-01

    Representative nitrofurans (nitrofurantoin, nifuroxime, NF-167, NF-269) and nitroimidazoles (metronidazole, misonidazole) were found to sensitize hypoxic RecA/sup -/ Escherichia coli cells to X irradiation. These compounds were also mutagenic to E. coli using a UvrA/sup -/ strain as a test system, and toxic at high concentrations, using several strains differing in their repair capacity. However, the relative degrees of radiosensitization, mutagenicity, and toxicity, for the various compounds, were not simply correlated, suggesting that potential radiosensitizers with fewer side effects could be screened using bacteria.

  8. Hypoxia, Radiosensitizers and high-LET radiation - Nimorazole fragmentation using mass spectrometry

    DEFF Research Database (Denmark)

    Feketeova, Linda; Bassler, Niels

    (s): Fragmentation experiments have been performed using a Finnigan- LTQ-FT mass spectrometer equipped with an electrospray ionisation source. Collision-induced dissociation (CID) and electron-induced dissociation (EID) have been carried out by mass selecting the desired ions and subjecting them to activation energy...... using mass spectrometry. Understanding the fragmentation of radiosensitizers is crucial in evaluating the radiosensitization potential and developing new and more effective drugs, which may improve TCP in hypoxic tumours when using ion beams such as carbon-12 along with LET-painting techniques. Method...

  9. Chromosome aberrations in human lymphocytes for investigation of individual radiosensitivity

    International Nuclear Information System (INIS)

    Zitzelsberger, H.; Bauchinger, M.

    2000-01-01

    Stable translocations and insertions which are not selected against during cell proliferation can be reliably scored by use of fluorescence in situ hybridisation (FISH) which allows painting of selected chromosomes along their entire length. This temporal persistence makes them particulary valuable for quantifying post human radiation exposures ('biodosimetry'). A disadvantage of this approach is that for routine use only a partial genome analysis can be performed which is mostly based on triple combinations of DNA probes for particular chromosomes. Translocation frequencies from partial genome analysis are often scaled-up to equal the full genome. Basic assumptions for such scaling are, that double strand breaks leading to translocations must be distributed randomly throughout the genome and no preferential interaction between particular pairs of chromosomes occurs. Thus, the probability of a particular chromosome being involved in an exchange is proportional to its DNA content. However, this is not always supported by experimental findings and may thus indicate a differential radiosensitivity of particular chromosomes. Translocation measurements in peripheral blood of different healthy donors irradiated in vitro with the same dose revealed also some evidence for the existence of interindividual differences in radiosensitivity. Similar findings have been already demonstrated after therapeutic irradiation of tumour patients. Consequences thereof may result for long-term retrospective biodosimetry. In order to provide reliable estimates of an individual's exposure to ionising radiation, the extent, distribution and dose-dependence of the observed variability has to be carefully examined in larger groups of persons and larger sets of calibration data. (orig.) [de

  10. Is variation in human radiosensitivity real or artifactual?

    International Nuclear Information System (INIS)

    Nakamura, Nori; Kushiro, Jun-ichi; Sposto, R.; Akiyama, Mitoshi.

    1989-12-01

    Two methods of producing human T-lymphocyte colonies in vitro are described, as well as dose-survival experiments using these methods for the investigation of possible differential radiosensitivity among individuals. In one method, the cloning efficiency (CE) of nonirradiated lymphocytes was between 10 % and 40 % (method 1), whereas subsequent improvement in assay conditions (method 2) resulted in a CE greater than 30 %. In vitro X-irradiation of colonies produced using method 1 revealed that the dose required to kill 90 % of the cells (D 10 ) was 2.87±0.28 Gy (mean ±SD, n = 18) for repeated examinations of lymphocytes from one reference individual. Using method 2, the D 10 values were greater, viz., 3.66±0.21 Gy for 28 repeated tests of the same reference individual and 3.58±0.19 Gy for 31 different individuals. Analysis of variance to compare the data from repeated examinations of one person versus data from single examinations of different persons showed that variation in the D 10 value was not significantly greater in the latter group. These results support the hypothesis that individual variation in human radiosensitivity is quite small, if it exists at all, as far as can be determined by the loss of colony-forming ability of irradiated G 0 lymphocytes. (author)

  11. LET effects on normal and radiosensitive cell lines

    International Nuclear Information System (INIS)

    Geard, C.R.; Travisano, M.

    1986-01-01

    Charged particles in the track segment mode were produced by the RARAF Van de Graaff accelerator and used to irradiate two CHO cell lines, a radiosensitive hypermutable line EM9 and its normal parent AA8. Asynchronous cells were irradiated attached to 6 micrometer thick Mylar with protons, deuterons and helium-3 particles at LETs ranging from 10 to 150 keV per micrometer. A 50 kVp x-ray tube integrated into the track segment facility provided a low LET comparison. Following irradiation cells were monitored for clonogenicity, and in a separate series of experiments frequencies of sister chromatid exchanges. Up to 9 experiments were carried out at each LET, with a total of 8 radiations of different LETs being compared. The optimally effective LET for cell survival was between 80 and 120 keV per micrometer, with the 150 keV per micrometer particles indicating energy wastage. The differential between the normal and radiosensitive cell lines was maintained at all LETs

  12. 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

  13. Expansion of Adult Human Pancreatic Tissue Yields Organoids Harboring Progenitor Cells with Endocrine Differentiation Potential

    Directory of Open Access Journals (Sweden)

    Cindy J.M. Loomans

    2018-03-01

    Full Text Available Summary: Generating an unlimited source of human insulin-producing cells is a prerequisite to advance β cell replacement therapy for diabetes. Here, we describe a 3D culture system that supports the expansion of adult human pancreatic tissue and the generation of a cell subpopulation with progenitor characteristics. These cells display high aldehyde dehydrogenase activity (ALDHhi, express pancreatic progenitors markers (PDX1, PTF1A, CPA1, and MYC, and can form new organoids in contrast to ALDHlo cells. Interestingly, gene expression profiling revealed that ALDHhi cells are closer to human fetal pancreatic tissue compared with adult pancreatic tissue. Endocrine lineage markers were detected upon in vitro differentiation. Engrafted organoids differentiated toward insulin-positive (INS+ cells, and circulating human C-peptide was detected upon glucose challenge 1 month after transplantation. Engrafted ALDHhi cells formed INS+ cells. We conclude that adult human pancreatic tissue has potential for expansion into 3D structures harboring progenitor cells with endocrine differentiation potential. : In the context of β cell replacement therapy for diabetes, de Koning and colleagues describe a 3D culture platform that supports ex vivo expansion of human pancreatic tissue as organoids. These organoids harbor a subpopulation of ALDHhi cells that display proliferative capacity and can differentiate to an endocrine fate. Keywords: pancreas, organoid, human, ALDH, endocrine differentiation, beta cells, insulin, progenitor, fetal, diabetes

  14. Potential Effect of CD271 on Human Mesenchymal Stromal Cell Proliferation and Differentiation

    Directory of Open Access Journals (Sweden)

    Giovanna Calabrese

    2015-07-01

    Full Text Available The Low-Affinity Nerve Growth Factor Receptor (LNGFR, also known as CD271, is a member of the tumor necrosis factor receptor superfamily. The CD271 cell surface marker defines a subset of multipotential mesenchymal stromal cells and may be used to isolate and enrich cells derived from bone marrow aspirate. In this study, we compare the proliferative and differentiation potentials of CD271+ and CD271− mesenchymal stromal cells. Mesenchymal stromal cells were isolated from bone marrow aspirate and adipose tissue by plastic adherence and positive selection. The proliferation and differentiation potentials of CD271+ and CD271− mesenchymal stromal cells were assessed by inducing osteogenic, adipogenic and chondrogenic in vitro differentiation. Compared to CD271+, CD271− mesenchymal stromal cells showed a lower proliferation rate and a decreased ability to give rise to osteocytes, adipocytes and chondrocytes. Furthermore, we observed that CD271+ mesenchymal stromal cells isolated from adipose tissue displayed a higher efficiency of proliferation and trilineage differentiation compared to CD271+ mesenchymal stromal cells isolated from bone marrow samples, although the CD271 expression levels were comparable. In conclusion, these data show that both the presence of CD271 antigen and the source of mesenchymal stromal cells represent important factors in determining the ability of the cells to proliferate and differentiate.

  15. Potential Effect of CD271 on Human Mesenchymal Stromal Cell Proliferation and Differentiation.

    Science.gov (United States)

    Calabrese, Giovanna; Giuffrida, Raffaella; Lo Furno, Debora; Parrinello, Nunziatina Laura; Forte, Stefano; Gulino, Rosario; Colarossi, Cristina; Schinocca, Luciana Rita; Giuffrida, Rosario; Cardile, Venera; Memeo, Lorenzo

    2015-07-09

    The Low-Affinity Nerve Growth Factor Receptor (LNGFR), also known as CD271, is a member of the tumor necrosis factor receptor superfamily. The CD271 cell surface marker defines a subset of multipotential mesenchymal stromal cells and may be used to isolate and enrich cells derived from bone marrow aspirate. In this study, we compare the proliferative and differentiation potentials of CD271+ and CD271- mesenchymal stromal cells. Mesenchymal stromal cells were isolated from bone marrow aspirate and adipose tissue by plastic adherence and positive selection. The proliferation and differentiation potentials of CD271+ and CD271- mesenchymal stromal cells were assessed by inducing osteogenic, adipogenic and chondrogenic in vitro differentiation. Compared to CD271+, CD271- mesenchymal stromal cells showed a lower proliferation rate and a decreased ability to give rise to osteocytes, adipocytes and chondrocytes. Furthermore, we observed that CD271+ mesenchymal stromal cells isolated from adipose tissue displayed a higher efficiency of proliferation and trilineage differentiation compared to CD271+ mesenchymal stromal cells isolated from bone marrow samples, although the CD271 expression levels were comparable. In conclusion, these data show that both the presence of CD271 antigen and the source of mesenchymal stromal cells represent important factors in determining the ability of the cells to proliferate and differentiate.

  16. Gene expression profiling reveals new potential players of gonad differentiation in the chicken embryo.

    Directory of Open Access Journals (Sweden)

    Gwenn-Aël Carré

    Full Text Available BACKGROUND: In birds as in mammals, a genetic switch determines whether the undifferentiated gonad develops into an ovary or a testis. However, understanding of the molecular pathway(s involved in gonad differentiation is still incomplete. METHODOLOGY/PRINCIPAL FINDINGS: With the aim of improving characterization of the molecular pathway(s involved in gonad differentiation in the chicken embryo, we developed a large scale real time reverse transcription polymerase chain reaction approach on 110 selected genes for evaluation of their expression profiles during chicken gonad differentiation between days 5.5 and 19 of incubation. Hierarchical clustering analysis of the resulting datasets discriminated gene clusters expressed preferentially in the ovary or the testis, and/or at early or later periods of embryonic gonad development. Fitting a linear model and testing the comparisons of interest allowed the identification of new potential actors of gonad differentiation, such as Z-linked ADAMTS12, LOC427192 (corresponding to NIM1 protein and CFC1, that are upregulated in the developing testis, and BMP3 and Z-linked ADAMTSL1, that are preferentially expressed in the developing ovary. Interestingly, the expression patterns of several members of the transforming growth factor β family were sexually dimorphic, with inhibin subunits upregulated in the testis, and bone morphogenetic protein subfamily members including BMP2, BMP3, BMP4 and BMP7, upregulated in the ovary. This study also highlighted several genes displaying asymmetric expression profiles such as GREM1 and BMP3 that are potentially involved in different aspects of gonad left-right asymmetry. CONCLUSION/SIGNIFICANCE: This study supports the overall conservation of vertebrate sex differentiation pathways but also reveals some particular feature of gene expression patterns during gonad development in the chicken. In particular, our study revealed new candidate genes which may be potential actors

  17. Gene Expression Profiling Reveals New Potential Players of Gonad Differentiation in the Chicken Embryo

    Science.gov (United States)

    Carré, Gwenn-Aël; Couty, Isabelle; Hennequet-Antier, Christelle; Govoroun, Marina S.

    2011-01-01

    Background In birds as in mammals, a genetic switch determines whether the undifferentiated gonad develops into an ovary or a testis. However, understanding of the molecular pathway(s) involved in gonad differentiation is still incomplete. Methodology/Principal Findings With the aim of improving characterization of the molecular pathway(s) involved in gonad differentiation in the chicken embryo, we developed a large scale real time reverse transcription polymerase chain reaction approach on 110 selected genes for evaluation of their expression profiles during chicken gonad differentiation between days 5.5 and 19 of incubation. Hierarchical clustering analysis of the resulting datasets discriminated gene clusters expressed preferentially in the ovary or the testis, and/or at early or later periods of embryonic gonad development. Fitting a linear model and testing the comparisons of interest allowed the identification of new potential actors of gonad differentiation, such as Z-linked ADAMTS12, LOC427192 (corresponding to NIM1 protein) and CFC1, that are upregulated in the developing testis, and BMP3 and Z-linked ADAMTSL1, that are preferentially expressed in the developing ovary. Interestingly, the expression patterns of several members of the transforming growth factor β family were sexually dimorphic, with inhibin subunits upregulated in the testis, and bone morphogenetic protein subfamily members including BMP2, BMP3, BMP4 and BMP7, upregulated in the ovary. This study also highlighted several genes displaying asymmetric expression profiles such as GREM1 and BMP3 that are potentially involved in different aspects of gonad left-right asymmetry. Conclusion/Significance This study supports the overall conservation of vertebrate sex differentiation pathways but also reveals some particular feature of gene expression patterns during gonad development in the chicken. In particular, our study revealed new candidate genes which may be potential actors of chicken gonad

  18. Selective isolation and differentiation of a stromal population of human embryonic stem cells with osteogenic potential

    DEFF Research Database (Denmark)

    Harkness, Linda M; Mahmood, Amer; Ditzel, Nicholas

    2011-01-01

    cultured in osteogenic differentiation media, up regulation of osteoblastic lineage markers (DLX5, MSX2, RUNX2, SPARC, ALP, COL1a1, BGLAP, IBSP, DCN, LOX-L4) and production of in vitro mineralized matrix was detected. hESC-stromal cells loaded on a carrier and implanted either subcutaneously...... or in a critical size calvarial defect in immune deficient mice for 10weeks, resulted in new bone formation and partial repair of the calvarial defect. In conclusion, hESC-stromal can be isolated from hESC cultures and represent a good source for obtaining cells with osteogenic differentiation potential suitable...

  19. Preferential radiosensitization of G1 checkpoint--deficient cells by methylxanthines

    International Nuclear Information System (INIS)

    Russell, Kenneth J.; Wiens, Linda W.; Demers, G. William; Galloway, Denise A.; Le, Tiep; Rice, Glenn C.; Bianco, James A.; Singer, Jack W.; Groudine, Mark

    1996-01-01

    Purpose: To develop a checkpoint-based strategy for preferential radiosensitization of human tumors with deficient and/or mutant p53. Methods and Materials: A549 human lung adenocarcinoma cell lines differing in their expression of the p53 tumor suppressor gene were produced by transduction with the E6 oncogene from human papilloma virus type 16. The cells expressing E6 (E6+) lack a G1 arrest in response to ionizing radiation, are deficient in p53 and p21 expression, and exhibit a fivefold greater clonogenic survival following 10 Gy radiation. Results: Postirradiation incubation with millimolar concentrations of the methylxanthine pentoxifylline (PTX) results in preferential radiosensitization of the E6+ cells compared to the LXSN+ vector transduced controls. There is a threefold sensitization of the LXSN+ cells and a 15-fold sensitization of the E6+ cells, which results in equal clonogenic survival of the two lines. Flow cytometry reveals PTX abrogation of the radiation induced G2 arrest for both cell lines. PTX also prolongs G1 transit for both cell lines. Preliminary results are presented using a novel methylxanthine, lisofylline (LSF), which has similar cell cycle effects on G1 and G2 and achieves differential radiosensitization at micromolar concentrations that are sustainable in humans. Conclusions: This checkpoint-based strategy is a promising approach for achieving preferential radiosensitization of p53- tumors relative to p53+ normal tissues

  20. Different radiosensitivities of mast-cell precursors in the bone marrow and skin of mice

    International Nuclear Information System (INIS)

    Kitamura, Y.; Yokoyama, M.; Sonoda, T.; Mori, K.J.

    1983-01-01

    Although tissue mast cells are derived from the bone marrow, some descendants of bone marrow-derived precursors retain the ability to proliferate and differentiate into mast cells even after localization in the skin. The purpose of the present study was to determine the D0 values for mast-cell precursors in the bone marrow and those localized in the skin. Bone marrow cells were removed from (WB X C57BL/6)F1-+/+ mice after various doses of irradiation and injected into the skin of the congenic W/Wv mice which were genetically without mast cells. Radiosensitivity of mast-cell precursors in the bone marrow was evaluated by determining the proportion of the injection sites at which mast cells did not appear. For the assay of the radiosensitivity of mast-cell precursors localized in the skin, pieces of skin were removed from beige C57BL/6 (bgJ/bgJ. Chediak-Higashi syndrome) mice after various doses of irradiation and grafted onto the back of the normal C57BL/6 mice. Radiosensitivity of mast-cell precursors in the skin was evaluated by determining the decrease of beige-type mast cells which possessed giant granules. Mast-cell precursors in the bone marrow were much more radiosensitive than those localized in the skin. D0 value was about 100 rad for the former and about 800 rad for the latter

  1. Comparison of radiosensitivity between tumor and normal tissue in terms of cell population kinetics

    International Nuclear Information System (INIS)

    Sugahara, Tsutomu; Utsumi, Hiroshi

    1975-01-01

    Puck and Marcus in 1956 established the in vitro colony formation of mammalian cells and demonstrated a dose-survival curve of mammalian cells well fitted to the target theory. Since then almost all of the work on the radiosensitivity of malignant and normal cells has been based on the reproductive integrity of cells. However, in the author's laboratory, a recent work was done on the effect of ionizing radiation on the differentiative trait, using clonal cell cultures developed by Coon (1966) in chick embryonic cartilage cells. This work demonstrated clearly that the differentiative trait is more radiosensitive than is reproduction. Based on this finding a new compartment model is proposed for a cell renewal system which demonstrates the difference between normal and malignant tissue. (author)

  2. 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.

  3. Radiosensitivity of quince seeds (Cydonia oblonga Mill.)

    International Nuclear Information System (INIS)

    Dall'Orto, F.A.C.; Ojima, M.; Hiroce, R.; Igue, T.; Ferraz, E.S.B.; Nascimento Filho, V.F. do; Menten, J.O.M.; Tulmann Neto, A.; Ando, A.

    1984-01-01

    The investigation with quince seeds (Cydonia oblonga Mill.) radiosensitivity and the mineral composition of the plants obtained for mutation breeding are related. The concentration of some macro and micronutrients in quince seedlings obtained from irradiated seeds are studied. (M.A.C.) [pt

  4. 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

  5. Osmotic homeostasis and NKLy lymphoma cells radiosensitivity

    International Nuclear Information System (INIS)

    Tishchenko, V.V.; Magda, I.N.

    1992-01-01

    In experiments with cells of ascites NKLy lymphoma differing in ploidy and position in the cell cycle, a study was made of the radiosensitivity, osmotic homeostasis peculiarities and thermoradiation changes in potassium content. It was shown that the resistance of osmotic homeostasis of NKLy cells to thermoradiation correlated with their radioresistance

  6. 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

  7. 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.

  8. DIFFERENTIAL DIAGNOSTICS MODEL RESEARCH BY MEANS OF THE POTENTIAL FUNCTIONS METHOD FOR NEUROLOGY DISEASES CLASSIFICATION

    Directory of Open Access Journals (Sweden)

    V. Z. Stetsyuk

    2016-10-01

    Full Text Available Informatization in medicine offers a lot of opportunities to enhance quality of medical support, accuracy of diagnosis and provides the use of accumulated experience. Modern program systems are utilized now as additional tools to get appropriate advice. This article offers the way to provide help for neurology department doctor of NCSH «OKHMATDYT» during diagnosis determining. It was decided to design the program system for this purpose based on differential diagnostic model. The key problems in differential diagnosis are symptoms similarity between each other in one disease group and the absence of key symptom. Therefore the differential diagnostic model is needed. It is constructed using the potential function method in characteristics space. This characteristics space is formed by 100-200 points - patients with their symptoms. The main feature of this method here is that the decision function is building during recognition step united with learning that became possible with the help of modern powerful computers.

  9. Radiosensitization of hypoxic tumor cells by simultaneous administration of hyperthermia and nitroimidazoles

    International Nuclear Information System (INIS)

    Hofer, K.G.; Hofer, M.G.; Ieracitano, J.; McLaughlin, W.H.

    1977-01-01

    The radiation response of oxygenated and hypoxic L1210 leukemia cells subjected to in vivo treatments with hyperthermia and/or chemical radiosensitizers was evaluated with the [ 125 I]iododeoxyuridine prelabeling assay. X irradiation of L1210 cells at body temperatures of 41 0 C or higher resulted in strongly enhanced tumor cell death. The magnitude of this thermal effect increased with increasing temperatures. Hypoxic L1210 cells were particularly sensitive to heat induced enhancement of radiation damage, i.e., the sensitizing effects were more pronounced and occurred at lower temperatures. Chemical radiosensitizers (metronidazole, Ro 7-0582) selectively sensitized hypoxic L1210 populations; fully oxygenated cells were not affected. Considerable radiosensitization was achieved at nontoxic dose levels of the two sensitizers. Experiments designed to determine the degree of radiosensititization as a function of drug dose showed that Ro 7-0582 was consistently more effective than metronidazole in sensitizing hypoxic tumor populations. At the highest drug dose used (3 mg/g body wt) the DMF was 2.2 for metronidazole and 2.8 for Ro 7-0582. Combined administration of hyperthermia and Ro 7-0582 (or metronidazole) produced synergistic potentiation of radiation damage in hypoxic L1210 populations (DMF of 4.2). Under optimal conditions, hypoxic L1210 cells subjected simultaneously to both modes of radiosensitization became more radiosensitive than untreated, fully oxygenated L1210 cells. Experiments on two other tumor lines (BP-8 murine sarcoma and Ehrlich ascites cells) indicate that such synergistic radiosensitization effects are not unique to L1210 cells

  10. Comparisons of radiosensitivity and damage repair potential between mutants from the Saccharomyces cerevisiae strain of yeast and laboratory-bred wild yeasts with particular attention being given to giant cell formation after X-radiation

    International Nuclear Information System (INIS)

    Heinen, A.

    1988-01-01

    Yeast cells were exposed to X-rays at dose levels up to 10 kGy to induce damage to the DNA and investigate its effects on cellular growth patterns. For this purpose, comparisons were carried out between one diploid strain and six haploid strains of the Saccharomyces uvarum and Saccharomyces cerevisiae species, which permitted the individual recovery and damage repair pathways to be described in more detail. The laboratory-bred wild strains ATCC 9080, 211 and 706 were judged to have unimpaired repair mechanisms as compared to the auxotrophs, which fact was evident from the higher radiosensitivity of the latter. A further parameter in this evaluation of growth behaviours was giant cell formation. The results here provided evidence in confirmation of deviations between wild strains and mutants. Even though the ceiling values for the formation of giant cells were similarly high in all strains, impairments of cell division and initial development were observed for the mutants already at considerably lower dose levels. (orig./MG) [de

  11. 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)

  12. 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

  13. Yolk sac mesenchymal progenitor cells from New World mice (Necromys lasiurus with multipotent differential potential.

    Directory of Open Access Journals (Sweden)

    Phelipe Oliveira Favaron

    Full Text Available Fetal membranes are abundant, ethically acceptable and readily accessible sources of stem cells. In particular, the yolk sac is a source of cell lineages that do not express MHCs and are mainly free from immunological incompatibles when transferred to a recipient. Although data are available especially for hematopoietic stem cells in mice and human, whereas other cell types and species are dramatically underrepresented. Here we studied the nature and differentiation potential of yolk sac derived mesenchymal stem cells from a New World mouse, Necromys lasiurus. Explants from mid-gestation were cultured in DMEM-High glucose medium with 10% defined fetal bovine serum. The cells were characterized by standard methods including immunophenotyping by fluorescence and flow cytometry, growth and differentiation potential and tumorigenicity assays. The first adherent cells were observed after 7 days of cell culture and included small, elongated fibroblast-like cells (92.13% and large, round epithelial-like cells with centrally located nuclei (6.5%. Only the fibroblast-like cells survived the first passages. They were positive to markers for mesenchymal stem cells (Stro-1, CD90, CD105, CD73 and pluripotency (Oct3/4, Nanog as well as precursors of hematopoietic stem cells (CD117. In differentiation assays, they were classified as a multipotent lineage, because they differentiated into osteogenic, adipogenic, and chondrogenic lineages and, finally, they did not develop tumors. In conclusion, mesenchymal progenitor cells with multipotent differentiation potential and sufficient growth and proliferation abilities were able to be obtained from Necromys yolk sacs, therefore, we inferred that these cells may be promising for a wide range of applications in regenerative medicine.

  14. Potential differentiation of islet-like cells from pregnant cow-derived placental stem cells.

    Science.gov (United States)

    Peng, Shao-Yu; Chou, Chien-Wen; Kuo, Yu-Hsuan; Shen, Perng-Chih; Shaw, S W Steven

    2017-06-01

    Type 1 diabetes is an autoimmune disease that destroys islet cells and results in insufficient insulin secretion by pancreatic β-cells. Islet transplantation from donors is an approach used for treating patients with diabetes; however, this therapy is difficult to implement because of the lack of donors. Nevertheless, several stem cells have the potential to differentiate from islet-like cells and enable insulin secretion for treating diabetes in animal models. For example, placenta is considered a waste material and can be harvested noninvasively during delivery without ethical or moral concerns. To date, the differentiation of islet-like cells from cow-derived placental stem cells (CPSCs) has yet to be demonstrated. The investigation of potential differentiation of islet-like cells from CPSCs was conducted by supplementation with nicotinamide, exendin-4, glucose, and poly-d-lysine and was detected through reverse transcription polymerase chain reaction, dithizone staining, and immunocytochemical methods. Our results indicated that CPSCs are established and express mesenchymal stem cell surface antigen markers, such as CD73, CD166, β-integrin, and Oct-4, but not hematopoietic stem cell surface antigen markers, such as CD45. After induction, the CPSCs successfully differentiated into islet-like cells. The CPSC-derived islet-like cells expressed islet cell development-related genes, such as insulin, glucagon, pax-4, Nkx6.1, pax-6, and Fox. Moreover, CPSC-derived islet-like cells can be stained with zinc ions, which are widely distributed in the islet cells and enable insulin secretion. Altogether, islet-like cells have the potential to be differentiated from CPSCs without gene manipulation, and can be used in diabetic animal models in the future for preclinical and drug testing trial investigations. Copyright © 2017. Published by Elsevier B.V.

  15. A matter of identity — Phenotype and differentiation potential of human somatic stem cells

    Directory of Open Access Journals (Sweden)

    S.E.P. New

    2015-07-01

    Full Text Available Human somatic stem cells with neural differentiation potential can be valuable for developing cell-based therapies, including treatment of birth-related defects, while avoiding issues associated with cell reprogramming. Precisely defining the “identity” and differentiation potential of somatic stem cells from different sources, has proven difficult, given differences in sets of specific markers, protocols used and lack of side-by-side characterization of these cells in different studies. Therefore, we set to compare expression of mesenchymal and neural markers in human umbilical cord-derived mesenchymal stem cells (UC-MSCs, pediatric adipose-derived stem cells (p-ADSCs in parallel with human neural stem cells (NSCs. We show that UC-MSCs at a basal level express mesenchymal and so-called “neural” markers, similar to that we previously reported for the p-ADSCs. All somatic stem cell populations studied, independently from tissue and patient of origin, displayed a remarkably similar expression of surface markers, with the main difference being the restricted expression of CD133 and CD34 to NSCs. Expression of certain surface and neural markers was affected by the expansion medium used. As predicted, UC-MSCs and p-ADSCs demonstrated tri-mesenchymal lineage differentiation potential, though p-ADSCs display superior chondrogenic differentiation capability. UC-MSCs and p-ADSCs responded also to neurogenic induction by up-regulating neuronal markers, but crucially they appeared morphologically immature when compared with differentiated NSCs. This highlights the need for further investigation into the use of these cells for neural therapies. Crucially, this study demonstrates the lack of simple means to distinguish between different cell types and the effect of culture conditions on their phenotype, and indicates that a more extensive set of markers should be used for somatic stem cell characterization, especially when developing therapeutic

  16. Repulsive wall potentials for He-(Ne,Ar,Kr,Xe) as inferred from differential cross sections

    International Nuclear Information System (INIS)

    Nitz, D.E.; Larson, J.; Swanson, K.; Wildgoose, C.

    1993-01-01

    We have obtained representations of the He-(Ne,Ar,Kr,Xe) ground state repulsive walls using model potentials optimized to fit published absolute differential cross section data for 500 and 1500 eV collisions. The HeNe potential, like the He 2 potentials can be fit using the semi-empirical HFD-B form constrained to cross zero at the proper internuclear separation. For the heavier atoms, this approach is unsuccessful and superior fits are obtained using only the purely repulsive V(r) - A EXP [-αr - βr 2 ] term of the HFD-B potential. Comparison of fitted potentials with previous results will be presented

  17. Field differential equations for a potential flow from a Hamilton type variational principle

    International Nuclear Information System (INIS)

    Fierros Palacios, A.

    1992-01-01

    The same theoretical frame that was used to solve the problem of the field equations for a viscous fluid is utilized in this work. The purpose is to obtain the differential field equations for a potential flow from the Lagrangian formalism as in classical field theory. An action functional is introduced as a space-time integral over a region of three-dimensional Euclidean space, of a Lagrangian density as a function of certain field variables. A Hamilton type extremum action principle is postulated with adequate boundary conditions, and a set of differential field equations is derived. A particular Lagrangian density of the T-V type leads to the wave equation for the velocity potential. (Author)

  18. Mesenchymal precursor cells maintain the differentiation and proliferation potentials of breast epithelial cells

    Science.gov (United States)

    2014-01-01

    Introduction Stromal-epithelial interactions play a fundamental role in tissue homeostasis, controlling cell proliferation and differentiation. Not surprisingly, aberrant stromal-epithelial interactions contribute to malignancies. Studies of the cellular and molecular mechanisms underlying these interactions require ex vivo experimental model systems that recapitulate the complexity of human tissue without compromising the differentiation and proliferation potentials of human primary cells. Methods We isolated and characterized human breast epithelial and mesenchymal precursors from reduction mammoplasty tissue and tagged them with lentiviral vectors. We assembled heterotypic co-cultures and compared mesenchymal and epithelial cells to cells in corresponding monocultures by analyzing growth, differentiation potentials, and gene expression profiles. Results We show that heterotypic culture of non-immortalized human primary breast epithelial and mesenchymal precursors maintains their proliferation and differentiation potentials and constrains their growth. We further describe the gene expression profiles of stromal and epithelial cells in co-cultures and monocultures and show increased expression of the tumor growth factor beta (TGFβ) family member inhibin beta A (INHBA) in mesenchymal cells grown as co-cultures compared with monocultures. Notably, overexpression of INHBA in mesenchymal cells increases colony formation potential of epithelial cells, suggesting that it contributes to the dynamic reciprocity between breast mesenchymal and epithelial cells. Conclusions The described heterotypic co-culture system will prove useful for further characterization of the molecular mechanisms mediating interactions between human normal or neoplastic breast epithelial cells and the stroma, and will provide a framework to test the relevance of the ever-increasing number of oncogenomic alterations identified in human breast cancer. PMID:24916766

  19. Recent advances and potential applications of modulated differential scanning calorimetry (mDSC) in drug development

    DEFF Research Database (Denmark)

    Knopp, Matthias Manne; Löbmann, Korbinian; Elder, David P.

    2016-01-01

    Differential scanning calorimetry (DSC) is frequently the thermal analysis technique of choice within preformulation and formulation sciences because of its ability to provide detailed information about both the physical and energetic properties of a substance and/or formulation. However, convent......-dried formulations. However, as discussed in the present review, a number of other potential applications could also be relevant for the pharmaceutical scientist....

  20. 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.)

  1. Radiosensitizing and cytotoxic properties of DNA targeted phenanthridine-linked nitroheterocycles of varying electron affinities

    International Nuclear Information System (INIS)

    Cowan, D.S.M.; Rauth, A.M.; Toronto Univ., ON; Matejovic, J.F.; McClelland, R.A.; Wardman, P.

    1994-01-01

    2-Nitroimidazoles targeted to DNA via intercalation have previously been shown to be as much as 10-100 times more efficient on a molar basis than the untargeted nitroimidazole, misonidazole, in vitro as hypoxic cell selective radiosensitizers and cytotoxins based on extracellular concentrations. In this work the effect of varying the nitroaromatic group has been examined through the preparation of a DNA-targeted 4-nitroimidazole (4-MeNLP-3), a 5-nitroimidazole (5-NLP-3) and a 5-nitrofuran (FEP-2) linked to phenanthridinium ions. With the previously synthesized 2-nitroimidazoles, this provides a series of DNA targeted compounds of varying electron affinity as well as structure at the nitroaromatic position. The present series of compounds was tested for partition coefficient, DNA binding ability, reduction potentials and in vitro radiosensitizing and cytotoxic abilities. The results obtained indicate that targeting such compounds to DNA diminishes the dependency of radiosensitizing and cytotoxic properties on reduction potential and may allow significant uncoupling of toxicity from radiosensitizing ability. (author)

  2. 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)

  3. Cellular uptake and radiosensitization of SR-2508 loaded PLGA nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Jin Cheng [Fourth Military Medical University, Department of Radiation Medicine (China); Bai Ling [Xi' an Gaoxin Hospital, Department of Clinical Laboratories (China); Wu Hong [Fourth Military Medical University, Department of Pharmacy (China); Teng Zenghui [Fourth Military Medical University, Department of Pharmacology (China); Guo Guozhen, E-mail: guozhengg@tom.co [Fourth Military Medical University, Department of Radiation Medicine (China); Chen Jingyuan, E-mail: jy_chen@fmmu.edu.c [Fourth Military Medical University, Department of Occupational and Environmental Health (China)

    2008-08-15

    SR-2508 (etanidazole), a hypoxic radiosensitizer, has potential applications in radiotherapy. The poly(d,l-lactide-co-glycolide)(PLGA) nanoparticles containing SR-2508 were prepared by w/o/w emulsification-solvent evaporation method. The physicochemical characteristics of the nanoparticles (i.e. encapsulation efficiency, particle size distribution, morphology, in vitro release) were studied. The cellular uptake of the nanoparticles for the two human tumor cell lines: human breast carcinoma cells (MCF-7) and human carcinoma cervices cells (HeLa), was evaluated by fluorescence microscopy and transmission electronic microscopy. Cell viability was measured by the ability of single cell to form colonies in vitro. The prepared nanoparticles were spherical in shape with size between 90 nm and 190 nm. The encapsulation efficiency was 20.06%. The drug release pattern exhibited an initial burst followed by a plateau for over 24 h. The cellular uptake of nanoparticles was observed. Co-culture of MCF-7 and HeLa cells with SR-2508 loaded nanoparticles showed that released SR-2508 retained its bioactivity and effectively sensitized two hypoxic tumor cell lines to radiation. The radiosensitization of SR-2508 loaded nanoparticles was more significant than that of free drug.

  4. Characteristics of fluorinated nitroazoles as hypoxic cell radiosensitizers

    International Nuclear Information System (INIS)

    Shibamoto, Y.; Nishimoto, S.; Shimokawa, K.

    1989-01-01

    Types of 2-nitroimidazoles and 3-nitro-1,2,4-triazoles bearing one or two fluorine atoms on their side chains were synthesized to evaluate their physicochemical properties, radiosensitizing effects, and toxicity. The reduction potential of the compounds containing one fluorine was similar to that of misonidazole (MISO), whereas that of the difluorinated compounds was slightly higher. Both mono- and difluorinated compounds had an in vitro sensitizing activity comparable to or slightly higher than that of MISO. The fluorinated 3-nitrotriazoles were almost as efficient as the 2-nitroimidazoles with the same substituent. In vivo, some of the compounds were up to twice more efficient than MISO, whereas others were as efficient as MISO. Toxicity in terms of LD50/7 in mice was quite variable depending on the side-chain structure; the amide derivatives were less toxic than MISO, whereas the alcohol and ether derivatives were more toxic. In view of the radiosensitizing effect and toxicity in vivo, at least one compound, KU-2285 (a 2-nitroimidazole with an N1-substituent of: CH2CF2CONHCH2CH2OH) has been found to be as useful a hypoxic cell sensitizer as SR-2508

  5. 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.

  6. Cellular uptake and radiosensitization of SR-2508 loaded PLGA nanoparticles

    International Nuclear Information System (INIS)

    Jin Cheng; Bai Ling; Wu Hong; Teng Zenghui; Guo Guozhen; Chen Jingyuan

    2008-01-01

    SR-2508 (etanidazole), a hypoxic radiosensitizer, has potential applications in radiotherapy. The poly(d,l-lactide-co-glycolide)(PLGA) nanoparticles containing SR-2508 were prepared by w/o/w emulsification-solvent evaporation method. The physicochemical characteristics of the nanoparticles (i.e. encapsulation efficiency, particle size distribution, morphology, in vitro release) were studied. The cellular uptake of the nanoparticles for the two human tumor cell lines: human breast carcinoma cells (MCF-7) and human carcinoma cervices cells (HeLa), was evaluated by fluorescence microscopy and transmission electronic microscopy. Cell viability was measured by the ability of single cell to form colonies in vitro. The prepared nanoparticles were spherical in shape with size between 90 nm and 190 nm. The encapsulation efficiency was 20.06%. The drug release pattern exhibited an initial burst followed by a plateau for over 24 h. The cellular uptake of nanoparticles was observed. Co-culture of MCF-7 and HeLa cells with SR-2508 loaded nanoparticles showed that released SR-2508 retained its bioactivity and effectively sensitized two hypoxic tumor cell lines to radiation. The radiosensitization of SR-2508 loaded nanoparticles was more significant than that of free drug.

  7. Hypoxia Epigenetically Confers Astrocytic Differentiation Potential on Human Pluripotent Cell-Derived Neural Precursor Cells

    Directory of Open Access Journals (Sweden)

    Tetsuro Yasui

    2017-06-01

    Full Text Available Human neural precursor cells (hNPCs derived from pluripotent stem cells display a high propensity for neuronal differentiation, but they require long-term culturing to differentiate efficiently into astrocytes. The mechanisms underlying this biased fate specification of hNPCs remain elusive. Here, we show that hypoxia confers astrocytic differentiation potential on hNPCs through epigenetic gene regulation, and that this was achieved by cooperation between hypoxia-inducible factor 1α and Notch signaling, accompanied by a reduction of DNA methylation level in the promoter region of a typical astrocyte-specific gene, Glial fibrillary acidic protein. Furthermore, we found that this hypoxic culture condition could be applied to rapid generation of astrocytes from Rett syndrome patient-derived hNPCs, and that these astrocytes impaired neuronal development. Thus, our findings shed further light on the molecular mechanisms regulating hNPC differentiation and provide attractive tools for the development of therapeutic strategies for treating astrocyte-mediated neurological disorders.

  8. Fibronectin promotes differentiation of neural crest progenitors endowed with smooth muscle cell potential

    International Nuclear Information System (INIS)

    Costa-Silva, Bruno; Coelho da Costa, Meline; Melo, Fernanda Rosene; Neves, Cynara Mendes; Alvarez-Silva, Marcio; Calloni, Giordano Wosgrau; Trentin, Andrea Goncalves

    2009-01-01

    The neural crest (NC) is a model system used to investigate multipotency during vertebrate development. Environmental factors control NC cell fate decisions. Despite the well-known influence of extracellular matrix molecules in NC cell migration, the issue of whether they also influence NC cell differentiation has not been addressed at the single cell level. By analyzing mass and clonal cultures of mouse cephalic and quail trunk NC cells, we show for the first time that fibronectin (FN) promotes differentiation into the smooth muscle cell phenotype without affecting differentiation into glia, neurons, and melanocytes. Time course analysis indicated that the FN-induced effect was not related to massive cell death or proliferation of smooth muscle cells. Finally, by comparing clonal cultures of quail trunk NC cells grown on FN and collagen type IV (CLIV), we found that FN strongly increased both NC cell survival and the proportion of unipotent and oligopotent NC progenitors endowed with smooth muscle potential. In contrast, melanocytic progenitors were prominent in clonogenic NC cells grown on CLIV. Taken together, these results show that FN promotes NC cell differentiation along the smooth muscle lineage, and therefore plays an important role in fate decisions of NC progenitor cells

  9. TET1 knockdown inhibits the odontogenic differentiation potential of human dental pulp cells.

    Science.gov (United States)

    Rao, Li-Jia; Yi, Bai-Cheng; Li, Qi-Meng; Xu, Qiong

    2016-06-30

    Human dental pulp cells (hDPCs) possess the capacity to differentiate into odontoblast-like cells and generate reparative dentin in response to exogenous stimuli or injury. Ten-eleven translocation 1 (TET1) is a novel DNA methyldioxygenase that plays an important role in the promotion of DNA demethylation and transcriptional regulation in several cell lines. However, the role of TET1 in the biological functions of hDPCs is unknown. To investigate the effect of TET1 on the proliferation and odontogenic differentiation potential of hDPCs, a recombinant shRNA lentiviral vector was used to knock down TET1 expression in hDPCs. Following TET1 knockdown, TET1 was significantly downregulated at both the mRNA and protein levels. Proliferation of the hDPCs was suppressed in the TET1 knockdown groups. Alkaline phosphatase activity, the formation of mineralized nodules, and the expression levels of DSPP and DMP1 were all reduced in the TET1-knockdown hDPCs undergoing odontogenic differentiation. Based on these results, we concluded that TET1 knockdown can prevent the proliferation and odontogenic differentiation of hDPCs, which suggests that TET1 may play an important role in dental pulp repair and regeneration.

  10. Voltage-gated sodium channel expression and action potential generation in differentiated NG108-15 cells.

    Science.gov (United States)

    Liu, Jinxu; Tu, Huiyin; Zhang, Dongze; Zheng, Hong; Li, Yu-Long

    2012-10-25

    The generation of action potential is required for stimulus-evoked neurotransmitter release in most neurons. Although various voltage-gated ion channels are involved in action potential production, the initiation of the action potential is mainly mediated by voltage-gated Na+ channels. In the present study, differentiation-induced changes of mRNA and protein expression of Na+ channels, Na+ currents, and cell membrane excitability were investigated in NG108-15 cells. Whole-cell patch-clamp results showed that differentiation (9 days) didn't change cell membrane excitability, compared to undifferentiated state. But differentiation (21 days) induced the action potential generation in 45.5% of NG108-15 cells (25/55 cells). In 9-day-differentiated cells, Na+ currents were mildly increased, which was also found in 21-day differentiated cells without action potential. In 21-day differentiated cells with action potential, Na+ currents were significantly enhanced. Western blot data showed that the expression of Na+ channels was increased with differentiated-time dependent manner. Single-cell real-time PCR data demonstrated that the expression of Na+ channel mRNA was increased by 21 days of differentiation in NG108-15 cells. More importantly, the mRNA level of Na+ channels in cells with action potential was higher than that in cells without action potential. Differentiation induces expression of voltage-gated Na+ channels and action potential generation in NG108-15 cells. A high level of the Na+ channel density is required for differentiation-triggered action potential generation.

  11. Passage-restricted differentiation potential of mesenchymal stem cells into cardiomyocyte-like cells

    International Nuclear Information System (INIS)

    Zhang Fabao; Li Li; Fang Bo; Zhu Dingliang; Yang Huangtian; Gao Pingjin

    2005-01-01

    Mesenchymal stem cells (MSCs) have limited ability to differentiate into cardiomyocytes and the factors affect this process are not fully understood. In this study, we investigated the passage (P)-related transdifferentiation potential of MSCs into cardiomyocyte-like cells and its relationship to the proliferation ability. After 5-azacytidine treatment, only P4 but not P1 and P8 rat bone marrow MSCs (rMSCs) showed formation of myotube and expressed cardiomyocyte-associated markers. The growth property analysis showed P4 rMSCs had a growth-arrest appearance, while P1 and P8 rMSCs displayed an exponential growth pattern. When the rapid proliferation of P1 and P8 rMSCs was inhibited by 5-bromo-2-deoxyuridine, a mitosis inhibitor, only P1, not P8 rMSCs, differentiated into cardiomyocyte-like cells after 5-azacytidine treatment. These results demonstrate that the differentiation ability of rMSCs into cardiomyocytes is in proliferation ability-dependent and passage-restricted patterns. These findings reveal a novel regulation on the transdifferentiation of MSCs and provide useful information for exploiting the clinical therapeutic potential of MSCs

  12. 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)

  13. Gamma radiosensitivity of a common bean cultivar

    International Nuclear Information System (INIS)

    Colaco, W.; Martinez, C.R.

    1995-01-01

    A preliminary experiment was conducted to evaluate the radiosensitivity of common bean (Phaseolous vulgaris L.), cultivar to gamma rays from a 60 Co source. Sets of seeds (60 seed/sample) irradiated with 50, 100, 150, 200, and 250 Gy, were compared to a control without irradiation (0 Gy), under greenhouse conditions. The radiosensitivity was evaluated through seedling height reduction, determined at 15 days after emergence (DAE), and also through seedling survival, root length, and dry matter production of leaves, shoots and roots. Seedling height was significantly reduced for the treatments with 150 and 250 Gy, in relation to the control. The dose causing reduction of 50% seedling height was between 150 and 200 Gy. Survival rates corresponding to these doses, were, respectively, 85% and 60%. Root length and dry matter of leaves, shoots and roots, were inversely related to the doses. (author). 15 refs, 3 figs, 1 tab

  14. Effect of laser radiation on rat radiosensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Laprun, I.B.

    1979-03-01

    Quite a few experimental data have been obtained to date indicating that radioresistance of the organism is enhanced under the influence of electromagnetic emissions in the radiofrequency and optical ranges. But no studies were made of the possible radioprotective properties of coherent laser radiation. At the same time, it was demonstrated that the low-energy emission of optical quantum generators (lasers) in the red band stimulates the protective forces of the organism and accelerates regenerative processes; i.e., it induces effects that are the opposite of that of ionizing radiation. Moreover, it was recently demonstrated that there is activation of catalase, a radiosensitive enzyme that plays an important role in the metabolism of peroxide compounds, under the influence of lasers. For this reason, the effect of pre-exposure to laser beams on radiosensitivity of rats was tested.

  15. 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)

  16. Radiosensitivity study of salmonella enteritidis in chickens

    International Nuclear Information System (INIS)

    Fernandez Gianotti, Tomas

    1997-01-01

    One of the applications of ionizing radiations in food is the inactivation of vegetative phatogenic bacteria (radicidation) such as Salmonella, Shigella, Campylobacter, Vibro and Listeria. These bacteria are associated with the diseases transmitted by food (ETA). Fresh and frozen farmyard fowls can be contaminated with pathogenic microorganisms, between them Salmonella. In Argentine, between years 1987-1990, Salmonella enteritidis was the main cause of salmonellosis. In food irradiation, with the aim of improving and assuring its hygienic quality, it is important to know the radiosensitivity of microorganisms to be inactivated. Inactivation of a determined microorganism shall depend, between others factors, of the species, strain, number and of the irradiation conditions (temperature, media, etc.). D 10 value is a very useful data in order to compare radiosensitivities between the microorganisms and the influence of different factors in their sensitivities. In this paper, it was determined the sensitivity to the gamma radiation of Salmonella enteritidis in fresh and frozen chickens

  17. 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)

  18. DNA repair , cell repair and radiosensitivity

    International Nuclear Information System (INIS)

    Zhestyanikov, V.D.

    1983-01-01

    Data obtained in laboratory of radiation cytology and literature data testifying to a considerable role of DNA repair in cell sensitivity to radiation and chemical DNA-tropic agents have been considered. Data pointing to the probability of contribution of inducible repair of DNA into plant cells sensitivity to X-rays are obtained. Certain violations of DNA repair do not result in the increase of radiosensitivity. It is assumed that in the cases unknown mechanisms of DNA repair operate

  19. Radiosensitivity of red flour beetle tribolium castaneum

    International Nuclear Information System (INIS)

    Sattar, A.; Khattak, S.; Hamed, M.

    1992-07-01

    In this report radiosensitivity of red beetle has been discussed. Red flour beetle is the most injurious pest causing great losses to stored grain. Radiation is one of the best tools of insect control. Different radiation doses (50 to 200 krads) were employed for different age groups from 1 to 60 days. It is concluded from these results that 200 krad radiation dose caused 100% mortality in red beetle in all age group. (A.B.)

  20. Differentiation potential of STRO-1+ dental pulp stem cells changes during cell passaging

    Directory of Open Access Journals (Sweden)

    Wang Ruoning

    2010-05-01

    Full Text Available Abstract Background Dental pulp stem cells (DPSCs can be driven into odontoblast, osteoblast, and chondrocyte lineages in different inductive media. However, the differentiation potential of naive DPSCs after serial passaging in the routine culture system has not been fully elucidated. Results DPSCs were isolated from human/rat dental pulps by the magnetic activated cell sorting based on STRO-1 expression, cultured and passaged in the conventional culture media. The biological features of STRO-1+ DPSCs at the 1st and 9th passages were investigated. During the long-term passage, the proliferation ability of human STRO-1+ DPSCs was downregulated as indicated by the growth kinetics. When compared with STRO-1+ DPSCs at the 1st passage (DPSC-P1, the expression of mature osteoblast-specific genes/proteins (alkaline phosphatase, bone sialoprotein, osterix, and osteopontin, odontoblast-specific gene/protein (dentin sialophosphoprotein and dentin sialoprotein, and chondrocyte-specific gene/protein (type II collagen was significantly upregulated in human STRO-1+ DPSCs at the 9th passage (DPSC-P9. Furthermore, human DPSC-P9 cells in the mineralization-inducing media presented higher levels of alkaline phosphatase at day 3 and day 7 respectively, and produced more mineralized matrix than DPSC-P9 cells at day 14. In vivo transplantation results showed that rat DPSC-P1 cell pellets developed into dentin, bone and cartilage structures respectively, while DPSC-P9 cells can only generate bone tissues. Conclusions These findings suggest that STRO-1+ DPSCs consist of several interrelated subpopulations which can spontaneously differentiate into odontoblasts, osteoblasts, and chondrocytes. The differentiation capacity of these DPSCs changes during cell passaging, and DPSCs at the 9th passage restrict their differentiation potential to the osteoblast lineage in vivo.

  1. Evaluation of the effect of three monazite constituents on the radiosensitivity of human osteoblasts

    International Nuclear Information System (INIS)

    Iwahara, Lucas Kiyoshi da Fonseca; Oliveira, Monica Stuck de; Alencar, Marcus Alexandre Vallim de

    2017-01-01

    Thorium has gained notoriety in recent years, as a potential source of nuclear energy, substituting uranium in power plants. Monazite is an important font of thorium, as well of uranium and rare earths elements. Professionals involved in the extraction and manipulation of this mineral are occupationally exposed to aerosols containing metals and to ionizing radiation. This paper analyzed the effects of thorium, cerium and lanthanum on cell radiosensitivity. As an osteotropic substance, thorium is mostly deposited in bone tissue and may interfere in cellular radiosensitivity. A human osteoblast cell line was used to evaluate the effects of thorium, cerium and lanthanum on cell radiosensitivity, using proliferation as indicator. Assays were performed using cell cultures exposed to metals and to ionizing radiation. As a result, metals in combination with ionizing radiation induced changes on cell proliferation, in a concentration-dependent manner, in comparison with the exposure to metals alone. That suggests the possibility of combination interfering with radiosensitivity of osteoblasts, indicating an enhancement in occupational risk for workers that manipulate monazite byproducts and are subject to radiation in the environment. Thus, the development of risk assessment models that include the evaluation of metal-radiation mixtures and their cytotoxic and radiotoxic effects on tissues and organs must be highlighted. (author)

  2. 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.

  3. Studies on varietal radiosensitivity and genetical effect in triticum aestivum L

    International Nuclear Information System (INIS)

    Feng Zhijie; Wang Linqing

    1987-09-01

    The Dormand seeds (with 13% water content) of 49 wheat varieties (T riticum aestivum L.) were irradiated with 60 Co-γ ray of various doses, and the varietal radiosensitivities and the genetical effects were studied in experimental plots and laboratories. Significant differences in radiosensitivity were found among the varieties used in present experiment. The varietal radiosensitivity of T riticum aestivum L. manifested a continuous variation, which accords approximately with the normal distribution, from the sensitive to the resistant to 60 Co-γ rays. 49 varieties utilized could be divided into five groups with different radiosensitivity to 60 Co-γ rays: higher resistent, resistant, intermediat respose, sensitive and higher sensitive. It was found that most of the mutant varieties improved by irradiation were more resistant to γ rays than the local varieties which were more resistant than recombination varieties bred by crossbreeding, that is radiation-induced mutant varieties 2 generation. The results showed that mutation frequencies, mutation spectra and variebilities of the quantative traits varied with varieties. Higher mutation frequencies, wider mutation spectra and greater variabilities were observed in the sensitive varieties than in the resistant ones, and it suggested that there is a greater potential for selecting mutants in M 2 generation of more sensitive varieties

  4. 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.

  5. 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

  6. 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.

  7. 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

  8. 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

  9. Relation between number of hemopoietic stem cells in newborn mice and their radiosensitivity

    International Nuclear Information System (INIS)

    Sutter, T.; Maes, J.; Gerber, G.B.; Leonard, A.

    1985-01-01

    Fractionation of a radiation exposure causes greater damage in newborn mice than a single application since it induces radioresistant foetal hemopoietic stem cells to differentiate prematurely to more radiosensitive adult ones. In the present investigation, it was studied whether other agents that give rise to extensive stem cell destruction also lead to such a change in radiosensitivity. Indeed, treatment with cytostatic drugs which reduces the number of spleen colony forming units (CFU-s) and total cells also diminished the D 0 value of the surviving cells 3 days later. Adriamycin was most effective in causing damage to hemopoietic stem cells and in inducing micronuclei in bone marrow; it also had the most marked action on the D 0 of the surviving stem cells. (orig.)

  10. Wnt activation affects proliferation, invasiveness and radiosensitivity in medulloblastoma.

    Science.gov (United States)

    Salaroli, Roberta; Ronchi, Alice; Buttarelli, Francesca Romana; Cortesi, Filippo; Marchese, Valeria; Della Bella, Elena; Renna, Cristiano; Baldi, Caterina; Giangaspero, Felice; Cenacchi, Giovanna

    2015-01-01

    Medulloblastomas (MBs) associated with the Wnt activation represent a subgroup with a favorable prognosis, but it remains unclear whether Wnt activation confers a less aggressive phenotype and/or enhances radiosensitivity. To investigate this issue, we evaluated the biological behavior of an MB cell line, UW228-1, stably transfected with human β-catenin cDNA encoding a nondegradable form of β-catenin (UW-B) in standard culture conditions and after radiation treatment. We evaluated the expression, transcriptional activity, and localization of β-catenin in the stably transfected cells using immunofluorescence and WB. We performed morphological analysis using light and electron microscopy. We then analyzed changes in the invasiveness, growth, and mortality in standard culture conditions and after radiation. We demonstrated that (A) Wnt activation inhibited 97 % of the invasion capability of the cells, (B) the growth of the UW-B cells was statistically significantly lower than that of all the other control cells (p < 0.01), (C) the mortality of irradiated UW-B cells was statistically significantly higher than that of the controls and their nonirradiated counterparts (p < 0.05), and (D) morphological features of neuronal differentiation were observed in the Wnt-activated cells. In tissue samples, the Ki-67 labeling index (LI) was lower in β-catenin-positive samples compared to non-β-catenin positive ones. The Ki-67 LI median (LI = 40) of the nuclear β-catenin-positive tumor samples was lower than that of non-nuclear β-catenin-positive samples (LI = 50), but the difference was not statistically significant. Overall, our data suggest that activation of the Wnt pathway reduces the proliferation and invasion of MBs and increases the tumor's radiosensitivity.

  11. Donor cell type can influence the epigenome and differentiation potential of human induced pluripotent stem cells

    Science.gov (United States)

    Kim, Kitai; Zhao, Rui; Doi, Akiko; Ng, Kitwa; Unternaehrer, Juli; Cahan, Patrick; Hongguang, Huo; Loh, Yuin-Han; Aryee, Martin J.; Lensch, M. William; Li, Hu; Collins, James J.; Feinberg, Andrew P.; Daley, George Q.

    2012-01-01

    We compared bona-fide human induced pluripotent stem cells (iPSC) derived from umbilical cord blood (CB) and neonatal keratinocytes (K). As a consequence of both incomplete erasure of tissue-specific methylation and aberrant de novo methylation, CB-iPSC and K-iPSC are distinct in genome-wide DNA methylation profiles and differentiation potential. Extended passage of some iPSC clones in culture didn't improve their epigenetic resemblance to ESC, implying that some human iPSC retain a residual “epigenetic memory” of their tissue of origin. PMID:22119740

  12. 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

  13. Radiosensitization dependent on p53 function in bronchial carcinoma cells by the isoflavone genistein and estradiol in vitro

    International Nuclear Information System (INIS)

    Hermann, R.M.; Fest, J.; Christiansen, H.; Hille, A.; Rave-Fraenk, M.; Nitsche, M.; Gruendker, C.; Viereck, V.; Jarry, H.; Schmidberger, H.

    2007-01-01

    Background and Purpose: Simultaneous radiotherapy with chemotherapy is a standard treatment for inoperable non-small cell lung cancer (NSCLC), but the clinical outcome still remains poor. To further intensify treatment, substances need to be identified, which increase the effect of radiation on tumor cells without further enhancing toxicity to normal tissue. Hormones have a different toxicity profile than radiation or cytostatic drugs. As NSCLC often express estrogen receptors (ERs), the combination of genistein or estradiol and radiation in vitro was investigated. Material and Methods: A549 NSCLC cells with an inducible expression of a mutated TP53 and fibroblasts of a male donor (DF-18) were examined. ER expression was immunocytologically confirmed in all studied cell lines. Clonogenic survival was measured after incubation of the cells with genistein or estradiol (0.01 μM and 10 μM as maximum clinically applicable dose) and irradiation with different doses (0-4 Gy). The differentiation state of fibroblasts after combined therapy was analyzed. Results: A549 cells expressing mutated TP53 were more radioresistant than TP53 wild-type cells. Incubation of nonfunctional TP53 cells with genistein or estradiol increased radiosensitivity in both tested concentrations. By contrast, radiosensitivity of A549 with wild-type TP53 and DF-18 was not altered by hormonal incubation. In DF-18 radiation induced growth arrest that was not increased by additional hormonal incubation. Conclusion: NSCLC cells with nonfunctional TP53 might be sensitized against radiation by genistein or estradiol. As genistein is better tolerable than estradiol in patients, additional studies are warranted to assess potential gains of this combination therapy

  14. Raman spectroscopic analysis of gunshot residue offering great potential for caliber differentiation.

    Science.gov (United States)

    Bueno, Justin; Sikirzhytski, Vitali; Lednev, Igor K

    2012-05-15

    Near-infrared (NIR) Raman microspectroscopy combined with advanced statistics was used to differentiate gunshot residue (GSR) particles originating from different caliber ammunition. The firearm discharge process is analogous to a complex chemical reaction. The reagents of this process are represented by the chemical composition of the ammunition, firearm, and cartridge case. The specific firearm parameters determine the conditions of the reaction and thus the subsequent product, GSR. We found that Raman spectra collected from these products are characteristic for different caliber ammunition. GSR particles from 9 mm and 0.38 caliber ammunition, collected under identical discharge conditions, were used to demonstrate the capability of confocal Raman microspectroscopy for the discrimination and identification of GSR particles. The caliber differentiation algorithm is based on support vector machines (SVM) and partial least squares (PLS) discriminant analyses, validated by a leave-one-out cross-validation method. This study demonstrates for the first time that NIR Raman microspectroscopy has the potential for the reagentless differentiation of GSR based upon forensically relevant parameters, such as caliber size. When fully developed, this method should have a significant impact on the efficiency of crime scene investigations.

  15. Aqueous ethanolic extract of Tinospora cordifolia as a potential candidate for differentiation based therapy of glioblastomas.

    Directory of Open Access Journals (Sweden)

    Rachana Mishra

    Full Text Available Glioblastomas are the most aggressive primary brain tumors and their heterogeneity and complexity often renders them non responsive to various conventional treatments. Search for herbal products having potential anti-cancer activity is an active area of research in the Indian traditional system of medicine i.e., Ayurveda. Tinospora cordifolia, also named as 'heavenly elixir' is used in various ayurvedic decoctions as panacea to treat several body ailments. The current study investigated the anti-brain cancer potential of 50% ethanolic extract of Tinospora cordifolia (TCE using C6 glioma cells. TCE significantly reduced cell proliferation in dose-dependent manner and induced differentiation in C6 glioma cells, resulting in astrocyte-like morphology as indicated by phase contrast images, GFAP expression and process outgrowth data of TCE treated cells which exhibited higher number and longer processes than untreated cells. Reduced proliferation of cells was accompanied by enhanced expression of senescence marker, mortalin and its translocation from perinuclear to pancytoplasmic spaces. Further, TCE showed anti-migratory and anti-invasive potential as depicted by wound scratch assay and reduced expression of plasticity markers NCAM and PSA-NCAM along with MMP-2 and 9. On analysis of the cell cycle and apoptotic markers, TCE treatment was seen to arrest the C6 cells in G0/G1 and G2/M phase, suppressing expression of G1/S phase specific protein cyclin D1 and anti-apoptotic protein Bcl-xL, thus supporting its anti-proliferative and apoptosis inducing potential. Present study provides the first evidence for the presence of anti-proliferative, differentiation-inducing and anti-migratory/anti-metastatic potential of TCE in glioma cells and possible signaling pathways involved in its mode of action. Our primary data suggests that TCE and its active components may prove to be promising phytotherapeutic interventions in gliobalstoma multiformae. 

  16. 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)

  17. Articular cartilage-derived cells hold a strong osteogenic differentiation potential in comparison to mesenchymal stem cells in vitro

    International Nuclear Information System (INIS)

    Salamon, Achim; Jonitz-Heincke, Anika; Adam, Stefanie; Rychly, Joachim; Müller-Hilke, Brigitte; Bader, Rainer; Lochner, Katrin; Peters, Kirsten

    2013-01-01

    Cartilaginous matrix-degenerative diseases like osteoarthritis (OA) are characterized by gradual cartilage erosion, and also by increased presence of cells with mesenchymal stem cell (MSC) character within the affected tissues. Moreover, primary chondrocytes long since are known to de-differentiate in vitro and to be chondrogenically re-differentiable. Since both findings appear to conflict with each other, we quantitatively assessed the mesenchymal differentiation potential of OA patient cartilage-derived cells (CDC) towards the osteogenic and adipogenic lineage in vitro and compared it to that of MSC isolated from adipose tissue (adMSC) of healthy donors. We analyzed expression of MSC markers CD29, CD44, CD105, and CD166, and, following osteogenic and adipogenic induction in vitro, quantified their expression of osteogenic and adipogenic differentiation markers. Furthermore, CDC phenotype and proliferation were monitored. We found that CDC exhibit an MSC CD marker expression pattern similar to adMSC and a similar increase in proliferation rate during osteogenic differentiation. In contrast, the marked reduction of proliferation observed during adipogenic differentiation of adMSC was absent in CDC. Quantification of differentiation markers revealed a strong osteogenic differentiation potential for CDC, however almost no capacity for adipogenic differentiation. Since in the pathogenesis of OA, cartilage degeneration coincides with high bone turnover rates, the high osteogenic differentiation potential of OA patient-derived CDC may affect clinical therapeutic regimens aiming at autologous cartilage regeneration in these patients. - Highlights: • We analyze the mesenchymal differentiation capacity of cartilage-derived cells (CDC). • CDC express mesenchymal stem cell (MSC) markers CD29, CD44, CD105, and CD166. • CDC and MSC proliferation is reduced in adipogenesis and increased in osteogenesis. • Adipogenic differentiation is virtually absent in CDC, but

  18. Articular cartilage-derived cells hold a strong osteogenic differentiation potential in comparison to mesenchymal stem cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Salamon, Achim, E-mail: achim.salamon@med.uni-rostock.de [Department of Cell Biology, Rostock University Medical Center, Schillingallee 69, D-18057 Rostock (Germany); Jonitz-Heincke, Anika, E-mail: anika.jonitz@med.uni-rostock.de [Biomechanics and Implant Technology Research Laboratory, Department of Orthopedics, Rostock University Medical Center, Doberaner Straße 142, D-18057 Rostock (Germany); Adam, Stefanie, E-mail: stefanie.adam@med.uni-rostock.de [Department of Cell Biology, Rostock University Medical Center, Schillingallee 69, D-18057 Rostock (Germany); Rychly, Joachim, E-mail: joachim.rychly@med.uni-rostock.de [Department of Cell Biology, Rostock University Medical Center, Schillingallee 69, D-18057 Rostock (Germany); Müller-Hilke, Brigitte, E-mail: brigitte.mueller-hilke@med.uni-rostock.de [Institute of Immunology, Rostock University Medical Center, Schillingallee 68, D-18057 Rostock (Germany); Bader, Rainer, E-mail: rainer.bader@med.uni-rostock.de [Biomechanics and Implant Technology Research Laboratory, Department of Orthopedics, Rostock University Medical Center, Doberaner Straße 142, D-18057 Rostock (Germany); Lochner, Katrin, E-mail: katrin.lochner@med.uni-rostock.de [Biomechanics and Implant Technology Research Laboratory, Department of Orthopedics, Rostock University Medical Center, Doberaner Straße 142, D-18057 Rostock (Germany); Peters, Kirsten, E-mail: kirsten.peters@med.uni-rostock.de [Department of Cell Biology, Rostock University Medical Center, Schillingallee 69, D-18057 Rostock (Germany)

    2013-11-01

    Cartilaginous matrix-degenerative diseases like osteoarthritis (OA) are characterized by gradual cartilage erosion, and also by increased presence of cells with mesenchymal stem cell (MSC) character within the affected tissues. Moreover, primary chondrocytes long since are known to de-differentiate in vitro and to be chondrogenically re-differentiable. Since both findings appear to conflict with each other, we quantitatively assessed the mesenchymal differentiation potential of OA patient cartilage-derived cells (CDC) towards the osteogenic and adipogenic lineage in vitro and compared it to that of MSC isolated from adipose tissue (adMSC) of healthy donors. We analyzed expression of MSC markers CD29, CD44, CD105, and CD166, and, following osteogenic and adipogenic induction in vitro, quantified their expression of osteogenic and adipogenic differentiation markers. Furthermore, CDC phenotype and proliferation were monitored. We found that CDC exhibit an MSC CD marker expression pattern similar to adMSC and a similar increase in proliferation rate during osteogenic differentiation. In contrast, the marked reduction of proliferation observed during adipogenic differentiation of adMSC was absent in CDC. Quantification of differentiation markers revealed a strong osteogenic differentiation potential for CDC, however almost no capacity for adipogenic differentiation. Since in the pathogenesis of OA, cartilage degeneration coincides with high bone turnover rates, the high osteogenic differentiation potential of OA patient-derived CDC may affect clinical therapeutic regimens aiming at autologous cartilage regeneration in these patients. - Highlights: • We analyze the mesenchymal differentiation capacity of cartilage-derived cells (CDC). • CDC express mesenchymal stem cell (MSC) markers CD29, CD44, CD105, and CD166. • CDC and MSC proliferation is reduced in adipogenesis and increased in osteogenesis. • Adipogenic differentiation is virtually absent in CDC, but

  19. Functional relationships between genes associated with differentiation potential of aged myogenic progenitors

    Directory of Open Access Journals (Sweden)

    Radhakrishnan Nagarajan

    2010-09-01

    Full Text Available Aging is accompanied by considerable heterogeneity with possible co-expression of differentiation pathways. The present study investigates the interplay between crucial myogenic, adipogenic and Wnt-related genes orchestrating aged myogenic progenitor differentiation (AMPD using clonal gene expression profiling in conjunction with Bayesian structure learning (BSL techniques. The expression of three myogenic regulatory factor genes (Myogenin, Myf-5, MyoD1, four genes involved in regulating adipogenic potential (C/EBPα, DDIT3, FoxC2, PPARγ, and two genes in the Wnt-signaling pathway (Lrp5, Wnt5a known to influence both differentiation programs were determined across thirty-four clones by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR. Three control genes were used for normalization of the clonal expression data (18S, GAPDH and B2M. Constraint-based BSL techniques, namely (a PC Algorithm, (b Grow-shrink algorithm (GS, and (c Incremental Association Markov Blanket (IAMB were used to model the functional relationships (FRs in the form of acyclic networks from the clonal expression profiles. A novel resampling approach that obviates the need for a user-defined confidence threshold is proposed to identify statistically significant FRs at small sample sizes. Interestingly, the resulting acyclic network consisted of FRs corresponding to myogenic, adipogenic, Wnt-related genes and their interaction. A significant number of these FRs were robust to normalization across the three house-keeping genes and the choice of the BSL technique. The results presented elucidate the delicate balance between differentiation pathways (i.e. myogenic as well as adipogenic and possible cross-talk between pathways in AMPD.

  20. 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

  1. 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

  2. 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.

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

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    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. 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.

  5. 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

  6. MicroRNA Levels as Prognostic Markers for the Differentiation Potential of Human Mesenchymal Stromal Cell Donors

    NARCIS (Netherlands)

    Georgi, Nicole; Taipaleenmaeki, H.; Raiss, C.C.; Groen, N.; Portalska, K.K.; van Blitterswijk, Clemens; de Boer, Jan; Post, Janine Nicole; van Wijnen, A.; Karperien, Hermanus Bernardus Johannes

    2015-01-01

    The ability of human mesenchymal stromal/stem cells (hMSCs) to differentiate into various mesenchymal cell lineages makes them a promising cell source for the use in tissue repair strategies. Because the differentiation potential of hMSCs differs between donors, it is necessary to establish

  7. Intrinsic radiosensitivity and PLD repair in osteosarcoma cell lines

    International Nuclear Information System (INIS)

    Sugimoto, M.; Toguchida, J.; Kotoura, Y.; Yamamuro, T.; Utsumi, H.

    1992-01-01

    The response to radiation of seven osteosarcoma cell lines was analysed by in vitro colony-forming assay and compared with that of eight human fibroblast strains. The values of D 0 , the surviving fraction after 2 Gy (S2Gy), and the mean inactivation dose (D-bar) of osteosarcoma cells in log-phase culture were significantly higher than those of fibroblast strains (p<0.01). PLD (potentially lethal damage) repair of osteosarcoma cells evaluated in the plateau phase of growth showed great variation for enhancement of survival, although all of the values were maximised within 12 h after irradiation. In the osteosarcoma, intrinsic radiosensitivity in vitro reflected the clinical response to radiation. However, the capacity for PLD repair might not be a good indicator for predicting the results of radiation therapy. (author)

  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. 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.

  11. 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.)

  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. Neural differentiation potential of human bone marrow-derived mesenchymal stromal cells: misleading marker gene expression

    Directory of Open Access Journals (Sweden)

    Montzka Katrin

    2009-03-01

    Full Text Available Abstract Background In contrast to pluripotent embryonic stem cells, adult stem cells have been considered to be multipotent, being somewhat more restricted in their differentiation capacity and only giving rise to cell types related to their tissue of origin. Several studies, however, have reported that bone marrow-derived mesenchymal stromal cells (MSCs are capable of transdifferentiating to neural cell types, effectively crossing normal lineage restriction boundaries. Such reports have been based on the detection of neural-related proteins by the differentiated MSCs. In order to assess the potential of human adult MSCs to undergo true differentiation to a neural lineage and to determine the degree of homogeneity between donor samples, we have used RT-PCR and immunocytochemistry to investigate the basal expression of a range of neural related mRNAs and proteins in populations of non-differentiated MSCs obtained from 4 donors. Results The expression analysis revealed that several of the commonly used marker genes from other studies like nestin, Enolase2 and microtubule associated protein 1b (MAP1b are already expressed by undifferentiated human MSCs. Furthermore, mRNA for some of the neural-related transcription factors, e.g. Engrailed-1 and Nurr1 were also strongly expressed. However, several other neural-related mRNAs (e.g. DRD2, enolase2, NFL and MBP could be identified, but not in all donor samples. Similarly, synaptic vesicle-related mRNA, STX1A could only be detected in 2 of the 4 undifferentiated donor hMSC samples. More significantly, each donor sample revealed a unique expression pattern, demonstrating a significant variation of marker expression. Conclusion The present study highlights the existence of an inter-donor variability of expression of neural-related markers in human MSC samples that has not previously been described. This donor-related heterogeneity might influence the reproducibility of transdifferentiation protocols as

  14. 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.

  15. 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)

  16. 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

  17. 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

  18. The differentiation potential of adipose tissue-derived mesenchymal stem cells into cell lineage related to male germ cells

    Directory of Open Access Journals (Sweden)

    P. Bräunig

    Full Text Available ABSTRACT The adipose tissue is a reliable source of Mesenchymal stem cells (MSCs showing a higher plasticity and transdifferentiation potential into multilineage cells. In the present study, adipose tissue-derived mesenchymal stem cells (AT-MSCs were isolated from mice omentum and epididymis fat depots. The AT-MSCs were initially compared based on stem cell surface markers and on the mesodermal trilineage differentiation potential. Additionally, AT-MSCs, from both sources, were cultured with differentiation media containing retinoic acid (RA and/or testicular cell-conditioned medium (TCC. The AT-MSCs expressed mesenchymal surface markers and differentiated into adipogenic, chondrogenic and osteogenic lineages. Only omentum-derived AT-MSCs expressed one important gene marker related to male germ cell lineages, after the differentiation treatment with RA. These findings reaffirm the importance of adipose tissue as a source of multipotent stromal-stem cells, as well as, MSCs source regarding differentiation purpose.

  19. Potential of bursa-immigrated hematopoietic precursor cells to differentiate to functional B and T cells

    International Nuclear Information System (INIS)

    Weber, W.T.; Alexander, J.E.

    1978-01-01

    The potential of hematopoietic precursor cells, recently immigrated into the 13- and 14-day-old embryonic bursa, to migrate to the thymus and to differentiate to functional T cells was investigated. Chromosomally marked cell populations obtained from 13- and 14-day-old embryonic bursas were transferred i.v. to 780 R γ-irradiated chick embryos of equivalent age. When appropriate chimeras were examined at 4 to 12 weeks after cell transfer, donor cells were found to proliferate primarily in the bursa. Significant donor cell influx into the thymus was not detected. In correlation with these findings, Con A- and PHA-responsive T cells in thymus and spleen cell cultures of recipients remained of host origin whereas the number of anti-CIg responsive B cells of donor type increased gradually in the spleens of recipients. An initial lag period preceded the accumulation of functional donor B cells in the spleens of recipients, despite the predominant presence of dividing donor cells in the bursa. This suggests that the transferred bursal cell population required substantially longer to mature and emigrate from the bursa as functional B cells than the host cell population remaining in the irradiated bursas at time of cell transfer. The failure to detect significant influx of donor cells into the thymus and their failure to differentiate to functional T cells suggest that the recently bursa-immigrated hematopoietic stem cells of 13- and 14-day-old embryos may not be pluripotential cells, but rather cells already committed to the B cell line of differentiation

  20. 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)

  1. Radiosensitization of thymidine in deaerated aqueous solution

    International Nuclear Information System (INIS)

    Berger, Maurice.

    1982-09-01

    This work investigates the mode of action of various radiosensitizing agents on the radio-induced degradation of thymidine in deaerated aqueous solution. A special effort was devoted to the separation of addition products formed by one of these substances (a stable nitroxide radical: TAN) with the radio-induced neutral radicals of thymidine. The complex mixture of different diastereoisomers resulting from the covalent addition of the TAN molecule on the thymidine carbons C (5) or C (6) was resolved by HPLC. The structural determination of these adducts (absolute configuration) was achieved by various spectroscopic techniques and specific chemical syntheses. A conformational study has been undertaken [fr

  2. Analysis of mice radiosensitivity depending on age

    International Nuclear Information System (INIS)

    Bogatyrev, A.V.; Timoshenko, S.I.; Nikanorova, N.G.; Sverdlov, A.G.

    1979-01-01

    In order to elucidate mechanisms of age variations in radiosensitivity of mice a study was made of the sensitivity of in vitro irradiated bone marrow stem cells, taken from animals of different age, and postradiation recovery of leukocyte content of peripheral blood and cellularity of bone marrow and spleen. Using the method of spleen colonies similar affections were revealed in bone marrow cells of animals of different age. The degree of recovery of the hemopoietic cell pool was significantly lower in newborn mice than in adults after exposure to a dose (LDsub(50/30)) equally effective with respect to mortality

  3. Radiosensitivity study in rice (Oriza Sativa Lin.)

    International Nuclear Information System (INIS)

    Gonzalez, M.; Santana, N.; Diaz, R.

    1987-01-01

    Four rice varieties (J-104, Amistad-82, 6066 and IR-1529) were irradiated at doses of 10,15,20,25,30,35,40,45,50 and 55 Krad of gamma rays so as to determine radiosensitivity curves for each of the varieties for the following factors; seed germination percentage; survival percentage; height of the plant; length of roots. It was determined that IR-1529 variety is the one with the highest sensitivity and that radiations over 35 Krad should not be used for none of the varieties above mentioned

  4. Different radiosensitivities of mast-cell precursors in the bone marrow and skin of mice

    International Nuclear Information System (INIS)

    Kitamura, Y.; Yokoyama, M.; Sonoda, T.; Mori, K.J.

    1983-01-01

    Although tissue mast cells are derived from the bone marrow, some descendants of bone marrow-derived precursors retain the ability to proliferate and differentiate into mast cells even after localization in the skin. The purpose of the present study was to determine the D 0 values for mast-cell precursors in the bone marrow and those localized in the skin. Bone marrow cells were removed from (WB X C57BL/6)F 1 +/+ mice after various doses of irradiation and injected into the skin of the congenic W/W/sup v/ mice which were genetically without mast cells. Radiosensitivity of mast-cell precursors in the bone marrow was evaluated by determining the proportion of the injection sites at which mast cells did not appear. For the assay of the radiosensitivity of mast-cell precursors localized in the skin, pieces of skin were removed from beige C57BL/6 (bg/sup J//bg/sup J/, Chediak-Higashi syndrome) mice after various doses of irradiation and grafted onto the backs of the normal C57BL/6 mice. Radiosensitivity of mast-cell precursors in the skin was evaluated by determining the decrease of beige-type mast cells which possessed giant granules. Mast-cell precursors in the bone marrow were much more radiosenitive than those localized in the skin. D 0 value was about 100 rad for the former and about 800 rad for the latter

  5. Carvacrol promotes angiogenic paracrine potential and endothelial differentiation of human mesenchymal stem cells at low concentrations.

    Science.gov (United States)

    Matluobi, Danial; Araghi, Atefeh; Maragheh, Behnaz Faramarzian Azimi; Rezabakhsh, Aysa; Soltani, Sina; Khaksar, Majid; Siavashi, Vahid; Feyzi, Adel; Bagheri, Hesam Saghaei; Rahbarghazi, Reza; Montazersaheb, Soheila

    2018-01-01

    Phenolic monoterpene compound, named Carvacrol, has been found to exert different biological outcomes. It has been accepted that the angiogenic activity of human mesenchymal stem cells was crucial in the pursuit of appropriate regeneration. In the current experiment, we investigated the contribution of Carvacrol on the angiogenic behavior of primary human mesenchymal stem cells. Mesenchymal stem cells were exposed to Carvacrol in a dose ranging from 25 to 200μM for 48h. We measured cell survival rate by MTT assay and migration rate by a scratch test. The oxidative status was monitored by measuring SOD, GPx activity. The endothelial differentiation was studied by evaluating the level of VE-cadherin and vWF by real-time PCR and ELISA analyses. The content of VEGF and tubulogenesis behavior was monitored in vitro. We also conducted Matrigel plug in vivo CAM assay to assess the angiogenic potential of conditioned media from human mesenchymal stem cells after exposure to Carvacrol. Carvacrol was able to increase mesenchymal stem cell survival and migration rate (pcells by detecting vWF and VE-cadherin expression (pmesenchymal stem cells conditioned media improved angiogenesis tube formation in vitro (pmesenchymal stem cells by modulating cell differentiation and paracrine angiogenic response. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Computational Challenge of Fractional Differential Equations and the Potential Solutions: A Survey

    Directory of Open Access Journals (Sweden)

    Chunye Gong

    2015-01-01

    Full Text Available We present a survey of fractional differential equations and in particular of the computational cost for their numerical solutions from the view of computer science. The computational complexities of time fractional, space fractional, and space-time fractional equations are O(N2M, O(NM2, and O(NM(M + N compared with O(MN for the classical partial differential equations with finite difference methods, where M, N are the number of space grid points and time steps. The potential solutions for this challenge include, but are not limited to, parallel computing, memory access optimization (fractional precomputing operator, short memory principle, fast Fourier transform (FFT based solutions, alternating direction implicit method, multigrid method, and preconditioner technology. The relationships of these solutions for both space fractional derivative and time fractional derivative are discussed. The authors pointed out that the technologies of parallel computing should be regarded as a basic method to overcome this challenge, and some attention should be paid to the fractional killer applications, high performance iteration methods, high order schemes, and Monte Carlo methods. Since the computation of fractional equations with high dimension and variable order is even heavier, the researchers from the area of mathematics and computer science have opportunity to invent cornerstones in the area of fractional calculus.

  7. In vitro proliferation and differentiation of hepatic oval cells and their potential capacity for intrahepatic transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Z.; Chen, J. [Liaocheng People' s Hospital, Department of Hepatobiliary Surgery, Liaocheng, Shandong, China, Department of Hepatobiliary Surgery, Liaocheng People’s Hospital, Liaocheng, Shandong (China); Li, L.; Ran, J.H.; Liu, J. [The First People' s Hospital of Kunming, Kunming, Yunnan, China, The First People’s Hospital of Kunming, Kunming, Yunnan (China); Gao, T.X.; Guo, B.Y. [Dongchangfu Hospital of Women and Child Health Care, Liaocheng, Shandong (China); Li, X.H.; Liu, Z.H.; Liu, G.J.; Gao, Y.C.; Zhang, X.L. [Liaocheng People' s Hospital, Department of Hepatobiliary Surgery, Liaocheng, Shandong, China, Department of Hepatobiliary Surgery, Liaocheng People’s Hospital, Liaocheng, Shandong (China)

    2013-07-30

    Hepatic oval cells (HOCs) are recognized as facultative liver progenitor cells that play a role in liver regeneration after acute liver injury. Here, we investigated the in vitro proliferation and differentiation characteristics of HOCs in order to explore their potential capacity for intrahepatic transplantation. Clusters or scattered HOCs were detected in the portal area and interlobular bile duct in the liver of rats subjected to the modified 2-acetylaminofluorene and partial hepatectomy method. Isolated HOCs were positive for c-kit and CD90 staining (99.8% and 88.8%, respectively), and negative for CD34 staining (3.6%) as shown by immunostaining and flow cytometric analysis. In addition, HOCs could be differentiated into hepatocytes and bile duct epithelial cells after leukemia inhibitory factor deprivation. A two-cuff technique was used for orthotopic liver transplantation, and HOCs were subsequently transplanted into recipients. Biochemical indicators of liver function were assessed 4 weeks after transplantation. HOC transplantation significantly prolonged the median survival time and improved the liver function of rats receiving HOCs compared to controls (P=0.003, Student t-test). Administration of HOCs to rats also receiving liver transplantation significantly reduced acute allograft rejection compared to control liver transplant rats 3 weeks following transplantation (rejection activity index score: control=6.3±0.9; HOC=3.5±1.5; P=0.005). These results indicate that HOCs may be useful in therapeutic liver regeneration after orthotopic liver transplantation.

  8. In vitro proliferation and differentiation of hepatic oval cells and their potential capacity for intrahepatic transplantation

    International Nuclear Information System (INIS)

    Li, Z.; Chen, J.; Li, L.; Ran, J.H.; Liu, J.; Gao, T.X.; Guo, B.Y.; Li, X.H.; Liu, Z.H.; Liu, G.J.; Gao, Y.C.; Zhang, X.L.

    2013-01-01

    Hepatic oval cells (HOCs) are recognized as facultative liver progenitor cells that play a role in liver regeneration after acute liver injury. Here, we investigated the in vitro proliferation and differentiation characteristics of HOCs in order to explore their potential capacity for intrahepatic transplantation. Clusters or scattered HOCs were detected in the portal area and interlobular bile duct in the liver of rats subjected to the modified 2-acetylaminofluorene and partial hepatectomy method. Isolated HOCs were positive for c-kit and CD90 staining (99.8% and 88.8%, respectively), and negative for CD34 staining (3.6%) as shown by immunostaining and flow cytometric analysis. In addition, HOCs could be differentiated into hepatocytes and bile duct epithelial cells after leukemia inhibitory factor deprivation. A two-cuff technique was used for orthotopic liver transplantation, and HOCs were subsequently transplanted into recipients. Biochemical indicators of liver function were assessed 4 weeks after transplantation. HOC transplantation significantly prolonged the median survival time and improved the liver function of rats receiving HOCs compared to controls (P=0.003, Student t-test). Administration of HOCs to rats also receiving liver transplantation significantly reduced acute allograft rejection compared to control liver transplant rats 3 weeks following transplantation (rejection activity index score: control=6.3±0.9; HOC=3.5±1.5; P=0.005). These results indicate that HOCs may be useful in therapeutic liver regeneration after orthotopic liver transplantation

  9. Differential proteomics of human seminal plasma: A potential target for searching male infertility marker proteins.

    Science.gov (United States)

    Tomar, Anil Kumar; Sooch, Balwinder Singh; Singh, Sarman; Yadav, Savita

    2012-04-01

    The clinical fertility tests, available in the market, fail to define the exact cause of male infertility in almost half of the cases and point toward a crucial need of developing better ways of infertility investigations. The protein biomarkers may help us toward better understanding of unknown cases of male infertility that, in turn, can guide us to find better therapeutic solutions. Many clinical attempts have been made to identify biomarkers of male infertility in sperm proteome but only few studies have targeted seminal plasma. Human seminal plasma is a rich source of proteins that are essentially required for development of sperm and successful fertilization. This viewpoint article highlights the importance of human seminal plasma proteome in reproductive physiology and suggests that differential proteomics integrated with functional analysis may help us in searching potential biomarkers of male infertility. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Differential neurotoxic effects of silver nanoparticles: A review with special emphasis on potential biomarkers

    Directory of Open Access Journals (Sweden)

    M. Safari

    2016-04-01

    Full Text Available Silver Nanoparticles (AgNPs have gained considerable interests during the last decade due to their excellent antimicrobial activities. Despite their extensive use, the potential toxicity of these nanoparticles and possible mechanisms by which they may induce adverse reactions have not received sufficient attention and no specific biomarker exist to describe and quantify their toxic effects. Nanoparticles, depending on their physicochemical characteristics and compositions, can interact with vital organs such as the brain and induce toxic effects. A specific concern is that any contact with AgNPs independent of the route of administration is thought to result in significant systemic uptake, internal exposure of sensitive organs, especially in the central nervous system (CNS and different toxic responses. There are considerable evidences that AgNPs can disrupt the Blood-Brain Barrier (BBB and induce subsequent brain edema formation. Therefore, it is essential to understand the differential effects of AgNPs on brain cell with especial emphasis on the possible mechanisms of action. Recently, biomarkers are increasingly used as surrogate indicators of toxic responses in biological monitoring due to the inaccessibility of target organs. Moreover, as the most nanoscale contaminants occur at low concentrations, physiological biomarkers may be better indicators of potential impact of nanomaterials than traditional toxicity testing. This review aims to investigate the effects of AgNPs on CNS targets of toxicity and clarify the role of existing biomarkers especially the role of dopamine levels as a potential biomarker of Ag-NPs neurotoxicity.

  11. Radiosensitivity of human haematopoietic stem/progenitor cells

    International Nuclear Information System (INIS)

    Kato, Kengo; Kashiwakura, Ikuo; Omori, Atsuko

    2013-01-01

    The haematopoietic system is regenerative tissue with a high proliferative potential; therefore, haematopoietic stem cells (HSCs) are sensitive to extracellular oxidative stress caused by radiation and chemotherapeutic agents. An understanding of this issue can help predict haematopoietic recovery from radiation exposure as well as the extent of radiation damage to the haematopoietic system. In the present study, the radiosensitivity of human lineage-committed myeloid haematopoietic stem/progenitor cells (HSPCs), including colony-forming unit–granulocyte macrophage, burst-forming unit–erythroid and colony-forming unit–granulocyte–erythroid–macrophage–megakaryocyte cells, which are contained in adult individual peripheral blood (PB) and fetus/neonate placental/umbilical cord blood (CB), were studied. The PB of 59 healthy individual blood donors and the CB of 42 neonates were investigated in the present study. HSPCs prepared from PB and CB were exposed to 0.5 or 2 Gy x-irradiation. The results showed that large individual differences exist in the surviving fraction of cells. In the case of adult PB, a statistically significant negative correlation was observed between the surviving fraction observed at a dose of 0.5 Gy and the age of the blood donors; however, none of these correlations were observed after 2 Gy x-irradiation. In addition, seasonal and gender variation were observed in the surviving fraction of CB HSPCs. The present results suggest that there are large individual differences in the surviving fraction of HSPCs contained in both adult PB and fetus/neonate CB. In addition, some factors, including the gender, age and season of birth, affect the radiosensitivity of HSPCs, especially with a relatively low-dose exposure. (paper)

  12. 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.

  13. The toxic effects, GSH depletion and radiosensitivity by BSO on retinoblastoma

    International Nuclear Information System (INIS)

    Xianjin Yi; Li Ding; Yizun Jin; Chuo Ni; Wenji Wang

    1994-01-01

    Retinoblastoma is the most common intraocular malignant tumor in children. Previous investigations have reported that buthionine sulfoximine (BSO) can deplete intracellular glutathione (GSH) by specific inhibition and increase cellular radiosensitivity. The toxic effects, GSH depletion and radiosensitivity effects of BSO on retinoblastoma cells are reported in this paper. GSH content of retinoblastoma cell lines Y-79, So-Rb50 and retinoblastoma xenograft is 2.7 ± 1.3 X 1.0 -12 mmol/cell, 1.4 ± 0.2 X 1.0 -12 mmol/cell, and 2.8 ± 1.2 μmol/g, respectively. The ID 50 of BSO on Y-79 and So-Rb50 in air for 3 h exposure is 2.5 mM and 0.2 mM, respectively. GSH depletion by 0.1 mM BSO for 24 h on Y-79 cells and 0.01 mM BSO for 24 h on So-Rb50 cells is 16.35%, and 4.7% of control. GSH depletion in tumor and other organ tissues in retinoblastoma-bearing nude mice after BSO administration is differential. GSH depletion after BSO exposure in Y-79 cells in vitro decreases the Do value of retinoblastoma cells. The SER of 0.01 mM and 0.05 mM BSO for 24 h under hypoxic conditions is 1.21 and 1.36, respectively. Based on these observations, the authors conclude that BSO toxicity on retinoblastoma cells depends on the characteristics of the cell line and that BSO can increase hypoxic retinoblastoma cells' radiosensitivity in vitro. Further study of BSO radiosensitization on retinoblastoma in vivo using nude mouse xenografts is needed. 25 refs., 3 figs., 3 tabs

  14. The toxic effects, GSH depletion and radiosensitivity by BSO on retinoblastoma

    International Nuclear Information System (INIS)

    Yi Xianjin; Ni Chuo; Wang Wengi; Li Ding; Jin Yizun

    1993-01-01

    Retinoblastoma is the most common intraocular malignant tumor in children. Previous investigations have reported that buthionine sulfoximine (BSO) can deplete intracellular glutathione (GSH) by the specific inhibition and increase cellular radiosensitivity. The toxic effects, GSH depletion and radiosensitivity of BSO on retinoblastoma were reported. GSH content of retinoblastoma cell lines Y-79, So-Rb50 and retinoblastoma xenograft is (2.7 +- 1.3) x 10 -12 mmol/cell, (1.4 +- 0.2) x 10 -12 mmol/cell, and 2.8 +- 1.2 μmol/g respectively. The ID50 of BSO on Y-79 and So-Rb50 in air for 3h exposure is 2.5 mM and 0.2 mM respectively. GSH depletion by 0.1 mM BSO for 24h on Y-79 cells and 0.01 mM BSO for 24 h on So-Rb50 cells is 16.35%, and 4.7% of control. GSH depletion in tumor and other organ tissues in retinoblastoma bearing nude mice after BSO administration is differential. BSH depletion after BSO exposure in Y-79 cells in vitro decrease the D 0 value of retinoblastoma cells. The SER of 0.01 mM and 0.05 mM BSO for 24 h under the hypoxic condition is 1.21 and 1.36 respectively. Based on these observations, the authors conclude that BSO toxicity on retinoblastoma cells depends on the characteristics of cell line and BSO can increase hypoxic retinoblastoma cells radiosensitivity in vitro. Further study of BSO radiosensitization on retinoblastoma in vivo using nude mouse xenograft is needed

  15. The effects of ion adsorption on the potential of zero charge and the differential capacitance of charged aqueous interfaces

    Science.gov (United States)

    Uematsu, Yuki; Netz, Roland R.; Bonthuis, Douwe Jan

    2018-02-01

    Using a box profile approximation for the non-electrostatic surface adsorption potentials of anions and cations, we calculate the differential capacitance of aqueous electrolyte interfaces from a numerical solution of the Poisson-Boltzmann equation, including steric interactions between the ions and an inhomogeneous dielectric profile. Preferential adsorption of the positive (negative) ion shifts the minimum of the differential capacitance to positive (negative) surface potential values. The trends are similar for the potential of zero charge; however, the potential of zero charge does not correspond to the minimum of the differential capacitance in the case of asymmetric ion adsorption, contrary to the assumption commonly used to determine the potential of zero charge. Our model can be used to obtain more accurate estimates of ion adsorption properties from differential capacitance or electrocapillary measurements. Asymmetric ion adsorption also affects the relative heights of the characteristic maxima in the differential capacitance curves as a function of the surface potential, but even for strong adsorption potentials the effect is small, making it difficult to reliably determine the adsorption properties from the peak heights.

  16. A direct indication of plasma potential diagnostic with fast time response and high accuracy based on a differential emissive probe

    International Nuclear Information System (INIS)

    Yao, W.E.; Hershkowitz; Intrator, T.

    1985-01-01

    The floating potential of the emissive probe has been used to directly measure the plasma potential. The authors have recently presented another method for directly indicating the plasma potential with a differential emissive probe. In this paper they describe the effects of probe size, plasma density and plasma potential fluctuation on plasma potential measurements and give methods for reducing errors. A control system with fast time response (α 20 μs) and high accuracy (the order of the probe temperature T/sub w//e) for maintaining a differential emissive probe at plasma potential has been developed. It can be operated in pulsed discharge plasma to measure plasma potential dynamic characteristics. A solid state optical coupler is employed to improve circuit performance. This system was tested experimentally by measuring the plasma potential in an argon plasma device an on the Phaedrus tandem mirror

  17. A direct indication of plasma potential diagnostic with fast time response and high accuracy based on a differential emissive probe

    International Nuclear Information System (INIS)

    Yao, W.E.; Hershkowitz, N.; Intrator, T.

    1985-01-01

    The floating potential of the emissive probe has been used to directly measure the plasma potential. The authors have recently presented another method for directly indicating the plasma potential with a differential emissive probe. In this paper they describe the effects of probe size, plasma density and plasma potential fluctuation on plasma potential measurements and give methods for reducing errors. A control system with fast time response (≅ 20 μs) and high accuracy (the order of the probe temperature T/sub w//e) for maintaining a differential emissive probe at plasma potential has been developed. It can be operated in pulsed discharge plasma to measure plasma potential dynamic characteristics. A solid state optical coupler is employed to improve circuit performance. This system was tested experimentally by measuring the plasma potential in an argon plasma device and on the Phaedrus tandem mirror

  18. Mechanisms of oxygen radiosensitization in CHO cells

    International Nuclear Information System (INIS)

    Whillans, D.W.

    1981-01-01

    A model is presented for repair and fixation pathways when CHO cells are irradiated in the presence of O 2 . This analysis predicts that an increase in the repair path such as has been postulated for addition of a radioprotective sulfhydryl should increase OER/sub max/ in porportion to k prime, the new repair rate constant and also increase K with k prime. Any radiosensitizer which mimics the action of O 2 simply increases k prime 2 , so that the OER/sub max/ decreases at 1/k prime 2 but K increases as k prime 2 . These predictions have been tested in mammalian CHO cells making use of a Clark-type oxygen probe with defined conditions to ensure that O 2 is not depleted by radiation or cellular consumption, and so O 2 levels are known with accuracy. In a complementary study, the technique of rapid-mixing was used to measure the rate of development of O 2 sensitization in these same cells. By a variation of this rapid-mixing approach, the rate of diffusion into these cells has also been measured independently. Neither the dependence of OER on O 2 concentration nor the development of radiosensitivity with time of incubation in O 2 gives evidence in CHO cells for two components of sensitization indicative of two sites or two mechanisms of action, as seen in some V79 sublines. 13 references, 4 figures

  19. Molecular mechanism of radiosensitization by nitro compounds

    International Nuclear Information System (INIS)

    Kagiya, T.; Wada, T.; Nishimoto, S.I.

    1984-01-01

    In this chapter a molecular mechanism of radiosensitization by electron-affinic nitro compounds is discussed, mainly on the basis of the results of the radiation-induced chemical studies of DNA-related compounds in aqueous solutions. In Section II the general aspects of the radiation chemistry of organic compounds in the absence and presence of oxygen in aqueous solution are shown in order to demonstrate characteristic differences between radiation chemical reactions in hypoxic and oxic cells. The effects of nitro compounds on the radiolysis yields of DNA-related compounds in aqueous solutions are described in Section III. In Section IV the retardation effects of misonidazole on the radiation chemical processes of DNA-related compounds are shown along with the reaction characteristics of misonidazole with hydroxyl radical ( . OH) and hydrated electron (e/sub aq/-bar) produced by the radiolysis of water. The promotion of radiation-induced oxidation of thymine into thymine glycol (TG) by nitro radiosensitizers in deoxygenated solution and the relations between the activity of nitro compound for the thymine glycol formation and the enhancement activity measured in vitro are described in Section V. Finally, the protection against radiation-induced damage of thymine by a sulfhydryl compound of glutathione and the ability of electron-affinic compounds to decompose the intracellular radioprotector are described in Section VI

  20. 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

    significant. Results: Our results demonstrated that [6]-Gingerol treatment induced a dose-dependent decrease in the cell viability. Compared with the vehicle control, the cell viabilities were 75.99 ± 3.56% and 43.06 ± 7.82% when the cells were exposed to 150 μg/mL and 300 μg/mL of [6]-Gingerol, respectively. Therefore, we observed a significant difference between the treatment groups; (P<0.01). Then, the effect of [6]-Gingerol (300 μg/mL) on cell radiosensitivity was evaluated. The clonogenic cell survival assay showed a significant difference between dose-survival curves of group (A) and (B), (P<0.05) and between the group (C) and (D), (P<0.05). Therefore, [6]-Gingerol treatment increased the radiosensitivity of LNCaP cells. Conclusions: The results demonstrated that, besides inducing a dose-dependent apoptosis in LNCaP human prostate cancer cells, [6]-Gingerol showed a radiosensitizing activity. These findings suggests it potential as candidate phytochemical agent for combined therapy for prostate cancer. (author)

  1. 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

    significant. Results: Our results demonstrated that [6]-Gingerol treatment induced a dose-dependent decrease in the cell viability. Compared with the vehicle control, the cell viabilities were 75.99 ± 3.56% and 43.06 ± 7.82% when the cells were exposed to 150 μg/mL and 300 μg/mL of [6]-Gingerol, respectively. Therefore, we observed a significant difference between the treatment groups; (P<0.01). Then, the effect of [6]-Gingerol (300 μg/mL) on cell radiosensitivity was evaluated. The clonogenic cell survival assay showed a significant difference between dose-survival curves of group (A) and (B), (P<0.05) and between the group (C) and (D), (P<0.05). Therefore, [6]-Gingerol treatment increased the radiosensitivity of LNCaP cells. Conclusions: The results demonstrated that, besides inducing a dose-dependent apoptosis in LNCaP human prostate cancer cells, [6]-Gingerol showed a radiosensitizing activity. These findings suggests it potential as candidate phytochemical agent for combined therapy for prostate cancer. (author)

  2. MCM-2 expression differentiates potentially malignant verrucous lesions from oral carcinomas.

    Science.gov (United States)

    Niranjan, Kochli Channappa; Sarathy, Niharika Abhay; Alrani, Devendra

    2018-03-13

    Mcm-2 is a biomarker belonging to Mcm family of proteins which has rarely been used in oral potentially malignant and malignant lesions of the verrucous type. The objective of this study is to assess the expression of Mcm-2 in Normal Oral Mucosa (NM), Verrucous Hyperplasia (VH), Verrucous Carcinoma (VC) and Oral Squamous Cell Carcinoma (OSCC) and compare it with the clinicopathological characteristics. A total of 70 formalin fixed paraffin embedded tissue samples (10 cases of Normal Mucosa NM- Group A, 10 cases of Verrucous Hyperplasia- VH without Dysplasia- Group B, 10 cases of Verrucous Hyperplasia- VH with Dysplasia- Group C, 20 cases of Verrucous Carcinoma VC-Group D, 20 cases of Oral Squamous Cell Carcinoma OSCC- Group E) were subjected to immunohistochemistry with Mcm-2 antibody. Statistical analysis was carried out with various tests like ANOVA, Tukey HSD, Chi-Square and Shapiro-Wilk test by using the SPSS software. There was a significant difference in Mcm-2 expression with quantitative analysis among all the groups (p Mcm-2 may be a sensitive proliferation marker in oral potentially malignant and malignant lesions which may be useful for differentiating between VH with/ without dysplasia, VC and OSCC. Copyright © 2018. Published by Elsevier Inc.

  3. Recent advances and potential applications of modulated differential scanning calorimetry (mDSC) in drug development.

    Science.gov (United States)

    Knopp, Matthias Manne; Löbmann, Korbinian; Elder, David P; Rades, Thomas; Holm, René

    2016-05-25

    Differential scanning calorimetry (DSC) is frequently the thermal analysis technique of choice within preformulation and formulation sciences because of its ability to provide detailed information about both the physical and energetic properties of a substance and/or formulation. However, conventional DSC has shortcomings with respect to weak transitions and overlapping events, which could be solved by the use of the more sophisticated modulated DSC (mDSC). mDSC has multiple potential applications within the pharmaceutical field and the present review provides an up-to-date overview of these applications. It is aimed to serve as a broad introduction to newcomers, and also as a valuable reference for those already practising in the field. Complex mDSC was introduced more than two decades ago and has been an important tool for the quantification of amorphous materials and development of freeze-dried formulations. However, as discussed in the present review, a number of other potential applications could also be relevant for the pharmaceutical scientist. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Cultural and Intellectual Openness Differentially Relate to Social Judgments of Potential Work Partners.

    Science.gov (United States)

    Porter, Caitlin M; Parrigon, Scott E; Woo, Sang Eun; Saef, Rachel M; Tay, Louis

    2017-10-01

    This study investigates the differential functioning of cultural and intellectual openness (the two aspects of Openness to Experience) in relation to social cognitive processes by examining how they influence people's perceptions and interpretations of social information when deciding to initiate working relationships. Using a policy-capturing design, 681 adult participants were asked to rate their similarity to and preference to work with potential work partners characterized by varying nationalities and levels of work-related competence. Multilevel moderated mediation was conducted to simultaneously evaluate whether the indirect effects of potential work partners' characteristics (i.e., nationalities and levels of work-related competence) on work partner preference through perceived similarity were moderated by cultural and intellectual openness. Perceived similarity mediated the relationships between work partner nationality and work-related competence and participants' work partner preferences. Furthermore, the negative indirect effect of work partner nationality on work partner preference via perceived similarity was attenuated by cultural openness, and the positive indirect effect of work partner work-related competence on work partner preference via perceived similarity was strengthened by intellectual openness. Cultural and intellectual openness may have distinct functions that influence how people perceive, evaluate, and appreciate social information when making social judgments. © 2016 Wiley Periodicals, Inc.

  5. 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.

  6. KIH-802: 2-nitroimidazole-1-acetohydroxamate as a hypoxic cell radiosensitizer

    International Nuclear Information System (INIS)

    Hori, H.; Murayama, C.; Mori, T.; Shibamoto, Y.; Abe, M.; Onoyama, Y.; Inayama, S.

    1989-01-01

    We have identified potassium 2-nitroimidazole-1-acetohydroxamate (KIH-802) as a hypoxic cell radiosensitizer potentially superior to Miso. The water-soluble acetohydroxamates of 2-nitroimidazole (KIH-802; free acid 801) and 4-nitroimidazole (KIH-852) were designed, synthesized, and evaluated by in vitro and in vivo screening against EMT6 cells. Enhancement ratios of KIH-802 and 801 were 1.92 and 1.68, respectively, compared with 1.58 for MISO all at 1 mM. These acetohydroxamates are also expected to be more effective in vitro than SR-2508 based on our previous experiments. In vivo ERs of KIH-802, 801, and 852 were 1.75, 1.50, and 1.35, respectively, compared with 1.57 for MISO all at the same dose of 200 mg/kg. The data clearly show that the addition of an acetohydroxamic acid moiety to the 2-nitroimidazole skeleton can enhance radiosensitizing ability

  7. 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

  8. 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

  9. 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

  10. Depletion of histone demethylase KDM2A enhanced the adipogenic and chondrogenic differentiation potentials of stem cells from apical papilla

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Rui [Laboratory of Molecular Signaling and Stem Cells Therapy, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing 100050 (China); Yao, Rui [Department of Pediatrics, Stomatological Hospital of Nankai University, Tianjin 300041 (China); Du, Juan [Laboratory of Molecular Signaling and Stem Cells Therapy, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing 100050 (China); Wang, Songlin [Molecular Laboratory for Gene Therapy and Tooth Regeneration, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing 100050 (China); Department of Biochemistry and Molecular Biology, Capital Medical University School of Basic Medical Sciences, Beijing 100069 (China); Fan, Zhipeng, E-mail: zpfan@ccmu.edu.cn [Laboratory of Molecular Signaling and Stem Cells Therapy, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing 100050 (China)

    2013-11-01

    Mesenchymal stem cells (MSCs) are a reliable resource for tissue regeneration, but the molecular mechanism underlying directed differentiation remains unclear; this has restricted potential MSC applications. The histone demethylase, lysine (K)-specific demethylase 2A (KDM2A), is evolutionarily conserved and ubiquitously expressed members of the JmjC-domain-containing histone demethylase family. A previous study determined that KDM2A can regulate the cell proliferation and osteo/dentinogenic differentiation of MSCs. It is not known whether KDM2A is involved in the other cell lineages differentiation of MSCs. Here, we show that depletion of KDM2A by short hairpin RNAs can enhance adipogenic and chondrogenic differentiation potentials in human stem cells from apical papilla (SCAPs). We found that the stemness-related genes, SOX2, and the embryonic stem cell master transcription factor, NANOG were significantly increased after silence of KDM2A in SCAPs. Moreover, we found that knock-down of the KDM2A co-factor, BCOR also up-regulated the mRNA levels of SOX2 and NANOG. Furthermore, Chromatin immunoprecipitation assays demonstrate that silence of KDM2A increased the histone H3 Lysine 4 (H3K4) trimethylation in the SOX2 and NANOG locus and regulates its expression. In conclusion, our results suggested that depletion of KDM2A enhanced the adipogenic and chondrogenic differentiation potentials of SCAPs by up-regulated SOX2 and NANOG, BCOR also involved in this regulation as co-factor, and provided useful information to understand the molecular mechanism underlying directed differentiation in MSCs. - Highlights: • Depletion of KDM2A enhances adipogenic/chondrogenic differentiation in SCAPs. • Depletion of KDM2A enhances the differentiation of SCAPs by activate SOX2 and NANOG. • Silence of KDM2A increases histone H3 Lysine 4 trimethylation in SOX2 and NANOG. • BCOR is co-factor of KDM2A involved in the differentiation regulation.

  11. Depletion of histone demethylase KDM2A enhanced the adipogenic and chondrogenic differentiation potentials of stem cells from apical papilla

    International Nuclear Information System (INIS)

    Dong, Rui; Yao, Rui; Du, Juan; Wang, Songlin; Fan, Zhipeng

    2013-01-01

    Mesenchymal stem cells (MSCs) are a reliable resource for tissue regeneration, but the molecular mechanism underlying directed differentiation remains unclear; this has restricted potential MSC applications. The histone demethylase, lysine (K)-specific demethylase 2A (KDM2A), is evolutionarily conserved and ubiquitously expressed members of the JmjC-domain-containing histone demethylase family. A previous study determined that KDM2A can regulate the cell proliferation and osteo/dentinogenic differentiation of MSCs. It is not known whether KDM2A is involved in the other cell lineages differentiation of MSCs. Here, we show that depletion of KDM2A by short hairpin RNAs can enhance adipogenic and chondrogenic differentiation potentials in human stem cells from apical papilla (SCAPs). We found that the stemness-related genes, SOX2, and the embryonic stem cell master transcription factor, NANOG were significantly increased after silence of KDM2A in SCAPs. Moreover, we found that knock-down of the KDM2A co-factor, BCOR also up-regulated the mRNA levels of SOX2 and NANOG. Furthermore, Chromatin immunoprecipitation assays demonstrate that silence of KDM2A increased the histone H3 Lysine 4 (H3K4) trimethylation in the SOX2 and NANOG locus and regulates its expression. In conclusion, our results suggested that depletion of KDM2A enhanced the adipogenic and chondrogenic differentiation potentials of SCAPs by up-regulated SOX2 and NANOG, BCOR also involved in this regulation as co-factor, and provided useful information to understand the molecular mechanism underlying directed differentiation in MSCs. - Highlights: • Depletion of KDM2A enhances adipogenic/chondrogenic differentiation in SCAPs. • Depletion of KDM2A enhances the differentiation of SCAPs by activate SOX2 and NANOG. • Silence of KDM2A increases histone H3 Lysine 4 trimethylation in SOX2 and NANOG. • BCOR is co-factor of KDM2A involved in the differentiation regulation

  12. 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.

  13. 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.

  14. NKX2.2, PDX-1 and CDX-2 as potential biomarkers to differentiate well-differentiated neuroendocrine tumors.

    Science.gov (United States)

    Yang, Michelle X; Coates, Ryan F; Ambaye, Abiy; Cortright, Valerie; Mitchell, Jeannette M; Buskey, Alexa M; Zubarik, Richard; Liu, James G; Ades, Steven; Barry, Maura M

    2018-01-01

    Well-differentiated neuroendocrine tumors (NET) most frequently arise from the gastrointestinal tract (GI), pancreas, and lung. Patients often present as metastasis with an unknown primary, and the clinical management and outcome depend on multiple factors, including the accurate diagnosis with the tumor primary site. Determining the site of the NET with unknown primary remains challenging. Many biomarkers have been investigated in primary NETs and metastatic NETs, with heterogeneous sensitivity and specificity observed. We used high-throughput tissue microarray (TMA) and immunohistochemistry (IHC) with antibodies against a panel of transcriptional factors including NKX2.2, PDX-1, PTF1A, and CDX-2 on archived formalin-fixed paraffin-embedded NETs, and investigated the protein expression pattern of these transcription factors in 109 primary GI ( N  = 81), pancreatic ( N  = 17), and lung ( N  = 11) NETs. Differential expression pattern of these markers was observed. In the GI and pancreatic NETs ( N  = 98), NKX2.2, PDX-1, and CDX-2 were immunoreactive in 82 (84%), 14 (14%), and 52 (52%) cases, respectively. PDX-1 was expressed mainly in the small intestinal and appendiceal NETs, occasionally in the pancreatic NETs, and not in the colorectal NETs. All three biomarkers including NKX2.2, PDX-1, and CDX-2 were completely negative in lung NETs. PTF1A was expressed in all normal and neuroendocrine tumor cells. Our findings suggest that NKX2.2 was a sensitive and specific biomarker for the GI and pancreatic neuroendocrine tumors. We proposed that a panel of immunostains including NKX2.2, PDX-1, and CDX-2 may show diagnostic utility for the most common NETs.

  15. Potential Role of Metabolic Intervention in the Management of Advanced Differentiated Thyroid Cancer

    Directory of Open Access Journals (Sweden)

    Sri Harsha Tella

    2017-07-01

    Full Text Available Well-differentiated thyroid carcinoma (DTC is the most common endocrine malignancy that has an excellent prognosis with a 5-year survival rate of about 98%. However, approximately 50% of the patients with DTC who present with distant metastases (advanced DTC die from the disease within 5 years of initial diagnosis even after getting the appropriate therapy. Apart from recent advancements in chemotherapy agents, the potential role of metabolic interventions, including the use of metformin, ketogenic diet, and high-dose vitamin C in the management of advanced cancers have been investigated as a less toxic co-adjuvant therapies. The role of vitamin C has been of interest again after a preclinical mice study showed that high-dose vitamin C is selectively lethal to KRAS and BRAF mutant colorectal cancer cells by targeting the glutathione pathway. This raises the possibility of utilizing high-doses of vitamin C in the treatment of aDTC where KRAS and BRAF mutations are common. Similarly, alteration of cellular metabolism by low-carbohydrate ketogenic diets can be an important therapeutic strategy to selectively kill cancer cells that mainly survive on glycolysis. Among the potential adjuvant therapies proposed in this paper, metformin is the only agent that has shown benefit in human model of aDTC, the others have shown benefit but in preclinical/animal studies only and need to be further evaluated in large clinical trials. In conclusion, in addition to concurrent chemotherapy options, these metabolic interventions may have a great potential as co-adjuvant therapy in the management of aDTC.

  16. Polymers for IUdR radiosensitization of experimental glioblastoma

    International Nuclear Information System (INIS)

    Williams, Jeffery A.; Xuan Yuan; Brem, Henry

    1997-01-01

    Purpose: For the radiosensitization of human malignant gliomas, the potential of polymers for the local, controlled release of 5-iodo-2'-deoxyuridine (IUdR) remains unexplored. We tested a synthetic, implantable biodegradable polymer for the controlled in vitro release of IUdR, the resultant in vivo cellular labeling and subsequent radiosensitization of experimental intracranial (i.c.) U251 human glioblastoma xenografts. Materials and Methods: In vitro: Release: To measure release, increasing (10%, 30%, 50%) proportions of IUdR in synthetic [(poly(bis(p-carboxyphenoxy)-propane) (PCPP):sebacic acid (SA) (PCPP:SA ratio 20:80)] polymer discs (1x1x3 mm: 10 mg) were incubated in 0.1 M phosphate-buffered saline. The supernatant fractions were periodically removed and IUdR was measured via quantitative spectrophotometry. Radiosensitization: To confirm sensitization, U251 cells had 0 (control), 0.1, 1.0 or 10 uM exposure to IUdR for 72 hours and acute irradiation (0, 2.5, 5.0, or 10 Gy). Cells were trypsinized, replated and scored for colony formation. In vivo: To confirm in vivo i.c. release, 5 mice (male nu/nu, 6 weeks) had right frontal i.c. implantation of single polymer discs having 200 uCi 125-IUdR. The decay-corrected activity (cpm) vs. time (days) was serially measured via a calibrated, collimated scintillation detector. To measure i.c. diffusion of IUdR from polymers to GBM xenografts, groups of 5 mice had i.c. inoculation of 2 x 10 5 U251 cells (Day 0) and subsequent (Day 5) implantation of polymer discs having 50% IUdR loadings. Four or 8 days after IUdR polymer implantation, mice were sacrificed and the intact brains bearing the tumor and IUdR polymer were excised, fixed and cut coronally 0 (in plane of polymer), 1 or 2 mm anterior to the polymer in tumor using a cryostat. To quantify the percentage labeling of the tumor cells vs. distance from polymers via quantitative immunohistochemistry, triplicate high-powered fields of tumors were scored for nuclear IUd

  17. 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)

  18. 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

  19. Radiosensitivity of cultured insect cells: II. Diptera

    International Nuclear Information System (INIS)

    Koval, T.M.

    1983-01-01

    The radiosensitivity of five dipteran cell lines representing three mosquito genera and one fruit fly genus were examined. These lines are: (1) ATC-10, Aedes aegypti; (2) RU-TAE-14, Toxorhynchites amboinensis; (3) RU-ASE-2A, Anopheles stephensi; (4) WR69-DM-1, Drosophila melanogaster; and (5) WR69-DM-2, Drosophila melanogaster. Population doubling times for these lines range from approximately 16 to 48 hr. Diploid chromosome numbers are six for the mosquito cells and eight for the fruit fly cells D 0 values are 5.1 and 6.5 Gy for the Drosophila cell lines and 3.6, 6.2, and 10.2 Gy for the mosquito cell lines. The results of this study demonstrate that dipteran insect cells are a few times more resistant to radiation than mammalian cells, but not nearly as radioresistant as lepidopteran cells

  20. Diagnostic criteria of well differentiated thyroid tumor of uncertain malignant potential; a histomorphological and immunohistochemical appraisal.

    Science.gov (United States)

    Yassin, Fatma El-Zahraa Salah El-Deen

    2015-06-01

    Well differentiated thyroid tumor of uncertain malignant potential (WDT-UMP) represents a true "gray zone" of "follicular patterned" thyroid lesions, that needs to be characterized in order to outright the diagnosis of carcinoma and avoid unnecessary aggressive treatment. To emphasize on the histomorphological criteria for more accurate diagnosis of WDT-UMP. Also to compare the immunohistochemical expression of CK19 of WDT-UMP versus adenoma and papillary thyroid carcinoma (PTC). The study included 60 thyroid specimens; 18 WDT-UMPs, 24 PTC (18 classic variant and 6 follicular variants) and 18 benign thyroid lesions (8 adenoma, 6 Hashimoto's thyroiditis and 4 hyperplastic nodules). H&E stained sections were assessed according to the published major and minor criteria of malignancy in the thyroid. CK 19 immunostaining was examined and evaluated according to the proportion and intensity scores. We could detect the absence of nuclear inclusions, presence of characteristic nuclear groove, nuclear clearing, ovoid nuclei, nuclear crowdness, nuclear enlargement and pleomorphism as important reliable features for diagnosis of WDT-UMP with p value (<0.0001 for each). WDT-UMP showed moderate to strong CK 19 immunostaining with proportion scores 3 and 4; an intermediate expression profile; higher than adenoma and less than papillary carcinoma (p<0.0001). The constellations of both major and minor criteria of malignancy are important clues for WDT-UMP diagnosis which could be ascertained by CK 19 immunostaining. Copyright © 2015. Production and hosting by Elsevier B.V.

  1. 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)

  2. Radiosensitizing effect of nitric oxide in tumor cells and experimental tumors irradiated with gamma rays and proton beams; Efecto radiosensibilizador del oxido nitrico en celulas tumorales y en tumores experimentales irradiados con radiacion gamma y con haces de protones

    Energy Technology Data Exchange (ETDEWEB)

    Policastro, Lucia L; Duran, Hebe; Molinari, Beatriz L [Comision Nacional de Energia Atomica, General San Martin (Argentina). Dept. de Radiobiologia; Schuff, Juan A; Kreiner, Andres J; Burlon, Alejandro A; Debray, Mario E; Kesque, Jose M; Ozafran, Mabel J; Vazquez, Monica E [Comision Nacional de Energia Atomica, General San Martin (Argentina). Dept. de Fisica; Davidson, Jorge; Davidson, Miguel [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires (Argentina); Somacal, Hector R; Valda, Alejandro A [Universidad Nacional de General San Martin , Villa Ballester (Argentina). Escuela de Ciencia y Tecnologia

    2003-07-01

    Nitric oxide (NO) has been reported to be a radiosensitizer of mammalian cells under hypoxic conditions. In a previous study, we demonstrated an enhancement in radiation response induced by NO in mouse tumor cells under aerobic conditions, with an increasing effect as a function of malignancy. The aim of the present study was to evaluate the effect of NO in tumor cells and in experimental tumors irradiated with {gamma} rays and proton beams. Irradiations were performed with a {sup 137}Cs {gamma} source and with proton beams generated by the TANDAR accelerator. Tumor cells were treated with the NO donor DETA-NO and the sensitizer enhancement ratio (SER) was calculated using the {alpha} parameter of the survival curve fitted to the linear-quadratic model. Tumor cells irradiated with protons were radio sensitized by DETA-NO only in the more malignant cells irradiated with low LET protons (2.69{+-}0.08 keV/{mu}m). For higher LET protons there were no radiosensitizing effect. For human tumor cells pre-treated with DETA-NO and irradiated with {gamma} rays, a significantly greater effect was demonstrated in the malignant cells (MCF-7) as compared with the near normal cells (HBL-100). Moreover, a significant decrease in tumor growth was demonstrated in mice pre-treated with the NO donor spermine and irradiated with {gamma} rays and low LET protons as compared with mice irradiated without pre-treatment with the NO donor. In conclusion, we demonstrated a differential effect of NO as a radiosensitizer of malignant cells, both with {gamma} rays and low LET protons. This selectivity, coupled to the in vivo inhibition of tumor growth, is of great interest for the potential use of NO releasing agents in radiotherapy. (author)

  3. 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.

  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. Studies on radiosensitization of Escherichia coli cells by cis-platinum complexes

    International Nuclear Information System (INIS)

    Zimbrick, J.D.; Sukrochana, A.; Richmond, R.C.

    1979-01-01

    We recently reported that the antitumor drug cis-Pt(NH 3 ) 2 Cl 2 (cis-DDP) produces significant radiosensitization of anoxic E coli C cells. We have extended these studies to three other platinum drugs, all of which have been shown to be more effective antitumor drugs than cis-DDP. The drugs are: cis-dichloro bis(ethylene imine) Pt(II) (cis-DEP); cis-dichlorobicyclopentylamine Pt(II) (cis-PAD); and Pt-thymine blue (cis-PTB). Survival curve studies indicate that these drugs all produce greater anoxic radiosensitization of E coli C than cis-DDP at concentrations which are less toxic to the cells than similar concentrations of cis-DDP. If the cells are treated with any one of these drugs for two hours and then washed to remove the drug before irradiation, no detectable radiosensitization is found. We conclude that these drugs have the potential for being useful agents in combined modality therapy and that they warrant further study in mammalian systems

  6. 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.

  7. 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

  8. 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.

  9. 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

  10. Potential impact of climate-related changes is buffered by differential responses to recruitment and interactions

    KAUST Repository

    Menge, Bruce A.

    2011-08-01

    Detection of ecosystem responsiveness to climatic perturbations can provide insight into climate change consequences. Recent analyses linking phytoplankton abundance and mussel recruitment to the North Pacific Gyre Oscillation (NPGO) revealed a paradox. Despite large increases in mussel recruitment beginning in 2000, adult mussel responses were idiosyncratic by site and intertidal zone, with no response at one long-term site, and increases in the low zone (1.5% per year) and decreases in the mid zone (1.3% per year) at the other. What are the mechanisms underlying these differential changes? Species interactions such as facilitation by barnacles and predation are potential determinants of successful mussel colonization. To evaluate these effects, we analyzed patterns of barnacle recruitment, determined if predation rate covaried with the increase in mussel recruitment, and tested facilitation interactions in a field experiment. Neither magnitude nor season of barnacle recruitment changed meaningfully with site or zone from the 1990s to the 2000s. In contrast to the relationship between NPGO and local-scale mussel recruitment, relationships between local-scale patterns of barnacle recruitment and climate indices were weak. Despite differences in rates of prey recruitment and abundance of sea stars in 1990–1991, 1999–2000, and 2007–2008, predation rates were nearly identical in experiments before, during, and after 1999–2000. The facilitation experiment showed that mussels M. trossulus only became abundant when barnacle recruitment was allowed, when abundance of barnacles reached high abundance of ∼50% cover, and when mussel recruitment was sufficiently high. Thus, in the low zone minimal changes in mussel abundance despite sharply increased recruitment rates are consistent with the hypothesis that change in adult mussel cover was buffered by the relative insensitivity of barnacle recruitment to climatic fluctuations, and a resultant lack of change in

  11. Potential impact of climate-related changes is buffered by differential responses to recruitment and interactions

    KAUST Repository

    Menge, Bruce A.; Hacker, Sally D.; Freidenburg, Tess; Lubchenco, Jane; Craig, Ryan; Rilov, Gil; Noble, Mae Marjore; Richmond, Erin

    2011-01-01

    Detection of ecosystem responsiveness to climatic perturbations can provide insight into climate change consequences. Recent analyses linking phytoplankton abundance and mussel recruitment to the North Pacific Gyre Oscillation (NPGO) revealed a paradox. Despite large increases in mussel recruitment beginning in 2000, adult mussel responses were idiosyncratic by site and intertidal zone, with no response at one long-term site, and increases in the low zone (1.5% per year) and decreases in the mid zone (1.3% per year) at the other. What are the mechanisms underlying these differential changes? Species interactions such as facilitation by barnacles and predation are potential determinants of successful mussel colonization. To evaluate these effects, we analyzed patterns of barnacle recruitment, determined if predation rate covaried with the increase in mussel recruitment, and tested facilitation interactions in a field experiment. Neither magnitude nor season of barnacle recruitment changed meaningfully with site or zone from the 1990s to the 2000s. In contrast to the relationship between NPGO and local-scale mussel recruitment, relationships between local-scale patterns of barnacle recruitment and climate indices were weak. Despite differences in rates of prey recruitment and abundance of sea stars in 1990–1991, 1999–2000, and 2007–2008, predation rates were nearly identical in experiments before, during, and after 1999–2000. The facilitation experiment showed that mussels M. trossulus only became abundant when barnacle recruitment was allowed, when abundance of barnacles reached high abundance of ∼50% cover, and when mussel recruitment was sufficiently high. Thus, in the low zone minimal changes in mussel abundance despite sharply increased recruitment rates are consistent with the hypothesis that change in adult mussel cover was buffered by the relative insensitivity of barnacle recruitment to climatic fluctuations, and a resultant lack of change in

  12. 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)

  13. DEVELOPMENT OF SCIENTIFIC AND INFORMATIVE POTENTIAL OF STUDENTS IN THE TEACHING OF THE INVERSE PROBLEMS FOR DIFFERENTIAL EQUATIONS

    Directory of Open Access Journals (Sweden)

    Виктор Семенович Корнилов

    2017-12-01

    Full Text Available In article attention that when training in the inverse problems for differential equations at students scientific and cognitive potential develops is paid. Students realize that mathematical models of the inverse problems for differential equations find the application in economy, the industries, ecology, sociology, biology, chemistry, mathematician, physics, in researches of the processes and the phenomena occurring in water and earth’s environment, air and space.Attention of the reader that in training activity to the inverse problems for differential equations at students the scientific outlook, logical, algorithmic, information thinking, creative activity, independence and ingenuity develop is focused. Students acquire skills to apply knowledge of many physical and mathematical disciplines, to carry out the analysis of the received decision of the reverse task and to formulate logical outputs of application-oriented character. Solving the inverse problems for differential equations, students acquire new knowledge in the field of applied and calculus mathematics, informatics, natural sciences and other knowledge.

  14. Direct regulation of Gata3 expression determines the T helper differentiation potential of Notch

    NARCIS (Netherlands)

    Amsen, Derk; Antov, Andrey; Jankovic, Dragana; Sher, Alan; Radtke, Freddy; Souabni, Abdallah; Busslinger, Meinrad; McCright, Brent; Gridley, Thomas; Flavell, Richard A.

    2007-01-01

    CD4(+) T helper cells differentiate into T helper 1 (Th1) or Th2 effector lineages, which orchestrate immunity to different types of microbes. Both Th1 and Th2 differentiation can be induced by Notch, but what dictates which of these programs is activated in response to Notch is not known. By using

  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. 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

    Highlights: • Curcumin and trans-resveratrol can exert radioprotective or radiosensitizing effects. • The mechanisms underlying such dual action were elucidated using the PCC and G2-assay. • Radioprotection occurs in non-cycling cells exposed to curcumin and resveratrol. • Radiosensitization occurs in cycling cells exposed to the chemicals. • G2-checkpoint abrogation by the chemicals underlies the radiosensitizing mechanism. - Abstract: Curcumin and trans-resveratrol are well-known antioxidant polyphenols with radiomodulatory properties, radioprotecting non-cancerous cells while radiosensitizing tumor cells. This dual action may be the result of their radical scavenging properties and their effects on cell-cycle checkpoints that are activated in response to radiation-induced chromosomal damage. It could be also caused by their effect on regulatory pathways with impact on detoxification enzymes, the up-regulation of endogenous protective systems, and cell-cycle-dependent processes of DNA damage. This work aims to elucidate the mechanisms underlying the dual action of these polyphenols and investigates under which conditions they exhibit radioprotecting or radiosensitizing properties. The peripheral blood lymphocyte test system was used, applying concentrations ranging from 1.4 to 140 μM curcumin and 2.2 to 220 μM trans-resveratrol. The experimental design focuses first on their radioprotective effects in non-cycling lymphocytes, as uniquely visualized using cell fusion-mediated premature chromosome condensation, excluding, thus, cell-cycle interference to repair processes and activation of checkpoints. Second, the radiosensitizing potential of these chemicals on the induction of chromatid breaks in cultured lymphocytes following G2-phase irradiation was evaluated by a standardized G2-chromosomal radiosensitivity predictive assay. This assay uses caffeine for G2-checkpoint abrogation and it was applied to obtain an internal control for radiosensitivity

  17. 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

    Highlights: • Curcumin and trans-resveratrol can exert radioprotective or radiosensitizing effects. • The mechanisms underlying such dual action were elucidated using the PCC and G2-assay. • Radioprotection occurs in non-cycling cells exposed to curcumin and resveratrol. • Radiosensitization occurs in cycling cells exposed to the chemicals. • G2-checkpoint abrogation by the chemicals underlies the radiosensitizing mechanism. - Abstract: Curcumin and trans-resveratrol are well-known antioxidant polyphenols with radiomodulatory properties, radioprotecting non-cancerous cells while radiosensitizing tumor cells. This dual action may be the result of their radical scavenging properties and their effects on cell-cycle checkpoints that are activated in response to radiation-induced chromosomal damage. It could be also caused by their effect on regulatory pathways with impact on detoxification enzymes, the up-regulation of endogenous protective systems, and cell-cycle-dependent processes of DNA damage. This work aims to elucidate the mechanisms underlying the dual action of these polyphenols and investigates under which conditions they exhibit radioprotecting or radiosensitizing properties. The peripheral blood lymphocyte test system was used, applying concentrations ranging from 1.4 to 140 μM curcumin and 2.2 to 220 μM trans-resveratrol. The experimental design focuses first on their radioprotective effects in non-cycling lymphocytes, as uniquely visualized using cell fusion-mediated premature chromosome condensation, excluding, thus, cell-cycle interference to repair processes and activation of checkpoints. Second, the radiosensitizing potential of these chemicals on the induction of chromatid breaks in cultured lymphocytes following G2-phase irradiation was evaluated by a standardized G2-chromosomal radiosensitivity predictive assay. This assay uses caffeine for G2-checkpoint abrogation and it was applied to obtain an internal control for radiosensitivity

  18. The Differential Hormonal Milieu of Morning versus Evening May Have an Impact on Muscle Hypertrophic Potential.

    Directory of Open Access Journals (Sweden)

    Simon D Burley

    Full Text Available Substantial gains in muscle strength and hypertrophy are clearly associated with the routine performance of resistance training. What is less evident is the optimal timing of the resistance training stimulus to elicit these significant functional and structural skeletal muscle changes. Therefore, this investigation determined the impact of a single bout of resistance training performed either in the morning or evening upon acute anabolic signalling (insulin-like growth factor-binding protein-3 (IGFBP-3, myogenic index and differentiation and catabolic processes (cortisol. Twenty-four male participants (age 21.4±1.9yrs, mass 83.7±13.7kg with no sustained resistance training experience were allocated to a resistance exercise group (REP. Sixteen of the 24 participants were randomly selected to perform an additional non-exercising control group (CP protocol. REP performed two bouts of resistance exercise (80% 1RM in the morning (AM: 0800 hrs and evening (PM: 1800 hrs, with the sessions separated by a minimum of 72 hours. Venous blood was collected immediately prior to, and 5 min after, each resistance exercise and control sessions. Serum cortisol and IGFBP-3 levels, myogenic index, myotube width, were determined at each sampling period. All data are reported as mean ± SEM, statistical significance was set at P≤0.05. As expected a significant reduction in evening cortisol concentration was observed at pre (AM: 98.4±10.5, PM: 49.8±4.4 ng/ml, P0.05. Timing of resistance training regimen in the evening appears to augment some markers of hypertrophic potential, with elevated IGFBP-3, suppressed cortisol and a superior cellular environment. Further investigation, to further elucidate the time course of peak anabolic signalling in morning vs evening training conditions, are timely.

  19. The Differential Hormonal Milieu of Morning versus Evening May Have an Impact on Muscle Hypertrophic Potential.

    Science.gov (United States)

    Burley, Simon D; Whittingham-Dowd, Jayde; Allen, Jeremy; Grosset, Jean-Francois; Onambele-Pearson, Gladys L

    2016-01-01

    Substantial gains in muscle strength and hypertrophy are clearly associated with the routine performance of resistance training. What is less evident is the optimal timing of the resistance training stimulus to elicit these significant functional and structural skeletal muscle changes. Therefore, this investigation determined the impact of a single bout of resistance training performed either in the morning or evening upon acute anabolic signalling (insulin-like growth factor-binding protein-3 (IGFBP-3), myogenic index and differentiation) and catabolic processes (cortisol). Twenty-four male participants (age 21.4±1.9yrs, mass 83.7±13.7kg) with no sustained resistance training experience were allocated to a resistance exercise group (REP). Sixteen of the 24 participants were randomly selected to perform an additional non-exercising control group (CP) protocol. REP performed two bouts of resistance exercise (80% 1RM) in the morning (AM: 0800 hrs) and evening (PM: 1800 hrs), with the sessions separated by a minimum of 72 hours. Venous blood was collected immediately prior to, and 5 min after, each resistance exercise and control sessions. Serum cortisol and IGFBP-3 levels, myogenic index, myotube width, were determined at each sampling period. All data are reported as mean ± SEM, statistical significance was set at P≤0.05. As expected a significant reduction in evening cortisol concentration was observed at pre (AM: 98.4±10.5, PM: 49.8±4.4 ng/ml, P0.05). Timing of resistance training regimen in the evening appears to augment some markers of hypertrophic potential, with elevated IGFBP-3, suppressed cortisol and a superior cellular environment. Further investigation, to further elucidate the time course of peak anabolic signalling in morning vs evening training conditions, are timely.

  20. Tissue-engineered skin preserving the potential of epithelial cells to differentiate into hair after grafting.

    Science.gov (United States)

    Larouche, Danielle; Cuffley, Kristine; Paquet, Claudie; Germain, Lucie

    2011-03-01

    The aim of this study was to evaluate whether tissue-engineered skin produced in vitro was able to sustain growth of hair follicles in vitro and after grafting. Different tissues were designed. Dissociated newborn mouse keratinocytes or newborn mouse hair buds (HBs) were added onto dermal constructs consisting of a tissue-engineered cell-derived matrix elaborated from either newborn mouse or adult human fibroblasts cultured with ascorbic acid. After 7-21 days of maturation at the air-liquid interface, no hair was noticed in vitro. Epidermal differentiation was observed in all tissue-engineered skin. However, human fibroblast-derived tissue-engineered dermis (hD) promoted a thicker epidermis than mouse fibroblast-derived tissue-engineered dermis (mD). In association with mD, HBs developed epithelial cyst-like inclusions presenting outer root sheath-like attributes. In contrast, epidermoid cyst-like inclusions lined by a stratified squamous epithelium were present in tissues composed of HBs and hD. After grafting, pilo-sebaceous units formed and hair grew in skin elaborated from HBs cultured 10-26 days submerged in culture medium in association with mD. However, the number of normal hair follicles decreased with longer culture time. This hair-forming capacity after grafting was not observed in tissues composed of hD overlaid with HBs. These results demonstrate that epithelial stem cells can be kept in vitro in a permissive tissue-engineered dermal environment without losing their potential to induce hair growth after grafting.

  1. Mesobuthus Venom-Derived Antimicrobial Peptides Possess Intrinsic Multifunctionality and Differential Potential as Drugs

    Directory of Open Access Journals (Sweden)

    Bin Gao

    2018-02-01

    Full Text Available Animal venoms are a mixture of peptides and proteins that serve two basic biological functions: predation and defense against both predators and microbes. Antimicrobial peptides (AMPs are a common component extensively present in various scorpion venoms (herein abbreviated as svAMPs. However, their roles in predation and defense against predators and potential as drugs are poorly understood. Here, we report five new venom peptides with antimicrobial activity from two Mesobuthus scorpion species. These α-helical linear peptides displayed highly bactericidal activity toward all the Gram-positive bacteria used here but differential activity against Gram-negative bacteria and fungi. In addition to the antibiotic activity, these AMPs displayed lethality to houseflies and hemotoxin-like toxicity on mice by causing hemolysis, tissue damage and inducing inflammatory pain. Unlike AMPs from other origins, these venom-derived AMPs seem to be unsuitable as anti-infective drugs due to their high hemolysis and low serum stability. However, MeuTXKβ1, a known two-domain Mesobuthus AMP, is an exception since it exhibits high activity toward antibiotic resistant Staphylococci clinical isolates with low hemolysis and high serum stability. The findings that the classical AMPs play predatory and defensive roles indicate that the multifunctionality of scorpion venom components is an intrinsic feature likely evolved by natural selection from microbes, prey and predators of scorpions. This definitely provides an excellent system in which one can study how a protein adaptively evolves novel functions in a new environment. Meantimes, new strategies are needed to remove the toxicity of svAMPs on eukaryotic cells when they are used as leads for anti-infective drugs.

  2. Radio-sensitivity and 40K, 3H, 14C levels in dark-striped field mice, apodemus agrarius coreae, as a potential biological monitor for enviro-radiation and radionuclides

    International Nuclear Information System (INIS)

    Kim, Hee Sun; Song, Seung Yeon; Kim, Eun Joo; Choi, Hoon; Shin, Suk Chul; Kim, Chong Soon; Nishimura, Y.

    2006-01-01

    To understand how environmental effects of radiation and radionuclides from radiation facilities relate to human beings, the development of an unmanned monitoring system is required. For the reasons of that, the International Atomic Energy Agency (IAEA) suggests a method to evaluate the effects of radiation emitted from radiation facilities on marine water, freshwater, and habitats for land animals and plants on its Technical Report Series 190, 288, and 332. Recently, International Commission on Radiological Protection (ICRP) Publication No. 91 (2003) was consecutively published to protect non-human animals and plants from environmental radiation and radioactive materials. This study examined the potential usefulness of dark-striped field mice as a biological indicator of enviro-radiation and radionuclides around nuclear power plants and radioactive waste storage facilities. For the purpose, dark-striped mice were collected in regions of Korea where there are no radiation facilities. Their external morphological characters and isoenzyme patterns were observed. As a result, the most dark-striped mice scattered in Korea are Apodemus agrarius coreae

  3. 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.

  4. Radiosensitization of hypoxic bacterial cells by nitroimidazoles of low lipophilicity: steady-state and rapid-mix studies

    International Nuclear Information System (INIS)

    Anderson, R.F.; Patel, K.B.; Sehmi, D.S.

    1981-01-01

    Radiosensitization of hypoxic bacterial cells by five 2-nitroimidazoles, with similar reduction potentials to misonidazole but having lower lipophilicites, has been measured in Escherichia coli AB 1157 and Streptococcus lactis 712. Sensitization efficiency progressively decreased with decreasing lepophilicity in E. coli but not in S. lactis. This difference is discussed in terms of the differing membrane properties of the two bacteria; E. coli resembled a multicompartment model, as would also be expected with mammalian cells. Rapid-mix experiments are described which show that the radiosensitization observed after experiments are described which show that the radiosensitization observed after preirradiation contact times between ca. 3 and 30 msec is dependent on the lipophilicity of the sensitizer, higher lipophilicity resulting in a lower contact time being required for radiosensitization. This result and the observation that a highly lipophilic compound affects only half the full oxygen enhancement level after short contact times suggest that part of the sensitization process occurs in a lipophilic compartment of the cell

  5. Wnt pathway reprogramming during human embryonal carcinoma differentiation and potential for therapeutic targeting

    International Nuclear Information System (INIS)

    Snow, Grace E; Kasper, Allison C; Busch, Alexander M; Schwarz, Elisabeth; Ewings, Katherine E; Bee, Thomas; Spinella, Michael J; Dmitrovsky, Ethan; Freemantle, Sarah J

    2009-01-01

    Testicular germ cell tumors (TGCTs) are classified as seminonas or non-seminomas of which a major subset is embryonal carcinoma (EC) that can differentiate into diverse tissues. The pluripotent nature of human ECs resembles that of embryonic stem (ES) cells. Many Wnt signalling species are regulated during differentiation of TGCT-derived EC cells. This study comprehensively investigated expression profiles of Wnt signalling components regulated during induced differentiation of EC cells and explored the role of key components in maintaining pluripotency. Human embryonal carcinoma cells were stably infected with a lentiviral construct carrying a canonical Wnt responsive reporter to assess Wnt signalling activity following induced differentiation. Cells were differentiated with all-trans retinoic acid (RA) or by targeted repression of pluripotency factor, POU5F1. A Wnt pathway real-time-PCR array was used to evaluate changes in gene expression as cells differentiated. Highlighted Wnt pathway genes were then specifically repressed using siRNA or stable shRNA and transfected EC cells were assessed for proliferation, differentiation status and levels of core pluripotency genes. Canonical Wnt signalling activity was low basally in undifferentiated EC cells, but substantially increased with induced differentiation. Wnt pathway gene expression levels were compared during induced differentiation and many components were altered including ligands (WNT2B), receptors (FZD5, FZD6, FZD10), secreted inhibitors (SFRP4, SFRP1), and other effectors of Wnt signalling (FRAT2, DAAM1, PITX2, Porcupine). Independent repression of FZD5, FZD7 and WNT5A using transient as well as stable methods of RNA interference (RNAi) inhibited cell growth of pluripotent NT2/D1 human EC cells, but did not appreciably induce differentiation or repress key pluripotency genes. Silencing of FZD7 gave the greatest growth suppression in all human EC cell lines tested including NT2/D1, NT2/D1-R1, Tera-1 and 833

  6. Well-differentiated papillary mesothelioma of tunica vaginalis testis of unknown malignant potential: Sonographic appearance.

    Science.gov (United States)

    Ko, K W S; Tse, K S; Shek, K W; Hau, M N; Ting, S H

    2017-10-09

    Paratesticular mesothelioma is a rare differential diagnosis in the presence of scrotal hydrocele. A 17-year-old boy presented with a 3-year history of progressive hydrocele. Sonography revealed a large left paratesticular mass within the hydrocele. Serum tumor markers were negative. Left hydrocelectomy was performed and pathological analysis of the epididymal mass revealed a well-differentiated papillary mesothelioma. We discuss the sonographic and pathological findings of this rare neoplasm. © 2017 Wiley Periodicals, Inc.

  7. IL-34 and CSF-1 display an equivalent macrophage differentiation ability but a different polarization potential

    OpenAIRE

    Boulakirba, Sonia; Pfeifer, Anja; Mhaidly, Rana; Obba, Sandrine; Goulard, Michael; Schmitt, Thomas; Chaintreuil, Paul; Calleja, Anne; Furstoss, Nathan; Orange, François; Lacas-Gervais, Sandra; Boyer, Laurent; Marchetti, Sandrine; Verhoeyen, Els; Luciano, Frederic

    2018-01-01

    CSF-1 and IL-34 share the CSF-1 receptor and no differences have been reported in the signaling pathways triggered by both ligands in human monocytes. IL-34 promotes the differentiation and survival of monocytes, macrophages and osteoclasts, as CSF-1 does. However, IL-34 binds other receptors, suggesting that differences exist in the effect of both cytokines. In the present study, we compared the differentiation and polarization abilities of human primary monocytes in response to CSF-1 or IL-...

  8. Physicochemical Control of Adult Stem Cell Differentiation: Shedding Light on Potential Molecular Mechanisms

    Science.gov (United States)

    2010-01-01

    stem - cell -based biomedical and therapeutic applications, including tissue engineering, requires an understanding of the cell-cell and cell-environment interactions. To this end, recent efforts have been focused on the manipulation of adult stem cell differentiation using inductive soluble factors, designing suitable mechanical environments, and applying noninvasive physical forces. Although each of these different approaches has been successfully applied to regulate stem cell differentiation, it would be of great interest and

  9. Impact of low oxygen tension on stemness, proliferation and differentiation potential of human adipose-derived stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jane Ru; Pingguan-Murphy, Belinda; Wan Abas, Wan Abu Bakar [Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia); Noor Azmi, Mat Adenan; Omar, Siti Zawiah [Department of Obstetrics and Gynaecology, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia); Chua, Kien Hui [Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur (Malaysia); Wan Safwani, Wan Kamarul Zaman, E-mail: wansafwani@um.edu.my [Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia)

    2014-05-30

    Highlights: • Hypoxia maintains the stemness of adipose-derived stem cells (ASCs). • ASCs show an increased proliferation rate under low oxygen tension. • Oxygen level as low as 2% enhances the chondrogenic differentiation potential of ASCs. • HIF-1α may regulate the proliferation and differentiation activities of ASCs under hypoxia. - Abstract: Adipose-derived stem cells (ASCs) have been found adapted to a specific niche with low oxygen tension (hypoxia) in the body. As an important component of this niche, oxygen tension has been known to play a critical role in the maintenance of stem cell characteristics. However, the effect of O{sub 2} tension on their functional properties has not been well determined. In this study, we investigated the effects of O{sub 2} tension on ASCs stemness, differentiation and proliferation ability. Human ASCs were cultured under normoxia (21% O{sub 2}) and hypoxia (2% O{sub 2}). We found that hypoxia increased ASC stemness marker expression and proliferation rate without altering their morphology and surface markers. Low oxygen tension further enhances the chondrogenic differentiation ability, but reduces both adipogenic and osteogenic differentiation potential. These results might be correlated with the increased expression of HIF-1α under hypoxia. Taken together, we suggest that growing ASCs under 2% O{sub 2} tension may be important in expanding ASCs effectively while maintaining their functional properties for clinical therapy, particularly for the treatment of cartilage defects.

  10. Endothelium trans differentiated from Wharton's jelly mesenchymal cells promote tissue regeneration: potential role of soluble pro-angiogenic factors.

    Science.gov (United States)

    Aguilera, Valeria; Briceño, Luis; Contreras, Hector; Lamperti, Liliana; Sepúlveda, Esperanza; Díaz-Perez, Francisca; León, Marcelo; Veas, Carlos; Maura, Rafael; Toledo, Jorge Roberto; Fernández, Paulina; Covarrubias, Ambart; Zuñiga, Felipe Andrés; Radojkovic, Claudia; Escudero, Carlos; Aguayo, Claudio

    2014-01-01

    Mesenchymal stem cells have a high capacity for trans-differentiation toward many adult cell types, including endothelial cells. Feto-placental tissue, such as Wharton's jelly is a potential source of mesenchymal stem cells with low immunogenic capacity; make them an excellent source of progenitor cells with a potential use for tissue repair. We evaluated whether administration of endothelial cells derived from mesenchymal stem cells isolated from Wharton's jelly (hWMSCs) can accelerate tissue repair in vivo. Mesenchymal stem cells were isolated from human Wharton's jelly by digestion with collagenase type I. Endothelial trans-differentiation was induced for 14 (hWMSC-End14d) and 30 (hWMSC-End30d) days. Cell phenotyping was performed using mesenchymal (CD90, CD73, CD105) and endothelial (Tie-2, KDR, eNOS, ICAM-1) markers. Endothelial trans-differentiation was demonstrated by the expression of endothelial markers and their ability to synthesize nitric oxide (NO). hWMSCs can be differentiated into adipocytes, osteocytes, chondrocytes and endothelial cells. Moreover, these cells show high expression of CD73, CD90 and CD105 but low expression of endothelial markers prior to differentiation. hWMSCs-End express high levels of endothelial markers at 14 and 30 days of culture, and also they can synthesize NO. Injection of hWMSC-End30d in a mouse model of skin injury significantly accelerated wound healing compared with animals injected with undifferentiated hWMSC or injected with vehicle alone. These effects were also observed in animals that received conditioned media from hWMSC-End30d cultures. These results demonstrate that mesenchymal stem cells isolated from Wharton's jelly can be cultured in vitro and trans-differentiated into endothelial cells. Differentiated hWMSC-End may promote neovascularization and tissue repair in vivo through the secretion of soluble pro-angiogenic factors.

  11. Cellular network entropy as the energy potential in Waddington's differentiation landscape

    Science.gov (United States)

    Banerji, Christopher R. S.; Miranda-Saavedra, Diego; Severini, Simone; Widschwendter, Martin; Enver, Tariq; Zhou, Joseph X.; Teschendorff, Andrew E.

    2013-01-01

    Differentiation is a key cellular process in normal tissue development that is significantly altered in cancer. Although molecular signatures characterising pluripotency and multipotency exist, there is, as yet, no single quantitative mark of a cellular sample's position in the global differentiation hierarchy. Here we adopt a systems view and consider the sample's network entropy, a measure of signaling pathway promiscuity, computable from a sample's genome-wide expression profile. We demonstrate that network entropy provides a quantitative, in-silico, readout of the average undifferentiated state of the profiled cells, recapitulating the known hierarchy of pluripotent, multipotent and differentiated cell types. Network entropy further exhibits dynamic changes in time course differentiation data, and in line with a sample's differentiation stage. In disease, network entropy predicts a higher level of cellular plasticity in cancer stem cell populations compared to ordinary cancer cells. Importantly, network entropy also allows identification of key differentiation pathways. Our results are consistent with the view that pluripotency is a statistical property defined at the cellular population level, correlating with intra-sample heterogeneity, and driven by the degree of signaling promiscuity in cells. In summary, network entropy provides a quantitative measure of a cell's undifferentiated state, defining its elevation in Waddington's landscape. PMID:24154593

  12. Skeletal myogenic differentiation of human urine-derived cells as a potential source for skeletal muscle regeneration.

    Science.gov (United States)

    Chen, Wei; Xie, Minkai; Yang, Bin; Bharadwaj, Shantaram; Song, Lujie; Liu, Guihua; Yi, Shanhong; Ye, Gang; Atala, Anthony; Zhang, Yuanyuan

    2017-02-01

    Stem cells are regarded as possible cell therapy candidates for skeletal muscle regeneration. However, invasive harvesting of those cells can cause potential harvest-site morbidity. The goal of this study was to assess whether human urine-derived stem cells (USCs), obtained through non-invasive procedures, can differentiate into skeletal muscle linage cells (Sk-MCs) and potentially be used for skeletal muscle regeneration. In this study, USCs were harvested from six healthy individuals aged 25-55. Expression profiles of cell-surface markers were assessed by flow cytometry. To optimize the myogenic differentiation medium, we selected two from four different types of myogenic differentiation media to induce the USCs. Differentiated USCs were identified with myogenic markers by gene and protein expression. USCs were implanted into the tibialis anterior muscles of nude mice for 1 month. The results showed that USCs displayed surface markers with positive staining for CD24, CD29, CD44, CD73, CD90, CD105, CD117, CD133, CD146, SSEA-4 and STRO-1, and negative staining for CD14, CD31, CD34 and CD45. After myogenic differentiation, a change in morphology was observed from 'rice-grain'-like cells to spindle-shaped cells. The USCs expressed specific Sk-MC transcripts and protein markers (myf5, myoD, myosin, and desmin) after being induced with different myogenic culture media. Implanted cells expressed Sk-MC markers stably in vivo. Our findings suggest that USCs are able to differentiate into the Sk-MC lineage in vitro and after being implanted in vivo. Thus, they might be a potential source for cell injection therapy in the use of skeletal muscle regeneration. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.

  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. Cyclin D1 in well differentiated thyroid tumour of uncertain malignant potential.

    Science.gov (United States)

    Lamba Saini, Monika; Weynand, Birgit; Rahier, Jacques; Mourad, Michel; Hamoir, Marc; Marbaix, Etienne

    2015-04-18

    Encapsulated follicular tumours with equivocal papillary thyroid carcinoma (PTC) type nuclear features continue to remain a challenge despite the recent attempts to classify these borderline lesions. The term 'well differentiated tumour of uncertain malignant potential (WDT-UMP)' was introduced to classify these tumours. The present study aimed to evaluate the role of a cell cycle regulator like cyclin D1 in these tumours along with assessment of other well established PTC markers like galectin-3, HBME-1, CK19. Thirteen cases of metastatic PTC, papillary microcarcinoma and follicular variant of PTC (FVPTC) were identified from a histological review of 510 cases. In addition, 13 cases of a subset of follicular adenomatoid nodules with focal areas showing nuclear features characteristic of PTC, identified as WDT-UMP, were also analyzed. Immunohistochemical analysis of galectin-3, HBME-1, CK19 and the proliferation markers Ki67 and cyclin D1 was performed. Lesions were analyzed for cyclin D1 gene amplification by fluorescent in-situ hybridization. All WDT-UMP lesions showed immunolabelling of cyclin D1, Ki67; 11/ 13 cases showed immunolabelling of CK19; 10/13 cases showed immunolabelling of HBME-1 and 4/13 cases showed immunolabelling of galectin-3. Surrounding benign adenomatoid areas showed no to faint focal staining in all thirteen cases of cyclin D1, HBME-1 and galectin-3. A low rate of cyclin D1 gene amplification was identified in a significant proportion of cells in the WDT-UMP lesions as compared to surrounding benign adenomatoid areas. Increased expression of cyclin D1 and amplification of its gene along with immunolabelling of HBME-1 in WDT-UMP lesions showing cytological features of papillary thyroid carcinoma within follicular adenomatoid nodules suggest that these areas could correspond to a precursor lesion of follicular variant of PTC. Overexpression of cyclin D1, associated with the amplification of the gene suggests that these WDT-UMP lesions are an

  15. 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)

  16. Radiosensitization by histone deacetylase inhibition in an osteosarcoma mouse model

    International Nuclear Information System (INIS)

    Blattmann, C.; University Children's Hospital of Heidelberg; Thiemann, M.; Stenzinger, A.

    2013-01-01

    Background: Osteosarcomas (OS) are highly malignant and radioresistant tumors. Histone deacetylase inhibitors (HDACi) constitute a novel class of anticancer agents. We sought to investigate the effect of combined treatment with suberoylanilide hydroxamic acid (SAHA) and radiotherapy in OS in vivo. Methods: Clonogenic survival of human OS cell lines as well as tumor growth delay of OS xenografts were tested after treatment with either vehicle, radiotherapy (XRT), SAHA, or XRT and SAHA. Tumor proliferation, necrosis, microvascular density, apoptosis, and p53/p21 were monitored by immunohistochemistry. The CD95 pathway was performed by flow cytometry, caspase (3/7/8) activity measurements, and functional inhibition of CD95 death signaling. Results: Combined treatment with SAHA and XRT markedly reduced the surviving fraction of OS cells as compared to XRT alone. Likewise, dual therapy significantly inhibited OS tumor growth in vivo as compared to XRT alone, reflected by reduced tumor proliferation, impaired angiogenesis, and increased apoptosis. Addition of HDACi to XRT led to elevated p53, p21, CD95, and CD95L expression. Inhibition of CD95 signaling reduced HDACi- and XRT-induced apoptosis. Conclusion: Our data show that HDACi increases the radiosensitivity of osteosarcoma cells at least in part via ligand-induced apoptosis. HDACi thus emerge as potentially useful treatment components of OS. (orig.)

  17. Radiosensitization by histone deacetylase inhibition in an osteosarcoma mouse model

    Energy Technology Data Exchange (ETDEWEB)

    Blattmann, C. [Olgahospital, Stuttgart (Germany). Paediatrie 5; University Children' s Hospital of Heidelberg (Germany). Dept. of Pediatric Oncology, Hematology and Immunology; Thiemann, M. [German Cancer Research Center (DKFZ), Heidelberg (Germany). Dept. of Radiotherapy, Molecular- and Translational Radiation Oncology; Stenzinger, A. [Heidelberg Univ. (Germany). Inst. of Pathology; and others

    2013-11-15

    Background: Osteosarcomas (OS) are highly malignant and radioresistant tumors. Histone deacetylase inhibitors (HDACi) constitute a novel class of anticancer agents. We sought to investigate the effect of combined treatment with suberoylanilide hydroxamic acid (SAHA) and radiotherapy in OS in vivo. Methods: Clonogenic survival of human OS cell lines as well as tumor growth delay of OS xenografts were tested after treatment with either vehicle, radiotherapy (XRT), SAHA, or XRT and SAHA. Tumor proliferation, necrosis, microvascular density, apoptosis, and p53/p21 were monitored by immunohistochemistry. The CD95 pathway was performed by flow cytometry, caspase (3/7/8) activity measurements, and functional inhibition of CD95 death signaling. Results: Combined treatment with SAHA and XRT markedly reduced the surviving fraction of OS cells as compared to XRT alone. Likewise, dual therapy significantly inhibited OS tumor growth in vivo as compared to XRT alone, reflected by reduced tumor proliferation, impaired angiogenesis, and increased apoptosis. Addition of HDACi to XRT led to elevated p53, p21, CD95, and CD95L expression. Inhibition of CD95 signaling reduced HDACi- and XRT-induced apoptosis. Conclusion: Our data show that HDACi increases the radiosensitivity of osteosarcoma cells at least in part via ligand-induced apoptosis. HDACi thus emerge as potentially useful treatment components of OS. (orig.)

  18. Differentiation of Equine Mesenchymal Stromal Cells into Cells of Neural Lineage: Potential for Clinical Applications

    Directory of Open Access Journals (Sweden)

    Claudia Cruz Villagrán

    2014-01-01

    Full Text Available Mesenchymal stromal cells (MSCs are able to differentiate into extramesodermal lineages, including neurons. Positive outcomes were obtained after transplantation of neurally induced MSCs in laboratory animals after nerve injury, but this is unknown in horses. Our objectives were to test the ability of equine MSCs to differentiate into cells of neural lineage in vitro, to assess differences in morphology and lineage-specific protein expression, and to investigate if horse age and cell passage number affected the ability to achieve differentiation. Bone marrow-derived MSCs were obtained from young and adult horses. Following demonstration of stemness, MSCs were neurally induced and microscopically assessed at different time points. Results showed that commercially available nitrogen-coated tissue culture plates supported proliferation and differentiation. Morphological changes were immediate and all the cells displayed a neural crest-like cell phenotype. Expression of neural progenitor proteins, was assessed via western blot or immunofluorescence. In our study, MSCs generated from young and middle-aged horses did not show differences in their ability to undergo differentiation. The effect of cell passage number, however, is inconsistent and further experiments are needed. Ongoing work is aimed at transdifferentiating these cells into Schwann cells for transplantation into a peripheral nerve injury model in horses.

  19. Paraquat-induced radiosensitization of mammalian cells

    International Nuclear Information System (INIS)

    Miller, R.C.; Fujikura, Toshio; Hiraoka, Toshio; Tenou, Hiromi.

    1983-06-01

    The herbicide, paraquat (methyl viologen, 1-1' dimethy1-4, 4'-bipyridinium dichloride), stimulates the production of superoxide anion (O 2 sup(-.)) in aerobic cells and therefore mimics some effects of ionizing radiation. In addition, concentrations of cellular glutathione are reduced by reaction with O 2 sup(-.). It is reported here that paraquat, toxic in its own right to aerobic cells, acts as a radiosensitizer when cells are exposed to nontoxic concentrations of the drug prior to and during irradiation. The radiomimetic effect of paraquat, alone and in combination with X-rays, was examined. Paraquat affects aerated cells (hamster lung V79 cells) in a dose-dependent manner. Doses in excess of 1 mM for two hours cause significant cell killing. In combination with radiation, sublethal doses of paraquat, given for two hours prior to irradiation, enhance the lethal effects of radiation. However, if cells are exposed to the same concentration of paraquat following irradiation, no additional lethal effect is observed. Paraquat is a useful tool to study the effects of O 2 sup(-.) and may lead to better understanding of the mechanisms of radiation-induced energy deposition in cells. (author)

  20. Radiosensitivity of protoplasts of orange (Citrus sinensis)

    International Nuclear Information System (INIS)

    Goldman, M.H.S.; Ando, A.

    1990-01-01

    Full text: The Radiation Genetics Section of the Centre for Nuclear Energy in Agriculture (CENA), University of Sao Paulo, is utilising both ''in vivo'' and ''in vitro'' methods for mutation induction in Citrus, cv. ''Pera'', aiming at resistance to citrus canker. The experiments carried out so far determined the methodology to isolate protoplasts and their sensitivity to gamma-rays. Regarding the culture of protoplasts from embryogenic callus, the best experimental conditions were: enzymatic digestion for 5 h on a medium containing cellulase (307.6 mg/10 ml), macerozyme (30.3 mg/10 ml), mannitol (328.0 mM) and sucrose (336.2 mM) as osmotic stabilisers. The isolation efficiency of 1.2x10 6 viable protoplasts/g will make it possible to use protoplasts in mutation breeding. To determine radiosensitivity of protoplasts, gamma-irradiation from 60 Co source was conducted 42 h after their isolation. This time interval is recommended because during this period protoplasts will reach the stage prior to or at the first mitotic division. Survivals were determined by metylen-blue dyeing, and the LD 50 was found to be around 37.5 Gy. Any difference compared with other authors might be due to different genotypes used or different methods of calculation of survival. (author)

  1. Radiosensitivity, radio-curability and DNA repair

    International Nuclear Information System (INIS)

    Vogin, G.

    2011-01-01

    Improvements in accuracy stand as the heart of the success of today's radiotherapy. The dose may be delivered with a sub millimetric accuracy, may also conform to complex shapes, or track external and internal organ motions. In parallel, we may increase the tumour's radio-curability by modulating the biological effects generated by ionizing radiation into the patient. It was precisely the topic of the 2009 Lucien-Mallet prize organized by the French Society for Radiation Oncology (SFRO) and the Centre Antoine-Beclere under the auspices of the Fondation de France. In this review we will precisely describe the integrated molecular response to ionizing radiations. Starting from early observations, we are going to introduce the concept of cellular radiosensitivity as the global response of the irradiated cell. We will then focus into the cell and especially its nucleus. We will describe here the most complex and deleterious radioinduced damages. In the next chapter, we will dissect the molecular pathway that aims to detect and repair the previous lesions. The last part of the review will finally deal with the diagnostic, prognostic and therapeutic impacts emerging from the alliance between clinical and molecular radiobiology. (author)

  2. Radiosensitivity study of cultured barley (hordeum vulgare)

    International Nuclear Information System (INIS)

    Wang Cailian; Shen Mei; Xu Gang; Zhao Kongnan; Chen Qiufang

    1991-07-01

    For studying the radioactivity, forty seven varieties of dormant barley seeds were irradiated with various doses (0 ∼ 400 Gy) of 137 Cs γ-rays. The results showed that the dose-effects relations of seedling growth inhibition could be fitted by an equation of F(D) = 1 - (1 - e -a 1 D ) N , and the dose-effects of cell-nucleus, the frequency of root tip cell with chromosome aberations and peroxidase isoenzyme band could be expressed by a linear regression equation Y = A + B · X. The radioactivity of naked barley was much higher than of covered barley. According to different radiosensitivities the varieties studied could be divided into five types i.e. extreme resistant, resistant, intermediate, sensitive, and extreme sensitive. The results also showed that there was close relationship between the DNA content of cell-nucleus, peroxidase isoenzyme zymogram and radioactivity. The radiosensitivty was proportional to the DNA content. The volume of cell-nucleus varied inversly as D 50 of nucleus volume and no obvious correlation with the D 50 of seedling growth inhibition

  3. Radiosensitivity of cultured insect cells: I. Lepidoptera

    International Nuclear Information System (INIS)

    Koval, T.M.

    1983-01-01

    The radiosensitivity of five lepidopteran insect cell lines representing five different genera has been investigated. These lines are: (1) TN-368, Trichoplusia ni; (2) IPLB-SF-1254, Spodoptera frugiperda; (3) IPLB-1075, Heliothis zea; (4) MRRL-CHl, clone GVl, Manduca sexta; and (5) IAL-PID2, Plodia interpunctella. The cell lines grew at different rates and had population doubling times that ranged from 19 to 52 hr. All of the lines are highly heteroploid and have approximate chromosome numbers near or above 100. The chromosomes are very small. All of the lines are extremely radioresistant; cell populations are able to recover from 260 kVp X-ray exposures up to and including 400 Gy, the highest dose examined. Cell survival curves were obtainable for only the TN-368 and IPLB-SF-1254 lines. The TN-368 cells displayed a biphasic survival response with D 0 , d/sub q/, and n values of 65.7 and 130.2 Gy, 9.0 and -36.1 Gy, and 1.2 and 0.8, respectively, for the steep and shallow portions of the curve. The IPLB-SF-1254 cells had a D 0 of 63.9 Gy. D/sub q/ of 19.0 Gy, and n value of 1.4. These studies provide definitive evidence of the radioresistance of lepidopteran cells, and suggest that this radioresistance is a characteristic of lepidopteran insects

  4. 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.

  5. Hyaluronan preserves the proliferation and differentiation potentials of long-term cultured murine adipose-derived stromal cells

    International Nuclear Information System (INIS)

    Chen, P.-Y.; Huang, Lynn L.H.; Hsieh, H.-J.

    2007-01-01

    For long-term culture, murine adipose-derived stromal cells (mADSCs) at latter passages demonstrated a marked decline in proliferative activity, exhibited senescent morphology and reduced differentiation potentials, particularly osteogenesis. To extend the lifespan of mADSCs, two culture conditions containing hyaluronan (HA) was compared in our study, one as a culture medium supplement (SHA), and the other where HA was pre-coated on culture surface (CHA). mADSCs cultivated with SHA exhibited a prolonged lifespan, reduced cellular senescence, and enhanced osteogenic potential compared to regular culture condition (control). Upon CHA treatment, mADSCs tended to form cell aggregates with gradual growth profiles, while their differentiation activities remained similar to SHA groups. After transferring mADSCs from CHA to control surface, they were shown to have an extended lifespan and an increase of osteogenic potential. Our results suggested that HA can be useful for preserving the proliferation and differentiation potentials of long-term cultured mADSCs

  6. 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.

  7. 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

  8. 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.)

  9. Novel radiosensitizers for locally advanced epithelial tumors: inhibition of the PI3K/Akt survival pathway in tumor cells and in tumor-associated endothelial cells as a novel treatment strategy?

    International Nuclear Information System (INIS)

    Riesterer, Oliver; Tenzer, Angela; Zingg, Daniel; Hofstetter, Barbara; Vuong, Van; Pruschy, Martin; Bodis, Stephan

    2004-01-01

    In locally advanced epithelial malignancies, local control can be achieved with high doses of radiotherapy (RT). Concurrent chemoradiotherapy can improve tumor control in selected solid epithelial adult tumors; however, treatment-related toxicity is of major concern and the therapeutic window often small. Therefore, novel pharmacologic radiosensitizers with a tumor-specific molecular target and a broad therapeutic window are attractive. Because of clonal heterogeneity and the high mutation rate of these tumors, combined treatment with single molecular target radiosensitizers and RT are unlikely to improve sustained local tumor control substantially. Therefore, radiosensitizers modulating entire tumor cell survival pathways in epithelial tumors are of potential clinical use. We discuss the preclinical efficacy and the mechanism of three different, potential radiosensitizers targeting the PTEN/PI3K/Akt survival pathway. These compounds were initially thought to act as single-target agents against growth factor receptors (PKI 166 and PTK 787) or protein kinase C isoforms (PKC 412). We describe an additional target for these compounds. PKI 166 (an epidermal growth factor [EGF] receptor inhibitor) and PKC 412, target the PTEN/PI3K/Akt pathway mainly in tumor cells, and PTK 787 (a vascular endothelial growth factor [VEGF] receptor inhibitor) in endothelial cells. Even for these broader range molecular radiosensitizers, the benefit could be restricted to human epithelial tumor cell clones with a distinct molecular profile. Therefore, these potential radiosensitizers have to be carefully tested in specific model systems before introduction in early clinical trials

  10. Determination of the interatomic potential from elastic differential cross sections at fixed energy: Functional sensitivity analysis approach

    International Nuclear Information System (INIS)

    Ho, T.; Rabitz, H.

    1989-01-01

    Elastic differential cross sections in atomic crossed beam experiments contain detailed information about the underlying interatomic potentials. The functional sensitivity density of the cross sections with respect to the potential δσ(θ)/δV(R) reveals such information and has been implemented in an iterative inversion procedure, analogous to that of the Newton--Raphson technique. The stability of the inversion is achieved with the use of the regularization method of Tikhonov and Miller. It is shown that given a set of well resolved and noise-free differential cross section data within a limited angular range and given a reasonable starting reference potential, the recovered potential accurately resembles the desired one in the important region, i.e., the region to which the scattering data are sensitive. The region of importance depends upon the collision energy relative to the well depth of the potential under study; usually a higher collision energy penetrates deeper into the repulsive part of the potential and thus accordingly yields a more accurate potential in that part. The inversion procedure produces also a quality function indicating the well determined radial region. Moreover, the extracted potential is quite independent of the functional form of the reference potential in contrast to curve fitting approaches. As illustrations, the model inert gas systems He--Ne and Ne--Ar have been considered. For collision energies within an order of magnitude of the associated potential well depth, the attractive part of the potential can be determined to high precision provided that scattering data at small enough angles are available

  11. IL-34 and CSF-1 display an equivalent macrophage differentiation ability but a different polarization potential.

    Science.gov (United States)

    Boulakirba, Sonia; Pfeifer, Anja; Mhaidly, Rana; Obba, Sandrine; Goulard, Michael; Schmitt, Thomas; Chaintreuil, Paul; Calleja, Anne; Furstoss, Nathan; Orange, François; Lacas-Gervais, Sandra; Boyer, Laurent; Marchetti, Sandrine; Verhoeyen, Els; Luciano, Frederic; Robert, Guillaume; Auberger, Patrick; Jacquel, Arnaud

    2018-01-10

    CSF-1 and IL-34 share the CSF-1 receptor and no differences have been reported in the signaling pathways triggered by both ligands in human monocytes. IL-34 promotes the differentiation and survival of monocytes, macrophages and osteoclasts, as CSF-1 does. However, IL-34 binds other receptors, suggesting that differences exist in the effect of both cytokines. In the present study, we compared the differentiation and polarization abilities of human primary monocytes in response to CSF-1 or IL-34. CSF-1R engagement by one or the other ligands leads to AKT and caspase activation and autophagy induction through expression and activation of AMPK and ULK1. As no differences were detected on monocyte differentiation, we investigated the effect of CSF-1 and IL-34 on macrophage polarization into the M1 or M2 phenotype. We highlighted a striking increase in IL-10 and CCL17 secretion in M1 and M2 macrophages derived from IL-34 stimulated monocytes, respectively, compared to CSF-1 stimulated monocytes. Variations in the secretome induced by CSF-1 or IL-34 may account for their different ability to polarize naïve T cells into Th1 cells. In conclusion, our findings indicate that CSF-1 and IL-34 exhibit the same ability to induce human monocyte differentiation but may have a different ability to polarize macrophages.

  12. Personality traits as potential susceptibility markers : Differential susceptibility to support among parents

    NARCIS (Netherlands)

    Slagt, M.; Dubas, J.S.; Denissen, J.J.A.; Deković, M.; van Aken, M.A.G.

    2015-01-01

    In this study, we examined whether parents are differentially susceptible to support from their spouse and adolescent child depending on their personality traits, and whether differences in susceptibility to support among parents, in turn, are linked to the quality of support parents give to their

  13. REALIZATION OF SCIENTIFIC AND EDUCATIONAL POTENTIAL OF TRAINING IN THE INVERSE PROBLEMSFOR THE DIFFERENTIAL EQUATIONS

    Directory of Open Access Journals (Sweden)

    В С Корнилов

    2016-12-01

    Full Text Available In article methodical aspects of training for the inverse problems for differential equations of students of higher education institutions of the physical and mathematical and natural-science directions of preparation are stated. The attention to expediency of development in students of scientific outlook allowing to acquire fundamental knowledge of methods and methodology of research of mathematical models of the inverse problems, to master the principles of the organization of theoretical and practical researches of the inverse problem, to create ideas of the inverse problems as universal tools of knowledge of world around is paid.In article attention that development of scientific outlook in training activity to the inverse problems for differential equations allows students to deep understanding of idea of integrity of the world, assimilation of disciplines of applied mathematics, disciplines from other data domains is paid. It is marked that in the course of such training in students lines of humanitarization take root. Students acquire skills to analyze the received solutions of the inverse problems for differential equations, to formulate logical outputs about an ecological status of air space, earth’s environment or the water environment, to apply results of solutions of the inverse problems for differential equations in the humanitarian analysis of applied researches.

  14. The yield of DNA double strand breaks determined after exclusion of those forming from heat-labile lesions predicts tumor cell radiosensitivity to killing.

    Science.gov (United States)

    Cheng, Yanlei; Li, Fanghua; Mladenov, Emil; Iliakis, George

    2015-09-01

    The radiosensitivity to killing of tumor cells and in-field normal tissue are key determinants of radiotherapy response. In vitro radiosensitivity of tumor- and normal-tissue-derived cells often predicts radiation response, but high determination cost in time and resources compromise utility as routine response-predictor. Efforts to use induction or repair of DNA double-strand-breaks (DSBs) as surrogate-predictors of cell radiosensitivity to killing have met with limited success. Here, we re-visit this issue encouraged by our recent observations that ionizing radiation (IR) induces not only promptly-forming DSBs (prDSBs), but also DSBs developing after irradiation from the conversion to breaks of thermally-labile sugar-lesions (tlDSBs). We employ pulsed-field gel-electrophoresis and flow-cytometry protocols to measure total DSBs (tDSB=prDSB+tlDSBs) and prDSBs, as well as γH2AX and parameters of chromatin structure. We report a fully unexpected and in many ways unprecedented correlation between yield of prDSBs and radiosensitivity to killing in a battery of ten tumor cell lines that is not matched by yields of tDSBs or γH2AX, and cannot be explained by simple parameters of chromatin structure. We propose the introduction of prDSBs-yield as a novel and powerful surrogate-predictor of cell radiosensitivity to killing with potential for clinical application. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  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. In vivo analysis of homing pattern and differentiation potential of cells deriving from embryonic and adult haematopoietic regions

    OpenAIRE

    Petrovic, Suzana

    2004-01-01

    The experimental work of this thesis addresses the questions of whether established cell lines injected into murine blastocysts find their way back home and seed preferentially at the site of their origin. Furthermore, can they change their fate and differentiate to unrelated cell types when exposed to the embryonic environment. This survey was based on the fact that different cell lines have different potentials in developing embryos, dependent on their cellular identity. The cell lines used...

  17. 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

  18. 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)

  19. 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)

  20. Downregulation of heat shock protein B8 decreases osteogenic differentiation potential of dental pulp stem cells during in vitro proliferation.

    Science.gov (United States)

    Flanagan, M; Li, C; Dietrich, M A; Richard, M; Yao, S

    2018-04-01

    Tissue-derived stem cells, such as dental pulp stem cells (DPSCs), reduce differentiation capability during in vitro culture. We found that cultured DPSCs reduce expression of heat shock protein B8 (HspB8) and GIPC PDZ domain containing family member 2 (Gipc2). Our objectives were to evaluate the changes in DPSC composition during in vitro proliferation and to determine whether HspB8 and Gipc2 have function in differentiation potential of DPSCs. Different passages of rat DPSCs were evaluated for changes in CD90+ and/or CD271+ stem cells and changes in osteogenic potential. Real-time RT-PCR and immunostaining were conducted to determine expression of HspB8 and Gipc2. Expression of the genes in DPSCs was knocked down by siRNA, followed by osteogenic induction to evaluate the function of the genes. About 90% of cells in the DPSC cultures were CD90+ and/or CD271+ cells without dramatic change during in vitro proliferation. The DPSCs at passages 3 to 5 (P3 to P5) possess strong osteogenic potential, but such potential was greatly reduced at later passages. Expression of HspB8 and Gipc2 was significantly reduced at P11 versus P3. Knock-down of HspB8 expression abolished osteogenic potential of the DPSCs, but knock-down of Gipc2 had no effect. CD90+ and CD271+ cells are the major components of DPSCs in in vitro culture. High-level expression of HspB8 was critical for maintaining differentiation potential of DPSCs. © 2017 John Wiley & Sons Ltd.

  1. Clinical experiences with the radiosensitizer Misonidazol

    International Nuclear Information System (INIS)

    Bamberg, M.; Scherer, C.; Tamulevicius, P.; Streffer, C.

    1981-01-01

    The principle of action of sensitizers with electron affinity is explained and the development of these radiosensitizing substances up to the clinical of Misonidazol (MIS; Ro-07-0582) is shown. With special regard to the pharmacokinetic action of this substance, the therapeutic effects of MIS were examined in ten patients with brain tumors of high malignancy (400 mg/m 2 ) and four patients with oesophageal carcinomas (1 g/m 2 ), all these patients having reached the clinical phase III. Four other patients with recurrent brain tumors received a dose of 1 g/m 2 of MIS before each irradiation. Apart from slight neurotoxic and gastrointestinal side effects, the applicated doses of MIS were generally well tolerated. Only in one case a generalized maculopapular exanthema developed which regressed completely within few days. No correlation could be found between the subjective side effects and the plasma values determined by means of high pressure liquid chromatography (HPLC). After one to four hours following oral application, the maximum plasma concentrations were measured, the half-life (T 1/2) varying in all patients between five and ten hours. It was not possible to demonstrate an influence of dexamethasone on the plasma concentration of half-life of MIS in the brain tumor patients. The cerebrospinal fluid concentrations of MIS which may be used as an index for the concentrations in brain tumors, are closely correlated with the corresponding plasma values. There was no correlation between MIS concentrations in plasma and saliva, so that the determination of MIS in the saliva cannot be recommended as a routine method for control examinations. (orig.) [de

  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. 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

  4. A Comparative Study to Evaluate Myogenic Differentiation Potential of Human Chorion versus Umbilical Cord Blood-derived Mesenchymal Stem Cells.

    Science.gov (United States)

    Bana, Nikoo; Sanooghi, Davood; Soleimani, Mansoureh; Hayati Roodbari, Nasim; Alavi Moghaddam, Sepideh; Joghataei, Mohammad Taghi; Sayahpour, Forough Azam; Faghihi, Faezeh

    2017-08-01

    Musculodegenerative diseases threaten the life of many patients in the world. Since drug administration is not efficient in regeneration of damaged tissues, stem cell therapy is considered as a good strategy to restore the lost cells. Since the efficiency of myogenic differentiation potential of human Chorion- derived Mesenchymal Stem Cells (C-MSCs) has not been addressed so far; we set out to evaluate myogenic differentiation property of these cells in comparison with Umbilical Cord Blood- derived Mesenchymal Stem Cells (UCB-MSCs) in the presence of 5-azacytidine. To do that, neonate placenta Umbilical Cord Blood were transferred to the lab. After characterization of the isolated cells using flowcytometry and multilineage differentiation capacity, the obtained Mesenchymal Stem Cells were cultured in DMEM/F12 supplemented with 2% FBS and 10μM of 5-azacytidine to induce myogenic differentiation. Real-time PCR and immunocytochemistry were used to assess the myogenic properties of the cells. Our data showed that C-MSCs and UCB-MSCs were spindle shape in morphology. They were positive for CD90, CD73 and CD44 antigens, and negative for hematopoietic markers. They also differentiated into osteoblast and adipoblast lineages. Real-time PCR results showed that the cells could express MyoD, desmin and α-MHC at the end of the first week (P<0.05). No significant upregulation was detected in the expression of GATA-4 in both groups. Immunocytochemical staining revealed the expression of Desmin, cTnT and α-MHC. Results showed that these cells are potent to differentiate into myoblast- like cells. An upregulation in the expression of some myogenic markers (desmin, α- MHC) was observed in C-MSCs in comparison with UCB-MSCs. Copyright © 2017. Published by Elsevier Ltd.

  5. Myogenic Differentiation Potential of Human Newborn Foreskin Stem Cells Combined with Polycaprolactone-Based Nanofiber

    Directory of Open Access Journals (Sweden)

    Ozge Sezin Somuncu

    2016-03-01

    Full Text Available A previous study performed by the authors of the current study revealed the characterization and differentiation of newly defined stem cells known as human newborn foreskin stem cells (hnFSSCs. According to their stem cell properties, this study aimed at investigating myogenic differentiation and related tissue engineering. Human newborn foreskin stem cells were characterized by flow cytometry. The results showed that hnFSSCs carries a noble prospective for myogenic differentiation and can be used as a beneficial method for muscle related diseases, including muscular dystrophy, neuromuscular disorders, muscle damages, muscle weakness, lesion formations, and other problems associated with tissue obtainability and multi-potency; these cells may be accepted as effortlessly accessible and functional, and even superior to other stem cell origins. Furthermore, hnFFSCs were also seeded onto 3D micro-wells and Polycaprolactone (PCL scaffolds in order to examine tissue development. Human newborn foreskin stem cells on PCL scaffolds showed good cell-cell integration, so that they may be thought as a stem cell basis for tissue engineering.

  6. Effects of sensitizers on cell respiration. 3. The effects of hypoxic cell radiosensitizers on oxidative metabolism and the radiation response of an in vitro tumour model

    Energy Technology Data Exchange (ETDEWEB)

    Durand, R E [Wisconsin Clinical Cancer Center, Madison (USA). Dept. of Human Oncology; Biaglow, J E; Greenstock, C L

    1978-06-01

    Physiological factors are important when considering the effects of radiosensitizers on the radiation response of complex systems such as multi-cellular spheroids. In this system, under conditions of unlimited nutrient supply, cells are rendered hypoxic by metabolism. Thus, using the spheroid system as an in vitro model of the tumour-cell microenvironment, we have determined the relative contribution of radiosensitization and respiratory effects of a number of electron-affinic sensitizers having potential clinical use. These studies are indicative of physiological responses at the cellular level, and suggest optimal drug administration schemes for obtaining maximal radiation response in vivo with hypoxic cell sensitizers.

  7. 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

  8. 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.

  9. Parotid radiosensitivity changes: a temporal relation to glandular circadian rhythms

    International Nuclear Information System (INIS)

    El-Mofty, S.K.; Hovenga, T.L.; Russell, J.E.; Simmons, D.J.

    1982-01-01

    The radiosensitivity of the rat parotid gland to X-radiation increased considerably towards the end of the daily light span (0800-2000 hours) and to a lesser extent before the onset of that period. The major sensitivity peak occurred at 1600 hours and coincides with a diurnal nadir in the rates of protein and RNA synthesis. The minor peak occurred at 0400 hours and was temporally related to a daily period of maximal secretory activity. It is suggested that suboptimal repair and secretion-linked cellular perturbations might contribute to the pathogenesis of the circadian increases in radiosensitivity of parotid cells. (author)

  10. 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.)

  11. Price dynamics of the financial markets using the stochastic differential equation for a potential double well

    Science.gov (United States)

    Lima, L. S.; Miranda, L. L. B.

    2018-01-01

    We have used the Itô's stochastic differential equation for the double well with additive white noise as a mathematical model for price dynamics of the financial market. We have presented a model which allows us to test within the same framework the comparative explanatory power of rational agents versus irrational agents, with respect to the facts of financial markets. We have obtained the mean price in terms of the β parameter that represents the force of the randomness term of the model.

  12. 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

  13. Stem cells from umbilical cord blood do have myogenic potential, with and without differentiation induction in vitro

    Directory of Open Access Journals (Sweden)

    Gollop Thomaz R

    2009-01-01

    Full Text Available Abstract The dystrophin gene, located at Xp21, codifies dystrophin, which is part of a protein complex responsible for the membrane stability of muscle cells. Its absence on muscle causes Duchenne Muscular Dystrophy (DMD, a severe disorder, while a defect of muscle dystrophin causes Becker Muscular Dystrophy (DMB, a milder disease. The replacement of the defective muscle through stem cells transplantation is a possible future treatment for these patients. Our objective was to analyze the potential of CD34+ stem cells from umbilical cord blood to differentiate in muscle cells and express dystrophin, in vitro. Protein expression was analyzed by Immunofluorescence, Western Blotting (WB and Reverse Transcriptase – Polymerase Chain Reaction (RT-PCR. CD34+ stem cells and myoblasts from a DMD affected patient started to fuse with muscle cells immediately after co-cultures establishment. Differentiation in mature myotubes was observed after 15 days and dystrophin-positive regions were detected through Immunofluorescence analysis. However, WB or RT-PCR analysis did not detect the presence of normal dystrophin in co-cultures of CD34+ and DMD or DMB affected patients' muscle cells. In contrast, some CD34+ stem cells differentiated in dystrophin producers' muscle cells, what was observed by WB, reinforcing that this progenitor cell has the potential to originate muscle dystrophin in vitro, and not just in vivo like reported before.

  14. X-ray induced alterations in the differentiation and mineralization potential of murine preosteoblastic cells

    Science.gov (United States)

    Hu, Yueyuan; Lau, Patrick; Baumstark-Khan, Christa; Hellweg, Christine E.; Reitz, Günther

    2012-05-01

    To evaluate the effects of ionizing radiation (IR) on murine preosteoblastic cell differentiation, we directed OCT-1 cells to the osteoblastic lineage by treatment with a combination of β-glycerophosphate (β-GP), ascorbic acid (AA), and dexamethasone (Dex). In vitro mineralization was evaluated based on histochemical staining and quantification of the hydroxyapatite content of the extracellular bone matrix. Expression of mRNA encoding Runx2, transforming growth factor β1 (TGF-β1), osteocalcin (OCN), and p21CDKN1A was analyzed. Exposure to IR reduced the growth rate and diminished cell survival of OCT-1 cells under standard conditions. Notably, calcium content analysis revealed that deposition of mineralized matrix increased significantly under osteogenic conditions after X-ray exposure in a time-dependent manner. In this study, higher radiation doses exert significant overall effects on TGF-β1, OCN, and p21CDKN1A gene expression, suggesting that gene expression following X-ray treatment is affected in a dose-dependent manner. Additionally, we verified that Runx2 was suppressed within 24 h after irradiation at 2 and 4 Gy. Although further studies are required to verify the molecular mechanism, our observations strongly suggest that treatment with IR markedly alters the differentiation and mineralization process of preosteoblastic cells.

  15. Exendin-4 induces cell adhesion and differentiation and counteracts the invasive potential of human neuroblastoma cells.

    Science.gov (United States)

    Luciani, Paola; Deledda, Cristiana; Benvenuti, Susanna; Squecco, Roberta; Cellai, Ilaria; Fibbi, Benedetta; Marone, Ilaria Maddalena; Giuliani, Corinna; Modi, Giulia; Francini, Fabio; Vannelli, Gabriella Barbara; Peri, Alessandro

    2013-01-01

    Exendin-4 is a molecule currently used, in its synthetic form exenatide, for the treatment of type 2 diabetes mellitus. Exendin-4 binds and activates the Glucagon-Like Peptide-1 Receptor (GLP-1R), thus inducing insulin release. More recently, additional biological properties have been associated to molecules that belong to the GLP-1 family. For instance, Peptide YY and Vasoactive Intestinal Peptide have been found to affect cell adhesion and migration and our previous data have shown a considerable actin cytoskeleton rearrangement after exendin-4 treatment. However, no data are currently available on the effects of exendin-4 on tumor cell motility. The aim of this study was to investigate the effects of this molecule on cell adhesion, differentiation and migration in two neuroblastoma cell lines, SH-SY5Y and SK-N-AS. We first demonstrated, by Extra Cellular Matrix cell adhesion arrays, that exendin-4 increased cell adhesion, in particular on a vitronectin substrate. Subsequently, we found that this molecule induced a more differentiated phenotype, as assessed by i) the evaluation of neurite-like protrusions in 3D cell cultures, ii) the analysis of the expression of neuronal markers and iii) electrophysiological studies. Furthermore, we demonstrated that exendin-4 reduced cell migration and counteracted anchorage-independent growth in neuroblastoma cells. Overall, these data indicate for the first time that exendin-4 may have anti-tumoral properties.

  16. New potential markers of in vitro tomato morphogenesis identified by mRNA differential display.

    Science.gov (United States)

    Torelli, A; Soragni, E; Bolchi, A; Petrucco, S; Ottonello, S; Branca, C

    1996-12-01

    The identification of plant genes involved in early phases of in vitro morphogenesis can not only contribute to our understanding of the processes underlying growth regulator-controlled determination, but also provide novel markers for evaluating the outcome of in vitro regeneration experiments. To search for such genes and to monitor changes in gene expression accompanying in vitro regeneration, we have adapted the mRNA differential display technique to the comparative analysis of a model system of tomato cotyledons that can be driven selectively toward either shoot or callus formation by means of previously determined growth regulator supplementations. Hormone-independent transcriptional modulation (mainly down-regulation) has been found to be the most common event, indicating that a non-specific reprogramming of gene expression quantitatively predominates during the early phases of in vitro culture. However, cDNA fragments representative of genes that are either down-regulated or induced in a programme-specific manner could also be identified, and two of them (G35, G36) were further characterized. One of these cDNA fragments, G35, corresponds to an mRNA that is down-regulated much earlier in callus- (day 2) than in shoot-determined explants (day 6). The other, G36, identifies an mRNA that is transiently expressed in shoot-determined explants only, well before any macroscopic signs of differentiation become apparent, and thus exhibits typical features of a morphogenetic marker.

  17. Potential role of herbal remedies in stem cell therapy: proliferation and differentiation of human mesenchymal stromal cells.

    Science.gov (United States)

    Udalamaththa, Vindya Lankika; Jayasinghe, Chanika Dilumi; Udagama, Preethi Vidya

    2016-08-11

    Stem cell therapy has revolutionized modern clinical therapy with the potential of stem cells to differentiate into many different cell types which may help to replace different cell lines of an organism. Innumerous trials are carried out to merge new scientific knowledge and techniques with traditional herbal extracts that may result in less toxic, affordable, and highly available natural alternative therapeutics. Currently, mesenchyamal stromal cell (MSC) lines are treated with individual and mixtures of crude herbal extracts, as well as with purified compounds from herbal extracts, to investigate the mechanisms and effects of these on stem cell growth and differentiation. Human MSCs (hMSCs) possess multilineage, i.e., osteogenic, neurogenic, adipogenic, chondrogenic, and myogenic, differentiation abilities. The proliferative and differentiation properties of hMSCs treated with herbal extracts have shown promise in diseases such as osteoporosis, neurodegenerative disorders, and other tissue degenerative disorders. Well characterized herbal extracts that result in increased rates of tissue regeneration may be used in both stem cell therapy and tissue engineering for replacement therapy, where the use of scaffolds and vesicles with enhanced attaching and proliferative properties could be highly advantageous in the latter. Although the clinical application of herbal extracts is still in progress due to the variability and complexity of bioactive constituents, standardized herbal preparations will strengthen their application in the clinical context. We have critically reviewed the proliferative and differentiation effects of individual herbal extracts on hMSCs mainly derived from bone marrow and elaborated on the plausible underlying mechanisms of action. To be fruitfully used in reparative and regenerative therapy, future directions in this area of study should (i) make use of hMSCs derived from different non-traditional sources, including medical waste material

  18. Chitosan scaffolds induce human dental pulp stem cells to neural differentiation: potential roles for spinal cord injury therapy.

    Science.gov (United States)

    Zhang, Jinlong; Lu, Xiaohui; Feng, Guijuan; Gu, Zhifeng; Sun, Yuyu; Bao, Guofeng; Xu, Guanhua; Lu, Yuanzhou; Chen, Jiajia; Xu, Lingfeng; Feng, Xingmei; Cui, Zhiming

    2016-10-01

    Cell-based transplantation strategies hold great potential for spinal cord injury (SCI) repair. Chitosan scaffolds have therapeutic benefits for spinal cord regeneration. Human dental pulp stem cells (DPSCs) are abundant available stem cells with low immunological incompatibility and can be considered for cell replacement therapy. The purpose of this study is to investigate the role of chitosan scaffolds in the neural differentiation of DPSCs in vitro and to assess the supportive effects of chitosan scaffolds in an animal model of SCI. DPSCs were incubated with chitosan scaffolds. Cell viability and the secretion of neurotrophic factors were analyzed. DPSCs incubated with chitosan scaffolds were treated with neural differentiation medium for 14 days and then neural genes and protein markers were analyzed by Western blot and reverse transcription plus the polymerase chain reaction. Our study revealed a higher cell viability and neural differentiation in the DPSC/chitosan-scaffold group. Compared with the control group, the levels of BDNF, GDNF, b-NGF, and NT-3 were significantly increased in the DPSC/chitosan-scaffold group. The Wnt/β-catenin signaling pathway played a key role in the neural differentiation of DPSCs combined with chitosan scaffolds. Transplantation of DPSCs together with chitosan scaffolds into an SCI rat model resulted in the marked recovery of hind limb locomotor functions. Thus, chitosan scaffolds were non-cytotoxic and provided a conducive and favorable microenvironment for the survival and neural differentiation of DPSCs. Transplantation of DPSCs might therefore be a suitable candidate for treating SCI and other neuronal degenerative diseases.

  19. Cytokine-free directed differentiation of human pluripotent stem cells efficiently produces hemogenic endothelium with lymphoid potential.

    Science.gov (United States)

    Galat, Yekaterina; Dambaeva, Svetlana; Elcheva, Irina; Khanolkar, Aaruni; Beaman, Kenneth; Iannaccone, Philip M; Galat, Vasiliy

    2017-03-17

    The robust generation of human hematopoietic progenitor cells from induced or embryonic pluripotent stem cells would be beneficial for multiple areas of research, including mechanistic studies of hematopoiesis, the development of cellular therapies for autoimmune diseases, induced transplant tolerance, anticancer immunotherapies, disease modeling, and drug/toxicity screening. Over the past years, significant progress has been made in identifying effective protocols for hematopoietic differentiation from pluripotent stem cells and understanding stages of mesodermal, endothelial, and hematopoietic specification. Thus, it has been shown that variations in cytokine and inhibitory molecule treatments in the first few days of hematopoietic differentiation define primitive versus definitive potential of produced hematopoietic progenitor cells. The majority of current feeder-free, defined systems for hematopoietic induction from pluripotent stem cells include prolonged incubations with various cytokines that make the differentiation process complex and time consuming. We established that the application of Wnt agonist CHIR99021 efficiently promotes differentiation of human pluripotent stem cells in the absence of any hematopoietic cytokines to the stage of hemogenic endothelium capable of definitive hematopoiesis. The hemogenic endothelium differentiation was accomplished in an adherent, serum-free culture system by applying CHIR99021. Hemogenic endothelium progenitor cells were isolated on day 5 of differentiation and evaluated for their endothelial, myeloid, and lymphoid potential. Monolayer induction based on GSK3 inhibition, described here, yielded a large number of CD31 + CD34 + hemogenic endothelium cells. When isolated and propagated in adherent conditions, these progenitors gave rise to mature endothelium. When further cocultured with OP9 mouse stromal cells, these progenitors gave rise to various cells of myeloid lineages as well as natural killer lymphoid, T

  20. Effect of thorium, cerium and lanthanium metals on the radiosensitivity of human osteoblasts

    International Nuclear Information System (INIS)

    Iwahara, Lucas Kiyoshi da Fonseca

    2016-01-01

    This work analyzed the effects of Th, Ce and La combinations on the human osteoblast proliferation. Due to the osteotropic potential of actinides and lanthanides, a human osteoblast cell line was used to evaluate the effects of metals on cell radiosensitivity using cell proliferation and total proteins as indicators. Assays were performed using cultures exposed to metal alone and in combination and to ionising radiation. It was not observed effects on proliferation for cultures exposed to the metals alone. Concerning the influence of the three elements on the radiosensitivity, it was seen that all three metals were able to interfere on this indicator, in a concentration dependent manner. Evaluating cultures exposed to binary mixtures (Th-Ce and Th-La) and a ternary mixture (Th-Ce-La), it was verified that there were chemical interactions between the metals, for the combinations tested. The results showed very strong antagonism on the inhibition of cell proliferation in cultures exposed to Th-La and Th- Ce-La combinations. Regarding the osteoblasts exposed to mixtures and to radiation it was seen an antagonistic effect on the cell proliferation in all tested combinations, and the Th-Ce combination with a higher degree. These results show that metal mixtures containing thorium, in association with ionising radiation, induced different effects on cell proliferation, regarding the exposure to the metals alone, suggesting the possibility that the combinations interfere on osteoblast radiosensitivity expressing the increase of the occupational hazard among workers involved with monazite sands. The results also indicate that the analysis of the effects of metal mixtures on human cells is a more realistic risk assessment in comparison with the analysis of risk for single elements. The work displays the need to development of risk assessment models that include the study of mixtures obtained in the work environment for the evaluation of cytotoxic and radiotoxic effects in

  1. 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 

  2. The K + - Nucleus Microscopic Optical Potential and Calculations of the Corresponding Differential Elastic and Total Reaction Cross Sections

    International Nuclear Information System (INIS)

    Zemlyanaya, E.V.; Lukyanov, K.V.; Lukyanov, V.K.; Hanna, K.M.

    2009-01-01

    The microscopic optical potential (OP) is calculated for the K+-meson scattering on the 12 C and 40 Ca nuclei at intermediate energies. This potential has no free parameters and based on the known kaon-nucleon amplitude and nuclear density distribution functions. Then, the Klein-Gordon equation is written in the form of the relativistic Schrodinger equation where terms quadratic in the potential was estimated can be neglected. The latter equations adapted to the considered task and solved numerically. The effect of revitalization is shown to play a significant role. A good agreement with the experimental data on differential elastic cross sections is obtained. However, to explain the data on total reaction cross sections the additional surface term of OP was introduced to account for influence of the peripheral nuclear reaction channels

  3. MANF Promotes Differentiation and Migration of Neural Progenitor Cells with Potential Neural Regenerative Effects in Stroke

    DEFF Research Database (Denmark)

    Tseng, Kuan-Yin; Anttila, Jenni E; Khodosevich, Konstantin

    2018-01-01

    die shortly after injury or are unable to arrive at the infarct boundary. In this study, we demonstrate for the first time that endogenous mesencephalic astrocyte-derived neurotrophic factor (MANF) protects NSCs against oxygen-glucose-deprivation-induced injury and has a crucial role in regulating NPC...... migration. In NSC cultures, MANF protein administration did not affect growth of cells but triggered neuronal and glial differentiation, followed by activation of STAT3. In SVZ explants, MANF overexpression facilitated cell migration and activated the STAT3 and ERK1/2 pathway. Using a rat model of cortical...... stroke, intracerebroventricular injections of MANF did not affect cell proliferation in the SVZ, but promoted migration of doublecortin (DCX)+ cells toward the corpus callosum and infarct boundary on day 14 post-stroke. Long-term infusion of MANF into the peri-infarct zone increased the recruitment...

  4. Neoplasms radiosensitivity: how to increase the efficiency of radiotherapy

    International Nuclear Information System (INIS)

    Calais, G.

    1991-01-01

    The hypoxia in the neoplasms is a radioresistance factor. This article is about the methods able to reduce the hypoxia in tumors: use of hyperbaric oxygen, radiosensitizers (as metronidazole), hyperthermia and modification of oxygen release in the tissues in modifying the blood flow and in reducing the hemoglobin affinity for oxygen [fr

  5. Radiosensitivity of drug-resistant human tumour xenografts

    International Nuclear Information System (INIS)

    Mattern, J.; Bak, M. Jr.; Volm, M.; Hoever, K.H.

    1989-01-01

    The radiosensitivity of three drug-resistant sublines of a human epidermoid lung carcinoma growing as xenografts in nude mice was investigated. Drug resistance to vincristine, actinomycin D and cisplatin was developed in vivo by repeated drug treatment. It was found that all three drug-resistant tumour lines were not cross-resistant to irradiation. (orig.) [de

  6. Enhancement of misonidazole radiosensitization by an inhibitor of glutathione biosynthesis

    International Nuclear Information System (INIS)

    Hodgkiss, R.J.; Middleton, R.W.

    1983-01-01

    A well known inhibitor of glutathione biosynthesis, buthione sulphoximine (S-n-butyl homocysteine sulphoximine, BSO) depletes non-protein sulphydryls (NPSH) in Chinese hamster cells in vitro, resulting in a marked increase in the radiosensitization efficiency of misonidazole. V79 379A Chinese hamster cells were maintained in suspension cultures and irradiated in monolayers using 250 kVp X-rays at a dose rate of 3.93 Gy/min. Radiosensitization by misonidazole alone gave results within 0.1 sensitizer enhancement ratio (s.e.r.) of the curve reported by Watts et al. (1980). GSH (2 mmol dm - 3 ) added to the extracellular medium resulted in a marked decrease in the radiosensitization efficiency of misonidazole, eliminating the effect at 0.1 mmol dm - 3 misonidazole (s.e.r. = 1.0 relative to nitrogen control). A marked enhancement of the radiosensitization by misonidazole was observed when the cells had been incubated with BSO (0.1 mmol dm - 3 ). BSO alone at this concentration gave s.e.r. = 1.17; misonidazole alone (0.1 mmol dm - 3 ) gave s.e.r. = 1.18 and misonidazole with BSO (both 0.1. mmol dm - 3 ) gave s.e.r. = 1.9. The BSO treatment gave little effect in aerated cells. The concentration of BSO needed to produce these effects in vitro is ca. 40-fold lower than doses tolerated by mice in repeated administrations. (U.K.)

  7. Radiosensitivity and parameters for its measurement in some cucurbits

    Energy Technology Data Exchange (ETDEWEB)

    Vishnoi, A.K.; Joshi, M.C. (Defence Research and Development Organization, Almora (India). Agricultural Research Unit)

    1981-12-01

    Treatment with gamma-rays resulted in a significant reduction in the germination percentage and root and shoot lengths in Luffa cylindrica (inn). M. Roem, Momordica charantia Linn. Lagenaria siceraria (Mol.) Standl. and Cylanthera pedata Schrad., but radiation had no significant effect on nuclear volume. Species having higher value of nuclear volume had more radiosensitivity.

  8. DNA repair and the genetic control of radiosensitivity in yeast

    International Nuclear Information System (INIS)

    Haynes, R.H.

    1975-01-01

    The following topics are discussed: advantages of yeasts for easily manipulated model systems for studies on molecular biology of eukaryotes; induction of x-ray-resistant mutants by radiations and chemicals; genetics of uv-sensitive mutants; loci of genes affecting radiosensitivity; gene interactions in multiple mutants; liquid-holding recovery; mitotic and meiotic recombination; and repair of yeast mitochondrial DNA

  9. 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

  10. Radio-sensitizing effect of ethyl caffeate on nasopharyngeal ...

    African Journals Online (AJOL)

    3Department of Clinical Laboratory, The 5th People's Hospital of Ji'nan, Ji'nan ... Purpose: To investigate the radio-sensitizing effect of ethyl caffeate (ETF) on naso-pharyngeal ... malignant solid tumors of head and neck which ... Excess irradiation could result in severe side .... protein bands were probed with corresponding.

  11. Voltammetry of hypoxic cells radiosensitizer etanidazole radical anion in water

    Czech Academy of Sciences Publication Activity Database

    Gál, Miroslav; Hromadová, Magdaléna; Pospíšil, Lubomír; Híveš, J.; Sokolová, Romana; Kolivoška, Viliam; Kocábová, Jana

    2010-01-01

    Roč. 78, č. 2 (2010), s. 118-123 ISSN 1567-5394 R&D Projects: GA ČR GP203/09/P502 Institutional research plan: CEZ:AV0Z40400503 Keywords : etanidazole * radiosensitizer * electron transfer * voltammetry Subject RIV: CG - Electrochemistry Impact factor: 3.520, year: 2010

  12. Radiosensitivity and parameters for its measurement in some cucurbits

    International Nuclear Information System (INIS)

    Vishnoi, A.K.; Joshi, M.C.

    1981-01-01

    Treatment with gamma-rays resulted in a significant reduction in the germination percentage and root and shoot lengths in Luffa cylindrica (inn). M. Roem, Momordica charantia Linn. Lagenaria siceraria (Mol.) Standl. and Cylanthera pedata Schrad., but radiation had no significant effect on nuclear volume. Species having higher value of nuclear volume had more radiosensitivity. (author)

  13. ATM-mediated Snail Serine 100 phosphorylation regulates cellular radiosensitivity

    International Nuclear Information System (INIS)

    Boohaker, Rebecca J.; Cui, Xiaoli; Stackhouse, Murray; Xu, Bo

    2013-01-01

    Purpose: Activation of the DNA damage responsive protein kinase ATM is a critical step for cellular survival in response to ionizing irradiation (IR). Direct targets of ATM regulating radiosensitivity remain to be fully investigated. We have recently reported that ATM phosphorylates the transcriptional repressor Snail on Serine 100. We aimed to further study the functional significance of ATM-mediated Snail phosphorylation in response to IR. Material and methods: We transfected vector-only, wild-type, the Serine 100 to alanine (S100A) or to glutamic acid (S100E) substitution of Snail into various cell lines. We assessed colony formation, γ-H2AX focus formation and the invasion index in the cells treated with or without IR. Results: We found that over-expression of the S100A mutant Snail in HeLa cells significantly increased radiosensitivity. Meanwhile the expression of S100E, a phospho-mimicking mutation, resulted in enhanced radio-resistance. Interestingly, S100E could rescue the radiosensitive phenotype in ATM-deficient cells. We also found that expression of S100E increased γ-H2AX focus formation and compromised inhibition of invasion in response to IR independent of cell survival. Conclusion: ATM-mediated Snail Serine 100 phosphorylation in response to IR plays an important part in the regulation of radiosensitivity

  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. 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. 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

  17. [Effect of KH2PO4 on the odonto- and osteogenic differentiation potential of human stem cells from apical papillae].

    Science.gov (United States)

    Wang, Yan-ping; Wu, Jin-tao; Wang, Zi-lu; Zheng, Yang-yu; Zhang, Guang-dong; Yu, Jin-hua

    2013-01-01

    To determine the effects of KH2PO4 on the odonto- and osteogenic differentiation potential of human stem cells from apical papillae (SCAP) in vitro. SCAP were isolated and cultured respectively in alpha minimum essential medium (α-MEM) or α-MEM containing 1.8 mmol/L KH2PO4. Alkaline phosphatase (ALP) activity, alizarin red staining, real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blotting were used to examine the odonto and osteogenic potential of SCAP in the two media. SCAP cultured in α-MEM containing 1.8 mmol/L KH2PO4 exhibited a higher ALP activity [(0.370 ± 0.013) Sigma unit×min(-1)×mg(-1)] at day 3 than control group [(0.285 ± 0.008) Sigma unit×min(-1)×mg(-1)] and KH2PO4-treated SCAP formed more calcified nodules at day 5 [(0.539 ± 0.007) µg/g] and day 7 [(1.617 ± 0.042) µg/g] than those in normal medium [(0.138 ± 0.037) µg/g, P odonto- and osteogenic markers were significantly up-regulated after the stimulation of KH2PO4 at day 3 and 7 respectively, as compared with control group. 1.8 mmol/L KH2PO4 can promote the odonto and osteogenic differentiation potential of human SCAP.

  18. Multi-capillary column-ion mobility spectrometry: a potential screening system to differentiate virgin olive oils.

    Science.gov (United States)

    Garrido-Delgado, Rocío; Arce, Lourdes; Valcárcel, Miguel

    2012-01-01

    The potential of a headspace device coupled to multi-capillary column-ion mobility spectrometry has been studied as a screening system to differentiate virgin olive oils ("lampante," "virgin," and "extra virgin" olive oil). The last two types are virgin olive oil samples of very similar characteristics, which were very difficult to distinguish with the existing analytical method. The procedure involves the direct introduction of the virgin olive oil sample into a vial, headspace generation, and automatic injection of the volatiles into a gas chromatograph-ion mobility spectrometer. The data obtained after the analysis by duplicate of 98 samples of three different categories of virgin olive oils, were preprocessed and submitted to a detailed chemometric treatment to classify the virgin olive oil samples according to their sensory quality. The same virgin olive oil samples were also analyzed by an expert's panel to establish their category and use these data as reference values to check the potential of this new screening system. This comparison confirms the potential of the results presented here. The model was able to classify 97% of virgin olive oil samples in their corresponding group. Finally, the chemometric method was validated obtaining a percentage of prediction of 87%. These results provide promising perspectives for the use of ion mobility spectrometry to differentiate virgin olive oil samples according to their quality instead of using the classical analytical procedure.

  19. Increasing the radiosensitivity of tumours in an hypoxic environment using inhibitors of the pentose phosphate pathway

    International Nuclear Information System (INIS)

    Sahasrabudhe, M.B.; Bhonsle, S.R.; Krishnamurti, K.; Tilak, B.D.

    1977-01-01

    Rapidly growing tumours contain few blood vessels in the tumour mass. Cells in such tumours obtain nutrients and oxygen from the periphery by diffusion, resulting in a diminishing oxygen and nutrient gradient from the periphery to centre of the tumour mass. In normal tissues, oxygen is utilized via a tricarboxylic acid (TCA) cycle; in tumour cells oxygen is utilized via a hexose monophosphate (HMP) pathway and through the TCA cycle at a 30% reduced level. Interference with the HMP pathway selectively inhibits the utilization of oxygen by tumour cells, thus increasing the availability of oxygen to hypoxic cells situated deeper in the tumour mass. This effect has been exploited for increasing the radiosensitivity of tumour cells situated in an hypoxic environment. The influence of sixteen potential antimetabolites on the HMP pathway has been studied. Of these, six compounds, namely, (1) 2-carboxy 5-hydroxymethyl thiophene, (2) the sodium salt of 2:5 dicarbethoxy 3:4 dihydroxy thiophene, (3) the dihydrazide of 2:5 dicarboxy thiophene, (4) the dihydrazide of 3:4 dimethoxy 2:5 dicarboxy thiophene, (5) trithiocyanuric acid, and (6) cyanuric trithioglycollic acid showed an inhibiting effect on the HMP pathway without any influence on the TCA cycle. Influence of administration of compounds (1), (2) and (4) prior to radiation on the growth of transplanted fibrosarcomas in mice has been studied and is reported here. These three compounds showed marked potentiation of radiosensitivity of tumours. (author)

  20. Differential effects of thioridazine enantiomers on action potential duration in rabbit papillary muscle

    DEFF Research Database (Denmark)

    Jensen, Ask Schou; Pennisi, Cristian Pablo; Sevcencu, Cristian

    2015-01-01

    with (+)-thioridazine. In this study we for the first time investigate the cardiotoxicity of the isolated thioridazine enantiomers and show their effects on ventricular repolarization. The effects of (+)-thioridazine, (-)-thioridazine, and racemate on the rabbit ventricular action potential duration (APD) were...... investigated in a randomized controlled blinded experiment. Action potentials were measured in papillary muscles isolated from 21 female rabbits, and the drug effect on 90% APD in comparison with control (DeltaDelta-APD90) was evaluated. Increasing concentrations of (+)-thioridazine and the racemate caused...

  1. Sexual differentiation in the distribution potential of northern jaguars (Panthera onca)

    Science.gov (United States)

    Boydston, Erin E.; Lopez Gonzalez, Carlos A.

    2005-01-01

    We estimated the potential geographic distribution of jaguars in the southwestern United States and northwestern Mexico by modeling the jaguar ecological niche from occurrence records. We modeled separately the distribution of males and females, assuming records of females probably represented established home ranges while male records likely included dispersal movements. The predicted distribution for males was larger than that for females. Eastern Sonora appeared capable for supporting male and female jaguars with potential range expansion into southeastern Arizona. New Mexico and Chihuahua contained environmental characteristics primarily limited to the male niche and thus may be areas into which males occasionally disperse.

  2. Effects of hormone treatment on chromosomal radiosensitivity of somatic and germ cells of Snell's dwarf mice

    International Nuclear Information System (INIS)

    Buul, P.P.W. van; Buul-Offers, S.C. van

    1988-01-01

    The X-ray induction of micronuclei and structural chromosomal aberrations was studied in bone-marrow cells of normal and dwarf mice in combination with thyroxin and/or prolactin treatment or otherwise. Hormone treatment clearly increased micronuclei induction but not chromosome breakage, suggesting that indirect effects were involved. Since no clear differences in the timing of the final stage of erythropoiesis could be found, it is likely that the indirect effects are mediated via the formation-differentiation kinetics of erythroblasts. The induction of reciprocal translocations by X-rays in stem cell spermatogonia of dwarf mice was lower than in normals and treatment with prolactin, growth hormone and/or thyroxin, did not influence the chromosomal radiosensitivity of spermatogonial cells. 19 refs.; 1 figure; 4 tabs

  3. Can Drugs Enhance Hypofractionated Radiotherapy? A Novel Method of Modeling Radiosensitization Using In Vitro Data

    Energy Technology Data Exchange (ETDEWEB)

    Ohri, Nitin; Dicker, Adam P. [Department of Radiation Oncology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Lawrence, Yaacov Richard, E-mail: yaacovla@gmail.com [Department of Radiation Oncology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Center for Translational Research in Radiation Oncology, Sheba Medical Center, Tel Hashomer (Israel)

    2012-05-01

    Purpose: Hypofractionated radiotherapy (hRT) is being explored for a number of malignancies. The potential benefit of giving concurrent chemotherapy with hRT is not known. We sought to predict the effects of combined modality treatments by using mathematical models derived from laboratory data. Methods and Materials: Data from 26 published clonogenic survival assays for cancer cell lines with and without the use of radiosensitizing chemotherapy were collected. The first three data points of the RT arm of each assay were used to derive parameters for the linear quadratic (LQ) model, the multitarget (MT) model, and the generalized linear quadratic (gLQ) model. For each assay and model, the difference between the predicted and observed surviving fractions at the highest tested RT dose was calculated. The gLQ model was fitted to all the data from each RT cell survival assay, and the biologically equivalent doses in 2-Gy fractions (EQD2s) of clinically relevant hRT regimens were calculated. The increase in cell kill conferred by the addition of chemotherapy was used to estimate the EQD2 of hRT along with a radiosensitizing agent. For comparison, this was repeated using conventionally fractionated RT regimens. Results: At a mean RT dose of 8.0 Gy, the average errors for the LQ, MT, and gLQ models were 1.63, 0.83, and 0.56 log units, respectively, favoring the gLQ model (p < 0.05). Radiosensitizing chemotherapy increased the EQD2 of hRT schedules by an average of 28% to 82%, depending on disease site. This increase was similar to the gains predicted for the addition of chemotherapy to conventionally fractionated RT. Conclusions: Based on published in vitro assays, the gLQ equation is superior to the LQ and MT models in predicting cell kill at high doses of RT. Modeling exercises demonstrate that significant increases in biologically equivalent dose may be achieved with the addition of radiosensitizing agents to hRT. Clinical study of this approach is warranted.

  4. The effect of BW12C on radiosensitivity and necrosis of murine tissues and tumours

    International Nuclear Information System (INIS)

    Stevens, G.; Hill, S.A.; Joiner, M.C.; Joiner, B.; Johns, H.; Williams, K.; Denekamp, J.

    1994-01-01

    BW12C is a drug that has the potential to induce normal tissue and tumour hypoxia by binding to haemoglobin, increasing its affinity for oxygen and thereby reducing oxygen availability to tissues. Initial results suggested that BW12C administration caused significant radioprotection of normal tissues and induced tumour necrosis, but variable results have been reported subsequently. This work was carried to extend the range of observations concerning the ability of BW12C to radioprotect normal tissues and tumours and to induce necrosis of tumours of the mouse. BW12C was administered as 70 mg/kg intravenous 15 min before irradiation of jejunum in CBA mice and of foot skin in WHT mice with single doses of 240 kVp X-rays while mice breathed gases of varying oxygen tensions. The radiosensitivities of these tissues were assessed by the crypt survival assay and the acute skin reaction, respectively. The radiosensitivity of CaNT tumours to single fraction irradiation was assessed by the regrowth delay assay following administration of single or multiple does of BW12C at varying times to air-breathing CBA mice. The radiation response was compared to the radiosensitivity of clamped tumours. The effect of BW12C alone on tumours was assessed by regrowth delay and histological examination for necrosis. Single or multiple doses of BW12C did not influence the radiosensitivity of CaNT tumours, although marked radioprotection could be induced by clamping the tumours during irradiation. Multiple doses of BW12C alone led to a slight increase in necrosis of the CaNT tumour but did not alter its growth rate. BW12C alone did not induce necrosis of the murine JT lymphoma. The results shown that BW12C did not have a significant effect as a radioprotective or necrotizing agent in these experimental systems. The reported differences in the radiomodifying effects of BW12C are probably tissue-specific and relate to complex biochemical and physiological interactions. 18 refs., 4 figs

  5. Dipyridamole Body Surface Potential Mapping: Noninvasive Differentiation of Syndrome X from Coronary Artery Disease

    Czech Academy of Sciences Publication Activity Database

    Boudík, F.; Anger, Z.; Aschermann, M.; Vojáček, J.; Tomečková, Marie

    2002-01-01

    Roč. 35, č. 3 (2002), s. 181-191 ISSN 0022-0736 R&D Projects: GA MZd IZ4038 Keywords : body surface potential mapping * dipyridamole * coronary artery disease * syndrome X Subject RIV: BD - Theory of Information Impact factor: 0.599, year: 2002

  6. Sexual differentiation in the distribution potential of northern jaguars (Panthera onca)

    Science.gov (United States)

    Erin E. Boydston; Carlos A. Lopez Gonzalez

    2005-01-01

    We estimated the potential geographic distribution of jaguars in the southwestern United States and northwestern Mexico by modeling the jaguar ecological niche from occurrence records. We modeled separately the distributions of males and females, assuming records of females probably represented established home ranges while male records likely included dispersal...

  7. Differential processing of social chemosignals obtained from potential partners in regards to gender and sexual orientation.

    Science.gov (United States)

    Lübke, Katrin T; Hoenen, Matthias; Pause, Bettina M

    2012-03-17

    On an individual level, human body odors carry information about whether a person is an eligible mate. The current studies investigate if body odors also transmit information about individuals being potential partners in more general terms, namely in regards to gender and sexual orientation. In study 1, 14 gay and 14 heterosexual men were presented with body odors obtained from potential partners (gay male and heterosexual female body odors, respectively) and heterosexual male body odor as a control. In study 2, 14 lesbian and 14 heterosexual women were presented with lesbian female and heterosexual male body odors representing body odors of potential partners, and heterosexual female body odor as a control. Central nervous processing was analyzed using chemosensory event-related potentials and current source density analysis (64-channel EEG recording). Gay and heterosexual men responded with shorter P2 latencies to the body odors of their preferred sexual partners, and lesbian women responded with shorter P2 latencies to body odors of their preferred gender. In response to heterosexual male body odors, lesbian women displayed the most pronounced P3 amplitude, and distinct neuronal activation in medial frontal and parietal neocortical areas. A similar pattern of neuronal activation was observed in gay men when presented with heterosexual male body odor. Both the early processing advantage (P2) for desirable partners' body odors as well as the enhanced evaluative processing (P3, CSD) of undesirable partners' body odors suggest that human body odors indeed carry information about individuals being potential partners in terms of gender and sexual orientation. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Noggin inactivation affects the number and differentiation potential of muscle progenitor cells in vivo

    Science.gov (United States)

    Costamagna, Domiziana; Mommaerts, Hendrik; Sampaolesi, Maurilio; Tylzanowski, Przemko

    2016-01-01

    Inactivation of Noggin, a secreted antagonist of Bone Morphogenetic Proteins (BMPs), in mice leads, among others, to severe malformations of the appendicular skeleton and defective skeletal muscle fibers. To determine the molecular basis of the phenotype, we carried out a histomorphological and molecular analysis of developing muscles Noggin−/− mice. We show that in 18.5 dpc embryos there is a marked reduction in muscle fiber size and a failure of nuclei migration towards the cell membrane. Molecularly, the absence of Noggin results in an increased BMP signaling in muscle tissue as shown by the increase in SMAD1/5/8 phosphorylation, concomitant with the induction of BMP target genes such as Id1, 2, 3 as well as Msx1. Finally, upon removal of Noggin, the number of mesenchymal Pax7+ muscle precursor cells is reduced and they are more prone to differentiate into adipocytes in vitro. Thus, our results highlight the importance of Noggin/BMP balance for myogenic commitment of early fetal progenitor cells. PMID:27573479

  9. * Tissue-Specific Extracellular Matrix Enhances Skeletal Muscle Precursor Cell Expansion and Differentiation for Potential Application in Cell Therapy.

    Science.gov (United States)

    Zhang, Deying; Zhang, Yong; Zhang, Yuanyuan; Yi, Hualin; Wang, Zhan; Wu, Rongpei; He, Dawei; Wei, Guanghui; Wei, Shicheng; Hu, Yun; Deng, Junhong; Criswell, Tracy; Yoo, James; Zhou, Yu; Atala, Anthony

    2017-08-01

    Skeletal muscle precursor cells (MPCs) are considered a key candidate for cell therapy in the treatment of skeletal muscle dysfunction due to injury, disease, or age. However, expansion of a sufficient number of functional skeletal muscle cells in vitro from a small tissue biopsy has been challenging due to changes in phenotypic expression of these cells under traditional culture conditions. Thus, the aim of the study was to develop a better culture system for the expansion and myo-differentiation of MPCs that could further be used for therapy. For this purpose, we developed an ideal method of tissue decellularization and compared the ability of different matrices to support MPC growth and differentiation. Porcine-derived skeletal muscle and liver and kidney extracellular matrix (ECM) were generated by decellularization methods consisting of distilled water, 0.2 mg/mL DNase, or 5% fetal bovine serum. Acellular matrices were further homogenized, dissolved, and combined with a hyaluronic acid-based hydrogel decorated with heparin (ECM-HA-HP). The cell proliferation and myogenic differentiation capacity of human MPCs were assessed when grown on gel alone, ECM, or each ECM-HA-HP substrate. Human MPC proliferation was significantly enhanced when cultured on the ECM-HA-HP substrates compared to the other substrates tested, with the greatest proliferation on the muscle ECM-HA-HP (mECM-HA-HP) substrate. The number of differentiated myotubes was significantly increased on the mECM-HA-HP substrate compared to the other gel-ECM substrates, as well as the numbers of MPCs expressing specific myogenic cell markers (i.e., myosin, desmin, myoD, and myf5). In conclusion, skeletal mECM-HA-HP as a culture substrate provided an optimal culture microenvironment potentially due to its similarity to the in vivo environment. These data suggest a potential use of skeletal muscle-derived ECM gel for the expansion and differentiation of human MPCs for cell-based therapy for skeletal muscle

  10. A portable, differential amplifier for recording high frequency EEG signals and evoked potentials

    International Nuclear Information System (INIS)

    Donos, Cristian; Giurgiu, Liviu; Popescu, Aurel; Mocanu, Marian

    2010-01-01

    In a clinical context, EEG refers to recording the brain's spontaneous electric activity, using small electrodes placed on the scalp. The signals collected are electric 'potentials' measured between two electrodes. Usually, for a healthy adult, these signals have small voltage (10 μV to 100 μV) and frequencies in the 0-40 Hz range. In the scientific literature, there are mentioned EEG signals and evoked potentials that have higher frequencies (up to 600 Hz) and amplitudes lower than 500 ηV. For this reason, building an amplifier capable of recording EEG signals in the ηV range and with frequencies up to couple of kHz is necessary to continue research beyond 600 Hz. We designed a very low noise amplifier that is able to measure/record EEG signals in the ηV range over a very large frequency bandwidth (0.09 Hz -385 kHz).(Author)

  11. Central-field intermolecular potentials from the differential elastic scattering of H2(D2) by other molecules

    International Nuclear Information System (INIS)

    Kuppermann, Aron; Gordon, R.J.; Coggiola, M.J.

    1974-01-01

    Differential elastic scattering cross sections for the systems H 2 +O 2 , SF 6 , NH 3 , CO, and CH 4 and for D 2 +O 2 , SF 6 , and NH 3 have been obtained from crossed beam studies. In all cases, rapid quantum oscillations have been resolved which permit the determination of intermolecular potentiel parameters if a central-field assumption is adopted. These potentials were found to be independent of both the isotopic form of the hydrogen molecule, and the relative collision energy. As a result of this, and the ability of these spherical potentials to quantitatively describe the measured scattering, it is concluded that anisotropy effects do not seem important in these H 2 (D 2 ) systems

  12. Adapted physical exercise enhances activation and differentiation potential of satellite cells in the skeletal muscle of old mice.

    Science.gov (United States)

    Cisterna, Barbara; Giagnacovo, Marzia; Costanzo, Manuela; Fattoretti, Patrizia; Zancanaro, Carlo; Pellicciari, Carlo; Malatesta, Manuela

    2016-05-01

    During ageing, a progressive loss of skeletal muscle mass and a decrease in muscle strength and endurance take place, in the condition termed sarcopenia. The mechanisms of sarcopenia are complex and still unclear; however, it is known that muscle atrophy is associated with a decline in the number and/or efficiency of satellite cells, the main contributors to muscle regeneration. Physical exercise proved beneficial in sarcopenia; however, knowledge of the effect of adapted physical exercise on the myogenic properties of satellite cells in aged muscles is limited. In this study the amount and activation state of satellite cells as well as their proliferation and differentiation potential were assessed in situ by morphology, morphometry and immunocytochemistry at light and transmission electron microscopy on 28-month-old mice submitted to adapted aerobic physical exercise on a treadmill. Sedentary age-matched mice served as controls, and sedentary adult mice were used as a reference for an unperturbed control at an age when the capability of muscle regeneration is still high. The effect of physical exercise in aged muscles was further analysed by comparing the myogenic potential of satellite cells isolated from old running and old sedentary mice using an in vitro system that allows observation of the differentiation process under controlled experimental conditions. The results of this ex vivo and in vitro study demonstrated that adapted physical exercise increases the number and activation of satellite cells as well as their capability to differentiate into structurally and functionally correct myotubes (even though the age-related impairment in myotube formation is not fully reversed): this evidence further supports adapted physical exercise as a powerful, non-pharmacological approach to counteract sarcopenia and the age-related deterioration of satellite cell capabilities even at very advanced age. © 2016 Anatomical Society.

  13. 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.)

  14. Modification of the radiosensitivity of barley seed by post-treatment with caffeine

    International Nuclear Information System (INIS)

    Kesavan, P.C.; Nadkarni, S.

    1977-01-01

    The oxygen-dependent damage which developed in barley seeds with approximately 7.8 per cent moisture content disappeared after post-irradiation storage in vacuo for 48 hours at 40 0 C and for 24 hours at 50 0 C. When the duration of storage at 40 0 C was extended to 384 hours, oxygen-independent damage became potentiated. There was oxygen-dependent damage in seeds of approximately 13.3 per cent moisture content and after the seeds had been stored in vacuo at 50 0 C, the oxygen-independent damage began to increase by 168 hours, and it was significantly potentiated by 192 hours. Under these circumstances, caffeine acted as a radioprotector only as long as the precursors of oxic damage were present in the seeds. Once these sites were lost, caffeine acted only as a radiosensitizer. The oxygen-independent damage which increased with storage at high temperature was further potentiated by caffeine. (author)

  15. Inhibitor of differentiation 4 (Id4) is a potential tumor suppressor in prostate cancer

    International Nuclear Information System (INIS)

    Carey, Jason PW; Asirvatham, Ananthi J; Galm, Oliver; Ghogomu, Tandeih A; Chaudhary, Jaideep

    2009-01-01

    Inhibitor of differentiation 4 (Id4), a member of the Id gene family is also a dominant negative regulator of basic helix loop helix (bHLH) transcription factors. Some of the functions of Id4 appear to be unique as compared to its other family members Id1, Id2 and Id3. Loss of Id4 gene expression in many cancers in association with promoter hypermethylation has led to the proposal that Id4 may act as a tumor suppressor. In this study we provide functional evidence that Id4 indeed acts as a tumor suppressor and is part of a cancer associated epigenetic re-programming. Data mining was used to demonstrate Id4 expression in prostate cancer. Methylation specific polymerase chain reaction (MSP) analysis was performed to understand molecular mechanisms associated with Id4 expression in prostate cancer cell lines. The effect of ectopic Id4 expression in DU145 cells was determined by cell cycle analysis (3H thymidine incorporation and FACS), expression of androgen receptor, p53 and cyclin dependent kinase inhibitors p27 and p21 by a combination of RT-PCR, real time-PCR, western blot and immuno-cytochemical analysis. Id4 expression was down-regulated in prostate cancer. Id4 expression was also down-regulated in prostate cancer line DU145 due to promoter hyper-methylation. Ectopic Id4 expression in DU145 prostate cancer cell line led to increased apoptosis and decreased cell proliferation due in part by an S-phase arrest. In addition to S-phase arrest, ectopic Id4 expression in PC3 cells also resulted in prolonged G2/M phase. At the molecular level these changes were associated with increased androgen receptor (AR), p21, p27 and p53 expression in DU145 cells. The results suggest that Id4 acts directly as a tumor suppressor by influencing a hierarchy of cellular processes at multiple levels that leads to a decreased cell proliferation and change in morphology that is possibly mediated through induction of previously silenced tumor suppressors

  16. Inhibitor of differentiation 4 (Id4 is a potential tumor suppressor in prostate cancer

    Directory of Open Access Journals (Sweden)

    Carey Jason PW

    2009-06-01

    Full Text Available Abstract Background Inhibitor of differentiation 4 (Id4, a member of the Id gene family is also a dominant negative regulator of basic helix loop helix (bHLH transcription factors. Some of the functions of Id4 appear to be unique as compared to its other family members Id1, Id2 and Id3. Loss of Id4 gene expression in many cancers in association with promoter hypermethylation has led to the proposal that Id4 may act as a tumor suppressor. In this study we provide functional evidence that Id4 indeed acts as a tumor suppressor and is part of a cancer associated epigenetic re-programming. Methods Data mining was used to demonstrate Id4 expression in prostate cancer. Methylation specific polymerase chain reaction (MSP analysis was performed to understand molecular mechanisms associated with Id4 expression in prostate cancer cell lines. The effect of ectopic Id4 expression in DU145 cells was determined by cell cycle analysis (3H thymidine incorporation and FACS, expression of androgen receptor, p53 and cyclin dependent kinase inhibitors p27 and p21 by a combination of RT-PCR, real time-PCR, western blot and immuno-cytochemical analysis. Results Id4 expression was down-regulated in prostate cancer. Id4 expression was also down-regulated in prostate cancer line DU145 due to promoter hyper-methylation. Ectopic Id4 expression in DU145 prostate cancer cell line led to increased apoptosis and decreased cell proliferation due in part by an S-phase arrest. In addition to S-phase arrest, ectopic Id4 expression in PC3 cells also resulted in prolonged G2/M phase. At the molecular level these changes were associated with increased androgen receptor (AR, p21, p27 and p53 expression in DU145 cells. Conclusion The results suggest that Id4 acts directly as a tumor suppressor by influencing a hierarchy of cellular processes at multiple levels that leads to a decreased cell proliferation and change in morphology that is possibly mediated through induction of previously

  17. Differential Microbial Diversity in Drosophila melanogaster: Are Fruit Flies Potential Vectors of Opportunistic Pathogens?

    Directory of Open Access Journals (Sweden)

    Luis A. Ramírez-Camejo

    2017-01-01

    Full Text Available Drosophila melanogaster has become a model system to study interactions between innate immunity and microbial pathogens, yet many aspects regarding its microbial community and interactions with pathogens remain unclear. In this study wild D. melanogaster were collected from tropical fruits in Puerto Rico to test how the microbiota is distributed and to compare the culturable diversity of fungi and bacteria. Additionally, we investigated whether flies are potential vectors of human and plant pathogens. Eighteen species of fungi and twelve species of bacteria were isolated from wild flies. The most abundant microorganisms identified were the yeast Candida inconspicua and the bacterium Klebsiella sp. The yeast Issatchenkia hanoiensis was significantly more common internally than externally in flies. Species richness was higher in fungi than in bacteria, but diversity was lower in fungi than in bacteria. The microbial composition of flies was similar internally and externally. We identified a variety of opportunistic human and plant pathogens in flies such as Alcaligenes faecalis, Aspergillus flavus, A. fumigatus, A. niger, Fusarium equiseti/oxysporum, Geotrichum candidum, Klebsiella oxytoca, Microbacterium oxydans, and Stenotrophomonas maltophilia. Despite its utility as a model system, D. melanogaster can be a vector of microorganisms that represent a potential risk to plant and public health.

  18. 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.

  19. Selective targeting of brain tumors with gold nanoparticle-induced radiosensitization.

    Directory of Open Access Journals (Sweden)

    Daniel Y Joh

    Full Text Available Successful treatment of brain tumors such as glioblastoma multiforme (GBM is limited in large part by the cumulative dose of Radiation Therapy (RT that can be safely given and the blood-brain barrier (BBB, which limits the delivery of systemic anticancer agents into tumor tissue. Consequently, the overall prognosis remains grim. Herein, we report our pilot studies in cell culture experiments and in an animal model of GBM in which RT is complemented by PEGylated-gold nanoparticles (GNPs. GNPs significantly increased cellular DNA damage inflicted by ionizing radiation in human GBM-derived cell lines and resulted in reduced clonogenic survival (with dose-enhancement ratio of ~1.3. Intriguingly, combined GNP and RT also resulted in markedly increased DNA damage to brain blood vessels. Follow-up in vitro experiments confirmed that the combination of GNP and RT resulted in considerably increased DNA damage in brain-derived endothelial cells. Finally, the combination of GNP and RT increased survival of mice with orthotopic GBM tumors. Prior treatment of mice with brain tumors resulted in increased extravasation and in-tumor deposition of GNP, suggesting that RT-induced BBB disruption can be leveraged to improve the tumor-tissue targeting of GNP and thus further optimize the radiosensitization of brain tumors by GNP. These exciting results together suggest that GNP may be usefully integrated into the RT treatment of brain tumors, with potential benefits resulting from increased tumor cell radiosensitization to preferential targeting of tumor-associated vasculature.

  20. Metabolism and radiosensitization of 4,5-dimethylmisonidazole, a ring-substituted analog of misonidazole

    International Nuclear Information System (INIS)

    Born, J.L.; Smith, B.R.; Harper, N.; Koch, C.J.

    1992-01-01

    In the present study, methyl groups were added to the imidazole ring of misonidazole in order to hinder adduct formation with cellular molecules after reductive-activation of the compound. It was anticipated that this would substantially decrease the hypoxic-cell toxicity of the parent drug. The presence of the two methyl groups reduced the half-wave reduction potential of dimethyl misonidazole (DMM) by about 70 mV, so we expected that its radiosensitizing ability would also decrease. In direct comparison with misonidazole, DMM, at equimolar concentrations, showed dramatically reduced binding to cellular macromolecules under bioreductive conditions, both in vivo, using a liver perfusion system, and in vitro, using tissue culture cells incubated under extreme hypoxia. However, DMM was only moderately less toxic than the parent compound, and showed greatly diminished radiation sensitization capacity. Since the decrease in toxicity was much less than expected, and the decrease in radiosensitization was much more than expected, this compound may be an important drug for continuing studies on the mechanisms of radiation sensitization, binding and cytotoxicity caused by electron affinic drugs. (Author)

  1. 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

  2. Chemosensitivity and radiosensitivity testing of freshly explanted human tumour cells in vitro

    International Nuclear Information System (INIS)

    Wells, J.

    1977-10-01

    In this thesis, in vitro testing for the chemosensitivity and radiosensitivity of freshly explanted human tumour cells is described. The cells were incubated with anti-tumour drugs and either a 6-day growth test performed or a clonal growth test as a measure of survival of cell reproductive capacity. It was shown that if one aims to develop a suitable in vitro method for predicting the subsequent response of human tumour cells in situ to cytotoxic chemotherapy, the test procedure must be initiated before the explanted cells have undergone significant growth in vitro. The survival of the reproductive capacity of tumour cell explants following X-radiation was also studied. Using a 'feeder' layer technique, values for the survival curve parameter Dsub(q) were in the range 400-610 rad and the values for D 0 were in the range 120-160 rad. The shape of the X-ray survival curves did not change when cells were retested after repeated subculturing in vitro. Therefore, unlike chemosensitivity measured by the same biological end-point, radiosensitivity apparently does not change once cells have reached their maximum growth potential. (UK)

  3. Modulation of clonogenicity, growth, and radiosensitivity of three human epidermoid tumor cell lines by a fibroblastic environment

    International Nuclear Information System (INIS)

    Gery, Bernard; Little, John B.; Coppey, Jacques

    1996-01-01

    Purpose: To develop a model vitro system to examine the influence of fibroblasts on the growth and survival of human tumor cells after exposure to ionizing radiation. Methods and Materials: The cell system consists of three epidermoid carcinoma cell lines derived from head and neck tumors having differing growth potentials and intrinsic radiosensitivities, as well as a low passage skin fibroblast strain from a normal human donor. The tumor cells were seeded for five days prior to exposure to radiation: (a) in the presence of different numbers of fibroblasts, (b) in conditioned medium from stationary fibroblast cultures, and (c) on an extracted fibroblastic matrix. Results: When grown with fibroblasts, all three tumor cell lines showed increased clonogenicity and increased radioresistance. The radioprotective effect was maximal at a density of approximately 10 5 fibroblasts/100 mm Petri dish, and was greatest in the intrinsically radiosensitive tumor cell line. On the other hand, the effects of incubation with conditioned medium or on a fibroblastic matrix varied among the tumor cell lines. Thus, the protective effect afforded by coculture with fibroblasts must involve several cellular factors related to the fibroblast itself. Conclusions: These observations emphasize the importance of cultural conditions on the apparent radiosensitivity of human tumor cell lines, and suggest that the fibroblastic connective tissue enveloping the malignant cells should be considered when the aim is to establish a radiopredictive assay from surgical tumors fragments

  4. 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)

  5. 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.

  6. 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

  7. The effect of low static magnetic field on osteogenic and adipogenic differentiation potential of human adipose stromal/stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Marędziak, Monika, E-mail: monika.maredziak@gmail.com [Faculty of Veterinary Medicine, University of Environmental and Life Sciences, Wrocław (Poland); Wroclaw Research Centre EIT+, Wrocław (Poland); Śmieszek, Agnieszka, E-mail: smieszek.agnieszka@gmail.com [Wroclaw Research Centre EIT+, Wrocław (Poland); Faculty of Biology, University of Environmental and Life Sciences, Wrocław (Poland); Tomaszewski, Krzysztof A., E-mail: krtomaszewski@gmail.com [Department of Anatomy, Jagiellonian University Medical College, Krakow (Poland); Lewandowski, Daniel, E-mail: daniel.lewandowski@pwr.wroc.pl [Institute of Materials Science and Applied Mechanics, Wroclaw University of Technology, Wroclaw (Poland); Marycz, Krzysztof, E-mail: krzysztofmarycz@interia.pl [Wroclaw Research Centre EIT+, Wrocław (Poland); Faculty of Biology, University of Environmental and Life Sciences, Wrocław (Poland)

    2016-01-15

    The aim of this work was to investigate the effects of static magnetic field (SMF) on the osteogenic properties of human adipose derived mesenchymal stem cells (hASCs). In this study in seven days viability assay we examined the impact of SMF on cells proliferation rate, population doubling time, and ability to form single-cell derived colonies. We have also examined cells' morphology, ultrastructure and osteogenic properties on the protein as well as mRNA level. We established a complex approach, which enabled us to obtain information about SMF and hASCs potential in the context of differentiation into osteogenic and adipogenic lineages. We demonstrated that SMF enhances both viability and osteogenic properties of hASCs through higher proliferation factor and shorter population doubling time. We have also observed asymmetrically positioned nuclei and organelles after SMF exposition. With regards to osteogenic properties we observed increased levels of osteogenic markers i.e. osteopontin, osteocalcin and increased ability to form osteonodules with positive reaction to Alizarin Red dye. We have also shown that SMF besides enhancing osteogenic properties of hASCs, simultaneously decreases their ability to differentiate into adipogenic lineage. Our results clearly show a direct influence of SMF on the osteogenic potential of hASCs. These results provide key insights into the role of SMF on their cellular fate and properties. - Graphical abstract: Influence of static magnetic field on viability and differentiation properties of human adipose derived mesenchymal stem cells. Abbreviations: SMF – static magnetic field; hASCs – human adipose derived mesenchymal stem cells; PF – proliferation factor; PDT – population doubling time; CFU-E –> colony forming unit efficiency; OPN – osteopontin; OCL – osteocalcin; Col – collagen type I; BMP-2 – bone morphogenetic protein 2; Ca – calcium; P – phosphorus. - Highlights: • Effects of static

  8. The effect of low static magnetic field on osteogenic and adipogenic differentiation potential of human adipose stromal/stem cells

    International Nuclear Information System (INIS)

    Marędziak, Monika; Śmieszek, Agnieszka; Tomaszewski, Krzysztof A.; Lewandowski, Daniel; Marycz, Krzysztof

    2016-01-01

    The aim of this work was to investigate the effects of static magnetic field (SMF) on the osteogenic properties of human adipose derived mesenchymal stem cells (hASCs). In this study in seven days viability assay we examined the impact of SMF on cells proliferation rate, population doubling time, and ability to form single-cell derived colonies. We have also examined cells' morphology, ultrastructure and osteogenic properties on the protein as well as mRNA level. We established a complex approach, which enabled us to obtain information about SMF and hASCs potential in the context of differentiation into osteogenic and adipogenic lineages. We demonstrated that SMF enhances both viability and osteogenic properties of hASCs through higher proliferation factor and shorter population doubling time. We have also observed asymmetrically positioned nuclei and organelles after SMF exposition. With regards to osteogenic properties we observed increased levels of osteogenic markers i.e. osteopontin, osteocalcin and increased ability to form osteonodules with positive reaction to Alizarin Red dye. We have also shown that SMF besides enhancing osteogenic properties of hASCs, simultaneously decreases their ability to differentiate into adipogenic lineage. Our results clearly show a direct influence of SMF on the osteogenic potential of hASCs. These results provide key insights into the role of SMF on their cellular fate and properties. - Graphical abstract: Influence of static magnetic field on viability and differentiation properties of human adipose derived mesenchymal stem cells. Abbreviations: SMF – static magnetic field; hASCs – human adipose derived mesenchymal stem cells; PF – proliferation factor; PDT – population doubling time; CFU-E –> colony forming unit efficiency; OPN – osteopontin; OCL – osteocalcin; Col – collagen type I; BMP-2 – bone morphogenetic protein 2; Ca – calcium; P – phosphorus. - Highlights: • Effects of static

  9. [Differential effects of attention deficit/hyperactivity disorder subtypes in event-related potentials].

    Science.gov (United States)

    Tamayo-Orrego, Lukas; Osorio Forero, Alejandro; Quintero Giraldo, Lina Paola; Parra Sánchez, José Hernán; Varela, Vilma; Restrepo, Francia

    2015-01-01

    To better understand the neurophysiological substrates in attention deficit/hyperactivity disorder (ADHD), a study was performed on of event-related potentials (ERPs) in Colombian patients with inattentive and combined ADHD. A case-control, cross-sectional study was designed. The sample was composed of 180 subjects between 5 and 15 years of age (mean, 9.25±2.6), from local schools in Manizales. The sample was divided equally in ADHD or control groups and the subjects were paired by age and gender. The diagnosis was made using the DSM-IV-TR criteria, the Conners and WISC-III test, a psychiatric interview (MINIKID), and a medical evaluation. ERPs were recorded in a visual and auditory passive oddball paradigm. Latency and amplitude of N100, N200 and P300 components for common and rare stimuli were used for statistical comparisons. ADHD subjects show differences in the N200 amplitude and P300 latency in the auditory task. The N200 amplitude was reduced in response to visual stimuli. ADHD subjects with combined symptoms show a delayed P300 in response to auditory stimuli, whereas inattentive subjects exhibited differences in the amplitude of N100 and N200. Combined ADHD patients showed longer N100 latency and smaller N200-P300 amplitude compared to inattentive ADHD subjects. The results show differences in the event-related potentials between combined and inattentive ADHD subjects. Copyright © 2014 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  10. 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

  11. Differential Cytotoxic Potential of Silver Nanoparticles in Human Ovarian Cancer Cells and Ovarian Cancer Stem Cells

    Directory of Open Access Journals (Sweden)

    Yun-Jung Choi

    2016-12-01

    Full Text Available The cancer stem cell (CSC hypothesis postulates that cancer cells are composed of hierarchically-organized subpopulations of cells with distinct phenotypes and tumorigenic capacities. As a result, CSCs have been suggested as a source of disease recurrence. Recently, silver nanoparticles (AgNPs have been used as antimicrobial, disinfectant, and antitumor agents. However, there is no study reporting the effects of AgNPs on ovarian cancer stem cells (OvCSCs. In this study, we investigated the cytotoxic effects of AgNPs and their mechanism of causing cell death in A2780 (human ovarian cancer cells and OvCSCs derived from A2780. In order to examine these effects, OvCSCs were isolated and characterized using positive CSC markers including aldehyde dehydrogenase (ALDH and CD133 by fluorescence-activated cell sorting (FACS. The anticancer properties of the AgNPs were evaluated by assessing cell viability, leakage of lactate dehydrogenase (LDH, reactive oxygen species (ROS, and mitochondrial membrane potential (mt-MP. The inhibitory effect of AgNPs on the growth of ovarian cancer cells and OvCSCs was evaluated using a clonogenic assay. Following 1–2 weeks of incubation with the AgNPs, the numbers of A2780 (bulk cells and ALDH+/CD133+ colonies were significantly reduced. The expression of apoptotic and anti-apoptotic genes was measured by real-time quantitative reverse transcriptase polymerase chain reaction (qRT-PCR. Our observations showed that treatment with AgNPs resulted in severe cytotoxicity in both ovarian cancer cells and OvCSCs. In particular, AgNPs showed significant cytotoxic potential in ALDH+/CD133+ subpopulations of cells compared with other subpopulation of cells and also human ovarian cancer cells (bulk cells. These findings suggest that AgNPs can be utilized in the development of novel nanotherapeutic molecules for the treatment of ovarian cancers by specific targeting of the ALDH+/CD133+ subpopulation of cells.

  12. Differential effects of object-based attention on evoked potentials to fearful and disgusted faces.

    Science.gov (United States)

    Santos, Isabel M; Iglesias, Jaime; Olivares, Ela I; Young, Andrew W

    2008-04-01

    Event-related potentials (ERPs) were used to investigate the role of attention on the processing of facial expressions of fear and disgust. Stimuli consisted of overlapping pictures of a face and a house. Participants had to monitor repetitions of faces or houses, in separate blocks of trials, so that object-based attention was manipulated while spatial attention was kept constant. Faces varied in expression and could be either fearful or neutral (in the fear condition) or disgusted or neutral (in the disgust condition). When attending to faces, participants were required to signal repetitions of the same person, with the facial expressions being completely irrelevant to the task. Different effects of selective attention and different patterns of brain activity were observed for faces with fear and disgust expressions. Results indicated that the perception of fear from faces is gated by selective attention at early latencies, whereas a sustained positivity for fearful faces compared to neutral faces emerged around 160ms at central-parietal sites, independent of selective attention. In the case of disgust, ERP differences began only around 160ms after stimulus onset, and only after 480ms was the perception of disgust modulated by attention allocation. Results are interpreted in terms of different neural mechanisms for the perception of fear and disgust and related to the functional significance of these two emotions for the survival of the organism.

  13. Immunohistochemical Differentiation between Urothelial Papillomas and Papillary Neoplasms of Low Malignant Potential of the Urinary Bladder.

    Science.gov (United States)

    Alrashidy, Mohammed; Atef, Aliaa; Baky, Tarek Abdel

    2016-01-01

    Urothelial papilloma and non-invasive papillary carcinoma are common neoplasms of the urinary bladder. Distinguishing papillomas and papillary carcinomas, especially the low grade type, is often debatable on the basis of histological features alone. We investigated immunohistochemical expression of cytokeratin 20 (CK20), p53, and Ki-67 in a group of 20 urothelial papilloma cases and 30 noninvasive papillary neoplasms of low malignant potential (PNLMP) of the urinary bladder. Whole tissue sections were examined. Among the 30 carcinoma cases, 12 (40%) showed strong reactivity for the whole panel, 16 (53%) reacted positively for two markers, and 2 (7%) reacted just to one of them. Ki-67 was considered positive in 27 cases (90%) and p53 in 24 (80%), CK20 showed positive reactivity in 21 cases (70%). Only small percentages of papillomas were positive, and then only weakly. We concluded that the intense positivity of suspicious cells for at least one of these markers would confirm the presence of malignant changes and favours the diagnosis of carcinoma.

  14. Redox potential tuning through differential quinone binding in the photosynthetic reaction center of Rhodobacter sphaeroides.

    Science.gov (United States)

    Vermaas, Josh V; Taguchi, Alexander T; Dikanov, Sergei A; Wraight, Colin A; Tajkhorshid, Emad

    2015-03-31

    Ubiquinone forms an integral part of the electron transport chain in cellular respiration and photosynthesis across a vast number of organisms. Prior experimental results have shown that the photosynthetic reaction center (RC) from Rhodobacter sphaeroides is only fully functional with a limited set of methoxy-bearing quinones, suggesting that specific interactions with this substituent are required to drive electron transport and the formation of quinol. The nature of these interactions has yet to be determined. Through parameterization of a CHARMM-compatible quinone force field and subsequent molecular dynamics simulations of the quinone-bound RC, we have investigated and characterized the interactions of the protein with the quinones in the Q(A) and Q(B) sites using both equilibrium simulation and thermodynamic integration. In particular, we identify a specific interaction between the 2-methoxy group of ubiquinone in the Q(B) site and the amide nitrogen of GlyL225 that we implicate in locking the orientation of the 2-methoxy group, thereby tuning the redox potential difference between the quinones occupying the Q(A) and Q(B) sites. Disruption of this interaction leads to weaker binding in a ubiquinone analogue that lacks a 2-methoxy group, a finding supported by reverse electron transfer electron paramagnetic resonance experiments of the Q(A)⁻Q(B)⁻ biradical and competitive binding assays.

  15. Differential RISC association of endogenous human microRNAs predicts their inhibitory potential.

    Science.gov (United States)

    Flores, Omar; Kennedy, Edward M; Skalsky, Rebecca L; Cullen, Bryan R

    2014-04-01

    It has previously been assumed that the generally high stability of microRNAs (miRNAs) reflects their tight association with Argonaute (Ago) proteins, essential components of the RNA-induced silencing complex (RISC). However, recent data have suggested that the majority of mature miRNAs are not, in fact, Ago associated. Here, we demonstrate that endogenous human miRNAs vary widely, by >100-fold, in their level of RISC association and show that the level of Ago binding is a better indicator of inhibitory potential than is the total level of miRNA expression. While miRNAs of closely similar sequence showed comparable levels of RISC association in the same cell line, these varied between different cell types. Moreover, the level of RISC association could be modulated by overexpression of complementary target mRNAs. Together, these data indicate that the level of RISC association of a given endogenous miRNA is regulated by the available RNA targetome and predicts miRNA function.

  16. Endometrial Cancer Side-Population Cells Show Prominent Migration and Have a Potential to Differentiate into the Mesenchymal Cell Lineage

    Science.gov (United States)

    Kato, Kiyoko; Takao, Tomoka; Kuboyama, Ayumi; Tanaka, Yoshihiro; Ohgami, Tatsuhiro; Yamaguchi, Shinichiro; Adachi, Sawako; Yoneda, Tomoko; Ueoka, Yousuke; Kato, Keiji; Hayashi, Shinichi; Asanoma, Kazuo; Wake, Norio

    2010-01-01

    Cancer stem-like cell subpopulations, referred to as “side-population” (SP) cells, have been identified in several tumors based on their ability to efflux the fluorescent dye Hoechst 33342. Although SP cells have been identified in the normal human endometrium and endometrial cancer, little is known about their characteristics. In this study, we isolated and characterized the SP cells in human endometrial cancer cells and in rat endometrial cells expressing oncogenic human K-Ras protein. These SP cells showed i) reduction in the expression levels of differentiation markers; ii) long-term proliferative capacity of the cell cultures; iii) self-renewal capacity in vitro; iv) enhancement of migration, lamellipodia, and, uropodia formation; and v) enhanced tumorigenicity. In nude mice, SP cells formed large, invasive tumors, which were composed of both tumor cells and stromal-like cells with enriched extracellular matrix. The expression levels of vimentin, α-smooth muscle actin, and collagen III were enhanced in SP tumors compared with the levels in non-SP tumors. In addition, analysis of microdissected samples and fluorescence in situ hybridization of Hec1-SP-tumors showed that the stromal-like cells with enriched extracellular matrix contained human DNA, confirming that the stromal-like cells were derived from the inoculated cells. Moreober, in a Matrigel assay, SP cells differentiated into α-smooth muscle actin-expressing cells. These findings demonstrate that SP cells have cancer stem-like cell features, including the potential to differentiate into the mesenchymal cell lineage. PMID:20008133

  17. Intratumoral heterogeneity: Role of differentiation in a potentially lethal phenotype of testicular cancer.

    Science.gov (United States)

    Tu, Shi-Ming; Bilen, Mehmet Asim; Hess, Kenneth R; Broaddus, Russell R; Kopetz, Scott; Wei, Chongjuan; Pagliaro, Lance C; Karam, Jose A; Ward, John F; Wood, Christopher G; Rao, Priya; Tu, Zachary H; General, Rosale; Chen, Adrienne H; Nieto, Yago L; Yeung, Sai-Ching J; Lin, Sue-Hwa; Logothetis, Christopher J; Pisters, Louis L

    2016-06-15

    Intratumoral heterogeneity presents a major obstacle to the widespread implementation of precision medicine. The authors assessed the origin of intratumoral heterogeneity in nonseminomatous germ cell tumor of the testis (NSGCT) and identified distinct tumor subtypes and a potentially lethal phenotype. In this retrospective study, all consecutive patients who had been diagnosed with an NSGCT between January 2000 and December 2010 were evaluated. The histologic makeup of primary tumors and the clinical course of disease were determined for each patient. A Fine and Gray proportional hazards regression analysis was used to determine the prognostic risk factors, and the Gray test was used to detect differences in the cumulative incidence of cancer death. In a separate prospective study, next-generation sequencing was performed on tumor samples from 9 patients to identify any actionable mutations. Six hundred fifteen patients were included in this study. Multivariate analysis revealed that the presence of yolk sac tumor in the primary tumor (P = .0003) was associated with an unfavorable prognosis. NSGCT could be divided into 5 subgroups. Patients in the yolk sac-seminoma subgroup had the poorest clinical outcome (P = .0015). These tumors tended to undergo somatic transformation (P Cancer 2016;122:1836-43. © 2016 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. © 2016 American Cancer Society.

  18. Use of radiosensitivity to identify irradiated fresh poultry products

    International Nuclear Information System (INIS)

    Copin, M.P.; Bourgeois, C.M.

    1991-01-01

    Microbiological comparison between irradiated and non-irradiated foodstuff has been studied for a long time as a way to detect whether a foodstuff has been irradiated or not. Generally, the proposed methods are based on the fact that ionization select species of bacteria which are recognized to be radioresistant. So reduction or elimination of known radiation sensitive microbes from the normal endogenous microflora could give an indication that the foodstuff has been irradiated, predominance of known radioresistant bacteria should be another indication. In the present work, we try to develop a test based on the radiosensitivity of the bacteria independently of their place. These first experiments show that the determination of radiosensitivity of strains isolated from a product or even of global radioresistance of mesophilic microflora could indicate if this product has been previously submitted to ionizing radiations. (4 tabs)

  19. Rockets, radiosensitizers, and RRx-001: an origin story part I.

    Science.gov (United States)

    Oronsky, Bryan; Scicinski, Jan; Ning, Shoucheng; Peehl, Donna; Oronsky, Arnold; Cabrales, Pedro; Bednarski, Mark; Knox, Susan

    2016-03-01

    From Adam and Eve, to Darwinism, origin stories attempt to fill in the blanks, connect the dots, and define the turning points that are fundamental to subsequent developments. The purpose of this review is to present the origin story of a one-of-a-kind anticancer agent, RRx-001, which emerged from the aerospace industry as a putative radiosensitizer; not since the dynamite-to-dilator transformation of nitroglycerin in 1878 or the post-World War II explosive-to-elixir conversion of hydralazine, an ingredient in rocket fuel, to an antihypertensive, an antidepressant and an antituberculant, has energetic chemistry been harnessed for therapeutic purposes. This is Part 1 of the radiosensitization story; Parts 2 and 3, which detail the crossover activity of RRx-001 as a chemosensitizer in multiple tumor types and disease states including malaria, hemorrhagic shock and sickle cell anemia, are the subject of future reviews.

  20. The dependence of fibroblast radiosensitivity on cell pH

    International Nuclear Information System (INIS)

    Veksler, A.M.; Kublik, L.N.; Degtyareva, O.V.; Ehjdus, L.Kh.

    1983-01-01

    The problem of the change of radiosensitivity of Chinese hamster fibroblasts, irradiated under aerobic and hypoxic conditions in the course of intracellular pH (pHsub(intr.)) change by means of a phosphate buffer has been studied. It has been found that pHsub(intr.) reduction considerably increases the radiosensitivity, the effect being more pronounced on hypoxic cells which is essential for radiotherapy of tumors. The survival rate of cell irradiated under hypoxia conditions does not depend on season while cell resistance in case of irradiation in open air in spring and autumn is different. The effect discovery in case of pHsub(intr.) reduction upon irradiation shows up the influence of the studied factor on repair processes

  1. Glutathione in the modulation of radiosensitivity: a review

    International Nuclear Information System (INIS)

    Umadevi, P.; Prasanna, P.G.S.

    1993-01-01

    Glutathione (γ - glutamyl cysteinyl glycine, GSH) constitutes the major low molecular weight thiol compound in the mammalian cells. GSH has been assigned an important role in determining the inherent radiosensitivity of cells. Endogenous GSH involved in a number of radiation induced chemical processes, which help in the repair of radiation injury to the target molecules. Experimental evidence suggests that GSH competes with molecular oxygen in the cells to prevent fixation of DNA damage. Certain chemicals like buthionine sulfoximine are found to deplete the cellular GSH content by interactions at specific sites in the GSH cycle. It may be possible to take advantage of this phenomenon by increasing the radiosensitivity of hypoxic tumor cells, without seriously affecting the normal cells, so as to increase the therapeutic efficiency of radiation treatment. (author). 52 refs., 1 fig

  2. Dosimetry using radiosensitive gels in radiotherapy: significance and methods

    International Nuclear Information System (INIS)

    Gibon, D.; Bourel, P.; Castelain, B.; Marchandise, X.; Rousseau, J.

    2001-01-01

    The goal of conformal radiotherapy is to concentrate the dose in a well-defined volume by avoiding the neighbouring healthy structures. This technique requires powerful treatment planning software and a rigorous control of estimated dosimetry. The usual dosimetric tools are not adapted to visualize and validate complex 3D treatment. Dosimetry by radiosensitive gel permits visualization and measurement of the three-dimensional dose distribution. The objective of this work is to report on current work in this field and, based on our results and our experience, to draw prospects for an optimal use of this technique. Further developments will relate to the realization of new radiosensitive gels satisfying, as well as possible, cost requirements, easy realization and use, magnetic resonance imagery (MRI) sensitivity, tissue equivalence, and stability. Other developments focus on scanning methods, especially in MRI to measure T1 and T2. (author)

  3. Evaluation of motor neuron differentiation potential of human umbilical cord blood- derived mesenchymal stem cells, in vitro.

    Science.gov (United States)

    Yousefi, Behnam; Sanooghi, Davood; Faghihi, Faezeh; Joghataei, Mohammad Taghi; Latifi, Nourahmad

    2017-04-01

    Many people suffer from spinal cord injuries annually. These deficits usually threaten the quality of life of patients. As a postpartum medically waste product, human Umbilical Cord Blood (UCB) is a rich source of stem cells with self- renewal properties and neural differentiation capacity which made it useful in regenerative medicine. Since there is no report on potential of human umbilical cord blood-derived mesenchymal stem cells into motor neurons, we set out to evaluate the differentiation properties of these cells into motor neuron-like cells through administration of Retinoic Acid(RA), Sonic Hedgehog(Shh) and BDNF using a three- step in vitro procedure. The results were evaluated using Real-time PCR, Flowcytometry and Immunocytochemistry for two weeks. Our data showed that the cells changed into bipolar morphology and could express markers related to motor neuron; including Hb-9, Pax-6, Islet-1, NF-H, ChAT at the level of mRNA and protein. We could also quantitatively evaluate the expression of Islet-1, ChAT and NF-H at 7 and 14days post- induction using flowcytometry. It is concluded that human UCB-MSCs is potent to express motor neuron- related markers in the presence of RA, Shh and BDNF through a three- step protocol; thus it could be a suitable cell candidate for regeneration of motor neurons in spinal cord injuries. Copyright © 2017. Published by Elsevier B.V.

  4. 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

  5. Nicotinamide and carbogen: relationship between pO2 and radiosensitivity in three tumour lines

    International Nuclear Information System (INIS)

    Martin, L.M.; Thomas, C.D.; Guichard, M.

    1994-01-01

    The effects of carbogen breathing, nicotinamide injection and their combination on tumour radiosensitivity were correlated with changes in tumour O 2 tension to determine the relationship between radiosensitivity and measured pO 2 . The radiosensitivity (in vivo-in vitro colony assay) and O 2 tension (computerized pO 2 histograph KIMOC 6650) of two human xenografted tumours (HRT18 and NA11 +) and one murine tumour (EMT6) were measured under similar experimental conditions. (author)

  6. Differentiating TOC sources, preservation, and potential methane emissions in sub-Arctic lakes in Sweden

    Science.gov (United States)

    Johnson, J. E.; Varner, R. K.; Wik, M.; Chanton, J.; Crill, P. M.

    2015-12-01

    derived from this potentially increasing TOC flux, albeit less labile, will not be produced until sometime in the future.

  7. 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)

  8. Cell kinetic and radiosensitivity of PHA stimulated goat lymphocytes

    International Nuclear Information System (INIS)

    Debuyst, B.; Rosenthal, M.; Leonard, A.

    1982-01-01

    The harlequin-staining method has been used to study the cell kinetic of goat peripheral blood lymphocytes stimulated by phytohemagglutinin and to assess their radiosensitivity. At 48 h, the standardized culture time employed for human lymphocytes, 71% of the goat lymphocytes are in first mitosis, 23% are in second mitosis and 5% in third. Irradiation with 200 rads X-rays induces an average of 24,5 dicentric chromosomes per hundred cells in first mitosis [fr

  9. Cell proliferation and radiosensitivity of cow lymphocytes in culture

    International Nuclear Information System (INIS)

    Modave, C.; Fabry, L.; Leonard, A.

    1982-01-01

    The harlequin-staining technique has been used to study, after PHA-stimulation, the cell proliferation of cow lymphocytes in culture and to assess the radiosensitivity in first mitosis cells. At the 48 h fixation time, only 34% of the cells are in first mitosis whereas 55% are already in second and 11% in third mitosis. The exposure of cow lymphocytes to 200 rad X-rays result in the production of 16% dicentric chromosomes in first mitosis cells [fr

  10. Radiosensitivity of yeast cells as a function of radiation LET

    International Nuclear Information System (INIS)

    Lobachevskij, P.N.; Krasavin, E.A.

    1988-01-01

    A model is proposed for interpreting the radiosensitivity of yeast cells as a function of linear energy transfer (LET) of ionizing radiation. The model takes into account the role of repair processes in sensitivity of yeast cells to ionizing radiation of different LET. Two types of repair are discussed: (1) a nonspecific repair (characteristic of both haploid and diploid cells), and (2) a diploid - soecific repair (characteristic of diploid cells only)

  11. Influence of varying diets on radiosensitivity of quinea pigs

    International Nuclear Information System (INIS)

    Darenskaya, N.G.; Kuznetsova, S.S.; Lebengarts, Ya.Z.

    1975-01-01

    Seven groups of 25-day-old Guinea pig males given different diets during the entire observation period. Six groups received full-ration granulated mixed food varying in the contents of protein and cellulose, while the seventh group ate natural food. Experiments with irradiation failed to reveal any essential differences in radiosensitivity of animals grown on natural and mixed food, which enabled us to propose full-ration granulated mixed food for feeding laboratory guinea pigs

  12. Influence of varying diets on radiosensitivity of quinea pigs

    Energy Technology Data Exchange (ETDEWEB)

    Darenskaya, N G; Kuznetsova, S S; Lebengarts, Ya Z

    1975-07-01

    Seven groups of 25-day-old Guinea pig males given different diets during the entire observation period. Six groups received full-ration granulated mixed food varying in the contents of protein and cellulose, while the seventh group ate natural food. Experiments with irradiation failed to reveal any essential differences in radiosensitivity of animals grown on natural and mixed food, which enabled us to propose full-ration granulated mixed food for feeding laboratory guinea pigs.

  13. Days on radiosensitivity: individual variability and predictive tests

    International Nuclear Information System (INIS)

    2008-01-01

    The radiosensitivity is a part of usual clinical observations. It is already included in the therapy protocols. however, some questions stay on its individual variability and on the difficulty to evaluate it. The point will be stocked on its origin and its usefulness in predictive medicine. Through examples on the use of predictive tests and ethical and legal questions that they raise, concrete cases will be presented by specialists such radio biologists, geneticists, immunologists, jurists and occupational physicians. (N.C.)

  14. Comparative study of radiosensitivity of normal and regenerating tissues

    International Nuclear Information System (INIS)

    Samokhvalova, H.S.; Popova, M.F.

    1983-01-01

    A comparative study of radiosensitivity of cells of normal and regenerating tissues of bone marrow and spleen has demonstrated that single exposure to X-rays produces a lesser damaging effect on regenerating tissues than on normal ones. The data obtained indicate that the increase in radioresistance of the organism during active regeneration of the haemopoietic organs is due not merely to the increase in the dividing cell pool of these organs but also to qualitative changes in their functional state

  15. Low-Dose Radiation Cataract and Genetic Determinants of Radiosensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Kleiman, Norman Jay [Columbia University

    2013-11-30

    The lens of the eye is one of the most radiosensitive tissues in the body. Ocular ionizing radiation exposure results in characteristic, dose related, progressive lens changes leading to cataract formation. While initial, early stages of lens opacification may not cause visual disability, the severity of such changes progressively increases with dose until vision is impaired and cataract extraction surgery may be required. Because of the transparency of the eye, radiation induced lens changes can easily be followed non-invasively over time. Thus, the lens provides a unique model system in which to study the effects of low dose ionizing radiation exposure in a complex, highly organized tissue. Despite this observation, considerable uncertainties remain surrounding the relationship between dose and risk of developing radiation cataract. For example, a growing number of human epidemiological findings suggest significant risk among various groups of occupationally and accidentally exposed individuals and confidence intervals that include zero dose. Nevertheless, questions remain concerning the relationship between lens opacities, visual disability, clinical cataract, threshold dose and/or the role of genetics in determining radiosensitivity. Experimentally, the response of the rodent eye to radiation is quite similar to that in humans and thus animal studies are well suited to examine the relationship between radiation exposure, genetic determinants of radiosensitivity and cataractogenesis. The current work has expanded our knowledge of the low-dose effects of X-irradiation or high-LET heavy ion exposure on timing and progression of radiation cataract and has provided new information on the genetic, molecular, biochemical and cell biological features which contribute to this pathology. Furthermore, findings have indicated that single and/or multiple haploinsufficiency for various genes involved in DNA repair and cell cycle checkpoint control, such as Atm, Brca1 or Rad9

  16. The merits of cell kinetic parameters for the assessment of intrinsic cellular radiosensitivity to photon and high linear energy transfer neutron irradiation

    International Nuclear Information System (INIS)

    Theron, Therina; Slabbert, Jacobus; Serafin, Antonio; Boehm, Lothar

    1997-01-01

    Purpose: Differences in tumor response and intrinsic cellular radiosensitivity make the selection of patients for specific radiation modalities very difficult. The reasons for these differences are still unclear, but are thought to be due to genomic and cellular characteristics. Because radiosensitivities vary between cell cycle stages and because S phase cells are very radioresistant, cell cycle kinetic parameters could be a candidate for predicting intrinsic radiosensitivity. Methods and Materials: A panel of 15 tumor cell lines was analyzed for S phase content and potential doubling times (T pot ), and the influence of these parameters on the intrinsic radiosensitivity to 60 Coγ- and p(66)/Be neutron irradiation was assessed. Results: S phase content and T pot show a statistically significant correlation with the mean inactivation dose for photons. The correlation between cell kinetic parameters and the mean inactivation dose for neutrons showed the same trend as photon sensitivity but this was not found to be statistically significant. Conclusions: S phase content and T pot were identified as suitable criteria for predicting photon sensitivity. It is suggested that cell kinetic parameters could play a role in identifying neutron sensitive tumors if both tumor and normal cells are analyzed

  17. 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.

  18. Neural differentiation of lexico-syntactic categories or semantic features? event-related potential evidence for both.

    Science.gov (United States)

    Kellenbach, Marion L; Wijers, Albertus A; Hovius, Marjolijn; Mulder, Juul; Mulder, Gijsbertus

    2002-05-15

    Event-related potentials (ERPs) were used to investigate whether processing differences between nouns and verbs can be accounted for by the differential salience of visual-perceptual and motor attributes in their semantic specifications. Three subclasses of nouns and verbs were selected, which differed in their semantic attribute composition (abstract, high visual, high visual and motor). Single visual word presentation with a recognition memory task was used. While multiple robust and parallel ERP effects were observed for both grammatical class and attribute type, there were no interactions between these. This pattern of effects provides support for lexical-semantic knowledge being organized in a manner that takes account both of category-based (grammatical class) and attribute-based distinctions.

  19. Radiosensitization: enhancing the radiation inactivation of foodborne bacteria

    Science.gov (United States)

    Borsa, J.; Lacroix, M.; Ouattara, B.; Chiasson, F.

    2004-09-01

    Irradiation of meat products to kill pathogens can be limited by radiation-induced detriment of sensory quality. Since such detriment is directly related to dose, one approach to reduce it is by devising means to lower the dose of radiation required for processing. Increasing the radiation sensitivity of the target microorganisms would lower the dose required for a given level of microbial kill. In this work, the radiation sensitivities of inoculated Escherichia coli and Salmonella typhi in ground beef were examined under a variety of conditions. Results showed that specific manipulations of treatment conditions significantly increased the radiation sensitivity of the test organisms, ranging from a few percent to several-fold reduction in D10. In particular, radiation sensitization could be effected by certain additives, including carvacrol, thymol and trans-cinnamaldehyde, and also by certain compositions of modified atmosphere in the package headspace. A combination of additives and modified atmosphere effected a greater radiosensitization effect than could be achieved by either factor applied alone. Radiosensitization could be demonstrated with irradiation of either fresh or frozen ground meat. The radiosensitization phenomenon may be of practical utility in enhancing the technical effectiveness and feasibility of irradiation of a variety of meat and other food products.

  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. Radiosensitization: enhancing the radiation inactivation of foodborne bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Borsa, J. E-mail: jborsa@mds.nordion.com; Lacroix, M.; Ouattara, B.; Chiasson, F

    2004-10-01

    Irradiation of meat products to kill pathogens can be limited by radiation-induced detriment of sensory quality. Since such detriment is directly related to dose, one approach to reduce it is by devising means to lower the dose of radiation required for processing. Increasing the radiation sensitivity of the target microorganisms would lower the dose required for a given level of microbial kill. In this work, the radiation sensitivities of inoculated Escherichia coli and Salmonella typhi in ground beef were examined under a variety of conditions. Results showed that specific manipulations of treatment conditions significantly increased the radiation sensitivity of the test organisms, ranging from a few percent to several-fold reduction in D{sub 10}. In particular, radiation sensitization could be effected by certain additives, including carvacrol, thymol and trans-cinnamaldehyde, and also by certain compositions of modified atmosphere in the package headspace. A combination of additives and modified atmosphere effected a greater radiosensitization effect than could be achieved by either factor applied alone. Radiosensitization could be demonstrated with irradiation of either fresh or frozen ground meat. The radiosensitization phenomenon may be of practical utility in enhancing the technical effectiveness and feasibility of irradiation of a variety of meat and other food products.

  2. Interspecies variations inchromosomal radiosensitivity and repair among mammals

    International Nuclear Information System (INIS)

    Leonard, A.

    1988-01-01

    A review is presented of studies comparing relative chromosomal radiosensitivity of different mammalian species with the objective of assessing the induction of chromosomal aberrations in somatic cells following acute irradiation, the in vivo survival of peripheral blood lymphocytes carrying chromosomal abberations, and the correlation between chromosomal radiosensitivity of peripheral blood lymphocytes and of male germ cells. The ultimate aim was to find whether animal cell experiments can be used to replace experiments in man. The studies showed that the differences in radiosensitivity of the peripheral blood lymphocytes in the most commonly used animals and in man are insignificant and the results in animals are qualitatively and quantitatively representative of what can be expected for man. The life of peripheral blood lymphocytes carrying chromosomal abberations, however, is very short in most experimental animals. The animals thus cannot be used in studies of chromosome damage resulting from chronic irradiation. The studies also show that the yields of dicentric chromosomes in peripheral blood lymphocytes and of reciprocal translocations induced in germ cells are characteristic of each species and animal experiments cannot replace direct studies in man in this respect. (L.O.). 3 tabs., 40 refs

  3. Correlative micro-diffraction and differential phase contrast study of mean inner potential and subtle beam-specimen interaction

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Mingjian, E-mail: mingjian.wu@fau.de; Spiecker, Erdmann, E-mail: erdmann.spiecker@fau.de

    2017-05-15

    Highlights: • Correlative micro-diffraction and DPC-STEM as effective and intuitive method for probing nano-scale electric fields/electrostatic potentials. • Mean inner potential accurately measured by electron refraction from cleaved crystal wedge. • Suggested a pseudo-contactless mode for probing electrostatic potential differences by considering subtle displacements of Fresnel fringes. - Abstract: We present a correlative micro-diffraction and differential phase contrast (DPC) study within scanning transmission electron microscopy (STEM) on the determination of mean inner potential (MIP) and explain the origin of subtle beam-specimen interactions at the edge of wedge-shaped crystals using both experiment and simulation. Our measurement of MIP of Si and GaAs resulted in 12.48 ± 0.22 V and 14.15 ± 0.22 V, respectively, from directly evaluating beam refraction in micro-diffraction mode. DPC-STEM measurements gave very similar values. Fresnel fringes within the diffraction disk resulting from interaction of the highly coherent electron beam with the aperture are observed and a numerical simulation scheme is implemented to reproduce the effect of the specimen on the fringe pattern. Perfect agreement between experiment and simulation has been achieved in terms of subtle displacements of the fringes upon approaching the sample edge with the electron probe. The existence of the fringes has minor effect on the DPC-STEM signal, which is well below the noise level of our setup at practically reasonable acquisition times. We suggest the possibility to perform pseudo-contactless probing of weak potential differences in beam sensitive samples by evaluating the subtle displacements of Fresnel fringes quantitatively.

  4. Migration and differentiation potential of stem cells in the cnidarian Hydractinia analysed in eGFP-transgenic animals and chimeras.

    Science.gov (United States)

    Künzel, Timo; Heiermann, Reinhard; Frank, Uri; Müller, Werner; Tilmann, Wido; Bause, Markus; Nonn, Anja; Helling, Matthias; Schwarz, Ryan S; Plickert, Günter

    2010-12-01

    To analyse cell migration and the differentiation potential of migratory stem cells in Hydractinia, we generated animals with an eGFP reporter gene stably expressed and transmitted via the germline. The transgene was placed under the control of two different actin promoters and the promoter of elongation factor-1α. One actin promoter (Act-II) and the EF-1α promoter enabled expression of the transgene in all cells, the other actin promoter (Act-I) in epithelial and gametogenic cells, but not in the pluripotent migratory stem cells. We produced chimeric animals consisting of histocompatible wild type and transgenic parts. When the transgene was under the control of the epithelial cell specific actin-I promoter, non-fluorescent transgenic stem cells immigrated into wild type tissue, stopped migration and differentiated into epithelial cells which then commenced eGFP-expression. Migratory stem cells are therefore pluripotent and can give rise not only to germ cells, nematocytes and nerve cells, but also to epithelial cells. While in somatic cells expression of the act-I promoter was restricted to epithelial cells it became also active in gametogenesis. The act-I gene is expressed in spermatogonia, oogonia and oocytes. In males the expression pattern showed that migratory stem cells are the precursors of both the spermatogonia and their somatic envelopes. Comparative expression studies using the promoters of the actin-II gene and the elongation factor-1α gene revealed the potential of transgenic techniques to trace the development of the nervous system. Copyright © 2010 Elsevier Inc. All rights reserved.

  5. Embryonic stem cells derived from in vivo or in vitro-generated murine blastocysts display similar transcriptome and differentiation potential.

    Directory of Open Access Journals (Sweden)

    Rhodel K Simbulan

    Full Text Available The use of assisted reproductive technologies (ART such as in vitro fertilization (IVF has resulted in the birth of more than 5 million children. While children conceived by these technologies are generally healthy, there is conflicting evidence suggesting an increase in adult-onset complications like glucose intolerance and high blood pressure in IVF children. Animal models indicate similar potential risks. It remains unclear what molecular mechanisms may be operating during in vitro culture to predispose the embryo to these diseases. One of the limitations faced by investigators is the paucity of the material in the preimplantation embryo to test for molecular analysis. To address this problem, we generated mouse embryonic stem cells (mESC from blastocysts conceived after natural mating (mESCFB or after IVF, using optimal (KSOM + 5% O2; mESCKAA and suboptimal (Whitten's Medium, + 20% O2, mESCWM conditions. All three groups of embryos showed similar behavior during both derivation and differentiation into their respective mESC lines. Unsupervised hierarchical clustering of microarray data showed that blastocyst culture does not affect the transcriptome of derived mESCs. Transcriptomic changes previously observed in the inner cell mass (ICM of embryos derived in the same conditions were not present in mESCs, regardless of method of conception or culture medium, suggesting that mESC do not fully maintain a memory of the events occurring prior to their derivation. We conclude that the fertilization method or culture media used to generate blastocysts does not affect differentiation potential, morphology and transcriptome of mESCs.

  6. 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...

  7. Preservation of differentiation and clonogenic potential of human hematopoietic stem and progenitor cells during lyophilization and ambient storage.

    Science.gov (United States)

    Buchanan, Sandhya S; Pyatt, David W; Carpenter, John F

    2010-09-01

    Progenitor cell therapies show great promise, but their potential for clinical applications requires improved storage and transportation. Desiccated cells stored at ambient temperature would provide economic and practical advantages over approaches employing cell freezing and subzero temperature storage. The objectives of this study were to assess a method for loading the stabilizing sugar, trehalose, into hematopoietic stem and progenitor cells (HPC) and to evaluate the effects of subsequent freeze-drying and storage at ambient temperature on differentiation and clonogenic potential. HPC were isolated from human umbilical cord blood and loaded with trehalose using an endogenous cell surface receptor, termed P2Z. Solution containing trehalose-loaded HPC was placed into vials, which were transferred to a tray freeze-dryer and removed during each step of the freeze-drying process to assess differentiation and clonogenic potential. Control groups for these experiments were freshly isolated HPC. Control cells formed 1450+/-230 CFU-GM, 430+/-140 BFU-E, and 50+/-40 CFU-GEMM per 50 microL. Compared to the values for the control cells, there was no statistical difference observed for cells removed at the end of the freezing step or at the end of primary drying. There was a gradual decrease in the number of CFU-GM and BFU-E for cells removed at different temperatures during secondary drying; however, there were no significant differences in the number of CFU-GEMM. To determine storage stability of lyophilized HPC, cells were stored for 4 weeks at 25 degrees C in the dark. Cells reconstituted immediately after lyophilization produced 580+/-90 CFU-GM ( approximately 40%, relative to unprocessed controls pGM (approximately 35%, relative to unprocessed controls, p<0.0001), 112+/-68 BFU-E (approximately 26%, p<0.0001), and 36+/-17 CFU-GEMM ( approximately 82%, p = 0.2164) These studies are the first to document high level retention of CFU-GEMM following lyophilization and

  8. Preservation of differentiation and clonogenic potential of human hematopoietic stem and progenitor cells during lyophilization and ambient storage.

    Directory of Open Access Journals (Sweden)

    Sandhya S Buchanan

    2010-09-01

    Full Text Available Progenitor cell therapies show great promise, but their potential for clinical applications requires improved storage and transportation. Desiccated cells stored at ambient temperature would provide economic and practical advantages over approaches employing cell freezing and subzero temperature storage. The objectives of this study were to assess a method for loading the stabilizing sugar, trehalose, into hematopoietic stem and progenitor cells (HPC and to evaluate the effects of subsequent freeze-drying and storage at ambient temperature on differentiation and clonogenic potential. HPC were isolated from human umbilical cord blood and loaded with trehalose using an endogenous cell surface receptor, termed P2Z. Solution containing trehalose-loaded HPC was placed into vials, which were transferred to a tray freeze-dryer and removed during each step of the freeze-drying process to assess differentiation and clonogenic potential. Control groups for these experiments were freshly isolated HPC. Control cells formed 1450+/-230 CFU-GM, 430+/-140 BFU-E, and 50+/-40 CFU-GEMM per 50 microL. Compared to the values for the control cells, there was no statistical difference observed for cells removed at the end of the freezing step or at the end of primary drying. There was a gradual decrease in the number of CFU-GM and BFU-E for cells removed at different temperatures during secondary drying; however, there were no significant differences in the number of CFU-GEMM. To determine storage stability of lyophilized HPC, cells were stored for 4 weeks at 25 degrees C in the dark. Cells reconstituted immediately after lyophilization produced 580+/-90 CFU-GM ( approximately 40%, relative to unprocessed controls p<0.0001, 170+/-70 BFU-E (approximately 40%, p<0.0001, and 41+/-22 CFU-GEMM (approximately 82%, p = 0.4171, and cells reconstituted after 28 days at room temperature produced 513+/-170 CFU-GM (approximately 35%, relative to unprocessed controls, p<0

  9. 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

  10. Regional differences in radiosensitivity across the rat cervical spinal cord

    International Nuclear Information System (INIS)

    Bijl, Hendrik P.; Luijk, Peter van; Coppes, Rob P.; Schippers, Jacobus M.; Konings, Antonius W.T.; Kogel, Albert J. van der

    2005-01-01

    Purpose: To study regional differences in radiosensitivity within the rat cervical spinal cord. Methods and materials: Three types of inhomogeneous dose distributions were applied to compare the radiosensitivity of the lateral and central parts of the rat cervical spinal cord. The left lateral half of the spinal cord was irradiated with two grazing proton beams, each with a different penumbra (20-80% isodoses): lateral wide (penumbra = 1.1 mm) and lateral tight (penumbra = 0.8 mm). In the third experiment, the midline of the cord was irradiated with a narrow proton beam with a penumbra of 0.8 mm. The irradiated spinal cord length (CT-2) was 20 mm in all experiments. The animals were irradiated with variable single doses of unmodulated protons (150 MeV) with the shoot-through method, whereby the plateau of the depth-dose profile is used rather than the Bragg peak. The endpoint for estimating isoeffective dose (ED 50 ) values was paralysis of fore and/or hind limbs within 210 days after irradiation. Histology of the spinal cords was performed to assess the radiation-induced tissue damage. Results: High-precision proton irradiation of the lateral or the central part of the spinal cord resulted in a shift of dose-response curves to higher dose values compared with the homogeneously irradiated cervical cord to the same 20-mm length. The ED 50 values were 28.9 Gy and 33.4 Gy for the lateral wide and lateral tight irradiations, respectively, and as high as 71.9 Gy for the central beam experiment, compared with 20.4 Gy for the homogeneously irradiated 20-mm length of cervical cord. Histologic analysis of the spinal cords showed that the paralysis was due to white matter necrosis. The radiosensitivity was inhomogeneously distributed across the spinal cord, with a much more radioresistant central white matter (ED 50 = 71.9 Gy) compared with lateral white matter (ED 50 values = 28.9 Gy and 33.4 Gy). The gray matter did not show any noticeable lesions, such as necrosis or

  11. Biological markers as predictors of radiosensitivity in syngeneic murine tumors

    International Nuclear Information System (INIS)

    Chang, Sei Kyung; Shin, Hyun Soo; Seong, Jin Sil; Kim, Sung Hee

    2006-01-01

    We investigated whether a relationship exists between tumor control dose 50 (TCD 50 ) or tumor growth delay (TGD) and radiation induced apoptosis (RIA) in syngeneic murine tumors. Also we investigated the biological markers that can predict radiosensitivity in murine tumor system through analysis of relationship between TCD 50 , TGD, RIA and constitutive expression levels of the genetic products regulating RIA. Syngeneic murine tumors such as ovarian adenocarcinoma, mammary carcinoma, squamous cell carcinoma, fibrosarcoma, hepatocarcinoma were used in this study. C3H/HeJ mice were bred and maintained in our specific pathogen free mouse colony and were 8 ∼ 12 weeks old when used for the experiments. The tumors, growing in the right hind legs of mice, were analyzed for TCD 50 , TGD, and RIA at 8 mm in diameter. The tumors were also analyzed for the constitutive expression levels of p53, p21 WAF1/CIP1 , BAX, Bcl-2, Bcl-x L , Bcl-x S , and p34. Correlation analysis was performed whether the level of RIA were correlated with TCD 50 or TGD, and the constitutive expression levels of genetic products regulating RIA were correlated with TCD 50 , TGD, RIA. The level of RIA showed a significant positive correlation (R = 0.922, ρ = 0.026) with TGD, and showed a trend to correlation (R = -0.848), marginally significant correlation with TCD 50 (ρ = 0.070). It indicates that tumors that respond to radiation with high percentage of apoptosis were more radiosensitive. The constitutive expression levels of p21 WAF1/CIP1 and p34 showed a significant correlation either with TCD 50 (R = 0.893, ρ = 0.041 and R = 0.904, ρ = 0.035) or with TGD (R = -0.922, ρ 0.026 and R = -0.890, ρ = 0.043). The tumors with high constitutive expression levels of p21 WAF1/CIP1 or p34 were less radiosensitive than those with low expression. Radiosensitivity may be predicted with the level of RIA in murine tumors. The constitutive expression levels of p21 WAF1/CIP1 or p34 can be used as biological

  12. 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

  13. Biological markers as predictors of radiosensitivity in syngeneic murine tumors

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Sei Kyung; Shin, Hyun Soo [Bundang CHA General Hospital, Seongnam (Korea, Republic of); Seong, Jin Sil; Kim, Sung Hee [Yonsei Cancer Center, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2006-06-15

    We investigated whether a relationship exists between tumor control dose 50 (TCD{sub 50}) or tumor growth delay (TGD) and radiation induced apoptosis (RIA) in syngeneic murine tumors. Also we investigated the biological markers that can predict radiosensitivity in murine tumor system through analysis of relationship between TCD{sub 50}, TGD, RIA and constitutive expression levels of the genetic products regulating RIA. Syngeneic murine tumors such as ovarian adenocarcinoma, mammary carcinoma, squamous cell carcinoma, fibrosarcoma, hepatocarcinoma were used in this study. C3H/HeJ mice were bred and maintained in our specific pathogen free mouse colony and were 8 {approx} 12 weeks old when used for the experiments. The tumors, growing in the right hind legs of mice, were analyzed for TCD{sub 50}, TGD, and RIA at 8 mm in diameter. The tumors were also analyzed for the constitutive expression levels of p53, p21{sup WAF1/CIP1}, BAX, Bcl-2, Bcl-x{sub L}, Bcl-x{sub S}, and p34. Correlation analysis was performed whether the level of RIA were correlated with TCD{sub 50} or TGD, and the constitutive expression levels of genetic products regulating RIA were correlated with TCD{sub 50}, TGD, RIA. The level of RIA showed a significant positive correlation (R = 0.922, {rho} = 0.026) with TGD, and showed a trend to correlation (R = -0.848), marginally significant correlation with TCD{sub 50} ({rho} = 0.070). It indicates that tumors that respond to radiation with high percentage of apoptosis were more radiosensitive. The constitutive expression levels of p21{sup WAF1/CIP1} and p34 showed a significant correlation either with TCD{sub 50} (R = 0.893, {rho} = 0.041 and R = 0.904, {rho} = 0.035) or with TGD (R = -0.922, {rho} 0.026 and R = -0.890, {rho} = 0.043). The tumors with high constitutive expression levels of p21{sup WAF1/CIP1} or p34 were less radiosensitive than those with low expression. Radiosensitivity may be predicted with the level of RIA in murine tumors. The

  14. On the classical theory of ordinary linear differential equations of the second order and the Schroedinger equation for power law potentials

    International Nuclear Information System (INIS)

    Lima, M.L.; Mignaco, J.A.

    1983-01-01

    The power law potentials in the Schroedinger equation solved recently are shown to come from the classical treatment of the singularities of a linear, second order differential equation. This allows to enlarge the class of solvable power law potentials. (Author) [pt

  15. Labeling Adipose-Derived Stem Cells with Hoechst 33342: Usability and Effects on Differentiation Potential and DNA Damage

    Directory of Open Access Journals (Sweden)

    P. Schendzielorz

    2016-01-01

    Full Text Available Adipose-derived stem cells (ASCs have been extensively studied in the field of stem cell research and possess numerous clinical applications. Cell labeling is an essential component of various experimental protocols and Hoechst 33342 (H33342 represents a cost-effective and easy methodology for live staining. The purpose of this study was to evaluate the labeling of rat ASCs with two different concentrations of H33342 (0.5 μg/mL and 5 μg/mL, with particular regard to usability, interference with cell properties, and potential DNA damage. Hoechst 33342 used at a low concentration of 0.5 μg/mL did not significantly affect cell proliferation, viability, or differentiation potential of the ASCs, nor did it cause any significant DNA damage as measured by the olive tail moment. High concentrations of 5 μg/mL H33342, however, impaired the proliferation and viability of the ASCs, and considerable DNA damage was observed. Undesirable colabeling of unlabeled cocultivated cells was seen in particular with higher concentrations of H33342, independent of varying washing procedures. Hence, H33342 labeling with lower concentrations represents a usable method, which does not affect the tested cell properties. However, the colabeling of adjacent cells is a drawback of the technique.

  16. Resveratrol-Induced Apoptosis and Increased Radiosensitivity in CD133-Positive Cells Derived From Atypical Teratoid/Rhabdoid Tumor

    International Nuclear Information System (INIS)

    Kao, C.-L.; Huang, P.-I; Tsai, P.-H.; Tsai, M.-L.; Lo, J.-F.; Lee, Y.-Y.; Chen, Y.-J.; Chen, Y.-W.; Chiou, S.-H.

    2009-01-01

    Purpose: CD133 has recently been proposed as a marker for cancer stem-like cells (CSC) in brain tumors. The aim of the present study was to investigate the possible role of resveratrol (RV) in radiosensitivity of CD133-positive/-negative cells derived from atypical teratoid/rhabdoid tumors (AT/RT-CD133 +/- ). Materials and Methods: AT/RT-CD133 +/- were isolated and characterized by flow cytometry and quantitative real-time reverse transcription-polymerase chain reaction, and then treated with RV at different doses. Migratory ability, colony formation, apoptotic activity, and xenotransplantation were assessed for RV alone, ionizing radiation (IR) alone, and IR with RV conditions. Results: AT/RT-CD133 + displayed enhanced self-renewal and highly coexpressed 'stem cell' genes and drug-resistant genes, in addition to showing significant resistance to chemotherapeutic agents and radiotherapy as compared with CD133 - cells. After treatment with 200 μM RV, the in vitro proliferation rates and in vivo tumor restoration abilities of ATRT-CD133 + were dramatically inhibited. Importantly, treatment with 150 μM RV can effectively inhibit the expression of drug-resistant genes in AT/RT-CD133 + , and further facilitate to the differentiation of CD133 + into CD133 - . In addition, treatment with 150 μM RV could significantly enhance the radiosensitivity and IR-mediated apoptosis in RV-treated ATRT-CD133 +/- . Kaplan-Meier survival analysis indicated that the mean survival rate of mice with ATRT-CD133 + that were treated with IR could be significantly improved when IR was combined with 150 μM RV treatment. Conclusions: AT/RT-CD133 + exhibit CSC properties and are refractory to IR treatment. Our results suggest that RV treatment plays crucial roles in antiproliferative, proapoptotic, and radiosensitizing effects on treated-CD133 +/- ; RV may therefore improve the clinical treatment of AT/RT.

  17. Impact of maternal diabetes type 1 on proliferative potential, differentiation and apoptotic activity in villous capillaries of term placenta.

    Science.gov (United States)

    Jirkovská, Marie; Kučera, Tomáš; Dvořáková, Veronika; Jadrníček, Martin; Moravcová, Milena; Žižka, Zdeněk; Krejčí, Vratislav

    2016-04-01

    Maternal diabetes mellitus changes morphology and impairs function of placental capillaries. Here, quantitative parameters characterizing cell proliferation using detection of Ki67, differentiation reflected by nestin expression and apoptosis in placental capillary bed with active caspase 3 as a marker were compared in normal term placentas and placentas from pregnancies complicated by Type 1 maternal diabetes mellitus. Specimens of sixteen diabetic placentas and eight control placentas were collected by systematic uniform random sampling. Immunohistochemical detections of Ki67, nestin, and active caspase 3 were performed in histological sections of five haphazardly chosen blocks per placenta. Twenty fields of view per section, i.e. one hundred fields of view per placenta, were used for analysis of proliferation as well as of apoptosis, and in approximately 70 capillary cross-sections per placenta the nestin-positive segments of their circumference were measured. The percentage of Ki67-positive cells counted in the capillary wall was significantly lower in diabetic group. The counts of Ki67-labelled nuclei per villous area unit were significantly lower in cytotrophoblast and capillary wall of terminal villi in diabetic placenta. The proportion of nestin-labeled segments of capillary circumference was significantly higher in placentas of diabetic group. No differences in the numbers of apoptotic cells were found between studied groups. The results show that the term placenta in Type 1 diabetes has lower potential to enlarge the surface area of structures involved in maternofetal transport, and that the villous capillary bed displays delayed differentiation. Those factors may participate in decreased ability of diabetic placenta to comply with fetal requirements in the final stage of pregnancy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Differentially expressed plasma microRNAs and the potential regulatory function of Let-7b in chronic thromboembolic pulmonary hypertension.

    Directory of Open Access Journals (Sweden)

    Lijuan Guo

    Full Text Available Chronic thromboembolic pulmonary hypertension (CTEPH is a progressive disease characterized by misguided thrombolysis and remodeling of pulmonary arteries. MicroRNAs are small non-coding RNAs involved in multiple cell processes and functions. During CTEPH, circulating microRNA profile endued with characteristics of diseased cells could be identified as a biomarker, and might help in recognition of pathogenesis. Thus, in this study, we compared the differentially expressed microRNAs in plasma of CTEPH patients and healthy controls and investigated their potential functions. Microarray was used to identify microRNA expression profile and qRT-PCR for validation. The targets of differentially expressed microRNAs were identified in silico, and the Gene Ontology database and Kyoto Encyclopedia of Genes and Genomes pathway database were used for functional investigation of target gene profile. Targets of let-7b were validated by fluorescence reporter assay. Protein expression of target genes was determined by ELISA or western blotting. Cell migration was evaluated by wound healing assay. The results showed that 1 thirty five microRNAs were differentially expressed in CTEPH patients, among which, a signature of 17 microRNAs, which was shown to be related to the disease pathogenesis by in silico analysis, gave diagnostic efficacy of both sensitivity and specificity >0.9. 2 Let-7b, one of the down-regulated anti-oncogenic microRNAs in the signature, was validated to decrease to about 0.25 fold in CTEPH patients. 3 ET-1 and TGFBR1 were direct targets of let-7b. Altering let-7b level influenced ET-1 and TGFBR1 expression in pulmonary arterial endothelial cells (PAECs as well as the migration of PAECs and pulmonary arterial smooth muscle cells (PASMCs. These results suggested that CTEPH patients had aberrant microRNA signature which might provide some clue for pathogenesis study and biomarker screening. Reduced let-7b might be involved in the pathogenesis of

  19. Differentially Expressed Plasma MicroRNAs and the Potential Regulatory Function of Let-7b in Chronic Thromboembolic Pulmonary Hypertension

    Science.gov (United States)

    Guo, Lijuan; Yang, Yuanhua; Liu, Jie; Wang, Lei; Li, Jifeng; Wang, Ying; Liu, Yan; Gu, Song; Gan, Huili; Cai, Jun; Yuan, Jason X.-J.; Wang, Jun; Wang, Chen

    2014-01-01

    Chronic thromboembolic pulmonary hypertension (CTEPH) is a progressive disease characterized by misguided thrombolysis and remodeling of pulmonary arteries. MicroRNAs are small non-coding RNAs involved in multiple cell processes and functions. During CTEPH, circulating microRNA profile endued with characteristics of diseased cells could be identified as a biomarker, and might help in recognition of pathogenesis. Thus, in this study, we compared the differentially expressed microRNAs in plasma of CTEPH patients and healthy controls and investigated their potential functions. Microarray was used to identify microRNA expression profile and qRT-PCR for validation. The targets of differentially expressed microRNAs were identified in silico, and the Gene Ontology database and Kyoto Encyclopedia of Genes and Genomes pathway database were used for functional investigation of target gene profile. Targets of let-7b were validated by fluorescence reporter assay. Protein expression of target genes was determined by ELISA or western blotting. Cell migration was evaluated by wound healing assay. The results showed that 1) thirty five microRNAs were differentially expressed in CTEPH patients, among which, a signature of 17 microRNAs, which was shown to be related to the disease pathogenesis by in silico analysis, gave diagnostic efficacy of both sensitivity and specificity >0.9. 2) Let-7b, one of the down-regulated anti-oncogenic microRNAs in the signature, was validated to decrease to about 0.25 fold in CTEPH patients. 3) ET-1 and TGFBR1 were direct targets of let-7b. Altering let-7b level influenced ET-1 and TGFBR1 expression in pulmonary arterial endothelial cells (PAECs) as well as the migration of PAECs and pulmonary arterial smooth muscle cells (PASMCs). These results suggested that CTEPH patients had aberrant microRNA signature which might provide some clue for pathogenesis study and biomarker screening. Reduced let-7b might be involved in the pathogenesis of CTEPH by

  20. Investigating population differentiation in a major African agricultural pest: evidence from geometric morphometrics and connectivity suggests high invasion potential.

    Science.gov (United States)

    Karsten, M; Addison, P; Jansen van Vuuren, B; Terblanche, J S

    2016-07-01

    The distribution, spatial pattern and population dynamics of a species can be influenced by differences in the environment across its range. Spatial variation in climatic conditions can cause local populations to undergo disruptive selection and ultimately result in local adaptation. However, local adaptation can be constrained by gene flow and may favour resident individuals over migrants-both are factors critical to the assessment of invasion potential. The Natal fruit fly (Ceratitis rosa) is a major agricultural pest in Africa with a history of island invasions, although its range is largely restricted to south east Africa. Across Africa, C. rosa is genetically structured into two clusters (R1 and R2), with these clusters occurring sympatrically in the north of South Africa. The spatial distribution of these genotypic clusters remains unexamined despite their importance for understanding the pest's invasion potential. Here, C. rosa, sampled from 22 South African locations, were genotyped at 11 polymorphic microsatellite loci and assessed morphologically using geometric morphometric wing shape analyses to investigate patterns of population structure and determine connectedness of pest-occupied sites. Our results show little to no intraspecific (population) differentiation, high population connectivity, high effective population sizes and only one morphological type (R2) within South Africa. The absence of the R1 morphotype at sites where it was previously found may be a consequence of differences in thermal niches of the two morphotypes. Overall, our results suggest high invasion potential of this species, that area-wide pest management should be undertaken on a country-wide scale, and that border control is critical to preventing further invasions. © 2016 John Wiley & Sons Ltd.

  1. Increased radiosensitivity and radiation-induced apoptosis in SRC-3 knockout mice

    International Nuclear Information System (INIS)

    Jin Jie; Wang Yu; Xu Yang; Chen Shilei; Wang Junping; Ran Xinze; Su Yongping; Wang Jin

    2014-01-01

    Steroid receptor coactivator-3 (SRC-3), a multifunctional transcriptional coactivator, plays an important role in regulation of cell apoptosis in chemoresistant cancer cells. However, its role in radiation-induced apoptosis in hematopoietic cells is still unclear. In this study, we used SRC-3 knockout (SRC-3 -/- ) mice to assess the role of SRC-3 in radiation-induced hematopoietic injury in vivo. After a range of doses of irradiation, SRC-3 -/- mice exhibited lower counts of peripheral blood cells and bone marrow (BM) mononuclear cells and excessive BM depression, which resulted in a significantly higher mortality compared with wildtype mice. Moreover, BM mononuclear cells obtained from SRC-3 -/- mice showed a remarkable increase in radiation-induced apoptosis. Collectively, our data demonstrate that SRC-3 plays a role in radiation-induced apoptosis of BM hematopoietic cells. Regulation of SRC-3 might influence the radiosensitivity of hematopoietic cells, which highlights a potential therapeutic target for radiation-induced hematopoietic injury. (author)

  2. Modification of the radiosensitivity of barley seed by post-treatment with caffeine

    International Nuclear Information System (INIS)

    Kesavan, P.C.; Ahmad, A.

    1976-01-01

    Barley seeds of a hull-less variety (IB 65) were γ-irradiated (40 and 45 krad, 100 rad/sec) at 25 0 C, and the seeds were post-hydrated for 12 hours at approximately 3 0 C in oxygenated and oxygen-free water or caffeine solutions (3.8 x 10 -4 to 3.8 x 10 -2 M). Measurements of 8-day seedling growth showed that the different caffeine concentrations applied during oxygenated or oxygen-free hydrations produced no observable effects on the growth of unirradiated seeds. All caffeine concentrations afforded protection for the irradiated seeds under oxygenated conditions, and potentiated the damage under oxygen-free conditions. A maximum radio-protection occurred at a caffeine concentration of 3.8 x 10 -3 M, whereas radiosensitization under oxygen-free conditions was concentration-dependent. Possible mechanisms are discussed. (U.K.)

  3. Mechanism of anticarcinogenic properties of curcumin and its application for radio-sensitization and clinical treatment

    International Nuclear Information System (INIS)

    Enomoto, Atsushi; Miyagawa, Kiyoshi; Yamada, Junko

    2016-01-01

    Curcumin is a yellow-colored polyphenol and a major component of turmeric (Curcuma longa). It is also an active ingredient in the herbal remedy and dietary spice. Curcumin has a long history of administration in traditional medicine of China. Extensive investigations on pharmacological activity of curcumin have demonstrated that curcumin possesses anti-carcinogenic, anti-inflammatory, and anti-oxidant properties. Curcumin, a kind of phytochemical, due to its beneficial pharmacological effects and an excellent safety profile, is demonstrated to be a potential candidate for the prevention and/or treatment of a variety of diseases. In this review, we introduce pharmacological action and molecular targets of curcumin, and describe its application for radio-sensitization and clinical treatment. (author)

  4. The Schroedinger equation for central power law potentials and the classical theory of ordinary linear differential equations of the second order

    International Nuclear Information System (INIS)

    Lima, M.L.; Mignaco, J.A.

    1985-01-01

    It is shown that the rational power law potentials in the two-body radial Schrodinger equations admit a systematic treatment available from the classical theory of ordinary linear differential equations of the second order. The resulting potentials come into families evolved from equations having a fixed number of elementary regular singularities. As a consequence, relations are found and discussed among the several potentials in a family. (Author) [pt

  5. The Schroedinger equation for central power law potentials and the classical theory of ordinary linear differential equations of the second order

    International Nuclear Information System (INIS)

    Lima, M.L.; Mignaco, J.A.

    1985-01-01

    It is shown that the rational power law potentials in the two-body radial Schoedinger equation admit a systematic treatment available from the classical theory of ordinary linear differential equations of the second order. The admissible potentials come into families evolved from equations having a fixed number of elementary singularities. As a consequence, relations are found and discussed among the several potentials in a family. (Author) [pt

  6. Label-free morphology-based prediction of multiple differentiation potentials of human mesenchymal stem cells for early evaluation of intact cells.

    Directory of Open Access Journals (Sweden)

    Hiroto Sasaki

    Full Text Available Precise quantification of cellular potential of stem cells, such as human bone marrow-derived mesenchymal stem cells (hBMSCs, is important for achieving stable and effective outcomes in clinical stem cell therapy. Here, we report a method for image-based prediction of the multiple differentiation potentials of hBMSCs. This method has four major advantages: (1 the cells used for potential prediction are fully intact, and therefore directly usable for clinical applications; (2 predictions of potentials are generated before differentiation cultures are initiated; (3 prediction of multiple potentials can be provided simultaneously for each sample; and (4 predictions of potentials yield quantitative values that correlate strongly with the experimental data. Our results show that the collapse of hBMSC differentiation potentials, triggered by in vitro expansion, can be quantitatively predicted far in advance by predicting multiple potentials, multi-lineage differentiation potentials (osteogenic, adipogenic, and chondrogenic and population doubling potential using morphological features apparent during the first 4 days of expansion culture. In order to understand how such morphological features can be effective for advance predictions, we measured gene-expression profiles of the same early undifferentiated cells. Both senescence-related genes (p16 and p21 and cytoskeleton-related genes (PTK2, CD146, and CD49 already correlated to the decrease of potentials at this stage. To objectively compare the performance of morphology and gene expression for such early prediction, we tested a range of models using various combinations of features. Such comparison of predictive performances revealed that morphological features performed better overall than gene-expression profiles, balancing the predictive accuracy with the effort required for model construction. This benchmark list of various prediction models not only identifies the best morphological feature

  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. A study on the toxicity of three radiosensitizers on retinoblastoma cells by MTT assay

    International Nuclear Information System (INIS)

    Yi Xianjin; Jin Yizun; Ding Li; Ni Zhou; Wang Wenji

    1994-01-01

    The toxicity of three radiosensitizers BSO, CM and RSU-1069 on retinoblastoma cells was determined and the efficiency of in vitro MTT assay on drug-screening for retinoblastoma was also evaluated. The results showed that the MTT assay is very useful. The toxicity of radiosensitizers on retinoblastoma cells is dependent on cell line characteristics, drug concentration and time of exposure to it

  9. 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.)

  10. THERMAL RADIOSENSITIZATION IN HEAT-SENSITIVE AND RADIATION-SENSITIVE MUTANTS OF CHO CELLS

    NARCIS (Netherlands)

    KAMPINGA, HH; KANON, B; KONINGS, AWT; STACKHOUSE, MA; BEDFORD, JS

    Recently, it has been hypothesized (Iliakis and Seaner 1990) that DNA double-strand break (dsb) repair proficiency is a prerequisite for heat radiosensitization on the basis of the finding that the radiosensitive and dsb-repair-deficient mutant xrs-5 cell line shows no significant heat-induced

  11. Chromatin structure and cellular radiosensitivity : A comparison of two human tumour cell lines

    NARCIS (Netherlands)

    Woudstra, EC; Roesink, JM; Rosemann, M; Brunsting, JF; Driessen, C; Orta, T; Konings, AWT; Peacock, JH; Kampinga, HH

    1996-01-01

    The role of variation in susceptibility to DNA damage induction was studied as a determinant for cellular radiosensitivity. Comparison of the radiosensitive HX142 and radioresistant RT112 cell lines previously revealed higher susceptibility to X-ray-induced DNA damage in the sensitive cell line

  12. Increased betulinic acid induced cytotoxicity and radiosensitivity in glioma cells under hypoxic conditions

    International Nuclear Information System (INIS)

    Bache, Matthias; Taubert, Helge; Vordermark, Dirk; Zschornak, Martin P; Passin, Sarina; Keßler, Jacqueline; Wichmann, Henri; Kappler, Matthias; Paschke, Reinhard; Kaluđerović, Goran N; Kommera, Harish

    2011-01-01

    of improving the effects of tumor therapy in human malignant glioma cells, particularly under hypoxic conditions. Further investigations are necessary to characterize its potential as a radiosensitizer

  13. Autotaxin inhibition with PF8380 enhances the radiosensitivity of human and murine glioblastoma cell lines

    Directory of Open Access Journals (Sweden)

    Sandeep R Bhave

    2013-09-01

    Full Text Available Purpose: Glioblastoma multiforme (GBM is an aggressive primary brain tumor tha