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Sample records for cell specific radiation

  1. Hypoxia- and radiation-inducible, breast cell-specific targeting of retroviral vectors

    International Nuclear Information System (INIS)

    To facilitate a more efficient radiation and chemotherapy of mammary tumours, synthetic enhancer elements responsive to hypoxia and ionizing radiation were coupled to the mammary-specific minimal promoter of the murine whey acidic protein (WAP) encoding gene. The modified WAP promoter was introduced into a retroviral promoter conversion (ProCon) vector. Expression of a transduced reporter gene in response to hypoxia and radiation was analysed in stably infected mammary cancer cell lines and an up to 9-fold increase in gene expression demonstrated in comparison to the respective basic vector. Expression analyses in vitro, moreover, demonstrated a widely preserved mammary cell-specific promoter activity. For in vivo analyses, xenograft tumours consisting of infected human mammary adenocarcinoma cells were established in SCID/beige mice. Immunohistochemical analyses demonstrated a hypoxia-specific, markedly increased WAP promoter-driven expression in these tumours. Thus, this retroviral vector will facilitate a targeted gene therapeutic approach exploiting the unique environmental condition in solid tumours

  2. Role of lymphocyte-specific protein tyrosine kinase (LCK) in the expansion of glioma-initiating cells by fractionated radiation

    International Nuclear Information System (INIS)

    Research highlights: → Activation of Lymphocyte-specific protein tyrosine kinase (LCK) is involved in the fractionated radiation-induced expansion of glioma stem-like cells. → Inhibition of LCK prevents acquisition of fractionated radiation-induced resistance to chemotherapeutic treatment. → LCK activity is critical for the maintenance of self-renewal in glioma stem-like cells. -- Abstract: Brain cancers frequently recur or progress as focal masses after treatment with ionizing radiation. Radiation used to target gliomas may expand the cancer stem cell population and enhance the aggressiveness of tumors; however, the mechanisms underlying the expansion of cancer stem cell population after radiation have remained unclear. In this study, we show that LCK (lymphocyte-specific protein tyrosine kinase) is involved in the fractionated radiation-induced expansion of the glioma-initiating cell population and acquisition of resistance to anticancer treatments. Fractionated radiation caused a selective increase in the activity of LCK, a Src family non-receptor tyrosine kinase. The activities of other Src family kinases Src, Fyn, and Lyn were not significantly increased. Moreover, knockdown of LCK expression with a specific small interfering RNA (siRNA) effectively blocked fractionated radiation-induced expansion of the CD133+ cell population. siRNA targeting of LCK also suppressed fractionated radiation-induced expression of the glioma stem cell marker proteins CD133, Nestin, and Musashi. Expression of the known self-renewal-related proteins Notch2 and Sox2 in glioma cells treated with fractionated radiation was also downregulated by LCK inhibition. Moreover, siRNA-mediated knockdown of LCK effectively restored the sensitivity of glioma cells to cisplatin and etoposide. These results indicate that the non-receptor tyrosine kinase LCK is critically involved in fractionated radiation-induced expansion of the glioma-initiating cell population and decreased cellular

  3. Production of antigen-specific suppressive T cell factor by radiation leukemia virus-transformed suppressor T cells

    International Nuclear Information System (INIS)

    Hen egg-white lysozyme-specific suppressor T cells induced in C57BL/6 mice have been selected by sequential passage over plates coated with goat anti-mouse Ig and HEL. These suppressor T cells, 80% I-J+, were infected in vitro with radiation leukemia virus and injected intravenously into sublethally irradiated syngeneic recipients. After 4 to 6 months, 6 out of 20 injected mice developed thymic lymphomas, which were maintained by transplantation into histocompatible hosts and subsequently established as permanent cell lines. Cells of these six thymomas were screened for the presence of Thy 1.2, Lyt 1, Lyt 2, I-J/sup b/, and Ig cell surface antigens by direct or indirect immunofluorescence. One tumor was found to express the expected phenotype of suppressor T cells. High-speed supernatants of extracts obtained from L4 cells were able to induce HEL-specific suppression in a T cell proliferative assay, demonstrating the presence of an antigen-specific suppressive T cell factor

  4. Production of antigen-specific suppressive T cell factor by radiation leukemia virus-transformed suppressor T cells.

    OpenAIRE

    Ricciardi-Castagnoli, P; Doria, G; Adorini, L

    1981-01-01

    Hen egg-white lysozyme (HEL)-specific suppressor T cells induced in C57BL/6 mice have been selected by sequential passage over plates coated with goat anti-mouse Ig and HEL. These suppressor T cells, 80% I-J+, were infected in vitro with radiation leukemia virus (RadLV/Nu1) and injected intravenously into sublethally irradiated syngeneic recipients. After 4-6 months, 6 out of 20 injected mice developed thymic lymphomas, which were maintained by transplantation into histocompatible hosts and s...

  5. Immunoregulatory adherent cells in human tuberculosis: radiation-sensitive antigen-specific suppression by monocytes

    Energy Technology Data Exchange (ETDEWEB)

    Kleinhenz, M.E.; Ellner, J.J.

    1985-07-01

    In human tuberculosis, adherent mononuclear cells (AMC) selectively depress in vitro responses to the mycobacterial antigen tuberculin purified protein derivative (PPD). The phenotype of this antigen-specific adherent suppressor cell was characterized by examining the functional activity of adherent cells after selective depletion of sheep erythrocyte-rosetting T cells or OKM1-reactive monocytes. Adherent cell suppression was studied in the (/sup 3/H)thymidine-incorporation microculture assay by using T cells rigorously depleted of T cells with surface receptors for the Fc portion of IgG (T gamma cells) as antigen-responsive cells. PPD-induced (/sup 3/H)thymidine incorporation by these non gamma T cells was uniformly reduced (mean, 42% +/- 10% (SD)) when autologous AMC were added to non gamma T cells at a ratio of 1:2. Antigen-specific suppression by AMC was not altered by depletion of sheep erythrocyte-rosetting T cells or treatment with indomethacin. However, AMC treated with OKM1 and complement or gamma irradiation (1,500 rads) no longer suppressed tuberculin responses in vitro. These studies identify the antigen-specific adherent suppressor cell in tuberculosis as an OKM1-reactive, non-erythrocyte-rosetting monocyte. The radiosensitivity of this monocyte immunoregulatory function may facilitate its further definition.

  6. Single cell and tissue specific methods for evaluation of radiation and microgravity effects

    Energy Technology Data Exchange (ETDEWEB)

    Van Oostveldt, P.; Vangestel, S. [Laboratory for Biochemistry and Molecular Cytology, Coupure Links 653, B-9000 Gent (Belgium); Meesen, G.; Poffyen, A. [Institute for Nuclear Science, University Gent, Proeftuinstraat 86, B-9000 Gent (Belgium); Coene, E.D.; Schelfhout, V.R.J.; De Potter, C.R. [N Goormaghtigh Institute for Pathology, University Hospital, De Pintelaan 185, B-9000 Gent (Belgium)

    1999-12-06

    A discussion of different methods to evaluate dose/response and biological effects of ionizing radiation is given. Confocal scanning laser microscopy (CSLM) is presented as a high performing observation method for evaluating different cytological effects. Standard cytochemical techniques can be used to analyse the cell in situ with minimal disturbance of morphology and structure. If a relatively small number of cells are affected by the treatment, the use of confocal microscope observations is fast and has a better resolution than conventional fluorescence microscopy. The optical sectioning capability of the CSLM makes it possible to analyse stacks of cells on detectors up to a depth of 200 {mu}m with a resolution of 0.7 {mu}m. This is used to analyse single cell electrophoresis results and nuclear track analysis in poly allyl diglycol carbonate (PADC). Consecutive analysis of cells cultivated on PADC, and analysis of nuclear tracks after chemical etched tracks in the PADC, will make it possible to correlate physical dose with direct cellular effects. This is a promising method for single cell analysis and the study of the effects of ionizing radiation at low particle flux density.

  7. Observation of radiation-specific damage in human cells exposed to depleted uranium: dicentric frequency and neoplastic transformation as endpoints

    International Nuclear Information System (INIS)

    Depleted uranium (DU) is a dense heavy metal used primarily in military applications. Published data from our laboratory have demonstrated that DU exposure in vitro to immortalised human osteoblast cells (HOS) is both neoplastically transforming and genotoxic. DU possesses both a radiological (alpha-particle) and chemical (metal) component. Since DU has a low specific activity in comparison to natural uranium, it is not considered to be a significant radiological hazard. The potential contribution of radiation to DU-induced biological effects is unknown and the involvement of radiation in DU-induced biological effects could have significant implication for current risk estimates for internalised DU exposure. Two approaches were used to address this question. The frequency of dicentrics was measured in HOS cells following DU exposure in vitro. Data demonstrated that DU exposure (50 μM, 24h) induced a significant elevation in dicentric frequency in vitro in contrast to incubation with the heavy metals, nickel and tungsten which did not increase dicentric frequency above background levels. Using the same concentration (50 μM) of three uranyl nitrate compounds that have different uranium isotopic concentrations and therefore, different specific activities, the effect on neoplastic transformation in vitro was examined. HOS cells were exposed to one of three-uranyl nitrate compounds (238U-uranyl nitrate, specific activity 0.33 μCi.g-1: DU-uranyl nitrate, specific activity 0.44 μCi.g-1: and 235U-uranyl nitrate, specific activity 2.2 μCi.g-1) delivered at a concentration of 50 μM for 24 h. Results showed, at equal uranium concentration, there was a specific activity dependent increase in neoplastic transformation frequency. Taken together these data suggest that radiation can play a role in DU-induced biological effects in vitro. (author)

  8. Comparison of the effectiveness of different radiations for the induction of reproductive death, chromosome aberrations, morphological transformations and specific mutations in cultured mammalian cells

    International Nuclear Information System (INIS)

    Ionizing radiations can induce a variety of changes in cultured mammalian cells, many of which are initiated by damage to the chromosomes. If the primary mechanisms of damage at the molecular level are similar, it can be expected that dose-effect relationships for the different cellular responses should exhibit common characteristics. A comparison of dose-effect relationships has been made for published data on several types of cells treated with radiations of different Linear Energy Transfer (LET) and assessed with respect to two or more endpoints. Various types of cells have different sensitivities to low LET as well as to high LET radiation and cellular effects are induced at different frequencies per unit dose. Cell reproductive death and chromosome aberrations can presumably be induced as a result of damage in any one of the chromosomes. Chromosome breaks leading to deletions may occur at many sites. The probability of breaks may not be uniform along chromosomes, but this is difficult to establish. Cell transformation is more frequently (30 to 1000 times) induced by ionizing radiations than specific gene mutations and it may therefore be inferred that many, if not all, chromosomes contain one or more sites with genes which, if damaged, deleted or transposed to another site, may cause morphological malignant transformation. (Auth./C.F.)

  9. Protecting effects specifically from low doses of ionizing radiation to mammalian cells challenge the concept of linearity

    Energy Technology Data Exchange (ETDEWEB)

    Feinendegen, L.E. [Brookhaven National Lab., Upton, NY (United States). Medical Dept.; Bond, V.P. [Washington State Univ., Richland, WA (United States); Sondhaus, C.A. [Univ. of Arizona, Tucson, AZ (United States). Dept. of Radiology and Radiation Control Office; Altman, K.I. [Univ. of Rochester Medical Center, NY (United States). Dept. of Biochemistry and Biophysics

    1998-12-31

    This report examines the origin of tissue effects that may follow from different cellular responses to low-dose irradiation, using published data. Two principal categories of cellular responses are considered. One response category relates to the probability of radiation-induced DNA damage. The other category consists of low-dose induced changes in intracellular signaling that induce mechanisms of DNA damage control different from those operating at high levels of exposure. Modeled in this way, tissue is treated as a complex adaptive system. The interaction of the various cellular responses results in a net tissue dose-effect relation that is likely to deviate from linearity in the low-dose region. This suggests that the LNT hypothesis should be reexamined. The aim of this paper is to demonstrate that by use of microdosimetric concepts, the energy deposited in cell mass can be related to the occurrence of cellular responses, both damaging and defensive.

  10. Solar cell radiation handbook

    Science.gov (United States)

    Tada, H. Y.; Carter, J. R., Jr.; Anspaugh, B. E.; Downing, R. G.

    1982-01-01

    The handbook to predict the degradation of solar cell electrical performance in any given space radiation environment is presented. Solar cell theory, cell manufacturing and how they are modeled mathematically are described. The interaction of energetic charged particles radiation with solar cells is discussed and the concept of 1 MeV equivalent electron fluence is introduced. The space radiation environment is described and methods of calculating equivalent fluences for the space environment are developed. A computer program was written to perform the equivalent fluence calculations and a FORTRAN listing of the program is included. Data detailing the degradation of solar cell electrical parameters as a function of 1 MeV electron fluence are presented.

  11. Simple Benchmark Specifications for Space Radiation Protection

    Science.gov (United States)

    Singleterry, Robert C. Jr.; Aghara, Sukesh K.

    2013-01-01

    This report defines space radiation benchmark specifications. This specification starts with simple, monoenergetic, mono-directional particles on slabs and progresses to human models in spacecraft. This report specifies the models and sources needed to what the team performing the benchmark needs to produce in a report. Also included are brief descriptions of how OLTARIS, the NASA Langley website for space radiation analysis, performs its analysis.

  12. Donor-specific cell-based assays in studying sensitivity to low-dose radiation: a population-based perspective

    Directory of Open Access Journals (Sweden)

    Dora eIl'yasova

    2014-11-01

    Full Text Available Currently, a linear no-threshold model is used to estimate health risks associated with exposure to low-dose radiation, a prevalent exposure in the general population, because the direct estimation from epidemiological studies suffers from uncertainty. This model has been criticized based on unique biology of low-dose radiation. Whether the departure from linearity is toward increased or decreased risk is intensely debated. We present an approach based on individual radiosensitivity testing and discuss how individual radiosensitivity can be assessed with the goal to develop a quantifiable measure of cellular response that can be conducted via high-throughput population testing.

  13. Cell-specific precursor processing

    DEFF Research Database (Denmark)

    Rehfeld, Jens F; Bundgaard, Jens R

    2010-01-01

    The singular gene for a peptide hormone is expressed not only in a specific endocrine cell type but also in other endocrine cells as well as in entirely different cells such as neurons, adipocytes, myocytes, immune cells, and cells of the sex-glands. The cellular expression pattern for each gene...... varies with development, time and species. Endocrine regulation is, however, based on the release of a given hormone from an endocrine cell to the general circulation from whose cappilaries the hormone reaches the specific target cell elsewhere in the body. The widespread expression of hormone genes in...... different cells and tissues therefore requires control of biogenesis and secretion in order to avoid interference with the function of a specific hormonal peptide from a particular endocrine cell. Several mechanisms are involved in such control, one of them being cell-specific processing of prohormones. The...

  14. Adult Mesenchymal Stem Cells and Radiation Injury.

    Science.gov (United States)

    Kiang, Juliann G

    2016-08-01

    Recent understanding of the cellular and molecular signaling activations in adult mesenchymal stem cells (MSCs) has provided new insights into their potential clinical applications, particularly for tissue repair and regeneration. This review focuses on these advances, specifically in the context of self-renewal for tissue repair and recovery after radiation injury. Thus far, MSCs have been characterized extensively and shown to be useful in mitigation and therapy for acute radiation syndrome and cognitive dysfunction. Use of MSCs for treating radiation injury alone or in combination with additional trauma is foreseeable. PMID:27356065

  15. Chemical modification of neoplastic cell transformation by heavy ion radiation

    International Nuclear Information System (INIS)

    Quantitative data on chemical modification of neoplastic cell transformation by heavy-ion radiation was obtained using in-vitro cell transformation technique. The specific aims were 1) to test the potential effects of various chemicals on the expression of cell transformation, and 2) to systematically collect information on the mechanisms of expression and progression of cell transformation by ionizing radiation. Recent experimental studies with DMSO, 5-azacytidine, and dexamethasone suggest that DMSO can effectively suppress the neoplastic cell transformation by high-LET radiation and that some nonmutagenic changes in DNA may be important in modifying the expression, and progression of radiation-induced cell transformation

  16. Mesenchymal stem cells with high telomerase expression do not actively restore their chromosome arm specific telomere length pattern after exposure to ionizing radiation

    DEFF Research Database (Denmark)

    Graakjaer, Jesper; Christensen, Rikke; Kolvraa, Steen;

    2007-01-01

    BACKGROUND: Previous studies have demonstrated that telomeres in somatic cells are not randomly distributed at the end of the chromosomes. We hypothesize that these chromosome arm specific differences in telomere length (the telomere length pattern) may be actively maintained. In this study we...... investigate the existence and maintenance of the telomere length pattern in stem cells. For this aim we studied telomere length in primary human mesenchymal stem cells (hMSC) and their telomerase-immortalised counterpart (hMSC-telo1) during extended proliferation as well as after irradiation. Telomere lengths...... were measured using Fluorescence In Situ Hybridization (Q-FISH). RESULTS: A telomere length pattern was found to exist in primary hMSC's as well as in hMSC-telo1. This pattern is similar to what was previously found in lymphocytes and fibroblasts. The cells were then exposed to a high dose of ionizing...

  17. Effect of strand-specific excision repair on the spectra of mutations induced by benzo[a]pyrene-diol epoxide and ultraviolet radiation in diploid human cells

    International Nuclear Information System (INIS)

    To study the effect of excision repair on the spectra of mutations induced in diploid human cells by UV and ±-7β, 8α-dihydroxy-9α,10α-epoxy- 7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE), the author synchronized repair-proficient cells, treated them at the beginning of S phase or in G1 phase several hours prior to the onset of S phase, selected for thioguanine resistant cells, and determined the spectra of mutations in the coding region of the hyproxanthine(guanine)phosphoribosyl-transferase (HPRT) gene in the mutants. As a control, the spectra of mutations similarly induced in repair-deficient xeroderma pigmentosum (XP) cells were compared. There was no difference in the kinds of mutations observed in mutants derived from either cell strain treated with a particular mutagen either in S or in G1. With BPDE, the majority were G.C→T.A transversions; with UV, they were mainly G.C.→A.T transitions. The strand distribution of premutagenic lesions in mutants from repair-proficient cells treated in S or G1 differed significantly. The results strongly support the hypothesis that human cells preferentially repair UV- and BPDE-induced lesions from the transcribed strand of the HPRT gene. To test this, the rate of repair of BPDE adducts from individual strands of the HPRT gene was measured, using the UvrABC exinuclease and Southern hybridizations with strand-specific probes to detect lesions remaining. BPDE lesions were removed from the transcribed strand at a significantly faster rate than from the nontranscribed strand, consistent with my hypothesis. It was found that BPDE adducts were removed faster from either strand of the HPRT gene than from a transcriptionally inactive locus, indicating preferential repair of active genes. The results of these studies provide biochemical and biological evidence of strand-specific DNA repair of BPDE adducts in human cells

  18. Cell Phone RF Radiation

    Science.gov (United States)

    Abdul-Razzaq, Wathiq

    2015-01-01

    In a recent article in "Physics Today," Meredith and Redish emphasized the need to make introductory physics courses beneficial for life sciences majors. In this study, a lab activity is proposed to measure the intensity of electromagnetic waves emitted by cell phones and connect these measurements to various standards, biological…

  19. Antihistamine provides sex-specific radiation protection. [Ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Mickley, G.A.

    1981-04-01

    Rats suffer an early transient performance decrement immediately after a sufficiently large dose of ionizing radiation. However, it has been shown that males experience a more severe incapacitation than females. This sex difference has been attributed to the low estrogen levels in the male. In support of this notion, supplemental estrogens in castrated male rats have produced less-severe performance decrements post-irradiation. Antihistamines have also previously been shown to alleviate radiation's effect on behavior. The present study revealed that antihistamines are only effective in altering the behavioral incapacitation of sexually intact male subjects. This contrasts with previous work which indicates that estrogens can only benefit gonadectomized rats. These findings suggest that different mechanisms may underlie antihistamine and estrogen radiation protection.

  20. Antihistamine provides sex-specific radiation protection

    Energy Technology Data Exchange (ETDEWEB)

    Mickley, G.A.

    1981-04-01

    Rats suffer an early transient performance decrement immediately after a sufficiently large dose of ionizing radiation. However, it has been shown that males experience a more severe incapacitation than females. This sex difference has been attributed to the low estrogen levels in the male. In support of this notion, supplemental estrogens in castrated male rats have produced less-severe performance decrements post-irradiation. Antihistamines have also previously been shown to alleviate radiation's effect on behavior. The present study revealed that antihistamines are only effective in altering the behavioral incapacitation of sexually intact male subjects. This contrasts with previous work which indicates that estrogens can only benefit gonadectomized rats. These findings suggest that different mechanisms may underly antihistamine and estrogen radiation protection.

  1. Radiation-induced bystander effects in vivo are sex specific

    Energy Technology Data Exchange (ETDEWEB)

    Koturbash, Igor; Kutanzi, Kristy; Hendrickson, Karl; Rodriguez-Juarez, Rocio; Kogosov, Dmitry [Department of Biological Sciences, University of Lethbridge, Alberta T1K 3M4 (Canada); Kovalchuk, Olga [Department of Biological Sciences, University of Lethbridge, Alberta T1K 3M4 (Canada)], E-mail: olga.kovalchuk@uleth.ca

    2008-07-03

    Ionizing radiation (IR) effects span beyond the area of direct exposure and can be observed in neighboring and distant naive cells and organs. This phenomenon is termed a 'bystander effect'. IR effects in directly exposed tissue in vivo are epigenetically mediated and distinct in males and females. Yet, IR-induced bystander effects have never been explored in a sex-specificity domain. We used an in vivo mouse model, whereby the bystander effects are studied in spleen of male and female animals subjected to head exposure when the rest of the body is protected by a medical-grade lead shield. We analyzed the induction of DNA damage and alterations in global DNA methylation. Molecular parameters were correlated with cellular proliferation and apoptosis levels. The changes observed in bystander organs are compared to the changes in unexposed animals and animals exposed to predicted and measured scatter doses. We have found the selective induction of DNA damage levels, global DNA methylation, cell proliferation and apoptosis in exposed and bystander spleen tissue of male and female mice. Sex differences were significantly diminished in animals subjected to a surgical removal of gonads. These data constitute the first evidence of sex differences in radiation-induced bystander effects in mouse spleen in vivo. We show the role of sex hormones in spleen bystander responses and discuss implications of the observed changes.

  2. H-2 restriction specificity of T cells from H-2 incompatible radiation bone marrow chimeras: further evidence for the absence of crucial influence of the host/thymus environment on the generation of H-2 restricted TNP-specific T lymphocyte precursors

    International Nuclear Information System (INIS)

    Experiments were conducted to answer the questions related to (a) the role played by the antigen-presenting cells (APCs) present within the thymus and (b) the effect of radiation dose to the recipients on the H-2 restriction profile of TNP-specific cytotoxic T lymphocyte precursors (CTLP) recovered from spleens and/or thymuses of H-2 incompatible radiation bone marrow chimeras (BMC). The H-2 restriction profile of intrathymically differentiating TNP-specific CTLPs was also analyzed in order to test an argument that donor-H-2 restricted CTLP detected in spleens of H-2 incompatible BMC were due to the extrathymically differentiated T cells under the influence of donor-derived lymphoreticular cells. The results indicated the following: (i) splenic T cells from B10(H-2b) leads to (B10(H-2b) leads to B10.BR(H-2k)) chimeras, which were constructed by irradiating primary B10 leads to B10.BR chimeras with 1100 R and reconstituting them with donor-type (B10) bone marrow cells as long as 8 months after their construction, manifested restriction specificities for both donor- and host-type H-2, (ii) splenic T cells from two types of (B10 X B10.BR)F1 leads to B10 chimeras which were reconstituted after exposure of the recipients with either 900 or 1100 R with donor-type bone marrow cells generated both donor- and host-H-2 restricted TNP-specific cytotoxic T cells, and (iii) the TNP-specific CTLPs present in the regenerating thymuses of B10.BR leads to B10 and (B10 X B10.BR)F1 leads to B10 chimeras 4 weeks after their construction were also shown to manifest both donor- and host-H-2 restriction specificities. The significance of these findings on the H-2 restriction profile of CTLP generated in BMCs is discussed

  3. Data on biodistribution and radiation absorbed dose profile of a novel 64Cu-labeled high affinity cell-specific peptide for positron emission tomography imaging of tumor vasculature

    Directory of Open Access Journals (Sweden)

    Joseph R. Merrill

    2016-06-01

    Full Text Available New peptide-based diagnostic and therapeutic approaches hold promise for highly selective targeting of cancer leading to more precise and effective diagnostic and therapeutic modalities. An important feature of these approaches is to reach the tumor tissue while limiting or minimizing the dose to normal organs. In this context, efforts to design and engineer materials with optimal in vivo targeting and clearance properties are important. This Data In Brief article reports on biodistribution and radiation absorbed dose profile of a novel high affinity radiopeptide specific for bone marrow-derived tumor vasculature. Background information on the design, preparation, and in vivo characterization of this peptide-based targeted radiodiagnostic is described in the article “Synthesis and comparative evaluation of novel 64Cu-labeled high affinity cell-specific peptides for positron emission tomography of tumor vasculature” (Merrill et al., 2016 [1]. Here we report biodistribution measurements in mice and calculate the radiation absorbed doses to normal organs using a modified Medical Internal Radiation Dosimetry (MIRD methodology that accounts for physical and geometric factors and cross-organ beta doses.

  4. Dynamic alteration in H3 serine 10 phosphorylation is G1-phase specific during ionization radiation induced DNA damage response in human cells

    International Nuclear Information System (INIS)

    Highlights: • Loss of H3S10P in response to DNA damage is a universal phenomenon from G1 cells. • The loss happens predominantly from histone H3.3, a transcription activation mark. • Compaction of chromatin occurs during repair stage of DDR. • The alteration of H3S10P shows an inverse correlation with γH2AX. - Abstract: Chromatin acts as a natural barrier in DNA-damage recognition and repair. Histones undergo differential post-translational modification(s) to facilitate DNA damage response (DDR). Importance of modifications like phosphorylation of histone variant H2A.X in DNA repair is very well understood, however, ambiguous results exist in literature regarding the levels of certain histone modifications and their possible role in repair. In the present study, we have investigated in depth the alteration in the level of the highly dynamic histone mark H3S10P as it plays a dual role in different phases of the cell cycle. We show here that H3S10P decreases specifically from irradiated G1-enriched cells irrespective of the damaging agent or the cell line used in the study. Interestingly, the loss occurs predominantly from H3.3 variant which is a transcription activation mark like H3S10P itself, suggesting that the alteration might be implicated in transcription repression. The decrease in other transcription marks like H3K9Ac, H3K14Ac, H3K56Ac and H3S28P along with the occurrence of chromatin condensation in response to DNA damage in G1 phase strengthens the hypothesis. In addition, the alteration in the level of H3S10P shows an inverse correlation with that of γH2AX in a dose-dependent manner and probably occurs from the same mononucleosome. We propose that the drop in the levels of histone H3S10 phosphorylation is a universal phenomenon in response to DNA damage and is a trigger to induce transcription repressive state to facilitate repair

  5. Dynamic alteration in H3 serine 10 phosphorylation is G1-phase specific during ionization radiation induced DNA damage response in human cells

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Ajit K.; Bhattacharya, Saikat; Khan, Shafqat A.; Khade, Bharat; Gupta, Sanjay, E-mail: sgupta@actrec.gov.in

    2015-03-15

    Highlights: • Loss of H3S10P in response to DNA damage is a universal phenomenon from G1 cells. • The loss happens predominantly from histone H3.3, a transcription activation mark. • Compaction of chromatin occurs during repair stage of DDR. • The alteration of H3S10P shows an inverse correlation with γH2AX. - Abstract: Chromatin acts as a natural barrier in DNA-damage recognition and repair. Histones undergo differential post-translational modification(s) to facilitate DNA damage response (DDR). Importance of modifications like phosphorylation of histone variant H2A.X in DNA repair is very well understood, however, ambiguous results exist in literature regarding the levels of certain histone modifications and their possible role in repair. In the present study, we have investigated in depth the alteration in the level of the highly dynamic histone mark H3S10P as it plays a dual role in different phases of the cell cycle. We show here that H3S10P decreases specifically from irradiated G1-enriched cells irrespective of the damaging agent or the cell line used in the study. Interestingly, the loss occurs predominantly from H3.3 variant which is a transcription activation mark like H3S10P itself, suggesting that the alteration might be implicated in transcription repression. The decrease in other transcription marks like H3K9Ac, H3K14Ac, H3K56Ac and H3S28P along with the occurrence of chromatin condensation in response to DNA damage in G1 phase strengthens the hypothesis. In addition, the alteration in the level of H3S10P shows an inverse correlation with that of γH2AX in a dose-dependent manner and probably occurs from the same mononucleosome. We propose that the drop in the levels of histone H3S10 phosphorylation is a universal phenomenon in response to DNA damage and is a trigger to induce transcription repressive state to facilitate repair.

  6. Space radiation effects on plant and mammalian cells

    Science.gov (United States)

    Arena, C.; De Micco, V.; Macaeva, E.; Quintens, R.

    2014-11-01

    The study of the effects of ionizing radiation on organisms is related to different research aims. The current review emphasizes the studies on the effects of different doses of sparsely and densely ionizing radiation on living organisms, with the final purpose of highlighting specific and common effects of space radiation in mammals and plants. This topic is extremely relevant in the context of radiation protection from space environment. The response of different organisms to ionizing radiation depends on the radiation quality/dose and/or the intrinsic characteristics of the living system. Macromolecules, in particular DNA, are the critical targets of radiation, even if there is a strong difference between damages encountered by plant and mammalian cells. The differences in structure and metabolism between the two cell types are responsible for the higher resistance of the plant cell compared with its animal counterpart. In this review, we report some recent findings from studies performed in Space or on Earth, simulating space-like levels of radiation with ground-based facilities, to understand the effect of ionizing radiation on mammalian and plant cells. In particular, our attention is focused on genetic alterations and repair mechanisms in mammalian cells and on structures and mechanisms conferring radioresistance to plant cells.

  7. PD-L1-specific T cells

    DEFF Research Database (Denmark)

    Ahmad, Shamaila Munir; Borch, Troels Holz; Hansen, Morten;

    2016-01-01

    -specific T cells that recognize both PD-L1-expressing immune cells and malignant cells. Thus, PD-L1-specific T cells have the ability to modulate adaptive immune reactions by reacting to regulatory cells. Thus, utilization of PD-L1-derived T cell epitopes may represent an attractive vaccination strategy...... for targeting the tumor microenvironment and for boosting the clinical effects of additional anticancer immunotherapy. This review summarizes present information about PD-L1 as a T cell antigen, depicts the initial findings about the function of PD-L1-specific T cells in the adjustment of immune responses...

  8. Mitochondrial mutagenesis induced by tumor-specific radiation bystander effects.

    LENUS (Irish Health Repository)

    Gorman, Sheeona

    2012-02-01

    The radiation bystander effect is a cellular process whereby cells not directly exposed to radiation display cellular alterations similar to directly irradiated cells. Cellular targets including mitochondria have been postulated to play a significant role in this process. In this study, we utilized the Random Mutation Capture assay to quantify the levels of random mutations and deletions in the mitochondrial genome of bystander cells. A significant increase in the frequency of random mitochondrial mutations was found at 24 h in bystander cells exposed to conditioned media from irradiated tumor explants (p = 0.018). CG:TA mutations were the most abundant lesion induced. A transient increase in the frequency of random mitochondrial deletions was also detected in bystander cells exposed to conditioned media from tumor but not normal tissue at 24 h (p = 0.028). The increase in both point mutations and deletions was transient and not detected at 72 h. To further investigate mitochondrial dysfunction, mitochondrial membrane potential and reactive oxygen species were assessed in these bystander cells. There was a significant reduction in mitochondrial membrane potential and this was positively associated with the frequency of random point mutation and deletions in bystander cells treated with conditioned media from tumor tissue (r = 0.71, p = 0.02). This study has shown that mitochondrial genome alterations are an acute consequence of the radiation bystander effect secondary to mitochondrial dysfunction and suggests that this cannot be solely attributable to changes in ROS levels alone.

  9. Haemopoietic cell renewal in radiation fields.

    Science.gov (United States)

    Fliedner, T M; Nothdurft, W; Tibken, B; Hofer, E; Weiss, M; Kindler, H

    1994-10-01

    Space flight activities are inevitably associated with a chronic exposure of astronauts to a complex mixture of ionising radiation. Although no acute radiation consequences are to be expected as a rule, the possibility of Solar Particle Events (SPE) associated with relatively high doses of radiation (1 or more Gray) cannot be excluded. It is the responsibility of physicians in charge of the health of astronauts to evaluate before, during and after space flight activities the functional status of haemopoietic cell renewal. Chronic low level exposure of dogs indicate that daily gamma-exposure doses below about 2 cGy are tolerated for several years as far as blood cell concentrations are concerned. However, the stem cell pool may be severely affected. The maintenance of sufficient blood cell counts is possible only through increased cell production to compensate for the radiation inflicted excess cell loss. This behaviour of haemopoietic cell renewal during chronic low level exposure can be simulated by bioengineering models of granulocytopoiesis. It is possible to define a "turbulence region" for cell loss rates, below which an prolonged adaptation to increased radiation fields can be expected to be tolerated. On the basis of these experimental results, it is recommended to develop new biological indicators to monitor haemopoietic cell renewal at the level of the stem cell pool using blood stem cells in addition to the determination of cytokine concentrations in the serum (and other novel approaches). To prepare for unexpected haemopoietic effects during prolonged space missions, research should be increased to modify the radiation sensitivity of haemopoietic stem cells (for instance by the application of certain regulatory molecules). In addition, a "blood stem cell bank" might be established for the autologous storage of stem cells and for use in space activities keeping them in a radiation protected container. PMID:11539991

  10. Epidermal stem cells response to radiative genotoxic stress

    International Nuclear Information System (INIS)

    Human skin is the first organ exposed to various environmental stresses, which requires the development by skin stem cells of specific mechanisms to protect themselves and to ensure tissue homeostasis. As stem cells are responsible for the maintenance of epidermis during individual lifetime, the preservation of genomic integrity in these cells is essential. My PhD aimed at exploring the mechanisms set up by epidermal stem cells in order to protect themselves from two genotoxic stresses, ionizing radiation (Gamma Rays) and ultraviolet radiation (UVB). To begin my PhD, I have taken part of the demonstration of protective mechanisms used by keratinocyte stem cells after ionizing radiation. It has been shown that these cells are able to rapidly repair most types of radiation-induced DNA damage. Furthermore, we demonstrated that this repair is activated by the fibroblast growth factor 2 (FGF2). In order to know if this protective mechanism is also operating in cutaneous carcinoma stem cells, we investigated the response to gamma Rays of carcinoma stem cells isolated from a human carcinoma cell line. As in normal keratinocyte stem cells, we demonstrated that cancer stem cells could rapidly repair radio-induced DNA damage. Furthermore, fibroblast growth factor 2 also mediates this repair, notably thanks to its nuclear isoforms. The second project of my PhD was to study human epidermal stem cells and progenitors responses to UVB radiation. Once cytometry and irradiation conditions were set up, the toxicity of UVB radiation has been evaluate in the primary cell model. We then characterized UVB photons effects on cell viability, proliferation and repair of DNA damage. This study allowed us to bring out that responses of stem cells and their progeny to UVB are different, notably at the level of part of their repair activity of DNA damage. Moreover, progenitors and stem cells transcriptomic responses after UVB irradiation have been study in order to analyze the global

  11. Specific inhibition of Wee1 kinase and Rad51 recombinase: A strategy to enhance the sensitivity of leukemic T-cells to ionizing radiation-induced DNA double-strand breaks

    Energy Technology Data Exchange (ETDEWEB)

    Havelek, Radim, E-mail: radim.havelek@upce.cz [Department of Biological and Biochemical Sciences, Faculty of Chemical Technology, University of Pardubice, Studentska 573, Pardubice 532 10 (Czech Republic); Cmielova, Jana [Department of Medical Biochemistry, Faculty of Medicine in Hradec Kralove, Charles University in Prague, Simkova 870, Hradec Kralove 500 38 (Czech Republic); Kralovec, Karel; Bruckova, Lenka; Bilkova, Zuzana; Fousova, Ivana [Department of Biological and Biochemical Sciences, Faculty of Chemical Technology, University of Pardubice, Studentska 573, Pardubice 532 10 (Czech Republic); Sinkorova, Zuzana; Vavrova, Jirina [Department of Radiobiology, Faculty of Military Health Sciences, University of Defence in Brno, Trebesska 1575, Hradec Kralove 500 01 (Czech Republic); Rezacova, Martina [Department of Medical Biochemistry, Faculty of Medicine in Hradec Kralove, Charles University in Prague, Simkova 870, Hradec Kralove 500 38 (Czech Republic)

    2014-10-24

    Highlights: • Pre-treatment with the inhibitors increased the sensitivity of Jurkat cells to irradiation. • Combining both inhibitors together resulted in a G2 cell cycle arrest abrogation in Jurkat. • Jurkat cells pre-treated with inhibitors were positive for γH2AX foci 24 h upon irradiation. • Pre-treatment with Rad51 RI-1 had no effect on apoptosis induction in MOLT-4 cells. • When dosed together, the combination decreased MOLT-4 cell survival. - Abstract: Present-day oncology sees at least two-thirds of cancer patients receiving radiation therapy as a part of their anticancer treatment. The objectives of the current study were to investigate the effects of the small molecule inhibitors of Wee1 kinase II (681641) and Rad51 (RI-1) on cell cycle progression, DNA double-strand breaks repair and apoptosis following ionizing radiation exposure in human leukemic T-cells Jurkat and MOLT-4. Pre-treatment with the Wee1 681641 or Rad51 RI-1 inhibitor alone increased the sensitivity of Jurkat cells to irradiation, however combining both inhibitors together resulted in a further enhancement of apoptosis. Jurkat cells pre-treated with inhibitors were positive for γH2AX foci 24 h upon irradiation. MOLT-4 cells were less affected by inhibitors application prior to ionizing radiation exposure. Pre-treatment with Rad51 RI-1 had no effect on apoptosis induction; however Wee1 681641 increased ionizing radiation-induced cell death in MOLT-4 cells.

  12. Radiation Enhances Regulatory T Cell Representation

    Energy Technology Data Exchange (ETDEWEB)

    Kachikwu, Evelyn L.; Iwamoto, Keisuke S.; Liao, Yu-Pei; DeMarco, John J.; Agazaryan, Nzhde [Department of Radiation Oncology, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Economou, James S. [Department of Surgical Oncology, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); McBride, William H. [Department of Radiation Oncology, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Schaue, Doerthe, E-mail: dschaue@mednet.ucla.edu [Department of Radiation Oncology, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States)

    2011-11-15

    Purpose: Immunotherapy could be a useful adjunct to standard cytotoxic therapies such as radiation in patients with micrometastatic disease, although successful integration of immunotherapy into treatment protocols will require further understanding of how standard therapies affect the generation of antitumor immune responses. This study was undertaken to evaluate the impact of radiation therapy (RT) on immunosuppressive T regulatory (Treg) cells. Methods and Materials: Treg cells were identified as a CD4{sup +}CD25{sup hi}Foxp3{sup +} lymphocyte subset, and their fate was followed in a murine TRAMP C1 model of prostate cancer in mice with and without RT. Results: CD4{sup +}CD25{sup hi}Foxp3{sup +} Treg cells increased in immune organs after local leg or whole-body radiation. A large part, but not all, of this increase after leg-only irradiation could be ascribed to radiation scatter and Treg cells being intrinsically more radiation resistant than other lymphocyte subpopulations, resulting in their selection. Their functional activity on a per-cell basis was not affected by radiation exposure. Similar findings were made with mice receiving local RT to murine prostate tumors growing in the leg. The importance of the Treg cell population in the response to RT was shown by systemic elimination of Treg cells, which greatly enhanced radiation-induced tumor regression. Conclusions: We conclude that Treg cells are more resistant to radiation than other lymphocytes, resulting in their preferential increase. Treg cells may form an important homeostatic mechanism for tissues injured by radiation, and in a tumor context, they may assist in immune evasion during therapy. Targeting this population may allow enhancement of radiotherapeutic benefit through immune modulation.

  13. Radiation Enhances Regulatory T Cell Representation

    International Nuclear Information System (INIS)

    Purpose: Immunotherapy could be a useful adjunct to standard cytotoxic therapies such as radiation in patients with micrometastatic disease, although successful integration of immunotherapy into treatment protocols will require further understanding of how standard therapies affect the generation of antitumor immune responses. This study was undertaken to evaluate the impact of radiation therapy (RT) on immunosuppressive T regulatory (Treg) cells. Methods and Materials: Treg cells were identified as a CD4+CD25hiFoxp3+ lymphocyte subset, and their fate was followed in a murine TRAMP C1 model of prostate cancer in mice with and without RT. Results: CD4+CD25hiFoxp3+ Treg cells increased in immune organs after local leg or whole-body radiation. A large part, but not all, of this increase after leg-only irradiation could be ascribed to radiation scatter and Treg cells being intrinsically more radiation resistant than other lymphocyte subpopulations, resulting in their selection. Their functional activity on a per-cell basis was not affected by radiation exposure. Similar findings were made with mice receiving local RT to murine prostate tumors growing in the leg. The importance of the Treg cell population in the response to RT was shown by systemic elimination of Treg cells, which greatly enhanced radiation-induced tumor regression. Conclusions: We conclude that Treg cells are more resistant to radiation than other lymphocytes, resulting in their preferential increase. Treg cells may form an important homeostatic mechanism for tissues injured by radiation, and in a tumor context, they may assist in immune evasion during therapy. Targeting this population may allow enhancement of radiotherapeutic benefit through immune modulation.

  14. Cdc42-mediated tubulogenesis controls cell specification

    DEFF Research Database (Denmark)

    Kesavan, Gokul; Sand, Fredrik Wolfhagen; Greiner, Thomas Uwe;

    2009-01-01

    Understanding how cells polarize and coordinate tubulogenesis during organ formation is a central question in biology. Tubulogenesis often coincides with cell-lineage specification during organ development. Hence, an elementary question is whether these two processes are independently controlled......, or whether proper cell specification depends on formation of tubes. To address these fundamental questions, we have studied the functional role of Cdc42 in pancreatic tubulogenesis. We present evidence that Cdc42 is essential for tube formation, specifically for initiating microlumen formation and later...... for maintaining apical cell polarity. Finally, we show that Cdc42 controls cell specification non-cell-autonomously by providing the correct microenvironment for proper control of cell-fate choices of multipotent progenitors. For a video summary of this article, see the PaperFlick file with the Supplemental Data...

  15. The myth of cell phone radiation

    OpenAIRE

    Natarajan, Vasant

    2012-01-01

    We discuss the purported link between cell-phone radiation and cancer. We show that it is inconsistent with the photoelectric effect, and that epidemiological studies of any link have no scientific basis.

  16. Comet assay analysis of repair of DNA strand breaks in normal and deficient human cells exposed to radiations and chemicals. Evidence for a repair pathway specificity of DNA ligation

    International Nuclear Information System (INIS)

    The induction and resealing of DNA strand breaks in a cell line with a proven defect in DNA ligase I, 46BR, and in two Bloom's syndrome cell lines. YBL6 and GM 1492, were compared to those observed in normal human 1BR/3 fibroblasts after treatment with a variety of genotoxic agents whose lesions are processed by different repair pathways. This analysis was performed using the single-cell gel electrophoresis assay. The three types of cells were found to have similar capabilities to recognize and incise ultraviolet photoproducts and also demonstrated similar amounts of DNA breaks immediately after γ irradiation. During post-treatment incubation, 46BR cells showed a marked DNA re-ligation defect after ultraviolet radiation damage, GM 1492 cells demonstrated a highly reduced DNA joining ability after relatively high doses of ultraviolet radiation, and YBL6 cells were particularly affected in DNA re-ligation after damage by 4-nitroquinoline-1-oxide. The two Bloom's syndrome cell lines and 46BR cells had a nearly normal ability to reseal breaks resulting from γ irradiation or treatment with xanthine plus xanthine oxidase. These findings suggest that different DNA ligases may be involved in different DNA repair pathways in human cells. 60 refs., 7 figs

  17. A specific case: Cosmic radiation exposures of flight crew

    International Nuclear Information System (INIS)

    Full text: The average annual effective dose due to occupational cosmic radiation exposure is 3.0 mSv (about 60% neutrons), which is higher than that due to other enhanced natural sources such as coal mining, non-coal mining or mineral processing according to the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) 2000 Report. Individual variability in annual exposures can be up to 25 fold (0.25 mSv/a), depending on the routes flown, which are often related to seniority in the profession. The collective dose for aircrew is 320 man Sv/a (UNSCEAR 1993 Report). In the specific case of cosmic radiation exposure of aircrew, the radiation control options include rotation of staff for reduction in individual hours worked, reduction in aircraft altitudes, reduction in flight route latitudes and postponement or rerouting of flights during known solar particle events. In the classic occupational hygiene exposure control paradigm, these measures would be categorized as administrative controls: reducing the time exposed or increasing the distance to source. Clearly, there are no feasible engineering controls or personal protective controls such as aircraft or personal shielding. International Commission on Radiological Protection Publication 60 (1991) provided international recommendations that practices involving radiation exposures be justified by benefit to individuals or society, that protection be optimized by constraining individual doses or risks, and that limits be set for individual doses and risks. Additionally, proposed interventions should do more harm than good and the cost benefit should be maximized. However, from a regulatory standpoint, differences exist between countries in the approach taken. In the United States of America, aircrew are not yet considered radiation workers and occupational exposures to cosmic radiation are still treated as unregulated natural background radiation. The US Federal Aviation Administration (FAA

  18. High Radiation Resistance IMM Solar Cell

    Science.gov (United States)

    Pan, Noren

    2015-01-01

    Due to high launch costs, weight reduction is a key driver for the development of new solar cell technologies suitable for space applications. This project is developing a unique triple-junction inverted metamorphic multijunction (IMM) technology that enables the manufacture of very lightweight, low-cost InGaAsP-based multijunction solar cells. This IMM technology consists of indium (In) and phosphorous (P) solar cell active materials, which are designed to improve the radiation-resistant properties of the triple-junction solar cell while maintaining high efficiency. The intrinsic radiation hardness of InP materials makes them of great interest for building solar cells suitable for deployment in harsh radiation environments, such as medium Earth orbit and missions to the outer planets. NASA Glenn's recently developed epitaxial lift-off (ELO) process also will be applied to this new structure, which will enable the fabrication of the IMM structure without the substrate.

  19. Ionizing radiation induces stemness in cancer cells.

    Directory of Open Access Journals (Sweden)

    Laura Ghisolfi

    Full Text Available The cancer stem cell (CSC model posits the presence of a small number of CSCs in the heterogeneous cancer cell population that are ultimately responsible for tumor initiation, as well as cancer recurrence and metastasis. CSCs have been isolated from a variety of human cancers and are able to generate a hierarchical and heterogeneous cancer cell population. CSCs are also resistant to conventional chemo- and radio-therapies. Here we report that ionizing radiation can induce stem cell-like properties in heterogeneous cancer cells. Exposure of non-stem cancer cells to ionizing radiation enhanced spherogenesis, and this was accompanied by upregulation of the pluripotency genes Sox2 and Oct3/4. Knockdown of Sox2 or Oct3/4 inhibited radiation-induced spherogenesis and increased cellular sensitivity to radiation. These data demonstrate that ionizing radiation can activate stemness pathways in heterogeneous cancer cells, resulting in the enrichment of a CSC subpopulation with higher resistance to radiotherapy.

  20. Germ cell specification and regeneration in planarians.

    Science.gov (United States)

    Newmark, P A; Wang, Y; Chong, T

    2008-01-01

    In metazoans, two apparently distinct mechanisms specify germ cell fate: Determinate specification (observed in animals including Drosophila, Caenorhabditis elegans, zebra fish, and Xenopus) uses cytoplasmic factors localized to specific regions of the egg, whereas epigenetic specification (observed in many basal metazoans, urodeles, and mammals) involves inductive interactions between cells. Much of our understanding of germ cell specification has emerged from studies of model organisms displaying determinate specification. In contrast, our understanding of epigenetic/inductive specification is less advanced and would benefit from studies of additional organisms. Freshwater planarians--widely known for their remarkable powers of regeneration--are well suited for studying the mechanisms by which germ cells can be induced. Classic experiments showed that planarians can regenerate germ cells from body fragments entirely lacking reproductive structures, suggesting that planarian germ cells could be specified by inductive signals. Furthermore, the availability of the genome sequence of the planarian Schmidtea mediterranea, coupled with the animal's susceptibility to systemic RNA interference (RNAi), facilitates functional genomic analyses of germ cell development and regeneration. Here, we describe recent progress in studies of planarian germ cells and frame some of the critical unresolved questions for future work.

  1. Albendazole sensitizes cancer cells to ionizing radiation

    International Nuclear Information System (INIS)

    Brain metastases afflict approximately half of patients with metastatic melanoma (MM) and small cell lung cancer (SCLC) and represent the direct cause of death in 60 to 70% of those affected. Standard of care remains ineffective in both types of cancer with the challenge of overcoming the blood brain barrier (BBB) exacerbating the clinical problem. Our purpose is to determine and characterize the potential of albendazole (ABZ) as a cytotoxic and radiosensitizing agent against MM and SCLC cells. Here, ABZ's mechanism of action as a DNA damaging and microtubule disrupting agent is assessed through analysis of histone H2AX phosphorylation and cell cyle progression. The cytotoxicity of ABZ alone and in combination with radiation therapy is determined though clonogenic cell survival assays in a panel of MM and SCLC cell lines. We further establish ABZ's ability to act synergistically as a radio-sensitizer through combination index calculations and apoptotic measurements of poly (ADP-ribose) polymerase (PARP) cleavage. ABZ induces DNA damage as measured by increased H2AX phosphorylation. ABZ inhibits the growth of MM and SCLC at clinically achievable plasma concentrations. At these concentrations, ABZ arrests MM and SCLC cells in the G2/M phase of the cell cycle after 12 hours of treatment. Exploiting the notion that cells in the G2/M phase are the most sensitive to radiation therapy, we show that treatment of MM and SCLC cells treated with ABZ renders them more sensitive to radiation in a synergistic fashion. Additionally, MM and SCLC cells co-treated with ABZ and radiation exhibit increased apoptosis at 72 hours. Our study suggests that the orally available antihelminthic ABZ acts as a potent radiosensitizer in MM and SCLC cell lines. Further evaluation of ABZ in combination with radiation as a potential treatment for MM and SCLC brain metastases is warranted

  2. Ionizing radiation delivered by specific antibody is therapeutic against a fungal infection

    Science.gov (United States)

    Dadachova, Ekaterina; Nakouzi, Antonio; Bryan, Ruth A.; Casadevall, Arturo

    2003-09-01

    There is an urgent need for new antimicrobial therapies to combat drug resistance, new pathogens, and the relative inefficacy of current therapy in compromised hosts. Ionizing radiation can kill microorganisms quickly and efficiently, but this modality has not been exploited as a therapeutic antimicrobial strategy. We have developed methods to target ionizing radiation to a fungal cell by labeling a specific mAb with the therapeutic radioisotopes Rhenium-188 and Bismuth-213. Radiolabeled antibody killed cells of human pathogenic fungus Cryptococcus neoformans in vitro, thus converting an antibody with no inherent antifungal activity into a microbicidal molecule. Administration of radiolabeled antibody to mice with C. neoformans infection delivered 213Bi and 188Re to the sites of infection, reduced their organ fungal burden, and significantly prolonged their survival without apparent toxicity. This study establishes the principle that targeted radiation can be used for the therapy of an infectious disease, and suggests that it may have wide applicability as an antimicrobial strategy.

  3. Apoptin: specific killer of tumor cells?

    Science.gov (United States)

    Tavassoli, M; Guelen, L; Luxon, B A; Gäken, J

    2005-08-01

    In the early 1990s it was discovered that the VP3/Apoptin protein encoded by the Chicken Anemia virus (CAV) possesses an inherent ability to specifically kill cancer cells. Apoptin was found to be located in the cytoplasm of normal cells while in tumor cells it was localized mainly in the nucleus.(1) These differences in the localization pattern were suggested to be the main mechanism by which normal cells show resistance to Apoptin-mediated cell killing. Although the mechanism of action of Apoptin is presently unknown, it seems to function by the induction of programmed cell death (PCD) after translocation from the cytoplasm to the nucleus and arresting the cell cycle at G2/M, possibly by interfering with the cyclosome.(2) In addition, cancer specific phosphorylation of Threonine residue 108 has been suggested to be important for Apoptin's function to kill tumor cells.(3) In contrast to the large number of publications reporting that nuclear localization, induction of PCD and phosphorylation of Apoptin is restricted to cancer cells, several recent studies have shown that Apoptin has the ability to migrate to the nucleus and induce PCD in some of the normal cell lines tested. There is evidence that high protein expression levels as well as the cellular growth rate may influence Apoptin's ability to specifically kill tumor cells. Thus far both in vitro and in vivo studies indicate that Apoptin is a powerful apoptosis inducing protein with a promising prospective utility in cancer therapy. However, here we show that several recent findings contradict some of the earlier results on the tumor specificity of Apoptin, thus creating some controversy in the field. The aim of this article is to review the available data, some published and some unpublished, which either agree or contradict the reported "black and white" tumor cell specificity of Apoptin. Understanding what factors appear to influence its function should help to develop Apoptin into a potent anti

  4. Stem cells and radiation: effects in targeted and non-targeted cells

    International Nuclear Information System (INIS)

    The renewing tissues of the body are hierarchically organized and maintained by a small population of self-maintaining stem cells that are important targets for malignant transformation and also for gene therapy and tissue engineering approaches in regenerative medicine. Deleterious effects of toxic insults such as ionizing radiation may be due to stem cell death, with consequent loss of mature functional cells, or to stem cell damage that leads to aberrant responses to regulatory mechanisms. However, because the homeostatic regulation of these tissues is complex (involving intercellular signalling and cellular interactions that control cell proliferation, differentiation and death) radiation effects on stromal cells that perturb the microenvironmental control may also result in deleterious effects on the stem cell compartment. The rapidly developing fields of research investigating radiation-induced genomic instability and bystander effects also indicate that radiation effects on stem cells can be indirect. Although the non-targeted mechanisms responsible for bystander effects and the induction and maintenance of the inducible instability phenotype are not understood, inter-cellular signalling and free radical-mediated processes may be common features. Inter-cellular signalling and production of free radicals are also features of inflammatory responses; a recently identified indirect consequence of radiation with the potential for both persisting and bystander-mediated damage as well as for conferring a predisposition to malignancy. The production of clastogenic factors and their capacity for indirect cell damage after irradiation, the involvement of stromal cells in malignancy and bystander-mediated genetic instability may all reflect aspects of non-specific inflammatory-type responses to radiation-induced stress and injury. Recent investigations demonstrating that radiation-induced signalling processes are influenced by tissue-specific and genetic factors add

  5. The radiation effects on the living cell

    International Nuclear Information System (INIS)

    This publication is a presentation of particular points discussed during the colloquium of the 15-18 june 1999, for which scientific researches are performed at the CEA/CNRS. They deal with the radiobiology, for the radiation effects on living matter; with the DNA, for the knowledge and repair mechanisms on cells submitted to ionizing radiations; with the exposition to UV in correlation with neoplasms; with the P53 gene which is a tumour suppressor. (A.L.B.)

  6. Apoptin: Specific killer of tumor cells?

    OpenAIRE

    Tavassoli, M; Guelen, L.; Luxon, B. A.; Gäken, J

    2005-01-01

    In the early 1990s it was discovered that the VP3/Apoptin protein encoded by the Chicken Anemia virus (CAV) possesses an inherent ability to specifically kill cancer cells. Apoptin was found to be located in the cytoplasm of normal cells while in tumor cells it was localized mainly in the nucleus.1 These differences in the localization pattern were suggested to be the main mechanism by which normal cells show resistance to Apoptin-mediated cell killing. Although the mechanism of action of Apo...

  7. Cell-Specific Aptamers as Emerging Therapeutics

    OpenAIRE

    Cindy Meyer; Ulrich Hahn; Andrea Rentmeister

    2011-01-01

    Aptamers are short nucleic acids that bind to defined targets with high affinity and specificity. The first aptamers have been selected about two decades ago by an in vitro process named SELEX (systematic evolution of ligands by exponential enrichment). Since then, numerous aptamers with specificities for a variety of targets from small molecules to proteins or even whole cells have...

  8. Tissue specific promoters improve the localization of radiation-inducible gene expression

    International Nuclear Information System (INIS)

    Purpose: Site-specific activation of gene expression can be achieved by the use of a promoter that is induced by physical agents such as x-rays. The purpose of the present study was to determine whether site-specific activation of gene therapy can also be achieved within the vascular endothelium by use of radiation-inducible promoters. We studied induction of promoter-reporter gene constructs using previously identified radiation-promoters from c-jun, c-fos, Egr-1, ICAM-1, ELAM-1 after transfection into in the vascular endothelium. Methods: The following radiation-inducible genetic constructs were created: The ELAM-1 promoter fragment was cloned into pOGH to obtain the pE-sel(-587 +35)GH reporter construct. The ICAM-1 promoter fragment (-1162/+1) was cloned upstream of the CAT coding region of the pCAT-plasmid (Promega) after removal of the SV40 promoter by Bgl2/Stu1 digestion to create the pBS-CAT plasmid. The 132 to +170 bp segment of the 5' untranslated region of the c-jun promoter was cloned to the CAT reporter gene to create the -132/+170 cjun-CAT. The Egr-1 promoter fragment (-425/+75) was cloned upstream of the CAT coding region to create the pE425-CAT plasmid. Tandem repeats of the AP-1 binding site were cloned upstream of the CAT coding region (3 xTRE-CAT). Tandem repeats of the Egr binding site (EBS) were cloned upstream of the CAT coding region (EBS-CAT). Human vascular endothelial cells from both large vessel and small vessel origin (HUVEC and HMEC), as well as human tumor cell lines were transfected with plasmids -132/+170 cjun-CAT, pE425-CAT, 3 xTRE-CAT, EBS-CAT, pE-sel-GH and pBS-CAT by use of liposomes. Humor tumor cell lines included SQ20B (squamous), RIT3 (sarcoma), and HL525 (leukemia). Each plasmid was cotransfected with a plasmid containing a CMV promoter linked to the LacZ gene (1 μg). Transfected cells were treated with mock irradiation or x-rays. Cell extracts were assayed for reporter gene expression. Results: Radiation-induced gene

  9. Countermeasure development : Specific Immunoprophylaxis and Immunotherapy of Combined Acute Radiation Syndromes.

    Science.gov (United States)

    Popov, Dmitri; Maliev, Slava

    Introduction: Combined Acute Radiation Syndromes (CARS) are extremely severe injuries. Combination of Radiation and Thermal factors induce development of the acute pathologi-cal processes in irradiated mammals: systemic inflammatory response syndrome (SIRS), toxic multiple organ injury (TMOI), toxic multiple organ dysfunction syndromes (TMOD), toxic multiple organ failure (TMOF). Also, high doses of Radiation and Thermal injury induce for-mation of following Toxin groups: A. Specific Radiation Toxins; B. Specific Thermal Toxins; C. Nonspecific Histiogenic Pro-inflammatory and Inflammatory Toxins (NHIT). Specific Radi-ation Toxins (SRT) include four major group of Toxins: Cerebrovascular Radiation Toxins (Cv RT), Cardiovascular Radiation Toxins (Cr RT), Gastrointestinal Radiation Toxins (Gi RT), and Hematopoietic Radiation Toxins (Hp RT). CvRT, Cr RT, Gi RT groups of toxins are defined as Neurotoxins and Hp RT group is defined as Hematotoxins. Specific Thermal Toxins (STT) were isolated from the burned skin (Voul S., Colker I. 1972). The group of Nonspecific Histio-genic Inflammatory Toxins (NHIT) includes high amount of tissue toxins which are peptides with medium molecular weight. This group of polypeptides can be a significant factor as a part of developing of the general inflammation reaction. However, NHIT toxins can't induce many reactions and changes which are specific for radiation. Specific Radiation Toxins (SRT) can induce specific processes and reactions such as clonogenic cell death -programmed apoptotic necrosis. Although besides high doses of radiation, other forms of cell death such as Pyroptosis or Oncosis should be considered. We postulate that NHIT toxins are similar for high doses of radiation and thermal injury. Specific Radiation Toxins (SRT) are induced by high doses of radiation. Specific Thermal Toxins (STT) toxins which formation is induced by a Thermal Factor are different from SRT. Administration of STT toxins or NHIT toxins (IV or IM) to

  10. The Effect of 5-FU and Radiation on A549 Cells In Vitro

    International Nuclear Information System (INIS)

    Effects of ionizing radiation alone and combined with chemotherapy on tumor growth and it clonal specificity Monitored by changes in distribution of chromosome number were studies in A549 cell line originated from human adenocarcinoma of the lung. Radiation (300 rad, 600 rad and 900 rad) were delivered with or without 5-FU. Forty eight hours later, 57.5% of growth inhibition of cell was Seen in cells treated with 5-FU concentration of 0.47g/ml for 24 hr exposure. Cell survival carves after radiation with and without 5-FU were made. Chromosomal analysis of cells in metaphase in control, and in cells treated with 300 rad of radiation, or 0.47g/ml of 5-FU treatment, and combined treatment of cloth were 77ne to examine the changes in ploidy and number of chromosome. Radiation combined with 5-FU enhanced growth inhibition of A549 cells. However, no evidence of synergetic effects in growth inhibition was observed in the cells treated with the combination therapy. Pattern of chromosomal distribution of survived cells were shifted from hyperploidy to hypoploidy by single dose of radiation(300 rad). As radiation dose increased a large number of hypoploidy cells were observed. Following treatment of cells with 5-FU, chomosomal distribution of survived cells were also shifted to hypodiploidy, which were seen in cells treated with radiation. The cell treated with 5-FU and followed by radiation within 24 hrs had cell with increased number of hypodiploidy cells. Almost same type of chromosomal changes were reproduced in cells treated with combined treatment with radiation and 5-FU. Minor differences were that cells with fewer number of chromosome were more frequent in cells treated with combined therapy. Further increase in cells of hypoploidy(93%) having 1-10 chromosome were induced by additional radiation. Therefore, the enhanced therapeutic effect of 5-FU combined with radiation of A549 cells appeared to be additive rather than synergistic

  11. Atypical radiation response of SCID cells

    Science.gov (United States)

    Chawapun, Nisa

    Murine SCID (severe combined immune deficiency) cells are well known for their defect in DNA double-strand break repair and in variable(diversity)joining [V(D)J] recombination due to a mutation in a catalytic subunit of DNA-dependent protein kinase (DNA-PKcs). As a consequence, scid cells are hypersensitive to ionizing radiation. The present study showed that asynchronous populations of scid cells were about two-fold more sensitive than Balb/c with respect to cell killing and the defect in scid cells was corrected by complementation with human chromosome 8. Analysis of the survival of synchronized populations as a function of the cell cycle revealed that while scid cells were hypersensitive in all cell cycle phases compared to wild-type cells, this hypersensitivity is even more pronounced in G1 phase. The hypersensitivity reduced as the cells progressed into S phase suggested that homologous recombination repair plays a role. The results imply that there are at least two pathways for the repair of DSB DNA, consistent with a model previously proposed by others. The scid cells were also more sensitive to UVC light (254 nm) killing as compared to wild type cells by clonogenic survival. Using a host cell reactivation (HCR) assay to study the nucleotide excision repair (NER) which is the major repair pathway for UV-photoproducts, the results showed that NER in scid cells was not as efficient as CB- 17. This suggests that DNA-PK is involved in NER as well as non-homologous end-joining (NHEJ) DSB repair which is responsible for ionizing radiation sensitivity in scid cells. Repair in scid cells was not totally absent as shown by low dose rate sparing of cell killing after exposure to 137Cs γ-rays at dose rate of 0.6 cGy/h, 1.36 cGy/h, 6 cGy/h as compared to high dose rate at 171 cGy/min, although this phenomenon could be explained partly by proliferation. However, for radiation induced transformation, no significant dose rate effect was seen. A plot of transformation

  12. Effect of radiofrequency radiation in cultured mammalian cells: A review.

    Science.gov (United States)

    Manna, Debashri; Ghosh, Rita

    2016-01-01

    The use of mobile phone related technologies will continue to increase in the foreseeable future worldwide. This has drawn attention to the probable interaction of radiofrequency electromagnetic radiation with different biological targets. Studies have been conducted on various organisms to evaluate the alleged ill-effect on health. We have therefore attempted to review those work limited to in vitro cultured cells where irradiation conditions were well controlled. Different investigators have studied varied endpoints like DNA damage, cell cycle arrest, reactive oxygen species (ROS) formation, cellular morphology and viability to weigh the genotoxic effect of such radiation by utilizing different frequencies and dose rates under various irradiation conditions that include continuous or pulsed exposures and also amplitude- or frequency-modulated waves. Cells adapt to change in their intra and extracellular environment from different chemical and physical stimuli through organized alterations in gene or protein expression that result in the induction of stress responses. Many studies have focused on such effects for risk estimations. Though the effects of microwave radiation on cells are often not pronounced, some investigators have therefore combined radiofrequency radiation with other physical or chemical agents to observe whether the effects of such agents were augmented or not. Such reports in cultured cellular systems have also included in this review. The findings from different workers have revealed that, effects were dependent on cell type and the endpoint selection. However, contradictory findings were also observed in same cell types with same assay, in such cases the specific absorption rate (SAR) values were significant.

  13. Radiation Changes the Metabolic Profiling of Melanoma Cell Line B16

    Science.gov (United States)

    Yu, Yating; Liang, Wei; Zheng, Qinghui; Huang, Xianing; Huang, Yong; Lu, Xiaoling; Zhao, Yongxiang

    2016-01-01

    Radiation therapy can be an effective way to kill cancer cells using ionizing radiation, but some tumors are resistant to radiation therapy and the underlying mechanism still remains elusive. It is therefore necessary to establish an appropriate working model to study and monitor radiation-mediated cancer therapy. In response to cellular stress, the metabolome is the integrated profiling of changes in all metabolites in cells, which can be used to investigate radiation tolerance mechanisms and identify targets for cancer radiation sensibilization. In this study, using 1H nuclear magnetic resonance for untargeted metabolic profiling in radiation-tolerant mouse melanoma cell line B16, we comprehensively investigated changes in metabolites and metabolic network in B16 cells in response to radiation. Principal component analysis and partial least squares discriminant analysis indicated the difference in cellular metabolites between the untreated cells and X-ray radiated cells. In radiated cells, the content of alanine, glutamate, glycine and choline was increased, while the content of leucine, lactate, creatine and creatine phosphate was decreased. Enrichment analysis of metabolic pathway showed that the changes in metabolites were related to multiple metabolic pathways including the metabolism of glycine, arginine, taurine, glycolysis, and gluconeogenesis. Taken together, with cellular metabolome study followed by bioinformatic analysis to profile specific metabolic pathways in response to radiation, we deepened our understanding of radiation-resistant mechanisms and radiation sensibilization in cancer, which may further provide a theoretical and practical basis for personalized cancer therapy. PMID:27631970

  14. Learning LM Specificity for Ganglion Cells

    Science.gov (United States)

    Ahumada, Albert J.

    2015-01-01

    Unsupervised learning models have been proposed based on experience (Ahumada and Mulligan, 1990;Wachtler, Doi, Lee and Sejnowski, 2007) that allow the cortex to develop units with LM specific color opponent receptive fields like the blob cells reported by Hubel and Wiesel on the basis of visual experience. These models used ganglion cells with LM indiscriminate wiring as inputs to the learning mechanism, which was presumed to occur at the cortical level.

  15. Radiation response of human hematopoietic cells

    International Nuclear Information System (INIS)

    The radiosensitivity and capacity to accumulate and repair sub-lethal damage has been studied in hematopoietic cell lines of human origin and in stem cells derived from blood and bone narrow of normal human donors. The results were analysed in terms of the linear quadratic and multitarget models. For the cell lines intrinsic radiosensitivity varied widely with D/sub o/'s ranging from 0.53 to 1.39 Gy. Five of the cell lines showed same capacity to accumulate sub-lethal damage and in three of these survival was enhanced by dose fractionation or reduction of dose rate. Among the cell lines of leukemic origin, several did not conform in one or more respects with the highly radiosensitive and repair deficient model associated with hematopoietic cells. There was no apparent correlation between radiation response and the phenotype (myeloid, lymphoid or undifferentiated) of the cell lines studied. Variability of radiation response and in some cases an unpredicted degree of radioresistance and capacity to repair sub-lethal damage has now been demonstrated for both cultured and primary explants of human leukemic cells. These observations have implications for the design of Total Body Irradiation protocols for use prior to bone narrow transplant

  16. Design Specifications for a Radiation Tolerant Beam Loss Measurement ASIC

    CERN Document Server

    Venturini, G G; Effinger, E; Zamantzas, C

    2009-01-01

    A novel radiation-hardened current digitizer ASIC is in planning stage, aimed at the acquisition of the current signals from the ionization chambers employed in the Beam Loss Monitoring system at CERN. The purpose is to match and exceed the performance of the existing discrete component design, currently in operation in the Large Hadron Collider (LHC). The specifications include: a dynamic range of nine decades, defaulting to the 1 pA-1mA range but adjustable by the user, ability to withstand a total integrated dose of 10 kGy at least in 20 years of operation and user selectable integrating windows, as low as 500 ns. Moreover, the integrated circuit should be able to digitize currents of both polarity with a minimum number of external components and without needing any configuration. The target technology is the IBM 130nm CMOS process. The specifications, the architecture choices and the reasons on which they are based upon are discussed in this paper.

  17. Embryonic stem cell neurogenesis and neural specification.

    Science.gov (United States)

    Germain, Noélle; Banda, Erin; Grabel, Laura

    2010-10-15

    The prospect of using embryonic stem cell (ESC)-derived neural progenitors and neurons to treat neurological disorders has led to great interest in defining the conditions that guide the differentiation of ESCs, and more recently induced pluripotent stem cells (iPSCs), into neural stem cells (NSCs) and a variety of neuronal and glial subtypes. Over the past decade, researchers have looked to the embryo to guide these studies, applying what we know about the signaling events that direct neural specification during development. This has led to the design of a number of protocols that successfully promote ESC neurogenesis, terminating with the production of neurons and glia with diverse regional addresses and functional properties. These protocols demonstrate that ESCs undergo neural specification in two, three, and four dimensions, mimicking the cell-cell interactions, patterning, and timing that characterizes the in vivo process. We therefore propose that these in vitro systems can be used to examine the molecular regulation of neural specification. PMID:20589755

  18. Cell-Specific Aptamers as Emerging Therapeutics

    Directory of Open Access Journals (Sweden)

    Cindy Meyer

    2011-01-01

    Full Text Available Aptamers are short nucleic acids that bind to defined targets with high affinity and specificity. The first aptamers have been selected about two decades ago by an in vitro process named SELEX (systematic evolution of ligands by exponential enrichment. Since then, numerous aptamers with specificities for a variety of targets from small molecules to proteins or even whole cells have been selected. Their applications range from biosensing and diagnostics to therapy and target-oriented drug delivery. More recently, selections using complex targets such as live cells have become feasible. This paper summarizes progress in cell-SELEX techniques and highlights recent developments, particularly in the field of medically relevant aptamers with a focus on therapeutic and drug-delivery applications.

  19. Specific features of electron radiation in ondulators with intense fields

    International Nuclear Information System (INIS)

    Ondulator radiation properties in a great-amplitude sign-variable magnetic field have been analytically analyzed. A difference is considered between spectral-angular and polarization characteristics of electron radiation in the ondulator and corresponding characteristics of electron radiaiton in storage-ring bending magnets. Discussed also is the radiation in the frequency range with the radiation maximum for fields near to the optimal one in the plane passing through the ondulator axis and normal to the particle oscillation plane

  20. Radiation therapy for intracranial germ cell tumors

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Shingo; Hayakawa, Kazushige; Tsuchiya, Miwako; Arai, Masahiko; Kazumoto, Tomoko; Niibe, Hideo; Tamura, Masaru

    1988-04-01

    The results of radiation therapy in 31 patients with intracranial germ cell tumors have been analyzed. The five-year survival rates were 70.1 % for germinomas and 38.1 % for teratomas. Three patients with germinoma have since died of spinal seeding. The prophylactic irradiation of the spinal canal has been found effective in protecting spinal seeding, since no relapse of germinoma has been observed in cases that received entire neuraxis iradiation, whereas teratomas and marker (AFP, HCG) positive tumors did not respond favorably to radiation therapy, and the cause of death in these patients has been local failure. Long-term survivors over 3 years after radiation therapy have been determined as having a good quality of life.

  1. Cell Specific eQTL Analysis without Sorting Cells.

    Directory of Open Access Journals (Sweden)

    Harm-Jan Westra

    2015-05-01

    Full Text Available The functional consequences of trait associated SNPs are often investigated using expression quantitative trait locus (eQTL mapping. While trait-associated variants may operate in a cell-type specific manner, eQTL datasets for such cell-types may not always be available. We performed a genome-environment interaction (GxE meta-analysis on data from 5,683 samples to infer the cell type specificity of whole blood cis-eQTLs. We demonstrate that this method is able to predict neutrophil and lymphocyte specific cis-eQTLs and replicate these predictions in independent cell-type specific datasets. Finally, we show that SNPs associated with Crohn's disease preferentially affect gene expression within neutrophils, including the archetypal NOD2 locus.

  2. Cell Specific eQTL Analysis without Sorting Cells

    NARCIS (Netherlands)

    Westra, Harm-Jan; Arends, Danny; Esko, Tonu; Peters, Marjolein J.; Schurmann, Claudia; Schramm, Katharina; Kettunen, Johannes; Yaghootkar, Hanieh; Fairfax, Benjamin P.; Andiappan, Anand Kumar; Li, Yang; Fu, Jingyuan; Karjalainen, Juha; Platteel, Mathieu; Visschedijk, Marijn; Weersma, Rinse K.; Kasela, Silva; Milani, Lili; Tserel, Liina; Peterson, Part; Reinmaa, Eva; Hofman, Albert; Uitterlinden, Andre G.; Rivadeneira, Fernando; Homuth, Georg; Petersmann, Astrid; Lorbeer, Roberto; Prokisch, Holger; Meitinger, Thomas; Herder, Christian; Roden, Michael; Grallert, Harald; Ripatti, Samuli; Perola, Markus; Wood, Andrew R.; Melzer, David; Ferrucci, Luigi; Singleton, Andrew B.; Hernandez, Dena G.; Knight, Julian C.; Melchiotti, Rossella; Lee, Bernett; Poidinger, Michael; Zolezzi, Francesca; Larbi, Anis; Wang, De Yun; van den Berg, Leonard H.; Veldink, Jan H.; Rotzschke, Olaf; Makino, Seiko; Salomaa, Veikko; Strauch, Konstantin; Voelker, Uwe; van Meurs, Joyce B. J.; Metspalu, Andres; Wijmenga, Cisca; Jansen, Ritsert C.; Franke, Lude

    2015-01-01

    The functional consequences of trait associated SNPs are often investigated using expression quantitative trait locus (eQTL) mapping. While trait-associated variants may operate in a cell-type specific manner, eQTL datasets for such cell-types may not always be available. We performed a genome-envir

  3. Cell Specific eQTL Analysis without Sorting Cells

    NARCIS (Netherlands)

    H.J. Westra (Harm-Jan); D. Arends (Danny); T. Esko (Tõnu); M.J. Peters (Marjolein); C. Schurmann (Claudia); K. Schramm (Katharina); J. Kettunen (Johannes); H. Yaghootkar (Hanieh); B.P. Fairfax (Benjamin); A.K. Andiappan (Anand Kumar); Y. Li (Yang); J. Fu (Jingyuan); J. Karjalainen (Juha); I. Platteel (Inge); M. Visschedijk (Marijn); R.K. Weersma (Rinse K.); S. Kasela (Silva); L. Milani (Lili); L. Tserel (Liina); P. Peterson (Pärt); E. Reinmaa (Eva); A. Hofman (Albert); A.G. Uitterlinden (André); F. Rivadeneira Ramirez (Fernando); G. Homuth (Georg); A. Petersmann (Astrid); R. Lorbeer (Roberto); H. Prokisch (Holger); T. Meitinger (Thomas); C. Herder (Christian); M. Roden (Michael); H. Grallert (Harald); S. Ripatti (Samuli); M. Perola (Markus); A.R. Wood (Andrew); D. Melzer (David); L. Ferrucci (Luigi); A. Singleton (Andrew); D.G. Hernandez (Dena); J.C. Knight (Julian); R. Melchiotti (Rossella); B. Lee (Bernett); M. Poidinger (Michael); F. Zolezzi (Francesca); A. Larbi (Anis); D.Y. Wang (De Yun); L.H. van den Berg (Leonard); J.H. Veldink (Jan); O. Rotzschke (Olaf); S. Makino (Seiko); V. Salomaa (Veikko); K. Strauch (Konstantin); U. Völker (Uwe); J.B.J. van Meurs (Joyce); A. Metspalu (Andres); C. Wijmenga (Cisca); R.C. Jansen (Ritsert); L. Franke (Lude)

    2015-01-01

    textabstractThe functional consequences of trait associated SNPs are often investigated using expression quantitative trait locus (eQTL) mapping. While trait-associated variants may operate in a cell-type specific manner, eQTL datasets for such cell-types may not always be available. We performed a

  4. Cancer stem cells, cancer cell plasticity and radiation therapy.

    Science.gov (United States)

    Vlashi, Erina; Pajonk, Frank

    2015-04-01

    Since the first prospective identification of cancer stem cells in solid cancers the cancer stem cell hypothesis has reemerged as a research topic of increasing interest. It postulates that solid cancers are organized hierarchically with a small number of cancer stem cells driving tumor growth, repopulation after injury and metastasis. They give rise to differentiated progeny, which lack these features. The model predicts that for any therapy to provide cure, all cancer stem cells have to be eliminated while the survival of differentiated progeny is less critical. In this review we discuss recent reports challenging the idea of a unidirectional differentiation of cancer cells. These reports provide evidence supporting the idea that non-stem cancer cells exhibit a remarkable degree of plasticity that allows them to re-acquire cancer stem cell traits, especially in the context of radiation therapy. We summarize conditions under which differentiation is reversed and discuss the current knowledge of the underlying mechanisms.

  5. Cell/Tissue Culture Radiation Exposure Facility Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a Cell/Tissue Culture Radiation Exposure Facility (CTC-REF) to enable radiobiologists to investigate the real-time radiation effects on...

  6. Cell-Specific Cre Strains For Genetic Manipulation in Salivary Glands.

    Directory of Open Access Journals (Sweden)

    Eri O Maruyama

    Full Text Available The secretory acinar cells of the salivary gland are essential for saliva secretion, but are also the cell type preferentially lost following radiation treatment for head and neck cancer. The source of replacement acinar cells is currently a matter of debate. There is evidence for the presence of adult stem cells located within specific ductal regions of the salivary glands, but our laboratory recently demonstrated that differentiated acinar cells are maintained without significant stem cell contribution. To enable further investigation of salivary gland cell lineages and their origins, we generated three cell-specific Cre driver mouse strains. For genetic manipulation in acinar cells, an inducible Cre recombinase (Cre-ER was targeted to the prolactin-induced protein (Pip gene locus. Targeting of the Dcpp1 gene, encoding demilune cell and parotid protein, labels intercalated duct cells, a putative site of salivary gland stem cells, and serous demilune cells of the sublingual gland. Duct cell-specific Cre expression was attempted by targeting the inducible Cre to the Tcfcp2l1 gene locus. Using the R26Tomato Red reporter mouse, we demonstrate that these strains direct inducible, cell-specific expression. Genetic tracing of acinar cells using PipGCE supports the recent finding that differentiated acinar cells clonally expand. Moreover, tracing of intercalated duct cells expressing DcppGCE confirms evidence of duct cell proliferation, but further analysis is required to establish that renewal of secretory acinar cells is dependent on stem cells within these ducts.

  7. Cell-Specific Cre Strains For Genetic Manipulation in Salivary Glands.

    Science.gov (United States)

    Maruyama, Eri O; Aure, Marit H; Xie, Xiaoling; Myal, Yvonne; Gan, Lin; Ovitt, Catherine E

    2016-01-01

    The secretory acinar cells of the salivary gland are essential for saliva secretion, but are also the cell type preferentially lost following radiation treatment for head and neck cancer. The source of replacement acinar cells is currently a matter of debate. There is evidence for the presence of adult stem cells located within specific ductal regions of the salivary glands, but our laboratory recently demonstrated that differentiated acinar cells are maintained without significant stem cell contribution. To enable further investigation of salivary gland cell lineages and their origins, we generated three cell-specific Cre driver mouse strains. For genetic manipulation in acinar cells, an inducible Cre recombinase (Cre-ER) was targeted to the prolactin-induced protein (Pip) gene locus. Targeting of the Dcpp1 gene, encoding demilune cell and parotid protein, labels intercalated duct cells, a putative site of salivary gland stem cells, and serous demilune cells of the sublingual gland. Duct cell-specific Cre expression was attempted by targeting the inducible Cre to the Tcfcp2l1 gene locus. Using the R26Tomato Red reporter mouse, we demonstrate that these strains direct inducible, cell-specific expression. Genetic tracing of acinar cells using PipGCE supports the recent finding that differentiated acinar cells clonally expand. Moreover, tracing of intercalated duct cells expressing DcppGCE confirms evidence of duct cell proliferation, but further analysis is required to establish that renewal of secretory acinar cells is dependent on stem cells within these ducts.

  8. Probabilities of Radiation Myelopathy Specific to Stereotactic Body Radiation Therapy to Guide Safe Practice

    Energy Technology Data Exchange (ETDEWEB)

    Sahgal, Arjun, E-mail: arjun.sahgal@rmp.uhn.on.ca [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, ON (Canada); Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON (Canada); Weinberg, Vivian [University of California San Francisco Helen Diller Family Comprehensive Cancer Center Biostatistics Core, San Francisco, California (United States); Ma, Lijun [Department of Radiation Oncology, University of California at San Francisco, San Francisco, California (United States); Chang, Eric [Department of Radiation Oncology, University of Southern California and University of Texas MD Anderson Cancer Center, University of Texas, Houston, Texas (United States); Chao, Sam [Department of Radiation Oncology and Neurosurgery, Cleveland Clinic, Cleveland, Ohio (United States); Muacevic, Alexander [European Cyberknife Center Munich in affiliation with University Hospitals of Munich, Munich (Germany); Gorgulho, Alessandra [Department of Neurosurgery, University of California at Los Angeles, Los Angeles, California (United States); Soltys, Scott [Department of Radiation Oncology, Stanford University, Stanford, California (United States); Gerszten, Peter C. [Departments of Neurological Surgery and Radiation Oncology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (United States); Ryu, Sam [Department of Radiation Oncology, Henry Ford Hospital, Detroit, Michigan (United States); Angelov, Lilyana [Department of Radiation Oncology and Neurosurgery, Cleveland Clinic, Cleveland, Ohio (United States); Gibbs, Iris [Department of Radiation Oncology, Stanford University, Stanford, California (United States); Wong, C. Shun [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON (Canada); Larson, David A. [Department of Radiation Oncology, University of California at San Francisco, San Francisco, California (United States)

    2013-02-01

    Purpose: Dose-volume histogram (DVH) results for 9 cases of post spine stereotactic body radiation therapy (SBRT) radiation myelopathy (RM) are reported and compared with a cohort of 66 spine SBRT patients without RM. Methods and Materials: DVH data were centrally analyzed according to the thecal sac point maximum (Pmax) volume, 0.1- to 1-cc volumes in increments of 0.1 cc, and to the 2 cc volume. 2-Gy biologically equivalent doses (nBED) were calculated using an {alpha}/{beta} = 2 Gy (units = Gy{sub 2/2}). For the 2 cohorts, the nBED means and distributions were compared using the t test and Mann-Whitney test, respectively. Significance (P<.05) was defined as concordance of both tests at each specified volume. A logistic regression model was developed to estimate the probability of RM using the dose distribution for a given volume. Results: Significant differences in both the means and distributions at the Pmax and up to the 0.8-cc volume were observed. Concordant significance was greatest for the Pmax volume. At the Pmax volume the fit of the logistic regression model, summarized by the area under the curve, was 0.87. A risk of RM of 5% or less was observed when limiting the thecal sac Pmax volume doses to 12.4 Gy in a single fraction, 17.0 Gy in 2 fractions, 20.3 Gy in 3 fractions, 23.0 Gy in 4 fractions, and 25.3 Gy in 5 fractions. Conclusion: We report the first logistic regression model yielding estimates for the probability of human RM specific to SBRT.

  9. Radiolabeled blood cells: radiation dosimetry and significance

    International Nuclear Information System (INIS)

    Over the past few years blood cells labeled with In-111 have become increasingly useful in clinical diagnosis and biomedical research. Indium-111 by the virtue of its physical characteristics and ability to bind to cell cytoplasmic components, provides an excellent cell tracer and thereby, allows investigators to monitor in vivo cell distribution by external imaging and help determine a course of regimen in treating life threatening diseases. Due to natural phenomena such as margination, blood pool, and reticuloendothelial cell activity, in the normal state, depending upon the cell type and the quality of cell preparations, 30%-50% of the administered radioactivity is immediately distributed in the liver, spleen and bone marrow. Over a period of time the radioactivity in these organs slightly increases and decays with a physical half-life of In-111. The resulting radiation dose to these organs ranges between 1-25 rads/mCi In-111 administered. The authors have developed a new In-111 labeling technique which preserves platelet ultrastructure and shown that human lymphocytes labeled with In-111 in mixed leukocytes preparations a) are only 0.003% of the total -body lymphocytes population and b) are killed. The consequence if any may be considered insignificant, particularly because 5.6% metaphases from normal men and 6.5% metaphases from normal women in the US have at least one chromosome aberration. Calculations have shown that the risk of fatal hematological malignancy, over a 30 year period, in recipients of 100 million lymphocytes labeled with 100 μCi In-111 is 1/million patients studied. This risk is less than 0.025% of the 1981 spontaneous cancer patient rate in the country. 32 references, 10 tables

  10. Radiation Safety in Industrial Radiography. Specific Safety Guide (Spanish Edition)

    International Nuclear Information System (INIS)

    This Safety Guide provides recommendations for ensuring radiation safety in industrial radiography used in non-destructive testing. This includes industrial radiography work that utilizes X ray and gamma sources, both in shielded facilities that have effective engineering controls and in outside shielded facilities using mobile sources. Contents: 1. Introduction; 2. Duties and responsibilities; 3. Safety assessment; 4. Radiation protection programme; 5. Training and qualification; 6. Individual monitoring of workers; 7. Workplace monitoring; 8. Control of radioactive sources; 9. Safety of industrial radiography sources and exposure devices; 10. Radiography in shielded enclosures; 11. Site radiography; 12. Transport of radioactive sources; 13. Emergency preparedness and response; Appendix: IAEA categorization of radioactive sources; Annex I: Example safety assessment; Annex II: Overview of industrial radiography sources and equipment; Annex III: Examples of accidents in industrial radiography

  11. Cell to Cell Variability of Radiation-Induced Foci: Relation between Observed Damage and Energy Deposition.

    Directory of Open Access Journals (Sweden)

    Gaëtan Gruel

    Full Text Available Most studies that aim to understand the interactions between different types of photon radiation and cellular DNA assume homogeneous cell irradiation, with all cells receiving the same amount of energy. The level of DNA damage is therefore generally determined by averaging it over the entire population of exposed cells. However, evaluating the molecular consequences of a stochastic phenomenon such as energy deposition of ionizing radiation by measuring only an average effect may not be sufficient for understanding some aspects of the cellular response to this radiation. The variance among the cells associated with this average effect may also be important for the behaviour of irradiated tissue. In this study, we accurately estimated the distribution of the number of radiation-induced γH2AX foci (RIF per cell nucleus in a large population of endothelial cells exposed to 3 macroscopic doses of gamma rays from 60Co. The number of RIF varied significantly and reproducibly from cell to cell, with its relative standard deviation ranging from 36% to 18% depending on the macroscopic dose delivered. Interestingly, this relative cell-to-cell variability increased as the dose decreased, contrary to the mean RIF count per cell. This result shows that the dose effect, in terms of the number of DNA lesions indicated by RIF is not as simple as a purely proportional relation in which relative SD is constant with dose. To analyse the origins of this observed variability, we calculated the spread of the specific energy distribution for the different target volumes and subvolumes in which RIF can be generated. Variances, standard deviations and relative standard deviations all changed similarly from dose to dose for biological and calculated microdosimetric values. This similarity is an important argument that supports the hypothesis of the conservation of the association between the number of RIF per nucleus and the specific energy per DNA molecule. This

  12. Mechanisms of radiation-induced neoplastic cell transformation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, T.C.H.; Tobias, C.A.

    1984-04-01

    Studies with cultured mammalian cells demonstrated clearly that radiation can transform cells directly and can enhance the cell transformation by oncogenic DNA viruses. In general, high-LET heavy-ion radiation can be more effective than X and gamma rays in inducing neoplastic cell transformation. Various experimental results indicate that radiation-induced DNA damage, most likely double-strand breaks, is important for both the initiation of cell transformation and for the enhancement of viral transformation. Some of the transformation and enhancement lesions can be repaired properly in the cell, and the amount of irrepairable lesions produced by a given dose depends on the quality of radiation. An inhibition of repair processes with chemical agents can increase the transformation frequency of cells exposed to radiation and/or oncogenic viruses, suggesting that repair mechanisms may play an important role in the radiation transformation. The progression of radiation-transformed cells appears to be a long and complicated process that can be modulated by some nonmutagenic chemical agents, e.g., DMSO. Normal cells can inhibit the expression of transforming properties of tumorigenic cells through an as yet unknown mechanism. The progression and expression of transformation may involve some epigenetic changes in the irradiated cells. 38 references, 15 figures, 1 table.

  13. Radiation Therapy for Cutaneous T-Cell Lymphomas.

    Science.gov (United States)

    Tandberg, Daniel J; Craciunescu, Oana; Kelsey, Chris R

    2015-10-01

    Radiation therapy is an extraordinarily effective skin-directed therapy for cutaneous T-cell lymphomas. Lymphocytes are extremely sensitive to radiation and a complete response is generally achieved even with low doses. Radiation therapy has several important roles in the management of mycosis fungoides. For the rare patient with unilesional disease, radiation therapy alone is potentially curative. For patients with more advanced cutaneous disease, radiation therapy to local lesions or to the entire skin can effectively palliate symptomatic disease and provide local disease control. Compared with other skin-directed therapies, radiation therapy is particularly advantageous because it can effectively penetrate and treat thicker plaques and tumors. PMID:26433843

  14. Radiation damage and repair in cells and cell components. Part 2. Physical radiations and biological significance. Final report

    International Nuclear Information System (INIS)

    The report comprises a teaching text, encompassing all physical radiations likely to be of biological interest, and the relevant biological effects and their significance. Topics include human radiobiology, delayed effects, radiation absorption in organisms, aqueous radiation chemistry, cell radiobiology, mutagenesis, and photobiology

  15. Radiation-induced apoptosis in microvascular endothelial cells.

    OpenAIRE

    Langley, R. E.; Bump, E A; Quartuccio, S. G.; Medeiros, D.; Braunhut, S. J.

    1997-01-01

    The response of the microvasculature to ionizing radiation is thought to be an important factor in the overall response of both normal tissues and tumours. It has recently been reported that basic fibroblast growth factor (bFGF), a potent mitogen for endothelial cells, protects large vessel endothelial cells from radiation-induced apoptosis in vitro. Microvessel cells are phenotypically distinct from large vessel cells. We studied the apoptotic response of confluent monolayers of capillary en...

  16. Radiation Hybrid Mapping of the Species Cytoplasm-Specific (scsae) Gene in Wheat

    OpenAIRE

    Hossain, Khwaja G.; Riera-Lizarazu, Oscar; Kalavacharla, Venugopal; Vales, M. Isabel; Maan, Schivcharan S.; Kianian, Shahryar F

    2004-01-01

    Radiation hybrid (RH) mapping is based on radiation-induced chromosome breakage and analysis of chromosome segment retention or loss using molecular markers. In durum wheat (Triticum turgidum L., AABB), an alloplasmic durum line [(lo) durum] has been identified with chromosome 1D of T. aestivum L. (AABBDD) carrying the species cytoplasm-specific (scsae) gene. The chromosome 1D of this line segregates as a whole without recombination, precluding the use of conventional genome mapping. A radiat...

  17. Training requirements for persons with specific radiation safety roles defined in United Kingdom legislation

    International Nuclear Information System (INIS)

    This article describes the respective roles of key persons who have specific responsibilities under United Kingdom (UK) legislation for ensuring that work with sources of ionising radiation is undertaken safely. It also considers the training requirements for these people and how they are typically addressed. Particular focus is placed on the roles of persons who directly supervise work with ionising radiation and the qualified experts who provide advice on radiation protection legislation and safety requirements. (orig.)

  18. Space solar cells - High efficiency and radiation damage

    Science.gov (United States)

    Brandhorst, H. W., Jr.; Bernatowicz, D. T.

    1980-01-01

    The proceedings of the Third Solar Cell High Efficiency and Radiation Damage Meeting are outlined. The topics covered included high efficiency silicon solar cells, silicon solar cell radiation damage, GaAs solar cell performance, and 30 percent conversion devices. The study of radiation damage from a fundamental defect-centered basis is discussed and evaluated as a focus of future work. 18% AM0 efficiency and 0.7 V open-circuit voltages are designated as achievable goals for silicon solar cells, and the potential for 30% AM0 efficiencies from monolithic tandem cell designs without sunlight concentration is noted. In addition to its potential for 20% AM0 efficiencies, the GaAs cell offers the possibility of a radiation-insensitive power supply when operated at temperatures near 200 C.

  19. Occurrence of BOOP outside radiation field after radiation therapy for small cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hamanishi, Tohru; Oida, Kazukiyo [Tenri Hospital, Nara (Japan); Morimatu, Takafumi (and others)

    2001-09-01

    We report a case of bronchiolitis obliterans organizing pneumonia (BOOP) that occurred outside the radiation field after radiation therapy for small cell lung cancer. A 74-year-old woman received chemotherapy and a total of 60 Gy of radiation therapy to the right hilum and mediastinum for small cell carcinoma of the suprahilar area of the right lung. Radiation pneumonitis developed within the radiation port 3 months after the completion of radiation therapy. She complained of cough and was admitted 7 months after completion of the radiation therapy. Chest radiography and computed tomography demonstrated peripheral alveolar opacities outside the radiation field on the side contralateral to that receiving the radiation therapy. Bronchoalveolar lavage showed that the total cell count was increased, with a markedly increased percentage of lymphocytes. Transbronchial lung biopsy revealed a histologic pattern consistent with BOOP. Treatment with corticosteroids resulted in rapid improvement of the symptoms and complete resolution of the radiographic abnormalities of the left lung. Although some cases of BOOP following radiation therapy for breast cancer have been reported, none of BOOP after radiation therapy for lung cancer have appeared in the literature. (author)

  20. Cell-Specific Promoters Enable Lipid-Based Nanoparticles to Deliver Genes to Specific Cells of the Retina In Vivo.

    Science.gov (United States)

    Wang, Yuhong; Rajala, Ammaji; Cao, Binrui; Ranjo-Bishop, Michelle; Agbaga, Martin-Paul; Mao, Chuanbin; Rajala, Raju V S

    2016-01-01

    Non-viral vectors, such as lipid-based nanoparticles (liposome-protamine-DNA complex [LPD]), could be used to deliver a functional gene to the retina to correct visual function and treat blindness. However, one of the limitations of LPD is the lack of cell specificity, as the retina is composed of seven types of cells. If the same gene is expressed in multiple cell types or is absent from one desired cell type, LPD-mediated gene delivery to every cell may have off-target effects. To circumvent this problem, we have tested LPD-mediated gene delivery using various generalized, modified, and retinal cell-specific promoters. We achieved retinal pigment epithelium cell specificity with vitelliform macular dystrophy (VMD2), rod cell specificity with mouse rhodopsin, cone cell specificity with red/green opsin, and ganglion cell specificity with thymocyte antigen promoters. Here we show for the first time that cell-specific promoters enable lipid-based nanoparticles to deliver genes to specific cells of the retina in vivo. This work will inspire investigators in the field of lipid nanotechnology to couple cell-specific promoters to drive expression in a cell- and tissue-specific manner.

  1. Radiation induced secretion of surfactant from cell cultures of type II pneumocytes: an in vitro model of radiation toxicity

    International Nuclear Information System (INIS)

    The pathogenesis of pneumonitis and fibrosis secondary to lung irradiation is incompletely understood. The role of the type II alveolar epithelial pneumocyte in these processes has been under investigation. The type II pneumocyte has been shown in vivo to respond to radiation induced injury with release of pulmonary surfactant. The effect of irradiation on cell cultures of type II pneumocytes was studied to determine if this could be reproduced in vitro. Type II pneumocytes were found to release surfactant material with a threshold of radiation dose between 1000 and 1500 rad. This is similar to the dosage range over which the same effect has been demonstrated in vivo. Experimental results support the concept that the release of surfactant is not due to either cell disruption or non-specific release of phospholipid from cell membranes. Irradiation appears to trigger membrane receptor mediated surfactant release. In addition, irradiation abolishes the ability of cells to subsequently respond to a physiologic agonist, suggesting radiation induced damage to the secretory mechanism. These studies establish that surfactant release in response to irradiation in vivo is a direct effect on type II pneumocytes. Cell cultures of type II pneumocytes can serve as a laboratory model of lung cell radiation toxicity

  2. Effects of radiation and chemical substances on cells and organism

    International Nuclear Information System (INIS)

    The book treats the radiation chemistry part of biophysics and applied biophysics in the sphere of ionizing radiation. Discussed are the concepts of radiation units and radioactivity units and the relative biological efficiency. The effects of ionizing and UV radiations are analyzed at the level of macromolecular changes. Chapters dealing with genetic radiation effects discuss the effects at the cellular level with respect to cell proliferation. All these problems are used to illustrate the effect on the organism as a whole. The chapters on applied biophysics deal with the indications of radiation and chemical damage, sensitivity of cells and the organism, and the study and influencing of growth at the cellular level. The concluding chapter is devoted to the environmental impact of radiation. (J.P.)

  3. Stem cell-based therapies for acute radiation syndrome

    International Nuclear Information System (INIS)

    Exposure to high doses of ionizing radiation in the event of accidental or intentional incident such as nuclear/radiological terrorism can lead to debilitating injuries to multiple organs resulting in death within days depending on the amount of radiation dose and the quality of radiation. Unfortunately, there is not a single FDA-licensed drug approved against acute radiation injury. The RadStem Center for Medical Countermeasures against Radiation (RadStem CMGR) program at Einstein is developing stem cell-based therapies to treat acute radiation syndrome (ARS). We have demonstrated that intravenous transplantation of bone marrow-derived and adipose-derived stromal cells, consisting of a mixture of mesenchymal, endothelial and myeloid progenitors can mitigate mice exposed to whole body irradiation of 12 Gy or whole abdominal irradiation of up to 20 Gy. We identified a variety of growth and differentiation factors that individually is unable to improve survival of animals exposed to lethal irradiation, but when administered sequentially mitigates radiation injury and improves survival. We termed this phenomenon as synthetic survival and describe a new paradigm whereby the 'synthetic survival' of irradiated tissues can be promoted by systemic administration of growth factors to amplify residual stem cell clonogens post-radiation exposure, followed by a differentiation factor that favors tissue stem cell differentiation. Synthetic survival can be applied to mitigate lethal radiation injury in multiple organs following radiation-induced hematopoeitic, gastrointestinal and pulmonary syndromes. (author)

  4. Altruistic cell suicide in relation to radiation hormesis

    International Nuclear Information System (INIS)

    The high radiosensitivity to killing of undifferentiated primordial cells (Bergonie and Tribondeau 1906) can be described as a manifestation of the suicide of injured cells for the benefit of an organism as a whole if their suicide stimulates proliferation of healthy cells to replace them, resulting in complete elimination of injury. This process is called cell-replacement repair, to distinguish it from DNA repair which is rarely complete. 'Cell suicide', 'programmed death' and 'apoptosis' are terms used for the same type of active cell death. Cell suicide is not always altruistic. Altruistic suicide in Drosophila, mice, humans, plants, and E. coli is reviewed in this paper to illustrate its widely different facets. The hypothesis that in animals, radiation hormesis results from altruistic cell suicide is proposed. This hypothesis can explain the hormetic effect of low doses of radiation on the immune system in mice. In contrast, in plants, radiation hormesis seems to be mainly due to non-altruistic cell death. (author)

  5. Survival and signaling changes in antigen presenting cell subsets after radiation

    Science.gov (United States)

    Parker, Jennifer Janell

    examine co-stimulatory receptor activation, pro-inflammatory cytokine release, and T cell proliferation with and without radiation and inhibition of the NFkappaB pathway, demonstrated that NEMO is necessary for the activation, maturation, and enhanced responsiveness of human subsets of antigen presenting cells that occur after radiation. These findings provided insight into the mechanism of action of radiation-enhanced promotion of the antigen presenting cell responses. The methods of analysis employed can be used for monitoring immune changes that impact immune modulation in transplantation and tumor vaccines studies. Furthermore, NFkappaB pathway proteins have the potential to serve as biomarkers for optimal antitumor responses. The NBD peptide may also have usefulness as a therapeutic agent for inhibition of graft versus host disease (GVHD) in patients who have undergone transplantation. While the first set of experiments focused on antigen presenting cell responsiveness, the second set of experiments were designed to enhance our understanding of why antigen presenting cells, specifically monocytes and dendritic cells, are more radioresistant than conventional T cells. Flow cytometric analysis of various surface markers and intracellular signaling markers were used to examine the mechanisms behind the radioresistance of antigen presenting cells. The experiments described here showed a hierarchy of radiosensitivity among T cells, with naive CD8 T cells being the most radiosensitive and CD4 memory T cells being the most radioresistant. Antigen presenting cells were found to be significantly more radioresistant than T cell subsets (<10 fold decrease after radiation), and among APC, monocytes were more radiosensitive than either total or conventional dendritic cells. Furthermore APC expressed lower levels of Bax after radiation than T cells, and APC subsets that expressed high levels were also more sensitive to radiation induced cell death. These results demonstrate that T

  6. Effects of ionizing radiation on bone cell differentiation in an experimental murine bone cell model

    Science.gov (United States)

    Baumstark-Khan, Christa; Lau, Patrick; Hellweg, Christine; Reitz, Guenther

    -immunostaining. Osteoblastogenesis was estimated by measurement of alkaline phosphatase (ALP) activity and production of mineralized matrix (von-Kossa staining, Alizarin Red staining). During the process of osteoblastic cell differentiation, the expression of the bone specific marker genes osteocalcin (OCN) and osteopontin (OPN) were recorded by quantitative real time reverse transcription PCR (qRT-PCR). Compared with standard culture conditions, the osteogenic marker genes OCN and OPN were highly expressed during the differentiation process induced either by osteo-inductive media additives (50 µg/ml ascorbic acid, 10 mmol/l β-glycero phosphate) or by sparsely ionizing radiation (X-rays). After 21 days of postirradiation incubation sparsely ionizing radiation could be shown to induce the formation of bone-like nodules (von-Kossa staining) for OCT-1 and MC3T3-E1 S4 cells but nor for MC3T3- E1 S24 cells. Ionizing radiation leads to a cell cycle arrest which is resolved in a dose and time dependent way. This was accompanied by a dose dependent regulation of the cyclin kinase inhibitor CDKN1A (p21/WAF) and transforming growth factor beta 1 (TGF-β1). TGF-β1 is known to affect osteoblast differentiation, matrix formation and mineralization. Modulation of its expression could influence the expression of main osteogenic transcription factors. For exposure with high LET radiation a pronounced cell cycle block was evident. The expression of the osteogenic marker genes OCN and Osterix (OSX) was increased in the OCT-1 cells with differentiation potential for exposure to α particles and accelerated carbon and argon ions. The results on the expression of differentiation markers during radiation-induced premature differentiation of bone cells of the osteoblast lineage show that densely ionizing radiation results in expression of proteins essential for bone formation and consequently in an increase in bone volume. Such an effect has been observed in in-vivo carbon ion irradiated rats. As radiation dependent

  7. p53-Dependent Adaptive Responses in Human Cells Exposed to Space Radiations

    International Nuclear Information System (INIS)

    Purpose: It has been reported that priming irradiation or conditioning irradiation with a low dose of X-rays in the range of 0.02-0.1 Gy induces a p53-dependent adaptive response in mammalian cells. The aim of the present study was to clarify the effect of space radiations on the adaptive response. Methods and Materials: Two human lymphoblastoid cell lines were used; one cell line bears a wild-type p53 (wtp53) gene, and another cell line bears a mutated p53 (mp53) gene. The cells were frozen during transportation on the space shuttle and while in orbit in the International Space Station freezer for 133 days between November 15, 2008 and March 29, 2009. After the frozen samples were returned to Earth, the cells were cultured for 6 h and then exposed to a challenging X-ray-irradiation (2 Gy). Cellular sensitivity, apoptosis, and chromosome aberrations were scored using dye-exclusion assays, Hoechst33342 staining assays, and chromosomal banding techniques, respectively. Results: In cells exposed to space radiations, adaptive responses such as the induction of radioresistance and the depression of radiation-induced apoptosis and chromosome aberrations were observed in wtp53 cells but not in mp53 cells. Conclusion: These results have confirmed the hypothesis that p53-dependent adaptive responses are apparently induced by space radiations within a specific range of low doses. The cells exhibited this effect owing to space radiations exposure, even though the doses in space were very low.

  8. Mesenchymal stem cell therapy for acute radiation syndrome.

    Science.gov (United States)

    Fukumoto, Risaku

    2016-01-01

    Acute radiation syndrome affects military personnel and civilians following the uncontrolled dispersal of radiation, such as that caused by detonation of nuclear devices and inappropriate medical treatments. Therefore, there is a growing need for medical interventions that facilitate the improved recovery of victims and patients. One promising approach may be cell therapy, which, when appropriately implemented, may facilitate recovery from whole body injuries. This editorial highlights the current knowledge regarding the use of mesenchymal stem cells for the treatment of acute radiation syndrome, the benefits and limitations of which are under investigation. Establishing successful therapies for acute radiation syndrome may require using such a therapeutic approach in addition to conventional approaches. PMID:27182446

  9. Skin Biopsy and Patient-Specific Stem Cell Lines

    Science.gov (United States)

    Li, Yao; Nguyen, Huy V.; Tsang, Stephen H.

    2016-01-01

    The generation of patient-specific induced pluripotent stem (iPS) cells permits the development of next-generation patient-specific systems biology models reflecting personalized genomics profiles to better understand pathophysiology. In this chapter, we describe how to create a patient-specific iPS cell line. There are three major steps: (1) performing a skin biopsy procedure on the patient; (2) extracting human fibroblast cells from the skin biopsy tissue; and (3) reprogramming patient-specific fibroblast cells into the pluripotent stem cell stage. PMID:26141312

  10. Quantification of circulating cell-free DNA in the plasma of cancer patients during radiation therapy

    International Nuclear Information System (INIS)

    Cell-free plasma DNA is elevated in cancer patients and decreases in response to effective treatments. Consequently, these nucleic acids have potential as new tumor markers. In our current study, we investigated whether the plasma DNA concentrations in patients with cancer are altered during the course of radiation therapy. To first determine the origin of cell-free plasma DNA, plasma samples from mice bearing transplanted human tumors were analyzed for human-specific and mouse-specific cell-free DNA. Human-specific DNA was detectable only in plasma from tumor-bearing mice. However, mouse-specific plasma DNA was significantly higher in tumor-bearing mice than in normal mice, suggesting that cell-free plasma DNA originated from both tumor and normal cells. We measured the total cell-free plasma DNA levels by quantitative polymerase chain reaction in 15 cancer patients undergoing radiation therapy and compared these values with healthy control subjects. The cancer patients showed higher pretreatment plasma DNA concentrations than the healthy controls. Eleven of these patients showed a transient increase of up to eightfold in their cell-free plasma DNA concentrations during the first or second week of radiation therapy, followed by decreasing concentrations toward the end of treatment. In two other cancer patients, the cell-free plasma DNA concentrations only decreased over the course of the treatment. The total cell-free plasma DNA levels in cancer patients thus show dynamic changes associated with the progression of radiation therapy. Additional prospective studies will be required to elucidate the potential clinical utility and biological implications of dynamic changes in cell-free plasma DNA during radiation therapy. (author)

  11. DNA repair and radiation sensitivity in mammalian cells

    International Nuclear Information System (INIS)

    Ionizing radiation induces various types of damage in mammalian cells including DNA single-strand breaks, DNA double-strand breaks (DSB), DNA-protein cross links, and altered DNA bases. Although human cells can repair many of these lesions there is little detailed knowledge of the nature of the genes and the encoded enzymes that control these repair processes. We report here on the cellular and genetic analyses of DNA double-strand break repair deficient mammalian cells. It has been well established that the DNA double-strand break is one of the major lesions induced by ionizing radiation. Utilizing rodent repair-deficient mutant, we have shown that the genes responsible for DNA double-strand break repair are also responsible for the cellular expression of radiation sensitivity. The molecular genetic analysis of DSB repair in rodent/human hybrid cells indicate that at least 6 different genes in mammalian cells are responsible for the repair of radiation-induced DNA double-strand breaks. Mapping and the prospect of cloning of human radiation repair genes are reviewed. Understanding the molecular and genetic basis of radiation sensitivity and DNA repair in man will provide a rational foundation to predict the individual risk associated with radiation exposure and to prevent radiation-induced genetic damage in the human population

  12. Enteric glial cells have specific immunosuppressive properties.

    Science.gov (United States)

    Kermarrec, Laetitia; Durand, Tony; Neunlist, Michel; Naveilhan, Philippe; Neveu, Isabelle

    2016-06-15

    Enteric glial cells (EGC) have trophic and neuroregulatory functions in the enteric nervous system, but whether they exert a direct effect on immune cells is unknown. Here, we used co-cultures to show that human EGC can inhibit the proliferation of activated T lymphocytes. Interestingly, EGC from Crohn's patients were effective at one EGC for two T cells whereas EGC from control patients required a ratio of 1:1. These data suggest that EGC contribute to local immune homeostasis in the gastrointestinal wall. They also raise the possibility that EGC have particular immunosuppressive properties in inflammatory bowel diseases such as Crohn's disease. PMID:27235353

  13. Thermal radiosensitization in radiation-sensitive mutant mouse leukemic cells

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Toshikazu (Hiroshima Univ. (Japan). School of Dentistry)

    1994-06-01

    This study investigated thermal, radiation, and combined thermal radiation sensitization of mouse leukemic cells, L5178Y, and radiation-sensitive mutant cells, LX830. Radiation sensitivity (D[sub 0]) values were 0.41 Gy for LX830 and 1.39 Gy for L5178Y, with the ratio of D[sub 0] values in LX830 to in L5178Y being 3.4. Thus, LX830 was more radiosensitive than L5178Y. LX830 showed no shouldered survival curves. Although sublethal damage (SLD) repair was seen to the almost same degree in both LX830 and L5178Y, potential lethal damage (PLD) repair was scarcely observed in LX830. Both cell lines were similar in thermal sensitivity (T[sub 0]). Eosine staining suggested that cell killing due to hyperthermia had occurred in the interphase in both LX830 and L5178Y. L5178Y showed thermal sensitivity low in the G1 phase and high in the S phase; on the contrary, LX830 showed it high in the G1 phase and low in the S phase. Thermal radiosensitization was similar in both cell lines, although there was a great difference in radiation sensitivity between the cell lines. The difference in radiation sensitivity (D[sub 0]) between L5178Y and LX830 became small when radiation was given at the time of the maximum thermal resistance. This seemed to contribute to a decrease in radiation sensitivity in LX830. It can be concluded that thermal radiosensitization depends on thermal sensitivity and that radiation sensitivity decreases in radiation-sensitive cells when exposed to irradiation at the time of thermal resistance. (N.K.).

  14. Effect of troglitazone on radiation sensitivity in cervix cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    An, Zheng Zhe; Liu, Xian Guang; Song, Hye Jin; Choi, Chi Hwan; Kim, Won Dong; Park, Woo Yoon [Chungbuk National University College of Medicine, Cheongju (Korea, Republic of); Yu, Jae Ran [Konkuk University College of Medicine, Chungju (Korea, Republic of)

    2012-06-15

    Troglitazone (TRO) is a peroxisome proliferator-activated receptor {gamma} (PPAR{gamma} ) agonist. TRO has antiproliferative activity on many kinds of cancer cells via G1 arrest. TRO also increases Cu{sup 2+}/Zn{sup 2+} -superoxide dismutase (CuZnSOD) and catalase. Cell cycle, and SOD and catalase may affect on radiation sensitivity. We investigated the effect of TRO on radiation sensitivity in cancer cells in vitro. Three human cervix cancer cell lines (HeLa, Me180, and SiHa) were used. The protein expressions of SOD and catalase, and catalase activities were measured at 2-10 {mu}M of TRO for 24 hours. Cell cycle was evaluated with flow cytometry. Reactive oxygen species (ROS) was measured using 2',7'-dichlorofluorescin diacetate. Cell survival by radiation was measured with clonogenic assay. By 5 {mu}M TRO for 24 hours, the mRNA, protein expression and activity of catalase were increased in all three cell lines. G0- G1 phase cells were increased in HeLa and Me180 by 5 {mu}M TRO for 24 hours, but those were not increased in SiHa. By pretreatment with 5 {mu}M TRO radiation sensitivity was increased in HeLa and Me180, but it was decreased in SiHa. In Me180, with 2 {mu}M TRO which increased catalase but not increased G0-G1 cells, radiosensitization was not observed. ROS produced by radiation was decreased with TRO. TRO increases radiation sensitivity through G0-G1 arrest or decreases radiation sensitivity through catalasemediated ROS scavenging according to TRO dose or cell types. The change of radiation sensitivity by combined with TRO is not dependent on the PPAR {gamma} expression level.

  15. Losartan sensitizes selectively prostate cancer cell to ionizing radiation.

    Science.gov (United States)

    Yazdannejat, H; Hosseinimehr, S J; Ghasemi, A; Pourfallah, T A; Rafiei, A

    2016-01-11

    Losartan is an angiotensin II receptor (AT-II-R) blocker that is widely used by human for blood pressure regulation. Also, it has antitumor property. In this study, we investigated the radiosensitizing effect of losartan on cellular toxicity induced by ionizing radiation on prostate cancer and non-malignant fibroblast cells. Human prostate cancer (DU-145) and human non-malignant fibroblast cells (HFFF2) were treated with losartan at different concentrations (0.5, 1, 10, 50 and 100 µM) and then these cells were exposed to ionizing radiation. The cell proliferation was determined using MTT assay. Our results showed that losartan exhibited antitumor effect on prostate cancer cells; it was reduced cell survival to 66% at concentration 1 µM. Losartan showed an additive killing effect in combination with ionizing radiation on prostate cancer cell. The cell proliferation was reduced to 54% in the prostate cancer cells treated with losartan at concentration 1 µM in combination with ionizing radiation. Losartan did not exhibit any toxicity on HFFF2 cell. This result shows a promising effect of losartan on enhancement of therapeutic effect of ionizing radiation in patients during therapy.

  16. A simple model of space radiation damage in GaAs solar cells

    Science.gov (United States)

    Wilson, J. W.; Stith, J. J.; Stock, L. V.

    1983-01-01

    A simple model is derived for the radiation damage of shallow junction gallium arsenide (GaAs) solar cells. Reasonable agreement is found between the model and specific experimental studies of radiation effects with electron and proton beams. In particular, the extreme sensitivity of the cell to protons stopping near the cell junction is predicted by the model. The equivalent fluence concept is of questionable validity for monoenergetic proton beams. Angular factors are quite important in establishing the cell sensitivity to incident particle types and energies. A fluence of isotropic incidence 1 MeV electrons (assuming infinite backing) is equivalent to four times the fluence of normal incidence 1 MeV electrons. Spectral factors common to the space radiations are considered, and cover glass thickness required to minimize the initial damage for a typical cell configuration is calculated. Rough equivalence between the geosynchronous environment and an equivalent 1 MeV electron fluence (normal incidence) is established.

  17. Measles virus-specific murine T cell clones: characterization of fine specificity function.

    NARCIS (Netherlands)

    P. de Vries (Petra); J.P.M. Versteeg-van Oosten (José); I.K.G. Visser (Ilona); R.S. van Binnendijk (Rob); S.A. Langeveld (Sacha); A.D.M.E. Osterhaus (Ab); F.G.C.M. Uytdehaag (Fons)

    1989-01-01

    textabstractMeasles virus (MV)-specific murine helper T cell clones (Thy-1.2+, CD4+, CD8-) were generated from mice immunized with MV-infected mouse brain homogenate by limiting dilution and in vitro stimulation of spleen cells with UV-inactivated MV Ag. The protein specificity of 7 out of 37 stable

  18. Stem cells in radiation and oral cancer research

    International Nuclear Information System (INIS)

    Cancer stem cells (CSCs) are defined as a small sub population of cancer cells that constitute a pool of self sustaining cells with the exclusive ability to cause the heterogeneous lineages of cancer cells that comprise the tumour. There are three main characteristics of CSCs. Initially the cell must show potent tumour initiation in that it can regenerate the tumour which it was derived from a limited number of cells. In addition, the cells should demonstrate self renewal in vivo, which is practically observed via regrowth of phenotypically indistinguishable and heterogeneous tumours following serial transplantation of re-isolated CSCs in secondary and tertiary recipients. Finally, the cells must show a differentiation capacity, allowing them to give rise to a heterogeneous progeny, which represents a phenocopy of the original tumour. This article highlights the radiation therapy resulting in radiation resistance in cancer stem cells. (author)

  19. Allergen-Specific CD4(+) T Cells in Human Asthma.

    Science.gov (United States)

    Ling, Morris F; Luster, Andrew D

    2016-03-01

    In allergic asthma, aeroallergen exposure of sensitized individuals mobilizes robust innate and adaptive airway immune responses, stimulating eosinophilic airway inflammation and the activation and infiltration of allergen-specific CD4(+) T cells into the airways. Allergen-specific CD4(+) T cells are thought to be central players in the asthmatic response as they specifically recognize the allergen and initiate and orchestrate the asthmatic inflammatory response. In this article, we briefly review the role of allergen-specific CD4(+) T cells in the pathogenesis of human allergic airway inflammation in allergic individuals, discuss the use of allergen-major histocompatibility complex class II tetramers to characterize allergen-specific CD4(+) T cells, and highlight current gaps in knowledge and directions for future research pertaining to the role of allergen-specific CD4(+) T cells in human asthma. PMID:27027948

  20. Gene expression signatures of radiation response are specific, durable and accurate in mice and humans.

    Directory of Open Access Journals (Sweden)

    Sarah K Meadows

    Full Text Available BACKGROUND: Previous work has demonstrated the potential for peripheral blood (PB gene expression profiling for the detection of disease or environmental exposures. METHODS AND FINDINGS: We have sought to determine the impact of several variables on the PB gene expression profile of an environmental exposure, ionizing radiation, and to determine the specificity of the PB signature of radiation versus other genotoxic stresses. Neither genotype differences nor the time of PB sampling caused any lessening of the accuracy of PB signatures to predict radiation exposure, but sex difference did influence the accuracy of the prediction of radiation exposure at the lowest level (50 cGy. A PB signature of sepsis was also generated and both the PB signature of radiation and the PB signature of sepsis were found to be 100% specific at distinguishing irradiated from septic animals. We also identified human PB signatures of radiation exposure and chemotherapy treatment which distinguished irradiated patients and chemotherapy-treated individuals within a heterogeneous population with accuracies of 90% and 81%, respectively. CONCLUSIONS: We conclude that PB gene expression profiles can be identified in mice and humans that are accurate in predicting medical conditions, are specific to each condition and remain highly accurate over time.

  1. Classical Radiation Reaction in Particle-In-Cell Simulations

    CERN Document Server

    Vranic, Marija; Fonseca, Ricardo A; Silva, Luis O

    2015-01-01

    Under the presence of ultra high intensity lasers or other intense electromagnetic fields the motion of particles in the ultrarelativistic regime can be severely affected by radiation reaction. The standard particle-in-cell (PIC) algorithms do not include radiation reaction effects. Even though this is a well known mechanism, there is not yet a definite algorithm nor a standard technique to include radiation reaction in PIC codes. We have compared several models for the calculation of the radiation reaction force, with the goal of implementing an algorithm for classical radiation reaction in the Osiris framework, a state-of-the-art PIC code. The results of the different models are compared with standard analytical results, and the relevance/advantages of each model are discussed. Numerical issues relevant to PIC codes such as resolution requirements, application of radiation reaction to macro particles and computational cost are also addressed. The Landau and Lifshitz reduced model is chosen for implementatio...

  2. The concept of radiation-enhanced stem cell differentiation

    Directory of Open Access Journals (Sweden)

    Mieloch Adam A.

    2015-09-01

    Full Text Available Background. Efficient stem cell differentiation is considered to be the holy grail of regenerative medicine. Pursuing the most productive method of directed differentiation has been the subject of numerous studies, resulting in the development of many effective protocols. However, the necessity for further improvement in differentiation efficiency remains. This review contains a description of molecular processes underlying the response of stem cells to ionizing radiation, indicating its potential application in differentiation procedures. In the first part, the radiation-induced damage response in various types of stem cells is described. Second, the role of the p53 protein in embryonic and adult stem cells is highlighted. Last, the hypothesis on the mitochondrial involvement in stem cell development including its response to ionizing radiation is presented.

  3. Model of cell response to {\\alpha}-particle radiation

    CERN Document Server

    Liu, Longjian

    2012-01-01

    Starting from a general equation for organism (or cell system) growth and attributing additional cell death rate (besides the natural rate) to therapy, we derive an equation for cell response to {\\alpha} radiation. Different from previous models that are based on statistical theory, the present model connects the consequence of radiation with the growth process of a biosystem and each variable or parameter has meaning regarding the cell evolving process. We apply this equation to model the dose response for {\\alpha}-particle radiation. It interprets the results of both high and low linear energy transfer (LET) radiations. When LET is high, the additional death rate is a constant, which implies that the localized cells are damaged immediately and the additional death rate is proportional to the number of cells present. While at low LET, the additional death rate includes a constant term and a linear term of radiation dose, implying that the damage to some cell nuclei has a time accumulating effect. This model ...

  4. Ionizing radiation induces PI3K-dependent JNK activation for amplifying mitochondrial dysfunction in human cervical cancer cells

    International Nuclear Information System (INIS)

    Ionizing radiation is one of the most commonly used treatments for a wide variety of tumors. Exposure of cells to ionizing radiation results in the simultaneous activation or down regulation of multiple signaling pathways, which play critical role in controlling cell death and cell survival after irradiation in a cell type specific manner. The molecular mechanism by which apoptotic cell death occurs in response to ionizing radiation has been widely explored but not precisely deciphered. Therefore an improved understanding of the mechanisms involved in radiation-induced apoptosis may ultimately provide novel strategies of intervention in specific signal transduction pathways to favorably alter the therapeutic ratio in the treatment of human malignancies. The aim of our investigation was to elucidate molecular mechanisms of the mitochondrial dysfunction mediated apoptotic cell death triggered by ionizing radiation in human cervical cancer cells. We demonstrated that ionizing radiation utilizes PI3K-JNK signaling pathway for amplifying mitochondrial dysfunction and susequent apoptotic cell death: We showed that PI3K-dependent JNK activation leads to transcriptional upregulation of Fas and the phosphorylation/inactivation of Bcl-2, resulting in mitochondrial dysfunction-mediated apoptotic cell death in response to ionizing radiation

  5. Inhibition of mTOR enhances radiosensitivity of lung cancer cells and protects normal lung cells against radiation.

    Science.gov (United States)

    Zheng, Hang; Wang, Miao; Wu, Jing; Wang, Zhi-Ming; Nan, Hai-Jun; Sun, He

    2016-06-01

    Radiotherapy has been used for a long time as a standard therapy for cancer; however, there have been no recent research breakthroughs. Radioresistance and various side-effects lead to the unexpected outcomes of radiation therapy. Specific and accurate targeting as well as reduction of radioresistance have been major challenges for irradiation therapy. Recent studies have shown that rapamycin shows promise for inhibiting tumorigenesis by suppressing mammalian target of rapamycin (mTOR). We found that the combination of rapamycin with irradiation significantly diminished cell viability and colony formation, and increased cell apoptosis, as compared with irradiation alone in lung cancer cell line A549, suggesting that rapamycin can enhance the effectiveness of radiation therapy by sensitizing cancer cells to irradiation. Importantly, we observed that the adverse effects of irradiation on a healthy lung cell line (WI-38) were also offset. No enhanced protein expression of mTOR signaling was observed in WI-38 cells, which is normally elevated in lung cancer cells. Moreover, DNA damage was significantly less with the combination therapy than with irradiation therapy alone. Our data suggest that the incorporation of rapamycin during radiation therapy could be a potent way to improve the sensitivity and effectiveness of radiation therapy as well as to protect normal cells from being damaged by irradiation. PMID:26999331

  6. Monocyte galactose/N-acetylgalactosamine-specific C-type lectin receptor stimulant immunotherapy of an experimental glioma. Part II: combination with external radiation improves survival

    International Nuclear Information System (INIS)

    A peptide mimetic of a ligand for the galactose/N-acetylgalactosamine-specific C-type lectin receptors (GCLR) exhibited monocyte-stimulating activity, but did not extend survival when applied alone against a syngeneic murine malignant glioma. In this study, the combined effect of GCLRP with radiation was investigated. C57BL/6 mice underwent stereotactic intracranial implantation of GL261 glioma cells. Animals were grouped based on randomized tumor size by magnetic resonance imaging on day seven. One group that received cranial radiation (4 Gy on days seven and nine) only were compared with animals treated with radiation and GCLRP (4 Gy on days seven and nine combined with subcutaneous injection of 1 nmol/g on alternative days beginning on day seven). Magnetic resonance imaging was used to assess tumor growth and correlated with survival rate. Blood and brain tissues were analyzed with regard to tumor and contralateral hemisphere using fluorescence-activated cell sorting analysis, histology, and enzyme-linked immunosorbent assay. GCLRP activated peripheral monocytes and was associated with increased blood precursors of dendritic cells. Mean survival increased (P < 0.001) and tumor size was smaller (P < 0.02) in the GCLRP + radiation group compared to the radiation-only group. Accumulation of dendritic cells in both the tumoral hemisphere (P < 0.005) and contralateral tumor-free hemisphere (P < 0.01) was associated with treatment. Specific populations of monocyte-derived brain cells develop critical relationships with malignant gliomas. The biological effect of GCLRP in combination with radiation may be more successful because of the damage incurred by tumor cells by radiation and the enhanced or preserved presentation of tumor cell antigens by GCLRP-activated immune cells. Monocyte-derived brain cells may be important targets for creating effective immunological modalities such as employing the receptor system described in this study

  7. Radiation related basic cancer research : research for radiation induced tumor cell killing

    International Nuclear Information System (INIS)

    The radioresistant clones was established from human U251 glioblastoma cell line through intermittently exposed to 3 Gy gamma-radiation for six months. Treatment of SNU-16 cells with various doses of radiation, TNF alpha and PMA resulted in a decrease in cell viability. The results prove that cell death of SNU16 is a apoptosis mediated by caspase-3. We have examined the expression of bcl-2 and c-myc in cervical cancer specimens and cervical intraepithelial neoplasia (CIN) to determine the role of coexpression of bcl-3 and c-myc during progression into cervical cancer. The frequent alterations in FHIT expression in many cervical carcinomas and their cell lines suggest that FHIT gene alterations are pla a role in cervical tumorigenesis. According to these correlation between the viability and apoptosis of RD cells, the proper range of the dosage for the investigation of differentiation potency in RD cells was assessed as 1 to 3Gy

  8. Radiation related basic cancer research : research for radiation induced tumor cell killing

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Hoon; Hong, Seok Il; Cho, Kyung Ja; Kim, Byung Gi; Lee, Kee Ho; Nam, Myung Jin

    1999-04-01

    The radioresistant clones was established from human U251 glioblastoma cell line through intermittently exposed to 3 Gy gamma-radiation for six months. Treatment of SNU-16 cells with various doses of radiation, TNF alpha and PMA resulted in a decrease in cell viability. The results prove that cell death of SNU16 is a apoptosis mediated by caspase-3. We have examined the expression of bcl-2 and c-myc in cervical cancer specimens and cervical intraepithelial neoplasia (CIN) to determine the role of coexpression of bcl-3 and c-myc during progression into cervical cancer. The frequent alterations in FHIT expression in many cervical carcinomas and their cell lines suggest that FHIT gene alterations are pla a role in cervical tumorigenesis. According to these correlation between the viability and apoptosis of RD cells, the proper range of the dosage for the investigation of differentiation potency in RD cells was assessed as 1 to 3Gy.

  9. Cell type-specific bipolar cell input to ganglion cells in the mouse retina.

    Science.gov (United States)

    Neumann, S; Hüser, L; Ondreka, K; Auler, N; Haverkamp, S

    2016-03-01

    Many distinct ganglion cell types, which are the output elements of the retina, were found to encode for specific features of a visual scene such as contrast, color information or movement. The detailed composition of retinal circuits leading to this tuning of retinal ganglion cells, however, is apart from some prominent examples, largely unknown. Here we aimed to investigate if ganglion cell types in the mouse retina receive selective input from specific bipolar cell types or if they sample their synaptic input non-selectively from all bipolar cell types stratifying within their dendritic tree. To address this question we took an anatomical approach and immunolabeled retinae of two transgenic mouse lines (GFP-O and JAM-B) with markers for ribbon synapses and type 2 bipolar cells. We morphologically identified all green fluorescent protein (GFP)-expressing ganglion cell types, which co-stratified with type 2 bipolar cells and assessed the total number of bipolar input synapses and the proportion of synapses deriving from type 2 bipolar cells. Only JAM-B ganglion cells received synaptic input preferentially from bipolar cell types other than type 2 bipolar cells whereas the other analyzed ganglion cell types sampled their bipolar input most likely from all bipolar cell terminals within their dendritic arbor.

  10. Roles of ionizing radiation in cell transformation

    Energy Technology Data Exchange (ETDEWEB)

    Tobias, C.A.; Albright, N.W.; Yang, T.C.

    1983-07-01

    Earlier the authors described a repair misrepair model (RMR-I) which is applicable for radiations of low LET, e.g., x rays and gamma rays. RMR-II was described later. Here is introduced a mathematical modification of the RMR model, RMR-III, which is intended to describe lethal effects caused by heavily ionizing tracks. 31 references, 4 figures.

  11. Roles of ionizing radiation in cell transformation

    International Nuclear Information System (INIS)

    Earlier the authors described a repair misrepair model (RMR-I) which is applicable for radiations of low LET, e.g., x rays and gamma rays. RMR-II was described later. Here is introduced a mathematical modification of the RMR model, RMR-III, which is intended to describe lethal effects caused by heavily ionizing tracks. 31 references, 4 figures

  12. Raman spectroscopy identifies radiation response in human non-small cell lung cancer xenografts

    Science.gov (United States)

    Harder, Samantha J.; Isabelle, Martin; Devorkin, Lindsay; Smazynski, Julian; Beckham, Wayne; Brolo, Alexandre G.; Lum, Julian J.; Jirasek, Andrew

    2016-02-01

    External beam radiation therapy is a standard form of treatment for numerous cancers. Despite this, there are no approved methods to account for patient specific radiation sensitivity. In this report, Raman spectroscopy (RS) was used to identify radiation-induced biochemical changes in human non-small cell lung cancer xenografts. Chemometric analysis revealed unique radiation-related Raman signatures that were specific to nucleic acid, lipid, protein and carbohydrate spectral features. Among these changes was a dramatic shift in the accumulation of glycogen spectral bands for doses of 5 or 15 Gy when compared to unirradiated tumours. When spatial mapping was applied in this analysis there was considerable variability as we found substantial intra- and inter-tumour heterogeneity in the distribution of glycogen and other RS spectral features. Collectively, these data provide unique insight into the biochemical response of tumours, irradiated in vivo, and demonstrate the utility of RS for detecting distinct radiobiological responses in human tumour xenografts.

  13. Solar ultraviolet radiation as a trigger of cell signal transduction

    International Nuclear Information System (INIS)

    Ultraviolet light radiation in sunlight is known to cause major alterations in growth and differentiation patterns of exposed human tissues. The specific effects depend on the wavelengths and doses of the light, and the nature of the exposed tissue. Both growth inhibition and proliferation are observed, as well as inflammation and immune suppression. Whereas in the clinical setting, these responses may be beneficial, for example, in the treatment of psoriasis and atopic dermatitis, as an environmental toxicant, ultraviolet light can induce significant tissue damage. Thus, in the eye, ultraviolet light causes cataracts, while in the skin, it induces premature aging and the development of cancer. Although ultraviolet light can damage many tissue components including membrane phospholipids, proteins, and nucleic acids, it is now recognized that many of its cellular effects are due to alterations in growth factor- and cytokine-mediated signal transduction pathways leading to aberrant gene expression. It is generally thought that reactive oxygen intermediates are mediators of some of the damage induced by ultraviolet light. Generated when ultraviolet light is absorbed by endogenous photosensitizers in the presence of molecular oxygen, reactive oxygen intermediates and their metabolites induce damage by reacting with cellular electrophiles, some of which can directly initiate cell signaling processes. In an additional layer of complexity, ultraviolet light-damaged nucleic acids initiate signaling during the activation of repair processes. Thus, mechanisms by which solar ultraviolet radiation triggers cell signal transduction are multifactorial. The present review summarizes some of the mechanisms by which ultraviolet light alters signaling pathways as well as the genes important in the beneficial and toxic effects of ultraviolet light

  14. Dominant cataract mutations and specific-locus mutations in mice induced by radiation or ethylnitrosourea

    Energy Technology Data Exchange (ETDEWEB)

    Ehling, U.H.; Favor, J.; Kratochvilova, J.; Neuhaeuser-Klaus, A. (Gesellschaft fuer Strahlen- und Umweltforschung m.b.H. Muenchen, Neuherberg (Germany, F.R.). Inst. fuer Genetik)

    1982-01-01

    In a combined experiment, dominant cataract mutations and specific-locus mutations were scored in the same offspring. In radiation experiments, a total of 15 dominant cataract and 38 specific-locus mutations was scored in 29396 offspring. In experiments with ethylnitrosourea (ENU), a total of 12 dominant cataracts and 54 specific-locus mutations was observed in 12712 offspring. The control frequency for dominant cataracts was 0 in 9954 offspring and for specific-locus mutations 11 in 169955 offspring. The two characteristic features of radiation-induced specific-locus mutations - the augmenting effect of dose fractionation and the quantitative differences in the mutation rates between spermatogonial and post-spermatogonial stages - can also be demonstrated for the induction of dominant cataracts. The dominant cataract mutations recovered can be categorized into 7 phenotypic classes. The only noteworthy difference observed between the radiation- and ENU-induced mutations recovered was that, of the 2 radiation-induced total lens opacities, both were associated with an iris anomaly and microphthalmia whereas the ENU-induced total opacities were not.

  15. Radiation biology of Caenorhabditis elegans. Germ cell response, aging and behavior

    International Nuclear Information System (INIS)

    The study of radiation effect in Caenorhabditis (C.) elegans has been carried out over three decades and now allow for understanding at the molecular, cellular and individual levels. This review describes the current knowledge of the biological effects of ionizing irradiation with a scope of the germ line, aging and behavior. In germ cells, ionizing radiation induces apoptosis, cell cycle arrest and DNA repair. Lots of molecules involved in these responses and functions have been identified in C. elegans, which are highly conserved throughout eukaryotes. Radiosensitivity and the effect of heavy-ion microbeam irradiation on germ cells with relationship between initiation of meiotic recombination and DNA lesions are discussed. In addition to DNA damage, ionizing radiation produces free radicals, and the free radical theory is the most popular aging theory. A first signal transduction pathway of aging has been discovered in C. elegans, and radiation-induced metabolic oxidative stress is recently noted for an inducible factor of hormetic response and genetic instability. The hormetic response in C. elegans exposed to oxidative stress is discussed with genetic pathways of aging. Moreover, C. elegans is well known as a model organism for behavior. The recent work reported the radiation effects via specific neurons on learning behavior, and radiation and hydrogen peroxide affect the locomotory rate similarly. These findings are discussed in relation to the evidence obtained with other organisms. Altogether, C. elegans may be a good 'in vivo' model system in the field of radiation biology. (author)

  16. Effects of ionizing radiation on differentiation of murine bone marrow cells into mast cells

    International Nuclear Information System (INIS)

    Mast cells, immune effector cells produced from bone marrow cells, play a major role in immunoglobulin E–mediated allergic responses. Ionizing radiation affects the functions of mast cells, which are involved in radiation-induced tissue damage. However, whether ionizing radiation affects the differential induction of mast cells is unknown. Here we investigated whether bone marrow cells of X-irradiated mice differentiated into mast cells. To induce mast cells, bone marrow cells from X-irradiated and unirradiated mice were cultured in the presence of cytokines required for mast cell induction. Although irradiation at 0.5 Gy and 2 Gy decreased the number of bone marrow cells 1 day post-irradiation, the cultured bone marrow cells of X-irradiated and unirradiated mice both expressed mast cell–related cell-surface antigens. However, the percentage of mast cells in the irradiated group was lower than in the unirradiated group. Similar decreases in the percentage of mast cells induced in the presence of X-irradiation were observed 10 days post irradiation, although the number of bone marrow cells in irradiated mice had recovered by this time. Analysis of mast cell function showed that degranulation of mast cells after immunoglobulin E–mediated allergen recognition was significantly higher in the X-irradiated group compared with in the unirradiated group. In conclusion, bone marrow cells of X-irradiated mice differentiated into mast cells, but ionizing radiation affected the differentiation efficiency and function of mast cells. (author)

  17. Generation of antigen-specific T cell immunity through T cell receptor gene transfer

    NARCIS (Netherlands)

    Coccoris, Miriam

    2009-01-01

    Cancer cells often escape the attack of immune cells because they originate from self-tissue. Through T cell receptor gene transfer it is possible to equip peripheral T cells with a desired specificity, and this strategy may be useful to generate tumor-specific T cells for the treatment of cancer in

  18. Cone Penetrometer Load Cell Temperature and Radiation Testing Results

    Energy Technology Data Exchange (ETDEWEB)

    Follett, Jordan R.

    2013-08-28

    This report summarizes testing activities performed at the Pacific Northwest National Laboratory to verify the cone penetrometer load cell can withstand the tank conditions present in 241-AN-101 and 241-AN-106. The tests demonstrated the load cell device will operate under the elevated temperature and radiation levels expected to be encountered during tank farm deployment of the device.

  19. Tissue specific heterogeneity in effector immune cell response

    Directory of Open Access Journals (Sweden)

    Saba eTufail

    2013-08-01

    Full Text Available Post pathogen invasion, migration of effector T-cell subsets to specific tissue locations is of prime importance for generation of robust immune response. Effector T cells are imprinted with distinct ‘homing codes’ (adhesion molecules and chemokine receptors during activation which regulate their targeted trafficking to specific tissues. Internal cues in the lymph node microenvironment along with external stimuli from food (vitamin A and sunlight (vitamin D3 prime dendritic cells, imprinting them to play centrestage in the induction of tissue tropism in effector T cells. B cells as well, in a manner similar to effector T cells, exhibit tissue tropic migration. In this review, we have focused on the factors regulating the generation and migration of effector T cells to various tissues alongwith giving an overview of tissue tropism in B cells.

  20. Sensitization of radiation-induced cell death by genistein

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Rim; Kim, In Gyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-03-15

    A number of epidemiological studies as well as biological experiments, showed that genistein, one of the isoflavone, prevents prostate cancer occurrence. In this study, we showed that genistein inhibited the cell proliferation of human promyeoltic leukemia HL-60 cells and induced G2/M phase arrest. In addition, combination of genistein treatment and {gamma}-irradiation displayed synergistic effect in apoptotic cell death of HL-60 cells. This means that the repair of genistein-induced DNA damage was hindered by {gamma}-irradiation and thus cell death was increased. In conclusion, genistein is one of the important chemicals that sensitize radiation-induced cell death.

  1. Mammalian cells exposed to ionizing radiation: structural and biochemical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Sabanero, M.; Flores V, L. L. [Universidad de Guanajuato, Departamento de Biologia, DCNE, Noria Alta s/n, 36250 Guanajuato, Gto. (Mexico); Azorin V, J. C.; Vallejo, M. A.; Cordova F, T.; Sosa A, M. [Universidad de Guanajuato, Departamento de Ingenieria Fisica, DCI, Loma del Bosque 103, Col. Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Castruita D, J. P. [Universidad de Guadalajara, Departamento de Ecologia, CUCBA, Las Agujas, 45100 Zapopan, Jalisco (Mexico); Barbosa S, G., E-mail: myrna.sabanero@gmail.com [Universidad de Guanajuato, Departamento de Ciencias Medicas, DCS, 20 de Enero No. 929, Col. Obregon, 37000 Leon, Guanajuato (Mexico)

    2015-10-15

    Acute or chronic exposure to ionizing radiation is a factor that may be hazardous to health. It has been reported that exposure to low doses of radiation (less than 50 mSv / year) and subsequently exposure to high doses have greater effects in people. However, it is unknown molecular and biochemical level alteration. This study, analyzes the susceptibility of a biological system (HeLa Atcc CCL-2 human cervix cancer cell line) to ionizing radiation (6 and 60 mSv/ 90). Our evaluate multiple variables such as: total protein profile, mitochondrial metabolic activity (XTT assay), cell viability (Trypan blue exclusion assay), cytoskeleton (actin micro filaments), nuclei (D API), genomic DNA. The results indicate, that cells exposed to ionizing radiation structurally show alterations in nuclear phenotype and aneuploidy, further disruption in the tight junctions and consequently on the distribution of actin micro filaments. Similar alterations were observed in cells treated with a genotoxic agent (200μM H{sub 2}O{sub 2}/1 h). In conclusion, this multi-criteria assessment enables precise comparisons of the effects of radiation between any biological systems. However, it is necessary to determine stress markers for integration of the effects of ionizing radiation. (Author)

  2. Consequences of PAI-1 specific deletion in endothelium on radiation-induced intestinal damage

    International Nuclear Information System (INIS)

    Radiation-induced injury to healthy tissues is a real public health problem, since they are one of the most limiting factors that restrict efficiency of radiation therapy. This problematic is also part of the French Cancer Plan 2014-2017, and involves clinical research. Concepts surrounding the development of radiation-induced damage have gradually evolved into a contemporary and integrated view of the pathogenesis, involving all compartments of target tissue. Among them, endothelium seems to be central in the sequence of interrelated events that lead to the development of radiation-induced damage, although there are rare concrete elements that support this concept. By using new transgenic mouse models, this PhD project provides a direct demonstration of an endothelium-dependent continuum in evolution of radiation-induced intestinal damage. Indeed, changes in the endothelial phenotype through targeted deletion of the gene SERPINE1, chosen because of its key role in the development of radiation enteritis, influences various parameters of the development of the disease. Thus, lack of PAI-1 secretion by endothelial cells significantly improves survival of the animals, and limits severity of early and late tissue damage after a localized small bowel irradiation. Furthermore, these mice partially KO for PAI-1 showed a decrease in the number of apoptotic intestinal stem cells in the hours following irradiation, a decrease in the macrophages infiltrate density one week after irradiation, and a change in the polarization of macrophages throughout the pathophysiological process. In an effort to protect healthy tissues from radiation therapy side effects, without hindering the cancer treatment, PAI-1 seems to be an obvious therapeutic target. Conceptually, this work represents the direct demonstration of the link between endothelium phenotype and radiation enteritis pathogenesis. (author)

  3. The regulatory effects of radiation and histone deacetylase inhibitor on liver cancer cell cycle

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sung Ho; Choi, Hyung Seok; Jang, Dong Gun; Lee, Hong Je; Yang, Seoung Oh [Dept. Nuclear Medicine, Dongnam Institute of Radiological and Medicine Sciences Cancer Center, Busan (Korea, Republic of)

    2013-11-15

    Radiation has been an effective tool for treating cancer for a long time. Radiation therapy induces DNA damage within cancer cells and destroys their ability to reproduce. Radiation therapy is often combined with other treatments, like surgery and chemotherapy. Here, we describe the effects of radiation and histone deacetylase inhibitor, Trichostain A, on cell cycle regulation in hepatoma cells. Results demonstrate that the treatment of radiation TSA induces cell cycle arrest, thereby stimulating cell death in hepatoma cells. In addition, since different cells or tissues have different reactivity to radiation and TSA, these results might be an indicator for the combination therapy with radiation and drugs in diverse cancers.

  4. The impact of locally multiply damaged sites (LMDS) induced by ionizing radiation in mammalian cells

    Energy Technology Data Exchange (ETDEWEB)

    Averbeck, D.; Boucher, D. [Institut Curie-Section de Recherche, UMR2027 CNRS, LCR-V28 du CEA, Centre Universitaire, 91405 Orsay Cedex (France)

    2006-07-01

    Monte Carlo calculations have shown that ionising radiations produce a specific type of clustered cell damage called locally multiply damaged sites or LMDS. These lesions consist of closely positioned single-strand breaks, (oxidative) base damage and DNA double-strand breaks (DSB) in between one helical turn of DNA. As specific markers of radiation-induced damage these lesions are likely to condition biological responses and are thus of great interest for radiation protection. Calculations indicate that there should be more LMDS induced by high than by low LET radiation, and they should be absent in un-irradiated cells. Processes like K-shell activation and local Auger electron emission can be expected to add complex DSB or LMDS, producing significant chromosomal damage. In the discussion of the specificity of ionising radiation in comparison to other genotoxic agents, many arguments have been put forward that these lesions should be particularly deleterious for living cells. Complex lesions of that type should represent big obstacles for DNA repair and give rise to high lethality. Moreover, cellular attempts to repair them could accentuate harm, leading to mutations, genetic instability and cancer. In vitro experiments with oligonucleotides containing an artificially introduced set of base damage and SSB in different combinations have shown that depending on the close positioning of the damage on DNA, repair enzymes, and even whole cell extracts, are unable to repair properly and may stimulate mis-repair. Pulsed field gel electrophoresis (PFGE) in conjunction with enzymatic treatments has been used to detect LMDS in mammalian cells after high and low LET radiation. In order to further define the importance of LMDS for radiation induced cellular responses, we studied the induction of LMDS as a function of radiation dose and dose rate in mammalian cells (CHO and MRC5) using {sup 137}Cs gamma-radiation. Using PFGE and specific glycosylases to convert oxidative damage

  5. Strain difference in jejunal crypt cell susceptibility to radiation-induced apoptosis.

    Science.gov (United States)

    Weil, M M; Stephens, L C; Amos, C I; Ruifrok, A C; Mason, K A

    1996-11-01

    Levels of radiation-induced jejunal crypt cell apoptosis were compared in C57BL/6J, C3Hf/Kam and C3H/HeJ mice. Apoptosis levels were consistently lower in the C3H strains than in C57BL/6J. Although other explanations are possible, the strain difference is most likely to have a genetic basis, and in fact a preliminary analysis of the F2 progeny of C3H/HeJ and C57BL/6J mice indicates that more than one gene is involved. Both C3H strains also had lower levels of radiation-induced thymocyte apoptosis than C57BL/6J mice. Jejunal crypt cell apoptosis levels did not co-segregate with thymocyte apoptosis levels in the F2 progeny of C57BL/6J and C3H/HeJ mice. These results imply that the genes responsible for the difference in radiation-induced thymocyte apoptosis levels between these two strains are not the same as those responsible for the strain difference in radiation-induced jejunal crypt cell apoptosis levels. The experiments reported here identify strain-specific differences in levels of radiation-induced crypt cell apoptosis and are a first step towards identifying genetic polymorphisms that influence sensitivity of the small intestine to damage from ionizing radiation.

  6. Freedom of expression: cell-type-specific gene profiling.

    Science.gov (United States)

    Otsuki, Leo; Cheetham, Seth W; Brand, Andrea H

    2014-01-01

    Cell fate and behavior are results of differential gene regulation, making techniques to profile gene expression in specific cell types highly desirable. Many methods now enable investigation at the DNA, RNA and protein level. This review introduces the most recent and popular techniques, and discusses key issues influencing the choice between these such as ease, cost and applicability of information gained. Interdisciplinary collaborations will no doubt contribute further advances, including not just in single cell type but single-cell expression profiling.

  7. Cell Theory, Specificity, and Reproduction, 1837–1870

    OpenAIRE

    Müller-Wille, Staffan

    2010-01-01

    The cell is not only the structural, physiological, and developmental, but also the reproductive unit of life. So far, however, this aspect of the cell has received little attention by historians and philosophers of biology. I will argue that cell theory had far-reaching consequences for how biologists conceptualized the reproductive relationships between germs and adult organisms. Cell theory, as formulated by Theodor Schwann in 1839, implied that this relationship was a specific and lawful ...

  8. New Modeling Approaches to Investigate Cell Signaling in Radiation Response

    Science.gov (United States)

    Plante, Ianik; Cucinotta, Francis A.; Ponomarev, Artem L.

    2011-01-01

    Ionizing radiation damages individual cells and tissues leading to harmful biological effects. Among many radiation-induced lesions, DNA double-strand breaks (DSB) are considered the key precursors of most early and late effects [1] leading to direct mutation or aberrant signal transduction processes. In response to damage, a flow of information is communicated to cells not directly hit by the radiation through signal transduction pathways [2]. Non-targeted effects (NTE), which includes bystander effects and genomic instability in the progeny of irradiated cells and tissues, may be particularly important for space radiation risk assessment [1], because astronauts are exposed to a low fluence of heavy ions and only a small fraction of cells are traversed by an ion. NTE may also have important consequences clinical radiotherapy [3]. In the recent years, new simulation tools and modeling approaches have become available to study the tissue response to radiation. The simulation of signal transduction pathways require many elements such as detailed track structure calculations, a tissue or cell culture model, knowledge of biochemical pathways and Brownian Dynamics (BD) propagators of the signaling molecules in their micro-environment. Recently, the Monte-Carlo simulation code of radiation track structure RITRACKS was used for micro and nano-dosimetry calculations [4]. RITRACKS will be used to calculate the fraction of cells traversed by an ion and delta-rays and the energy deposited in cells in a tissue model. RITRACKS also simulates the formation of chemical species by the radiolysis of water [5], notably the .OH radical. This molecule is implicated in DNA damage and in the activation of the transforming growth factor beta (TGF), a signaling molecule involved in NTE. BD algorithms for a particle near a membrane comprising receptors were also developed and will be used to simulate trajectories of signaling molecules in the micro-environment and characterize autocrine

  9. Entorhinal Cortical Ocean Cells Encode Specific Contexts and Drive Context-Specific Fear Memory.

    Science.gov (United States)

    Kitamura, Takashi; Sun, Chen; Martin, Jared; Kitch, Lacey J; Schnitzer, Mark J; Tonegawa, Susumu

    2015-09-23

    Forming distinct representations and memories of multiple contexts and episodes is thought to be a crucial function of the hippocampal-entorhinal cortical network. The hippocampal dentate gyrus (DG) and CA3 are known to contribute to these functions, but the role of the entorhinal cortex (EC) is poorly understood. Here, we show that Ocean cells, excitatory stellate neurons in the medial EC layer II projecting into DG and CA3, rapidly form a distinct representation of a novel context and drive context-specific activation of downstream CA3 cells as well as context-specific fear memory. In contrast, Island cells, excitatory pyramidal neurons in the medial EC layer II projecting into CA1, are indifferent to context-specific encoding or memory. On the other hand, Ocean cells are dispensable for temporal association learning, for which Island cells are crucial. Together, the two excitatory medial EC layer II inputs to the hippocampus have complementary roles in episodic memory. PMID:26402611

  10. Tumourigenicity and radiation resistance of mesenchymal stem cells

    DEFF Research Database (Denmark)

    D'Andrea, Filippo Peder; Horsman, Michael Robert; Kassem, Moustapha;

    2012-01-01

    Background. Cancer stem cells are believed to be more radiation resistant than differentiated tumour cells of the same origin. It is not known, however, whether normal nontransformed adult stem cells share the same radioresistance as their cancerous counterpart. Material and methods. Nontumourige......Background. Cancer stem cells are believed to be more radiation resistant than differentiated tumour cells of the same origin. It is not known, however, whether normal nontransformed adult stem cells share the same radioresistance as their cancerous counterpart. Material and methods....... Nontumourigenic (TERT4) and tumourigenic (TRET20) cell lines, from an immortalised mesenchymal stem cell line, were grown in culture prior to irradiation and gene expression analysis. Radiation resistance was measured using a clonogenic assay. Differences in gene expression between the two cell lines, both under...... nontreated and irradiated conditions, were assessed with microarrays (Affymetrix Human Exon 1.0 ST array). The cellular functions affected by the altered gene expressions were assessed through gene pathway mapping (Ingenuity Pathway Analysis). Results. Based on the clonogenic assay the nontumourigenic cell...

  11. Radiation Response of Cultured Human Cells Is Unaffected by Johrei

    Directory of Open Access Journals (Sweden)

    Zach Hall

    2007-01-01

    Full Text Available Johrei has been credited with healing thousands from radiation wounds after the Hiroshima and Nagasaki bombs in 1945. This alternative medical therapy is becoming increasingly popular in the United States, as are other Energy Medicine modalities that purport to influence a universal healing energy. Human brain cells were cultured and exposed to increasing doses of ionizing radiation. Experienced Johrei practitioners directed healing intentionality toward the cells for 30 min from a distance of 20 cm and the fate of the cells was observed by computerized time-lapse microscopy. Cell death and cell divisions were tallied every 30 min before, during and after Johrei treatment for a total of 22.5 h. An equal number of control experiments were conducted in which cells were irradiated but did not receive Johrei treatment. Samples were assigned to treatment conditions randomly and data analysis was conducted in a blinded fashion. Radiation exposure decreased the rate of cell division (cell cycle arrest in a dose-dependent manner. Division rates were estimated for each 30 min and averaged over 8 independent experiments (4 control and 4 with Johrei treatment for each of 4 doses of X-rays (0, 2, 4 and 8 Gy. Because few cell deaths were observed, pooled data from the entire observation period were used to estimate death rates. Analysis of variance did not reveal any significant differences on division rate or death rate between treatment groups. Only radiation dose was statistically significant. We found no indication that the radiation response of cultured cells is affected by Johrei treatment.

  12. Radiation response of cultured human cells is unaffected by Johrei.

    Science.gov (United States)

    Hall, Zach; Luu, Tri; Moore, Dan; Yount, Garret

    2007-06-01

    Johrei has been credited with healing thousands from radiation wounds after the Hiroshima and Nagasaki bombs in 1945. This alternative medical therapy is becoming increasingly popular in the United States, as are other Energy Medicine modalities that purport to influence a universal healing energy. Human brain cells were cultured and exposed to increasing doses of ionizing radiation. Experienced Johrei practitioners directed healing intentionality toward the cells for 30 min from a distance of 20 cm and the fate of the cells was observed by computerized time-lapse microscopy. Cell death and cell divisions were tallied every 30 min before, during and after Johrei treatment for a total of 22.5 h. An equal number of control experiments were conducted in which cells were irradiated but did not receive Johrei treatment. Samples were assigned to treatment conditions randomly and data analysis was conducted in a blinded fashion. Radiation exposure decreased the rate of cell division (cell cycle arrest) in a dose-dependent manner. Division rates were estimated for each 30 min and averaged over 8 independent experiments (4 control and 4 with Johrei treatment) for each of 4 doses of X-rays (0, 2, 4 and 8 Gy). Because few cell deaths were observed, pooled data from the entire observation period were used to estimate death rates. Analysis of variance did not reveal any significant differences on division rate or death rate between treatment groups. Only radiation dose was statistically significant. We found no indication that the radiation response of cultured cells is affected by Johrei treatment. PMID:17549235

  13. Specific effect of electromagnetic radiation of SHF on genome and some genetic processes in the norm and in case of radiation injury

    International Nuclear Information System (INIS)

    Modifying effect of electromagnetic radiation of SHF in a wide frequency range on chromosomal aberration yield in various biological objects which is an important test of radiation injury at molecular-cellular level was studied. The presented results testify to the ability of SHF electromagnetic radiation specific effect on the processes of gene expression and to SHD ability to modify radiation injuries at various levels. 13 refs.; 3 figs

  14. Coniferyl Aldehyde Ameliorates Radiation Intestine Injury via Endothelial Cell Survival

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Ye Ji; Jung, Myung Gu; Lee, Yoonjin; Lee, Haejune [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Lee, Yunsil [Ewha Woman' s Univ., Seoul (Korea, Republic of); Ko, Younggyu [Korea Univ., Seoul (Korea, Republic of)

    2014-05-15

    Cancer treatments related gastrointestinal toxicity has also been recognized as a significant economic burden. Especially, extensive apoptosis of microvascular endothelial cell of the lamina propria is the primary lesion initiating intestinal radiation damage after abdominal radiation therapy. Coniferyl aldehyde (CA) is phenolic compounds isolated from cork stoppers, and one of the major pyrolysis products of lignin. Shi H. was support for the empirical use of CA as a medicinal food for cardiovascular diseases. CA has positive effect in broad way but there is no consequence in radiation induced intestine damage. Here, we investigate effect of CA on small intestine after abdominal IR to mice in this study. In this study, CA increased the survival rate in C3H mice against 13.5 Gy abdominal IR. We found CA protects small intestine via preventing endothelial cell apoptosis and enhancing their angiogenic activity. CA also showed protective effect on crypt cell survival. Endothelial cell survival may affect crypt cell protection against IR. From this data, we concluded that CA is effective for protection against abdominal radiation injury. CA could ameliorate side-effect of radiation therapy.

  15. Radiation-induced spindle cell sarcoma: A rare case report

    Directory of Open Access Journals (Sweden)

    Khan Mubeen

    2009-01-01

    Full Text Available Ionizing radiation has been known to induce malignant transformation in human beings. Radiation-induced sarcomas are a late sequel of radiation therapy. Most sarcomas have been reported to occur after exposure to a radiation dose of 55 Gray (Gy and above, with a dose ranging from 16 to 112 Gys. Spindle cell sarcomas, arising after radiotherapy given to treat the carcinoma of head and neck region is a very uncommon sequel. This is a rare case report of spindle cell sarcoma of left maxilla, in a 24-year-old male, occurring as a late complication of radiotherapy with Cobalt-60 given for the treatment of retinoblastoma of the left eye 21 years back.

  16. Examining the specific entropy (density of adiabatic invariants) of the outer electron radiation belt

    Energy Technology Data Exchange (ETDEWEB)

    Borovsky, Joseph E [Los Alamos National Laboratory; Denton, Michael H [LANCASTER UNIV

    2008-01-01

    Using temperature and number-density measurements of the energetic-electron population from multiple spacecraft in geosynchronous orbit, the specific entropy S = T/n{sup 2/3} of the outer electron radiation belt is calculated. Then 955,527 half-hour-long data intervals are statistically analyzed. Local-time and solar-cycle variations in S are examined. The median value of the specific entropy (2.8 x 10{sup 7} eVcm{sup 2}) is much larger than the specific entropy of other particle populations in and around the magnetosphere. The evolution of the specific entropy through high-speed-stream-driven geomagnetic storms and through magnetic-cloud-driven geomagnetic storms is studied using superposed-epoch analysis. For high-speed-stream-driven storms, systematic variations in the entropy associated with electron loss and gain and with radiation-belt heating are observed in the various storm phases. For magnetic-cloud-driven storms, multiple trigger choices for the data superpositions reveal the effects of interplanetary shock arrival, sheath driving, cloud driving, and recovery phase. The specific entropy S = T/n{sup 2/3} is algebraically expressed in terms of the first and second adiabatic invariants of the electrons: this allows a relativistic expression for S in terms of T and n to be derived. For the outer electron radiation belt at geosynchronous orbit, the relativistic corrections to the specific entropy expression are -15%.

  17. Applications of Synchrotron Radiation Micro Beams in Cell Micro Biology and Medicine

    CERN Document Server

    Ide-Ektessabi, Ari

    2007-01-01

    This book demonstrates the applications of synchrotron radiation in certain aspects of cell microbiology, specifically non-destructive elemental analyses, chemical-state analyses and imaging (distribution) of the elements within a cell. The basics for understanding and applications of synchrotron radiation are also described to make the contents easier to be understood for a wide group of researchers in medical and biological sciences who might not be familiar with the physics of synchrotron radiation. The two main techniques that are discussed in this book are the x-ray fluorescence spectroscopy (XRF) and the x-ray fine structure analysis (XAFS). Application of these techniques in investigations of several important scientific fields, such as neurodegeneration and other diseases related to cell malfunctioning, are demonstrated in this book.

  18. Applications of synchrotron radiation. Micro beams in cell micro biology and medicine

    Energy Technology Data Exchange (ETDEWEB)

    Ide-Ektessabi, A. [Kyoto Univ. (Japan). Bio System Electronics

    2007-07-01

    This book demonstrates the applications of synchrotron radiation in certain aspects of cell microbiology, specifically non-destructive elemental analyses, chemical-state analyses and imaging (distribution) of the elements within a cell. The basics for understanding and applications of synchrotron radiation are also described to make the contents easier to be understood for a wide group of researchers in medical and biological sciences who might not be familiar with the physics of synchrotron radiation. The two main techniques that are discussed in this book are the x-ray fluorescence spectroscopy (XRF) and the x-ray fine structure analysis (XAFS). Application of these techniques in investigations of several important scientific fields, such as neurodegeneration and other diseases related to cell malfunctioning, are demonstrated in this book. (orig.)

  19. Functional genomics of UV radiation responses in human cells

    Energy Technology Data Exchange (ETDEWEB)

    Koch-Paiz, Christine A.; Amundson, Sally A.; Bittner, Michael L.; Meltzer, Paul S.; Fornace, Albert J

    2004-05-18

    The gene expression responses of MCF-7, a p53 wild-type (wt) human cell line, were monitored by cDNA microarray hybridization after exposure to different wavelengths of UV irradiation. Equitoxic doses of UVA, UVB, and UVC radiation were used to reduce survival to 37%. The effects of suramin, a signal pathway inhibitor, on the gene expression responses to the three UV wavelengths were also compared in this model system. UVB radiation triggered the broadest gene expression responses, and 172 genes were found to be consistently responsive in at least two-thirds of independent UVB experiments. These UVB radiation-responsive genes encode proteins with diverse cellular roles including cell cycle control, DNA repair, signaling, transcription, protein synthesis, protein degradation, and RNA metabolism. The set of UVB-responsive genes included most of the genes responding to an equitoxic dose of UVC radiation, plus additional genes that were not strongly triggered by UVC radiation. There was also some overlap with genes responding to an equitoxic dose of UVA radiation, although responses to this lower energy UV radiation were overall weaker. Signaling through growth factor receptors and other cytokine receptors was shown to have a major role in mediating UV radiation stress responses, as suramin, which inhibits such receptors, attenuated responses to UV radiation in nearly all the cases. Inhibition by suramin was greater for UVC than for UVB irradiation. This probably reflects the more prominent role in UVB damage response of signaling by reactive oxygen species, which would not be affected by suramin. Our results with suramin demonstrate the power of cDNA microarray hybridization to illuminate the global effects of a pharmacologic inhibitor on cell signaling.

  20. Stimulation of adult oligodendrogenesis by myelin-specific T cells

    DEFF Research Database (Denmark)

    Hvilsted Nielsen, Helle; Toft-Hansen, Henrik; Lambertsen, Kate Lykke;

    2011-01-01

    In multiple sclerosis (MS), myelin-specific T cells are normally associated with destruction of myelin and axonal damage. However, in acute MS plaque, remyelination occurs concurrent with T-cell infiltration, which raises the question of whether T cells might stimulate myelin repair. We investiga...... of calretinergic associational/commissural fibers within the dentate gyrus. These results have implications for the perception of MS pathogenesis because they show that infiltrating myelin-specific T cells can stimulate oligodendrogenesis in the adult central nervous system....

  1. Tumor-specific CD4+ T cells maintain effector and memory tumor-specific CD8+ T cells

    Science.gov (United States)

    Church, Sarah E; Jensen, Shawn M; Antony, Paul A; Restifo, Nicholas P; Fox, Bernard A

    2014-01-01

    Immunotherapies that augment antitumor T cells have had recent success for treating patients with cancer. Here we examined whether tumor-specific CD4+ T cells enhance CD8+ T-cell adoptive immunotherapy in a lymphopenic environment. Our model employed physiological doses of tyrosinase-related protein 1-specific CD4+ transgenic T cells-CD4+ T cells and pmel-CD8+ T cells that when transferred individually were subtherapeutic; however, when transferred together provided significant (p ≤ 0.001) therapeutic efficacy. Therapeutic efficacy correlated with increased numbers of effector and memory CD8+ T cells with tumor-specific cytokine expression. When combined with CD4+ T cells, transfer of total (naïve and effector) or effector CD8+ T cells were highly effective, suggesting CD4+ T cells can help mediate therapeutic effects by maintaining function of activated CD8+ T cells. In addition, CD4+ T cells had a pronounced effect in the early posttransfer period, as their elimination within the first 3 days significantly (p < 0.001) reduced therapeutic efficacy. The CD8+ T cells recovered from mice treated with both CD8+ and CD4+ T cells had decreased expression of PD-1 and PD-1-blockade enhanced the therapeutic efficacy of pmel-CD8 alone, suggesting that CD4+ T cells help reduce CD8+ T-cell exhaustion. These data support combining immunotherapies that elicit both tumor-specific CD4+ and CD8+ T cells for treatment of patients with cancer. PMID:24114780

  2. Radiation-induced motility alterations in medulloblastoma cells

    OpenAIRE

    Rieken, Stefan; Rieber, Juliane; Brons, Stephan; Habermehl, Daniel; Rief, Harald; Orschiedt, Lena; Lindel, Katja; Klaus J. Weber; Debus, Jürgen; Combs, Stephanie E

    2015-01-01

    Photon irradiation has been repeatedly suspected of increasing tumor cell motility and promoting locoregional recurrence of disease. This study was set up to analyse possible mechanisms underlying the potentially radiation-altered motility in medulloblastoma cells. Medulloblastoma cell lines D425 and Med8A were analyzed in migration and adhesion experiments with and without photon and carbon ion irradiation. Expression of integrins was determined by quantitative FACS analysis. Matrix metallop...

  3. Effect of ionizing radiation on human skeletal muscle precursor cells

    OpenAIRE

    Marš, Tomaž; Čemažar, Maja; Jurdana, Mihaela; Pegan, Katarina

    2015-01-01

    Background. Long term effects of different doses of ionizing radiation on human skeletal muscle myoblast proliferation, cytokine signalling and stress response capacity were studied in primary cell cultures.Materials and methods. Human skeletal muscle myoblasts obtained from muscle biopsies were cultured and irradiated with a Darpac 2000 X-ray unit at doses of 4, 6 and 8 Gy. Acute effects of radiation were studied by interleukin - 6 (IL-6) release and stress response detected by the heat shoc...

  4. Proton irradiation of stem cells: Radiation damage and chemical radioprotection

    Science.gov (United States)

    Riley, R. C.; Montour, J. L.; Gurney, C. W.

    1972-01-01

    Effects of high energy protons on erythropoietic stem cells and radioprotection by chemicals were investigated in NASA Space Radiation Effects Laboratory. The effects of a parallel beam of 600 MeV protons. The fluence, when converted to dose, were referenced to the synchrocyclotron beam monitors which were then used to administer radiation exposures. Mice were given graded doses to 300 rads to determine dose-response curve. Other mice received saline, AET, or 5-hydroxytryptamine 10 to 15 minutes before exposure.

  5. RNAi screen reveals host cell kinases specifically involved in Listeria monocytogenes spread from cell to cell.

    Directory of Open Access Journals (Sweden)

    Ryan Chong

    Full Text Available Intracellular bacterial pathogens, such as Listeria monocytogenes and Rickettsia conorii display actin-based motility in the cytosol of infected cells and spread from cell to cell through the formation of membrane protrusions at the cell cortex. Whereas the mechanisms supporting cytosolic actin-based motility are fairly well understood, it is unclear whether specific host factors may be required for supporting the formation and resolution of membrane protrusions. To address this gap in knowledge, we have developed high-throughput fluorescence microscopy and computer-assisted image analysis procedures to quantify pathogen spread in human epithelial cells. We used the approach to screen a siRNA library covering the human kinome and identified 7 candidate kinases whose depletion led to severe spreading defects in cells infected with L. monocytogenes. We conducted systematic validation procedures with redundant silencing reagents and confirmed the involvement of the serine/threonine kinases, CSNK1A1 and CSNK2B. We conducted secondary assays showing that, in contrast with the situation observed in CSNK2B-depleted cells, L. monocytogenes formed wild-type cytosolic tails and displayed wild-type actin-based motility in the cytosol of CSNK1A1-depleted cells. Furthermore, we developed a protrusion formation assay and showed that the spreading defect observed in CSNK1A1-depleted cells correlated with the formation of protrusion that did not resolve into double-membrane vacuoles. Moreover, we developed sending and receiving cell-specific RNAi procedures and showed that CSNK1A was required in the sending cells, but was dispensable in the receiving cells, for protrusion resolution. Finally, we showed that the observed defects were specific to Listeria monocytogenes, as Rickettsia conorii displayed wild-type cell-to-cell spread in CSNK1A1- and CSNK2B-depleted cells. We conclude that, in addition to the specific host factors supporting cytosolic actin

  6. Early specification of dopaminergic phenotype during ES cell differentiation

    Directory of Open Access Journals (Sweden)

    Li Meng

    2007-07-01

    Full Text Available Abstract Background Understanding how lineage choices are made during embryonic stem (ES cell differentiation is critical for harnessing strategies for controlled production of therapeutic somatic cell types for cell transplantation and pharmaceutical drug screens. The in vitro generation of dopaminergic neurons, the type of cells lost in Parkinson's disease patients' brains, requires the inductive molecules sonic hedgehog and FGF8, or an unknown stromal cell derived inducing activity (SDIA. However, the exact identity of the responding cells and the timing of inductive activity that specify a dopaminergic fate in neural stem/progenitors still remain elusive. Results Using ES cells carrying a neuroepithelial cell specific vital reporter (Sox1-GFP and FACS purification of Sox1-GFP neural progenitors, we have investigated the temporal aspect of SDIA mediated dopaminergic neuron specification during ES cell differentiation. Our results establish that SDIA induces a dopaminergic neuron fate in nascent neural stem or progenitor cells at, or prior to, Sox1 expression and does not appear to have further instructive role or neurotrophic activity during late neuronal differentiation of neural precursors. Furthermore, we show that dopaminergic neurons could be produced efficiently in a monolayer differentiation paradigm independent of SDIA activity or exogenous signalling molecules. In this case, the competence for dopaminergic neuron differentiation is also established at the level of Sox1 expression. Conclusion Dopaminergic neurons are specified early during mouse ES cell differentiation. The subtype specification seems to be tightly linked with the acquisition of a pan neuroectoderm fate.

  7. Materials That Enhance Efficiency and Radiation Resistance of Solar Cells

    Science.gov (United States)

    Sun, Xiadong; Wang, Haorong

    2012-01-01

    A thin layer (approximately 10 microns) of a novel "transparent" fluorescent material is applied to existing solar cells or modules to effectively block and convert UV light, or other lower solar response waveband of solar radiation, to visible or IR light that can be more efficiently used by solar cells for additional photocurrent. Meanwhile, the layer of fluorescent coating material remains fully "transparent" to the visible and IR waveband of solar radiation, resulting in a net gain of solar cell efficiency. This innovation alters the effective solar spectral power distribution to which an existing cell gets exposed, and matches the maximum photovoltaic (PV) response of existing cells. By shifting a low PV response waveband (e.g., UV) of solar radiation to a high PV response waveband (e.g. Vis-Near IR) with novel fluorescent materials that are transparent to other solar-cell sensitive wavebands, electrical output from solar cells will be enhanced. This approach enhances the efficiency of solar cells by converting UV and high-energy particles in space that would otherwise be wasted to visible/IR light. This innovation is a generic technique that can be readily implemented to significantly increase efficiencies of both space and terrestrial solar cells, without incurring much cost, thus bringing a broad base of economical, social, and environmental benefits. The key to this approach is that the "fluorescent" material must be very efficient, and cannot block or attenuate the "desirable" and unconverted" waveband of solar radiation (e.g. Vis-NIR) from reaching the cells. Some nano-phosphors and novel organometallic complex materials have been identified that enhance the energy efficiency on some state-of-the-art commercial silicon and thin-film-based solar cells by over 6%.

  8. Seven cases of radiation-induced cutaneous squamous cell carcinoma

    International Nuclear Information System (INIS)

    We report 7 cases of radiation-induced skin cancer. The diagnosis was based on the history of radiotherapy for benign skin diseases (5 cases) and of occupational exposures to medical doctors (2 cases). All cases were squamous cell carcinomas which arose from chronic radiodermatitis. The estimated latent period of these tumors ranged from 6 to 64 years, with an average of 29.9 years. After surgical treatments of the lesions, no local recurrences were observed in all cases. Benign skin diseases had sometimes been treated with low-energy radiation before the 1960s. Considering the estimated latent period, the peak time point of developing risk of radiation-induced skin cancer by such treatment has been already passed, however, the danger of it should not be ignored in future. In association with multiplicity of radiation usage, occupational exposure of radiation may develop the risk of occurrence of skin cancer in future. Therefore, we should recognize that radiation-induced skin cancer is not in the past. In the cases of chronic skin diseases showing warty keratotic growth, erosion and ulcer, we should include chronic radio-dermatitis in the differential diagnosis. It is necessary to recall all patients about the history of radiotherapy or radiation exposure. Rapid histopathological examination is mandatory because of the suspicion of radiation-induced skin cancer. (author)

  9. In vitro cell culture lethal dose submitted to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Carolina S.; Rogero, Sizue O.; Rogero, Jose Roberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: carolina_sm@hotmail.com; Ikeda, Tamiko I.; Cruz, Aurea S. [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil)

    2009-07-01

    The present study was designed to evaluate the in vitro effect of gamma radiation in cell culture of mouse connective tissue exposed to different doses of gamma radiation and under several conditions. The cell viability was analyzed by neutral red uptake methodology. This assay was developed for establish a methodology to be used in the future in the study of resveratrol radioprotection. Resveratrol (3,4',5- trihydroxystilbene), a phenolic phytoalexin that occurs naturally in some spermatophytes, such as grapevines, in response to injury as fungal infections and exposure to ultraviolet light. In the wines this compound is found at high levels and is considered one of the highest antioxidant constituents. The intense antioxidant potential of resveratrol provides many pharmacological activities including cardioprotection, chemoprevention and anti-tumor effects. Our results demonstrated that {sup 60}Co gamma radiation lethal dose (LD50) on NCTC clone 929 cells was about 340Gy. (author)

  10. In vitro cell culture lethal dose submitted to gamma radiation

    International Nuclear Information System (INIS)

    The present study was designed to evaluate the in vitro effect of gamma radiation in cell culture of mouse connective tissue exposed to different doses of gamma radiation and under several conditions. The cell viability was analyzed by neutral red uptake methodology. This assay was developed for establish a methodology to be used in the future in the study of resveratrol radioprotection. Resveratrol (3,4',5- trihydroxystilbene), a phenolic phytoalexin that occurs naturally in some spermatophytes, such as grapevines, in response to injury as fungal infections and exposure to ultraviolet light. In the wines this compound is found at high levels and is considered one of the highest antioxidant constituents. The intense antioxidant potential of resveratrol provides many pharmacological activities including cardioprotection, chemoprevention and anti-tumor effects. Our results demonstrated that 60Co gamma radiation lethal dose (LD50) on NCTC clone 929 cells was about 340Gy. (author)

  11. Effect of Deep Space Radiation on Human Hematopoietic Cells

    Science.gov (United States)

    Kalota, Anna; Bennett, Paula; Swider, Cezary R.; Sutherland, Betsy M.; Gewirtz, Alan M.

    Astronaut flight crews on long-term missions in deep space will be exposed to a unique radiation environment as a result of exposure to galactic cosmic rays (GCR) and solar particle events (SPE). This environment consists predominantly of high energy protons, helium and high charge, high energy (HZE) atomic nuclei from iron predominantly, but all other elements as well. The effect of such particles, alone, or in combination, on human hematopoietic stem and progenitor cells (HSPC) has not been well studied but is clearly of interest since blood forming cells are known to be sensitive to radiation, and irreversible damage to these cells could quickly compromise a mission due to loss of marrow function. To better understand the effects of GCR and SPE on human stem/progenitor cell function, we have exposed partially purified CD34+ normal human marrow cells to protons, radioactive Fe, and Ti, alone, and in combination at varying doses up to 70cGy, and down to 1, 2, and 4 particle hits per nucleus. We then examined the effects of these radiations on HSPC function, as assessed by the ability to form CFU-GEMM, and LTCIC colonies in semi-solid culture medium. At the highest doses (50 and 70cGy), all radiation types tested significantly diminished the ability of CD34+ cells to form such colonies. The number of CFU-GEMM in irradiated samples was 70-90

  12. Distribution of Chromosome Breakpoints in Human Epithelial Cells Exposed to Low- and High-LET Radiations

    Science.gov (United States)

    Hada, Megumi; Cucinotta, Francis; Wu, Honglu

    2009-01-01

    The advantage of the multicolor banding in situ hybridization (mBAND) technique is not only its ability to identify simultaneously both inter- and intrachromosome exchanges, but also the ability to measure the breakpoint location along the length of the chromosome in a precision that is unmatched with other traditional banding techniques. Breakpoints on specific regions of a chromosome have been known to associate with specific cancers. The breakpoint distribution in cells after low- and high-LET radiation exposures will also provide the data for biophysical modeling of the chromatin structure, as well as the data for the modeling the formation of radiation-induced chromosome aberrations. In a series of experiments, we studied low- and high-LET radiation-induced chromosome aberrations using the mBAND technique with chromosome 3 painted in 23 different colored bands. Human epithelial cells (CH1 84B5F5/M10) were exposed in vitro to Cs- 137 rays at both low and high dose rates, secondary neutrons with a broad energy spectrum at a low dose rate and 600 MeV/u Fe ions at a high dose rate. The data of both inter- and intrachromosome aberrations involving the painted chromosome have been reported previously. Here we present data of the location of the chromosome breaks along the length of chromosome 3 in the cells after exposures to each of the four radiation scenarios. In comparison to the expected breakpoint distribution based on the length of the bands, the observed distribution appeared to be non-random for both the low- and high-LET radiations. In particular, hot spots towards both ends of the chromosome were found after low-LET irradiations of either low or high dose rates. For both high-LET radiation types (Fe ions and neutrons), the breakpoint distributions were similar, and were much smoother than that for low-LET radiation. The dependence of the breakpoint distribution on the radiation quality requires further investigations.

  13. Combination Effect of Nimotuzumab with Radiation in Colorectal Cancer Cells

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Hye Kyung; Kim, Mi Sook; Jeong, Jae Hoon [Korea Institute of Radiologicaland Medical Sciences, Seoul (Korea, Republic of)

    2010-11-15

    To investigate the radiosensitizing effect of the selective epidermal growth factor receptor (EGFR) inhibitor nimotuzumab in human colorectal cancer cell lines. Four human colorectal cancer cell lines, HCT-8, LoVo, WiDr, and HCT-116 were treated with nimotuzumab and/or radiation. The effects on cell proliferation, viability, and cell cycle progression were measured by MTT, clonogenic survival assay, flow cytometry, and Western blot. An immunoblot analysis revealed that EGFR phosphorylation was inhibited by nimotuzumab in colorectal cancer cell lines. Under these experimental conditions, pre-treatment with nimotuzumab increased radiosensitivity of colorectal cancer cell lines, except for cell line HCT-116. However, cell proliferation or cell cycle progression was not affected by the addition of nimotuzumab, irrespective of irradiation. Nimotuzumab enhanced the radiosensitivity of colorectal cancer cells in vitro by inhibiting EGFR-mediated cell survival signaling. This study provided a rationale for the clinical application of the selective EGFR inhibitor, nimotuzumab in combination with radiation in colorectal cancer cells.

  14. Removal of radiation damage by subpopulations of plateau-phase Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Specific cellular radiobiology studies are often required to test aspects of the mathematical models developed in the Radiation Dosimetry program. These studies are designed to determine whether specific mathematical expressions, which characterize the expected effect of biochemical mechanisms on observable biological responses, are consistent with the behavior of selected cell lines. Since these tests place stringent requirements on the cellular system, special techniques and culture conditions are required to minimize biological variability. The use of specialized cell populations is providing data on the extent of repair following low doses, and on the changes in the types of damage that can be repaired as the cell progresses toward mitosis. The stationary-phase Chinese hamster ovary (CHO) cells are composed primarily of G(1)-phase cells (83%), with the remainder comprising both G(2) and S phases. Removal of radiation damage by cells was studied in split-dose experiments. To date, we have observed no significant differences in cellular repair rate. This suggests, therefore, that each of the repair processes found in stationary-phase cells is cell-age independent. However, cellular radiation sensitivity does change rapidly and considerably as the cells progress from one phase to the next through the cell cycle. Since the rate of damage removal appears invariant, the change in survival must reflect the efficiency of producing that damage. The experimental data suggest that production of one or another sort of damage probably dominates during specific phases of the cell cycle, while the capacity for removal of all types of damage remains relatively constant

  15. Cell-specific RNA aptamer against human CCR5 specifically targets HIV-1 susceptible cells and inhibits HIV-1 infectivity.

    Science.gov (United States)

    Zhou, Jiehua; Satheesan, Sangeetha; Li, Haitang; Weinberg, Marc S; Morris, Kevin V; Burnett, John C; Rossi, John J

    2015-03-19

    The C-C chemokine receptor type 5 (CCR5) is a receptor expressed by T cells and macrophages that serves as a coreceptor for macrophage-tropic HIV-1. Loss of CCR5 is associated with resistance to HIV-1. Here, we combine the live-cell-based SELEX with high-throughput sequencing technology to generate CCR5 RNA aptamers capable of specifically targeting HIV-1 susceptible cells (as small interfering RNA [siRNA] delivery agent) and inhibiting HIV-1 infectivity (as antiviral agent) via block of the CCR5 required for HIV-1 to enter cells. One of the best candidates, G-3, efficiently bound and was internalized into human CCR5-expressing cells. The G-3 specifically neutralized R5 virus infection in primary peripheral blood mononuclear cells, and in vivo generated human CD4(+) T cells with a nanomolar inhibitory concentration 50%. G-3 was also capable of transferring functional siRNAs to CCR5-expressing cells. Collectively, the cell-specific, internalizing, CCR5-targeted aptamers and aptamer-siRNA conjugates offer promise for overcoming some of the current challenges of drug resistance in HIV-1 by providing cell-type- or tissue-specific delivery of various therapeutic moieties.

  16. Human salivary gland stem cells ameliorate hyposalivation of radiation-damaged rat salivary glands.

    Science.gov (United States)

    Jeong, Jaemin; Baek, Hyunjung; Kim, Yoon-Ju; Choi, Youngwook; Lee, Heekyung; Lee, Eunju; Kim, Eun Sook; Hah, Jeong Hun; Kwon, Tack-Kyun; Choi, Ik Joon; Kwon, Heechung

    2013-11-15

    Salivary function in mammals may be defective for various reasons, such as aging, Sjogren's syndrome or radiation therapy in head and neck cancer patients. Recently, tissue-specific stem cell therapy has attracted public attention as a next-generation therapeutic reagent. In the present study, we isolated tissue-specific stem cells from the human submandibular salivary gland (hSGSCs). To efficiently isolate and amplify hSGSCs in large amounts, we developed a culture system (lasting 4-5 weeks) without any selection. After five passages, we obtained adherent cells that expressed mesenchymal stem cell surface antigen markers, such as CD44, CD49f, CD90 and CD105, but not the hematopoietic stem cell markers, CD34 and CD45, and that were able to undergo adipogenic, osteogenic and chondrogenic differentiation. In addition, hSGSCs were differentiated into amylase-expressing cells by using a two-step differentiation method. Transplantation of hSGSCs to radiation-damaged rat salivary glands rescued hyposalivation and body weight loss, restored acinar and duct cell structure, and decreased the amount of apoptotic cells. These data suggest that the isolated hSGSCs, which may have characteristics of mesenchymal-like stem cells, could be used as a cell therapy agent for the damaged salivary gland.

  17. Factors affecting mutational specificity induced by ionizing radiation and oxidizing radicals

    International Nuclear Information System (INIS)

    We propose to analyze the factors affecting the specificity of mutational change as induced by ionizing radiation and oxidizing radicals. We want to understand not only the rules that affect base substitution, but also the mechanism(s) by which additions and deletions are produced, since detections are a common consequence of radiation. We wish to carry out this analysis in an in vitro mutation system that permits us to analyze the role of base sequence, of polymerase and of mutagenic agent. Our system is designed to screen out most direct breaks as a cause of mutation and should indicate the changes resulting from base damage to the DNA

  18. Surface-modified gold nanorods for specific cell targeting

    Science.gov (United States)

    Wang, Chan-Ung; Arai, Yoshie; Kim, Insun; Jang, Wonhee; Lee, Seonghyun; Hafner, Jason H.; Jeoung, Eunhee; Jung, Deokho; Kwon, Youngeun

    2012-05-01

    Gold nanoparticles (GNPs) have unique properties that make them highly attractive materials for developing functional reagents for various biomedical applications including photothermal therapy, targeted drug delivery, and molecular imaging. For in vivo applications, GNPs need to be prepared with very little or negligible cytotoxicitiy. Most GNPs are, however, prepared using growth-directing surfactants such as cetyl trimethylammonium bromide (CTAB), which are known to have considerable cytotoxicity. In this paper, we describe an approach to remove CTAB to a non-toxic concentration. We optimized the conditions for surface modification with methoxypolyethylene glycol thiol (mPEG), which replaced CTAB and formed a protective layer on the surface of gold nanorods (GNRs). The cytotoxicities of pristine and surface-modified GNRs were measured in primary human umbilical vein endothelial cells and human cell lines derived from hepatic carcinoma cells, embryonic kidney cells, and thyroid papillary carcinoma cells. Cytotoxicity assays revealed that treating cells with GNRs did not significantly affect cell viability except for thyroid papillary carcinoma cells. Thyroid cancer cells were more susceptible to residual CTAB, so CTAB had to be further removed by dialysis in order to use GNRs for thyroid cell targeting. PEGylated GNRs are further modified to present monoclonal antibodies that recognize a specific surface marker, Na-I symporter, for thyroid cells. Antibody-conjugated GNRs specifically targeted human thyroid cells in vitro.

  19. Radiation response of mesenchymal stem cells derived from bone marrow and human pluripotent stem cells

    International Nuclear Information System (INIS)

    Mesenchymal stem cells (MSCs) isolated from human pluripotent stem cells are comparable with bone marrow-derived MSCs in their function and immunophenotype. The purpose of this exploratory study was comparative evaluation of the radiation responses of mesenchymal stem cells derived from bone marrow- (BMMSCs) and from human embryonic stem cells (hESMSCs). BMMSCs and hESMSCs were irradiated at 0 Gy (control) to 16 Gy using a linear accelerator commonly used for cancer treatment. Cells were harvested immediately after irradiation, and at 1 and 5 days after irradiation. Cell cycle analysis, colony forming ability (CFU-F), differentiation ability, and expression of osteogenic-specific runt-related transcription factor 2 (RUNX2), adipogenic peroxisome proliferator-activated receptor gamma (PPARγ), oxidative stress-specific dismutase-1 (SOD1) and Glutathione peroxidase (GPX1) were analyzed. Irradiation arrested cell cycle progression in BMMSCs and hESMSCs. Colony formation ability of irradiated MSCs decreased in a dose-dependent manner. Irradiated hESMSCs showed higher adipogenic differentiation compared with BMMSCs, together with an increase in the adipogenic PPARγ expression. PPARγ expression was upregulated as early as 4 h after irradiation, along with the expression of SOD1. More than 70% downregulation was found in Wnt3A, Wnt4, Wnt7A, Wnt10A and Wnt11 in BMMSCs, but not in hESMSCs. hESMSCs are highly proliferative but radiosensitive compared with BMMSCs. Increased PPARγ expression relative to RUNX2 and downregulation of Wnt ligands in irradiated MSCs suggest Wnt mediated the fate determination of irradiated MSCs. (author)

  20. T-cell regulatory mechanisms in specific immunotherapy

    OpenAIRE

    Jutel, M; Akdis, C. A.

    2008-01-01

    Allergen-specific immunotherapy (SIT) is the only treatment which leads to a lifelong tolerance against previously disease-causing allergens due to restoration of normal immunity against allergens. The description of T-regulatory (Treg) cells being involved in prevention of sensitization to allergens has led to great interest whether they represent a major target for allergen-SIT and whether it would be possible to manipulate Treg cells to increase its efficacy. Activationinduced cell death, ...

  1. Cell-Type Specific Four-Component Hydrogel

    OpenAIRE

    Timo Aberle; Katrin Franke; Elke Rist; Karin Benz; Burkhard Schlosshauer

    2014-01-01

    In the field of regenerative medicine we aim to develop implant matrices for specific tissue needs. By combining two per se, cell-permissive gel systems with enzymatic crosslinkers (gelatin/transglutaminase and fibrinogen/thrombin) to generate a blend (technical term: quattroGel), an unexpected cell-selectivity evolved. QuattroGels were porous and formed cavities in the cell diameter range, possessed gelation kinetics in the minute range, viscoelastic properties and a mechanical strength appr...

  2. Mechanisms of Enhanced Cell Killing at Low Doses: Implications for Radiation Risk

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Peter J. Johnston; Dr. George D. Wilson

    2003-10-15

    We have shown that cell lethality actually measured after exposure to low-doses of low-LET radiation, is markedly enhanced relative to the cell lethality previously expected by extrapolation of the high-dose cell-killing response. Net cancer risk is a balance between cell transformation and cell kill and such enhanced lethality may more than compensate for transformation at low radiation doses over a least the first 10 cGy of low-LET exposure. This would lead to a non-linear, threshold, dose-risk relationship. Therefore our data imply the possibility that the adverse effects of small radiation doses (<10 cGy) could be overestimated in specific cases. It is now important to research the mechanisms underlying the phenomenon of low-dose hypersensitivity to cell killing, in order to determine whether this can be generalized to safely allow an increase in radiation exposure limits. This would have major cost-reduction implications for the whole EM program.

  3. Treatment of radiation syndrome with emphasis on stem cell implantation

    International Nuclear Information System (INIS)

    Within few years, the possibility that the human body contains cells that can repair and regenerate damaged and diseased tissue has gone from an unlikely proposition to a virtual certainty. Patients who have received doses of radiation in the potentially low to mid-lethal range (2-6 Gy) will have depression in bone-marrow function with cessation of blood-cell production leading to pancytopenia. Selection of cases for stem cell transplantation is based upon clinical signs and symptoms. Hematopoietic stem cell which produces blood cell progeny provides support for hematopoietic and other cells within the marrow, and has also been a focus for possible tissue repair. Another cell type termed mesenchymal or stromal also exists in the marrow. This cell provides support for hematopoietic and other cells within the marrow, and has also been a focus for possible tissue repair. Stem cells are obtained from bone marrow, peripheral blood, placental and umbilical cord blood, embryonic stem cells and embryonic germ cells. These cells have great potential for clinical research due to their potential to regenerate tissue. As well known, the cryo preservation process can store any cell type, particularly blood cells, for an indeterminate time. (author)

  4. Human Y-79 retinoblastoma cells exhibit specific insulin receptors

    Energy Technology Data Exchange (ETDEWEB)

    Saviolakis, G.A.; Kyritsis, A.P.; Chader, G.J.

    1986-07-01

    The presence of insulin receptors was investigated in human Y-79 retinoblastoma cells grown in suspension culture. The binding of (/sup 125/I) insulin to these cells was time, temperature, and pH dependent, was competed for by insulin and proinsulin but not other peptides, and was inhibited by antibodies against the insulin receptor. The Scatchard plot of insulin competition data was curvilinear and was resolved into a high-affinity (KD approximately 0.5 X 10(-9) M)/low-capacity (approximately 3000 sites/cell) and a low-affinity (KD approximately 1 X 10(-7) M)/high-capacity (approximately 155,000 sites/cell) component. Negative cooperativity was not found, in agreement with other studies in rodent neural cells. However, in contrast to studies with rodent cells, insulin specifically down-regulated its receptor on human Y-79 cells after prolonged exposure. In conclusion, these data show for the first time the presence of specific insulin receptors in human Y-79 retinoblastoma cells. Because these cells were previously shown to have several characteristics typical of neural cells, we propose their use as a model to study the effects of insulin on neural and retinal tissues of human origin.

  5. Radiative efficiency of lead iodide based perovskite solar cells

    OpenAIRE

    Kristofer Tvingstedt; Olga Malinkiewicz; Andreas Baumann; Carsten Deibel; Snaith, Henry J.; Vladimir Dyakonov; Bolink, Henk J.

    2015-01-01

    The maximum efficiency of any solar cell can be evaluated in terms of its corresponding ability to emit light. We herein determine the important figure of merit of radiative efficiency for Methylammonium Lead Iodide perovskite solar cells and, to put in context, relate it to an organic photovoltaic (OPV) model device. We evaluate the reciprocity relation between electroluminescence and photovoltaic quantum efficiency and conclude that the emission from the perovskite devices is dominated by a...

  6. Technical specifications manual for the MARK-1 pulsed ionizing radiation detection system

    International Nuclear Information System (INIS)

    The MARK-1 detection system was developed by the Idaho National Engineering Laboratory for the US Department of Energy Office of Arms Control and Nonproliferation. The completely portable system was designed for the detection and analysis of intense photon emissions from pulsed ionizing radiation sources. This manual presents the technical design specifications for the MARK-1 detection system and was written primarily to assist the support or service technician in the service, calibration, and repair of the system. The manual presents the general detection system theory, the MARK-1 component design specifications, the acquisition and control software, the data processing sequence, and the system calibration procedure. A second manual entitled: Volume 2: Operations Manual for the MARK-1 Pulsed Ionizing Radiation Detection System (USDOE Report WINCO-1108, September 1992) provides a general operational description of the MARK-1 detection system. The Operations Manual was written primarily to assist the field operator in system operations and analysis of the data

  7. Technical specifications manual for the MARK-1 pulsed ionizing radiation detection system. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, R.S.; Harker, Y.D.; Jones, J.L.; Hoggan, J.M.

    1993-03-01

    The MARK-1 detection system was developed by the Idaho National Engineering Laboratory for the US Department of Energy Office of Arms Control and Nonproliferation. The completely portable system was designed for the detection and analysis of intense photon emissions from pulsed ionizing radiation sources. This manual presents the technical design specifications for the MARK-1 detection system and was written primarily to assist the support or service technician in the service, calibration, and repair of the system. The manual presents the general detection system theory, the MARK-1 component design specifications, the acquisition and control software, the data processing sequence, and the system calibration procedure. A second manual entitled: Volume 2: Operations Manual for the MARK-1 Pulsed Ionizing Radiation Detection System (USDOE Report WINCO-1108, September 1992) provides a general operational description of the MARK-1 detection system. The Operations Manual was written primarily to assist the field operator in system operations and analysis of the data.

  8. Cell-specific DNA methylation patterns of retina-specific genes.

    Directory of Open Access Journals (Sweden)

    Shannath L Merbs

    Full Text Available Many studies have demonstrated that epigenetic mechanisms are important in the regulation of gene expression during embryogenesis, gametogenesis, and other forms of tissue-specific gene regulation. We sought to explore the possible role of epigenetics, specifically DNA methylation, in the establishment and maintenance of cell type-restricted gene expression in the retina. To assess the relationship between DNA methylation status and expression level of retinal genes, bisulfite sequence analysis of the 1000 bp region around the transcription start sites (TSS of representative rod and cone photoreceptor-specific genes and gene expression analysis were performed in the WERI and Y79 human retinoblastoma cell lines. Next, the homologous genes in mouse were bisulfite sequenced in the retina and in non-expressing tissues. Finally, bisulfite sequencing was performed on isolated photoreceptor and non-photoreceptor retinal cells isolated by laser capture microdissection. Differential methylation of rhodopsin (RHO, retinal binding protein 3 (RBP3, IRBP cone opsin, short-wave-sensitive (OPN1SW, cone opsin, middle-wave-sensitive (OPN1MW, and cone opsin, long-wave-sensitive (OPN1LW was found in the retinoblastoma cell lines that inversely correlated with gene expression levels. Similarly, we found tissue-specific hypomethylation of the promoter region of Rho and Rbp3 in mouse retina as compared to non-expressing tissues, and also observed hypomethylation of retinal-expressed microRNAs. The Rho and Rbp3 promoter regions were unmethylated in expressing photoreceptor cells and methylated in non-expressing, non-photoreceptor cells from the inner nuclear layer. A third regional hypomethylation pattern of photoreceptor-specific genes was seen in a subpopulation of non-expressing photoreceptors (Rho in cones from the Nrl -/- mouse and Opn1sw in rods. These results demonstrate that a number of photoreceptor-specific genes have cell-specific differential DNA

  9. Effect of ionizing radiation on nitric oxide production in mouse mammary epithelial cells

    International Nuclear Information System (INIS)

    Full text: Nitric oxide (NO) is an important biological molecule with a wide variety of functions in physiological and pathophysiological events. We reported previously the presence of nitric oxide synthase (NOS) isoforms such as inducible, endothelial and neuronal types in the rat mammary glands. In addition, we demonstrated that a selective inhibitor of inducible NOS and NO-specific scavenger prevent radiation-induced rat mammary tumors, and that radiation-induced NO might contribute to tumor initiation of mammary glands in rat. However, the production and action of NO in the epithelium of mammary glands after the exposure of radiation are still unclear. In this current study we, therefore, examined the effects of ionizing radiation on a mouse mammary epithelial cell line (HC11) to provide a concrete evidence regarding the production of NO in the mammary epithelial cells after irradiation. The HC11 cells, established from COMMA-1D mouse mammary epithelial cell line, were cultured in RPMI-1640 growth medium containing 10% FCS, EGF and insulin until become confluence, then irradiated by X-ray with a dose at 10 or 30 Gy (1 Gy/min). After the irradiation, NO produced and secreted by HC11 cells into culture medium was estimated by the measurement of nitrite concentration in the culture medium with a Griess assay. HC11 cells produced NO spontaneously, and NO concentration was gradually increased during the experimented period. On the other hand, NO production was transiently enhanced immediately after irradiation of the cells in a dose-dependent manner. It, then, descended in an hour after irradiation, and returned to a basal level in 24 hours. These indicate that NO production was undoubtedly increased by irradiation in mammary epithelial cells, and support our previous propose that radiation-induced NO might contribute to initiation of tumorigenesis of mammary glands

  10. Radiation-induced motility alterations in medulloblastoma cells.

    Science.gov (United States)

    Rieken, Stefan; Rieber, Juliane; Brons, Stephan; Habermehl, Daniel; Rief, Harald; Orschiedt, Lena; Lindel, Katja; Weber, Klaus J; Debus, Jürgen; Combs, Stephanie E

    2015-05-01

    Photon irradiation has been repeatedly suspected of increasing tumor cell motility and promoting locoregional recurrence of disease. This study was set up to analyse possible mechanisms underlying the potentially radiation-altered motility in medulloblastoma cells. Medulloblastoma cell lines D425 and Med8A were analyzed in migration and adhesion experiments with and without photon and carbon ion irradiation. Expression of integrins was determined by quantitative FACS analysis. Matrix metalloproteinase concentrations within cell culture supernatants were investigated by enzyme-linked immunosorbent assay (ELISA). Statistical analysis was performed using Student's t-test. Both photon and carbon ion irradiation significantly reduced chemotactic medulloblastoma cell transmigration through 8-μm pore size membranes, while simultaneously increasing adherence to fibronectin- and collagen I- and IV-coated surfaces. Correspondingly, both photon and carbon ion irradiation downregulate soluble MMP9 concentrations, while upregulating cell surface expression of proadhesive extracellular matrix protein-binding integrin α5. The observed phenotype of radiation-altered motility is more pronounced following carbon ion than photon irradiation. Both photon and (even more so) carbon ion irradiation are effective in inhibiting medulloblastoma cell migration through downregulation of matrix metalloproteinase 9 and upregulation of proadhesive cell surface integrin α5, which lead to increased cell adherence to extracellular matrix proteins. PMID:25736470

  11. beta1-integrin-mediated signaling essentially contributes to cell survival after radiation-induced genotoxic injury

    DEFF Research Database (Denmark)

    Cordes, N; Seidler, J; Durzok, R;

    2006-01-01

    Integrin-mediated adhesion to extracellular matrix proteins confers resistance to radiation- or drug-induced genotoxic injury. To analyse the underlying mechanisms specific for beta1-integrins, wild-type beta1A-integrin-expressing GD25beta1A cells were compared to GD25beta1B cells, which express...

  12. Cell-specific monitoring of protein synthesis in vivo.

    Directory of Open Access Journals (Sweden)

    Nikos Kourtis

    Full Text Available Analysis of general and specific protein synthesis provides important information, relevant to cellular physiology and function. However, existing methodologies, involving metabolic labelling by incorporation of radioactive amino acids into nascent polypeptides, cannot be applied to monitor protein synthesis in specific cells or tissues, in live specimens. We have developed a novel approach for monitoring protein synthesis in specific cells or tissues, in vivo. Fluorescent reporter proteins such as GFP are expressed in specific cells and tissues of interest or throughout animals using appropriate promoters. Protein synthesis rates are assessed by following fluorescence recovery after partial photobleaching of the fluorophore at targeted sites. We evaluate the method by examining protein synthesis rates in diverse cell types of live, wild type or mRNA translation-defective Caenorhabditis elegans animals. Because it is non-invasive, our approach allows monitoring of protein synthesis in single cells or tissues with intrinsically different protein synthesis rates. Furthermore, it can be readily implemented in other organisms or cell culture systems.

  13. Suppressor cells in transplantation tolerance: the mechanisms of tolerance in radiation chimeras

    International Nuclear Information System (INIS)

    Histoincompatible-complete radiation chimeras, after resolving acute graft-vs-host (GVHD), establish specific tolerance to host and donor alloantigens. This tolerance can be perturbed with immunosuppressive agents and infusions of small numbers of donor-type cells with infusions of massive numbers of donor-type cells, or with infusions of a small number of donor-type cells, that were sensitized against host antigens prior to transfer. These chimeras possess T lymphocytes in the spleen that specifically suppress donor to host mixed lymphocyte reactions and adoptively transfer suppression of GVHD to secondary hosts. Nylon-wool fractionation of chimeric spleen cells restores the response of chimeric lymphocytes to host alloantigens, suggesting that transplantation tolerance is not attributable to clonal deletion but the activity of nylon-wool-adherent T suppressor spleen cells

  14. Gene expression profile of Jurkat cells exposed to high power terahertz radiation

    Science.gov (United States)

    Grundt, Jessica E.; Roth, Caleb C.; Rivest, Benjamin D.; Doroski, Michael L.; Payne, Jason; Ibey, Bennett L.; Wilmink, Gerald J.

    2011-03-01

    Terahertz (THz) radiation sources are now being used in a host of military, defense, and medical applications. Widespread employment of these applications has prompted concerns regarding the health effects associated with THz radiation. In this study, we examined the gene expression profile of mammalian cells exposed to THz radiation. We hypothesized that if THz radiation couples directly to cellular constituents, then exposed cells may express a specific gene expression profile indicative of ensuing damage. To test this hypothesis, Jurkat cells were irradiated with a molecular gas THz laser (2.52 THz, 636 mWcm-2, durations: 5, 10, 20, 30, 40, or 50 minutes). Viability was assessed 24 h post-exposure using MTT assays, and gene expression profiles were evaluated 4 h post-exposure using mRNA microarrays. Comparable analyses were also performed for hyperthermic positive controls (44°C for 40 minutes). We found that cellular temperatures increased by ~6 °C during THz exposures. We also found that cell death increased with exposure duration, and the median lethal dose (LD50) was calculated to be ~44 minutes. The microarray data showed that THz radiation induced the transcriptional activation of genes associated with cellular proliferation, differentiation, transcriptional activation, chaperone protein stabilization, and apoptosis. For most genes, we found that the magnitude of differential expression was comparable for both the THz and thermal exposure groups; however, several genes were specifically activated by the THz exposure. These results suggest that THz radiation may elicit effects that are not exclusively due to the temperature rise created during THz exposures (i.e. thermal effects). In future work, we plan to verify the results of our microarray experiments using qPCR techniques.

  15. Cancer Stem Cells, Cancer Cell Plasticity and Radiation Therapy

    OpenAIRE

    Vlashi, Erina; Pajonk, Frank

    2014-01-01

    Since the first prospective identification of cancer stem cells in solid cancers the cancer stem cell hypothesis has reemerged as a research topic of increasing interest. It postulates that solid cancers are organized hierarchically with a small number of cancer stem cells driving tumor growth, repopulation after injury and metastasis. They give rise to differentiated progeny, which lack these features. The model predicts that for any therapy to provide cure, all cancer stem cells have to be ...

  16. uPAR and cathepsin B inhibition enhanced radiation-induced apoptosis in gliomainitiating cells

    OpenAIRE

    MALLA, RAMA RAO; Gopinath, Sreelatha; Alapati, Kiranmai; Gorantla, Bharathi; Christopher S Gondi; Rao, Jasti S.

    2012-01-01

    Glioblastomas present as diffuse tumors with invasion into normal brain tissue and frequently recur or progress after radiation as focal masses because of glioma-initiating cells. The role of the urokinase-type plasminogen activator receptor (uPAR) and cathepsin B in stem-like phenotype has been extensively studied in several solid tumors. In the present study, we demonstrated that selection of glioma-initiating cells using CD133 expression leads to a specific enrichment of CD133+ cells in bo...

  17. Secondary specific immune response in vitro to MSV tumor cells.

    Science.gov (United States)

    Senik, A; Hebrero, F P; Levy, J P

    1975-12-15

    The interactions which occur between antigenic tumor cells and normal or immune lymphoid cells in a 3-day in vitro culture, have been studied with a murine sarcoma virus (MSV)-induced tumor. The 3H-thymidine incorporation of lymphoma cells growing in suspension, and the radioactive-chromium release of freshly sampled lymphoma cells regularly added to the culture, have been compared to determine the part played by immune lymphoid cells in cytolysis and cytostasis of the tumor-cell population. The cytolytic activity increases in the culture from day 0 to day 3. It is due, predominantly, to T-cells, and remains specific to antigens shared by MSV tumors and related lymphomas. This activity would be difficult to detect unless freshly sampled ascitic cells were used as targets, since the lymphoma cells spontaneously lose a part of their sensitivity to immune cytolysis during in vitro culture. The method used in the present experiments is a secondary chromium release test (SCRT), which measures the invitro secondary stimulation of cytotoxic T-lymphocytes (CTL) by tumor cells. In the absence of stimulatory cells, the CTL activity would have rapidly fallen in vitro. The cytostatic activity also increases during the 3 days in vitro, in parallel to the cytolytic activity: it is due to non-T-cells and remains mainly non-specific. The significance of these data for the interpretation of invitro demonstrated cell-mediated anti-tumor immune reactions is briefly discussed, as well as their relevance in the in vivo role of immune CTL. PMID:53210

  18. Coniferyl aldehyde attenuates radiation enteropathy by inhibiting cell death and promoting endothelial cell function.

    Directory of Open Access Journals (Sweden)

    Ye-Ji Jeong

    Full Text Available Radiation enteropathy is a common complication in cancer patients. The aim of this study was to investigate whether radiation-induced intestinal injury could be alleviated by coniferyl aldehyde (CA, an HSF1-inducing agent that increases cellular HSP70 expression. We systemically administered CA to mice with radiation enteropathy following abdominal irradiation (IR to demonstrate the protective effects of CA against radiation-induced gastrointestinal injury. CA clearly alleviated acute radiation-induced intestinal damage, as reflected by the histopathological data and it also attenuated sub-acute enteritis. CA prevented intestinal crypt cell death and protected the microvasculature in the lamina propria during the acute and sub-acute phases of damage. CA induced HSF1 and HSP70 expression in both intestinal epithelial cells and endothelial cells in vitro. Additionally, CA protected against not only the apoptotic cell death of both endothelial and epithelial cells but also the loss of endothelial cell function following IR, indicating that CA has beneficial effects on the intestine. Our results provide novel insight into the effects of CA and suggest its role as a therapeutic candidate for radiation-induced enteropathy due to its ability to promote rapid re-proliferation of the intestinal epithelium by the synergic effects of the inhibition of cell death and the promotion of endothelial cell function.

  19. Radiation rescue: mesenchymal stromal cells protect from lethal irradiation.

    Directory of Open Access Journals (Sweden)

    Claudia Lange

    Full Text Available BACKGROUND: Successful treatment of acute radiation syndromes relies on immediate supportive care. In patients with limited hematopoietic recovery potential, hematopoietic stem cell (HSC transplantation is the only curative treatment option. Because of time consuming donor search and uncertain outcome we propose MSC treatment as an alternative treatment for severely radiation-affected individuals. METHODS AND FINDINGS: Mouse mesenchymal stromal cells (mMSCs were expanded from bone marrow, retrovirally labeled with eGFP (bulk cultures and cloned. Bulk and five selected clonal mMSCs populations were characterized in vitro for their multilineage differentiation potential and phenotype showing no contamination with hematopoietic cells. Lethally irradiated recipients were i.v. transplanted with bulk or clonal mMSCs. We found a long-term survival of recipients with fast hematopoietic recovery after the transplantation of MSCs exclusively without support by HSCs. Quantitative PCR based chimerism analysis detected eGFP-positive donor cells in peripheral blood immediately after injection and in lungs within 24 hours. However, no donor cells in any investigated tissue remained long-term. Despite the rapidly disappearing donor cells, microarray and quantitative RT-PCR gene expression analysis in the bone marrow of MSC-transplanted animals displayed enhanced regenerative features characterized by (i decreased proinflammatory, ECM formation and adhesion properties and (ii boosted anti-inflammation, detoxification, cell cycle and anti-oxidative stress control as compared to HSC-transplanted animals. CONCLUSIONS: Our data revealed that systemically administered MSCs provoke a protective mechanism counteracting the inflammatory events and also supporting detoxification and stress management after radiation exposure. Further our results suggest that MSCs, their release of trophic factors and their HSC-niche modulating activity rescue endogenous hematopoiesis

  20. Type-specific cell line models for type-specific ovarian cancer research.

    Directory of Open Access Journals (Sweden)

    Michael S Anglesio

    Full Text Available BACKGROUND: OVARIAN CARCINOMAS CONSIST OF AT LEAST FIVE DISTINCT DISEASES: high-grade serous, low-grade serous, clear cell, endometrioid, and mucinous. Biomarker and molecular characterization may represent a more biologically relevant basis for grouping and treating this family of tumors, rather than site of origin. Molecular characteristics have become the new standard for clinical pathology, however development of tailored type-specific therapies is hampered by a failure of basic research to recognize that model systems used to study these diseases must also be stratified. Unrelated model systems do offer value for study of biochemical processes but specific cellular context needs to be applied to assess relevant therapeutic strategies. METHODS: We have focused on the identification of clear cell carcinoma cell line models. A panel of 32 "ovarian cancer" cell lines has been classified into histotypes using a combination of mutation profiles, IHC mutation-surrogates, and a validated immunohistochemical model. All cell lines were identity verified using STR analysis. RESULTS: Many described ovarian clear cell lines have characteristic mutations (including ARID1A and PIK3CA and an overall molecular/immuno-profile typical of primary tumors. Mutations in TP53 were present in the majority of high-grade serous cell lines. Advanced genomic analysis of bona-fide clear cell carcinoma cell lines also support copy number changes in typical biomarkers such at MET and HNF1B and a lack of any recurrent expressed re-arrangements. CONCLUSIONS: As with primary ovarian tumors, mutation status of cancer genes like ARID1A and TP53 and a general immuno-profile serve well for establishing histotype of ovarian cancer cell We describe specific biomarkers and molecular features to re-classify generic "ovarian carcinoma" cell lines into type specific categories. Our data supports the use of prototype clear cell lines, such as TOV21G and JHOC-5, and questions the use of

  1. Cell-specific information processing in segregating populations of Eph receptor ephrin-expressing cells

    DEFF Research Database (Denmark)

    Jørgensen, Claus; Sherman, Andrew; Chen, Ginny I;

    2009-01-01

    information is processed in two interacting cell types remains a challenge. We implemented a proteomic strategy to systematically determine cell-specific signaling networks underlying EphB2- and ephrin-B1-controlled cell sorting. Quantitative mass spectrometric analysis of mixed populations of EphB2...... revealed that signaling between mixed EphB2- and ephrin-B1-expressing cells is asymmetric and that the distinct cell types use different tyrosine kinases and targets to process signals induced by cell-cell contact. We provide systems- and cell-specific network models of contact-initiated signaling between......- and ephrin-B1-expressing cells that were labeled with different isotopes revealed cell-specific tyrosine phosphorylation events. Functional associations between these phosphotyrosine signaling networks and cell sorting were established with small interfering RNA screening. Data-driven network modeling...

  2. Cell-type specific four-component hydrogel.

    Science.gov (United States)

    Aberle, Timo; Franke, Katrin; Rist, Elke; Benz, Karin; Schlosshauer, Burkhard

    2014-01-01

    In the field of regenerative medicine we aim to develop implant matrices for specific tissue needs. By combining two per se, cell-permissive gel systems with enzymatic crosslinkers (gelatin/transglutaminase and fibrinogen/thrombin) to generate a blend (technical term: quattroGel), an unexpected cell-selectivity evolved. QuattroGels were porous and formed cavities in the cell diameter range, possessed gelation kinetics in the minute range, viscoelastic properties and a mechanical strength appropriate for general cell adhesion, and restricted diffusion. Cell proliferation of endothelial cells, chondrocytes and fibroblasts was essentially unaffected. In contrast, on quattroGels neither endothelial cells formed vascular tubes nor did primary neurons extend neurites in significant amounts. Only chondrocytes differentiated properly as judged by collagen isoform expression. The biophysical quattroGel characteristics appeared to leave distinct cell processes such as mitosis unaffected and favored differentiation of sessile cells, but hampered differentiation of migratory cells. This cell-type selectivity is of interest e.g. during articular cartilage or invertebral disc repair, where pathological innervation and angiogenesis represent adverse events in tissue engineering. PMID:24475174

  3. Cell-type specific four-component hydrogel.

    Directory of Open Access Journals (Sweden)

    Timo Aberle

    Full Text Available In the field of regenerative medicine we aim to develop implant matrices for specific tissue needs. By combining two per se, cell-permissive gel systems with enzymatic crosslinkers (gelatin/transglutaminase and fibrinogen/thrombin to generate a blend (technical term: quattroGel, an unexpected cell-selectivity evolved. QuattroGels were porous and formed cavities in the cell diameter range, possessed gelation kinetics in the minute range, viscoelastic properties and a mechanical strength appropriate for general cell adhesion, and restricted diffusion. Cell proliferation of endothelial cells, chondrocytes and fibroblasts was essentially unaffected. In contrast, on quattroGels neither endothelial cells formed vascular tubes nor did primary neurons extend neurites in significant amounts. Only chondrocytes differentiated properly as judged by collagen isoform expression. The biophysical quattroGel characteristics appeared to leave distinct cell processes such as mitosis unaffected and favored differentiation of sessile cells, but hampered differentiation of migratory cells. This cell-type selectivity is of interest e.g. during articular cartilage or invertebral disc repair, where pathological innervation and angiogenesis represent adverse events in tissue engineering.

  4. Pharmacological inhibition of radiation induced in vitro tumor cell/endothelium cell interactions and in vivo metastasis processes

    International Nuclear Information System (INIS)

    Exposure of endothelial cells with ionizing radiation (IR) or treatment with inflammatory cytokines (e. g. TNFα) induces a Rho-GTPase and NF-κB dependent activation of the expression of various cell adhesion molecules, including E-selectin. E-selectin mediates the adhesion of tumor cells (TC) to endothelial cells and is probably involved in the extravasation step of circulating tumor cells. HMG-CoA reductase inhibitors (e. g. lovastatin) inhibit the function of Rho-GTPases and thus are anticipated to attenuate Rho-regulated cell-cell-adhesion as well. This study focuses on the influence of IR and TNFα on the expression of endothelial- and/or tumor cell-specific pro-adhesive factors and whether these effects are influenced by lovastatin. To this end, the effect of IR and TNFα on cell-cell-interactions between human colon carcinoma cells (HT29) and human umbilical vein endothelial cells (HUVEC) was investigated using an ELISA-based cell adhesion-assay. Moreover, the influence of pre-treatment with lovastatin and other types of inhibitors on HUVEC-HT29 adhesion was monitored. Additionally, we investigated the effect of lovastatin on mRNA expression level of different cell adhesion molecules, metastatic factors and DNA-repair genes upon radiation exposure by qRT-PCR. To scrutinize the in vivo relevance of the data obtained, we investigated the effect of total body irradiation (TBI) on the mRNA expression of pro-adhesive factors in BALB/c mice. To analyze tumor cell extravasation, tumor cells were injected into the lateral tail vein of immundeficient mice, followed by total body irradiation (TBI, 4 Gy). After four weeks a large increase of lung metastases was monitored, which could be blocked by preatreatment of the mice with lovastatin, the Rac1-specific small-molecule inhibitor NSC23766 as well as the sLex-mimetic glycyrrhizin. Summarizing, we provide evidence, that irradiation promotes upregulation of different cell adhesion molecules in vitro and stimulates

  5. Thalidomide effect in endothelial cell of acute radiation proctitis

    Institute of Scientific and Technical Information of China (English)

    Ki-Tae Kim; Hiun-Suk Chae; Jin-Soo Kim; Hyung-Keun Kim; Young-Seok Cho; Whang Choi; Kyu-Yong Choi; Sang-Young Rho; Suk-Jin Kang

    2008-01-01

    AIM: To determine whether thalidomide prevents microvascular injury in acute radiation proctitis in white rats. METHODS: Fourteen female Wistar rats were used:six in the radiation group,six in the thalidomide group,and two in normal controls.The radiation and thalidomide groups were irradiated at the pelvic area using a single 30 Gy exposure.The thalidomide (150 mg/kg) was injected into the peritoneum for 7 d from the day of irradiation.All animals were sacrificed and the rectums were removed on day 8 after irradiation.The microvessels of resected specimens were immunohistochemically stained with thrombomodulin (TM),yon Willebrand Factor (vWF),and vascular endothelial growth factor (VEGF).RESULTS: The microscopic scores did not differ significantly between the radiation and thalidomide groups,but both were higher than in the control group.Expression of TM was significantly lower in the endothelial cells (EC) of the radiation group than in the control and thalidomide groups (P < 0.001).The number of capillaries expressing vWF in the EC was higher in the radiation group (15.3 ± 6.8) than in the control group (3.7 ± 1.7),and the number of capillaries expressing vWF was attenuated by thalidomide (10.8 ± 3.5,P < 0.001).The intensity of VEGF expression in capillaries was greater in the radiation group than in the control group and was also attenuated by thalidomide (P = 0.003).CONCLUSION: The mechanisms of acute radiationinduced proctitis in the rats are related to endothelial cell injury of microvessel,which may be attenuated with thalidomide.

  6. Classical radiation reaction in particle-in-cell simulations

    Science.gov (United States)

    Vranic, M.; Martins, J. L.; Fonseca, R. A.; Silva, L. O.

    2016-07-01

    Under the presence of ultra high intensity lasers or other intense electromagnetic fields the motion of particles in the ultrarelativistic regime can be severely affected by radiation reaction. The standard particle-in-cell (PIC) algorithms do not include radiation reaction effects. Even though this is a well known mechanism, there is not yet a definite algorithm nor a standard technique to include radiation reaction in PIC codes. We have compared several models for the calculation of the radiation reaction force, with the goal of implementing an algorithm for classical radiation reaction in the Osiris framework, a state-of-the-art PIC code. The results of the different models are compared with standard analytical results, and the relevance/advantages of each model are discussed. Numerical issues relevant to PIC codes such as resolution requirements, application of radiation reaction to macro particles and computational cost are also addressed. For parameters of interest where the classical description of the electron motion is applicable, all the models considered are shown to give comparable results. The Landau and Lifshitz reduced model is chosen for implementation as one of the candidates with the minimal overhead and no additional memory requirements.

  7. Effects of NOX1 on fibroblastic changes of endothelial cells in radiation-induced pulmonary fibrosis

    Science.gov (United States)

    CHOI, SEO-HYUN; KIM, MISEON; LEE, HAE-JUNE; KIM, EUN-HO; KIM, CHUN-HO; LEE, YOON-JIN

    2016-01-01

    Lung fibrosis is a major complication in radiation-induced lung damage following thoracic radiotherapy, while the underlying mechanism has remained to be elucidated. The present study performed immunofluorescence and immunoblot assays on irradiated human pulmonary artery endothelial cells (HPAECs) with or without pre-treatment with VAS2870, a novel NADPH oxidase (NOX) inhibitor, or small hairpin (sh)RNA against NOX1, -2 or -4. VAS2870 reduced the cellular reactive oxygen species content induced by 5 Gy radiation in HPAECs and inhibited phenotypic changes in fibrotic cells, including increased alpha smooth muscle actin and vimentin, and decreased CD31 and vascular endothelial cadherin expression. These fibrotic changes were significantly inhibited by treatment with NOX1 shRNA, but not by NOX2 or NOX4 shRNA. Next, the role of NOX1 in pulmonary fibrosis development was assessed in the lung tissues of C57BL/6J mice following thoracic irradiation using trichrome staining. Administration of an NOX1-specific inhibitor suppressed radiation-induced collagen deposition and fibroblastic changes in the endothelial cells (ECs) of these mice. The results suggested that radiation-induced pulmonary fibrosis may be efficiently reduced by specific inhibition of NOX1, an effect mediated by reduction of fibrotic changes of ECs. PMID:27053172

  8. Enhancement of radiation response in human hepatocarcinoma cells by Metformin

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Ho; Kim, Won Woo; Kim, Joon; Jung, Won Gyun [Division of heavy ion clinical research, Korea University, Seoul (Korea, Republic of); Jeong, Jae Hoon; Jeong, Youn Kyoung; Kim, Mi Sook [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2012-11-15

    Metformin (1, 1-dimethylbiguanide hydrochloride), the most widely used drug to treat type 2 diabetic patients under benefit good tolerability profile and low cost, has sparked keen interest as potential anticancer agent. Preclinical studies showed that the primary mechanism of action of metformin is through its ability to activate AMP-activated protein kinase (AMPK). Metformin inhibits complex 1 in the mitochondrial electron transport chain, leading to an increase in the AMP-to-ATP ratio, then, phospholylated AMPK increase energy generation or suppress energy consumption and then, inhibits cell growth. However, important caveat in direct action theory of metformin is that millimorlar range, effective dose for inhibition tumor cell growth in vitro, cannot be achieved in patients. This is probably because metformin enter cells through the organic cation transporters OCT1 and OCT2, which is lowly expressed in human cells except liver and adipose cells. dependent pathway rather than through direct effects of the tumor cells. We analyzed combination effect of metformin and radiation focusing to HCC cell lines, which theoretically express high organic cation transporters, producing high centration of metformin in tumor cells. The purpose of this study is to investigate whether metformin had anti-tumor effects when combined with radiation as radiosensitizer in HCC. The results showed that metformin increased radiosensitizing efficacy in HCC cells , as well as in Huh7 xenograft mouse models. Interestingly, metformin effectively sensitizes IR-induced apoptosis in HCC through upregulation of cleaved PARP and caspase3 and increase synergically on DNA damage response with combined treatment.HCC, suggesting potential usefulness of combined therapy of metformin together with radiation for HCC cancer therapy.

  9. Characterization of UV radiation sensitive frog cell lines

    International Nuclear Information System (INIS)

    Twenty-one subclones of nine frog cell isolates were tested for sensitivity to a panel of DNA damaging agents. Two clones were identified which had a greater than wild type level of sensitivity to UV radiation but had a wild type level of sensitivity to the other agents. These clones were the haploid RRP602-7 and the diploid RRP802-1. RRP802-1 was found to be unstable with respect to UV sensitivity. The line was cloned in order to isolate stable sensitive and wild type derivatives. RRP802-1-16, a UV sensitive clone and RRP802-1-13, a clone with a wild type level of sensitivity to UV radiation, were isolated. The UV radiation sensitivity of RRP602-7, RRP802-1 and RRP802-1-16 did not correlate with cell size, cell shape, cell cycle distribution or ploidy. The cell cycle distribution after UV irradiation, the rate of DNA synthesis after UV-irradiation, the DNA polymerase α activity and the sister chromatid exchange frequency were all measured in RRP602-7, RRP802-1 and RRP802-1-16 in order to examine the DNA repair capacity. The presence of DNA repair pathways was examined directly in RRP602-7, RRP802-1 and RRP802-1-16. All were found to be proficient in photo-reactivation repair and postreplication repair of UV elicited DNA damage

  10. Photoluminescence in large fluence radiation irradiated space silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hisamatsu, Tadashi; Kawasaki, Osamu; Matsuda, Sumio [National Space Development Agency of Japan, Tsukuba, Ibaraki (Japan). Tsukuba Space Center; Tsukamoto, Kazuyoshi

    1997-03-01

    Photoluminescence spectroscopy measurements were carried out for silicon 50{mu}m BSFR space solar cells irradiated with 1MeV electrons with a fluence exceeding 1 x 10{sup 16} e/cm{sup 2} and 10MeV protons with a fluence exceeding 1 x 10{sup 13} p/cm{sup 2}. The results were compared with the previous result performed in a relative low fluence region, and the radiation-induced defects which cause anomalous degradation of the cell performance in such large fluence regions were discussed. As far as we know, this is the first report which presents the PL measurement results at 4.2K of the large fluence radiation irradiated silicon solar cells. (author)

  11. Practice specific model regulations: Radiation safety of non-medical irradiation facilities. Interim report for comment

    International Nuclear Information System (INIS)

    the infrastructure aimed at achieving its maximum efficiency, and extensively covers performance regulations. The BSS cover the application of ionizing radiation for all practices and interventions and are, therefore, basic and general in nature. Users must apply these basic requirements to their own particular practices. In this context, the preamble of the BSS states that: 'The Regulatory Authority may need to provide guidance on how certain regulatory requirements are to be fulfilled for various practices, for example in regulatory guideline documents.' There are certain requirements that, when applied to specific practices, can be fulfilled through virtually only one practical solution. In these cases, the regulatory authority would use a 'shall' statement for this solution. To meet other requirements, there may be more than one option. In these cases the regulatory authority would usually indicate the recommended option with a 'should' statement, which implies that licensees may choose another alternative provided that the level of safety is equivalent. This distinction has been maintained in this 'model regulations' for irradiation facilities in order to facilitate the decision of regulatory authorities on the degree of obligation

  12. Dichloroacetate induces tumor-specific radiosensitivity in vitro but attenuates radiation-induced tumor growth delay in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Zwicker, F.; Roeder, F.; Debus, J.; Huber, P.E. [University Hospital Center Heidelberg, Heidelberg (Germany). Dept. of Radiation Oncology; Deutsches Krebsforschungszentrum (DKFZ), Heidelberg (Germany). Clinical Cooperation Unit Molecular Radiation Oncology; Kirsner, A.; Weber, K.J. [University Hospital Center Heidelberg, Heidelberg (Germany). Dept. of Radiation Oncology; Peschke, P. [Deutsches Krebsforschungszentrum (DKFZ), Heidelberg (Germany). Clinical Cooperation Unit Molecular Radiation Oncology

    2013-08-15

    Background: Inhibition of pyruvate dehydrogenase kinase (PDK) by dichloroacetate (DCA) can shift tumor cell metabolism from anaerobic glycolysis to glucose oxidation, with activation of mitochondrial activity and chemotherapy-dependent apoptosis. In radiotherapy, DCA could thus potentially enhance the frequently moderate apoptotic response of cancer cells that results from their mitochondrial dysfunction. The aim of this study was to investigate tumor-specific radiosensitization by DCA in vitro and in a human tumor xenograft mouse model in vivo. Materials and methods: The interaction of DCA with photon beam radiation was investigated in the human tumor cell lines WIDR (colorectal) and LN18 (glioma), as well as in the human normal tissue cell lines HUVEC (endothelial), MRC5 (lung fibroblasts) and TK6 (lymphoblastoid). Apoptosis induction in vitro was assessed by DAPI staining and sub-G1 flow cytometry; cell survival was quantified by clonogenic assay. The effect of DCA in vivo was investigated in WIDR xenograft tumors growing subcutaneously on BALB/c-nu/nu mice, with and without fractionated irradiation. Histological examination included TUNEL and Ki67 staining for apoptosis and proliferation, respectively, as well as pinomidazole labeling for hypoxia. Results: DCA treatment led to decreased clonogenic survival and increased specific apoptosis rates in tumor cell lines (LN18, WIDR) but not in normal tissue cells (HUVEC, MRC5, TK6). However, this significant tumor-specific radiosensitization by DCA in vitro was not reflected by the situation in vivo: The growth suppression of WIDR xenograft tumors after irradiation was reduced upon additional DCA treatment (reflected by Ki67 expression levels), although early tumor cell apoptosis rates were significantly increased by DCA. This apparently paradoxical effect was accompanied by a marked DCA-dependent induction of hypoxia in tumor-tissue. Conclusion: DCA induced tumor-specific radiosensitization in vitro but not in vivo

  13. Cancer specificity of promoters of the genes controlling cell proliferation.

    Science.gov (United States)

    Kashkin, Kirill; Chernov, Igor; Stukacheva, Elena; Monastyrskaya, Galina; Uspenskaya, Natalya; Kopantzev, Eugene; Sverdlov, Eugene

    2015-02-01

    Violation of proliferation control is a common feature of cancer cells. We put forward the hypothesis that promoters of genes involved in the control of cell proliferation should possess intrinsic cancer specific activity. We cloned promoter regions of CDC6, POLD1, CKS1B, MCM2, and PLK1 genes into pGL3 reporter vector and studied their ability to drive heterologous gene expression in transfected cancer cells of different origin and in normal human fibroblasts. Each promoter was cloned in short (335-800 bp) and long (up to 2.3 kb) variants to cover probable location of core and whole promoter regulatory elements. Cloned promoters were significantly more active in cancer cells than in normal fibroblasts that may indicate their cancer specificity. Both versions of CDC6 promoters were shown to be most active while the activities of others were close to that of BIRC5 gene (survivin) gene promoter. Long and short variants of each cloned promoter demonstrated very similar cancer specificity with the exception of PLK1-long promoter that was substantially more specific than its short variant and other promoters under study. The data indicate that most of the important cis-regulatory transcription elements responsible for intrinsic cancer specificity are located in short variants of the promoters under study. CDC6 short promoter may serve as a promising candidate for transcription targeted cancer gene therapy.

  14. Radiation damage and annealing of amorphous silicon solar cells

    Science.gov (United States)

    Byvik, C. E.; Slemp, W. S.; Smith, B. T.; Buoncristiani, A. M.

    1984-01-01

    Amorphous silicon solar cells were irradiated with 1 MeV electrons at the Space Environmental Effects Laboratory of the NASA Langley Research Center. The cells accumulated a total fluence of 10 to the 14th, 10 to the 15th, and 10 to the 16th electrons per square centimeter and exhibited increasing degradation with each irradiation. This degradation was tracked by evaluating the I-V curves for AM0 illumination and the relative spectral response. The observed radiation damage was reversed following an anneal of the cells under vacuum at 200 C for 2 hours.

  15. Radiation enteropathy and leucocyte-endothelial cell reactions in a refined small bowel model

    Directory of Open Access Journals (Sweden)

    Osman Nadia

    2004-09-01

    Full Text Available Abstract Background Leucocyte recruitment and inflammation are key features of high dose radiation-induced tissue injury. The inflammatory response in the gut may be more pronounced following radiotherapy due to its high bacterial load in comparison to the response in other organs. We designed a model to enable us to study the effects of radiation on leucocyte-endothelium interactions and on intestinal microflora in the murine ileum. This model enables us to study specifically the local effects of radiation therapy. Method A midline laparotomy was performed in male C57/Bl6 mice and a five-centimetre segment of ileum is irradiated using the chamber. Leucocyte responses (rolling and adhesion were then analysed in ileal venules 2 – 48 hours after high dose irradiation, made possible by an inverted approach using intravital fluorescence microscopy. Furthermore, intestinal microflora, myeloperoxidase (MPO and cell histology were analysed. Results The highest and most reproducible increase in leucocyte rolling was exhibited 2 hours after high dose irradiation whereas leucocyte adhesion was greatest after 16 hours. Radiation reduced the intestinal microflora count compared to sham animals with a significant decrease in the aerobic count after 2 hours of radiation. Further, the total aerobic counts, Enterobacteriaceae and Lactobacillus decreased significantly after 16 hours. In the radiation groups, the bacterial count showed a progressive increase from 2 to 24 hours after radiation. Conclusion This study presents a refinement of a previous method of examining mechanisms of radiation enteropathy, and a new approach at investigating radiation induced leucocyte responses in the ileal microcirculation. Radiation induced maximum leucocyte rolling at 2 hours and adhesion peaked at 16 hours. It also reduces the microflora count, which then starts to increase steadily afterwards. This model may be instrumental in developing strategies against pathological

  16. Investigating Striatal Function through Cell-Type-Specific Manipulations

    OpenAIRE

    Kreitzer, Anatol C.; Berke, Joshua D.

    2011-01-01

    The striatum integrates convergent input from the cortex, thalamus, and midbrain, and has a powerful influence over motivated behavior via outputs to downstream basal ganglia nuclei. Although the anatomy and physiology of distinct classes of striatal neurons has been intensively studied, the specific functions of these cell subpopulations have been more difficult to address. Recently, application of new methodologies for perturbing activity and signaling in different cell types in vivo has be...

  17. T-cell regulatory mechanisms in specific immunotherapy.

    Science.gov (United States)

    Jutel, Marek; Akdis, Cezmi A

    2008-01-01

    Allergen-specific immunotherapy (SIT) is the only treatment which leads to a lifelong tolerance against previously disease-causing allergens due to restoration of normal immunity against allergens. The description of T-regulatory (Treg) cells being involved in prevention of sensitization to allergens has led to great interest whether they represent a major target for allergen-SIT and whether it would be possible to manipulate Treg cells to increase its efficacy. Activationinduced cell death, anergy and/or immune response modulation by Treg cells are essential mechanisms of peripheral T-cell tolerance. There is growing evidence that anergy, tolerance and active suppression are not entirely distinct, but rather represent linked mechanisms possibly involving the same cells and multiple suppressor mechanisms. Skewing of allergen-specific effector T cells to Treg cells appears as a crucial event in the control of healthy immune response to allergens and successful allergen-SIT. The Treg cell response is characterized by abolished allergen- induced specific T-cell proliferation and suppressed Thelper (Th)1- and Th2-type cytokine secretion. In addition, mediators of allergic inflammation that trigger cAMP-associated G-protein-coupled receptors, such as histamine receptor-2, may contribute to peripheral tolerance mechanisms. The increased levels of interleukin-10 and transforming growth factor-Beta that are produced by Treg cells potently suppress IgE production, while simultaneously increasing production of non-inflammatory isotypes IgG4 and IgA, respectively. In addition, Treg cells directly or indirectly suppress effector cells of allergic inflammation such as mast cells, basophils and eosinophils. In conclusion, peripheral tolerance to allergens is controlled by multiple active suppression mechanisms. It is associated with regulation of antibody isotypes and effector cells to the direction of a healthy immune response. By the application of the recent knowledge in Treg

  18. Dissection of T-cell antigen specificity in human melanoma

    DEFF Research Database (Denmark)

    Andersen, Rikke Sick; Albæk Thrue, Charlotte; Junker, Niels;

    2012-01-01

    Tumor-infiltrating lymphocytes (TIL) isolated from melanoma patients and expanded in vitro by interleukin (IL)-2 treatment can elicit therapeutic response after adoptive transfer, but the antigen specificities of the T cells transferred have not been determined. By compiling all known melanoma-as...... from different fragments of resected melanoma lesions. In summary, our findings provide an initial definition of T-cell populations contributing to tumor recognition in TILs although the specificity of many tumor-reactive TILs remains undefined.......Tumor-infiltrating lymphocytes (TIL) isolated from melanoma patients and expanded in vitro by interleukin (IL)-2 treatment can elicit therapeutic response after adoptive transfer, but the antigen specificities of the T cells transferred have not been determined. By compiling all known melanoma......-associated antigens and applying a novel technology for high-throughput analysis of T-cell responses, we dissected the composition of melanoma-restricted T-cell responses in 63 TIL cultures. T-cell reactivity screens against 175 melanoma-associated epitopes detected 90 responses against 18 different epitopes...

  19. Mesenchymal Stem Cells Retain Their Defining Stem Cell Characteristics After Exposure to Ionizing Radiation

    International Nuclear Information System (INIS)

    Purpose: Mesenchymal stem cells (MSCs) have the ability to migrate to lesion sites and undergo differentiation into functional tissues. Although this function may be important for tissue regeneration after radiation therapy, the influence of ionizing radiation (IR) on cellular survival and the functional aspects of differentiation and stem cell characteristics of MSCs have remained largely unknown. Methods and Materials: Radiation sensitivity of human primary MSCs from healthy volunteers and primary human fibroblast cells was examined, and cellular morphology, cell cycle effects, apoptosis, and differentiation potential after exposure to IR were assessed. Stem cell gene expression patterns after exposure to IR were studied using gene arrays. Results: MSCs were not more radiosensitive than human primary fibroblasts, whereas there were considerable differences regarding radiation sensitivity within individual MSCs. Cellular morphology, cytoskeletal architecture, and cell motility were not markedly altered by IR. Even after high radiation doses up to 10 Gy, MSCs maintained their differentiation potential. Compared to primary fibroblast cells, MSCs did not show an increase in irradiation-induced apoptosis. Gene expression analyses revealed an upregulation of various genes involved in DNA damage response and DNA repair, but expression of established MSC surface markers appeared only marginally influenced by IR. Conclusions: These data suggest that human MSCs are not more radiosensitive than differentiated primary fibroblasts. In addition, upon photon irradiation, MSCs were able to retain their defining stem cell characteristics both on a functional level and regarding stem cell marker expression

  20. Mesenchymal Stem Cells Retain Their Defining Stem Cell Characteristics After Exposure to Ionizing Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Nicolay, Nils H., E-mail: n.nicolay@dkfz.de [Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg (Germany); Department of Molecular and Radiation Oncology, German Cancer Research Center, Heidelberg (Germany); Sommer, Eva; Lopez, Ramon; Wirkner, Ute [Department of Molecular and Radiation Oncology, German Cancer Research Center, Heidelberg (Germany); Trinh, Thuy [Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg (Germany); Department of Molecular and Radiation Oncology, German Cancer Research Center, Heidelberg (Germany); Sisombath, Sonevisay [Department of Molecular and Radiation Oncology, German Cancer Research Center, Heidelberg (Germany); Debus, Jürgen [Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg (Germany); Ho, Anthony D.; Saffrich, Rainer [Department of Hematology and Oncology, Heidelberg University Hospital, Heidelberg (Germany); Huber, Peter E. [Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg (Germany); Department of Molecular and Radiation Oncology, German Cancer Research Center, Heidelberg (Germany)

    2013-12-01

    Purpose: Mesenchymal stem cells (MSCs) have the ability to migrate to lesion sites and undergo differentiation into functional tissues. Although this function may be important for tissue regeneration after radiation therapy, the influence of ionizing radiation (IR) on cellular survival and the functional aspects of differentiation and stem cell characteristics of MSCs have remained largely unknown. Methods and Materials: Radiation sensitivity of human primary MSCs from healthy volunteers and primary human fibroblast cells was examined, and cellular morphology, cell cycle effects, apoptosis, and differentiation potential after exposure to IR were assessed. Stem cell gene expression patterns after exposure to IR were studied using gene arrays. Results: MSCs were not more radiosensitive than human primary fibroblasts, whereas there were considerable differences regarding radiation sensitivity within individual MSCs. Cellular morphology, cytoskeletal architecture, and cell motility were not markedly altered by IR. Even after high radiation doses up to 10 Gy, MSCs maintained their differentiation potential. Compared to primary fibroblast cells, MSCs did not show an increase in irradiation-induced apoptosis. Gene expression analyses revealed an upregulation of various genes involved in DNA damage response and DNA repair, but expression of established MSC surface markers appeared only marginally influenced by IR. Conclusions: These data suggest that human MSCs are not more radiosensitive than differentiated primary fibroblasts. In addition, upon photon irradiation, MSCs were able to retain their defining stem cell characteristics both on a functional level and regarding stem cell marker expression.

  1. Simulation of TGF-Beta Activation by Low-Dose HZE Radiation in a Cell Culture

    Science.gov (United States)

    Plante, Ianik; Cucinotta, Francis A.

    2009-01-01

    High charge (Z) and energy (E) (HZE) nuclei comprised in the galactic cosmic rays are main contributors to space radiation risk. They induce many lesions in living matter such as non-specific oxidative damage and the double-strand breaks (DSBs), which are considered key precursors of early and late effects of radiation. There is increasing evidence that cells respond collectively rather than individually to radiation, suggesting the importance of cell signaling1. The transforming growth factor (TGF ) is a signaling peptide that is expressed in nearly all cell type and regulates a large array of cellular processes2. TGF have been shown to mediate cellular response to DNA damage3 and to induce apoptosis in non-irradiated cells cocultured with irradiated cells4. TFG molecules are secreted by cells in an inactive complex known as the latency-associated peptide (LAP). TGF is released from the LAP by a conformational change triggered by proteases, thrombospondin-1, integrins, acidic conditions and .OH radical5. TGF then binds to cells receptors and activates a cascade of events mediated by Smad proteins6, which might interfere with the repair of DNA. Meanwhile, increasingly sophisticated Brownian Dynamics (BD) algorithms have appeared recently in the literature7 and can be applied to study the interaction of molecules with receptors. These BD computer models have contributed to the elucidation of signal transduction, ligand accumulation and autocrine loops in the epidermal growth factor (EGF) and its receptor (EFGR) system8. To investigate the possible roles of TGF in an irradiated cell culture, our Monte-Carlo simulation codes of the radiation track structure9 will be used to calculate the activation of TFG triggered by .OH produced by low doses of HZE ions. The TGF molecules will then be followed by a BD algorithm in a medium representative of a cell culture to estimate the number of activated receptors.

  2. Radiation Dose Effects into LCO in Technical Specification by Iodine in Hanul units 1,2

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hye Min; Lee, Seung Chan [KHNP Central Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    This study estimates the impact of the 1-th coolant system in NPP to the LCO (Limiting Condition of Operation) limits which is in the site boundary. Dose limit is merged into the effective dose from whole body and thyroid dose limits, that is possible to combine the two LCOs to a unified LCO. To estimate the limits, the radiation dose of one of the designed accidents should be chosen to check the radiation dose response. The selected accident is based on Seung Chan Lee's study at KHNP in 2011. Using the selected accident, Iodine dose effect is reviewed depending on the LCO limiting responsibility and the specific behavior. In order to evaluate the radiation dose effect in Technical Specification of Hanul 1,2, SGTR is selected for some sensitivity analysis. From the results, in Hanul site, the case of LOOP plus ADV plus GIS is the most severe case and the dose limit margin is about 110% in LCO.

  3. The role of constitutive and inducible processes in the response of human squamous cell carcinoma cell lines to ionizing radiation

    International Nuclear Information System (INIS)

    The inherent radiation sensitivity of the cells within a tumor is thought to contribute to the success or failure of radiation therapy. In vitro studies have shown that differences in the radiation sensitivity of squamous cell carcinoma cell lines reflect alterations in DNA repair. These alterations result from constitutive changes in chromosome organization, not radiation-inducible processes. While inducible responses may play some role in the radiation response of tumor cells, there is no evidence for their involvement in inherent differences in tumor cell radiosensitivity or in the success or failure of radiotherapy of squamous cell carcinomas. 21 refs., 1 fig., 1 tab

  4. Specific Protein Markers for Stem Cell Cross-Talk with Neighboring Cells in the Environment

    OpenAIRE

    Park, Kyung Soo; Shin, Seung Won; Choi, Jeong-Woo; Um, Soong Ho

    2013-01-01

    A stem cell interacts with the neighboring cells in its environment. To maintain a living organism’s metabolism, either cell-cell or cell-environment interactions may be significant. Usually, these cells communicate with each other through biological signaling by interactive behaviors of primary proteins or complementary chemicals. The signaling intermediates offer the stem cell’s functionality on its metabolism. With the rapid advent of omics technologies, various specific markers by which s...

  5. Radiation response characteristics of human cell in vitro

    International Nuclear Information System (INIS)

    Improvements in tissue culture techniques and growth media have made it possible to culture a range of cells of human origin, both normal and malignant. The most recent addition to the list are endothelial cells. Interesting results have been obtained, some of which may have implications in Radiation Therapy. (i) Repair of Potentially Lethal Damage (PLDR) has been observed in all cell lines investigated; cells of normal origin repair PLD at least as well as malignant cells, which makes clinical trials of PLDR inhibitors of doubtful usefulness. (ii) PLD in fibroblasts of human origin appears to have a component that is repaired rapidly, in a matter of minutes, as well as a slower component that takes hours to repair. (iii) Sublethal damage repair, manifest by a dose-rate effect, has also been observed in all human cell lines tested. Cells of normal tissue origin, including fibroblasts and endothelial cells, exhibit a dose-rate effect that is intermediate between that for cells from traditionally resistant tumors (melanoma and osteosarcoma) and cells from more sensitive tumors (neuroblastoma and breast). (iv) Fibroblasts from patients with Ataxia Telangectasia (AT) are much more sensitive to x-rays, with a D/sub o/ about half that for normal human fibroblasts. Nevertheless repair of both PLD and SLD can be demonstrated in these cells

  6. Neuropeptides, via specific receptors, regulate T cell adhesion to fibronectin.

    Science.gov (United States)

    Levite, M; Cahalon, L; Hershkoviz, R; Steinman, L; Lider, O

    1998-01-15

    The ability of T cells to adhere to and interact with components of the blood vessel walls and the extracellular matrix is essential for their extravasation and migration into inflamed sites. We have found that the beta1 integrin-mediated adhesion of resting human T cells to fibronectin, a major glycoprotein component of the extracellular matrix, is induced by physiologic concentrations of three neuropeptides: calcitonin gene-related protein (CGRP), neuropeptide Y, and somatostatin; each acts via its own specific receptor on the T cell membrane. In contrast, substance P (SP), which coexists with CGRP in the majority of peripheral endings of sensory nerves, including those innervating the lymphoid organs, blocks T cell adhesion to fibronectin when induced by CGRP, neuropeptide Y, somatostatin, macrophage inflammatory protein-1beta, and PMA. Inhibition of T cell adhesion was obtained both by the intact SP peptide and by its 1-4 N-terminal and its 4-11, 5-11, and 6-11 C-terminal fragments, used at similar nanomolar concentrations. The inhibitory effects of the parent SP peptide and its fragments were abrogated by an SP NK-1 receptor antagonist, suggesting they all act through the same SP NK-1 receptor. These findings suggest that neuropeptides, by activating their specific T cell-expressed receptors, can provide the T cells with both positive (proadhesive) and negative (antiadhesive) signals and thereby regulate their function. Thus, neuropeptides may influence diverse physiologic processes involving integrins, including leukocyte-mediated migration and inflammation. PMID:9551939

  7. Optimization Manufacture of Virus- and Tumor-Specific T Cells

    Directory of Open Access Journals (Sweden)

    Natalia Lapteva

    2011-01-01

    Full Text Available Although ex vivo expanded T cells are currently widely used in pre-clinical and clinical trials, the complexity of manufacture remains a major impediment for broader application. In this review we discuss current protocols for the ex vivo expansion of virus- and tumor-specific T cells and describe our experience in manufacture optimization using a gas-permeable static culture flask (G-Rex. This innovative device has revolutionized the manufacture process by allowing us to increase cell yields while decreasing the frequency of cell manipulation and in vitro culture time. It is now being used in good manufacturing practice (GMP facilities for clinical cell production in our institution as well as many others in the US and worldwide.

  8. Radiation-responsive transcriptome analysis in human lymphoid cells

    International Nuclear Information System (INIS)

    Ionising radiation (IR) causes DNA (deoxyribonucleic acid) injury and activates intracellular signal pathways including the regulation of DNA repair and cell cycle. However, the further knowledge of molecular events involved in radiation exposure is essential to more comprehensively understand the effects of irradiation. Therefore, the gene expressions of mRNA (messenger ribonucleic acid) by X-ray irradiation in human B lymphoblasts cell line (IM-9) using a microarray were investigated. The mRNA expressions of 65 genes were shown to be up-regulated at >2.0-fold in irradiated cells (4 Gy) when compared with non-irradiated cells (0 Gy) by microarray analysis. Among 65 genes, a large number of genes were up-regulated with an X-ray dose-dependent change. These results indicate that the up-regulation of their mRNAs is the effects of irradiation and may be due to biological dosimetric markers for the evaluation of radiation exposure in the future. (authors)

  9. Mechanisms underlying cellular responses of cells from haemopoietic tissue to low dose/low LET radiation

    Energy Technology Data Exchange (ETDEWEB)

    Munira A Kadhim

    2010-03-05

    To accurately define the risks associated with human exposure to relevant environmental doses of low LET ionizing radiation, it is necessary to completely understand the biological effects at very low doses (i.e., less than 0.1 Gy), including the lowest possible dose, that of a single electron track traversal. At such low doses, a range of studies have shown responses in biological systems which are not related to the direct interaction of radiation tracks with DNA. The role of these “non-targeted” responses in critical tissues is poorly understood and little is known regarding the underlying mechanisms. Although critical for dosimetry and risk assessment, the role of individual genetic susceptibility in radiation risk is not satisfactorily defined at present. The aim of the proposed grant is to critically evaluate radiation-induced genomic instability and bystander responses in key stem cell populations from haemopoietic tissue. Using stem cells from two mouse strains (CBA/H and C57BL/6J) known to differ in their susceptibility to radiation effects, we plan to carefully dissect the role of genetic predisposition on two non-targeted radiation responses in these models; the bystander effect and genomic instability, which we believe are closely related. We will specifically focus on the effects of low doses of low LET radiation, down to doses approaching a single electron traversal. Using conventional X-ray and γ-ray sources, novel dish separation and targeted irradiation approaches, we will be able to assess the role of genetic variation under various bystander conditions at doses down to a few electron tracks. Irradiations will be carried out using facilities in routine operation for bystander targeted studies. Mechanistic studies of instability and the bystander response in different cell lineages will focus initially on the role of cytokines which have been shown to be involved in bystander signaling and the initiation of instability. These studies also aim

  10. Time-specific measurements of energy deposition from radiation fields in simulated sub-micron tissue volumes

    Energy Technology Data Exchange (ETDEWEB)

    Famiano, M.A.

    1997-07-07

    A tissue-equivalent spherical proportional counter is used with a modified amplifier system to measure specific energy deposited from a uniform radiation field for short periods of time ({approximately}1 {micro}s to seconds) in order to extrapolate to dose in sub-micron tissue volumes. The energy deposited during these time intervals is compared to biological repair processes occurring within the same intervals after the initial energy deposition. The signal is integrated over a variable collection time which is adjusted with a square-wave pulse. Charge from particle passages is collected on the anode during the period in which the integrator is triggered, and the signal decays quickly to zero after the integrator feedback switch resets; the process repeats for every triggering pulse. Measurements of energy deposited from x rays, {sup 137}Cs gamma rays, and electrons from a {sup 90}Sr/{sup 90}Y source for various time intervals are taken. Spectral characteristics as a function of charge collection time are observed and frequency plots of specific energy and collection time-interval are presented. In addition, a threshold energy flux is selected for each radiation type at which the formation of radicals (based on current measurements) in mammalian cells equals the rate at which radicals are repaired.

  11. Time-specific measurements of energy deposition from radiation fields in simulated sub-micron tissue volumes

    International Nuclear Information System (INIS)

    A tissue-equivalent spherical proportional counter is used with a modified amplifier system to measure specific energy deposited from a uniform radiation field for short periods of time (∼1 micros to seconds) in order to extrapolate to dose in sub-micron tissue volumes. The energy deposited during these time intervals is compared to biological repair processes occurring within the same intervals after the initial energy deposition. The signal is integrated over a variable collection time which is adjusted with a square-wave pulse. Charge from particle passages is collected on the anode during the period in which the integrator is triggered, and the signal decays quickly to zero after the integrator feedback switch resets; the process repeats for every triggering pulse. Measurements of energy deposited from x rays, 137Cs gamma rays, and electrons from a 90Sr/90Y source for various time intervals are taken. Spectral characteristics as a function of charge collection time are observed and frequency plots of specific energy and collection time-interval are presented. In addition, a threshold energy flux is selected for each radiation type at which the formation of radicals (based on current measurements) in mammalian cells equals the rate at which radicals are repaired

  12. Acetylation site specificities of lysine deacetylase inhibitors in human cells

    DEFF Research Database (Denmark)

    Schölz, Christian; Weinert, Brian Tate; Wagner, Sebastian A;

    2015-01-01

    Lysine deacetylases inhibitors (KDACIs) are used in basic research, and many are being investigated in clinical trials for treatment of cancer and other diseases. However, their specificities in cells are incompletely characterized. Here we used quantitative mass spectrometry (MS) to obtain acety...

  13. How much can we say about site-specific cancer radiation risks?

    Science.gov (United States)

    Preston, D L; Krestinina, L Yu; Sokolnikov, M E; Ron, E; Davis, F G; Ostroumova, E V; Gilbert, E S

    2010-12-01

    Studies of Mayak workers and people who lived along the Techa River have demonstrated significant associations between low-dose-rate radiation exposure and increased solid cancer risk. It is of interest to use the long-term follow-up data from these cohorts to describe radiation effects for specific types of cancer; however, statistical variability in the site-specific risk estimates is large. The goal of this work is to describe this variability and provide Bayesian adjusted risk estimates. We assume that the site-specific estimates can be viewed as a sample from some underlying distribution and use Bayesian methods to produce adjusted excess relative risk per gray estimates in the Mayak and Techa River cohorts. The impact of the adjustment is compared to that seen in similar analyses in the atomic bomb survivors. Site-specific risk estimates in the Mayak and Techa River cohorts have large uncertainties. Unadjusted estimates vary from implausibly large decreases to large increases, with a range that greatly exceeds that found in the A-bomb survivors. The Bayesian adjustment markedly reduced the range of the site-specific estimates for the Techa River and Mayak studies. The extreme variability in the site-specific risk estimates is largely a consequence of the small number of excess cases. The adjusted estimates provide a useful perspective on variation in the actual risks. However, additional work on interpretation of the adjusted estimates, extension of the methods used in describing effect modification, and making more use of prior knowledge is needed to make these methods useful. PMID:21128806

  14. CELL DETACHMENT BY PROLYL-SPECIFIC ENDOPEPTIDASE FROM WOLFIPORIA COCOS

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    Katharina Cierpka

    2014-01-01

    Full Text Available As requirements for Advanced Therapy Medicinal Product (ATMP production differ from other production processes (e.g., therapeutic protein production, cell detachment is often a crucial step for the process success. In most cases, cell detachment is done enzymatically. Although many peptidases are established in cell culture in R&D, e.g., Trypsin as gold standard, many of them seem to be unsuitable in ATMP production processes. Therefore, the present study investigated a novel endopeptidase used in food biotechnology for its applicability in ATMP processes where cell detachment is needed. The Prolyl-specific Peptidase (PsP is of non-mammalian origin and considered as safe for humans. PsP was purified from the supernatant of the fungus Wolfiporia cocos. The isolation and purification resulted in an enzyme solution with 0.19 U mg-1 prolyl-specific activity. By in silico analysis it was confirmed that attachment-promoting proteins can be cleaved by PsP in a similar amount than with Trypsin. Further the proteolytic activity was determined for PsP and Trypsin by using the same enzymatic assay. Detachment with both enzymes was compared for cells used in typical therapeutic production processes namely a mesenchymal stem cell line (hMSC-TERT as a model for a cell therapeutic, Vero and MA104 cells used for viral therapeutic or vaccine production. The cell detachment experiments were performed with comparable enzyme activities (1.6 U mL-1. hMSC-TERT detachment was faster with PsP than with Trypsin. For Vero cells the detachment with PsP was not only faster but also more efficient. For MA104 cells the detachment rate with PsP was similar to Trypsin. For all cell types, detachment with PsP showed less influence on cell growth and metabolism compared to standard Trypsin.Thus, three cell types used in ATMP, viral therapeutics or vaccine production can be detached efficiently and gently with PsP. Therefore, PsP shows

  15. Patient-Specific Pluripotent Stem Cells in Neurological Diseases

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    Serpen Durnaoglu

    2011-01-01

    Full Text Available Many human neurological diseases are not currently curable and result in devastating neurologic sequelae. The increasing availability of induced pluripotent stem cells (iPSCs derived from adult human somatic cells provides new prospects for cellreplacement strategies and disease-related basic research in a broad spectrum of human neurologic diseases. Patient-specific iPSC-based modeling of neurogenetic and neurodegenerative diseases is an emerging efficient tool for in vitro modeling to understand disease and to screen for genes and drugs that modify the disease process. With the exponential increase in iPSC research in recent years, human iPSCs have been successfully derived with different technologies and from various cell types. Although there remain a great deal to learn about patient-specific iPSC safety, the reprogramming mechanisms, better ways to direct a specific reprogramming, ideal cell source for cellular grafts, and the mechanisms by which transplanted stem cells lead to an enhanced functional recovery and structural reorganization, the discovery of the therapeutic potential of iPSCs offers new opportunities for the treatment of incurable neurologic diseases. However, iPSC-based therapeutic strategies need to be thoroughly evaluated in preclinical animal models of neurological diseases before they can be applied in a clinical setting.

  16. Cancer cell specific cytotoxic gene expression mediated by ARF tumor suppressor promoter constructs.

    Science.gov (United States)

    Kurayoshi, Kenta; Ozono, Eiko; Iwanaga, Ritsuko; Bradford, Andrew P; Komori, Hideyuki; Ohtani, Kiyoshi

    2014-07-18

    In current cancer treatment protocols, such as radiation and chemotherapy, side effects on normal cells are major obstacles to radical therapy. To avoid these side effects, a cancer cell-specific approach is needed. One way to specifically target cancer cells is to utilize a cancer specific promoter to express a cytotoxic gene (suicide gene therapy) or a viral gene required for viral replication (oncolytic virotherapy). For this purpose, the selected promoter should have minimal activity in normal cells to avoid side effects, and high activity in a wide variety of cancers to obtain optimal therapeutic efficacy. In contrast to the AFP, CEA and PSA promoters, which have high activity only in a limited spectrum of tumors, the E2F1 promoter exhibits high activity in wide variety of cancers. This is based on the mechanism of carcinogenesis. Defects in the RB pathway and activation of the transcription factor E2F, the main target of the RB pathway, are observed in almost all cancers. Consequently, the E2F1 promoter, which is mainly regulated by E2F, has high activity in wide variety of cancers. However, E2F is also activated by growth stimulation in normal growing cells, suggesting that the E2F1 promoter may also be highly active in normal growing cells. In contrast, we found that the tumor suppressor ARF promoter is activated by deregulated E2F activity, induced by forced inactivation of pRB, but does not respond to physiological E2F activity induced by growth stimulation. We also found that the deregulated E2F activity, which activates the ARF promoter, is detected only in cancer cell lines. These observations suggest that ARF promoter is activated by E2F only in cancer cells and therefore may be more cancer cell-specific than E2F1 promoter to drive gene expression. We show here that the ARF promoter has lower activity in normal growing fibroblasts and shows higher cancer cell-specificity compared to the E2F1 promoter. We also demonstrate that adenovirus expressing HSV

  17. Stem cell, cytokine and plastic surgical management for radiation injuries

    International Nuclear Information System (INIS)

    Increasing concern on systemic and local radiation injuries caused by nuclear power plant accident, therapeutic irradiation or nuclear terrorism should be treated and prevented properly for life-saving and improved wound management. We therefore reviewed our therapeutic regimens and for local radiation injuries and propose surgical methods reflecting the importance of the systemic and general conditions. For local radiation injuries, after careful and complete debridement, sequential surgeries with local flap, arterialized or perforator flap and to free flap are used when the patients' general conditions allow. Occasionally, undetermined wound margins in acute emergency radiation injuries and the regenerative surgical modalities should be attempted with temporal artificial dermis impregnated and sprayed with angiogenic factor such as basic fibroblast growth factor (bFGF) and secondary reconstruction can be a candidate for demarcation and saving the donor morbidity. Human mesenchymal stem cells (hMSCs) and adipose-derived stem cells (ADSCs), together with angiogenic and mitogenic factor of basic fibroblast growth factor (bFGF) and an artificial dermis were applied over the excised irradiated skin defect are tested for differentiation and local stimulation effects in the radiation-exposed wounds. The perforator flap and artificial dermal template with growth factor were successful for reconstruction in patients who are suffering from complex underlying disease. Patients were uneventfully treated with minimal morbidities. The hMSCs are strongly proliferative even after 20 Gy irradiation in vitro. Immediate artificial dermis application impregnated with hMSCs and bFGF over the 20 Gy irradiated skin and soft tissues demonstrated the significantly improved fat angio genesis, architected dermal reconstitution and less inflammatory epidermal recovery. Even though emergent cases are more often experienced, detailed understanding of underlying diseases and rational

  18. Radiation- and chemoinduced multidrug resistance in colon carcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Bartkowiak, Detlef; Stempfhuber, Michael; Wiegel, Thomas; Bottke, Dirk [Dept. of Radiotherapy and Radiooncology, Univ. of Ulm (Germany)

    2009-12-15

    Background and purpose: radiation can induce multidrug resistance (MDR) and thus interfere with simultaneous or subsequent chemotherapy. In SW620 colon carcinoma cells, the interrelation of various biological endpoints of MDR was analyzed and the potential of fractionated irradiation and chemoselection to evoke MDR was compared. Material and methods: to induce/select an MDR phenotype, SW620 were exposed to either 27 Gy in 1.8-Gy daily fractions or to 50% inhibiting concentrations of doxorubicin or cisplatin, given over 6-15 weeks. Expression of genes involved in MDR, including glutathione metabolism, was determined by semiquantitative RT-PCR (reverse transcription-polymerase chain reaction). Efflux was analyzed by flow cytometry after staining with rhodamine-123 or 5-chloromethyl fluorescein diacetate. Apoptosis was monitored after pulse exposure to doxorubicin or cisplatin. Colony-forming assays were performed under continuous drug exposure. Results: a pronounced gene induction was found in MRP2 after cisplatin selection and up to 3 weeks after radiation. LRP was activated only shortly after radiation. Radiation enhanced rhodamine-123 efflux to a similar extent as short-term chemoselection but not as much as long-term drug exposure. Drug-induced apoptosis was slightly delayed in preirradiated cells. Clonogenic growth in the progeny of irradiated cells was less sensitive to cisplatin but not to doxorubicin. Conclusion: fractionated radiation can induce an MDR phenotype in SW620. However, long-term drug exposure establishes a more efficient selection. Various endpoints are not fully concordant regarding the extent of MDR. Posttranscriptional modifications, pleiotropic regulation, and alternative pathways may cause these discrepancies. (orig.)

  19. Estimated Radiation on Mars, Hits per Cell Nucleus

    Science.gov (United States)

    2002-01-01

    This global map of Mars shows estimates for amounts of high-energy-particle cosmic radiation reaching the surface, a serious health concern for any future human exploration of the planet.The estimates are based on cosmic-radiation measurements made on the way to Mars by the Mars radiation environment experiment, an instrument on NASA's 2001 Mars Odyssey spacecraft, plus information about Mars' surface elevations from the laser altimeter instrument on NASA's Mars Global Surveyor. The areas of Mars expected to have least radiation are where elevation is lowest, because those areas have more atmosphere above them to block out some of the radiation. Earth's thick atmosphere shields us from most cosmic radiation, but Mars has a much thinner atmosphere than Earth does.Colors in the map refer to the estimated average number of times per year each cell nucleus in a human there would be hit by a high-energy cosmic ray particle. The range is generally from two hits (color-coded green), a moderate risk level, to eight hits (coded red), a high risk level.NASA's Jet Propulsion Laboratory, Pasadena, Calif. manages the 2001 Mars Odyssey and Mars Global Surveyor missions for NASA's Office of Space Science, Washington D.C. The Mars radiation environment experiment was developed by NASA's Johnson Space Center. Lockheed Martin Astronautics, Denver, is the prime contractor for Odyssey, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  20. High efficiency cell-specific targeting of cytokine activity

    Science.gov (United States)

    Garcin, Geneviève; Paul, Franciane; Staufenbiel, Markus; Bordat, Yann; van der Heyden, José; Wilmes, Stephan; Cartron, Guillaume; Apparailly, Florence; de Koker, Stefaan; Piehler, Jacob; Tavernier, Jan; Uzé, Gilles

    2014-01-01

    Systemic toxicity currently prevents exploiting the huge potential of many cytokines for medical applications. Here we present a novel strategy to engineer immunocytokines with very high targeting efficacies. The method lies in the use of mutants of toxic cytokines that markedly reduce their receptor-binding affinities, and that are thus rendered essentially inactive. Upon fusion to nanobodies specifically binding to marker proteins, activity of these cytokines is selectively restored for cell populations expressing this marker. This ‘activity-by-targeting’ concept was validated for type I interferons and leptin. In the case of interferon, activity can be directed to target cells in vitro and to selected cell populations in mice, with up to 1,000-fold increased specific activity. This targeting strategy holds promise to revitalize the clinical potential of many cytokines.

  1. Specification of region-specific neurons including forebrain glutamatergic neurons from human induced pluripotent stem cells.

    Directory of Open Access Journals (Sweden)

    Hui Zeng

    Full Text Available BACKGROUND: Directed differentiation of human induced pluripotent stem cells (hiPSC into functional, region-specific neural cells is a key step to realizing their therapeutic promise to treat various neural disorders, which awaits detailed elucidation. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed neural differentiation from various hiPSC lines generated by others and ourselves. Although heterogeneity in efficiency of neuroepithelial (NE cell differentiation was observed among different hiPSC lines, the NE differentiation process resembles that from human embryonic stem cells (hESC in morphology, timing, transcriptional profile, and requirement for FGF signaling. NE cells differentiated from hiPSC, like those from hESC, can also form rostral phenotypes by default, and form the midbrain or spinal progenitors upon caudalization by morphogens. The rostrocaudal neural progenitors can further mature to develop forebrain glutamatergic projection neurons, midbrain dopaminergic neurons, and spinal motor neurons, respectively. Typical ion channels and action potentials were recorded in the hiPSC-derived neurons. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that hiPSC, regardless of how they were derived, can differentiate into a spectrum of rostrocaudal neurons with functionality, which supports the considerable value of hiPSC for study and treatment of patient-specific neural disorders.

  2. Ionizing Radiation Exposure and Basal Cell Carcinoma Pathogenesis.

    Science.gov (United States)

    Li, Changzhao; Athar, Mohammad

    2016-03-01

    This commentary summarizes studies showing risk of basal cell carcinoma (BCC) development in relationship to environmental, occupational and therapeutic exposure to ionizing radiation (IR). BCC, the most common type of human cancer, is driven by the aberrant activation of hedgehog (Hh) signaling. Ptch, a tumor suppressor gene of Hh signaling pathway, and Smoothened play a key role in the development of radiation-induced BCCs in animal models. Epidemiological studies provide evidence that humans exposed to radiation as observed among the long-term, large scale cohorts of atomic bomb survivors, bone marrow transplant recipients, patients with tinea capitis and radiologic workers enhances risk of BCCs. Overall, this risk is higher in Caucasians than other races. People who were exposed early in life develop more BCCs. The enhanced IR correlation with BCC and not other common cutaneous malignancies is intriguing. The mechanism underlying these observations remains undefined. Understanding interactions between radiation-induced signaling pathways and those which drive BCC development may be important in unraveling the mechanism associated with this enhanced risk. Recent studies showed that Vismodegib, a Smoothened inhibitor, is effective in treating radiation-induced BCCs in humans, suggesting that common strategies are required for the intervention of BCCs development irrespective of their etiology. PMID:26930381

  3. Circadian control of antigen-specific T cell responses

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    Nobis CC

    2016-09-01

    Full Text Available Chloé C Nobis,1–3 Nathalie Labrecque,2–4 Nicolas Cermakian1,5–8 1Douglas Mental Health University Institute, 2Maisonneuve-Rosemont Hospital Research Centre, 3Department of Microbiology, Infectious Diseases and Immunology, 4Department of Medicine, University of Montreal, 5Department of Psychiatry, 6Department of Microbiology and Immunology, 7Department of Neurology and Neurosurgery, 8Department of Physiology, McGill University, Montreal, QC, Canada Abstract: The immune system is composed of two arms, the innate and the adaptive immunity. While the innate response constitutes the first line of defense and is not specific for a particular pathogen, the adaptive response is highly specific and allows for long-term memory of the pathogen encounter. T lymphocytes (or T cells are central players in the adaptive immune response. Various aspects of T cell functions vary according to the time of day. Circadian clocks located in most tissues and cell types generate 24-hour rhythms of various physiological processes. These clocks are based on a set of clock genes, and this timing mechanism controls rhythmically the expression of numerous other genes. Clock genes are expressed in cells of the immune system, including T cells. In this review, we provide an overview of the circadian control of the adaptive immune response, with emphasis on T cells, including their development, trafficking, response to antigen, and effector functions. Keywords: circadian clock, adaptive immune response, T lymphocyte, antigen, cytokine, proliferation

  4. From radiation-induced chromosome damage to cell death: modelling basic mechanisms and applications to boron neutron capture therapy.

    Science.gov (United States)

    Ballarini, F; Bortolussi, S; Clerici, A M; Ferrari, C; Protti, N; Altieri, S

    2011-02-01

    Cell death is a crucial endpoint in radiation-induced biological damage: on one side, cell death is a reference endpoint to characterise the action of radiation in biological targets; on the other side, any cancer therapy aims to kill tumour cells. Starting from Lea's target theory, many models have been proposed to interpret radiation-induced cell killing; after briefly discussing some of these models, in this paper, a mechanistic approach based on an experimentally observed link between chromosome aberrations and cell death was presented. More specifically, a model and a Monte Carlo code originally developed for chromosome aberrations were extended to simulate radiation-induced cell death applying an experimentally observed one-to-one relationship between the average number of 'lethal aberrations' (dicentrics, rings and deletions) per cell and -ln S, S being the fraction of surviving cells. Although such observation was related to X rays, in the present work, the approach was also applied to protons and alpha particles. A good agreement between simulation outcomes and literature data provided a model validation for different radiation types. The same approach was then successfully applied to simulate the survival of cells enriched with boron and irradiated with thermal neutrons at the Triga Mark II reactor in Pavia, to mimic a typical treatment for boron neutron capture therapy. PMID:21159746

  5. Tinnitus and cell phones: the role of electromagnetic radiofrequency radiation

    OpenAIRE

    Luisa Nascimento Medeiros; Tanit Ganz Sanchez

    2016-01-01

    ABSTRACT INTRODUCTION: Tinnitus is a multifactorial condition and its prevalence has increased on the past decades. The worldwide progressive increase of the use of cell phones has exposed the peripheral auditory pathways to a higher dose of electromagnetic radiofrequency radiation (EMRFR). Some tinnitus patients report that the abusive use of mobiles, especially when repeated in the same ear, might worsen ipsilateral tinnitus. OBJECTIVE: The aim of this study was to evaluate the availabl...

  6. Dendritic Cells Coordinate the Development and Homeostasis of Organ-Specific Regulatory T Cells.

    Science.gov (United States)

    Leventhal, Daniel S; Gilmore, Dana C; Berger, Julian M; Nishi, Saki; Lee, Victoria; Malchow, Sven; Kline, Douglas E; Kline, Justin; Vander Griend, Donald J; Huang, Haochu; Socci, Nicholas D; Savage, Peter A

    2016-04-19

    Although antigen recognition mediated by the T cell receptor (TCR) influences many facets of Foxp3(+) regulatory T (Treg) cell biology, including development and function, the cell types that present antigen to Treg cells in vivo remain largely undefined. By tracking a clonal population of Aire-dependent, prostate-specific Treg cells in mice, we demonstrated an essential role for dendritic cells (DCs) in regulating organ-specific Treg cell biology. We have shown that the thymic development of prostate-specific Treg cells required antigen presentation by DCs. Moreover, Batf3-dependent CD8α(+) DCs were dispensable for the development of this clonotype and had negligible impact on the polyclonal Treg cell repertoire. In the periphery, CCR7-dependent migratory DCs coordinated the activation of organ-specific Treg cells in the prostate-draining lymph nodes. Our results demonstrate that the development and peripheral regulation of organ-specific Treg cells are dependent on antigen presentation by DCs, implicating DCs as key mediators of organ-specific immune tolerance.

  7. Investigation of bias radiation effect on PV cell measurement

    Science.gov (United States)

    Huang, Xuebo; Quan, Chenggen; Chan, Joanne; Ng, Patrick

    2013-06-01

    Photovoltaic (PV) cells are photo-electrical devices that convert light energy directly into electricity through the photovoltaic effect. PV cell assemblies are used to make solar modules employed in a variety of ways ranging from space applications to domestic energy consumption. Characterisation and performance testing of PV cells are critical to the development of PV technologies and growth of the solar industry. As new solar products are being developed, its energy conversion efficiency and other critical parameters must be accurately measured and tested against globally recognised metrological standards. The differential spectral responsivity (DSR) measurement is one of the primary methods for calibrating reference PV cells. This is done by calculating its spectral responsivities through measuring the AC short-circuit current produced by a PV cell under a modulated monochromatic radiation and different levels of steady-state broadband bias light radiation. It is observed that different types of bias light source will produce different signal-to-noise levels and significantly influence measurement accuracy. This paper aims to investigate the noise sources caused by different types of bias light sources (e.g. xenon arc and tungsten-halogen lamps) and the relevant measurement uncertainties so as to propose a guideline for selection of bias light source which can improve the signal-to-noise level and measurement uncertainty. The DSRs of the PV cells are measured using a commercial DSR measurement system under different levels of bias radiation from 0 to 1 kWm-2. The data analysis and uncertainty evaluation are presented in this paper using experimental data and mathematical tools.

  8. Regulatory mechanism of radiation-induced cancer cell death by the change of cell cycle

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Soo Jin; Jeong, Min Ho; Jang, Ji Yeon [College of Medicine, Donga Univ., Pusan (Korea, Republic of)

    2003-09-01

    In our previous study, we have shown the main cell death pattern induced by irradiation or protein tyrosine kinase (PTK) inhibitors in K562 human myelogenous leukemic cell line. Death of the cells treated with irradiation alone was characterized by mitotic catastrophe and typical radiation-induced apoptosis was accelerated by herbimycin A (HMA). Both types of cell death were inhibited by genistein. In this study, we investigated the effects of HMA and genistein on cell cycle regulation and its correlation with the alterations of radiation-induced cell death. K562 cells in exponential growth phase were used for this study. The cells were irradiated with 10 Gy using 6 MeV Linac (200-300 cGy/min). Immediately after irradiation, cells were treated with 250 nM of HMA or 25{mu}M of genistein. The distributions of cell cycle, the expressions of cell cycle-related protein, the activities of cyclin-dependent kinase, and the yield of senescence and differentiation were analyzed. X-irradiated cells were arrested in the G2 phase of the cell cycle but unlike the p53-positive cells, they were not able to sustain the cell cycle arrest. An accumulation of cells in G2 phase of first cell-cycle post-treatment and an increase of cyclin B1 were correlated with spontaneous, premature, chromosome condensation and mitotic catastrophe. HMA induced rapid G2 checkpoint abrogation and concomitant p53-independent G1 accumulation HMA-induced cell cycle modifications correlated with the increase of cdc2 kinase activity, the decrease of the expressions of cyclins E and A and of CDK2 kinase activity, and the enhancement of radiation-induced apoptosis. Genistein maintained cells that were arrested in the G2-phase, decreased the expressions of cyclin B1 and cdc25C and cdc2 kinase activity, increased the expression of p16, and sustained senescence and megakaryocytic differentiation. The effects of HMA and genistein on the radiation-induced cell death of K562 cells were closely related to the cell

  9. Pathway-specific differences between tumor cell lines and normal and tumor tissue cells

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    Tozeren Aydin

    2006-11-01

    Full Text Available Abstract Background Cell lines are used in experimental investigation of cancer but their capacity to represent tumor cells has yet to be quantified. The aim of the study was to identify significant alterations in pathway usage in cell lines in comparison with normal and tumor tissue. Methods This study utilized a pathway-specific enrichment analysis of publicly accessible microarray data and quantified the gene expression differences between cell lines, tumor, and normal tissue cells for six different tissue types. KEGG pathways that are significantly different between cell lines and tumors, cell lines and normal tissues and tumor and normal tissue were identified through enrichment tests on gene lists obtained using Significance Analysis of Microarrays (SAM. Results Cellular pathways that were significantly upregulated in cell lines compared to tumor cells and normal cells of the same tissue type included ATP synthesis, cell communication, cell cycle, oxidative phosphorylation, purine, pyrimidine and pyruvate metabolism, and proteasome. Results on metabolic pathways suggested an increase in the velocity nucleotide metabolism and RNA production. Pathways that were downregulated in cell lines compared to tumor and normal tissue included cell communication, cell adhesion molecules (CAMs, and ECM-receptor interaction. Only a fraction of the significantly altered genes in tumor-to-normal comparison had similar expressions in cancer cell lines and tumor cells. These genes were tissue-specific and were distributed sparsely among multiple pathways. Conclusion Significantly altered genes in tumors compared to normal tissue were largely tissue specific. Among these genes downregulation was a major trend. In contrast, cell lines contained large sets of significantly upregulated genes that were common to multiple tissue types. Pathway upregulation in cell lines was most pronounced over metabolic pathways including cell nucleotide metabolism and oxidative

  10. UVB radiation induced effects on cells studied by FTIR spectroscopy

    CERN Document Server

    Di Giambattista, Lucia; Gaudenzi, S; Pozzi, D; Grandi, M; Morrone, S; Silvestri, I; Castellano, A Congiu; 10.1007/s00249-009-0446-9

    2010-01-01

    We have made a preliminary analysis of the results about the eVects on tumoral cell line (lymphoid T cell line Jurkat) induced by UVB radiation (dose of 310 mJ/cm^2) with and without a vegetable mixture. In the present study, we have used two techniques: Fourier transform infrared spectroscopy (FTIR) and flow cytometry. FTIR spectroscopy has the potential to provide the identiWcation of the vibrational modes of some of the major compounds (lipid, proteins and nucleic acids) without being invasive in the biomaterials. The second technique has allowed us to perform measurements of cytotoxicity and to assess the percentage of apoptosis. We already studied the induction of apoptotic process in the same cell line by UVB radiation; in particular, we looked for correspondences and correlations between FTIR spetroscopy and flow cytometry data finding three highly probable spectroscopic markers of apoptosis (Pozzi et al. in Radiat Res 168:698-705, 2007). In the present work, the results have shown significant changes ...

  11. Extracellular Vesicles from Ovarian Carcinoma Cells Display Specific Glycosignatures

    Directory of Open Access Journals (Sweden)

    Joana Gomes

    2015-08-01

    Full Text Available Cells release vesicles to the extracellular environment with characteristic nucleic acid, protein, lipid, and glycan composition. Here we have isolated and characterized extracellular vesicles (EVs and total cell membranes (MBs from ovarian carcinoma OVMz cells. EVs were enriched in specific markers, including Tsg101, CD63, CD9, annexin-I, and MBs contained markers of cellular membrane compartments, including calnexin, GRASP65, GS28, LAMP-1, and L1CAM. The glycoprotein galectin-3 binding protein (LGALS3BP was strongly enriched in EVs and it contained sialylated complex N-glycans. Lectin blotting with a panel of lectins showed that EVs had specific glycosignatures relative to MBs. Furthermore, the presence of glycoproteins bearing complex N-glycans with α2,3-linked sialic acid, fucose, bisecting-GlcNAc and LacdiNAc structures, and O-glycans with the T-antigen were detected. The inhibition of N-glycosylation processing from high mannose to complex glycans using kifunensine caused changes in the composition of EVs and induced a decrease of several glycoproteins. In conclusion, the results showed that glycosignatures of EVs were specific and altered glycosylation within the cell affected the composition and/or dynamics of EVs release. Furthermore, the identified glycosignatures of EVs could provide novel biomarkers for ovarian cancer.

  12. The sensitivity of human mesenchymal stem cells to ionizing radiation

    International Nuclear Information System (INIS)

    Purpose: Recent studies have shown that mesenchymal stem cells (MSCs) obtained from bone marrow transplantation patients originate from the host. This clinical observation suggests that MSCs in their niches could be resistant to irradiation. However, the biologic responses of bone marrow MSCs to irradiation have rarely been described in the literature. Methods and Materials: In this study, human bone marrow-derived, clonally expanded MSCs were used to investigate their sensitivity to irradiation in vitro, and the cellular mechanisms that may facilitate resistance to irradiation. The human lung cancer cell line A549 and the breast cancer cell line HCC1937 were used as controls for radiosensitivity; the former line has been shown to be radioresistant and the latter radiosensitive. We then examined their in vitro biologic changes and sensitivities to radiation therapy. Results: Our results suggest that MSCs are characterized as resistant to irradiation. Several cellular mechanisms were demonstrated that may facilitate resistance to irradiation: ATM protein phosphorylation, activation of cell-cycle checkpoints, double-strand break repair by homologous recombination and nonhomologous end joining (NHEJ), and the antioxidant capacity for scavenging reactive oxygen species. Conclusions: As demonstrated, MSCs possess a better antioxidant reactive oxygen species-scavenging capacity and active double-strand break repair to facilitate their radioresistance. These findings provide a better understanding of radiation-induced biologic responses in MSCs and may lead to the development of better strategies for stem cell treatment and cancer therapy

  13. Radiation-induced chromosomal instability in human mammary epithelial cells

    Science.gov (United States)

    Durante, M.; Grossi, G. F.; Yang, T. C.

    1996-01-01

    Karyotypes of human cells surviving X- and alpha-irradiation have been studied. Human mammary epithelial cells of the immortal, non-tumorigenic cell line H184B5 F5-1 M/10 were irradiated and surviving clones isolated and expanded in culture. Cytogenetic analysis was performed using dedicated software with an image analyzer. We have found that both high- and low-LET radiation induced chromosomal instability in long-term cultures, but with different characteristics. Complex chromosomal rearrangements were observed after X-rays, while chromosome loss predominated after alpha-particles. Deletions were observed in both cases. In clones derived from cells exposed to alpha-particles, some cells showed extensive chromosome breaking and double minutes. Genomic instability was correlated to delayed reproductive death and neoplastic transformation. These results indicate that chromosomal instability is a radiation-quality-dependent effect which could determine late genetic effects, and should therefore be carefully considered in the evaluation of risk for space missions.

  14. On the use of age-specific effective dose coefficients in radiation protection of the public

    International Nuclear Information System (INIS)

    Current radiation protection standards for the public include a limit on effective dose in any year for individuals in critical groups. This paper considers the question of how the annual dose limit should be applied in controlling routine exposures of populations consisting of individuals of all ages. We assume that the fundamental objective of radiation protection is limitation of lifetime risk and, therefore, that standards for controlling routine exposures of the public should provide a reasonable correspondence with lifetime risk, taking into account the age dependence of intakes and doses and the variety of radionuclides and exposure pathways of concern. Using new calculations of the per capita (population-averaged) risk of cancer mortality per unit activity inhaled or ingested in the U.S. Environmental Protection Agency's Federal Guidance Report No. 13, we show that applying a limit on annual effective dose only to adults, which was the usual practice in radiation protection of the public before the development of age-specific effective dose coefficients, provides a considerably better correspondence with lifetime risk that applying the annual dose limit to the critical group of any age. (author)

  15. On the use of age-specific effective dose coefficients in radiation protection of the public

    International Nuclear Information System (INIS)

    Current radiation protection standards for the public include a limit on effective dose in any year for individuals in critical groups. This paper considers the question of how the annual dose limit should be applied in controlling routine exposures of populations consisting of individuals of all ages. The authors assume that the fundamental objective of radiation protection is limitation of lifetime risk and, therefore, that standards for controlling routine exposures of the public should provide a reasonable correspondence with lifetime risk, taking into account the age dependence of intakes and doses and the variety of radionuclides and exposure pathways of concern. Using new calculations of the per capita (population-averaged) risk of cancer mortality per unit activity inhaled or ingested in the US Environmental Protection Agency's Federal Guidance Report No. 13, the authors show that applying a limit on annual effective dose only to adults, which was the usual practice in radiation protection of the public before the development of age-specific effective dose coefficients, provides a considerably better correspondence with lifetime risk than applying the annual dose limit to the critical group of any age

  16. Evaluation of Late Effects of Heavy-Ion Radiation on Mesenchymal Stem Cells

    Science.gov (United States)

    Gonda, S.R.; Behravesh, E.; Huff, J.L.; Johnson, F.

    2005-01-01

    The overall objective of this recently funded study is to utilize well-characterized model test systems to assess the impact of pluripotent stem cell differentiation on biological effects associated with high-energy charged particle radiation. These stem cells, specifically mesenchymal stem cells (MSCs), have the potential for differentiation into bone, cartilage, fat, tendons, and other tissue types. The characterization of the regulation mechanisms of MSC differentiation to the osteoblastic lineage by transcription factors, such as Runx2/Cbfa1 and Osterix, and osteoinductive proteins such as members of the bone morphogenic protein family are well established. More importantly, for late biological effects, MSCs have been shown to contribute to tissue restructuring and repair after tissue injury. The complex regulation of and interactions between inflammation and repair determine the eventual outcome of the responses to tissue injury, for which MSCs play a crucial role. Additionally, MSCs have been shown to respond to reactive oxygen species, a secondary effector of radiation, by differentiating. With this, we hypothesized that differentiation of MSCs can alter or exacerbate the damage initiated by radiation, which can ultimately lead to late biological effects of misrepair/fibrosis which may ultimately lead to carcinogenesis. Currently, studies are underway to examine high-energy X-ray radiation at low and high doses, approximately 20 and 200 Rad, respectively, on cytogenetic damage and gene modulation of isolated MSCs. These cells, positive for MSC surface markers, were obtained from three persons. In vitro cell samples were harvested during cellular proliferation and after both cellular recovery and differentiation. Future work will use established in vitro models of increasing complexity to examine the value of traditional 2D tissue-culture techniques, and utilize 3D in vitro tissue culture techniques that can better assess late effects associated with

  17. Acquired Tumor Cell Radiation Resistance at the Treatment Site Is Mediated Through Radiation-Orchestrated Intercellular Communication

    Energy Technology Data Exchange (ETDEWEB)

    Aravindan, Natarajan, E-mail: naravind@ouhsc.edu [Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma (United States); Aravindan, Sheeja; Pandian, Vijayabaskar; Khan, Faizan H.; Ramraj, Satish Kumar; Natt, Praveen [Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma (United States); Natarajan, Mohan [Department of Pathology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas (United States)

    2014-03-01

    Purpose: Radiation resistance induced in cancer cells that survive after radiation therapy (RT) could be associated with increased radiation protection, limiting the therapeutic benefit of radiation. Herein we investigated the sequential mechanistic molecular orchestration involved in radiation-induced radiation protection in tumor cells. Results: Radiation, both in the low-dose irradiation (LDIR) range (10, 50, or 100 cGy) or at a higher, challenge dose IR (CDIR), 4 Gy, induced dose-dependent and sustained NFκB-DNA binding activity. However, a robust and consistent increase was seen in CDIR-induced NFκB activity, decreased DNA fragmentation, apoptosis, and cytotoxicity and attenuation of CDIR-inhibited clonal expansion when the cells were primed with LDIR prior to challenge dose. Furthermore, NFκB manipulation studies with small interfering RNA (siRNA) silencing or p50/p65 overexpression unveiled the influence of LDIR-activated NFκB in regulating CDIR-induced DNA fragmentation and apoptosis. LDIR significantly increased the transactivation/translation of the radiation-responsive factors tumor necrosis factor-α (TNF-α), interleukin-1α (IL-1α), cMYC, and SOD2. Coculture experiments exhibit LDIR-influenced radiation protection and increases in cellular expression, secretion, and activation of radiation-responsive molecules in bystander cells. Individual gene-silencing approach with siRNAs coupled with coculture studies showed the influence of LDIR-modulated TNF-α, IL-1α, cMYC, and SOD2 in induced radiation protection in bystander cells. NFκB inhibition/overexpression studies coupled with coculture experiments demonstrated that TNF-α, IL-1α, cMYC, and SOD2 are selectively regulated by LDIR-induced NFκB. Conclusions: Together, these data strongly suggest that scattered LDIR-induced NFκB-dependent TNF-α, IL-1α, cMYC, and SOD2 mediate radiation protection to the subsequent challenge dose in tumor cells.

  18. Acquired Tumor Cell Radiation Resistance at the Treatment Site Is Mediated Through Radiation-Orchestrated Intercellular Communication

    International Nuclear Information System (INIS)

    Purpose: Radiation resistance induced in cancer cells that survive after radiation therapy (RT) could be associated with increased radiation protection, limiting the therapeutic benefit of radiation. Herein we investigated the sequential mechanistic molecular orchestration involved in radiation-induced radiation protection in tumor cells. Results: Radiation, both in the low-dose irradiation (LDIR) range (10, 50, or 100 cGy) or at a higher, challenge dose IR (CDIR), 4 Gy, induced dose-dependent and sustained NFκB-DNA binding activity. However, a robust and consistent increase was seen in CDIR-induced NFκB activity, decreased DNA fragmentation, apoptosis, and cytotoxicity and attenuation of CDIR-inhibited clonal expansion when the cells were primed with LDIR prior to challenge dose. Furthermore, NFκB manipulation studies with small interfering RNA (siRNA) silencing or p50/p65 overexpression unveiled the influence of LDIR-activated NFκB in regulating CDIR-induced DNA fragmentation and apoptosis. LDIR significantly increased the transactivation/translation of the radiation-responsive factors tumor necrosis factor-α (TNF-α), interleukin-1α (IL-1α), cMYC, and SOD2. Coculture experiments exhibit LDIR-influenced radiation protection and increases in cellular expression, secretion, and activation of radiation-responsive molecules in bystander cells. Individual gene-silencing approach with siRNAs coupled with coculture studies showed the influence of LDIR-modulated TNF-α, IL-1α, cMYC, and SOD2 in induced radiation protection in bystander cells. NFκB inhibition/overexpression studies coupled with coculture experiments demonstrated that TNF-α, IL-1α, cMYC, and SOD2 are selectively regulated by LDIR-induced NFκB. Conclusions: Together, these data strongly suggest that scattered LDIR-induced NFκB-dependent TNF-α, IL-1α, cMYC, and SOD2 mediate radiation protection to the subsequent challenge dose in tumor cells

  19. Redirecting T Cell Specificity Using T Cell Receptor Messenger RNA Electroporation.

    Science.gov (United States)

    Koh, Sarene; Shimasaki, Noriko; Bertoletti, Antonio

    2016-01-01

    Autologous T lymphocytes genetically modified to express T cell receptors or chimeric antigen receptors have shown great promise in the treatment of several cancers, including melanoma and leukemia. In addition to tumor-associated antigens and tumor-specific neoantigens, tumors expressing viral peptides can also be recognized by specific T cells and are attractive targets for cell therapy. Hepatocellular carcinoma cells often have hepatitis B virus DNA integration and can be targeted by hepatitis B virus-specific T cells. Here, we describe a method to engineer hepatitis B virus-specific T cell receptors in primary human T lymphocytes based on electroporation of hepatitis B virus T cell receptor messenger RNA. This method can be extended to a large scale therapeutic T cell production following current good manufacturing practice compliance and is applicable to the redirection of T lymphocytes with T cell receptors of other virus specificities such as Epstein-Barr virus, cytomegalovirus, and chimeric receptors specific for other antigens expressed on cancer cells. PMID:27236807

  20. Cell-specific synaptic plasticity induced by network oscillations.

    Science.gov (United States)

    Zarnadze, Shota; Bäuerle, Peter; Santos-Torres, Julio; Böhm, Claudia; Schmitz, Dietmar; Geiger, Jörg Rp; Dugladze, Tamar; Gloveli, Tengis

    2016-01-01

    Gamma rhythms are known to contribute to the process of memory encoding. However, little is known about the underlying mechanisms at the molecular, cellular and network levels. Using local field potential recording in awake behaving mice and concomitant field potential and whole-cell recordings in slice preparations we found that gamma rhythms lead to activity-dependent modification of hippocampal networks, including alterations in sharp wave-ripple complexes. Network plasticity, expressed as long-lasting increases in sharp wave-associated synaptic currents, exhibits enhanced excitatory synaptic strength in pyramidal cells that is induced postsynaptically and depends on metabotropic glutamate receptor-5 activation. In sharp contrast, alteration of inhibitory synaptic strength is independent of postsynaptic activation and less pronounced. Further, we found a cell type-specific, directionally biased synaptic plasticity of two major types of GABAergic cells, parvalbumin- and cholecystokinin-expressing interneurons. Thus, we propose that gamma frequency oscillations represent a network state that introduces long-lasting synaptic plasticity in a cell-specific manner. PMID:27218453

  1. Mechanisms of linear energy transfer-dependent radiation resistance in myeloid leukemia cells

    Science.gov (United States)

    Haro, Kurtis John

    Ionizing radiations (IRs) of high linear energy transfer (LET), such as alpha particles, produce fundamentally different forms of DNA damage in cells than conventional low LET radiation, such as gamma rays. Alpha particle therapies have recently emerged as important potential treatments of cancer, particularly for relatively easily-accessible malignancies of the hematopoietic system. Therefore, we created stable radioresistant myeloid leukemia HL60 cell clones derived after irradiation from either gamma rays (RG) or alpha particles (RA) in order to understand whether resistance to high LET (IR) was possible and the potential differences in radioresistance that could arise from radiations of different LET. Repeated irradiations yielded radioresistant HL60 clones and, regardless of derivation, displayed similar levels of resistance to IR of either type of radiation. The resistant phenotype in each type of radioresistant clone was driven by similar, multifactorial changes that included significant reductions in apoptosis, a decreased late G2/M checkpoint accumulation that was indicative of increased genomic instability, as well as more robust repair of specific types of DNA lesions that included DNA double-strand breaks (DSBs). The relative changes in resistance to alpha particles, however, were substantially lower than the increase in resistance to gamma rays. The data suggest that these processes were interdependent, as inhibition of homology directed repair in the resistant clones sensitized them to gamma IR to a larger extent than naive HL60 cells. Finally, we identified the downregulation of iron regulatory protein 1 (IRP1) in gamma-resistant cells but not in alpha-resistant cells. Short-hairpin RNA-mediated reductions in expression of IRP1 in radiation-naive HL60 cells led to significant radioresistance to gamma rays, but not alpha particles. The IRP1-mediated radioresistance was associated with changes in iron-mediated oxidative stress that led to significant

  2. Neoplastic human embryonic stem cells as a model of radiation resistance of human cancer stem cells.

    Science.gov (United States)

    Dingwall, Steve; Lee, Jung Bok; Guezguez, Borhane; Fiebig, Aline; McNicol, Jamie; Boreham, Douglas; Collins, Tony J; Bhatia, Mick

    2015-09-01

    Studies have implicated that a small sub-population of cells within a tumour, termed cancer stem cells (CSCs), have an enhanced capacity for tumour formation in multiple cancers and may be responsible for recurrence of the disease after treatment, including radiation. Although comparisons have been made between CSCs and bulk-tumour, the more important comparison with respect to therapy is between tumour-sustaining CSC versus normal stem cells that maintain the healthy tissue. However, the absence of normal known counterparts for many CSCs has made it difficult to compare the radiation responses of CSCs with the normal stem cells required for post-radiotherapy tissue regeneration and the maintenance of tissue homeostasis. Here we demonstrate that transformed human embryonic stem cells (t-hESCs), showing features of neoplastic progression produce tumours resistant to radiation relative to their normal counterpart upon injection into immune compromised mice. We reveal that t-hESCs have a reduced capacity for radiation induced cell death via apoptosis and exhibit altered cell cycle arrest relative to hESCs in vitro. t-hESCs have an increased expression of BclXL in comparison to their normal counterparts and re-sensitization of t-hESCs to radiation upon addition of BH3-only mimetic ABT737, suggesting that overexpression of BclXL underpins t-hESC radiation insensitivity. Using this novel discovery platform to investigate radiation resistance in human CSCs, our study indicates that chemotherapy targeting Bcl2-family members may prove to be an adjuvant to radiotherapy capable of targeting CSCs.

  3. Development of a site specific environmental radiation assessment model for Youngkwang NPPs

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Yang Geun; Song, Myung Jae; Shon, Soon Hwan; Shin, Sang Woon; Lee, Gap Bock; Yang, Kyung Hwa [Korea Electric Power Research Institute, Taejon (Korea, Republic of); Kim, Seong Pyung; Kim, Jeong Kyu; Shin, Dae Yoon; Kim, Hyun Ku; Lee, Kyung Jin [Chosun University, Kwangju (Korea, Republic of)

    1996-12-31

    During the normal operation of nuclear power plants, a very small amount of radionuclide materials is released to the environment. The radionuclide releases to the environment may give rise to some additional radiation dose through a number of pathways. With a few exception, radionuclide transports are highly dependent on the environmental conditions such as topological features, atmospheric and oceanic conditions and socio-environmental characteristics, etc. The dose calculation in Korea are presently being performed using the models in US NRC Reg. Guide. However, these models which were originally released by the US NRC in 1977 are inadequate to deal with environmental movement of radionuclides in consideration of complex terrain, tidal condition of the Yellow Sea, and Youngkwang site specific conditions. KEPRI has developed the models to consider the site specific characteristics around Youngkwang NPPs, to give the realistic dose assessment, and to improve assurance and reliability in public dose calculation. (author). 41 figs., 70 refs.

  4. Potential cell-specific functions of CXCR4 in atherosclerosis.

    Science.gov (United States)

    Weber, Christian; Döring, Yvonne; Noels, Heidi

    2016-05-10

    The chemokine CXCL12 and its receptor CXCR4 form an important axis contributing to cellular functions in homeostasis and disease. In addition, the atypical CXCL12 receptor CXCR7 may shape the availability and function of CXCL12. Further to their role through progenitor cell mobilization, CXCL12 and CXCR4 may affect native atherogenesis by modifying atherosclerosis-relevant cellular functions. This short review intends to provide a concise summary of current knowledge with regards to cell-specific functions of CXCL12 and its receptors CXCR4 and CXCR7 with potential implications for the initiation and progression of atherosclerosis. PMID:25586789

  5. Specific Control of Immunity by Regulatory CD8 T Cells

    Institute of Scientific and Technical Information of China (English)

    XiaoleiTang; TrevorRFSmith

    2005-01-01

    T lymphocytes with dedicated suppressor function (Treg) play a crucial role in the homeostatic control of immunity in the periphery. Several Treg phenotypes have now been identified in the CD4 and CD8 T cell populations, suggesting their down-regulatory function in both human and animal models of autoimmunity, transplantation and tumor immunity. Here we will focus on the CD8 Treg population and their ability to specifically inhibit a pathogenic autoimmune response. This review will detail the current advances in the knowledge of CD8 Treg in the context of antigen specificity, phenotype, MHC restriction, mechanism of action, and priming. Cellular & Molecular Immunology. 2005;2(1):11-19.

  6. Radiation response of spermatogonial stem cells in the mouse

    International Nuclear Information System (INIS)

    Spermatogonial stem cells are able to repopulate the testis by forming clones that elongate along the walls of the seminiferous tubules depleted of spermatogenetic cells as a result of an irradiation. The surviving number of stem cells after irradiation was estimated by determining the fraction of repopulated tubules in cross-sections of the testis 11 weeks after irradiation. This fraction, called the 'repopulation index', is assumed to be directly proportional to the number of surviving stem cells. The response of spermatogonial stem cells in the CBA mouse to 1-MeV fission neutrons was investigated. Radioresistant, colony forming stem cells in the mouse testis move into a much more radiosensitive phase of their cell cycle shortly after irradiation. This is demonstrated in publication II in experiments in which total doses of 300 rad of neutrons and 1200 rad of X-rays were split into two equal fractions. The radiation response of spermatogonial stem cells in the mouse which survived various doses of fission neutrons 24 hours before was studied in publication III. Twenty four hours after a dose of 150 rad of fission neutrons all first-dose survivors have moved from a radioresistant (D0 89+-4 rad in this study) towards a radiosensitive phase of their cell cycle. Spermatogonial stem cells which survive a neutron dose of 150 rad all belong to a radioresistant stem cell population in the seminiferous epithelium. The data in publication IV show that during the first 26 days after a dose of 150 rad of neutrons the stem cell population first increases and then slowly decreases its radiosensitivity, to stay fixed at a relatively high level. (Auth.)

  7. Site-Specific Genome Engineering in Human Pluripotent Stem Cells

    Science.gov (United States)

    Merkert, Sylvia; Martin, Ulrich

    2016-01-01

    The possibility to generate patient-specific induced pluripotent stem cells (iPSCs) offers an unprecedented potential of applications in clinical therapy and medical research. Human iPSCs and their differentiated derivatives are tools for diseases modelling, drug discovery, safety pharmacology, and toxicology. Moreover, they allow for the engineering of bioartificial tissue and are promising candidates for cellular therapies. For many of these applications, the ability to genetically modify pluripotent stem cells (PSCs) is indispensable, but efficient site-specific and safe technologies for genetic engineering of PSCs were developed only recently. By now, customized engineered nucleases provide excellent tools for targeted genome editing, opening new perspectives for biomedical research and cellular therapies. PMID:27347935

  8. Cell reprogramming for the creation of patient-specific pluripotent stem cells by defined factors

    Institute of Scientific and Technical Information of China (English)

    Huiqun YIN; Heng WANG; Hongguo CAO; Yunhai ZHANG; Yong TAO; Xiaorong ZHANG

    2009-01-01

    Pluripotent stem cells (PSCs), characterized by being able to differentiate into various types of cells, are generally regarded as the most promising sources for cell replacement therapies. However, as typical PSCs, embryonic stem cells (ESCs) are still far away from human clinics so far due to ethical issues and immune rejection response. One way to avoid such problems is to use stem cells derived from autologous somatic cells. Up to date, PSCs could be obtained by reprogramming somatic cells to pluripotent state with approaches including somatic cell nuclear transfer (SCNT), fusion with stem cells, coculture with cells' extracts, and induction with defined factors. Among these, through reprogramming somatic cells directly by retroviral transduction of transcription factors, induced pluripotent stem (iPS) cells have been successfully generated in both mouse and human recently. These iPS cells shared similar morphology and growth properties to ESCs, could express ESCs marker genes, and could produce adult or germline-competent chimaeras and differentiate into a variety of cell types, including germ cells. Moreover, with iPS technique, patient specific PSCs could be derived more easily from handful somatic cells in human without immune rejection responses innately connected to ESCs. Consequently, generation of iPS cells would be of great help to further understand disease mechanisms, drug screening, and cell transplantation therapies as well.In summary,the recent progress in the study of cell reprogramming for the creation of patientspecific pluripotent stem cells, some existing problems, and research perspectives were suggested.

  9. Generation of Transplantable Beta Cells for Patient-Specific Cell Therapy

    Directory of Open Access Journals (Sweden)

    Xiaojie Wang

    2012-01-01

    Full Text Available Islet cell transplantation offers a potential cure for type 1 diabetes, but it is challenged by insufficient donor tissue and side effects of current immunosuppressive drugs. Therefore, alternative sources of insulin-producing cells and isletfriendly immunosuppression are required to increase the efficiency and safety of this procedure. Beta cells can be transdifferentiated from precursors or another heterologous (non-beta-cell source. Recent advances in beta cell regeneration from somatic cells such as fibroblasts could circumvent the usage of immunosuppressive drugs. Therefore, generation of patient-specific beta cells provides the potential of an evolutionary treatment for patients with diabetes.

  10. Low- and high-LET radiation drives clonal expansion of lung progenitor cells in vivo

    OpenAIRE

    Farin, Alicia M.; Manzo, Nicholas D.; Kirsch, David G.; Stripp, Barry R.

    2015-01-01

    Abundant populations of epithelial progenitor cells maintain the epithelium along the proximal-to-distal axis of the airway. Exposure of lung tissue to ionizing radiation leads to tissue remodeling and potential cancer initiation or progression. However, little is known about the effects of ionizing radiation on airway epithelial progenitor cells. We hypothesized that ionizing radiation exposure will alter the behavior of airway epithelial progenitor cells in a radiation dose- and quality-dep...

  11. Cell-specific regulation of apoptosis by designed enediynes.

    OpenAIRE

    Nicolaou, K. C.; Stabila, P; Esmaeli-Azad, B; Wrasidlo, W; Hiatt, A

    1993-01-01

    The naturally occurring enediyne antibiotics are a unique class of antitumor drugs that combine reactive enediynes with additional structural features conferring affinity for DNA. Dynemicin A, in which an enediyne core is attached to an anthraquinone group capable of DNA intercalation, readily cleaves double-stranded DNA. This activity is thought to be the basis of its potent antitumor cytotoxicity. To investigate cell-specific mechanisms of cytotoxicity in the absence of DNA affinity, we hav...

  12. RADIATION-INDUCED APOPTOSIS OF TWO NASOPHARANGEAL CARCINOMA CELL LINES

    Institute of Scientific and Technical Information of China (English)

    WANG Feng-wei; LIANG Ke; YIN Wei-bo; SHEN Yu; SHENG Xiu-gui

    1999-01-01

    Objective: To study apoptosis induced by radiation in two nasopharyngeal carcinoma (NPC) cell lines, CNE and CNE-2. Methods: Hoechst 33342 staining, immunohistochemical staining, RT-PCR, DNA dot blotting and Southern blotting were used to identify apoptosis.Results: A single dose of X-irradiation resulted in apoptosis, the apoptotic index (AI) was time- and dosedependent. Different apoptotic responses existed in the two cell lines. Immunohistochemical staining showed that bcl-2 protein was strongly positive in CNE but negative in CNE-2. However, RT-PCR revealed p53mRNA in CNE-2 but not in CNE. P53 and bcl-2 genes were both present in the two cell lines as shown by DNA blotting, but the 2.8 kb fragment of the p53 gene was much lower than the 5.6 kb fragment on CNE which was clearly shown in Southern hybridization, suggestive of partial deletion of p53 gene in CNE. Conclusion:Apoptotic response to radiation is different in two NPC cell lines. CNE is more radioresistant than CNE-2.Overexpression of bcl-2 protein and partial deletion of p53 gene may explain their difference in radiosensitivity.

  13. Specific insulin binding in bovine chromaffin cells; demonstration of preferential binding to adrenalin-storing cells

    Energy Technology Data Exchange (ETDEWEB)

    Serck-Hanssen, G.; Soevik, O.

    1987-12-28

    Insulin binding was studied in subpopulations of bovine chromaffin cells enriched in adrenalin-producing cells (A-cells) or noradrenalin-producing cells (NA-cells). Binding of /sup 125/I-insulin was carried out at 15/sup 0/C for 3 hrs in the absence or presence of excess unlabeled hormone. Four fractions of cells were obtained by centrifugation on a stepwise bovine serum albumin gradient. The four fractions were all shown to bind insulin in a specific manner and the highest binding was measured in the cell layers of higher densities, containing mainly A-cells. The difference in binding of insulin to the four subpopulations of chromaffin cells seemed to be related to differences in numbers of receptors as opposed to receptor affinities. The authors conclude that bovine chromaffin cells possess high affinity binding sites for insulin and that these binding sites are mainly confined to A-cells. 24 references, 2 figures, 1 table.

  14. [Salivary gland stem cells : Can they restore radiation-induced salivary gland dysfunction?].

    Science.gov (United States)

    Rotter, N; Schwarz, S; Jakob, M; Brandau, S; Wollenberg, B; Lang, S

    2010-06-01

    Adult stem cells are actively investigated in the fields of regenerative medicine and tissue engineering, as they exhibit specific characteristics that make them promising candidates for cellular therapies. Depending on their tissue of origin these characteristics include long-term proliferation and the capacity to differentiate into various cell types. To date adult stem cells have been isolated from a multitude of tissues. Non-embryogenic adult tissues contain only small numbers of such stem cells and the derivation of such tissues can cause comorbidities. Therefore, there is ongoing interest in the identification and characterisation of novel cell sources for stem cell isolation and characterisation.Recently, salivary gland tissue has also been explored as a possible source of stem cells, first in animals and later in humans. Such salivary gland-derived stem cells might be useful in the treatment of radiation-induced salivary gland hypofunction, and possibly also in other diseases with loss of acinar cells, such as sequelae of radio iodine treatment or Sjögren's disease.In this paper we review the current status of salivary gland stem cell biology and application and discuss the possible role of stem cells in the development of novel therapies for salivary gland dysfunctions such as postradiogenic xerostomia.

  15. ABCG2 regulates self-renewal and stem cell marker expression but not tumorigenicity or radiation resistance of glioma cells

    Science.gov (United States)

    Wee, Boyoung; Pietras, Alexander; Ozawa, Tatsuya; Bazzoli, Elena; Podlaha, Ondrej; Antczak, Christophe; Westermark, Bengt; Nelander, Sven; Uhrbom, Lene; Forsberg-Nilsson, Karin; Djaballah, Hakim; Michor, Franziska; Holland, Eric C.

    2016-01-01

    Glioma cells with stem cell traits are thought to be responsible for tumor maintenance and therapeutic failure. Such cells can be enriched based on their inherent drug efflux capability mediated by the ABC transporter ABCG2 using the side population assay, and their characteristics include increased self-renewal, high stem cell marker expression and high tumorigenic capacity in vivo. Here, we show that ABCG2 can actively drive expression of stem cell markers and self-renewal in glioma cells. Stem cell markers and self-renewal was enriched in cells with high ABCG2 activity, and could be specifically inhibited by pharmacological and genetic ABCG2 inhibition. Importantly, despite regulating these key characteristics of stem-like tumor cells, ABCG2 activity did not affect radiation resistance or tumorigenicity in vivo. ABCG2 effects were Notch-independent and mediated by diverse mechanisms including the transcription factor Mef. Our data demonstrate that characteristics of tumor stem cells are separable, and highlight ABCG2 as a potential driver of glioma stemness. PMID:27456282

  16. Enhanced radiation response in radioresistant MCF-7 cells by targeting peroxiredoxin II

    Directory of Open Access Journals (Sweden)

    Diaz AJG

    2013-10-01

    Full Text Available Anthony Joseph Gomez Diaz,1 Daniel Tamae,2 Yun Yen,3 JianJian Li,4 Tieli Wang1 1Department of Chemistry and Biochemistry, California State University at Dominguez Hills, Carson, CA, 2Center of Excellence in Environmental Toxicology, Department of Pharmacology, University of Pennsylvania, Philadelphia, PA, 3Department of Clinical and Molecular Pharmacology, Beckman Research Institute of City of Hope National Medical Center, Duarte, CA, 4Department of Radiation Oncology, University of California Davis, Sacramento, CA, USA Abstract: In our previous study, we identified that a protein target, peroxiredoxin II (PrxII, is overexpressed in radioresistant MCF+FIR3 breast-cancer cells and found that its expression and function is associated with breast-cancer radiation sensitivity or resistance. Small interference RNA (siRNA targeting PrxII gene expression was able to sensitize MCF+FIR3 radioresistant breast-cancer cells to ionizing radiation. The major focus of this work was to investigate how the radiation response of MCF+FIR3 radioresistant cells was affected by the siRNA that inhibits PrxII gene expression. Our results, presented here, show that silencing PrxII gene expression increased cellular toxicity by altering cellular thiol status, inhibiting Ca2+ efflux from the cells, and perturbing the intracellular Ca2+ homeostasis. By combining radiotherapy and siRNA technology, we hope to develop new therapeutic strategies that may have potential to enhance the efficacy of chemotherapeutic agents due to this technology's property of targeting to specific cancer-related genes. Keywords: siRNA, PrxII, radiation resistance, Ca2+, MCF+FIR3

  17. Alterations induced in Escherichia Coli cells by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kappke, J.; Schelin, H.R.; Paschuk, S.A.; Denyak, V.; Silva, E.R. da [Federal University of Technology of Parana (CPGEI/UTFPR), Curitiba, PR (Brazil)]. E-mails: jaquekap@yahoo.com.br; schelin@cpgei.cefetpr.br; sergei@utfpr.edu.br; Jesus, E.F.O. de; Lopes, R.T. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Lab. de Instrumentacao Nuclear]. E-mails: ricardo@lin.ufrj.br; edgar@lin.ufrj.br; Carlin, N.; Toledo, E.S. [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Fisica]. E-mail: nelson.carlin@dfn.if.usp.br

    2007-07-01

    Modifications occurred in Escherichia coli cells exposed to gamma radiation ({sup 60}Co source) were investigated. The irradiations were done at the LIN-COPPE laboratory of the UFRJ and the analysis at the Biology Department of the UTFPR. The E. coli cells were irradiated with 30, 60, 90, 120, 150, 180, 210, 240, 300, 480, 600 e 750 Gy doses. The samples were analyzed with Gram-stain, biochemical tests in EPM, MIO and Lysine Broth, Simmons Cytrate Medium and Rhamnose Broth, antibiogram and isolation of auxotrophic mutants. It was observed that for the received doses the E. coli did not show morphological alterations in the tests. Some E. Coli cells showed to be able to deaminade the L-tryptophan or they changed their sensibility for amoxillin and cephaloonine after the irradiation. The existence of aauxotrophic mutants after irradiation was also verified. (author)

  18. Radiation-induced DNA double-strand break frequencies in human squamous cell carcinoma cell lines of different radiation sensitivities

    International Nuclear Information System (INIS)

    DNA neutral (pH 9-6) filter elution was used to measure radiation-induced DNA double-strand break (dsb) frequencies in eight human squamous cell carcinoma cell lines with radiosensitivities (D0) ranging from 1.07 to 2.66 Gy and D-bar values ranging from 1.46 to 4.08 Gy. Elution profiles of unirradiated samples from more radiosensitive cell lines were all steeper in slope than profiles from resistant cells. The shapes of the dsb induction curves were curvilinear and there was some variability from cell line to cell line in the dose-response for the induction of DNA dsb after exposures to 5-100 Gy 60Co γ-rays. There was no relation between shapes of survival curves and shapes of the dose-responses for the induction of DNA dsb. At low doses (5-25 Gy), three out of four of the more sensitive cell lines (D-bar3.0 Gy). Although the low-dose (5-25 Gy) elution results were variable, they suggest that DNA neutral elution will detect differences between sensitive and resistant tumour cells in initial DNA dsb frequencies. (author)

  19. Interactions between endothelial cells and T cells modulate responses to mixed neutron/gamma radiation.

    Science.gov (United States)

    Cary, Lynnette H; Noutai, Daniel; Salber, Rudolph E; Williams, Margaret S; Ngudiankama, Barbara F; Whitnall, Mark H

    2014-06-01

    Detonation of an improvised nuclear device near a population center would cause significant casualties from the acute radiation syndrome (ARS) due to exposure to mixed neutron/gamma fields (MF). The pathophysiology of ARS involves inflammation, microvascular damage and alterations in immune function. Interactions between endothelial cells (EC) and hematopoietic cells are important not only for regulating immune cell traffic and function, but also for providing the microenvironment that controls survival, differentiation and migration of hematopoietic stem and progenitor cells in blood-forming tissues. Endothelial cells/leukocyte interactions also influence tumor progression and the results of anticancer therapies. In this study, we hypothesized that irradiation of endothelial cells would modulate their effects on hematopoietic cells and vice versa. Human umbilical vein endothelial cells (HUVEC) and immortalized T lymphocytes (Jurkat cells) were cultured individually and in co-culture after exposure to mixed fields. Effects of nonirradiated cells were compared to effects of irradiated cells and alterations in signaling pathways were determined. Mitogen-activated protein kinases (MAPKs) p38 and p44/42 (ERK1/2) in HUVEC exhibited higher levels of phosphorylated protein after exposure to mixed field radiation. IL-6, IL-8, G-CSF, platelet derived growth factor (PDGF) and angiopoietin 2 (ANG2) protein expression were upregulated in HUVEC by exposure to mixed field radiation. PCR arrays using HUVEC mRNA revealed alterations in gene expression after exposure to mixed fields and/or co-culture with Jurkat cells. The presence of HUVEC also influenced the function of Jurkat cells. Nonirradiated Jurkat cells showed an increase in proliferation when co-cultured with nonirradiated HUVEC, and a decrease in proliferation when co-cultured with irradiated HUVEC. Additionally, nonirradiated Jurkat cells incubated in media from irradiated HUVEC exhibited upregulation of activated

  20. Photoreactivation of ICR 2A frog cells after exposure to monochromatic ultraviolet radiation in the 252-313 nm range

    International Nuclear Information System (INIS)

    Exposure of ICR 2A frog cells to photoreactivating light after treatment with monochromatic ultraviolet (UV) radiation in the 252-313nm range resulted in an increase in survival with similar photoreactivable sectors for each of the wavelengths tested. As photoreactivating enzyme is specific for the repair of pyrimidine dimers in DNA, these findings support the hypothesis that these are critical lesions responsible for killing of cells exposed to UV radiation in this wavelength range. The action spectra for cell killing and production of UV-endonuclease sensitive sites were similar to the DNA absorption spectrum though not identical. Because the number of endonuclease sensitive sites is a reflection of the yield of pyrimidine dimers, these data also suggest that the induction of dimers in DNA by UV radiation in the 252-313 nm range is the principle event leading to cell death. (author)

  1. Radiation induced formation of giant cells (Saccharomyces uvarum). Pt. 1

    International Nuclear Information System (INIS)

    X-irradiated yeast cells (Saccharomyces uvarum) grown in liquid media stop mitosis and form giant cells. Chitin ring formation, being a prerequisite for cell separation, was studied by fluorescence microscopy using Calcofluor White, a chitin specific dye. Experiments with inhibitors of DNA synthesis (hydroxyurea) and chitin synthesis (polyoxin D) demonstrate chitin ring formation to be dependent on DNA synthesis, whereas bud formation is independent of DNA synthesis and chitin ring formation respectively. Basing on these results the formation of X-ray induced giant cells implies one DNA replication which in turn induces the formation of only one chitin ring between mother cell and giant bud. Obviously no septum can be formed. Thus cell separation does not occur, but the bud already formed, produces another bud demonstrating that bud formation itself is independent of DNA synthesis. (orig.)

  2. Effects of X-radiation on lung cancer cells: the interplay between oxidative stress and P53 levels.

    Science.gov (United States)

    Mendes, Fernando; Sales, Tiago; Domingues, Cátia; Schugk, Susann; Abrantes, Ana Margarida; Gonçalves, Ana Cristina; Teixo, Ricardo; Silva, Rita; Casalta-Lopes, João; Rocha, Clara; Laranjo, Mafalda; Simões, Paulo César; Ribeiro, Ana Bela Sarmento; Botelho, Maria Filomena; Rosa, Manuel Santos

    2015-12-01

    Lung cancer (LC) ranks as the most prevalent and deadliest cause of cancer death worldwide. Treatment options include surgery, chemotherapy and/or radiotherapy, depending on LC staging, without specific highlight. The aim was to evaluate the effects of X-radiation in three LC cell lines. H69, A549 and H1299 cell lines were cultured and irradiated with 0.5-60 Gy of X-radiation. Cell survival was evaluated by clonogenic assay. Cell death and the role of reactive oxygen species, mitochondrial membrane potential, BAX, BCL-2 and cell cycle were analyzed by flow cytometry. Total and phosphorylated P53 were assessed by western blotting. Ionizing radiation decreases cell proliferation and viability in a dose-, time- and cell line-dependent manner, inducing cell death preferentially by apoptosis with cell cycle arrest. These results may be related to differences in P53 expression and oxidative stress response. The results obtained indicate that sensibility and/or resistance to radiation may be dependent on molecular LC characteristics which could influence response to radiotherapy and treatment success. PMID:26582337

  3. Modulation of human cell responses to space radiation by gap-junction communication

    Science.gov (United States)

    Autsavapromporn, Narongchai; de Toledo, Sonia M.; Buonanno, Manuela; Yang, Zhi; Harris, Andrew; Jay-Gerin, Jean-Paul; Azzam, Edouard

    Understanding the biological effects of space radiation and their underlying mechanism is critical to estimating the health risk associated with human exploration of space. A coordinated interaction of multiple cellular processes is likely involved in the sensing and processing of stressful effects induced by different types of space radiation. Here, we focused on the role of gap-junction intercellular communication (GJIC) in responses of human cells exposed to 1 GeV/n protons or 56 Fe-ions. We compared the results with data obtained in human cells exposed, in parallel, to γ-rays or α-particles. As expected, a higher level of cell killing and DNA damage, per unit dose, was induced in confluent, density-inhibited cells (98% in G0 /G1 ) exposed to α-particles or energetic 56 Fe-ions than γ-rays or protons. Strikingly, greatly attenuated effects occurred when sub-confluent cultures, synchronized in G0 /G1 ,were exposed to 56 Fe-ions. These data suggest that direct intercellular communication is involved in the effects of high linear energy transfer (LET) 56 Fe-ions. To examine the role of gap-junctions in propagating stressful effect, confluent cultures were exposed to 56 Fe-ions or α-particles and incubated for various time periods at 37° C in the presence or absence of the gap-junction inhibitor α-glycyrrhetinic acid (AGA). No repair of potentially lethal radiation damage occurred in cells incubated in the absence of AGA. In contrast, inhibition of functional GJIC significantly enhanced clonogenic survival of irradiated cells. To test the role of junctional channel permeability in the observed effects, we used human adenocarcinoma (HeLa) cells in which specific connexins (Cx) can be expressed in the absence of endogenous connexins. Whereas HeLa cells with selective inducible expression of Cx26 gap-junctions promoted radiation toxic effects, expression of Cx32 junctional channels in HeLa cells promoted pro-survival effects. Experiments are in progress to

  4. Cell surface appearance of unexpected host MHC determinants on thymocytes from radiation bone marrow chimeras

    International Nuclear Information System (INIS)

    The phenotypic appearance of cell surface antigens on murine thymocytes from long-term radiation bone marrow chimeras was analyzed using indirect immunofluorescence and flow microfluorometry. Cells maturing in the thymi of these mice were typed for MHC (Kk, I-Ak, H-2b, Kb, and Ib) and non-MHC (Lty 1, Ly 9, and TL) determinants. All cells were of donor origin as determined by non-MHC (Ly) phenotype in P1 leads to P2, P1 x P2 leads to P1, and P1 leads to P2 radiation chimeras. In contrast, the MHC phenotypes of these thymocytes were markedly affected by the host environment. Specifically, H-2 and I-A determinants of both parental phenotypes were detected on thymocytes from P1 leads to P1 x P2 chimeras; I-A determinants of host phenotype were present, whereas I-A determinants of donor phenotype were reduced on thymocytes from P1 x P2 leads to P1 chimeras; and thymocytes from P1 leads to P2 chimeras possessed H-2 and I-A determinants of host phenotype but showed reduction of donor I-A phenotype determinants. The appearance of host cell surface H-2 and I-A determinants on thymocytes from chimeras closely parallels the functional recognition of MHC determinants by T cells from chimeric mice and thus may be significantly related to the development of the self-recognition repertoire by maturing T cells

  5. Radiofrequency radiation-induced calcium ion efflux enhancement from human and other neuroblastoma cells in culture.

    Science.gov (United States)

    Dutta, S K; Ghosh, B; Blackman, C F

    1989-01-01

    To test the generality of radiofrequency radiation-induced changes in 45Ca2+ efflux from avian and feline brain tissues, human neuroblastoma cells were exposed to electromagnetic radiation at 147 MHz, amplitude-modulated (AM) at 16 Hz, at specific absorption rates (SAR) of 0.1, 0.05, 0.01, 0.005, 0.001, and 0.0005 W/kg. Significant 45Ca2+ efflux was obtained at SAR values of 0.05 and 0.005 W/kg. Enhanced efflux at 0.05 W/kg peaked at the 13-16 Hz and at the 57.5-60 Hz modulation ranges. A Chinese hamster-mouse hybrid neuroblastoma was also shown to exhibit enhanced radiation-induced 45Ca2+ efflux at an SAR of 0.05 W/kg, using 147 MHz, AM at 16 Hz. These results confirm that amplitude-modulated radiofrequency radiation can induce responses in cells of nervous tissue origin from widely different animal species, including humans. The results are also consistent with the reports of similar findings in avian and feline brain tissues and indicate the general nature of the phenomenon. PMID:2540756

  6. Taxon-specific responses of Southern Ocean diatoms to Fe enrichment revealed by synchrotron radiation FTIR microspectroscopy

    Directory of Open Access Journals (Sweden)

    O. Sackett

    2014-05-01

    Full Text Available Photosynthesis by marine diatoms contributes substantially to global biogeochemical cycling and ecosystem productivity. It is widely accepted that diatoms are extremely sensitive to changes in Fe availability, with numerous in situ experiments demonstrating rapid growth and increased export of elements (e.g. C, Si and Fe from surface waters as a result of Fe addition. Less is known about the effects of Fe enrichment on the phenotypes of diatoms, such as associated changes in nutritional value, furthermore data on taxon-specific responses is almost non-existent. Enhanced supply of nutrient-rich waters along the coast of the subantarctic Kerguelen Island provide a valuable opportunity to examine the responses of phytoplankton to natural Fe enrichment. Here we demonstrate the use of synchrotron radiation Fourier Transform Infrared (SR-FTIR microspectroscopy to analyse changes in the macromolecular composition of diatoms collected along the coast and plateau of Kerguelen Island, Southern Ocean. SR-FTIR microspectroscopy enabled the analysis of individual diatom cells from mixed communities of field-collected samples, thereby providing insight into in situ taxon-specific responses in relation to changes in Fe availability. Phenotypic responses were taxon-specific in terms of intraspecific variability and changes in proteins, amino acids, phosphorylated molecules, silicate and carbohydrates. In contrast to some previous studies, silicate levels increased under Fe enrichment, in conjunction with increases in carbohydrate stores. The highly abundant taxon Fragilariopsis kerguelensis displayed a higher level of phenotypic plasticity than Pseudo-nitzschia spp., while analysis of the data pooled across all measured taxa showed different patterns in macromolecular composition compared to those for individual taxon. This study demonstrates that taxon-specific responses to Fe enrichment may not always be accurately reflected by bulk community measurements

  7. Liver-specific gene expression in mesenchymal stem cells is induced by liver cells

    Institute of Scientific and Technical Information of China (English)

    Claudia Lange; Philipp Bassler; Michael V. Lioznov; Helge Bruns; Dietrich Kluth; Axel R. Zander; Henning C. Fiegel

    2005-01-01

    AIM: The origin of putative liver cells from distinct bone marrow stem cells, e.g. hematopoietic stem cells or multipotent adult progenitor cells was found in recent in vitro studies. Cell culture experiments revealed a key role of growth factors for the induction of liver-specific genes in stem cell cultures. We investigated the potential of rat mesenchymal stem cells (MSC) from bone marrow to differentiate into hepatocytic cells in vitro. Furthermore,we assessed the influence of cocultured liver cells on induction of liver-specific gene expression.METHODS: Mesenchymal stem cells were marked with green fluorescent protein (GFP) by retroviral gene transduction. Clonal marked MSC were either cultured under liver stimulating conditions using fibronectin-coated culture dishes and medium supplemented with SCF, HGF,EGF, and FGF-4 alone, or in presence of freshly isolated rat liver cells. Cells in cocultures were harvested and GFP+ or GFP- cells were separated using fluorescence activated cell sorting. RT-PCR analysis for the stem cell marker Thy1 and the hepatocytic markers CK-18, albumin, CK-19,and AFP was performed in the different cell populations.RESULTS: Under the specified culture conditions, rat MSC cocultured with liver cells expressed albumin-, CK-18,CK-19, and AFP-RNA over 3 weeks, whereas MSC cultured alone did not show liver specific gene expression.CONCLUSION: The results indicate that (1) rat MSC from bone marrow can differentiate towards hepatocytic lineage in vitro, and (2) that the microenvironment plays a decisive role for the induction of hepatic differentiation of rMSC.

  8. Effect of radiation dose-rate on hematopoietic cell engraftment in adult zebrafish.

    Directory of Open Access Journals (Sweden)

    Tiffany J Glass

    Full Text Available Although exceptionally high radiation dose-rates are currently attaining clinical feasibility, there have been relatively few studies reporting the biological consequences of these dose-rates in hematopoietic cell transplant (HCT. In zebrafish models of HCT, preconditioning before transplant is typically achieved through radiation alone. We report the comparison of outcomes in adult zebrafish irradiated with 20 Gy at either 25 or 800 cGy/min in the context of experimental HCT. In non-transplanted irradiated fish we observed no substantial differences between dose-rate groups as assessed by fish mortality, cell death in the kidney, endogenous hematopoietic reconstitution, or gene expression levels of p53 and ddb2 (damage-specific DNA binding protein 2 in the kidney. However, following HCT, recipients conditioned with the higher dose rate showed significantly improved donor-derived engraftment at 9 days post transplant (p ≤ 0.0001, and improved engraftment persisted at 31 days post transplant. Analysis for sdf-1a expression, as well as transplant of hematopoietic cells from cxcr4b -/- zebrafish, (odysseus, cumulatively suggest that the sdf-1a/cxcr4b axis is not required of donor-derived cells for the observed dose-rate effect on engraftment. Overall, the adult zebrafish model of HCT indicates that exceptionally high radiation dose-rates can impact HCT outcome, and offers a new system for radiobiological and mechanistic interrogation of this phenomenon. Key words: Radiation dose rate, Total Marrow Irradiation (TMI, Total body irradiation (TBI, SDF-1, Zebrafish, hematopoietic cell transplant.

  9. Equivalent circuit analysis of radiative coupling in monolithic tandem solar cells

    International Nuclear Information System (INIS)

    As solar cell efficiency improves towards the Shockley-Queisser limit, so does the radiative efficiency of the cell. For tandem stacks of cells where energy conversion efficiency now exceeds 46%, radiative coupling between the cells is becoming increasingly important to consider in cell design, measurement, and performance prediction. We show how an equivalent circuit model can capture the complex radiative interactions between cells in such tandem stacks, allowing more insight into the impact on cell performance. The circuit's use is demonstrated by deriving results relevant to the critical step of eliminating coupling effects from measured cell spectral responses

  10. Response of hematopoietic stem cells to ionizing radiation; Reponse des cellules souches hematopoitiques aux radiations ionisantes

    Energy Technology Data Exchange (ETDEWEB)

    Simonnet, A

    2008-12-15

    Hematopoietic stem cells (HSCs) maintain blood and immune system throughout life and restore them after hematological injuries. Exposure of an organism to ionizing radiation (IR) causes rapid and acute myelosuppression and challenges the replenishment capacity of HSCs. Yet, the precise damages that are generated remain largely unexplored. To better understand these effects, phenotypic and functional changes in the stem/progenitor compartments of sublethally irradiated mice were monitored over a ten week period after radiation exposure. We report that shortly after sublethal IR-exposure, HSCs, defined by their repopulating ability, still segregate in the Hoechst dye excluding side population (SP); yet, their Sca-1 (S) and c-Kit (K) expression levels are increased and severely reduced, respectively, with a concurrent increase in the proportion of SP{sup SK} cells positive for established indicators of HSC presence: CD150{sup +} and CD105{sup +}. A great proportion of HSCs quickly but transiently enter the cell cycle to replenish the bone marrow of myelo-ablated mice. Ten weeks after, whereas bone marrow cellularity has recovered and hematopoietic homeostasis is restored, major phenotypic modifications can be observed within the Lin{sup -/low} Sca-1{sup +} c-Kit{sup +} (LSK) stem/progenitor compartment: CD150{sup +}/Flk2{sup -} and CD150{sup -}/Flk2{sup +} LSK cell frequencies are increased and dramatically reduced, respectively. CD150{sup +} LSK cells also show impaired reconstitution capacity, accrued number of {gamma}-H2AX foci and increased tendency to apoptosis. This demonstrates that the LSK compartment is not properly restored 10 weeks after sublethal exposure, and that long-term IR-induced injury to the bone marrow proceeds, at least partially, through direct damage to the stem cell pool. Thrombopoietin (TPO) has been shown to promote the survival of lethally irradiated mice when administrated quickly after exposure. We investigated the mechanisms underlying

  11. Restriction specificity of virus-specific cytotoxic T cells from thymectomised irradiated bone marrow chimeras reconstituted with thymus grafts

    International Nuclear Information System (INIS)

    Adult-thymectomised lethally irradiated mice A that were reconstituted with T-cell-depleted bone marrow cells of (A X B)F1 origin plus fetal thymus grafts of (B X C)F1 origin generated virus-specific T cells restricted to B alone; adult-thymectomised and lethally irradiated (A X B)F1 mice that were reconstituted with T-cell depleted bone marrow cells of (A X B)F1 origin plus fetal thymus grafts of A and of B origin generated virus-specific T cells restricted to A or to B. These results do not reveal obvious suppressive influences of host or stem-cell origin that might have explained results obtained with various irradiated bone marrow or thymus chimeras, they indicate that the thymus' influence on maturing T cells is one of the limiting steps in the selection of T cells' restriction specificities. (Auth.)

  12. Cancer cell specific cytotoxic gene expression mediated by ARF tumor suppressor promoter constructs

    International Nuclear Information System (INIS)

    Highlights: • ARF promoter showed higher responsiveness to deregulated E2F activity than the E2F1 promoter. • ARF promoter showed higher cancer cell-specificity than E2F1 promoter to drive gene expression. • HSV-TK driven by ARF promoter showed higher cancer cell-specific cytotoxicity than that driven by E2F1 promoter. - Abstract: In current cancer treatment protocols, such as radiation and chemotherapy, side effects on normal cells are major obstacles to radical therapy. To avoid these side effects, a cancer cell-specific approach is needed. One way to specifically target cancer cells is to utilize a cancer specific promoter to express a cytotoxic gene (suicide gene therapy) or a viral gene required for viral replication (oncolytic virotherapy). For this purpose, the selected promoter should have minimal activity in normal cells to avoid side effects, and high activity in a wide variety of cancers to obtain optimal therapeutic efficacy. In contrast to the AFP, CEA and PSA promoters, which have high activity only in a limited spectrum of tumors, the E2F1 promoter exhibits high activity in wide variety of cancers. This is based on the mechanism of carcinogenesis. Defects in the RB pathway and activation of the transcription factor E2F, the main target of the RB pathway, are observed in almost all cancers. Consequently, the E2F1 promoter, which is mainly regulated by E2F, has high activity in wide variety of cancers. However, E2F is also activated by growth stimulation in normal growing cells, suggesting that the E2F1 promoter may also be highly active in normal growing cells. In contrast, we found that the tumor suppressor ARF promoter is activated by deregulated E2F activity, induced by forced inactivation of pRB, but does not respond to physiological E2F activity induced by growth stimulation. We also found that the deregulated E2F activity, which activates the ARF promoter, is detected only in cancer cell lines. These observations suggest that ARF promoter

  13. Cancer cell specific cytotoxic gene expression mediated by ARF tumor suppressor promoter constructs

    Energy Technology Data Exchange (ETDEWEB)

    Kurayoshi, Kenta [Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 (Japan); Ozono, Eiko [Centre for Molecular Oncology, Barts Cancer Institute, Queen Mary, University of London, John Vane Science Centre, Charterhouse Square, London EC1M 6BQ (United Kingdom); Iwanaga, Ritsuko; Bradford, Andrew P. [Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045 (United States); Komori, Hideyuki [Center for Stem Cell Biology, Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109 (United States); Ohtani, Kiyoshi, E-mail: btm88939@kwansei.ac.jp [Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 (Japan)

    2014-07-18

    Highlights: • ARF promoter showed higher responsiveness to deregulated E2F activity than the E2F1 promoter. • ARF promoter showed higher cancer cell-specificity than E2F1 promoter to drive gene expression. • HSV-TK driven by ARF promoter showed higher cancer cell-specific cytotoxicity than that driven by E2F1 promoter. - Abstract: In current cancer treatment protocols, such as radiation and chemotherapy, side effects on normal cells are major obstacles to radical therapy. To avoid these side effects, a cancer cell-specific approach is needed. One way to specifically target cancer cells is to utilize a cancer specific promoter to express a cytotoxic gene (suicide gene therapy) or a viral gene required for viral replication (oncolytic virotherapy). For this purpose, the selected promoter should have minimal activity in normal cells to avoid side effects, and high activity in a wide variety of cancers to obtain optimal therapeutic efficacy. In contrast to the AFP, CEA and PSA promoters, which have high activity only in a limited spectrum of tumors, the E2F1 promoter exhibits high activity in wide variety of cancers. This is based on the mechanism of carcinogenesis. Defects in the RB pathway and activation of the transcription factor E2F, the main target of the RB pathway, are observed in almost all cancers. Consequently, the E2F1 promoter, which is mainly regulated by E2F, has high activity in wide variety of cancers. However, E2F is also activated by growth stimulation in normal growing cells, suggesting that the E2F1 promoter may also be highly active in normal growing cells. In contrast, we found that the tumor suppressor ARF promoter is activated by deregulated E2F activity, induced by forced inactivation of pRB, but does not respond to physiological E2F activity induced by growth stimulation. We also found that the deregulated E2F activity, which activates the ARF promoter, is detected only in cancer cell lines. These observations suggest that ARF promoter

  14. Open-Source Radiation Exposure Extraction Engine (RE3) with Patient-Specific Outlier Detection.

    Science.gov (United States)

    Weisenthal, Samuel J; Folio, Les; Kovacs, William; Seff, Ari; Derderian, Vana; Summers, Ronald M; Yao, Jianhua

    2016-08-01

    We present an open-source, picture archiving and communication system (PACS)-integrated radiation exposure extraction engine (RE3) that provides study-, series-, and slice-specific data for automated monitoring of computed tomography (CT) radiation exposure. RE3 was built using open-source components and seamlessly integrates with the PACS. RE3 calculations of dose length product (DLP) from the Digital imaging and communications in medicine (DICOM) headers showed high agreement (R (2) = 0.99) with the vendor dose pages. For study-specific outlier detection, RE3 constructs robust, automatically updating multivariable regression models to predict DLP in the context of patient gender and age, scan length, water-equivalent diameter (D w), and scanned body volume (SBV). As proof of concept, the model was trained on 811 CT chest, abdomen + pelvis (CAP) exams and 29 outliers were detected. The continuous variables used in the outlier detection model were scan length (R (2)  = 0.45), D w (R (2) = 0.70), SBV (R (2) = 0.80), and age (R (2) = 0.01). The categorical variables were gender (male average 1182.7 ± 26.3 and female 1047.1 ± 26.9 mGy cm) and pediatric status (pediatric average 710.7 ± 73.6 mGy cm and adult 1134.5 ± 19.3 mGy cm). PMID:26644157

  15. Non-specific chemical inhibition of the Fanconi anemia pathway sensitizes cancer cells to cisplatin

    Directory of Open Access Journals (Sweden)

    Jacquemont Céline

    2012-04-01

    Full Text Available Abstract Background Platinum compounds such as cisplatin and carboplatin are DNA crosslinking agents widely used for cancer chemotherapy. However, the effectiveness of platinum compounds is often tempered by the acquisition of cellular drug resistance. Until now, no pharmacological approach has successfully overcome cisplatin resistance in cancer treatment. Since the Fanconi anemia (FA pathway is a DNA damage response pathway required for cellular resistance to DNA interstrand crosslinking agents, identification of small molecules that inhibit the FA pathway may reveal classes of chemicals that sensitize cancer cells to cisplatin. Results Through a cell-based screening assay of over 16,000 chemicals, we identified 26 small molecules that inhibit ionizing radiation and cisplatin-induced FANCD2 foci formation, a marker of FA pathway activity, in multiple human cell lines. Most of these small molecules also compromised ionizing radiation-induced RAD51 foci formation and homologous recombination repair, indicating that they are not selective toward the regulation of FANCD2. These compounds include known inhibitors of the proteasome, cathepsin B, lysosome, CHK1, HSP90, CDK and PKC, and several uncharacterized chemicals including a novel proteasome inhibitor (Chembridge compound 5929407. Isobologram analyses demonstrated that half of the identified molecules sensitized ovarian cancer cells to cisplatin. Among them, 9 demonstrated increased efficiency toward FA pathway-proficient, cisplatin-resistant ovarian cancer cells. Six small molecules, including bortezomib (proteasome inhibitor, CA-074-Me (cathepsin B inhibitor and 17-AAG (HSP90 inhibitor, synergized with cisplatin specifically in FA-proficient ovarian cancer cells (2008 + FANCF, but not in FA-deficient isogenic cells (2008. In addition, geldanamycin (HSP90 inhibitor and two CHK1 inhibitors (UCN-01 and SB218078 exhibited a significantly stronger synergism with cisplatin in FA

  16. Study of Electromagnetic Radiation and Specific Absorption Rate of Mobile Phones with Fractional Human Head Models via Green's Functions

    Directory of Open Access Journals (Sweden)

    Nookala S. Rao

    2011-01-01

    Full Text Available Problem statement: Electromagnetic Radiation from mobile hand set is identified as one of the side effects for increasing rate of brain tumor. Due to this reason, Mobile phone industries are attentive towards safety issues of human health. Specific Absorption Rate is one of the important parameter while modeling the radiation effect on human head. Brain material with homogeneity is treated as an equivalent model of human head. The radiation caused by antennas mounted on mobile set is assumed to be monopolar. Approach: Apart from the Specific Absorption Rate, period of exposure to radiation is an extremely important parameter while assessing the effects on brain tissue. Correlation between the amount of radiation versus spherical model of brain is a complex phenomena, addressed in various simulation models. In the present work the field distribution inside the head are modeled using Dyadic Greens Functions while describing the effect of radiation pattern. Multilayered homogeneous lossy spherical model is proposed as an equivalent to head. Results: In this paper we present the depth of penetration of radiation and its effect on brain tissue. In essence the amount of electromagnetic power absorbed by biological tissues for various exposure conditions and types of emitting sources, utilizing a detailed model of the human head. Conclusion: Bio-heat equation is used to predict heat distribution inside the brain when exposed to radiation. The medium is assumed to be homogeneous, isotropic, linear, non dispersive and stationary. A critical evaluation of the method is discussed.

  17. Radiation signature on exposed cells: Relevance in dose estimation

    Institute of Scientific and Technical Information of China (English)

    Venkatachalam; Perumal; Tamizh; Selvan; Gnana; Sekaran; Venkateswarlu; Raavi; Safa; Abdul; Syed; Basheerudeen; Karthik; Kanagaraj; Amith; Roy; Chowdhury; Solomon; FD; Paul

    2015-01-01

    The radiation is considered as a double edged sword, as its beneficial and detrimental effects have been demonstrated. The potential benefits are being exploited to its maximum by adopting safe handling of radionuclide stipulated by the regulatory agencies. While the occupational workers are monitored by personnel monitoring devices, for general publics, it is not a regular practice. However, it can be achieved by using biomarkers with a potential for the radiation triage and medical management. An ideal biomarker to adopt in those situations should be rapid, specific, sensitive, reproducible, and able to categorize the nature of exposure and could provide a reliable dose estimation irrespective of the time of the exposures. Since cytogenetic markers shown to have many advantages relatively than other markers, the origins of various chromosomal abnormalities induced by ionizing radiations along with dose-response curves generated in the laboratory are presented. Current status of the gold standard dicentric chromosome assay, micronucleus assay, translocation measurement by fluorescence insitu hybridization and an emerging protein marker the g-H2 AX assay are discussed with our laboratory data. With the wide choice of methods, an appropriate assay can be employed based on the net.

  18. Radiation signature on exposed cells: Relevance in dose estimation.

    Science.gov (United States)

    Perumal, Venkatachalam; Gnana Sekaran, Tamizh Selvan; Raavi, Venkateswarlu; Basheerudeen, Safa Abdul Syed; Kanagaraj, Karthik; Chowdhury, Amith Roy; Paul, Solomon Fd

    2015-09-28

    The radiation is considered as a double edged sword, as its beneficial and detrimental effects have been demonstrated. The potential benefits are being exploited to its maximum by adopting safe handling of radionuclide stipulated by the regulatory agencies. While the occupational workers are monitored by personnel monitoring devices, for general publics, it is not a regular practice. However, it can be achieved by using biomarkers with a potential for the radiation triage and medical management. An ideal biomarker to adopt in those situations should be rapid, specific, sensitive, reproducible, and able to categorize the nature of exposure and could provide a reliable dose estimation irrespective of the time of the exposures. Since cytogenetic markers shown to have many advantages relatively than other markers, the origins of various chromosomal abnormalities induced by ionizing radiations along with dose-response curves generated in the laboratory are presented. Current status of the gold standard dicentric chromosome assay, micronucleus assay, translocation measurement by fluorescence in-situ hybridization and an emerging protein marker the γ-H2AX assay are discussed with our laboratory data. With the wide choice of methods, an appropriate assay can be employed based on the net. PMID:26435777

  19. Tract specific analysis in patients with sickle cell disease

    Science.gov (United States)

    Chai, Yaqiong; Coloigner, Julie; Qu, Xiaoping; Choi, Soyoung; Bush, Adam; Borzage, Matt; Vu, Chau; Lepore, Natasha; Wood, John

    2015-12-01

    Sickle cell disease (SCD) is a hereditary blood disorder in which the oxygen-carrying hemoglobin molecule in red blood cells is abnormal. It affects numerous people in the world and leads to a shorter life span, pain, anemia, serious infections and neurocognitive decline. Tract-Specific Analysis (TSA) is a statistical method to evaluate white matter alterations due to neurocognitive diseases, using diffusion tensor magnetic resonance images. Here, for the first time, TSA is used to compare 11 major brain white matter (WM) tracts between SCD patients and age-matched healthy subjects. Alterations are found in the corpus callosum (CC), the cortico-spinal tract (CST), inferior fronto-occipital fasciculus (IFO), inferior longitudinal fasciculus (ILF), superior longitudinal fasciculus (SLF), and uncinated fasciculus (UNC). Based on previous studies on the neurocognitive functions of these tracts, the significant areas found in this paper might be related to several cognitive impairments and depression, both of which are observed in SCD patients.

  20. Invasive oral cancer stem cells display resistance to ionising radiation.

    Science.gov (United States)

    Gemenetzidis, Emilios; Gammon, Luke; Biddle, Adrian; Emich, Helena; Mackenzie, Ian C

    2015-12-22

    There is a significant amount of evidence to suggest that human tumors are driven and maintained by a sub-population of cells, known as cancer stem cells (CSC). In the case of head and neck cancer, such cells have been characterised by high expression levels of CD44 cell surface glycoprotein, while we have previously shown the presence of two diverse oral CSC populations in vitro, with different capacities for cell migration and proliferation. Here, we examined the response of oral CSC populations to ionising radiation (IR), a front-line measure for the treatment of head and neck tumors. We show that oral CSC initially display resistance to IR-induced growth arrest as well as relative apoptotic resistance. We propose that this is a result of preferential activation of the DNA damagerepair pathway in oral CSC with increased activation of ATM and BRCA1, elevated levels of DNA repair proteins RAD52, XLF, and a significantly faster rate of DNA double-strand-breaks clearance 24 hours following IR. By visually identifying CSC sub-populations undergoing EMT, we show that EMT-CSC represent the majority of invasive cells, and are more radio-resistant than any other population in re-constructed 3D tissues. We provide evidence that IR is not sufficient to eliminate CSC in vitro, and that sensitization of CD44hi/ESAlow cells to IR, followed by secondary EMT blockade, could be critical in order to reduce primary tumor recurrence, but more importantly to be able to eradicate cells capable of invasion and distant metastasis.

  1. WT1-specific T cell receptor gene therapy: improving TCR function in transduced T cells.

    Science.gov (United States)

    Stauss, Hans J; Thomas, Sharyn; Cesco-Gaspere, Michela; Hart, Daniel P; Xue, Shao-An; Holler, Angelika; King, Judy; Wright, Graham; Perro, Mario; Pospori, Constantina; Morris, Emma

    2008-01-01

    Adoptive transfer of antigen-specific T lymphocytes is an attractive form of immunotherapy for haematological malignancies and cancer. The difficulty of isolating antigen-specific T lymphocytes for individual patients limits the more widespread use of adoptive T cell therapy. The demonstration that cloned T cell receptor (TCR) genes can be used to produce T lymphocyte populations of desired specificity offers new opportunities for antigen-specific T cell therapy. The first trial in humans demonstrated that TCR gene-modified T cells persisted for an extended time period and reduced tumor burden in some patients. The WT1 protein is an attractive target for immunotherapy of leukemia and solid cancer since elevated expression has been demonstrated in AML, CML, MDS and in breast, colon and ovarian cancer. In the past, we have isolated high avidity CTL specific for a WT1-derived peptide presented by HLA-A2 and cloned the TCR alpha and beta genes of a WT1-specific CTL line. The genes were inserted into retroviral vectors for transduction of human peripheral blood T lymphocytes of leukemia patients and normal donors. The treatment of leukemia-bearing NOD/SCID mice with T cells transduced with the WT1-specific TCR eliminated leukemia cells in the bone marrow of most mice, while treatment with T cells transduced with a TCR of irrelevant specificity did not diminish the leukemia burden. In order to improve the safety and efficacy of TCR gene therapy, we have developed lentiviral TCR gene transfer. In addition, we employed strategies to enhance TCR expression while avoiding TCR mis-pairing. It may be possible to generate dominant TCR constructs that can suppress the expression of the endogenous TCR on the surface of transduced T cells. The development of new TCR gene constructs holds great promise for the safe and effective delivery of TCR gene therapy for the treatment of malignancies. PMID:17855129

  2. Application of the inter-line PCR for the analyse of genomic rearrangements in radiation-transformed mammalian cell lines

    International Nuclear Information System (INIS)

    Repetitive DNA sequences of the LINE-family (long interspersed elements) that are widely distributed among the mammalian genome can be activated or altered by the exposure to ionizing radiation [1]. By the integration at new sites in the genome alterations in the expression of genes that are involved in cell transformation and/or carcinogenesis may occur [2, 3]. A new technique -the inter-LINE PCR - has been developed in order to detect and analyse such genomic rearrangements in radiation-transformed cell lines. From the sites of transformation- or tumour-specific changes in the genome it might be possible to develop new tumour markers for diagnostic purpose. (orig.)

  3. Silicon space solar cells: progression and radiation-resistance analysis

    Science.gov (United States)

    Rehman, Atteq ur; Lee, Sang Hee; Lee, Soo Hong

    2016-02-01

    In this paper, an overview of the solar cell technology based on silicon for applications in space is presented. First, the space environment and its effects on the basis of satellite orbits, such as geostationary earth orbit (GEO) and low earth orbit (LEO), are described. The space solar cell technology based on silicon-based materials, including thin-film silicon solar cells, for use in space was appraised. The evolution of the design for silicon solar cell for use in space, such as a backsurface field (BSF), selective doping, and both-side passivation, etc., is illustrated. This paper also describes the nature of radiation-induced defects and the models proposed for understanding the output power degradation in silicon space solar cells. The phenomenon of an anomalous increase in the short-circuit current ( I sc) in the fluence irradiation range from 2 × 1016 cm-2 to 5 × 1016 cm-2 is also described explicitly from the view point of the various presented models.

  4. The determination of mother cell-specific mating type of switching in yeast by a specific regulator of HO transcription

    OpenAIRE

    Nasmyth, Kim

    1987-01-01

    In haploid homothallic budding yeast, cell division gives rise to a mother cell which proceeds to switch its mating type and a daughter cell (the bud) which does not. Switching is initiated by a specific double strand cleavage of mating type DNA by an endonuclease encoded by the HO gene. Previous data suggest that the pattern of HO transcription is responsible for the mother cell specificity of switching. HO is transcribed transiently, at START, during the cell cycle of mother cells but not a...

  5. Response of hematopoietic stem cells to ionizing radiation

    International Nuclear Information System (INIS)

    Hematopoietic stem cells (HSCs) maintain blood and immune system throughout life and restore them after hematological injuries. Exposure of an organism to ionizing radiation (IR) causes rapid and acute myelosuppression and challenges the replenishment capacity of HSCs. Yet, the precise damages that are generated remain largely unexplored. To better understand these effects, phenotypic and functional changes in the stem/progenitor compartments of sublethally irradiated mice were monitored over a ten week period after radiation exposure. We report that shortly after sublethal IR-exposure, HSCs, defined by their repopulating ability, still segregate in the Hoechst dye excluding side population (SP); yet, their Sca-1 (S) and c-Kit (K) expression levels are increased and severely reduced, respectively, with a concurrent increase in the proportion of SPSK cells positive for established indicators of HSC presence: CD150+ and CD105+. A great proportion of HSCs quickly but transiently enter the cell cycle to replenish the bone marrow of myelo-ablated mice. Ten weeks after, whereas bone marrow cellularity has recovered and hematopoietic homeostasis is restored, major phenotypic modifications can be observed within the Lin-/low Sca-1+ c-Kit+ (LSK) stem/progenitor compartment: CD150+/Flk2- and CD150-/Flk2+ LSK cell frequencies are increased and dramatically reduced, respectively. CD150+ LSK cells also show impaired reconstitution capacity, accrued number of γ-H2AX foci and increased tendency to apoptosis. This demonstrates that the LSK compartment is not properly restored 10 weeks after sublethal exposure, and that long-term IR-induced injury to the bone marrow proceeds, at least partially, through direct damage to the stem cell pool. Thrombopoietin (TPO) has been shown to promote the survival of lethally irradiated mice when administrated quickly after exposure. We investigated the mechanisms underlying this effect, and found in a competitive transplant experiment that a

  6. The cell transmembrane pH gradient in tumors enhances cytotoxicity of specific weak acid chemotherapeutics.

    Science.gov (United States)

    Kozin, S V; Shkarin, P; Gerweck, L E

    2001-06-15

    The extracellular pH is lower in tumor than in normal tissue, whereas their intracellular pH is similar. In this study, we show that the tumor-specific pH gradient may be exploited for the treatment of cancer by weak acid chemotherapeutics. i.v.-injected glucose substantially decreased the electrode estimated extracellular pH in a xenografted human tumor while its intracellular pH, evaluated by (31)P magnetic resonance spectroscopy, remained virtually unchanged. The resulting increase in the average cell pH gradient caused a parallel increase in tumor growth delay by the weak acid chlorambucil (CHL). Regardless of glucose administration, the effect of CHL was significantly greater in tumors preirradiated with a large dose of ionizing radiation. This suggests that CHL was especially pronounced in radioresistant hypoxic cells possessing a larger transmembrane pH gradient. These results indicate that the naturally occurring cell pH gradient difference between tumor and normal tissue is a major and exploitable determinant of the uptake of weak acids in the complex tumor microenvironment. The use of such drugs may be especially effective in combination with radiation.

  7. Natural killer cells facilitate PRAME-specific T-cell reactivity against neuroblastoma.

    Science.gov (United States)

    Spel, Lotte; Boelens, Jaap-Jan; van der Steen, Dirk M; Blokland, Nina J G; van Noesel, Max M; Molenaar, Jan J; Heemskerk, Mirjam H M; Boes, Marianne; Nierkens, Stefan

    2015-11-01

    Neuroblastoma is the most common solid tumor in children with an estimated 5-year progression free survival of 20-40% in stage 4 disease. Neuroblastoma actively avoids recognition by natural killer (NK) cells and cytotoxic T lymphocytes (CTLs). Although immunotherapy has gained traction for neuroblastoma treatment, these immune escape mechanisms restrain clinical results. Therefore, we aimed to improve neuroblastoma immunogenicity to further the development of antigen-specific immunotherapy against neuroblastoma. We found that neuroblastoma cells significantly increase surface expression of MHC I upon exposure to active NK cells which thereby readily sensitize neuroblastoma cells for recognition by CTLs. We show that oncoprotein PRAME serves as an immunodominant antigen for neuroblastoma as NK-modulated neuroblastoma cells are recognized by PRAMESLLQHLIGL/A2-specific CTL clones. Furthermore, NK cells induce MHC I upregulation in neuroblastoma through contact-dependent secretion of IFNγ. Our results demonstrate remarkable plasticity in the peptide/MHC I surface expression of neuroblastoma cells, which is reversed when neuroblastoma cells experience innate immune attack by sensitized NK cells. These findings support the exploration of NK cells as adjuvant therapy to enforce neuroblastoma-specific CTL responses.

  8. Effects of Electromagnetic Radiation from Smartphones on Learning Ability and Hippocampal Progenitor Cell Proliferation in Mice

    OpenAIRE

    Choi, Yu-Jin; Choi, Yun-Sik

    2015-01-01

    Objectives Nonionizing radiation is emitted from electronic devices, such as smartphones. In this study, we intended to elucidate the effect of electromagnetic radiation from smartphones on spatial working memory and progenitor cell proliferation in the hippocampus. Methods Both male and female mice were randomly separated into two groups (radiated and control) and the radiated group was exposed to electromagnetic radiation for 9 weeks and 11 weeks for male and female mice, respectively. Spat...

  9. Genome-wide gene expression induced by ionizing radiation and hydrogen peroxide in human thyroid primary cultures and T-cells

    Energy Technology Data Exchange (ETDEWEB)

    Wersteyhe, S.; Driessens, N.; Tarabichi, M.; Dumont, J.E.; Miot, F.; Corvilain, B.; Detours, V. [IRIBHM, ULB, Brussels (Belgium)

    2012-07-01

    Ionizing radiation is an established cause of thyroid cancer and growing evidence supports a role for H{sub 2}O{sub 2} (hydrogen peroxide) in spontaneous thyroid carcinogenesis. The molecular programs activated by these two agents in the thyroid are not fully understood. We have profiled genome-wide gene expression induced by low dose {gamma}-radiation and H{sub 2}O{sub 2} in primary human thyroid cells, and also in T-cells in order to gain insight into cell type-specific effects. While {gamma}-radiation causes similar amounts of DNA damage and similar transcriptional responses in T-cells and thyroid cells, H{sub 2}O{sub 2} incurs less damage and a weaker transcriptional response in thyroid cells than in T-cells, suggesting that thyroid-specific protective mechanisms may be at work

  10. Genome-wide gene expression induced by ionizing radiation and hydrogen peroxide in human thyroid primary cultures and T-cells

    International Nuclear Information System (INIS)

    Ionizing radiation is an established cause of thyroid cancer and growing evidence supports a role for H2O2 (hydrogen peroxide) in spontaneous thyroid carcinogenesis. The molecular programs activated by these two agents in the thyroid are not fully understood. We have profiled genome-wide gene expression induced by low dose γ-radiation and H2O2 in primary human thyroid cells, and also in T-cells in order to gain insight into cell type-specific effects. While γ-radiation causes similar amounts of DNA damage and similar transcriptional responses in T-cells and thyroid cells, H2O2 incurs less damage and a weaker transcriptional response in thyroid cells than in T-cells, suggesting that thyroid-specific protective mechanisms may be at work

  11. Molecular basis of sidekick-mediated cell-cell adhesion and specificity

    Energy Technology Data Exchange (ETDEWEB)

    Goodman, Kerry M.; Yamagata, Masahito; Jin, Xiangshu; Mannepalli, Seetha; Katsamba, Phinikoula S.; Ahlsén, Göran; Sergeeva, Alina P.; Honig, Barry; Sanes, Joshua R.; Shapiro, Lawrence

    2016-09-19

    Sidekick (Sdk) 1 and 2 are related immunoglobulin superfamily cell adhesion proteins required for appropriate synaptic connections between specific subtypes of retinal neurons. Sdks mediate cell-cell adhesion with homophilic specificity that underlies their neuronal targeting function. Here we report crystal structures of Sdk1 and Sdk2 ectodomain regions, revealing similar homodimers mediated by the four N-terminal immunoglobulin domains (Ig1–4), arranged in a horseshoe conformation. These Ig1–4 horseshoes interact in a novel back-to-back orientation in both homodimers through Ig1:Ig2, Ig1:Ig1 and Ig3:Ig4 interactions. Structure-guided mutagenesis results show that this canonical dimer is required for both Sdk-mediated cell aggregation (viatransinteractions) and Sdk clustering in isolated cells (viacisinteractions). Sdk1/Sdk2 recognition specificity is encoded across Ig1–4, with Ig1–2 conferring the majority of binding affinity and differential specificity. We suggest that competition betweencisandtransinteractions provides a novel mechanism to sharpen the specificity of cell-cell interactions.

  12. Radiation stability of cations in ionic liquids. 5. Task-specific ionic liquids consisting of biocompatible cations and the puzzle of radiation hypersensitivity.

    Science.gov (United States)

    Shkrob, Ilya A; Marin, Timothy W; Wishart, James F; Grills, David C

    2014-09-01

    In 1953, an accidental discovery by Melvin Calvin and co-workers provided the first example of a solid (the α-polymorph of choline chloride) showing hypersensitivity to ionizing radiation: under certain conditions, the radiolytic yield of decomposition approached 5 × 10(4) per 100 eV (which is 4 orders of magnitude greater than usual values), suggesting an uncommonly efficient radiation-induced chain reaction. Twenty years later, the still-accepted mechanism for this rare condition was suggested by Martyn Symons, but no validation for this mechanism has been supplied. Meanwhile, ionic liquids and deep eutectic mixtures that are based on choline, betainium, and other derivitized natural amino compounds are presently finding an increasing number of applications as diluents in nuclear separations, where the constituent ions are exposed to ionizing radiation that is emitted by decaying radionuclides. Thus, the systems that are compositionally similar to radiation hypersensitive solids are being considered for use in high radiation fields, where this property is particularly undesirable! In Part 5 of this series on organic cations, we revisit the phenomenon of radiation hypersensitivity and explore mechanistic aspects of radiation-induced reactions involving this class of task-specific, biocompatible, functionalized cations, both in ionic liquids and in reference crystalline compounds. We demonstrate that Symons' mechanism needs certain revisions and rethinking, and suggest its modification. Our reconsideration suggests that there cannot be conditions leading to hypersensitivity in ionic liquids.

  13. Enhancement of radiation response in human cancer cells in vitro and in vivo by phytosphingosine

    International Nuclear Information System (INIS)

    Recent discoveries have revealed that sphingolipids (ceramide, sphingosine, sphingosine 1-phosphate, etc.) are highly bioactive compounds and are involved in diverse cell processes, including cell-cell interaction, cell proliferation, differentiation and apoptosis. However, the physiological roles of phytosphingosine are largely unknown. In the present study, we have investigated effect of phytosphingosine on anti-tumor activities of radiation in human cervical, breast, lung cancer cells and T cell lymphoma. Cells were treated with various concentrations of phytosphingosine and/or various doses of radiation. Phytosongosine sensitized cells in vitro and in vivo for treatment with ionizing radiation. Phytosphingosine in combination with ionizing radiation synergistically decreased clonogenic survival in a dose dependent manner. Similar to the result of clonogenic survival, in human cancer cells, combined treatment with phytosphingosine and ionizing radiation drastically induced apoptotic cell death. At dose levels of phytosphingosine with only minimal apoptotic effect, pretreatment of phytosphingosine synergistically enhanced ionizing radiation-induced apoptosis. Combined treatment with phytosphingosine and ionizing radiation resulted in an increased caspase family activation. In vivo, treatment of phytosphingosine (3 x 20 mg/kg) in combination with ionizing radiation exerted substantial tumor growth regression for human lung and cervical tumor xenograft. These results indicate that phytosphingosine can synergistically enhance radiosensitivity of human cancer cells in vitro and in vivo, suggesting a potential clinical application of combination treatment with phytosphingosine and ionizing radiation

  14. Intervention of oxygen-control ability to radiation sensitivity, cell aging and cell transformation

    International Nuclear Information System (INIS)

    Oxygen is essential for life, and cells have therefore developed numerous adaptive responses to oxygen change. Here, we examined the difference in oxygen-control functions of human (HE), mouse (ME), and Syrian hamster embryo (SHE) cells cultured under different oxygen conditions (0.5%, 2% and 20%), and also examined whether oxygen tensions contributed to cellular lifespan and transformation. HE cells had their replicative lifespan slightly extended under hypoxic (0.5% and 2% oxygen) conditions, but were not immortalized under any of the oxygen concentrations. On the other hand, although ME cells cultured under 20% oxygen tension decreased their proliferation potency temporarily at early stage, all rodent cells were immortalized and acquired anchorage-independency, regardless of oxygen tension. These results suggest that cellular oxygen control function is related to sensitivities cellular immortalization and transformation. To understand intervention of oxygen control ability on cellular immortalization and transformation, we examined the intracellular oxidative level, mitochondria functions and radiation sensitivity. Intracellular oxidative levels of hypoxically cultured rodent cells were significantly enhanced. Mitochondrial membrane potential was altered depend on oxygen tensions, but the change was not parallel to mitochondria number in rodent cells. ME cells were particularly sensitive to oxygen change, and showed a clear oxygen effect on the X-ray survival. However, there was no difference in frequency of radiation-induced micronuclei between HE and ME cells. These results suggest that the response to oxygen change differs markedly in HE and rodent cells. (author)

  15. Cancer Risk-Assessment of Radiation Damage in Ataxia Telangiectasia Heterozygous Human Breast Epithelial Cell Cultures

    Science.gov (United States)

    Applewhite, Lisa C.

    2002-01-01

    This paper describes the study of the markers of cellular changes that are found during the onset of carcinogenesis. Several of the biological factors are markers of stress response, oncoprotein expression, and differentiation factors. Oxidative stress response agents such as heat shock proteins (HSPs) protect cells from oxidative stresses such as ionizing radiation. The onocoprotein HER-2/neu, a specific breast cancer marker, indicates early onset of cancer. Additional structural and morphogenetic markers of differentiation were considered in order to determine initial cellular changes at the initial onset of cancer. As an additional consideration, all-trans retinoic acid (RA), a differentiation agent, was considered because of its known role in regulating normal differentiation and inhibiting tumor proliferation via specific nuclear receptors. This paper discusses study and results of the preliminary analyses of gamma irradiation of AT heterozygous human breast epithelial cells (WH). Comparisons are also made of the effects various RA concentrations post-irradiation.

  16. Specific cytotoxic T-cell immune responses against autoantigens recognized by chronic lymphocytic leukaemia cells.

    Science.gov (United States)

    Zaleska, Joanna; Skorka, Katarzyna; Zajac, Malgorzata; Karczmarczyk, Agnieszka; Karp, Marta; Tomczak, Waldemar; Hus, Marek; Wlasiuk, Paulina; Giannopoulos, Krzysztof

    2016-08-01

    Mounting evidence suggests that autoreactivity and inflammatory processes are involved in the pathogenesis of chronic lymphocytic leukaemia (CLL). Cytoskeletal proteins, including non-muscle myosin heavy chain IIA (MYHIIA), vimentin (VIM) and cofilin-1 (CFL1), exposed on the surface of apoptotic cells have been identified as autoantigens that are recognized by the specific B-cell receptors of the CLL cells. In 212 CLL patients analysed with quantitative reverse transcriptase-polymerase chain reaction we found CFL1 overexpression and low expression of MYH9 in comparison with healthy volunteers. We detected specific cytotoxic immune responses for peptides derived from MYHIIA in 66·7%, VIM in 87·5% and CFL1 in 62·5% CLL patients in an Enzyme-Linked ImmunoSpot assay. Low frequencies of autoreactive peptide-specific T cells were detected against MYHIIA, VIM and CFL1 in CLL patients ex vivo; most of the detected cells had an effector-memory phenotype. Our findings support the existence of cytotoxic immune responses against three autoantigens that have been identified as targets of CLL clonotypic B-cell receptors. The presence of autoreactive CD8(+) T cells against MYHIIA, VIM and CFL1 in CLL patients indicates the involvement of antigen-specific autoreactive T cells in the pathogenesis of CLL.

  17. Radiation-hardened gate-around n-MOSFET structure for radiation-tolerant application-specific integrated circuits

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Min Su; Lee, Hee Chul [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2012-11-15

    To overcome the total ionizing dose effect on an n-type metal-oxide-semiconductor field-effect transistor (n-MOSFET), we designed a radiation-hardened gate-around n-MOSFET structure and evaluated it through a radiation-exposure experiment. Each test device was fabricated in a commercial 0.35-micron complementary metal-oxide-semiconductor (CMOS) process. The fabricated devices were evaluated under a total dose of 1 Mrad (Si) at a dose rate of 250 krad/h to obtain very high reliability for space electronics. The experimental results showed that the gate-around n-MOSFET structure had very good performance against 1 Mrad (Si) of gamma radiation, while the conventional n-MOSFET experienced a considerable amount of radiation-induced leakage current. Furthermore, a source follower designed with the gate-around transistor worked properly at 1 Mrad (Si) of gamma radiation while a source follower designed with the conventional n-MOSFET lost its functionality.

  18. Human B cells produce chemokine CXCL10 in the presence of Mycobacterium tuberculosis specific T cells

    DEFF Research Database (Denmark)

    Hoff, Soren T; Salman, Ahmed M; Ruhwald, Morten;

    2015-01-01

    BACKGROUND: The role of B cells in human host response to Mycobacterium tuberculosis (Mtb) infection is still controversial, but recent evidence suggest that B cell follicle like structures within the lung may influence host responses through regulation of the local cytokine environment. A candid......BACKGROUND: The role of B cells in human host response to Mycobacterium tuberculosis (Mtb) infection is still controversial, but recent evidence suggest that B cell follicle like structures within the lung may influence host responses through regulation of the local cytokine environment...... appeared to be mediated via IFN-γ and dependent on contact with antigen-specific T cells recognizing the antigen. CONCLUSION: Human B cells are able to produce CXCL10 in an IFN-γ and T cell contact-dependent manner. The present findings suggest a possible mechanism through which B cells in part may...

  19. Gradual regeneration of mouse testicular stem cells after exposure to ionizing radiation

    International Nuclear Information System (INIS)

    The regeneration of mouse testicular stem cells during 60 weeks after exposure to 600 or 1200 rad of γ radiation was examined. Restoration of spermatogenesis depended on stem cell survival, regeneration, and differentiation. Several assays were employed to measure the number of stem cells and their ability to repopulate the seminiferous epithelium as follows. Assay 1: The percentage of repopulated tubular cross sections was determined histologically at various times after irradiation. Assay 2: Mice were irradiated and, after given time intervals to allow for regeneration of stem cell numbers, a second dose was given. The percentage of repopulated tubular cross sections was determined 5 weeks later. Assay 3: The ability of the stem cells to produce spermatocytes and spermatids was assayed by the levels of the germ cell specific isoenzyme, LDH-X. Assay 4: The ability of the stem cells to produce sperm was assayed by the number of sperm heads in the testes. In addition, the ability of the stem cells to produce functional spermatozoa was measured by the fertility of the animals. The results obtained were as follows. All assays demonstrated that gradual regeneration of stem cell number occurred simultaneously with repopulation of the seminiferous epithelium by differentiating cells derived from stem cells. The regeneration kinetics of stem cells followed an exponential increase approaching a dose-dependent plateau below the level prior to irradiation. The doubling time for stem cells during the exponential portion was about 2 weeks. The regeneration of stem cell number after depletion by irradiation was gradual and incomplete, and only partially restored spermatogenesis. Correlation of regeneration with fertility data demonstrated that fertility was reestablished when sperm production returned to about 15% of control levels

  20. 电离辐射诱导DNA-PKcs缺失小鼠T细胞特异的V(D)J 重组恢复%Restoration of T Cell-specific V(D)J Recombination in DNA-PKcs-/-Mice by Ionizing Radiation: The Effects on Survival,Development, and Tumorigenesis

    Institute of Scientific and Technical Information of China (English)

    李小玲; 沈守荣; 王飒; 欧阳红海; LI Gloria C

    2002-01-01

    DNA-dependent protein kinase (DNA-PK) is a DNA-activated nuclear serine/threonine protein kinase. DNA-PK consists of a heterodimeric Ku subunit (composed of a 70 and 86 kD subunit) which binds DNA ends and targets the catalytic subunit DNA-PKcs to DNA strand breaks. DNA-PK plays a major role in the repair of double-strand breaks (DSB) induced in DNA after exposure to ionizing radiation. To better understand the nature of DNA repair defect associated with DNA-PKcs deficiency, we have established DNA-PKcs-/- mouse embryo fibroblast cell lines and DNA-PKcs-/- null mice, and investigated the response of these mutant cells and mice to DNA damage. DNA-PKcs-/- cells are hypersensitive to γ-irradiation, as evidenced by their low survival as assayed by colony formation efficiencies. Consistent with the radiation hypersensitive phenotype of the cell lines, DNA-PKcs-/- mice also display an extreme radiosensitivity, characterized by enhanced mortality after γ-irradiation. Treatment of newborn DNA-PKcs-/- mice with sublethal doses of ionizing radiation restores T cell receptor (TCR)β recombination and T cell maturation. However, radiation does not restore B cell development. All these mice eventually developed thymic lymphoma. These observations suggest an interrelationship between DSB repair, V(D)J recombination and lymphomagenesis, and provide an in vivo model to elucidate the critical pathways between the regulation of DNA DSB repair, V(D)J recombination, and the molecular mechanism of lymphoid neoplasia.%DNA依赖的蛋白激酶(DNA-PK)是一种DNA活化的核丝氨酸苏氨酸蛋白激酶. DNA-PK 由一种与DNA末端结合的调节亚单位异构二聚体Ku蛋白和DNA-PK催化亚单位(DNA-PKcs)组成. DNA-PK 在DNA暴露于电离辐射后诱导的双链损伤修复中起主要作用. 为了更好地了解与DNA-PKcs缺失相关的DNA修复缺陷的本质. 建立了DNA-PKcs-/-小鼠胚胎成纤维细胞株和裸鼠模型, 调查这些突变的细

  1. Generation of patient-specific pluripotent stem cells and directed differentiation of embryonic stem cells for regenerative medicine

    Institute of Scientific and Technical Information of China (English)

    Minyue Ma; Jiahao Sha; Zuomin Zhou; Qi Zhou; Qingzhang Li

    2008-01-01

    Embryonic stem(ES) cells are pluripotent cells that can give rise to derivatives of all three embryonic germ layers. Due to its characteristics, the patient-specific ES cells are of great potential for transplantation therapies. Several strategies can reprogramme somatic cells back to pluripotent stem cells: nuclear transfer, fusion with ES cells, treatment with cell extract and induction by specific factors. Considering the future clinical use, the differentiation from ES to neurons, cardiomyocytes and many other types of cell scurrently provide basic cognition and experience to regenerative medicine. This article will review two courses, the reprogramming of differentiated cells and the differentiation of ES cells to specific cell types.

  2. Bistable cell fate specification as a result of stochastic fluctuations and collective spatial cell behaviour.

    Directory of Open Access Journals (Sweden)

    Daniel Stockholm

    Full Text Available BACKGROUND: In culture, isogenic mammalian cells typically display enduring phenotypic heterogeneity that arises from fluctuations of gene expression and other intracellular processes. This diversity is not just simple noise but has biological relevance by generating plasticity. Noise driven plasticity was suggested to be a stem cell-specific feature. RESULTS: Here we show that the phenotypes of proliferating tissue progenitor cells such as primary mononuclear muscle cells can also spontaneously fluctuate between different states characterized by the either high or low expression of the muscle-specific cell surface molecule CD56 and by the corresponding high or low capacity to form myotubes. Although this capacity is a cell-intrinsic property, the cells switch their phenotype under the constraints imposed by the highly heterogeneous microenvironment created by their own collective movement. The resulting heterogeneous cell population is characterized by a dynamic equilibrium between "high CD56" and "low CD56" phenotype cells with distinct spatial distribution. Computer simulations reveal that this complex dynamic is consistent with a context-dependent noise driven bistable model where local microenvironment acts on the cellular state by encouraging the cell to fluctuate between the phenotypes until the low noise state is found. CONCLUSIONS: These observations suggest that phenotypic fluctuations may be a general feature of any non-terminally differentiated cell. The cellular microenvironment created by the cells themselves contributes actively and continuously to the generation of fluctuations depending on their phenotype. As a result, the cell phenotype is determined by the joint action of the cell-intrinsic fluctuations and by collective cell-to-cell interactions.

  3. Gene Mutation as Biomarker of Radiation Induced Cell Injury and Genomic Instability

    Directory of Open Access Journals (Sweden)

    M Syaifudin

    2006-07-01

    Full Text Available Gene expression profiling and its mutation has become one of the most widely used approaches to identify genes and their functions in the context of identify and categorize genes to be used as radiation effect markers including cell and tissue sensitivities. Ionizing radiation produces genetic damage and changes in gene expression that may lead to cancer due to specific protein that controlling cell proliferation altered the function, its expression or both. P53 protein encoded by p53 gene plays an important role in protecting cell by inducing growth arrest and or cell suicide (apoptosis after deoxyribonucleic acid (DNA damage induced by mutagen such as ionizing radiation. The mutant and thereby dysfunctional of this gene was found in more than 50% of various human cancers, but it is as yet unclear how p53 mutations lead to neoplastic development. Wild-type p53 has been postulated to play a role in DNA repair, suggesting that expression of mutant forms of p53 might alter cellular resistance to the DNA damage caused by radiation. Moreover, p53 is thought to function as a cell cycle checkpoint after irradiation, also suggesting that mutant p53 might change the cellular proliferative response to radiation. p53 mutations affect the cellular response to DNA damage, either by increasing DNA repair processes or, possibly, by increasing cellular tolerance to DNA damage. The association of p53 mutations with increased radioresistance suggests that alterations in the p53 gene might lead to oncogenic transformation. Current attractive model of carcinogenesis also showed that p53 gene is the major target of radiation. The majority of p53 mutations found so far is single base pairchanges (point mutations, which result in amino acid substitutionsor truncated forms of the P53 protein, and are widely distributedthroughout the evolutionarily conserved regions of the gene. Examination of p53 mutations in human cancer also shows an association between particular

  4. Semiallogenic fusions of MSI+ tumor cells and activated B cells induce MSI-specific T cell responses

    Directory of Open Access Journals (Sweden)

    Klier Ulrike

    2011-09-01

    Full Text Available Abstract Background Various strategies have been developed to transfer tumor-specific antigens into antigen presenting cells in order to induce cytotoxic T cell responses against tumor cells. One approach uses cellular vaccines based on fusions of autologous antigen presenting cells and allogeneic tumor cells. The fusion cells combine antigenicity of the tumor cell with optimal immunostimulatory capacity of the antigen presenting cells. Microsatellite instability caused by mutational inactivation of DNA mismatch repair genes results in translational frameshifts when affecting coding regions. It has been shown by us and others that these mutant proteins lead to the presentation of immunogenic frameshift peptides that are - in principle - recognized by a multiplicity of effector T cells. Methods We chose microsatellite instability-induced frameshift antigens as ideal to test for induction of tumor specific T cell responses by semiallogenic fusions of microsatellite instable carcinoma cells with CD40-activated B cells. Two fusion clones of HCT116 with activated B cells were selected for stimulation of T cells autologous to the B cell fusion partner. Outgrowing T cells were phenotyped and tested in functional assays. Results The fusion clones expressed frameshift antigens as well as high amounts of MHC and costimulatory molecules. Autologous T cells stimulated with these fusions were predominantly CD4+, activated, and reacted specifically against the fusion clones and also against the tumor cell fusion partner. Interestingly, a response toward 6 frameshift-derived peptides (of 14 tested could be observed. Conclusion Cellular fusions of MSI+ carcinoma cells and activated B cells combine the antigen-presenting capacity of the B cell with the antigenic repertoire of the carcinoma cell. They present frameshift-derived peptides and can induce specific and fully functional T cells recognizing not only fusion cells but also the carcinoma cells. These

  5. Kinetics of antigen specific and non-specific polyclonal B-cell responses during lethal Plasmodium yoelii malaria

    Directory of Open Access Journals (Sweden)

    Laurence Rolland

    1992-06-01

    Full Text Available In order to study the kinetics and composition of the polyclonal B-cell activation associated to malaria infection, antigen-specific and non-specific B-cell responses were evaluated in the spleens of mice infected with Plasmodium yoelii 17 XL or injected with lysed erythrocytes or plasma from P. yoelii infected mice or with P. falciparum culture supernatants. Spleen/body weigth ratio, numbers of nucleated spleen cells and Immunoglobulin-containing and Immunoglobulin-secreting cells increased progressively during the course of infection,in parallel to the parasitemia. A different pattern of kinetics was observed when anti-sheep red blood cell and anti-trinitrophenylated-sheep red blood cell plaque forming cells response were studied: maximum values were observed at early stages of infection, whereas the number of total Immunoglobulin-containing and Immunoglobulin-secreting cells were not yet altered. Conversely, at the end of infection, when these latter values reached their maximum, the anti-sheep red blood cell and anti-trinitrophenylated-sheep red blood cell specific responses were normal or even infranormal. In mice injected with Plasmodium-derived material, a higher increase in antigen-specific PFC was observed, as compared to the increase of Immunoglobulin-containing and Immunoglobulin-secreting cell numbers. This suggested a "preferential" (antigen-plus mitogen-induced stimulation of antigen-specific cells rather than a generalized non-specific (mitogen-induced triggering of B-lymphocytes. On the basis of these and previous results, it is suggested that polyclonal B-cell activation that takes place during the course of infection appears as a result of successive waves of antigen-specific B-cell activation.

  6. Cleavage patterns, cell-lineages and cell specification are clues to phyletic lineages in Spiralia.

    Science.gov (United States)

    van den Biggelaar, J A; Dictus, W J; van Loon, A E

    1997-08-01

    Embryos of molluscs, annelids, nemerteans and platyhelminthes show remarkable intra- and interphyletic resemblances and differences in mesentoblast, dorso-ventral axis and trochoblast specification. These variations have been used to investigate their evolutionary relationship. In molluscs and annelids a heterochronic shift parallels evolutionary relations based on adult characters. Nemerteans and platyhelminthes lack trochal cells and differ in the specification of the mesodermal precursor cell. Nemerteans also differ fundamentally with respect to axis specification related to the first cleavage. Therefore, close phylogenetic relations exist between molluscs and annelids, whereas nemerteans and platyhelminthes are only remotely related with each other and with molluscs and annelids. PMID:15001075

  7. Cell-specific modulation of surfactant proteins by ambroxol treatment.

    Science.gov (United States)

    Seifart, Carola; Clostermann, Ursula; Seifart, Ulf; Müller, Bernd; Vogelmeier, Claus; von Wichert, Peter; Fehrenbach, Heinz

    2005-02-15

    Ambroxol [trans-4-(2-amino-3,5-dibromobenzylamino)-cyclohexanole hydrochloride], a mucolytic agent, was postulated to provide surfactant stimulatory properties and was previously used to prevent surfactant deficiency. Currently, the underlying mechanisms are not exactly clear. Because surfactant homeostasis is regulated by surfactant-specific proteins (SP), we analyzed protein amount and mRNA expression in whole lung tissue, isolated type II pneumocytes and bronchoalveolar lavage of Sprague-Dawley rats treated with ambroxol i.p. (75 mg/kg body weight, twice a day [every 12 h]). The methods used included competitive polymerase chain reaction (RT-PCR), Northern blotting, Western immunoblotting, and immunohistochemistry. In isolated type II pneumocytes of ambroxol-treated animals, SP-C protein and mRNA content were increased, whereas SP-A, -B and -D protein, mRNA, and immunoreactivity remained unaffected. However, ambroxol treatment resulted in a significant increase of SP-B and in a decrease of SP-D in whole lung tissue with enhanced immunostaining for SP-B in Clara Cells. SP-A and SP-D were significantly decreased in BAL fluid of ambroxol-treated animals. The data suggest that surfactant protein expression is modulated in a cell-specific manner by ambroxol, as type II pneumocytes exhibited an increase in SP-C, whereas Clara cells exhibited an increase in the immunoreactivity for SP-B accounting for the increased SP-B content of whole lung tissue. The results indicate that ambroxol may exert its positive effects, observed in the treatment of diseases related to surfactant deficiency, via modulation of surfactant protein expression.

  8. Cell-specific modulation of surfactant proteins by ambroxol treatment

    International Nuclear Information System (INIS)

    Ambroxol [trans-4-(2-amino-3,5-dibromobenzylamino)-cyclohexanole hydrochloride], a mucolytic agent, was postulated to provide surfactant stimulatory properties and was previously used to prevent surfactant deficiency. Currently, the underlying mechanisms are not exactly clear. Because surfactant homeostasis is regulated by surfactant-specific proteins (SP), we analyzed protein amount and mRNA expression in whole lung tissue, isolated type II pneumocytes and bronchoalveolar lavage of Sprague-Dawley rats treated with ambroxol i.p. (75 mg/kg body weight, twice a day [every 12 h]). The methods used included competitive polymerase chain reaction (RT-PCR), Northern blotting, Western immunoblotting, and immunohistochemistry. In isolated type II pneumocytes of ambroxol-treated animals, SP-C protein and mRNA content were increased, whereas SP-A, -B and -D protein, mRNA, and immunoreactivity remained unaffected. However, ambroxol treatment resulted in a significant increase of SP-B and in a decrease of SP-D in whole lung tissue with enhanced immunostaining for SP-B in Clara Cells. SP-A and SP-D were significantly decreased in BAL fluid of ambroxol-treated animals. The data suggest that surfactant protein expression is modulated in a cell-specific manner by ambroxol, as type II pneumocytes exhibited an increase in SP-C, whereas Clara cells exhibited an increase in the immunoreactivity for SP-B accounting for the increased SP-B content of whole lung tissue. The results indicate that ambroxol may exert its positive effects, observed in the treatment of diseases related to surfactant deficiency, via modulation of surfactant protein expression

  9. MarCell trademark software for modeling bone marrow radiation cell kinetics

    International Nuclear Information System (INIS)

    Differential equations were used to model cellular injury, repair, and compensatory proliferation in the irradiated bone marrow. Recently, that model was implemented as MarCell trademark, a user-friendly MS-DOS computer program that allows users from a variety of technical disciplines to evaluate complex radiation exposure. The software allows menu selections for different sources of ionizing radiation. Choices for cell lineages include progenitor, stroma, and malignant, and the available species include mouse, rat, dog, sheep, swine, burro, and man. An attractive feature is that any protracted irradiation can be compared with an equivalent prompt dose (EPD) in terms of cell kinetics for either the source used or for a reference such as 250 kVp x rays or 60Co. EPD is used to mean a dose rate for which no meaningful biological recovery occurs during the period of irradiation. For human as species, output from MarCell trademark includes: risk of 30-day mortality; risk of whole-body cancer and leukemia based either on radiation-induced cytopenia or compensatory cell proliferation; cell survival and repopulation plots as functions of time or dose; and 4-week recovery following treatment. copyright 1997 American Association of Physicists in Medicine

  10. Physico-chemical studies of radiation effects in cells. Progress report, November 15, 1980-February 14, 1984

    International Nuclear Information System (INIS)

    The primary interest is investigating and understanding the chemical mechanisms involved in radiation-induced cellular damage. Most recently the perturbating devices have been metals which increase, in various ways and modes, the radiation sensitivity of several cell types. While the chief cell type has been the bacterial spore, chosen because of its biological inertness and its hardiness, allowing it to survive the unphysiological conditions of the physical chemist and, thus, inquiry into the free radical mechanisms involved very soon after energy absorption, recently vegetative cells have been introduced. A number of metals have been used and practically all of them sensitize - but to varying degrees. Straight biological techniques such as the measurement of cell survival under various conditions in the different cells have been used, as well as parallel experiments in pulse radiolysis to attack the specific leads in a chemical fashion suggested by the biology

  11. Cell-of-Origin-Specific 3D Genome Structure Acquired during Somatic Cell Reprogramming

    Science.gov (United States)

    Krijger, Peter Hugo Lodewijk; Di Stefano, Bruno; de Wit, Elzo; Limone, Francesco; van Oevelen, Chris; de Laat, Wouter; Graf, Thomas

    2016-01-01

    Summary Forced expression of reprogramming factors can convert somatic cells into induced pluripotent stem cells (iPSCs). Here we studied genome topology dynamics during reprogramming of different somatic cell types with highly distinct genome conformations. We find large-scale topologically associated domain (TAD) repositioning and alterations of tissue-restricted genomic neighborhoods and chromatin loops, effectively erasing the somatic-cell-specific genome structures while establishing an embryonic stem-cell-like 3D genome. Yet, early passage iPSCs carry topological hallmarks that enable recognition of their cell of origin. These hallmarks are not remnants of somatic chromosome topologies. Instead, the distinguishing topological features are acquired during reprogramming, as we also find for cell-of-origin-dependent gene expression patterns. PMID:26971819

  12. Engineering antigen-specific T cells from genetically modified human hematopoietic stem cells in immunodeficient mice.

    Directory of Open Access Journals (Sweden)

    Scott G Kitchen

    Full Text Available There is a desperate need for effective therapies to fight chronic viral infections. The immune response is normally fastidious at controlling the majority of viral infections and a therapeutic strategy aimed at reestablishing immune control represents a potentially powerful approach towards treating persistent viral infections. We examined the potential of genetically programming human hematopoietic stem cells to generate mature CD8+ cytotoxic T lymphocytes that express a molecularly cloned, "transgenic" human anti-HIV T cell receptor (TCR. Anti-HIV TCR transduction of human hematopoietic stem cells directed the maturation of a large population of polyfunctional, HIV-specific CD8+ cells capable of recognizing and killing viral antigen-presenting cells. Thus, through this proof-of-concept we propose that genetic engineering of human hematopoietic stem cells will allow the tailoring of effector T cell responses to fight HIV infection or other diseases that are characterized by the loss of immune control.

  13. Molecular characterization of a complex site-specific radiation-induced DNA double-strand break

    International Nuclear Information System (INIS)

    Full text: Radiation lethality is a function of radiation-induced DNA double-strand breaks (DSB). Current models propose the lethality of a DSB to be a function of its structural complexity. We present here for the first time a map of damage associated with a site-specific double-strand break produced by decay of 125I in a plasmid bound by a 125I-labeled triplex forming oligonucleotide (125 I-TFO). The E. coli DNA repair enzymes, endonuclease IV (endo IV), endonuclease III (endo III), and formamidopyrimidine-DNA glycosylase (Fpg), which recognize AP sites, and pyrimidine and purine base damage respectively, were used as probes in this study. 125I-TFO bound plasmid was incubated with and without DMSO at -80 deg C for 1 month. No significant difference in DSB yield was observed under these conditions. A 32 base pair fragment from the upstream side of the decay site was isolated by restriction digestion and enzymatically probed to identify damage sites. Endo IV treatment of the 5'-end labeled upper strand indicated clustering of AP sites within 3 bases downstream and 7 bases upstream of the targeted base. Also, repeated experiments consistently detected an AP site 4 bases upstream of the 125 I target base. This was further supported by complementary results with the 3'-end labeled upper strand. Endo IV analysis of the lower strand also shows clustering of AP sites near the DSB end. Endo III and Fpg probing demonstrated that base damage is also clustered near the targeted break site. DSBs produced in the absence of DMSO displayed a different pattern of enzyme sensitive damage than those produced in the presence of DMSO. Identification of specific base damage types within the restriction fragment containing the DSB end was achieved with GC/MS. Base damage consisted of 8-hydroguanine, 8-hydroxyadenine, and 5-hydroxycytosine. These lesions were observed at relative yields of 8-hydroguanine and 5-hydroxycytosine to 8-hydroxyadenine of 7.4:1 and 4.7:1, respectively, in the

  14. Molecular characterization of a complex site-specific radiation-induced DNA double-strand break

    International Nuclear Information System (INIS)

    Radiation lethality is a function of radiation-induced DNA double-strand breaks (DSB). Current models propose the lethality of a DSB to be a function of its structural complexity. We present here for the first time a map of damage associated with a site-specific double-strand break produced by decay of 125I in a plasmid bound by a 125I-labeled triplex forming oligonucleotide ( 125I-TFO). The E. coli DNA repair enzymes, endonuclease IV (endo IV), endonuclease III (endo III), and formamidopyrimidine-DNA glycosylase (Fpg), which recognize AP sites, and pyrimidine and purine base damage respectively, were used as probes in this study. 125I-TFO bound plasmid was incubated with and without DMSO at -80 deg C for 1 month. No significant difference in DSB yield was observed under these conditions. A 32 base pair fragment from the upstream side of the decay site was isolated by restriction digestion and enzymatically probed to identify damage sites. Endo IV treatment of the 5'-end labeled upper strand indicated clustering of AP sites within 3 bases downstream and 7 bases upstream of the targeted base. Also, repeated experiments consistently detected an AP site 4 bases upstream of the 125Itarget base. This was further supported by complementary results with the 3'-end labeled upper strand. Endo IV analysis of the lower strand also shows clustering of AP sites near the DSB end. Endo III and Fpg probing demonstrated that base damage is also clustered near the targeted break site. DSBs produced in the absence of DMSO displayed a different pattern of enzyme sensitive damage than those produced in the presence of DMSO. Identification of specific base damage types within the restriction fragment containing the DSB end was achieved with GC/MS. Base damage consisted of 8-hydroguanine, 8-hydroxyadenine, and 5-hydroxycytosine. These lesions were observed at relative yields of 8-hydroguanine and 5-hydroxycytosine to 8-hydroxyadenine of 7.4:1 and 4.7:1, respectively, in the absence of

  15. Human antigen-specific regulatory T cells generated by T cell receptor gene transfer.

    Directory of Open Access Journals (Sweden)

    Todd M Brusko

    Full Text Available BACKGROUND: Therapies directed at augmenting regulatory T cell (Treg activities in vivo as a systemic treatment for autoimmune disorders and transplantation may be associated with significant off-target effects, including a generalized immunosuppression that may compromise beneficial immune responses to infections and cancer cells. Adoptive cellular therapies using purified expanded Tregs represents an attractive alternative to systemic treatments, with results from animal studies noting increased therapeutic potency of antigen-specific Tregs over polyclonal populations. However, current methodologies are limited in terms of the capacity to isolate and expand a sufficient quantity of endogenous antigen-specific Tregs for therapeutic intervention. Moreover, FOXP3+ Tregs fall largely within the CD4+ T cell subset and are thus routinely MHC class II-specific, whereas class I-specific Tregs may function optimally in vivo by facilitating direct tissue recognition. METHODOLOGY/PRINCIPAL FINDINGS: To overcome these limitations, we have developed a novel means for generating large numbers of antigen-specific Tregs involving lentiviral T cell receptor (TCR gene transfer into in vitro expanded polyclonal natural Treg populations. Tregs redirected with a high-avidity class I-specific TCR were capable of recognizing the melanoma antigen tyrosinase in the context of HLA-A*0201 and could be further enriched during the expansion process by antigen-specific reactivation with peptide loaded artificial antigen presenting cells. These in vitro expanded Tregs continued to express FOXP3 and functional TCRs, and maintained the capacity to suppress conventional T cell responses directed against tyrosinase, as well as bystander T cell responses. Using this methodology in a model tumor system, murine Tregs designed to express the tyrosinase TCR effectively blocked antigen-specific effector T cell (Teff activity as determined by tumor cell growth and luciferase reporter

  16. Effects of Chronic Low-Dose Radiation on Human Neural Progenitor Cells

    Science.gov (United States)

    Katsura, Mari; Cyou-Nakamine, Hiromasa; Zen, Qin; Zen, Yang; Nansai, Hiroko; Amagasa, Shota; Kanki, Yasuharu; Inoue, Tsuyoshi; Kaneki, Kiyomi; Taguchi, Akashi; Kobayashi, Mika; Kaji, Toshiyuki; Kodama, Tatsuhiko; Miyagawa, Kiyoshi; Wada, Youichiro; Akimitsu, Nobuyoshi; Sone, Hideko

    2016-01-01

    The effects of chronic low-dose radiation on human health have not been well established. Recent studies have revealed that neural progenitor cells are present not only in the fetal brain but also in the adult brain. Since immature cells are generally more radiosensitive, here we investigated the effects of chronic low-dose radiation on cultured human neural progenitor cells (hNPCs) derived from embryonic stem cells. Radiation at low doses of 31, 124 and 496 mGy per 72 h was administered to hNPCs. The effects were estimated by gene expression profiling with microarray analysis as well as morphological analysis. Gene expression was dose-dependently changed by radiation. By thirty-one mGy of radiation, inflammatory pathways involving interferon signaling and cell junctions were altered. DNA repair and cell adhesion molecules were affected by 124 mGy of radiation while DNA synthesis, apoptosis, metabolism, and neural differentiation were all affected by 496 mGy of radiation. These in vitro results suggest that 496 mGy radiation affects the development of neuronal progenitor cells while altered gene expression was observed at a radiation dose lower than 100 mGy. This study would contribute to the elucidation of the clinical and subclinical phenotypes of impaired neuronal development induced by chronic low-dose radiation. PMID:26795421

  17. Effects of Chronic Low-Dose Radiation on Human Neural Progenitor Cells

    Science.gov (United States)

    Katsura, Mari; Cyou-Nakamine, Hiromasa; Zen, Qin; Zen, Yang; Nansai, Hiroko; Amagasa, Shota; Kanki, Yasuharu; Inoue, Tsuyoshi; Kaneki, Kiyomi; Taguchi, Akashi; Kobayashi, Mika; Kaji, Toshiyuki; Kodama, Tatsuhiko; Miyagawa, Kiyoshi; Wada, Youichiro; Akimitsu, Nobuyoshi; Sone, Hideko

    2016-01-01

    The effects of chronic low-dose radiation on human health have not been well established. Recent studies have revealed that neural progenitor cells are present not only in the fetal brain but also in the adult brain. Since immature cells are generally more radiosensitive, here we investigated the effects of chronic low-dose radiation on cultured human neural progenitor cells (hNPCs) derived from embryonic stem cells. Radiation at low doses of 31, 124 and 496 mGy per 72 h was administered to hNPCs. The effects were estimated by gene expression profiling with microarray analysis as well as morphological analysis. Gene expression was dose-dependently changed by radiation. By thirty-one mGy of radiation, inflammatory pathways involving interferon signaling and cell junctions were altered. DNA repair and cell adhesion molecules were affected by 124 mGy of radiation while DNA synthesis, apoptosis, metabolism, and neural differentiation were all affected by 496 mGy of radiation. These in vitro results suggest that 496 mGy radiation affects the development of neuronal progenitor cells while altered gene expression was observed at a radiation dose lower than 100 mGy. This study would contribute to the elucidation of the clinical and subclinical phenotypes of impaired neuronal development induced by chronic low-dose radiation.

  18. Cardiomyocyte expression and cell-specific processing of procholecystokinin

    DEFF Research Database (Denmark)

    Gøtze, Jens P.; Johnsen, Anders H.; Kistorp, Caroline;

    2015-01-01

    Heart muscle cells produce peptide hormones such as natriuretic peptides. Developing hearts also express the gene for the classic intestinal hormone cholecystokinin (CCK) in amounts similar to those in the intestine and brain. However, cardiac expression of peptides other than natriuretic peptides...... has only been suggested using transcriptional measures or methods, with the post-translational phase of gene expression unaddressed. In this study, we examined the cardiac expression of the CCK gene in adult mammals and its expression at the protein level. Using quantitative PCR, a library of sequence......-specific pro-CCK assays, peptide purification, and mass spectrometry, we demonstrate that the mammalian heart expresses pro-CCK in amounts comparable to natriuretic prohormones and processes it to a unique, triple-sulfated, and N-terminally truncated product distinct from intestinal and cerebral CCK peptides...

  19. Imaging and radiation effects of gold nanoparticles in tumour cells

    Science.gov (United States)

    McQuaid, Harold N.; Muir, Mark F.; Taggart, Laura E.; McMahon, Stephen J.; Coulter, Jonathan A.; Hyland, Wendy B.; Jain, Suneil; Butterworth, Karl T.; Schettino, Giuseppe; Prise, Kevin M.; Hirst, David G.; Botchway, Stanley W.; Currell, Fred J.

    2016-01-01

    Gold nanoparticle radiosensitization represents a novel technique in enhancement of ionising radiation dose and its effect on biological systems. Variation between theoretical predictions and experimental measurement is significant enough that the mechanism leading to an increase in cell killing and DNA damage is still not clear. We present the first experimental results that take into account both the measured biodistribution of gold nanoparticles at the cellular level and the range of the product electrons responsible for energy deposition. Combining synchrotron-generated monoenergetic X-rays, intracellular gold particle imaging and DNA damage assays, has enabled a DNA damage model to be generated that includes the production of intermediate electrons. We can therefore show for the first time good agreement between the prediction of biological outcomes from both the Local Effect Model and a DNA damage model with experimentally observed cell killing and DNA damage induction via the combination of X-rays and GNPs. However, the requirement of two distinct models as indicated by this mechanistic study, one for short-term DNA damage and another for cell survival, indicates that, at least for nanoparticle enhancement, it is not safe to equate the lethal lesions invoked in the local effect model with DNA damage events.

  20. Results of radiation therapy for squamous cell carcinoma of vulva

    Energy Technology Data Exchange (ETDEWEB)

    Tsukiyama, Iwao; Kakehi, Masae; Ono, Ryosuke (National Cancer Center, Tokyo (Japan). Hospital)

    1984-04-01

    From 1962 to 1982, 20 cases of patients with squamous cell carcinoma of the vulva were treated by radiation alone at National Cancer Center Hospital, Tokyo. 80% (16/20) of these cases were over 60 years old. Treatment was made by interstitial irradiation (Radium needle or Au-Grain) and external irradiation (Betatron electron or Linac X-rays), alone or with various combinations. As for the stage of these cases, Stage I was 3 cases (15%), Stage II was 5 (25%) and Stage III was 12 (60%). Serious complications after treatment were observed in 15% (3/20) and all cases were treated with external irradiation alone. The 5 year survival rates by stage were as follows; Stage I 100% (3/3), Stage II 50% (2/4) and Stage III 22.2% (2/9). Surgery is considered the treatment of choice in this disease. However, radiation therapy may be indicated when the tumor has extended beyond the limit of surgical resections; when distant metastases are present; when the patient's general condition precludes surgery, or when surgery is refused.

  1. Results of radiation therapy for squamous cell carcinoma of vulva

    International Nuclear Information System (INIS)

    From 1962 to 1982, 20 cases of patients with squamous cell carcinoma of the vulva were treated by radiation alone at National Cancer Center Hospital, Tokyo. 80% (16/20) of these cases were over 60 years old. Treatment was made by interstitial irradiation (Radium needle or Au-Grain) and external irradiation (Betatron electron or Linac X-rays), alone or with various combinations. As for the stage of these cases, Stage I was 3 cases (15%), Stage II was 5 (25%) and Stage III was 12 (60%). Serious complications after treatment were observed in 15% (3/20) and all cases were treated with external irradiation alone. The 5 year survival rates by stage were as follows; Stage I 100% (3/3), Stage II 50% (2/4) and Stage III 22.2% (2/9). Surgery is considered the treatment of choice in this disease. However, radiation therapy may be indicated when the tumor has extended beyond the limit of surgical resections; when distant metastases are present; when the patient's general condition precludes surgery, or when surgery is refused. (author)

  2. GaAs quantum dot solar cell under concentrated radiation

    International Nuclear Information System (INIS)

    Effects of concentrated solar radiation on photovoltaic performance are investigated in well-developed GaAs quantum dot (QD) solar cells with 1-Sun efficiencies of 18%–19%. In these devices, the conversion processes are enhanced by nanoscale potential barriers and/or AlGaAs atomically thin barriers around QDs, which prevent photoelectron capture to QDs. Under concentrated radiation, the short circuit current increases proportionally to the concentration and the open circuit voltage shows the logarithmic increase. In the range up to hundred Suns, the contributions of QDs to the photocurrent are proportional to the light concentration. The ideality factors of 1.1–1.3 found from the VOC-Sun characteristics demonstrate effective suppression of recombination processes in barrier-separated QDs. The conversion efficiency shows the wide maximum in the range of 40–90 Suns and reaches 21.6%. Detailed analysis of I-V-Sun characteristics shows that at low intensities, the series resistance decreases inversely proportional to the concentration and, at ∼40 Suns, reaches the plateau determined mainly by the front contact resistance. Improvement of contact resistance would increase efficiency to above 24% at thousand Suns

  3. On the cell biology of pit cells, the liver-specific NK cells

    Institute of Scientific and Technical Information of China (English)

    Dian Zhong Luo; David Vermijlen; Bülent Ahishali; Vasilis Triantis; Georgia Plakoutsi; Filip Braet; Karin Vanderkerken; Eddie Wisse

    2000-01-01

    @@ INTRODUCTION Natural killer (NK) cells are functionally defined by their ability to kill certain tumor cells and virusinfected cells without prior sensitization[1]. NK cells comprise about 10% to 15% of lymphocytes in the peripheral blood and most of these cells in human and rat have the morphology of large granular lymphocytes ( LGL )[2]. However, recent studies have demonstrated that small agranular lymphocytes, lacking CD3 expression, have cytolytic activity comparable to NK cells[3].

  4. Epicatechin stimulates mitochondrial activity and selectively sensitizes cancer cells to radiation.

    Directory of Open Access Journals (Sweden)

    Hosam A Elbaz

    Full Text Available Radiotherapy is the treatment of choice for solid tumors including pancreatic cancer, but the effectiveness of treatment is limited by radiation resistance. Resistance to chemotherapy or radiotherapy is associated with reduced mitochondrial respiration and drugs that stimulate mitochondrial respiration may decrease radiation resistance. The objectives of this study were to evaluate the potential of (--epicatechin to stimulate mitochondrial respiration in cancer cells and to selectively sensitize cancer cells to radiation. We investigated the natural compound (--epicatechin for effects on mitochondrial respiration and radiation resistance of pancreatic and glioblastoma cancer cells using a Clark type oxygen electrode, clonogenic survival assays, and Western blot analyses. (--Epicatechin stimulated mitochondrial respiration and oxygen consumption in Panc-1 cells. Human normal fibroblasts were not affected. (--Epicatechin sensitized Panc-1, U87, and MIA PaCa-2 cells with an average radiation enhancement factor (REF of 1.7, 1.5, and 1.2, respectively. (--Epicatechin did not sensitize normal fibroblast cells to ionizing radiation with a REF of 0.9, suggesting cancer cell selectivity. (--Epicatechin enhanced Chk2 phosphorylation and p21 induction when combined with radiation in cancer, but not normal, cells. Taken together, (--epicatechin radiosensitized cancer cells, but not normal cells, and may be a promising candidate for pancreatic cancer treatment when combined with radiation.

  5. Association Between White Blood Cell Count Following Radiation Therapy With Radiation Pneumonitis in Non-Small Cell Lung Cancer

    International Nuclear Information System (INIS)

    Purpose: Radiation pneumonitis (RP) is an inflammatory response to radiation therapy (RT). We assessed the association between RP and white blood cell (WBC) count, an established metric of systemic inflammation, after RT for non-small cell lung cancer. Methods and Materials: We retrospectively analyzed 366 patients with non-small cell lung cancer who received ≥60 Gy as definitive therapy. The primary endpoint was whether WBC count after RT (defined as 2 weeks through 3 months after RT completion) was associated with grade ≥3 or grade ≥2 RP. Median lung volume receiving ≥20 Gy (V20) was 31%, and post-RT WBC counts ranged from 1.7 to 21.2 × 103 WBCs/μL. Odds ratios (ORs) associating clinical variables and post-RT WBC counts with RP were calculated via logistic regression. A recursive-partitioning algorithm was used to define optimal post-RT WBC count cut points. Results: Post-RT WBC counts were significantly higher in patients with grade ≥3 RP than without (P3/μL for grade ≥3 and ≥2 RP, respectively. Univariate analysis revealed significant associations between post-RT WBC count and grade ≥3 (n=46, OR=2.6, 95% confidence interval [CI] 1.4‒4.9, P=.003) and grade ≥2 RP (n=164, OR=2.0, 95% CI 1.2‒3.4, P=.01). This association held in a stepwise multivariate regression. Of note, V20 was found to be significantly associated with grade ≥2 RP (OR=2.2, 95% CI 1.2‒3.4, P=.01) and trended toward significance for grade ≥3 RP (OR=1.9, 95% CI 1.0-3.5, P=.06). Conclusions: Post-RT WBC counts were significantly and independently associated with RP and have potential utility as a diagnostic or predictive marker for this toxicity

  6. The effect of X-ray and heavy ions radiations on chemotherapy refractory tumor cells

    Directory of Open Access Journals (Sweden)

    Zhan eYu

    2016-03-01

    Full Text Available Purpose: To link both numeric and structural chromosomal aberrations to the effectiveness of radiotherapy in chemotherapy refractory tumor cells.Materials and methods: Neuroblastoma (LAN-1 and 79HF6 glioblastoma cells derived from patients and their chemoresistant sublines were artificially cultured as neurospheres and irradiated by x-rays and heavy ions sources. All the cell lines were irradiated by Carbon-SIS with LET of 100 keV/µm. 79HF6 cells were also irradiated by Carbon-UNILAC with LET of 168 keV/µm, while LAN-1 cells were irradiated by Nickel ions with LET of 174 keV/µm. The effect of radiation on the survival and proliferation of cells was addressed by standards clonogenic assays. In order to analyze cell karyotype standard giemsa-staining, multicolor fluorescence in situ hybridization technique and multicolor banding technique were applied.Results: Relative biological effectiveness (RBE values of heavy ions beam relative to X-rays at the D10-values were found between 2.3-2.6 with Carbon-SIS and Nickel for LAN-1, while that were 2.5-3.4 with Carbon-SIS and Carbon-UNILAC for 79HF6 cells. Chemorefractory LAN-1RETO cells were found more radioresistant than untreated LAN-1WT cells. 79HF6RETO glioblastoma cells were found more radiosensitive than cytostatic sensitive cells 79HF6WT. Sphere formation assay showed LAN-1RETO cells were able to form spheres in serum-free culture whereas 79HF6 cells could not. Most of 79HF6WT cells revealed to content 71-90 chromosomes while 79HF6RETO revealed a numeric of 52-83 chromosomes. The majority of LAN-1WT cells revealed a number of 40-44 chromosomes. mFISH analysis showed some stable aberrations especially on chromosome 10 with as judged by the impossibility to label this region with specific probes. This was corroborated using mBAND analysis.Conclusions: Heavy ion irradiation were more effective than X-ray in both cytostatic naive cancer and chemoresistant cell lines. LAN-1RETO chemoresistant

  7. The impact of cell phone radiation on health

    International Nuclear Information System (INIS)

    Constant exposure to radio frequency signals from mobile phones and their base stations could adversely affect on human health. As a consequence, as a result of this impact it is appeared frequent headaches, loss of memory and concentration, tension in the eardrum and sudden bouts of fatigue, childhood leukemia, brain tumors, eye cataracts, cardiovascular diseases, disorders of the nervous system. Some people suffer from hyperelectrosensitivity. It should be noted that the analog phones much more harmful to human health than digital ones. Radio frequency of electromagnetic fields which is used by a modern cellular communications is in the range from 450 MHz to 1.9 GHz. Such fields unlike to ionizing radiation can not cause secondary radioactivity in the body. The cell phone is a device having a potential danger to health, so it is advisable wherever possible to protect yourselves from its use, or at least to minimize its use

  8. Human T-Cell Clones from Autoimmune Thyroid Glands: Specific Recognition of Autologous Thyroid Cells

    Science.gov (United States)

    Londei, Marco; Bottazzo, G. Franco; Feldmann, Marc

    1985-04-01

    The thyroid glands of patients with autoimmune diseases such as Graves' disease and certain forms of goiter contain infiltrating activated T lymphocytes and, unlike cells of normal glands, the epithelial follicular cells strongly express histocompatability antigens of the HLA-DR type. In a study of such autoimmune disorders, the infiltrating T cells from the thyroid glands of two patients with Graves' disease were cloned in mitogen-free interleukin-2 (T-cell growth factor). The clones were expanded and their specificity was tested. Three types of clones were found. One group, of T4 phenotype, specifically recognized autologous thyroid cells. Another, also of T4 phenotype, recognized autologous thyroid or blood cells and thus responded positively in the autologous mixed lymphocyte reaction. Other clones derived from cells that were activated in vivo were of no known specificity. These clones provide a model of a human autoimmune disease and their analysis should clarify mechanisms of pathogenesis and provide clues to abrogating these undesirable immune responses.

  9. Energy-Specific Solar Radiation Data from Msg: the HELIOSAT-3 Project

    Science.gov (United States)

    Schroedter-Homscheidt, M.

    2006-08-01

    Solar energy technologies such as photovoltaics, solar thermal power plants, passive solar heating/cooling systems and day lighting in buildings are expected to continue their very rapid growth. In this context the availability of reliable solar radiation data is of high economic value both for planning and operating these systems. HELIOSAT-3 aims the quantification of surface solar irradiance in cloud free and cloudy situations and additional energy-specific parameters as direct normal and diffuse irradiance over Europe and Africa using the enhanced capabilities of MSG. Emphasis is laid on clouds, water vapor, aerosols and ozone and their influence on surface solar irradiance. Several projects as e.g. the HELIOSAT-3 and PVSAT-2 European Commission FP5 and the ENVISOLAR (ESA Earth Observation Market Development Program) projects made profit from the data access and additional MSG product information obtained through the RAO program. The paper focuses on results obtained during the RAO project based on funding in HELIOSAT-3, PVSAT-2 and ENVISOLAR projects.

  10. Radiation damage and repair in cells and cell components. Progress report, November 1, 1977--October 31, 1978. [Uv and x radiation, bacteriophages

    Energy Technology Data Exchange (ETDEWEB)

    Fluke, D.J.; Pollard, E.C.

    1978-01-01

    Progress is reported on the following research projects: coordinate induction of mutagenesis, radioresistance, and inhibition of post-radiation DNA degradation; radioinduced filamentation; action spectrum for induction of K12 lambda phage; effects of uv radiation on cells in the frozen state; dependence of mutagenesis on wavelength of uv; and w-reactivation of x-irradiated phage lambda. (HLW)

  11. Mitochondria-targeted superoxide dismutase (SOD2) regulates radiation resistance and radiation stress response in HeLa cells

    International Nuclear Information System (INIS)

    Reactive oxygen species (ROS) act as a mediator of ionizing radiation-induced cellular damage. Previous studies have indicated that MnSOD (SOD2) plays a critical role in protection against ionizing radiation in mammalian cells. In this study, we constructed two types of stable HeLa cell lines overexpressing SOD2, HeLa S3/SOD2 and T-REx HeLa/SOD2, to elucidate the mechanisms underlying the protection against radiation by SOD2. SOD2 overexpression in mitochondria enhanced the survival of HeLa S3 and T-REx HeLa cells following γ-irradiation. The levels of γH2AX significantly decreased in HeLa S3/SOD2 and T-REx HeLa/SOD2 cells compared with those in the control cells. MitoSoxTM Red assays showed that both lines of SOD2-expressing cells showed suppression of the superoxide generation in mitochondria. Furthermore, flow cytometry with a fluorescent probe (2',7'-dichlorofluorescein) revealed that the cellular levels of ROS increased in HeLa S3 cells during post-irradiation incubation, but the increase was markedly attenuated in HeLa S3/SOD2 cells. DNA microarray analysis revealed that, of 47,000 probe sets analyzed, 117 and 166 probes showed more than 2-fold changes after 5.5 Gy of γ-irradiation in control and HeLa S3/SOD2 cells, respectively. Pathway analysis revealed different expression profiles in irradiated control cells and irradiated SOD2-overexpressing cells. These results indicate that SOD2 protects HeLa cells against cellular effects of γ-rays through suppressing oxidative stress in irradiated cells caused by ROS generated in the mitochondria and through regulating the expression of genes which play a critical role in protection against ionizing radiation. (author)

  12. Cell Type-Specific Modulation of Respiratory Chain Supercomplex Organization.

    Science.gov (United States)

    Sun, Dayan; Li, Bin; Qiu, Ruyi; Fang, Hezhi; Lyu, Jianxin

    2016-01-01

    Respiratory chain complexes are organized into large supercomplexes among which supercomplex In + IIIn + IVn is the only one that can directly transfer electrons from NADH to oxygen. Recently, it was reported that the formation of supercomplex In + IIIn + IVn in mice largely depends on their genetic background. However, in this study, we showed that the composition of supercomplex In + IIIn + IVn is well conserved in various mouse and human cell lines. Strikingly, we found that a minimal supercomplex In + IIIn, termed "lowest supercomplex" (LSC) in this study because of its migration at the lowest position close to complex V dimers in blue native polyacrylamide gel electrophoresis, was associated with complex IV to form a supercomplex In + IIIn + IVn in some, but not all of the human and mouse cells. In addition, we observed that the 3697G>A mutation in mitochondrial-encoded NADH dehydrogenase 1 (ND1) in one patient with Leigh's disease specifically affected the assembly of supercomplex In + IIIn + IVn containing LSC, leading to decreased cellular respiration and ATP generation. In conclusion, we showed the existence of LSC In + IIIn + IVn and impairment of this supercomplex causes disease. PMID:27338358

  13. Thrombin-specific inactivation of endothelial cell derived plasminogen activator

    International Nuclear Information System (INIS)

    Although thrombin (T) has diverse functions in the overall hemostatic mechanism, relatively little is known about its direct effect on components of the fibrinolytic enzyme system. The authors have investigated the interaction of T with plasminogen activators (PA) derived from bovine aortic endothelial cells (EC) in culture (2-5th passage, preconfluent monolayers). Varying concentrations of purified bovine or human thrombin were added to EC-conditioned media (CM). CM + T mixtures were assayed at various times for PA activity using purified plasminogen and a sensitive 125I-fibrinogenolytic or caseinolytic assay. T (5 nM), but not plasmin or trypsin at equivalent concentrations, resulted in a time-dependent inhibition of the PA activity in CM. T had no effect on the PA activity of urokinase, streptokinase or preformed plasmin. The ability of T to inactivate the EC-derived PA was abolished by prior treatment of T with active site-directed reagents. SDS-PAGE and zymography with copolymerized fibrinogen and plasminogen revealed further specificity in that only one of the multiple-molecular weight forms of PA present in EC-CM was inactivated by T. The authors conclude that in a highly specific fashion, T inactivates the predominant PA present in EC-CM by limited proteolysis. Thus, another potentially important function of T is suggested which may have particular significance in the temporal regulation of coagulation and fibrinolysis at the blood-endothelium interface

  14. Studies on the mechanism of the self restriction of T cell responses in radiation chimeras

    International Nuclear Information System (INIS)

    Recent experiments with murine radiation chimeras have shown that F1 T cells that mature in an H-2 homozygous thymus, as is the case in [F1 → Parent 1] chimeras, are restricted to recognizing foreign antigen in the context of Parent 1 H-2 antigens. Conflicting results on the stringency of self H-2 restriction of T cells from normal mice have suggested that the thymic restriction in chimeras may be due to active suppression of parent 2-restricted T cell clones. We have therefore conducted 3 sets of experiments to test for suppression of maturing T cells that could mediate thymic tutoring of H-2-restriction specificity in chimeras. In 2 sets of experiments, we found no evidence that suppressor cells could be exported from 1 thymus and act either intrathymically on thymocytes in a 2nd thymus or extrathymically on recent thymic emigrants. We believe current data support a role for the thymus in positive as well as negative selection of maturing thymocytes on the basis of self recognition, in the absence of any suppression. Our results do not support the concept that suppression is responsible for the difference in the degree of self preference in the T cells of chimeric mice relative to cell populations obtained from neonatally tolerant mice or from normal mice after acute negative selection

  15. Lineage-specific interface proteins match up the cell cycle and differentiation in embryo stem cells

    DEFF Research Database (Denmark)

    Re, Angela; Workman, Christopher; Waldron, Levi;

    2014-01-01

    The shortage of molecular information on cell cycle changes along embryonic stem cell (ESC) differentiation prompts an in silico approach, which may provide a novel way to identify candidate genes or mechanisms acting in coordinating the two programs. We analyzed germ layer specific gene expression...... changes during the cell cycle and ESC differentiation by combining four human cell cycle transcriptome profiles with thirteen in vitro human ESC differentiation studies. To detect cross-talk mechanisms we then integrated the transcriptome data that displayed differential regulation with protein...... interaction data. A new class of non-transcriptionally regulated genes was identified, encoding proteins which interact systematically with proteins corresponding to genes regulated during the cell cycle or cell differentiation, and which therefore can be seen as interface proteins coordinating the two...

  16. Effect of ionizing radiation on invasiveness of pulmonary adenocarcinoma cells A549 and its mechanism

    International Nuclear Information System (INIS)

    Objective: To investigate the effect of ionizing radiation on the invasion of the pulmonary adenocarcinoma cell line A549. Methods: The invasiveness of A549 cells irradiated with 2 and 4 Gy doses of γ-rays was detected by using transwell invasion assay. The expression levels of matrix metalloproteinase (MMP)-2 mRNA and protein and phosphorylated signal transducers and activators of transcription 3 (STAT3) protein were detected by reverse transcription PCR and Western blot. Results: After irradiation with 2 or 4 Gy, the invasiveness of A549 cells increased by 200.0% (F=111.7, P<0.01) and 390.9% (F=593.7, P<0.01), respectively, compared with that in untreated A549 cells.Furthermore, the transcription and protein expression of MMP-2 24 h after irradiation and the phosphorylation of STAT3 12 h after irradiation were promoted. The irradiation-induced elevation of MMP-2 protein expression was suppressed using STAT3 phosphorylation specific inhibitor (AG490). Moreover, compared with 4 Gy of irradiation alone, treatment with 4 Gy of irradiation plus AG490 decreased the number of invasive cells by 76.1% (F=555.9, P<0.01), and the number of invasive cells in 4 Gy of irradiation plus AG490 group made up only 117.8% of that in untreated group (F=3.6, P>0.05). Conclusions: Ionizing radiation could activate STAT3, which triggers the transcription of MMP-2, and then promote the invasiveness of A549 cells. (authors)

  17. The specificity of albumin denaturation on physiological preparations under thermal and gamma-radiation effects (actions)

    International Nuclear Information System (INIS)

    Comparative investigation is performed of the alteration in thin structure of absorption spectra of albumin solutions under thermal and radiation effect resulting in protein denaturation. Gamma radiation effect of 57Co on the preparations of bull and man serum albumins was studied as well as a number of serum preparations. Analysis of the results obtained permits to conclude that different qualitative and quantitative mechanisms of denaturation alterations under the temperature and gamma radiation effects on albumin solutions takes place

  18. Molecular Cloning and Functional Analysis of ESGP, an Embryonic Stem Cell and Germ Cell Specific Protein

    Institute of Scientific and Technical Information of China (English)

    Yan-Mei CHEN; Zhong-Wei DU; Zhen YAO

    2005-01-01

    Several putative Oct-4 downstream genes from mouse embryonic stem (ES) cells have been identified using the suppression-subtractive hybridization method. In this study, one of the novel genes encoding an ES cell and germ cell specific protein (ESGP) was cloned by rapid amplification of cDNA ends.ESGP contains 801 bp encoding an 84 amino acid small protein and has no significant homology to any known genes. There is a signal peptide at the N-terminal of ESGP protein as predicted by SeqWeb (GCG)(SeqWeb version 2.0.2, http://gcg.biosino.org:8080/). The result of immunofluorescence assay suggested that ESGP might encode a secretory protein. The expression pattern of ESGP is consistent with the expression of Oct-4 during embryonic development. ESGP protein was detected in fertilized oocyte, from 3.5 day postcoital (dpc) blastocyst to 17.5 dpc embryo, and was only detected in testis and ovary tissues in adult. In vitro, ESGP was only expressed in pluripotent cell lines, such as embryonic stem cells, embryonic carcinoma cells and embryonic germ cells, but not in their differentiated progenies. Despite its specific expression,forced expression of ESGP is not indispensable for the effect of Oct-4 on ES cell self-renewal, and does not affect the differentiation to three germ layers.

  19. An Evaluation of Dose Equivalence between Synchrotron Microbeam Radiation Therapy and Conventional Broadbeam Radiation Using Clonogenic and Cell Impedance Assays

    OpenAIRE

    Mohammad Johari Ibahim; Crosbie, Jeffrey C.; Yuqing Yang; Marina Zaitseva; Andrew W Stevenson; Rogers, Peter A. W.; Premila Paiva

    2014-01-01

    BACKGROUND: High-dose synchrotron microbeam radiation therapy (MRT) has shown the potential to deliver improved outcomes over conventional broadbeam (BB) radiation therapy. To implement synchrotron MRT clinically for cancer treatment, it is necessary to undertake dose equivalence studies to identify MRT doses that give similar outcomes to BB treatments. AIM: To develop an in vitro approach to determine biological dose equivalence between MRT and BB using two different cell-based assays. METHO...

  20. Chimeric antigen receptor (CAR-specific monoclonal antibody to detect CD19-specific T cells in clinical trials.

    Directory of Open Access Journals (Sweden)

    Bipulendu Jena

    Full Text Available Clinical trials targeting CD19 on B-cell malignancies are underway with encouraging anti-tumor responses. Most infuse T cells genetically modified to express a chimeric antigen receptor (CAR with specificity derived from the scFv region of a CD19-specific mouse monoclonal antibody (mAb, clone FMC63. We describe a novel anti-idiotype monoclonal antibody (mAb to detect CD19-specific CAR(+ T cells before and after their adoptive transfer. This mouse mAb was generated by immunizing with a cellular vaccine expressing the antigen-recognition domain of FMC63. The specificity of the mAb (clone no. 136.20.1 was confined to the scFv region of the CAR as validated by inhibiting CAR-dependent lysis of CD19(+ tumor targets. This clone can be used to detect CD19-specific CAR(+ T cells in peripheral blood mononuclear cells at a sensitivity of 1∶1,000. In clinical settings the mAb is used to inform on the immunophenotype and persistence of administered CD19-specific T cells. Thus, our CD19-specific CAR mAb (clone no. 136.20.1 will be useful to investigators implementing CD19-specific CAR(+ T cells to treat B-lineage malignancies. The methodology described to develop a CAR-specific anti-idiotypic mAb could be extended to other gene therapy trials targeting different tumor associated antigens in the context of CAR-based adoptive T-cell therapy.

  1. Radiation Survival in Synchronous and Asynchronous Chinese Hamster Cells In Vitro

    International Nuclear Information System (INIS)

    Synchronized mammalian cells enable radiation responses to be examined as a function of the position of the cell within its generation cycle. However, synchrony techniques are limited by the random distribution of generation rates in cell populations and, because of the techniques employed, stages such as G2 and mitosis are difficult to examine. Superposing on the mitotic selection technique high-specific- activity tritiated thymidine to inactivate resistant S cells enables the average sensitivity of G2 and mitotic cells to be established. The changes in sensitivity during the cell cycle for Chinese hamster cells are considerable, at least as great as the effect of the presence or absence of oxygen. G2 and mitosis are the most sensitive cells, followed by G1, early S and finally late S cells as the most resistant. With this data the response of an asynchronous population can be estimated and compared with experimental data. Calculation and experiment agree well. The selection + tritiated thymidine technique is still limited in resolution to a one-hour period. Experiments varying the interval between irradiation and selection indicate that there is, very probably, a brief phase more sensitive than the average in the selected mitotic population which should be examined further. Experiments with Janus (fission) neutrons indicate that the changes in response during the cell cycle are smaller than for X-rays and the shapes of the survival curves are different. The RBE of these neutrons is shown to vary with both dose level and position in the cell cycle. (author)

  2. Effects of gamma radiation on Sporothrix schenckii yeast cells

    International Nuclear Information System (INIS)

    Sporotrichosis is a subacute or chronic infection caused by the fungus Sporothrix schenckii. Zoonotic transmission can occur after scratches or bites of animals, mainly cats, rodents, and armadillos. Up to the moment, no approved vaccine was reported for S. schenckii or to any important pathogenic fungi infection in humans, indicating the need to expand the research in this field and to explore new alternatives. The aim of this study was to evaluate the effects of gamma radiation in the viability, metabolic activity and reproductive ability of S. schenckii yeast cells for further studies on the development of a vaccine for immunization of cats and dogs. The culture of S. schenckii, in solid medium, was irradiated at doses ranging from 1.0 to 9.0 kGy. After each dose the reproductive capacity, viability and protein synthesis were estimated. The results showed that a reduction of 6 log10 cycles in the number of colonies was achieved at 6.0 kGy and after 8.0 kGy no colonies could be recovered. The viability analysis indicated that yeast cells remained viable up to 9.0 kGy. The results of protein synthesis analysis showed that the yeast cells, irradiated up to 9.0 kGy, were able to synthesize proteins. Our preliminary results indicated that for the yeast cells of S. schenckii, it is possible to find an absorbed dose in which the pathogen loses its reproductive ability, while retaining its viability, a necessary condition for the development of a radioattenuated yeast vaccine. (author)

  3. Effects of gamma radiation on Sporothrix schenckii yeast cells

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda, Camila M. de Sousa; Martins, Estefania Mara Nascimento; Andrade, Antero S.R. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)], e-mail: cmsl@cdtn.br, e-mail: estefaniabio@yahoo.com.br, e-mail: antero@cdtn.br; Resende, Maria Aparecida de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Microbiologia], e-mail: maressend@mono.icb.ufmg.br

    2009-07-01

    Sporotrichosis is a subacute or chronic infection caused by the fungus Sporothrix schenckii. Zoonotic transmission can occur after scratches or bites of animals, mainly cats, rodents, and armadillos. Up to the moment, no approved vaccine was reported for S. schenckii or to any important pathogenic fungi infection in humans, indicating the need to expand the research in this field and to explore new alternatives. The aim of this study was to evaluate the effects of gamma radiation in the viability, metabolic activity and reproductive ability of S. schenckii yeast cells for further studies on the development of a vaccine for immunization of cats and dogs. The culture of S. schenckii, in solid medium, was irradiated at doses ranging from 1.0 to 9.0 kGy. After each dose the reproductive capacity, viability and protein synthesis were estimated. The results showed that a reduction of 6 log{sub 10} cycles in the number of colonies was achieved at 6.0 kGy and after 8.0 kGy no colonies could be recovered. The viability analysis indicated that yeast cells remained viable up to 9.0 kGy. The results of protein synthesis analysis showed that the yeast cells, irradiated up to 9.0 kGy, were able to synthesize proteins. Our preliminary results indicated that for the yeast cells of S. schenckii, it is possible to find an absorbed dose in which the pathogen loses its reproductive ability, while retaining its viability, a necessary condition for the development of a radioattenuated yeast vaccine. (author)

  4. Stereotactic body radiation therapy versus conventional radiation therapy in patients with early stage non-small cell lung cancer

    DEFF Research Database (Denmark)

    Jeppesen, Stefan Starup; Schytte, Tine; Jensen, Henrik R;

    2013-01-01

    Abstract Introduction. Stereotactic body radiation therapy (SBRT) for early stage non-small cell lung cancer (NSCLC) is now an accepted and patient friendly treatment, but still controversy exists about its comparability to conventional radiation therapy (RT). The purpose of this single...... and SBRT predicted improved prognosis. However, staging procedure, confirmation procedure of recurrence and technical improvements of radiation treatment is likely to influence outcomes. However, SBRT seems to be as efficient as conventional RT and is a more convenient treatment for the patients....

  5. Induction of chromosome aberrations in two lines of cultured cells using different types of radiation

    International Nuclear Information System (INIS)

    The induction of chromosome aberrations has been investigated in two lines of cultured cells for different types of radiation. The obtained results are compared with information on induction of cell reproductive death and malignant transformation. (Auth.)

  6. The different radiation response and radiation-induced bystander effects in colorectal carcinoma cells differing in p53 status

    Energy Technology Data Exchange (ETDEWEB)

    Widel, Maria, E-mail: maria.widel@polsl.pl [Biosystems Group, Institute of Automatic Control, Silesian University of Technology, 16 Akademicka Street, 44-100 Gliwice (Poland); Lalik, Anna; Krzywon, Aleksandra [Biosystems Group, Institute of Automatic Control, Silesian University of Technology, 16 Akademicka Street, 44-100 Gliwice (Poland); Poleszczuk, Jan [College of Inter-faculty Individual Studies in Mathematics and Natural Sciences, University of Warsaw, 93 Zwirki i Wigury Street, 02-089 Warsaw (Poland); Department of Integrated Mathematical Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida (United States); Fujarewicz, Krzysztof; Rzeszowska-Wolny, Joanna [Biosystems Group, Institute of Automatic Control, Silesian University of Technology, 16 Akademicka Street, 44-100 Gliwice (Poland)

    2015-08-15

    Highlights: • We tested radiation response and bystander effect on HCT116p53+/+ and p53−/− cells. • The p53+/+ cells developed premature senescence in exposed and bystander neighbors. • Directly exposed and bystander p53−/− cells died profoundly through apoptosis. • Interleukins 6 and 8 were differently generated by both cell lines. • NFκB path was activated mainly in p53+/+ hit cells, in p53 −/− in bystanders only. - Abstract: Radiation-induced bystander effect, appearing as different biological changes in cells that are not directly exposed to ionizing radiation but are under the influence of molecular signals secreted by irradiated neighbors, have recently attracted considerable interest due to their possible implication for radiotherapy. However, various cells present diverse radiosensitivity and bystander responses that depend, inter alia, on genetic status including TP53, the gene controlling the cell cycle, DNA repair and apoptosis. Here we compared the ionizing radiation and bystander responses of human colorectal carcinoma HCT116 cells with wild type or knockout TP53 using a transwell co-culture system. The viability of exposed to X-rays (0–8 Gy) and bystander cells of both lines showed a roughly comparable decline with increasing dose. The frequency of micronuclei was also comparable at lower doses but at higher increased considerably, especially in bystander TP53-/- cells. Moreover, the TP53-/- cells showed a significantly elevated frequency of apoptosis, while TP53+/+ counterparts expressed high level of senescence. The cross-matched experiments where irradiated cells of one line were co-cultured with non-irradiated cells of opposite line show that both cell lines were also able to induce bystander effects in their counterparts, however different endpoints revealed with different strength. Potential mediators of bystander effects, IL-6 and IL-8, were also generated differently in both lines. The knockout cells secreted IL-6 at

  7. The different radiation response and radiation-induced bystander effects in colorectal carcinoma cells differing in p53 status

    International Nuclear Information System (INIS)

    Highlights: • We tested radiation response and bystander effect on HCT116p53+/+ and p53−/− cells. • The p53+/+ cells developed premature senescence in exposed and bystander neighbors. • Directly exposed and bystander p53−/− cells died profoundly through apoptosis. • Interleukins 6 and 8 were differently generated by both cell lines. • NFκB path was activated mainly in p53+/+ hit cells, in p53 −/− in bystanders only. - Abstract: Radiation-induced bystander effect, appearing as different biological changes in cells that are not directly exposed to ionizing radiation but are under the influence of molecular signals secreted by irradiated neighbors, have recently attracted considerable interest due to their possible implication for radiotherapy. However, various cells present diverse radiosensitivity and bystander responses that depend, inter alia, on genetic status including TP53, the gene controlling the cell cycle, DNA repair and apoptosis. Here we compared the ionizing radiation and bystander responses of human colorectal carcinoma HCT116 cells with wild type or knockout TP53 using a transwell co-culture system. The viability of exposed to X-rays (0–8 Gy) and bystander cells of both lines showed a roughly comparable decline with increasing dose. The frequency of micronuclei was also comparable at lower doses but at higher increased considerably, especially in bystander TP53-/- cells. Moreover, the TP53-/- cells showed a significantly elevated frequency of apoptosis, while TP53+/+ counterparts expressed high level of senescence. The cross-matched experiments where irradiated cells of one line were co-cultured with non-irradiated cells of opposite line show that both cell lines were also able to induce bystander effects in their counterparts, however different endpoints revealed with different strength. Potential mediators of bystander effects, IL-6 and IL-8, were also generated differently in both lines. The knockout cells secreted IL-6 at

  8. Low-Dose Radiation Induces Cell Proliferation in Human Embryonic Lung Fibroblasts but not in Lung Cancer Cells

    Directory of Open Access Journals (Sweden)

    Xinyue Liang

    2016-01-01

    Full Text Available Hormesis and adaptive responses are 2 important biological effects of low-dose ionizing radiation (LDR. In normal tissue, LDR induces hormesis as evinced by increased cell proliferation; however, whether LDR also increases tumor cell proliferation needs to be investigated. In this study, cell proliferation was assayed by total cell numbers and the Cell Counting Kit 8 assay. Mitogen-activated protein kinases (MAPK/extracellular signal-regulated kinase (ERK and phosphatidylinositol 3′ -kinase(PI3K-Akt (PI3K/AKT phosphorylation were determined by Western blot analysis. Human embryonic lung fibroblast 2BS and lung cancer NCI-H446 cell lines were irradiated with LDR at different doses (20-100 mGy. In response to 20 to 75 mGy X-rays, cell proliferation was significantly increased in 2BS but not in NCI-H446 cells. In 2BS cells, LDR at 20 to 75 mGy also stimulated phosphorylation of MAPK/ERK pathway proteins including ERK, MEK, and Raf and of the PI3K/AKT pathway protein AKT. To test whether ERK1/2 and AKT pathway activation was involved in the stimulation of cell proliferation in 2BS cells, the MAPK/ERK and PI3K/AKT pathways were inhibited using their specific inhibitors, U0126 and LY294002. U0126 decreased the phosphorylation of ERK1/2, and LY294002 decreased the phosphorylation of AKT; each could significantly inhibit LDR-induced 2BS cell proliferation. However, LDR did not stimulate these kinases, and kinase inhibitors also did not affect cell proliferation in the NCI-H446 cells. These results suggest that LDR stimulates cell proliferation via the activation of both MAPK/ERK and PI3K/AKT signaling pathways in 2BS but not in NCI-H446 cells. This finding implies the potential for applying LDR to protect normal tissues from radiotherapy without diminishing the efficacy of tumor therapy.

  9. Tumour microenvironment and radiation response in sarcomas originating from tumourigenic human mesenchymal stem cells

    DEFF Research Database (Denmark)

    D'Andrea, Filippo Peder; Safwat, Akmal Ahmed; Burns, Jorge S.;

    2012-01-01

    Background: Resistance to radiation therapy remains a serious impediment to cancer therapy. We previously reported heterogeneity for clonogenic survival when testing in vitro radiation resistance among single cell derived clones from a human mesenchymal cancer stem cell model (hMSC). Here we aimed...

  10. Construction of cell type-specific logic models of signaling networks using CellNOpt.

    Science.gov (United States)

    Morris, Melody K; Melas, Ioannis; Saez-Rodriguez, Julio

    2013-01-01

    Mathematical models are useful tools for understanding protein signaling networks because they provide an integrated view of pharmacological and toxicological processes at the molecular level. Here we describe an approach previously introduced based on logic modeling to generate cell-specific, mechanistic and predictive models of signal transduction. Models are derived from a network encoding prior knowledge that is trained to signaling data, and can be either binary (based on Boolean logic) or quantitative (using a recently developed formalism, constrained fuzzy logic). The approach is implemented in the freely available tool CellNetOptimizer (CellNOpt). We explain the process CellNOpt uses to train a prior knowledge network to data and illustrate its application with a toy example as well as a realistic case describing signaling networks in the HepG2 liver cancer cell line.

  11. Resistance of colorectal cancer cells to radiation and 5-FU is associated with MELK expression

    International Nuclear Information System (INIS)

    Highlights: → MELK expression significantly increased when the cells are exposed to radiation or 5-FU. → Suppression of MELK caused cell cycle changes and decrease in proliferation. → Radiation or 5-FU treatment after MELK suppression by siRNA induced growth inhibition. -- Abstract: It was reported that the local recurrence would be caused by cancer stem cells acquiring chemo- and radio-resistance. Recently, one of the potential therapeutic targets for colorectal and other cancers has been identified, which is maternal embryonic leucine zipper kinase (MELK). MELK is known as an embryonic and neural stem cell marker, and associated with the cell survival, cell proliferation, and apoptosis. In this study, SNU-503, which is a rectal cancer cell line, was treated with radiation or 5-fluorouracil (5-FU), and elevation of the MELK expression level was observed. Furthermore, the cell line was pre-treated with small interfering RNA (siRNA) against MELK mRNA before treatment of radiation or 5-FU and its effects on cell cycle and proliferation were observed. We demonstrated that knockdown of MELK reduced the proliferation of cells with radiation or 5-FU treatment. In addition, MELK suppression caused changes in cell cycle. In conclusion, MELK could be associated with increased resistance of colorectal cancer cells against radiation and 5-FU.

  12. Resistance of colorectal cancer cells to radiation and 5-FU is associated with MELK expression

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seungho [Laboratory of Cell Biology, Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Ku, Ja-Lok, E-mail: kujalok@snu.ac.kr [Laboratory of Cell Biology, Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of)

    2011-08-26

    Highlights: {yields} MELK expression significantly increased when the cells are exposed to radiation or 5-FU. {yields} Suppression of MELK caused cell cycle changes and decrease in proliferation. {yields} Radiation or 5-FU treatment after MELK suppression by siRNA induced growth inhibition. -- Abstract: It was reported that the local recurrence would be caused by cancer stem cells acquiring chemo- and radio-resistance. Recently, one of the potential therapeutic targets for colorectal and other cancers has been identified, which is maternal embryonic leucine zipper kinase (MELK). MELK is known as an embryonic and neural stem cell marker, and associated with the cell survival, cell proliferation, and apoptosis. In this study, SNU-503, which is a rectal cancer cell line, was treated with radiation or 5-fluorouracil (5-FU), and elevation of the MELK expression level was observed. Furthermore, the cell line was pre-treated with small interfering RNA (siRNA) against MELK mRNA before treatment of radiation or 5-FU and its effects on cell cycle and proliferation were observed. We demonstrated that knockdown of MELK reduced the proliferation of cells with radiation or 5-FU treatment. In addition, MELK suppression caused changes in cell cycle. In conclusion, MELK could be associated with increased resistance of colorectal cancer cells against radiation and 5-FU.

  13. Impact of tissue-specific stem cells on lineage-specific differentiation: a focus on the musculoskeletal system.

    Science.gov (United States)

    Pizzute, Tyler; Lynch, Kevin; Pei, Ming

    2015-02-01

    Tissue-specific stem cells are found throughout the body and, with proper intervention and environmental cues, these stem cells exercise their capabilities for differentiation into several lineages to form cartilage, bone, muscle, and adipose tissue in vitro and in vivo. Interestingly, it has been widely demonstrated that they do not differentiate with the same efficacy during lineage-specific differentiation studies, as the tissue-specific stem cells are generally more effective when differentiating toward the tissues from which they were derived. This review focuses on four mesodermal lineages for tissue-specific stem cell differentiation: adipogenesis, chondrogenesis, myogenesis, and osteogenesis. It is intended to give insight into current multilineage differentiation and comparative research, highlight and contrast known trends regarding differentiation, and introduce supporting evidence which demonstrates particular tissue-specific stem cells' superiority in lineage-specific differentiation, along with their resident tissue origins and natural roles. In addition, some epigenetic and transcriptomic differences between stem cells which may explain the observed trends are discussed.

  14. Prostate-specific antigen bounce following stereotactic body radiation therapy for prostate cancer

    Directory of Open Access Journals (Sweden)

    Charles C. Vu

    2014-01-01

    Full Text Available Introduction: Prostate-specific antigen (PSA bounce after brachytherapy has been well-documented. This phenomenon has also been identified in patients undergoing stereotactic body radiation therapy (SBRT. While the parameters that predict PSA bounce have been extensively studied in prostate brachytherapy patients, this study is the first to analyze the clinical and pathologic predictors of PSA bounce in prostate SBRT patients. Materials and Methods: Our institution has maintained a prospective database of patients undergoing SBRT for prostate cancer since 2006. Our study population includes patients between May 2006 and November 2011 who have at least 18 months of follow-up. All patients were treated using the CyberKnife treatment system. The prescription dose was 3500-3625cGy in 5 fractions.Results: 120 patients were included in our study. Median PSA follow-up was 24 months (range 18-78 months. 34 (28% patients had a PSA bounce. The median time to PSA bounce was 9 months, and the median bounce size was 0.50ng/mL. On univariate analysis, only younger age (p = .011 was shown to be associated with an increased incidence of PSA bounce. Other patient factors, including race, prostate size, prior treatment by hormones, and family history of prostate cancer, did not predict PSA bounces. None of the tumor characteristics studied, including Gleason score, pre-treatment PSA, T-stage, or risk classification by NCCN guidelines, was associated with increased incidence of PSA bounces. Younger age was the only statistically significant predictor of PSA bounce on multivariate analysis (OR = 0.937, p = 0.009.Conclusion: PSA bounce, which has been reported after prostate brachytherapy, is also seen in a significant percentage of patients after CyberKnife SBRT. Close observation rather than biopsy can be considered for these patients. Younger age was the only factor that predicted PSA bounce.

  15. Effect of specific leaf nitrogen on radiation use efficiency and growth of sunflower

    International Nuclear Information System (INIS)

    Specific leaf nitrogen (SLN, g/m2) is known to affect radiation use efficiency (RUE, g/MJ) in different crops. However, this association and importance have not been well established over a range of different nitrogen regimes for field-grown sunflower (Helianthus annuus L.). An experiment was conducted to investigate different combinations and rates of applied nitrogen on SLN, RUE, and growth of sunflower. A fully irrigated crop was sown on an alluvial-prairie soil (Fluventic Haplustoll) and treated with five combinations of applied nitrogen. Greater nitrogen increased biomass, grain number, and yield, but did not affect harvest index energy-corrected for oil (0.4) or canopy extinction coefficient (0.88). Decreases in biomass accumulation under low nitrogen treatments were associated with reductions in leaf area index (LAI) and light interception. When SLN and RUE were examined together, both were less in the anthesis to physiological maturity period, but relatively stable between bud visible and anthesis. However, the effects of canopy SLN on RUE were confounded by high SLN in the top of the canopy and the crop maintaining SLN by reducing LAI. Measurements of leaf CO2 assimilation and theoretical analyses of RUE supported that RUE was related to SLN. The major effect of nitrogen on early growth of sunflower was mediated by leaf area and the distribution of SLN in the canopy rather than direct effects of canopy SLN on RUE alone. Greater responses of RUE to SLN are more evident later in growth, and may be related to the demand of nitrogen by the grain

  16. Impact of ionizing radiation on human embryonic stem cells

    OpenAIRE

    Luft, Sabine

    2015-01-01

    The radiosensitivity of the early developing human embryo is not well characterized. Radiation protection guidelines in case of an in utero exposure are mainly based on animal experiments and on epidemiological data. The mechanisms behind a radiation response of the embryo especially of high LET radiation is not completely understood. Therefore, there is a need to elucidate the effects of low and high LET ionizing radiation on early embryonic development. To contribute to a better understandi...

  17. Recombinant scorpion insectotoxin AaIT kills specifically insect cells but not human cells

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The nucleotide sequence deduced from the amino acid sequence of the scorpion insectotoxin AaIT was chemically synthesized and was expressed in Escherichia coli. The authenticity of this in vitro expressed peptide was confirmed by N-terminal peptide sequencing. Two groups of bioassays, artificial diet incorporation assay and contact insecticidal effect assay, were carried out separately to verify the toxicity of this recombinant toxin. At the end of a 24 h experimental period, more than 60% of the testing diamondback moth (Plutella xylostella) larvae were killed in both groups with LCs0 value of 18.4 uM and 0.70 μM respectively. Cytotoxicity assay using cultured Sf9 insect cells and MCF-7 human cells demonstrated that the toxin AaIT had specific toxicity against insect cells but not human cells. Only 0.13 μM recombinant toxin was needed to kill 50% of cultured insect cells while as much as 1.3μM toxin had absolutely no effect on human cells. Insect cells produced obvious intrusions from their plasma membrane before broken up. We infer that toxin AaIT bind to a putative sodium channel in these insect cells and open the channel persistently, which would result in Na+ influx and finally cause destruction of insect cells.

  18. The modulation of radiation-induced cell death by genistein in K562 cells:Activation of thymidine kinase 1

    Institute of Scientific and Technical Information of China (English)

    Min Ho JEONG; Young Hee JIN; Eun Young KANG; Wol Soon JO; Hwan Tae PARK; Jae Dong LEE; Yeo Jin YOO; Soo Jin JEONG

    2004-01-01

    Ionizing radiation is one of the most effective tools in cancer therapy. In a previous study, we reported that protein tyrosine kinase (PTK) inhibitors modulate the radiation responses in the human chronic myelogenous leukemia (CML)cell line K562. The receptor tyrosine kinase inhibitor, genistein, delayed radiation-induced cell death, while non-recepter tyrosine kinase inhibitor, herbimycin A (HMA) enhances radiation-induced apoptosis. In this study, we focused on the modulation of radiation-induced cell death by genistein and performed PCR-select suppression subtractive hybridization(SSH) to understand its molecular mechanism. We identified human thymidine kinase 1 (TK1), which is cell cycle regulatory gene and confirmed expression of TK1 mRNA by Northern blot analysis. Expression of TK1 mRNA and TK 1enzymatic activity were parallel in their increase and decrease. TK1 is involved in G1-S phase transition of cell cycle progression. In cell cycle analysis, we showed that radiation induced G2 arrest in K562 cells but it was not able to sustain. However, the addition of genistein to irradiated cells sustained a prolonged G2 arrest up to 120 h. In addition,the expression of cell cycle-related proteins, cyclin A and cyclin B 1, provided the evidences of G1/S progression and G2-arrest, and their relationship with TK1 in cells treated with radiation and genistein. These results suggest that the activation of TK1 may be critical to modulate the radiation-induced cell death and cell cycle progression in irradiated K562 cells.

  19. Combination Effect of Regulatory T-Cell Depletion and Ionizing Radiation in Mouse Models of Lung and Colon Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Son, Cheol-Hun [Dongnam Institute of Radiological and Medical Sciences, Busan (Korea, Republic of); Department of Biochemistry, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Bae, Jae-Ho [Department of Biochemistry, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Shin, Dong-Yeok; Lee, Hong-Rae; Jo, Wol-Soon; Yang, Kwangmo [Dongnam Institute of Radiological and Medical Sciences, Busan (Korea, Republic of); Park, You-Soo, E-mail: biotek01@hanmail.net [Dongnam Institute of Radiological and Medical Sciences, Busan (Korea, Republic of)

    2015-06-01

    Purpose: To investigate the potential of low-dose cyclophosphamide (LD-CTX) and anti-CD25 antibody to prevent activation of regulatory T cells (Tregs) during radiation therapy. Methods and Materials: We used LD-CTX and anti-CD25 monoclonal antibody as a means to inhibit Tregs and improve the therapeutic effect of radiation in a mouse model of lung and colon cancer. Mice were irradiated on the tumor mass of the right leg and treated with LD-CTX and anti-CD25 antibody once per week for 3 weeks. Results: Combined treatment of LD-CTX or anti-CD25 antibody with radiation significantly decreased Tregs in the spleen and tumor compared with control and irradiation only in both lung and colon cancer. Combinatorial treatments resulted in a significant increase in the effector T cells, longer survival rate, and suppressed irradiated and distal nonirradiated tumor growth. Specifically, the combinatorial treatment of LD-CTX with radiation resulted in outstanding regression of local and distant tumors in colon cancer, and almost all mice in this group survived until the end of the study. Conclusions: Our results suggest that Treg depletion strategies may enhance radiation-mediated antitumor immunity and further improve outcomes after radiation therapy.

  20. Combination Effect of Regulatory T-Cell Depletion and Ionizing Radiation in Mouse Models of Lung and Colon Cancer

    International Nuclear Information System (INIS)

    Purpose: To investigate the potential of low-dose cyclophosphamide (LD-CTX) and anti-CD25 antibody to prevent activation of regulatory T cells (Tregs) during radiation therapy. Methods and Materials: We used LD-CTX and anti-CD25 monoclonal antibody as a means to inhibit Tregs and improve the therapeutic effect of radiation in a mouse model of lung and colon cancer. Mice were irradiated on the tumor mass of the right leg and treated with LD-CTX and anti-CD25 antibody once per week for 3 weeks. Results: Combined treatment of LD-CTX or anti-CD25 antibody with radiation significantly decreased Tregs in the spleen and tumor compared with control and irradiation only in both lung and colon cancer. Combinatorial treatments resulted in a significant increase in the effector T cells, longer survival rate, and suppressed irradiated and distal nonirradiated tumor growth. Specifically, the combinatorial treatment of LD-CTX with radiation resulted in outstanding regression of local and distant tumors in colon cancer, and almost all mice in this group survived until the end of the study. Conclusions: Our results suggest that Treg depletion strategies may enhance radiation-mediated antitumor immunity and further improve outcomes after radiation therapy

  1. GATA-3 promotes T-cell specification by repressing B-cell potential in pro-T cells in mice

    NARCIS (Netherlands)

    M.E. García (Marcos); R.G.J. Klein Wolterink (Roel); F. Lemâitre (Fabrice); C. Le Goff (Carine); M. Hasan (Milena); R.W. Hendriks (Rudi); A. Cumano (Ana); J.P. di Santo (James)

    2013-01-01

    textabstractTranscription factors orchestrate T-lineage differentiation in the thymus. One critical checkpoint involves Notch1 signaling that instructs T-cell commitment at the expense of the B-lineage program. While GATA-3 is required for T-cell specification, its mechanism of action is poorly unde

  2. Radiation induced damage to the lipid contents of bacteria and cultured mammalian cells

    International Nuclear Information System (INIS)

    In this study, exponentially growing phase of E. Coli. K12-N167 and cultured mouse leukemic L5178Y were used to study the effect of gamma irradiation on phospholipid contents. Following irradiation, both bacteria and cultured cells were incubated with either 14C or 32P labelled precursors for periods of cell division time. Phospholipid composition and their contents were detected in both the bacteria and cultured cells by using liquid scintillation counting and autoradiography methods. In contrast, as radiation dose increased, the Phospholipid contents were decreased in the both bacteria and cultured cells. It was concluded that the changes of phospholipid contents may result to altered activities of phospholipid pathway enzymes damaged by a radiation dose. The results of this investigation would be helpful in control of induced radiation damages in cell killings in radiation workers and radiation treatment of human cancer in the clinics. (author). 35 refs, 3 figs, 4 tabs

  3. Tissue-specific stem cells: friend or foe?

    Institute of Scientific and Technical Information of China (English)

    Joerg Huelsken

    2009-01-01

    @@ In the face of a hostile environ-ment, the integrity of many tissues in the adult organism is maintained by a constant replacement of cells. This involves a hierarchical organization of the tissue with rare multi-potent stem cells giving rise to proliferating cells of limited proliferative capacity which in turn produce differentiating cells.

  4. Allogeneic Mesenchymal Stem Cell Treatment Induces Specific Alloantibodies in Horses

    Directory of Open Access Journals (Sweden)

    Sean D. Owens

    2016-01-01

    Full Text Available Background. It is unknown whether horses that receive allogeneic mesenchymal stem cells (MSCs injections develop specific humoral immune response. Our goal was to develop and validate a flow cytometric MSC crossmatch procedure and to determine if horses that received allogeneic MSCs in a clinical setting developed measurable antibodies following MSC administration. Methods. Serum was collected from a total of 19 horses enrolled in 3 different research projects. Horses in the 3 studies all received unmatched allogeneic MSCs. Bone marrow (BM or adipose tissue derived MSCs (ad-MSCs were administered via intravenous, intra-arterial, intratendon, or intraocular routes. Anti-MSCs and anti-bovine serum albumin antibodies were detected via flow cytometry and ELISA, respectively. Results. Overall, anti-MSC antibodies were detected in 37% of the horses. The majority of horses (89% were positive for anti-bovine serum albumin (BSA antibodies prior to and after MSC injection. Finally, there was no correlation between the amount of anti-BSA antibody and the development of anti-MSC antibodies. Conclusion. Anti allo-MSC antibody development was common; however, the significance of these antibodies is unknown. There was no correlation between either the presence or absence of antibodies and the percent antibody binding to MSCs and any adverse reaction to a MSC injection.

  5. Lineage-specific reprogramming as a strategy for cell therapy.

    Science.gov (United States)

    Darabi, Radbod; Perlingeiro, Rita C R

    2008-06-15

    Embryonic stem (ES) cells are endowed with extensive ability for self renewal and differentiation. These features make them a promising candidate for cell therapy. However, despite the enthusiasm and hype surrounding the potential therapeutic use of human ES cells and more recently induced pluripotent stem (iPS) cells, to date few reports have documented successful therapeutic outcome with ES-derived cell populations. This is probably due to two main caveats associated with ES cells, their capacity to form teratomas and the challenge of isolating the appropriate therapeutic cell population from differentiating ES cells. We have focused our efforts on the derivation of skeletal muscle progenitors from ES cells and here we will discuss the strategy of reprogramming lineage choices by overexpression of a master regulator, which has proven successful for the generation of the skeletal myogenic lineage from mouse ES cells.

  6. Antiangiogenic Agent Might Upgrade tumor Cell Sensitivity to Ionizing Radiation

    International Nuclear Information System (INIS)

    The understanding of the fundamental role of angiogenesis and metastasis in cancer growth has led to tremendous interest in research regarding its regulatory mechanisms and clinical implications in the management of cancer. The present study was conducted to evaluate the influence of the angiogenic regulators modification on the tumor growth and the cell sensitivity to ionizing radiation targeting the improvement of cancer therapeutic protocols. Accordingly, the antiangiogenic activity of apigenin and selenium was tested in vitro via MTT assay. The action of Apigenin and or Selenium was examined in vivo by using a model of solid tumor carcinoma (EAC). The growth rate of solid tumor in all experimental groups was measured by Caliper. The irradiated mice were exposed to 6.5 Gy of gamma rays. Apigenin 50 mg/kg body weight and selenium 5 μg per mice were daily administrated for 14 consecutive days after tumor volume reached 1mm3. The angiogenic activators TNF-α (key cytokine) in spleen, serum MMP 2 and MMP 9, liver and tumor NO, the lipid peroxidation (LPx) and angiogenic inhibitor TIMP-1 in spleen as well as, antioxidant markers (CAT, SOD, GPX) in tumor and liver tissue and DNA fragmentation in splenocytes were estimated to monitor efficacy of Apigenin and selenium in cancer treatment strategy. All parameters were determined as a time course on days 16 and 22 after tumor volume reached 1mm3. The using of MTT assay on EAC cells shows inhibition in EAC cell proliferation after the incubation with apigenin and /or selenium. The administration of apigenin and /or selenium to mice bearing tumor and to irradiated mice bearing tumor reduce significantly the TNF-α expression, MMP 2,9 , NO , LPx level and increased the antioxidant enzymes (GPx , SOD and CAT) activities. The DNA fragmentation and the antiangiogenic factors TIMP-1 were significantly increased when compared with their values in mice bearing tumor or in irradiated mice bearing tumor. From the results obtained

  7. Dose-dependence, sex- and tissue-specificity, and persistence of radiation-induced genomic DNA methylation changes

    International Nuclear Information System (INIS)

    Radiation is a well-known genotoxic agent and human carcinogen that gives rise to a variety of long-term effects. Its detrimental influence on cellular function is actively studied nowadays. One of the most analyzed, yet least understood long-term effects of ionizing radiation is transgenerational genomic instability. The inheritance of genomic instability suggests the possible involvement of epigenetic mechanisms, such as changes of the methylation of cytosine residues located within CpG dinucleotides. In the current study we evaluated the dose-dependence of the radiation-induced global genome DNA methylation changes. We also analyzed the effects of acute and chronic high dose (5 Gy) exposure on DNA methylation in liver, spleen, and lung tissues of male and female mice and evaluated the possible persistence of the radiation-induced DNA methylation changes. Here we report that radiation-induced DNA methylation changes were sex- and tissue-specific, dose-dependent, and persistent. In parallel we have studied the levels of DNA damage in the exposed tissues. Based on the correlation between the levels of DNA methylation and DNA damage we propose that radiation-induced global genome DNA hypomethylation is DNA repair-related

  8. Strategies To Assess Hypoxic/HIF-1-Active Cancer Cells for the Development of Innovative Radiation Therapy

    International Nuclear Information System (INIS)

    Local tumor recurrence and distant tumor metastasis frequently occur after radiation therapy and result in the death of cancer patients. These problems are caused, at least in part, by a tumor-specific oxygen-poor microenvironment, hypoxia. Oxygen-deprivation is known to inhibit the chemical ionization of both intracellular macro-molecules and water, etc., and thus reduce the cytotoxic effects of radiation. Moreover, DNA damage produced by free radicals is known to be more repairable under hypoxia than normoxia. Hypoxia is also known to induce biological tumor radioresistance through the activation of a transcription factor, hypoxia-inducible factor 1 (HIF-1). Several potential strategies have been devised in radiation therapy to overcome these problems; however, they have not yet achieved a complete remission. It is essential to reveal the intratumoral localization and dynamics of hypoxic/HIF-1-active tumor cells during tumor growth and after radiation therapy, then exploit the information to develop innovative therapeutic strategies, and finally damage radioresistant cells. In this review, we overview problems caused by hypoxia/HIF-1-active cells in radiation therapy for cancer and introduce strategies to assess intratumoral hypoxia/HIF-1 activity

  9. SU-E-T-565: RAdiation Resistance of Cancer CElls Using GEANT4 DNA: RACE

    International Nuclear Information System (INIS)

    Purpose: The objective of the RACE project is to develop a comparison between Monte Carlo simulation using the Geant4-DNA toolkit and measurements of radiation damage on 3D melanoma and chondrosarcoma culture cells coupled with gadolinium nanoparticles. We currently expose the status of the developments regarding simulations. Methods: Monte Carlo studies are driven using the Geant4 toolkit and the Geant4-DNA extension. In order to model the geometry of a cell population, the opensource CPOP++ program is being developed for the geometrical representation of 3D cell populations including a specific cell mesh coupled with a multi-agent system. Each cell includes cytoplasm and nucleus. The correct modeling of the cell population has been validated with confocal microscopy images of spheroids. The Geant4 Livermore physics models are used to simulate the interactions of a 250 keV X-ray beam and the production of secondaries from gadolinium nanoparticles supposed to be fixed on the cell membranes. Geant4-DNA processes are used to simulate the interactions of charged particles with the cells. An atomistic description of the DNA molecule, from PDB (Protein Data Bank) files, is provided by the so-called PDB4DNA Geant4 user application we developed to score energy depositions in DNA base pairs and sugar-phosphate groups. Results: At the microscopic level, our simulations enable assessing microscopic energy distribution in each cell compartment of a realistic 3D cell population. Dose enhancement factors due to the presence of gadolinium nanoparticles can be estimated. At the nanometer scale, direct damages on nuclear DNA are also estimated. Conclusion: We successfully simulated the impact of direct radiations on a realistic 3D cell population model compatible with microdosimetry calculations using the Geant4-DNA toolkit. Upcoming validation and the future integration of the radiochemistry module of Geant4-DNA will propose to correlate clusters of ionizations with in vitro

  10. SU-E-T-565: RAdiation Resistance of Cancer CElls Using GEANT4 DNA: RACE

    Energy Technology Data Exchange (ETDEWEB)

    Perrot, Y; Payno, H; Delage, E; Maigne, L [Clermont Universite, CNRS/IN2P3, Laboratoire de Physique Corpusculaire de Clermont-Ferrand, Aubiere (France); Incerti, S [Universite Bordeaux 1, CNRS/IN2P3, Centres d' Etudes Nucleaires de Bordeaux-Gradignan, Gradignan (France); Debiton, E; Peyrode, C; Chezal, J; Miot-Noirault, E; Degoul, F [Clermont Universite, Universite d' Auvergne, Imagerie Moleculaire et Therapie Vectorisee, INSERM U990, Centre Jean Perrin, Clermont-Ferrand (France)

    2014-06-01

    Purpose: The objective of the RACE project is to develop a comparison between Monte Carlo simulation using the Geant4-DNA toolkit and measurements of radiation damage on 3D melanoma and chondrosarcoma culture cells coupled with gadolinium nanoparticles. We currently expose the status of the developments regarding simulations. Methods: Monte Carlo studies are driven using the Geant4 toolkit and the Geant4-DNA extension. In order to model the geometry of a cell population, the opensource CPOP++ program is being developed for the geometrical representation of 3D cell populations including a specific cell mesh coupled with a multi-agent system. Each cell includes cytoplasm and nucleus. The correct modeling of the cell population has been validated with confocal microscopy images of spheroids. The Geant4 Livermore physics models are used to simulate the interactions of a 250 keV X-ray beam and the production of secondaries from gadolinium nanoparticles supposed to be fixed on the cell membranes. Geant4-DNA processes are used to simulate the interactions of charged particles with the cells. An atomistic description of the DNA molecule, from PDB (Protein Data Bank) files, is provided by the so-called PDB4DNA Geant4 user application we developed to score energy depositions in DNA base pairs and sugar-phosphate groups. Results: At the microscopic level, our simulations enable assessing microscopic energy distribution in each cell compartment of a realistic 3D cell population. Dose enhancement factors due to the presence of gadolinium nanoparticles can be estimated. At the nanometer scale, direct damages on nuclear DNA are also estimated. Conclusion: We successfully simulated the impact of direct radiations on a realistic 3D cell population model compatible with microdosimetry calculations using the Geant4-DNA toolkit. Upcoming validation and the future integration of the radiochemistry module of Geant4-DNA will propose to correlate clusters of ionizations with in vitro

  11. A cell-based high-throughput screening assay for radiation susceptibility using automated cell counting

    International Nuclear Information System (INIS)

    Radiotherapy is one of the mainstays in the treatment for cancer, but its success can be limited due to inherent or acquired resistance. Mechanisms underlying radioresistance in various cancers are poorly understood and available radiosensitizers have shown only modest clinical benefit. There is thus a need to identify new targets and drugs for more effective sensitization of cancer cells to irradiation. Compound and RNA interference high-throughput screening technologies allow comprehensive enterprises to identify new agents and targets for radiosensitization. However, the gold standard assay to investigate radiosensitivity of cancer cells in vitro, the colony formation assay (CFA), is unsuitable for high-throughput screening. We developed a new high-throughput screening method for determining radiation susceptibility. Fast and uniform irradiation of batches up to 30 microplates was achieved using a Perspex container and a clinically employed linear accelerator. The readout was done by automated counting of fluorescently stained nuclei using the Acumen eX3 laser scanning cytometer. Assay performance was compared to that of the CFA and the CellTiter-Blue homogeneous uniform-well cell viability assay. The assay was validated in a whole-genome siRNA library screening setting using PC-3 prostate cancer cells. On 4 different cancer cell lines, the automated cell counting assay produced radiation dose response curves that followed a linear-quadratic equation and that exhibited a better correlation to the results of the CFA than did the cell viability assay. Moreover, the cell counting assay could be used to detect radiosensitization by silencing DNA-PKcs or by adding caffeine. In a high-throughput screening setting, using 4 Gy irradiated and control PC-3 cells, the effects of DNA-PKcs siRNA and non-targeting control siRNA could be clearly discriminated. We developed a simple assay for radiation susceptibility that can be used for high-throughput screening. This will aid

  12. Radiation-induced VEGF-C expression and endothelial cell proliferation in lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yu-Hsuan [National Taiwan University Hospital, Department of Oncology, Taipei (China); National Taiwan University, Pharmacological Institute, College of Medicine, Taipei (China); Pan, Shiow-Lin; Wang, Jing-Chi; Teng, Che-Ming [National Taiwan University, Pharmacological Institute, College of Medicine, Taipei (China); Kuo, Sung-Hsin [National Taiwan University Hospital, Department of Oncology, Taipei (China); National Taiwan University College of Medicine, Department of Internal Medicine, Taipei (China); Cheng, Jason Chia-Hsien [National Taiwan University Hospital, Department of Oncology, Taipei (China); National Taiwan University College of Medicine, Graduate Institute of Clinical Medicine, Taipei (China)

    2014-12-15

    The present study was undertaken to investigate whether radiation induces the expression of vascular endothelial growth factor C (VEGF-C) through activation of the PI3K/Akt/mTOR pathway,subsequently affecting endothelial cells. Radiotherapy-induced tumor micro-lymphatic vessel density (MLVD) was determined in a lung cancer xenograft model established in SCID mice. The protein expression and phosphorylation of members of the PI3K/Akt/mTOR pathway and VEGF-C secretion and mRNA expression in irradiated lung cancer cells were assessed by Western blot analysis, enzyme-linked immunosorbent assays (ELISAs), and reverse transcriptase-polymerase chain reaction (RT-PCR). Moreover, specific chemical inhibitors were used to evaluate the role of the PI3K/Akt/mTOR signaling pathway. Conditioned medium (CM) from irradiated control-siRNA or VEGF-C-siRNA-expressing A549 cells was used to evaluate the proliferation of endothelial cells by the MTT assay. Radiation increased VEGF-C expression in a dose-dependent manner over time at the protein but not at the mRNA level. Radiation also up-regulated the phosphorylation of Akt, mTOR, 4EBP, and eIF4E, but not of p70S6K. Radiation-induced VEGF-C expression was down-regulated by LY294002 and rapamycin (both p < 0.05). Furthermore, CM from irradiated A549 cells enhanced human umbilical vein endothelial cell (HUVEC) and lymphatic endothelial cell (LEC) proliferation, which was not observed with CM from irradiated VEGF-C-siRNA-expressing A549 cells. Radiation-induced activation of the PI3K/Akt/mTOR signaling pathway increases VEGF-C expression in lung cancer cells, thereby promoting endothelial cell proliferation. (orig.) [German] Die vorliegende Studie untersucht, ob die Strahlung die Expression von VEGF-C (vascular endothelial growth factor C) mittels Aktivierung des PI3K/Akt/mTOR-Signalwegs induziert und anschliessend die endothelialen Zellen beeinflusst. Die durch Strahlentherapie induzierte Mikrolymphgefaessdichte (MLVD) im Tumor wurde in

  13. Species-specific transformation of T cells by HVMNE

    International Nuclear Information System (INIS)

    HVMNE is an Epstein-Barr virus (EBV)-like lymphocryptovirus (LCV) originally isolated from a Macaca nemestrina with CD8+ T cell mycosis fungoides/cutaneous T cell lymphoma (Blood 98 (2001), 2193). HVMNE transforms rabbit T cells in vitro and causes T cell lymphoma in New Zealand white rabbits. Here we demonstrate that HVMNE also immortalizes T cells from mustached tamarins but not those from owl monkeys, common marmosets, squirrel monkeys, black-capped capuchins, and humans. Cytogenetic and FACS analysis revealed the true origin and T cell lineage of the transformed tamarin T cell lines. Tamarin T cells contained HVMNE DNA sequence and displayed a decreased requirement for the IL-2 cytokine for growth. Thus, this EBV-like virus from M. nemestrina differs from the other EBV-like viruses found in nonhuman primates inasmuch as it appears to preferentially transform T cells

  14. Study on production of useful metabolites by development of advanced cell culture techniques using radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Byung Yeoup; Kim, Jinhong; Lee, Seung Sik; Bai, Hyounwoo; An, Byung Chull; Lee, Eun Mi; Lee, Jae Taek; Kim, Mi Ja

    2010-12-15

    The purpose of this project is improvement of investigation, materialization and evaluation techniques on effectiveness for functional natural compounds throughout development of tissue/cell culture techniques for mass production of useful metabolites using radiation. Research scope includes Development of a technique for radiation tissue and cell culture, Database construction for radiation response in plants and radiation effects, Construction of general-purpose national based techniques of cell culture technique using radiation. Main results are as follow: Isolation and identification of radiation induced basI gene; Determination of stresses sensitivities by transformating basI gene into arabidopsis; Isolation and identification of radiation induced chaperon proteins (PaAhpC and yPrxII) from Pseudomonas and yeast, and structural and functional analysis of the proteins; Determination of oxidative and heat resistance by transformating PaAhpC; Isolation and identification of maysin and its derivatives from centipedgrass; Investigation of enhancement technique for improving maysin and its derivatives production using radiation; Investigation of removing undesirable color in maysin and its derivatives using radiation; Determination of the effect of radiation on physiological functions of centipedgrass extracts; Identification of H{sub 2}O{sub 2} removing enzyme in radiation irradiated plant (Spinach); Determination of the effects of centipedgrass extracts on anti-obesity and anti-cancer activities.

  15. Isolate-specific effects of ultraviolet radiation on photosynthesis, growth and mycosporine-like amino acids in the microbial mat-forming cyanobacterium Microcoleus chthonoplastes.

    Science.gov (United States)

    Pattanaik, Bagmi; Roleda, Michael Y; Schumann, Rhena; Karsten, Ulf

    2008-03-01

    Microcoleus chthonoplastes constitutes one of the dominant microorganisms in intertidal microbial mat communities. In the laboratory, the effects of repeated daily exposure to ultraviolet radiation (16:8 light:dark cycle) was investigated in unicyanobacterial cultures isolated from three different localities (Baltic Sea = WW6; North Sea = STO and Brittany = BRE). Photosynthesis and growth were measured in time series (12-15 days) while UV-absorbing mycosporine-like amino acids (MAAs) and cellular integrity were determined after 12 and 3 days exposure to three radiation treatments [PAR (22 mumol photon m(-2) s(-1)) = P; PAR + UV-A (8 W m(-2)) = PA; PAR + UV-A + UV-B (0.4 W m(-2)) = PAB]. Isolate-specific responses to UVR were observed. The proximate response to radiation stress after 1-day treatment showed that isolate WW6 was the most sensitive to UVR. However, repeated exposure to radiation stress indicated that photosynthetic efficiency (F (v)/F (m)) of WW6 acclimated to UVR. Conversely, although photosynthesis in STO exhibited lower reduction in F (v)/F (m) during the first day, the values declined over time. The BRE isolate was the most tolerant to radiation stress with the lowest reduction in F (v)/F (m )sustained over time. While photosynthetic efficiencies of different isolates were able to acclimate to UVR, growth did not. The discrepancy seems to be due to the higher cell density used for photosynthesis compared to the growth measurement. Apparently, the cell density used for photosynthesis was not high enough to offer self-shading protection because cellular damage was also observed in those filaments under UVR. Most likely, the UVR acclimation of photosynthesis reflects predominantly the performance of the surviving cells within the filaments. Different strategies were observed in MAAs synthesis. Total MAAs content in WW6 was not significantly different between all the radiation treatments. In contrast, the additional fluence of UV-A and UV

  16. miR-15a/16 Enhances Radiation Sensitivity of Non-Small Cell Lung Cancer Cells by Targeting the TLR1/NF-κB Signaling Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Lan, Fengming [Radiation Oncology Department, PLA Airforce General Hospital, Beijing (China); Radiation Oncology Department, Tianjin Hospital, Tianjin (China); Yue, Xiao [Tianjin Huanhu Hospital, Tianjin Neurosurgery Institute, Tianjin (China); Ren, Gang; Li, Hongqi; Ping, Li; Wang, Yingjie [Radiation Oncology Department, PLA Airforce General Hospital, Beijing (China); Xia, Tingyi, E-mail: xiatingyi1959@163.com [Radiation Oncology Department, PLA Airforce General Hospital, Beijing (China)

    2015-01-01

    Purpose: Many miRNAs have been identified as essential issues and core determining factors in tumor radiation. Recent reports have demonstrated that miRNAs and Toll-like receptors could exert reciprocal effects to control cancer development in various ways. However, a novel role of miR-15a/16 in enhancing radiation sensitivity by directly targeting TLR1 has not been reported, to our knowledge. Methods and Materials: Bioinformatic analyses, luciferase reporter assay, biochemical assays, and subcutaneous tumor establishment were used to characterize the signaling pathways of miRNA-15a/16 in response to radiation treatment. Results: First, an inverse correlation between the expression of miR-15a/16 and TLR1 protein was revealed in non-small cell lung cancer (NSCLC) and normal lung tissues. Next, we corroborated that miR-15a/16 specifically bound to TLR1 3′UTR and inhibited the expression of TLR1 in H358 and A549 cells. Furthermore, miR-15a/16 downregulated the activity of the NF-κB signaling pathway through TLR1. In addition, overexpression of miR-15a/16 inhibited survival capability and increased radiation-induced apoptosis, resulting in enhancement of radiosensitivity in H358 and A549 cells. Finally, subcutaneous tumor bearing NSCLC cells in a nude mice model was established, and the results showed that combined groups (miR-15a/16 + radiation) inhibited tumor growth more significantly than did radiation alone. Conclusions: We mainly elucidate that miRNA-15a/16 can enhance radiation sensitivity by regulating the TLR1/NF-κB signaling pathway and act as a potential therapeutic approach to overcome radioresistance for lung cancer treatment.

  17. miR-15a/16 Enhances Radiation Sensitivity of Non-Small Cell Lung Cancer Cells by Targeting the TLR1/NF-κB Signaling Pathway

    International Nuclear Information System (INIS)

    Purpose: Many miRNAs have been identified as essential issues and core determining factors in tumor radiation. Recent reports have demonstrated that miRNAs and Toll-like receptors could exert reciprocal effects to control cancer development in various ways. However, a novel role of miR-15a/16 in enhancing radiation sensitivity by directly targeting TLR1 has not been reported, to our knowledge. Methods and Materials: Bioinformatic analyses, luciferase reporter assay, biochemical assays, and subcutaneous tumor establishment were used to characterize the signaling pathways of miRNA-15a/16 in response to radiation treatment. Results: First, an inverse correlation between the expression of miR-15a/16 and TLR1 protein was revealed in non-small cell lung cancer (NSCLC) and normal lung tissues. Next, we corroborated that miR-15a/16 specifically bound to TLR1 3′UTR and inhibited the expression of TLR1 in H358 and A549 cells. Furthermore, miR-15a/16 downregulated the activity of the NF-κB signaling pathway through TLR1. In addition, overexpression of miR-15a/16 inhibited survival capability and increased radiation-induced apoptosis, resulting in enhancement of radiosensitivity in H358 and A549 cells. Finally, subcutaneous tumor bearing NSCLC cells in a nude mice model was established, and the results showed that combined groups (miR-15a/16 + radiation) inhibited tumor growth more significantly than did radiation alone. Conclusions: We mainly elucidate that miRNA-15a/16 can enhance radiation sensitivity by regulating the TLR1/NF-κB signaling pathway and act as a potential therapeutic approach to overcome radioresistance for lung cancer treatment

  18. The space experiment CERASP: Definition of a space-suited radiation source and growth conditions for human cells

    Science.gov (United States)

    Hellweg, Christine E.; Baumstark-Khan, Christa; Spitta, Luis; Thelen, Melanie; Arenz, Andrea; Franz, Markus; Schulze-Varnholt, Dirk; Berger, Thomas; Reitz, Günther

    The combined action of ionizing radiation and microgravity will continue to influence future space missions, with special risks for astronauts on the Moon surface or for long duration missions to Mars. It has been estimated that on a 3-year mission to Mars about 3% of the bodies' cell nuclei would have been hit by one iron ion with the consequence that nuclear DNA will be heavily damaged. There is increasing evidence that basic cellular functions are sensitive not only to radiation but also to microgravity. DNA repair studies in space on bacteria, yeast cells and human fibroblasts, which were irradiated before, flight, gave contradictory results: from inhibition of repair by microgravity to enhancement, whereas others did not detect any influence of microgravity on repair. The space experiment CERASP (CEllular Responses to RAdiation in SPace) to be performed at the International Space Station (ISS) is aimed to supply basic information on the cellular response in microgravity to radiation applied during flight. It makes use of a recombinant human cell line as reporter for cellular signal transduction modulation by genotoxic environmental conditions. The main biological endpoints under investigation will be gene activation based on enhanced green fluorescent protein (EGFP, originally isolated from the bioluminescent jellyfish Aequorea victoria) expression controlled by a DNA damage-dependent promoter element which reflects the activity of the nuclear factor kappa B (NF- κB) pathway. The NF- κB family of proteins plays a major role in the inflammatory and immune response, cell proliferation and differentiation, anti-apoptosis and tumorgenesis. For radiation exposure during space flight a radiation source has been constructed as damage accumulation by cosmic radiation will certainly be insufficient for analysis. The space experiment specific hardware consists of a specially designed radiation source made up of the β-emitter promethium-147, combined with a

  19. ACE2 is required for daughter cell-specific G1 delay in Saccharomyces cerevisiae

    OpenAIRE

    Laabs, Tracy L.; Markwardt, David D.; Slattery, Matthew G.; Newcomb, Laura L.; Stillman, David J.; Heideman, Warren

    2003-01-01

    Saccharomyces cerevisiae cells reproduce by budding to yield a mother cell and a smaller daughter cell. Although both mother and daughter begin G1 simultaneously, the mother cell progresses through G1 more rapidly. Daughter cell G1 delay has long been thought to be due to a requirement for attaining a certain critical cell size before passing the commitment point in the cell cycle known as START. We present an alternative model in which the daughter cell-specific Ace2 ...

  20. Autophagy promotes radiation-induced senescence but inhibits bystander effects in human breast cancer cells.

    Science.gov (United States)

    Huang, Yao-Huei; Yang, Pei-Ming; Chuah, Qiu-Yu; Lee, Yi-Jang; Hsieh, Yi-Fen; Peng, Chih-Wen; Chiu, Shu-Jun

    2014-07-01

    Ionizing radiation induces cellular senescence to suppress cancer cell proliferation. However, it also induces deleterious bystander effects in the unirradiated neighboring cells through the release of senescence-associated secretory phenotypes (SASPs) that promote tumor progression. Although autophagy has been reported to promote senescence, its role is still unclear. We previously showed that radiation induces senescence in PTTG1-depleted cancer cells. In this study, we found that autophagy was required for the radiation-induced senescence in PTTG1-depleted breast cancer cells. Inhibition of autophagy caused the cells to switch from radiation-induced senescence to apoptosis. Senescent cancer cells exerted bystander effects by promoting the invasion and migration of unirradiated cells through the release of CSF2 and the subsequently activation of the JAK2-STAT3 and AKT pathways. However, the radiation-induced bystander effects were correlated with the inhibition of endogenous autophagy in bystander cells, which also resulted from the activation of the CSF2-JAK2 pathway. The induction of autophagy by rapamycin reduced the radiation-induced bystander effects. This study reveals, for the first time, the dual role of autophagy in radiation-induced senescence and bystander effects.

  1. Raman spectroscopy of single human tumour cells exposed to ionizing radiation in vitro

    International Nuclear Information System (INIS)

    This work investigates the capability of Raman spectroscopy (RS) to study the effects of ionizing radiation on single human tumour cells. Prostate tumour cells (cell line DU145) are cultured in vitro and irradiated to doses between 15 and 50 Gy with single fractions of 6 MV photons. Single-cell Raman spectra are acquired from irradiated and unirradiated cultures up to 5 days post-irradiation. Principal component analysis is used to distinguish the uniquely radiation-induced spectral changes from inherent sources of spectral variability arising from cell cycle differences and other known factors. We observe uniquely radiation-induced spectral changes which are correlated with both the irradiated dose and the incubation time post-irradiation. The spectral changes induced by radiation arise from biochemical differences in lipids, nucleic acids, amino acids and conformational protein structures between irradiated and unirradiated cells. To our knowledge, this study is the first use of RS to observe radiation-induced biochemical differences in single cells, and is the first use of vibrational spectroscopy to observe uniquely radiation-induced biochemical differences in single cells independent of concurrent cell-cycle- or cell-death-related processes.

  2. Specifications

    International Nuclear Information System (INIS)

    As part of the Danish RERTR Program, three fuel elements with LEU U3O8-Al fuel and three fuel elements with LEU U3Si2-Al fuel were manufactured by NUKEM for irradiation testing in the DR-3 reactor at the Risoe National Laboratory in Denmark. The specifications for the elements with U3O8-Al fuel are presented here as an illustration only. Specifications for the elements with U3Si2-Al fuel were very similar. In this example, materials, material numbers, documents numbers, and drawing numbers specific to a single fabricator have been deleted. (author)

  3. Tissue-specific designs of stem cell hierarchies

    NARCIS (Netherlands)

    Visvader, Jane E; Clevers, Hans

    2016-01-01

    Recent work in the field of stem cell biology suggests that there is no single design for an adult tissue stem cell hierarchy, and that different tissues employ distinct strategies to meet their self-renewal and repair requirements. Stem cells may be multipotent or unipotent, and can exist in quiesc

  4. Tinnitus and cell phones: the role of electromagnetic radiofrequency radiation

    Directory of Open Access Journals (Sweden)

    Luisa Nascimento Medeiros

    2016-02-01

    Full Text Available ABSTRACT INTRODUCTION: Tinnitus is a multifactorial condition and its prevalence has increased on the past decades. The worldwide progressive increase of the use of cell phones has exposed the peripheral auditory pathways to a higher dose of electromagnetic radiofrequency radiation (EMRFR. Some tinnitus patients report that the abusive use of mobiles, especially when repeated in the same ear, might worsen ipsilateral tinnitus. OBJECTIVE: The aim of this study was to evaluate the available evidence about the possible causal association between tinnitus and exposure to electromagnetic waves. METHODS: A literature review was performed searching for the following keywords: tinnitus, electromagnetic field, mobile phones, radio frequency, and electromagnetic hypersensitivity. We selected 165 articles that were considered clinically relevant in at least one of the subjects. RESULTS: EMRFR can penetrate exposed tissues and safety exposure levels have been established. These waves provoke proved thermogenic effects and potential biological and genotoxic effects. Some individuals are more sensitive to electromagnetic exposure (electrosensitivity, and thus, present earlier symptoms. There may be a common pathophysiology between this electrosensitivity and tinnitus. CONCLUSION: There are already reasonable evidences to suggest caution for using mobile phones to prevent auditory damage and the onset or worsening of tinnitus.

  5. Cell proliferation during fractionated radiation in two experimental tumors

    International Nuclear Information System (INIS)

    Tumor cell proliferation kinetics after irradiation have been studied using the method of bromodeoxyuridine incorporation and flow cytometry. Labelling indices were obtained after single and multiple fractions of radiation in a mouse fibrosarcoma (FSa-II) and human squamous carcinoma (FADU) growing in nude mice. For 8 mm tumors mean L.I was 17.5 +- 2.6% and 21.5 + 3.2%, respectively. Both tumors showed a similar response to single dose of irradiation (10 and 20 Gy) with initial depression of labelling index and then a rapid increase after 3 days in the FSa-II tumors (mean L.I 24%) and 5 days in the FADU tumors (mean L.I 27%). During fractionated treatment, labelling index was dependent on dose per fraction (2.5-18 Gy) time interval between fractions and time of analysis. Tumors were biopsied during course of fractionated treatment to see if labelling index would act as a predictor of response. No significant difference could be determined between individual tumors that had received the same dose per fraction. However a labelling index the same or higher than control values were associated with lack of tumor control. Controlled tumors showed a significant depression of labelling index (rho<0.05)

  6. Using patient-specific phantoms to evaluate deformable image registration algorithms for adaptive radiation therapy.

    Science.gov (United States)

    Stanley, Nick; Glide-Hurst, Carri; Kim, Jinkoo; Adams, Jeffrey; Li, Shunshan; Wen, Ning; Chetty, Indrin J; Zhong, Hualiang

    2013-11-04

    The quality of adaptive treatment planning depends on the accuracy of its underlying deformable image registration (DIR). The purpose of this study is to evaluate the performance of two DIR algorithms, B-spline-based deformable multipass (DMP) and deformable demons (Demons), implemented in a commercial software package. Evaluations were conducted using both computational and physical deformable phantoms. Based on a finite element method (FEM), a total of 11 computational models were developed from a set of CT images acquired from four lung and one prostate cancer patients. FEM generated displacement vector fields (DVF) were used to construct the lung and prostate image phantoms. Based on a fast-Fourier transform technique, image noise power spectrum was incorporated into the prostate image phantoms to create simulated CBCT images. The FEM-DVF served as a gold standard for verification of the two registration algorithms performed on these phantoms. The registration algorithms were also evaluated at the homologous points quantified in the CT images of a physical lung phantom. The results indicated that the mean errors of the DMP algorithm were in the range of 1.0 ~ 3.1 mm for the computational phantoms and 1.9 mm for the physical lung phantom. For the computational prostate phantoms, the corresponding mean error was 1.0-1.9 mm in the prostate, 1.9-2.4mm in the rectum, and 1.8-2.1 mm over the entire patient body. Sinusoidal errors induced by B-spline interpolations were observed in all the displacement profiles of the DMP registrations. Regions of large displacements were observed to have more registration errors. Patient-specific FEM models have been developed to evaluate the DIR algorithms implemented in the commercial software package. It has been found that the accuracy of these algorithms is patient dependent and related to various factors including tissue deformation magnitudes and image intensity gradients across the regions of interest. This may suggest that

  7. Effects of deprivation of background environmental radiation on cultured human cells

    International Nuclear Information System (INIS)

    In this paper we present results from an experiment aimed at investigating whether living cells are influenced by background ionizing radiation. Parallel human cell cultures were set-up in two separate laboratories and maintained for several months under identical conditions but for a 80 x different level of background ionizing radiation. Periodically, the cell cultures were monitored for the onset of divergences in biochemical behavior, using two distinct cellular biology assays, namely micronuclei induction and activity of enzymes implicated in the management of oxidative stress. To reveal any subtle modifications, responses were also amplified by subjecting cell cultures to acute stress induced by exposure to moderately high doses of ionizing radiation. Compared to reference radiation background conditions, cultures maintained in a reduced background radiation environment handled the consequences of acute stress with diminished efficacy.

  8. Bio-molecular alterations induced by a chemical or radiating stress in isolated human cells

    International Nuclear Information System (INIS)

    After having recalled some aspects of radiobiology (effects of ionizing radiations, molecular targets of radiations, cellular responses with respect to the radiation), the author discusses various aspects of radio-sensitivity: intrinsic radio-sensitivity of tumoral and normal cells, DNA injuries and in vitro radio-sensitivity, genes of susceptibility to ionizing radiations, clustered injuries. Then she reports investigations performed by infrared micro-spectroscopy: characterization of pathological lines, of biological processes, of oxidative injuries induced by xenobiotics, of injuries induced by ionizing radiations

  9. Equal modulation of endothelial cell function by four distinct tissue-specific mesenchymal stem cells.

    Science.gov (United States)

    Lin, Ruei-Zeng; Moreno-Luna, Rafael; Zhou, Bin; Pu, William T; Melero-Martin, Juan M

    2012-09-01

    Mesenchymal stem cells (MSCs) can generate multiple end-stage mesenchymal cell types and constitute a promising population of cells for regenerative therapies. Additionally, there is increasing evidence supporting other trophic activities of MSCs, including the ability to enable formation of vasculature in vivo. Although MSCs were originally isolated from the bone marrow, the presence of these cells in the stromal vascular fraction of multiple adult tissues has been recently recognized. However, it is unknown whether the capacity to modulate vasculogenesis is ubiquitous to all MSCs regardless of their tissue of origin. Here, we demonstrated that tissue-resident MSCs isolated from four distinct tissues have equal capacity to modulate endothelial cell function, including formation of vascular networks in vivo. MSCs were isolated from four murine tissues, including bone marrow, white adipose tissue, skeletal muscle, and myocardium. In culture, all four MSC populations secreted a plethora of pro-angiogenic factors that unequivocally induced proliferation, migration, and tube formation of endothelial colony-forming cells (ECFCs). In vivo, co-implantation of MSCs with ECFCs into mice generated an extensive network of blood vessels with ECFCs specifically lining the lumens and MSCs occupying perivascular positions. Importantly, there were no differences among all four MSCs evaluated. Our studies suggest that the capacity to modulate the formation of vasculature is a ubiquitous property of all MSCs, irrespective of their original anatomical location. These results validate multiple tissues as potential sources of MSCs for future cell-based vascular therapies.

  10. Effects of non-thermal mobile phone radiation on breast adenocarcinoma cells

    OpenAIRE

    Zen Fourie; Dariusz Leszczynski; Sumari Marais; Carin Huyser; Annie M. Joubert; Barend A. Stander

    2011-01-01

    Mobile phone usage currently exceeds landline communication in Africa. The extent of this usage has raised concerns about the long-term health effects of the ongoing use of mobile phones. To assess the physiological effects of radiation from mobile phones in vitro, MCF-7 breast adenocarcinoma cells were exposed to 2W/kg non-thermal 900-MHz mobile phone radiation. The effects investigated were those on metabolic activity, cell morphology, cell cycle progression, phosphatid...

  11. Exposure to cell phone radiations produces biochemical changes in worker honey bees

    OpenAIRE

    Kumar, Neelima R.; Sangwan, Sonika; Badotra, Pooja

    2011-01-01

    The present study was carried out to find the effect of cell phone radiations on various biomolecules in the adult workers of Apis mellifera L. The results of the treated adults were analyzed and compared with the control. Radiation from the cell phone influences honey bees’ behavior and physiology. There was reduced motor activity of the worker bees on the comb initially, followed by en masse migration and movement toward “talk mode” cell phone. The initial quiet period was characterized by ...

  12. Oxidative changes and apoptosis induced by 1800-MHz electromagnetic radiation in NIH/3T3 cells.

    Science.gov (United States)

    Hou, Qingxia; Wang, Minglian; Wu, Shuicai; Ma, Xuemei; An, Guangzhou; Liu, Huan; Xie, Fei

    2015-03-01

    To investigate the potential adverse effects of mobile phone radiation, we studied reactive oxygen species (ROS), DNA damage and apoptosis in mouse embryonic fibroblasts (NIH/3T3) after intermittent exposure (5 min on/10 min off, for various durations from 0.5 to 8 h) to an 1800-MHz GSM-talk mode electromagnetic radiation (EMR) at an average specific absorption rate of 2 W/kg. A 2',7'-dichlorofluorescin diacetate fluorescence probe was used to detect intracellular ROS levels, immunofluorescence was used to detect γH2AX foci as a marker for DNA damage, and flow cytometry was used to measure apoptosis. Our results showed a significant increase in intracellular ROS levels after EMR exposure and it reached the highest level at an exposure time of 1 h (p < 0.05) followed by a slight decrease when the exposure continued for as long as 8 h. No significant effect on the number of γH2AX was detected after EMR exposure. The percentage of late-apoptotic cells in the EMR-exposed group was significantly higher than that in the sham-exposed groups (p < 0.05). These results indicate that an 1800-MHz EMR enhances ROS formation and promotes apoptosis in NIH/3T3 cells.

  13. Mesenchymal stem cell therapy for acute radiation syndrome:Innovative medical approaches in military medicine

    Institute of Scientific and Technical Information of China (English)

    Erik B.Eaton Jr.; Timothy R.Varney

    2014-01-01

    After a radiological or nuclear event, acute radiation syndrome (ARS) will present complex medical challenges that could involve the treatment of hundreds to thousands of patients. Current medical doctrine is based on limited clinical data and remains inadequate. Efforts to develop medical innovations that address ARS complications are unlikely to be generated by the industry because of market uncertainties specific to this type of injury. A prospective strategy could be the integration of cellular therapy to meet the medical demands of ARS. The most clinically advanced cellular therapy to date is the administration of mesenchymal stem cells (MSCs). Results of currently published investigations describing MSC safety and efficacy in a variety of injury and disease models demonstrate the unique qualities of this reparative cell population in adapting to the specific requirements of the damaged tissue in which the cells integrate. This report puts forward a rationale for the further evaluation of MSC therapy to address the current unmet medical needs of ARS. We propose that the exploration of this novel therapy for the treatment of the multivariate complications of ARS could be of invaluable benefit to military medicine.

  14. Cell/Tissue Culture Radiation Exposure Facility Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose the development of automated systems to improve radiobiology research capabilities at NASA Space Radiation Laboratory (NSRL) at Brookhaven National...

  15. Combined effects of C225 and 125-iodine seed radiation on colorectal cancer cells

    International Nuclear Information System (INIS)

    To characterize the effect of combined treatment of the anti-epidermal growth factor receptor (EGFR) monoclonal antibody C225 and 125-iodine (125I) seed radiation in human colorectal cancer. We treated LS180 cells with 125I continuous low dose rate radiation in the presence and absence of 100 nM C225. The clonogenic capacity, cellular proliferation, cell cycle distribution, apoptosis, and molecular pathways of the cells following the treatments were analyzed in vitro. The sensitizer enhancement ratio of C225 was approximately 1.4. Treatment with C225 and radiation alone produced significant inhibition of cell growth, but combination therapy produced greater inhibition than either treatment administered alone. C225 increased the radiation-induced apoptosis and the fraction of γ-H2AX foci positive cells at 48 h after treatment. The Akt phosphorylation level was lower in the cells receiving the combination treatment than in the cells treated with radiation or C225 alone. These findings indicate that C225 sensitizes LS180 cells to 125I seed radiation. Growth inhibition is mediated by inducing apoptosis and not cell cycle arrest. Additionally, we confirmed that C225 impairs DNA repair by reducing the cellular level of the DNA-PKcs and Ku70 proteins. Furthermore, the inhibition of Akt signaling activation may be responsible for the C225-mediated radiosensitization

  16. Effect of low-dose X-ray radiation on adaptive response in gastric cancer cell

    Institute of Scientific and Technical Information of China (English)

    Shukai Wang; Gang Jiang; Hongsheng Yu; Xiangping Liu; Chang Xu

    2013-01-01

    Objective: We aimed to study the effect and mechanism of low-dose radiation (LDR) on adaptive response of gastric cancer cell. Methods: SGC7901 cells were cultured in vitro, and divided into 4 groups: control group (D0 group), low-dose radiation group (D1 group, 75 mGy), high-dose radiation group (D2 group, 2 Gy), low-dose plus high-dose radiation group (D1 + D2 group, 75 mGy + 2 Gy, the interval of low and high-dose radiation being 8 h). Cell inhibition rate was detected by cytometry and CCK8 method; the proportion of cell cycle at different times after irradiation was determined by using a flow cytometry. The ATM mRNA levels were detected by using quantitative real-time reverse transcription polymerase chain reaction (RT-PCR). Results: There was no significant different between groups D0 and D1, groups D2 and D1 + D2 cell inhibition rate (P > 0.05). There was a significant increase G2/M arrest in groups D2 and D1 + D2 than groups D0 and D1 after 6 h of radiation and did not recover at 48 h (P 0.05). Conclusion: LDR cannot induce adaptive response in SGC7901 cells in vitro, which may be associated the regulation of cell cycle, and its ATM mRNA expression cannot be affected by 75 mGy X-ray radiation.

  17. Fractionated radiation exposure amplifies the radioresistant nature of prostate cancer cells

    Science.gov (United States)

    McDermott, N.; Meunier, A.; Mooney, B.; Nortey, G.; Hernandez, C.; Hurley, S.; Lynam-Lennon, N.; Barsoom, S. H.; Bowman, K. J.; Marples, B.; Jones, G. D. D.; Marignol, L.

    2016-01-01

    The risk of recurrence following radiation therapy remains high for a significant number of prostate cancer patients. The development of in vitro isogenic models of radioresistance through exposure to fractionated radiation is an increasingly used approach to investigate the mechanisms of radioresistance in cancer cells and help guide improvements in radiotherapy standards. We treated 22Rv1 prostate cancer cells with fractionated 2 Gy radiation to a cumulative total dose of 60 Gy. This process selected for 22Rv1-cells with increased clonogenic survival following subsequent radiation exposure but increased sensitivity to Docetaxel. This RR-22Rv1 cell line was enriched in S-phase cells, less susceptible to DNA damage, radiation-induced apoptosis and acquired enhanced migration potential, when compared to wild type and aged matched control 22Rv1 cells. The selection of radioresistant cancer cells during fractionated radiation therapy may have implications in the development and administration of future targeted therapy in conjunction with radiation therapy. PMID:27703211

  18. Plant lectin, ATF1011, on the tumor cell surface augments tumor-specific immunity through activation of T cells specific for the lectin.

    Science.gov (United States)

    Yoshimoto, R; Kondoh, N; Isawa, M; Hamuro, J

    1987-01-01

    The possibility that a plant lectin as a carrier protein would specifically activate T cells, resulting in the augmentation of antitumor immunity was investigated. ATF1011, a nonmitogenic lectin for T cells purified from Aloe arborescens Mill, bound equally to normal and tumor cells. ATF1011 binding on the MM102 tumor cell surfaces augmented anti-trinitrophenyl (TNP) antibody production of murine splenocytes when the mice were primarily immunized with TNP-conjugated MM102 tumor cells. The alloreactive cytotoxic T cell response was also augmented by allostimulator cells binding ATF1011 on the cell surfaces. These augmented responses may be assumed to be mediated by the activation of helper T cells recognizing ATF1011 as a carrier protein. Killer T cells were induced against ATF1011 antigen in the H-2 restricted manner using syngeneic stimulator cells bearing ATF1011 on the cell surfaces. When this lectin was administered intralesionally into the tumors, induction of cytotoxic effector cells was demonstrated. These results suggest that intralesionally administered ATF1011 binds to the tumor cell membrane and activates T cells specific for this carrier lectin in situ, which results in the augmented induction of systemic antitumor immunity. PMID:3496156

  19. Spontaneous and radiation induced cell death in HeLa S3 human carcinoma

    International Nuclear Information System (INIS)

    Radiation biologists have classified radiation-induced cell death based on cell proliferative capacity to either mitotic or interphase death. Cytologists have revealed two morphologically and biochemically diverse forms of cell death, apoptosis and necrosis. While the knowledge of the former is already well exploited by radiologists, cell susceptibility to apoptosis and necrosis is still under investigation. We studied characteristics of spontaneous cell death, and dose dependence and time course of radiation-induced cell death of human uterine cervix epitheloid carcinoma HeLaS3 in culture. Cells were irradiated with 2-40 Gy of γ-rays. The effect on growth, viability, morphology and genomic DNA structure were followed 24-72 h after irradiation. Cell viability was evaluated by trypan-blue exclusion assay and cell morphology by in situ DNA staining with propidium iodide. Cell genomic DNA fragmentation pattern was determined by electrophoresis on 2% agarose gels. At all cell densities 25-35% cells were PI positive and their DNA was fragmented to a high molecular size (≥20 kbp), but the internucleosomal ladder was not observed. A significant decrease in viability to 33% was observed 72 h post 40 Gy irradiation. It corresponded to 55% of PI positive cells. A smear of smaller DNA fragments (0.1-1 kbp), 24 h after 10-20 Gy irradiation was considered as proof that the dominant form of radiation-induced cell death was necrosis. It was concluded that the dominant form of radiation-induced cell death in HeLaS3 population was necrosis and the radiation dose which caused 50% of cell death after 72 h (termed ND50) was between 30-40 Gy. (author)

  20. Antigen-specific and non-specific CD4+ T cell recruitment and proliferation during influenza infection

    International Nuclear Information System (INIS)

    To track epitope-specific CD4+ T cells at a single-cell level during influenza infection, the MHC class II-restricted OVA323-339 epitope was engineered into the neuraminidase stalk of influenza/A/WSN, creating a surrogate viral antigen. The recombinant virus, influenza A/WSN/OVAII, replicated well, was cleared normally, and stimulated both wild-type and DO11.10 or OT-II TCR transgenic OVA-specific CD4+ T cells. OVA-specific CD4 T cells proliferated during infection only when the OVA epitope was present. However, previously primed (but not naive) transgenic CD4+ T cells were recruited to the infected lung both in the presence and absence of the OVA323-339 epitope. These data show that, when primed, CD4+ T cells may traffic to the lung in the absence of antigen, but do not proliferate. These results also document a useful tool for the study of CD4 T cells in influenza infection

  1. Chromosomal changes in cultured human epithelial cells transformed by low- and high-LET radiation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Tracy Chui-hsu; Craise, L.M; Prioleau, J.C.; Stampfer, M.R.; Rhim, J.S.

    1990-11-01

    For a better assessment of radiation risk in space, an understanding of the responses of human cells, especially the epithelial cells, to low- and high-LET radiation is essential. In our laboratory, we have successfully developed techniques to study the neoplastic transformation of two human epithelial cell systems by ionizing radiation. These cell systems are human mammary epithelial cells (H184B5) and human epidermal keratinocytes (HEK). Both cell lines are immortal, anchorage dependent for growth, and nontumorigenic in athymic nude nice. Neoplastic transformation was achieved by irradiation cells successively. Our results showed that radiogenic cell transformation is a multistep process and that a single exposure of ionizing radiation can cause only one step of transformation. It requires, therefore, multihits to make human epithelial cells fully tumorigenic. Using a simple karyotyping method, we did chromosome analysis with cells cloned at various stages of transformation. We found no consistent large terminal deletion of chromosomes in radiation-induced transformants. Some changes of total number of chromosomes, however, were observed in the transformed cells. These transformants provide an unique opportunity for further genetic studies at a molecular level. 15 refs., 9 figs., 2 tabs.

  2. Chromosomal changes in cultured human epithelial cells transformed by low- and high-LET radiation

    Science.gov (United States)

    Craise, L. M.; Prioleau, J. C.; Stampfer, M. R.; Rhim, J. S.; Yang, TC-H (Principal Investigator)

    1992-01-01

    For a better assessment of radiation risk in space, an understanding of the responses of human cells, especially the epithelial cells, to low- and high-LET radiation is essential. In our laboratory, we have successfully developed techniques to study the neoplastic transformation of two human epithelial cell systems by ionizing radiation. These cell systems are human mammary epithelial cells (H184B5) and human epidermal keratinocytes (HEK). Both cell lines are immortal, anchorage dependent for growth, and nontumorigenic in athymic nude mice. Neoplastic transformation was achieved by irradiating cells successively. Our results showed that radiogenic cell transformation is a multistep process and that a single exposure of ionizing radiation can cause only one step of transformation. It requires, therefore, multihits to make human epithelial cells fully tumorigenic. Using a simple karyotyping method, we did chromosome analysis with cells cloned at various stages of transformation. We found no consistent large terminal deletion of chromosomes in radiation-induced transformants. Some changes of total number of chromosomes, however, were observed in the transformed cells. These transformants provide an unique opportunity for further genetic studies at a molecular level.

  3. Cell type-specific responses of peripheral blood mononuclear cells to silver nanoparticles.

    Science.gov (United States)

    Greulich, C; Diendorf, J; Gessmann, J; Simon, T; Habijan, T; Eggeler, G; Schildhauer, T A; Epple, M; Köller, M

    2011-09-01

    Silver nanoparticles (Ag-NP) are increasingly used in biomedical applications because of their remarkable antimicrobial activity. In biomedicine, Ag-NP are coated onto or embedded in wound dressings, surgical instruments and bone substitute biomaterials, such as silver-containing calcium phosphate cements. Free Ag-NP and silver ions are released from these coatings or after the degradation of a biomaterial, and may come into close contact with blood cells. Despite the widespread use of Ag-NP as an antimicrobial agent, there is a serious lack of information on the biological effects of Ag-NP on human blood cells. In this study, the uptake of Ag-NP by peripheral monocytes and lymphocytes (T-cells) was analyzed, and the influence of nanosilver on cell biological functions (proliferation, the expression of adhesion molecules, cytokine release and the generation of reactive oxygen species) was studied. After cell culture in the presence of monodispersed Ag-NP (5-30μgml(-1) silver concentration), agglomerates of nanoparticles were detected within monocytes (CD14+) but not in T-cells (CD3+) by light microscopy, flow cytometry and combined focused ion beam/scanning electron microscopy. The uptake rate of nanoparticles was concentration dependent, and the silver agglomerates were typically found in the cytoplasm. Furthermore, a concentration-dependent activation (e.g. an increased expression of adhesion molecule CD54) of monocytes at Ag-NP concentrations of 10-15μgml(-1) was observed, and cytotoxicity of Ag-NP-treated monocytes was observed at Ag-NP levels of 25μgml(-1) and higher. However, no modulation of T-cell proliferation was observed in the presence of Ag-NP. Taken together, our results provide the first evidence for a cell-type-specific uptake of Ag-NP by peripheral blood mononuclear cells (PBMC) and the resultant cellular responses after exposure.

  4. Impact of Neoadjuvant Radiation on Survival in Stage III Non-Small-Cell Lung Cancer

    International Nuclear Information System (INIS)

    Purpose: The role of surgery in Stage III non-small-cell lung cancer (NSCLC) is controversial. This study was undertaken to assess the impact of neoadjuvant radiation therapy for Stage III NSCLC. Methods and Materials: This was a retrospective study from the Surveillance, Epidemiology, and End Results (SEER) database that included patients who were 18 years and older with NSCLC classified as Stage III and who underwent definitive therapy from 1988 to 2004. Patients were characterized by type of treatment received. Survival functions were estimated by the Kaplan-Meier method, and Cox regression model was used to analyze trends in overall (OS) and cause-specific survival (CSS). Results: A total of 48,131 patients were selected, with a median follow-up of 10 months (range, 0-203 months). By type of treatment, the 3-year OS was 10% with radiation therapy (RT), 37% with surgery (S), 34% with surgery and postoperative radiation (S-RT), and 45% with neoadjuvant radiation followed by surgery (Neo-RT) (p = 0.0001). Multivariable Cox model identified sex, race, laterality, T stage, N stage, and type of treatment as factors affecting survival. Estimated hazard ratios (HR) adjusted for other variables in regression model showed the types of treatment: S (HR, 1.3; 95% confidence interval [CI], 1.2-1.4), S-RT (HR, 1.2; 95% CI, 1.1-1.3), and RT (HR, 2.3; 95% CI, 2.15-2.53) were associated with significantly worse overall survival when compared with Neo-RT (p = 0.0001). Conclusion: This population based study demonstrates that patients with Stage III NSCLC receiving Neo-RT had significantly improved overall survival when compared with other treatment groups.

  5. Protocol of specific health monitoring: ionizing radiation, 11 years later; Protocolo de vigilancia sanitaria especifica: radiaciones ionizantes, 11 anos despues

    Energy Technology Data Exchange (ETDEWEB)

    Castillejo Puertas, F. M.

    2016-08-01

    Since the approval on November 11{sup t}h 2003 of the Protocol of Specific Health Monitoring for Workers Exposed to Ionizing Radiation a study has been carried out to discover its effectiveness. These areas were examined: the daily practice od accupational medicine and, in particular, its specific task in the application of the different clinical/labour criteria for workers exposed to ionizing radiation or at risk of radioactive contamination; the degree of its uses as well as the updates and improvements. For that purpose, a descriptive bibliographic revision has been used for the last 11 years. The results revealed the lack of updates of the Protocol as well as the few usable objective criteria, when the clinical/labour aptitudes are reflected upon. (Author)

  6. Distal airway epithelial progenitor cells are radiosensitive to High-LET radiation

    Science.gov (United States)

    McConnell, Alicia M.; Konda, Bindu; Kirsch, David G.; Stripp, Barry R.

    2016-01-01

    Exposure to high-linear energy transfer (LET) radiation occurs in a variety of situations, including charged particle radiotherapy, radiological accidents, and space travel. However, the extent of normal tissue injury in the lungs following high-LET radiation exposure is unknown. Here we show that exposure to high-LET radiation led to a prolonged loss of in vitro colony forming ability by airway epithelial progenitor cells. Furthermore, exposure to high-LET radiation induced clonal expansion of a subset of progenitor cells in the distal airway epithelium. Clonal expansion following high-LET radiation exposure was correlated with elevated progenitor cell apoptosis, persistent γ-H2AX foci, and defects in mitotic progression of distal airway progenitors. We discovered that the effects of high-LET radiation exposure on progenitor cells occur in a p53-dependent manner. These data show that high-LET radiation depletes the distal airway progenitor pool by inducing cell death and loss of progenitor function, leading to clonal expansion. Importantly, high-LET radiation induces greater long-term damage to normal lung tissue than the relative equivalent dose of low-LET γ-rays, which has implications in therapeutic development and risk assessment. PMID:27659946

  7. Enhanced cell-permeant Cre protein for site-specific recombination in cultured cells

    Directory of Open Access Journals (Sweden)

    Ruley H Earl

    2004-10-01

    Full Text Available Abstract Background Cell-permeant Cre DNA site-specific recombinases provide an easily controlled means to regulate gene structure and function in living cells. Since recombination provides a stable and unambiguous record of protein uptake, the enzyme may also be used for quantitative studies of cis- and trans-acting factors that influence the delivery of proteins into cells. Results In the present study, 11 recombinant fusion proteins were analyzed to characterize sequences and conditions that affect protein uptake and/or activity and to develop more active cell-permeant enzymes. We report that the native enzyme has a low, but intrinsic ability to enter cells. The most active Cre proteins tested contained either an N-terminal 6xHis tag and a nuclear localization sequence from SV40 large T antigen (HNC or the HIV Tat transduction sequence and a C-terminal 6xHis tag (TCH6. The NLS and 6xHis elements separately enhanced the delivery of the HNC protein into cells; moreover, transduction sequences from fibroblast growth factor 4, HIV Tat or consisting of the (KFF3K sequence were not required for efficient protein transduction and adversely affected enzyme solubility. Transduction of the HNC protein required 10 to 15 min for half-maximum uptake, was greatly decreased at 4°C and was inhibited by serum. Efficient recombination was observed in all cell types tested (a T-cell line, NIH3T3, Cos7, murine ES cells, and primary splenocytes, and did not require localization of the enzyme to the nucleus. Conclusions The effects of different sequences on the delivery and/or activity of Cre in cultured cells could not be predicted in advance. Consequently, the process of developing more active cell-permeant recombinases was largely empirical. The HNC protein, with an excellent combination of activity, solubility and yield, will enhance the use of cell-permeant Cre proteins to regulate gene structure and function in living cells.

  8. Radiation results in IL-8 mediated intercellular signaling that increases adhesion between monocytic cells and aortic endothelium

    Science.gov (United States)

    Kucik, Dennis; Babitz, Stephen; Dunaway, Chad; Steele, Chad

    cells (HAECs) in vitro under conditions that mimic the shear stress in the bloodstream. For both heavy ions and x-rays, these adhesiveness changes are independent of adhesion molecule expression levels, but are chemokine dependent. Here we identify the specific endothelial chemokine responsible for this radiation-induced adhesiveness. X-irradiation increased IL-8 secretion almost 5-fold, while having little or no effect on expression of 15 other chemokines. Adhesiveness was then assayed under physiological shear stress using a flow chamber adhesion assay. Radiation significantly increased endothelial adhesiveness. The radiation-induced adhesiveness was specifically blocked by anti-IL-8 antibody, with no effect on baseline, radiation-independent adhesion. Addition of recombinant human IL-8 to un-irradiated HAECs was sufficient to increase adhesion to the same level as x-rays. Therefore, radiation-induced IL-8 signaling is both necessary and sufficient for radiation effects on aortic endothelial adhesiveness. This IL-8 induced adhesiveness may explain, at least in part, the mechanism by which radiation accelerates development of atherosclerosis. A better understanding of this mechanism can provide the basis for future countermeasure development.

  9. Generation of Human Lens Epithelial-Like Cells From Patient-Specific Induced Pluripotent Stem Cells.

    Science.gov (United States)

    Li, Dan; Qiu, Xiaodi; Yang, Jin; Liu, Tianjin; Luo, Yi; Lu, Yi

    2016-12-01

    Cataractogenesis begins from the dynamic lens epithelial cells (LECs) and adjacent fiber cells. LECs derived from cell lines cannot maintain the crystalline expression as the primary LECs. The current study aimed to efficiently generate large numbers of human LECs from patient-specific induced pluripotent stem cells (iPSCs). Anterior lens capsules were collected from cataract surgery and were used to culture primary hLECs. iPSCs were induced from these primary hLECs by lentiviral transduction of Oct4, Sox2, Klf4, and c-Myc. Then, the generated iPSCs were re-differentiated into hLECs by the 3-step addition of defined factor combinations (Noggin, BMP4/7, bFGF, and EGF) modified from an established method. During the re-differentiation process, colonies of interest were isolated using a glass picking tool and cloning cylinders based on the colony morphology. After two steps of isolation, populations of LEC-like cells (LLCs) were generated and identified by the expression of lens marker genes by qPCR, western blot and immunofluorescence staining. The study introduced a modified protocol to isolate LLCs from iPSCs by defined factors in a short time frame. This technique could be useful for mechanistic studies of lens-related diseases. J. Cell. Physiol. 231: 2555-2562, 2016. © 2016 Wiley Periodicals, Inc. PMID:26991066

  10. Mesenchymal Stromal Cells and Tissue-Specific Progenitor Cells: Their Role in Tissue Homeostasis

    Directory of Open Access Journals (Sweden)

    Aleksandra Klimczak

    2016-01-01

    Full Text Available Multipotent mesenchymal stromal/stem cells (MSCs reside in many human organs and comprise heterogeneous population of cells with self-renewal ability. These cells can be isolated from different tissues, and their morphology, immunophenotype, and differentiation potential are dependent on their tissue of origin. Each organ contains specific population of stromal cells which maintain regeneration process of the tissue where they reside, but some of them have much more wide plasticity and differentiate into multiple cells lineage. MSCs isolated from adult human tissues are ideal candidates for tissue regeneration and tissue engineering. However, MSCs do not only contribute to structurally tissue repair but also MSC possess strong immunomodulatory and anti-inflammatory properties and may influence in tissue repair by modulation of local environment. This paper is presenting an overview of the current knowledge of biology of tissue-resident mesenchymal stromal and progenitor cells (originated from bone marrow, liver, skeletal muscle, skin, heart, and lung associated with tissue regeneration and tissue homeostasis.

  11. Cell type-specific properties and environment shape tissue specificity of cancer genes.

    Science.gov (United States)

    Schaefer, Martin H; Serrano, Luis

    2016-02-09

    One of the biggest mysteries in cancer research remains why mutations in certain genes cause cancer only at specific sites in the human body. The poor correlation between the expression level of a cancer gene and the tissues in which it causes malignant transformations raises the question of which factors determine the tissue-specific effects of a mutation. Here, we explore why some cancer genes are associated only with few different cancer types (i.e., are specific), while others are found mutated in a large number of different types of cancer (i.e., are general). We do so by contrasting cellular functions of specific-cancer genes with those of general ones to identify properties that determine where in the body a gene mutation is causing malignant transformations. We identified different groups of cancer genes that did not behave as expected (i.e., DNA repair genes being tissue specific, immune response genes showing a bimodal specificity function or strong association of generally expressed genes to particular cancers). Analysis of these three groups demonstrates the importance of environmental impact for understanding why certain cancer genes are only involved in the development of some cancer types but are rarely found mutated in other types of cancer.

  12. A dramatic effect of oxygen on protection of human cells against γ-radiation by lycopene.

    Science.gov (United States)

    Boehm, Fritz; Edge, Ruth; Truscott, Terence George; Witt, Christian

    2016-04-01

    Reducing radiation damage is important and dietary antioxidants that can protect cells from such damage are of value. Dietary lycopene, a carotenoid found in tomatoes, protects human lymphoid cell membranes from damage by γ-radiation. We report that such protective effects are remarkably reduced as the oxygen concentration increases - near zero at 100% oxygen from fivefold protection at 20% oxygen and, dramatically, from 50-fold protection at 0% oxygen. Such huge differences imply that under higher oxygen concentrations lycopene could lead to improved cancer therapy using γ-radiation. The cells are not efficiently protected from the superoxide radical by lycopene. Noncellular studies suggest molecular mechanisms for the oxygen effect. PMID:26991327

  13. Medium-mediated DNA repair response after ionizing radiation is correlated with the increase of specific cytokines in human fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Dieriks, Birger, E-mail: patrick.vanoostveldt@ugent.be [Laboratory for Biochemistry and Molecular Cytology, Department of Molecular Biotechnology, Ghent University, Coupure Links 653, 9000 Gent (Belgium); De Vos, Winnok H. [Laboratory for Biochemistry and Molecular Cytology, Department of Molecular Biotechnology, Ghent University, Coupure Links 653, 9000 Gent (Belgium); Derradji, Hanane; Baatout, Sarah [Laboratory Molecular and Cellular Biology, Radiobiology Unit, Belgian Nuclear Research Center, SCK CEN, Boeretang 200, 2400 Mol (Belgium); Van Oostveldt, Patrick [Laboratory for Biochemistry and Molecular Cytology, Department of Molecular Biotechnology, Ghent University, Coupure Links 653, 9000 Gent (Belgium)

    2010-05-01

    Radiation induced bystander effects, either protective or adverse, have been identified in a variety of cells and for different endpoints. They are thought to arise from communication between cells through direct cell-cell contacts and via transmissible molecules secreted into the medium by targeted cells. We have investigated medium-mediated damage response in human dermal fibroblasts (HDF) after exposure to ionizing irradiation. We show that HDF experience an elevated level of double stranded DNA damage repair response when incubated with conditioned growth medium of irradiated cells. The magnitude of this response is much lower than observed for directly irradiated cells and is proportional to the radiation dose, as is its persistence across time. Since secretion of cytokines is one of the possible pathways linking targeted and non-targeted cells a multiplex analysis was performed. Four cytokines - IL6, IL8, MCP-1 and RANTES - were identified in the growth medium of irradiated cells after exposure to X-rays (2 Gy). These cytokines were significantly upregulated and each cytokine showed differential upregulation kinetics. Finally we performed a functional analysis to see if IL6 and MCP-1 could induce {gamma}H2AX foci formation. IL6 caused a significant increase in spot occupancy compared to controls. Although only indicative MCP-1 appears to have the opposite effect as it caused a drop in spot occupancy. The combined addition of these two cytokines produced no significant response was observed. Both IL6 and MCP-1 have an effect on the {gamma}H2AX spot occupancy possibly linking these cytokines to the bystander response.

  14. Reduction of radiation-induced damage to salivary gland by bone marrow derived stem cells

    International Nuclear Information System (INIS)

    Irradiation of the salivary glands can result in severe side effects that reduce the patient's quality of life. Late damage to the salivary glands is mainly caused by exhaustion of the tissue's stem cells. Post-irradiation replacement of salivary gland stem cells with healthy donor stem cells may reduce complications. Bone marrow derived stem cells (BMSC) have been show to be multipotent and engraft in many tissue after injury. In this study we assessed the potential of BMSC to reduce irradiation-induced salivary gland damage. The salivary glands of wild type C57Bl/6 mice were locally irradiated with 20 Gy. Thirty days later, BMSC from transgenic eGFP+ C57Bl/6 mice were transplanted by i.v. injection or by direct injection into the salivary glands. In addition, animals were transplanted with eGFP + bone marrow after 9.5 Gy TBI excluding the salivary glands. Subsequently, the animals were locally irradiated to the salivary gland with 20 Gy. Thirty days later i.v. G-CSF mobilised eGFP + bone marrow derived stem cells to the peripheral blood. Again thirty days after mobilisation, the salivary gland were harvested. eGFP + cells were detected by confocal laser fluorescence scanning microscopy and flow cytometry and H and E histology was performed. eGFP + cells were detected in the salivary gland after all protocols. The number of eGFP + cells in irradiated salivary glands was highest in animals treated with G-CSF. Intraglandular transplantation, in contrast, was successful only in 1 out of 8 attempts. Immuno-histochemistry using a-SM-actin antibodies showed the close vicinity of actin and eGFP within the cells, demonstrating the occurrence of BMSC derived myoepithelial cells in irradiated salivary gland. Further, cell-type specific antibodies will reveal the nature of all eGFP + cells. H and E histology revealed improved gland morphology in animals treated with G-CSF after irradiation when compared to the non-treated animals. These preliminary results indicate that bone

  15. Handheld X-ray Fluorescence Spectrometers: Radiation Exposure Risks of Matrix-Specific Measurement Scenarios.

    Science.gov (United States)

    Rouillon, Marek; Kristensen, Louise J; Gore, Damian B

    2015-07-01

    This study investigates X-ray intensity and dispersion around handheld X-ray fluorescence (XRF) instruments during the measurement of a range of sample matrices to establish radiation exposure risk during operation. Four handheld XRF instruments representing three manufacturers were used on four smooth, flat-lying materials of contrasting matrix composition. Dose rates were measured at 10, 20, 30, and 40 cm intervals every 30° around the instrument at 0 and 45° from the horizontal, as well as vertically from the instrument screen. The analysis of polyethylene recorded dose rates 156 times higher (on average) than steel measurements and 34 times higher than both quartz sand and quartz sandstone. A worst-case exposure scenario was assumed where a user analyses a polyethylene material at arms reach for 1 h each working day for one year. This scenario resulted in an effective body dose of 73.5 μSv, equivalent to three to four chest X-rays (20 μSv) a year, 20 times lower than the average annual background radiation exposure in Australia and well below the annual exposure limit of 1 mSv for non-radiation workers. This study finds the advantages of using handheld XRF spectrometers far outweighs the risk of low radiation exposure linked to X-ray scattering from samples. PMID:26037330

  16. Cytotoxicity and mutagenicity of opthalmic solution preservatives and UVA radiation in L5178Y cells

    International Nuclear Information System (INIS)

    Four preservatives used in ophthalmic solutions were tested for toxic and mutagenic potential in mouse lymphoma cells with and without exposure of cells to ultraviolet A (UVA) radiation. The preservatives tested were benzalkonium chloride (BAK), chlorhexidine, thimerosal and ethylenediaminetetraacetic acid (EDTA). Cell survival and mutagenesis were measured using the L5178Y mouse lymphoma (TK+/-) system. Cells were exposed to varying amounts of preservatives for 1 h at 370C, and aliquots irradiated with UVA radiation (during exposure to preservative). Cells were then assayed for survival, and mutagenesis at the thymidine kinase (TK) locus. In concentrations commonly found in ophthalmic solutions, BAK, chlorhexidine, and thimerosal were toxic to cells, and thimerosal was slightly mutagenic. When cells were exposed to preservative and UVA radiation, chlorhexidine was mutagenic and the mutagenic activity of thimerosal was enhanced. (author)

  17. Cytotoxicity and mutagenicity of opthalmic solution preservatives and UVA radiation in L5178Y cells

    Energy Technology Data Exchange (ETDEWEB)

    Withrow, T.J.; Brown, N.T.; Hitchins, V.M.; Strickland, A.G. (Food and Drug Administration, Rockville, MD (USA). Center for Devices and Radiological Health)

    1989-09-01

    Four preservatives used in ophthalmic solutions were tested for toxic and mutagenic potential in mouse lymphoma cells with and without exposure of cells to ultraviolet A (UVA) radiation. The preservatives tested were benzalkonium chloride (BAK), chlorhexidine, thimerosal and ethylenediaminetetraacetic acid (EDTA). Cell survival and mutagenesis were measured using the L5178Y mouse lymphoma (TK{sup +/-}) system. Cells were exposed to varying amounts of preservatives for 1 h at 37{sup 0}C, and aliquots irradiated with UVA radiation (during exposure to preservative). Cells were then assayed for survival, and mutagenesis at the thymidine kinase (TK) locus. In concentrations commonly found in ophthalmic solutions, BAK, chlorhexidine, and thimerosal were toxic to cells, and thimerosal was slightly mutagenic. When cells were exposed to preservative and UVA radiation, chlorhexidine was mutagenic and the mutagenic activity of thimerosal was enhanced. (author).

  18. HLA-DP specific responses in allogeneic stem cell transplantation

    NARCIS (Netherlands)

    Rutten, Caroline Elisabeth

    2013-01-01

    Clinical studies demonstrated that HLA-DPB1 mismatched stem cell transplantation (SCT) is associated with a decreased risk of disease relapse and an increased risk of graft versus host disease (GVHD) compared to HLA-DPB1 matched SCT. In T-cell depleted SCT, mismatching of HLA-DPB1 was not associated

  19. Electro pulse mediated enhancement of radiation response of murine cancer cells

    International Nuclear Information System (INIS)

    Full text: Radiotherapy is an important modality of cancer treatment but most often clinicians face some limitations. The major problems in cancer treatment are the radioresistance and chemoresistance of cancer cells which poses challenge to researchers and clinicians. To overcome these problems, a search for achieving the improved treatment of cancer is highly warranted. Electroporation is a biophysical technique that involves transient increase in cell membrane permeability by application of high voltage pulses of short duration. In recent years, cell membrane has been considered as a common target for ionizing radiation and electroporation. In our laboratory, we have investigated the combined treatment of gamma radiation and electric pulses to cancer cells both in vivo and in vitro. Experiments have been conducted in vitro using Ehlrich Ascites carcinoma cells with 60Co gamma irradiation and electric pulses. Results have shown significantly enhanced cytotoxicity of cells on combined treatment with radiation and electroporation. In vivo studies have been carried out using murine fibrosarcoma as a model system. Mice were segregated into following treatment groups: Control, radiation, electroporation, and radiation plus electroporation. Studies on tumor growth kinetics indicated a significant tumor growth delay when the transplanted tumor was treated with the a radiation followed by electroporation. It is suggested that optimization of parameters of electroporation and radiation may prove a powerful treatment modality for cancer in clinic

  20. Radiation resistance of thin-film solar cells for space photovoltaic power

    Science.gov (United States)

    Woodyard, James R.; Landis, Geoffrey A.

    1991-01-01

    Copper indium diselenide, cadmium telluride, and amorphous silicon alloy solar cells have achieved noteworthy performance and are currently being studied for space power applications. Cadmium sulfide cells had been the subject of much effort but are no longer considered for space applications. A review is presented of what is known about the radiation degradation of thin film solar cells in space. Experimental cadmium telluride and amorphous silicon alloy cells are reviewed. Damage mechanisms and radiation induced defect generation and passivation in the amorphous silicon alloy cell are discussed in detail due to the greater amount of experimental data available.

  1. The Los Alamos dynamic radiation environment assimilation model (DREAM) for space weather specification and forecasting

    Energy Technology Data Exchange (ETDEWEB)

    Reeves, Geoffrey D [Los Alamos National Laboratory; Friedel, Reiner H W [Los Alamos National Laboratory; Chen, Yue [Los Alamos National Laboratory; Koller, Josef [Los Alamos National Laboratory; Henderson, Michael G [Los Alamos National Laboratory

    2008-01-01

    The Dynamic Radiation Environment Assimilation Model (DREAM) was developed at Los Alamos National Laboratory to assess, quantify, and predict the hazards from the natural space environment and the anthropogenic environment produced by high altitude nuclear explosions (HANE). DREAM was initially developed as a basic research activity to understand and predict the dynamics of the Earth's Van Allen radiation belts. It uses Kalman filter techniques to assimilate data from space environment instruments with a physics-based model of the radiation belts. DREAM can assimilate data from a variety of types of instruments and data with various levels of resolution and fidelity by assigning appropriate uncertainties to the observations. Data from any spacecraft orbit can be assimilated but DREAM was designed to function with as few as two spacecraft inputs: one from geosynchronous orbit and one from GPS orbit. With those inputs, DREAM can be used to predict the environment at any satellite in any orbit whether space environment data are available in those orbits or not. Even with very limited data input and relatively simple physics models, DREAM specifies the space environment in the radiation belts to a high level of accuracy. DREAM has been extensively tested and evaluated as we transition from research to operations. We report here on one set of test results in which we predict the environment in a highly-elliptical polar orbit. We also discuss long-duration reanalysis for spacecraft design, using DREAM for real-time operations, and prospects for 1-week forecasts of the radiation belt environment.

  2. Hypofractionated radiation therapy for the treatment of feline facial squamous cell carcinoma

    International Nuclear Information System (INIS)

    The efficacy of hypofractionated radiation protocol for feline facial squamous cell carcinoma was evaluated. Hypofractionated radiation therapy was applied to five cats showing single or multiple facial squamous cell carcinomas, in a total of ten histologically confirmed neoplastic lesions. Of the lesions, two were staged as T1, four as T2, two as T3, and two as T4. The animals were submitted to four radiation fractions from 7.6 to 10 grays each, with one week intervals. The equipment was a linear accelerator with electrons beam. The cats were evaluated weekly during the treatment and 30 and 60 days after the end of the radiation therapy. In this study, 40% of the lesions had complete remission, 40% partial remission, and 20% did not respond to the treatment. Response rates were lower as compared to other protocols previously used. However, hypofractionated radiation protocol was considered safe for feline facial squamous cell carcinoma. (author)

  3. Clustered DNA damages induced in human hematopoietic cells by low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Ionizing radiation induces clusters of DNA damages-oxidized bases, abasic sites and strand breaks-on opposing strands within a few helical turns. Such damages have been postulated to be difficult to repair, as are double strand breaks (one type of cluster).We have shown that low doses of low and high linear energy transfer (LET) radiation induce such damage clusters in human cells. In human cells, double strand breaks (DSB) are about 30% of the total of complex damages, and the levels of DSBs and oxidized pyrimidine clusters are similar. The dose responsesfor cluster induction in cells can be described by a linear relationship, implying that even low doses of ionizing radiation can produce clustered damages. Studies are in progress to determine whether clusters can be produced by mechanisms other than ionizing radiation, as well as the levels of various cluster types formed by low and high LET radiation. (author)

  4. Anti-apoptotic peptides protect against radiation-induced cell death

    International Nuclear Information System (INIS)

    The risk of terrorist attacks utilizing either nuclear or radiological weapons has raised concerns about the current lack of effective radioprotectants. Here it is demonstrated that the BH4 peptide domain of the anti-apoptotic protein Bcl-xL can be delivered to cells by covalent attachment to the TAT peptide transduction domain (TAT-BH4) and provide protection in vitro and in vivo from radiation-induced apoptotic cell death. Isolated human lymphocytes treated with TAT-BH4 were protected against apoptosis following exposure to 15 Gy radiation. In mice exposed to 5 Gy radiation, TAT-BH4 treatment protected splenocytes and thymocytes from radiation-induced apoptotic cell death. Most importantly, in vivo radiation protection was observed in mice whether TAT-BH4 treatment was given prior to or after irradiation. Thus, by targeting steps within the apoptosis signaling pathway it is possible to develop post-exposure treatments to protect radio-sensitive tissues

  5. Protein disulphide isomerase as a target for nanoparticle-mediated sensitisation of cancer cells to radiation

    OpenAIRE

    Taggart, L E; McMahon, S. J.; Butterworth, K T; Currell, F. J.; Schettino, G; Prise, K. M.

    2016-01-01

    Radiation resistance and toxicity in normal tissues are limiting factors in the efficacy of radiotherapy. Gold nanoparticles (GNPs) have been shown to be effective at enhancing radiation-induced cell death, and were initially proposed to physically enhance the radiation dose deposited. However, biological responses of GNP radiosensitization based on physical assumptions alone are not predictive of radiosensitisation and therefore there is a fundamental research need to determine biological me...

  6. Metabolic response of lung cancer cells to radiation in a paper-based 3D cell culture system.

    Science.gov (United States)

    Simon, Karen A; Mosadegh, Bobak; Minn, Kyaw Thu; Lockett, Matthew R; Mohammady, Marym R; Boucher, Diane M; Hall, Amy B; Hillier, Shawn M; Udagawa, Taturo; Eustace, Brenda K; Whitesides, George M

    2016-07-01

    This work demonstrates the application of a 3D culture system-Cells-in-Gels-in-Paper (CiGiP)-in evaluating the metabolic response of lung cancer cells to ionizing radiation. The 3D tissue-like construct-prepared by stacking multiple sheets of paper containing cell-embedded hydrogels-generates a gradient of oxygen and nutrients that decreases monotonically in the stack. Separating the layers of the stack after exposure enabled analysis of the cellular response to radiation as a function of oxygen and nutrient availability; this availability is dictated by the distance between the cells and the source of oxygenated medium. As the distance between the cells and source of oxygenated media increased, cells show increased levels of hypoxia-inducible factor 1-alpha, decreased proliferation, and reduced sensitivity to ionizing radiation. Each of these cellular responses are characteristic of cancer cells observed in solid tumors. With this setup we were able to differentiate three isogenic variants of A549 cells based on their metabolic radiosensitivity; these three variants have known differences in their metastatic behavior in vivo. This system can, therefore, capture some aspects of radiosensitivity of populations of cancer cells related to mass-transport phenomenon, carry out systematic studies of radiation response in vitro that decouple effects from migration and proliferation of cells, and regulate the exposure of oxygen to subpopulations of cells in a tissue-like construct either before or after irradiation. PMID:27116031

  7. Protective effect of propolis on radiation-induced chromosomal damage on Chinese hamster ovary cells (CHO-K1)

    International Nuclear Information System (INIS)

    In the last years, particular interest has been given to investigations concerning natural, effective and nontoxic compounds with radioprotective capacity in concert with increasing utilization of different types of ionizing radiation for various applications. Among them, propolis, a resinous mixture of substances collected by honey bees (Apis mellifera) has been considered promising since it presents several advantageous characteristics, i.e., antiinflammatory, anticarcinogenic, antimicrobial and free radical scavenging action. It is, therefore, a direct antioxidant that protects cells and organisms from the adverse effects of ionizing radiation. These relevant biological activities are mainly mediated by the flavonoids, present at relatively high concentrations in the propolis. Considering that the chemical composition and, consequently, the biological activity of propolis is variable according to the environmental plant ecology, the present study was conducted in order to evaluate the radioprotective capacity of Brazilian propolis, collected in the State of Rio Grande do Sul, against genotoxic damages induced by 60Co γ-radiation in Chinese hamster ovary cells (CHO-K1). for this purpose, micronucleus induction was analyzed concerning irreparable damage, specifically related to DNA double-strand breaks, that are potentially carcinogenic. CHO-K1 cells were submitted to different concentrations of propolis (3 - 33 μg/ml), 1 h before irradiation, with 1 Gy of γ radiation (0.722 Gy/min). The data obtained showed a decreasing tendency in the quantity of radioinduced damage on cells previously treated with propolis. The radioprotective effect was more prominent at higher propolis concentration. The treatment with propolis alone did not induce genotoxic effects on CHO-K1 cells. Beside that, the treatment with propolis, associated or not with radiation, did not influence the kinetics of cellular proliferation. (author)

  8. Reciprocal complementation of the tumoricidal effects of radiation and natural killer cells.

    Directory of Open Access Journals (Sweden)

    Kai-Lin Yang

    Full Text Available The tumor microenvironment is a key determinant for radio-responsiveness. Immune cells play an important role in shaping tumor microenvironments; however, there is limited understanding of how natural killer (NK cells can enhance radiation effects. This study aimed to assess the mechanism of reciprocal complementation of radiation and NK cells on tumor killing. Various tumor cell lines were co-cultured with human primary NK cells or NK cell line (NK-92 for short periods and then exposed to irradiation. Cell proliferation, apoptosis and transwell assays were performed to assess apoptotic efficacy and cell viability. Western blot analysis and immunoprecipitation methods were used to determine XIAP (X-linked inhibitor of apoptosis protein and Smac (second mitochondria-derived activator of caspase expression and interaction in tumor cells. Co-culture did not induce apoptosis in tumor cells, but a time- and dose-dependent enhancing effect was found when co-cultured cells were irradiated. A key role for caspase activation via perforin/granzyme B (Grz B after cell-cell contact was determined, as the primary radiation enhancing effect. The efficacy of NK cell killing was attenuated by upregulation of XIAP to bind caspase-3 in tumor cells to escape apoptosis. Knockdown of XIAP effectively potentiated NK cell-mediated apoptosis. Radiation induced Smac released from mitochondria and neutralized XIAP and therefore increased the NK killing. Our findings suggest NK cells in tumor microenvironment have direct radiosensitization effect through Grz B injection while radiation enhances NK cytotoxicity through triggering Smac release.

  9. Cells determine cell density using a small protein bound to a unique tissue-specific phospholipid

    Directory of Open Access Journals (Sweden)

    Christopher J. Petzold

    2013-10-01

    Full Text Available Cell density is the critical parameter controlling tendon morphogenesis. Knowing its neighbors allows a cell to regulate correctly its proliferation and collagen production. A missing link to understanding this process is a molecular description of the sensing mechanism. Previously, this mechanism was shown in cell culture to rely on a diffusible factor (SNZR [sensor] with an affinity for the cell layer. This led to purifying conditioned medium over 4 columns and analyzing the final column fractions for band intensity on SDS gels versus biological activity – a 16 kD band strongly correlated between assays. N-terminal sequencing – EPLAVVDL – identified a large gene (424 AA, extremely conserved between chicken and human. In this paper we probe whether this is the correct gene. Can the predicted large protein be cleaved to a smaller protein? EPLAVVDL occurs towards the C-terminus and cleavage would create a small 94 AA protein. This protein would run at ∼10 kD, so what modifications or cofactor binding accounts for its running at 16 kD on SDS gels? This protein has no prominent hydrophobic regions, so can it be secreted? To validate its role, the chicken cDNA for this gene was tagged with myc and his and transfected into a human osteosarcoma cell line (U2OS. U2OS cells expressed the gene but not passively: differentiating into structures resembling spongy bone and expressing alkaline phosphatase, an early bone marker. Intracellularly, two bands were observed by Western blotting: the full length protein and a smaller form (26 kD. Outside the cell, a small band (28 kD was detected, although it was 40% larger than expected, as well as multiple larger bands. These larger forms could be converted to the predicted smaller protein (94 AA + tags by changing salt concentrations and ultrafiltering – releasing a cofactor to the filtrate while leaving a protein factor in the retentate. Using specific degradative enzymes and mass spectrometry, the

  10. Radiation induced cell loss in rat submandibular gland and its relation to gland function

    NARCIS (Netherlands)

    Zeilstra, LJW; Vissink, A; Konings, AWT; Coppes, RP

    2000-01-01

    Purpose: To understand early and late radiation-induced loss of function of the submandibular gland, changes in cell number were documented and correlated with data on gland function. Modulation of the radiation effect by sialogogues was used to investigate possible mechanisms of action. Materials a

  11. Exosomes Derived from Squamous Head and Neck Cancer Promote Cell Survival after Ionizing Radiation.

    Directory of Open Access Journals (Sweden)

    Lisa Mutschelknaus

    Full Text Available Exosomes are nanometer-sized extracellular vesicles that are believed to function as intercellular communicators. Here, we report that exosomes are able to modify the radiation response of the head and neck cancer cell lines BHY and FaDu. Exosomes were isolated from the conditioned medium of irradiated as well as non-irradiated head and neck cancer cells by serial centrifugation. Quantification using NanoSight technology indicated an increased exosome release from irradiated compared to non-irradiated cells 24 hours after treatment. To test whether the released exosomes influence the radiation response of other cells the exosomes were transferred to non-irradiated and irradiated recipient cells. We found an enhanced uptake of exosomes isolated from both irradiated and non-irradiated cells by irradiated recipient cells compared to non-irradiated recipient cells. Functional analyses by exosome transfer indicated that all exosomes (from non-irradiated and irradiated donor cells increase the proliferation of non-irradiated recipient cells and the survival of irradiated recipient cells. The survival-promoting effects are more pronounced when exosomes isolated from irradiated compared to non-irradiated donor cells are transferred. A possible mechanism for the increased survival after irradiation could be the increase in DNA double-strand break repair monitored at 6, 8 and 10 h after the transfer of exosomes isolated from irradiated cells. This is abrogated by the destabilization of the exosomes. Our results demonstrate that radiation influences both the abundance and action of exosomes on recipient cells. Exosomes transmit prosurvival effects by promoting the proliferation and radioresistance of head and neck cancer cells. Taken together, this study indicates a functional role of exosomes in the response of tumor cells to radiation exposure within a therapeutic dose range and encourages that exosomes are useful objects of study for a better

  12. Exosomes Derived from Squamous Head and Neck Cancer Promote Cell Survival after Ionizing Radiation.

    Science.gov (United States)

    Mutschelknaus, Lisa; Peters, Carsten; Winkler, Klaudia; Yentrapalli, Ramesh; Heider, Theresa; Atkinson, Michael John; Moertl, Simone

    2016-01-01

    Exosomes are nanometer-sized extracellular vesicles that are believed to function as intercellular communicators. Here, we report that exosomes are able to modify the radiation response of the head and neck cancer cell lines BHY and FaDu. Exosomes were isolated from the conditioned medium of irradiated as well as non-irradiated head and neck cancer cells by serial centrifugation. Quantification using NanoSight technology indicated an increased exosome release from irradiated compared to non-irradiated cells 24 hours after treatment. To test whether the released exosomes influence the radiation response of other cells the exosomes were transferred to non-irradiated and irradiated recipient cells. We found an enhanced uptake of exosomes isolated from both irradiated and non-irradiated cells by irradiated recipient cells compared to non-irradiated recipient cells. Functional analyses by exosome transfer indicated that all exosomes (from non-irradiated and irradiated donor cells) increase the proliferation of non-irradiated recipient cells and the survival of irradiated recipient cells. The survival-promoting effects are more pronounced when exosomes isolated from irradiated compared to non-irradiated donor cells are transferred. A possible mechanism for the increased survival after irradiation could be the increase in DNA double-strand break repair monitored at 6, 8 and 10 h after the transfer of exosomes isolated from irradiated cells. This is abrogated by the destabilization of the exosomes. Our results demonstrate that radiation influences both the abundance and action of exosomes on recipient cells. Exosomes transmit prosurvival effects by promoting the proliferation and radioresistance of head and neck cancer cells. Taken together, this study indicates a functional role of exosomes in the response of tumor cells to radiation exposure within a therapeutic dose range and encourages that exosomes are useful objects of study for a better understanding of tumor

  13. Target cell-specific modulation of neuronal activity by astrocytes

    OpenAIRE

    Kozlov, A. S.; Angulo, M. C.; Audinat, E.; Charpak, S

    2006-01-01

    Interaction between astrocytes and neurons enriches the behavior of brain circuits. By releasing glutamate and ATP, astrocytes can directly excite neurons and modulate synaptic transmission. In the rat olfactory bulb, we demonstrate that the release of GABA by astrocytes causes long-lasting and synchronous inhibition of mitral and granule cells. In addition, astrocytes release glutamate, leading to a selective activation of granule-cell NMDA receptors. Thus, by releasing excitatory and inhibi...

  14. Organotypic culture in three dimensions prevents radiation-induced transformation in human lung epithelial cells

    Science.gov (United States)

    El-Ashmawy, Mariam; Coquelin, Melissa; Luitel, Krishna; Batten, Kimberly; Shay, Jerry W.

    2016-08-01

    The effects of radiation in two-dimensional (2D) cell culture conditions may not recapitulate tissue responses as modeled in three-dimensional (3D) organotypic culture. In this study, we determined if the frequency of radiation-induced transformation and cancer progression differed in 3D compared to 2D culture. Telomerase immortalized human bronchial epithelial cells (HBECs) with shTP53 and mutant KRas expression were exposed to various types of radiation (gamma, +H, 56Fe) in either 2D or 3D culture. After irradiation, 3D structures were dissociated and passaged as a monolayer followed by measurement of transformation, cell growth and expression analysis. Cells irradiated in 3D produced significantly fewer and smaller colonies in soft agar than their 2D-irradiated counterparts (gamma P = 0.0004 +H P = 0.049 56Fe P culture conditions did not affect cell killing, the ability of cells to survive in a colony formation assay, and proliferation rates after radiation—implying there was no selection against cells in or dissociated from 3D conditions. However, DNA damage repair and apoptosis markers were increased in 2D cells compared to 3D cells after radiation. Ideally, expanding the utility of 3D culture will allow for a better understanding of the biological consequences of radiation exposure.

  15. The Effects of Fenugreek on Radiation Induced Toxicity for Human Blood T-Cells in Radiotherapy.

    Science.gov (United States)

    Tavakoli, Mohamed Bagher; Kiani, Ali; Roayaei, Mahnaz

    2015-01-01

    Many cellular damages either in normal or cancerous tissues are the outcome of molecular events affected by ionizing radiation. T-cells are the most important among immune system agents and are used for biological radiation dose measurement in recommended standard methods. The herbs with immune modulating properties may be useful to reduce the risk of the damages and subsequently the diseases. The T-cells as the most important immune cells being targeted for biological dosimetry of radiation. This study proposes a flowcytometric-method based on fluorescein isothiocyanate- and propidium iodide (PI)-labeled annexin-V to assess apoptosis in blood T-cells after irradiation in both presence and absence of fenugreek extract. T-cells peripheral blood lymphocyte isolated from blood samples of healthy individuals with no irradiated job background. The media of cultured cells was irradiated 1-h after the fenugreek extract was added. The number of apoptotic cells was assessed by annexin-V protocol and multicolor flowcytometry. An obvious variation in apoptotic cells number was observed in presence of fenugreek extract (>80%). The results suggest that fenugreek extract can potentiate the radiation induced apoptosis or radiation toxicity in blood T-cells (P < 0.05). PMID:26284174

  16. Cell-permeable intrinsic cellular inhibitors of apoptosis protect and rescue intestinal epithelial cells from radiation-induced cell death

    International Nuclear Information System (INIS)

    One of the important mechanisms for gastrointestinal (GI) injury following high-dose radiation exposure is apoptosis of epithelial cells. X-linked inhibitor of apoptosis (XIAP) and cellular IAP2 (cIAP2) are intrinsic cellular inhibitors of apoptosis. In order to study the effects of exogenously added IAPs on apoptosis in intestinal epithelial cells, we constructed bacterial expression plasmids containing genes of XIAP (full-length, BIR2 domain and BIR3-RING domain with and without mutations of auto-ubiquitylation sites) and cIAP2 proteins fused to a protein-transduction domain (PTD) derived from HIV-1 Tat protein (TAT) and purified these cell-permeable recombinant proteins. When the TAT-conjugated IAPs were added to rat intestinal epithelial cells IEC6, these proteins were effectively delivered into the cells and inhibited apoptosis, even when added after irradiation. Our results suggest that PTD-mediated delivery of IAPs may have clinical potential, not only for radioprotection but also for rescuing the GI system from radiation injuries. (author)

  17. Cell-permeable intrinsic cellular inhibitors of apoptosis protect and rescue intestinal epithelial cells from radiation-induced cell death.

    Science.gov (United States)

    Matsuzaki-Horibuchi, Shiori; Yasuda, Takeshi; Sakaguchi, Nagako; Yamaguchi, Yoshihiro; Akashi, Makoto

    2015-01-01

    One of the important mechanisms for gastrointestinal (GI) injury following high-dose radiation exposure is apoptosis of epithelial cells. X-linked inhibitor of apoptosis (XIAP) and cellular IAP2 (cIAP2) are intrinsic cellular inhibitors of apoptosis. In order to study the effects of exogenously added IAPs on apoptosis in intestinal epithelial cells, we constructed bacterial expression plasmids containing genes of XIAP (full-length, BIR2 domain and BIR3-RING domain with and without mutations of auto-ubiquitylation sites) and cIAP2 proteins fused to a protein-transduction domain (PTD) derived from HIV-1 Tat protein (TAT) and purified these cell-permeable recombinant proteins. When the TAT-conjugated IAPs were added to rat intestinal epithelial cells IEC6, these proteins were effectively delivered into the cells and inhibited apoptosis, even when added after irradiation. Our results suggest that PTD-mediated delivery of IAPs may have clinical potential, not only for radioprotection but also for rescuing the GI system from radiation injuries.

  18. Th Cell Gene Expression and Function in Response to Low Dose and Acute Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Daila S. Gridley, PhD

    2012-03-30

    FINAL TECHNICAL REPORT Supported by the Low Dose Radiation Research Program, Office of Science U.S. Department of Energy Grant No. DE-FG02-07ER64345 Project ID: 0012965 Award Register#: ER64345 Project Manager: Noelle F. Metting, Sc.D. Phone: 301-903-8309 Division SC-23.2 noelle.metting@science.doe.gov Submitted March 2012 To: https://www.osti.gov/elink/241.3.jsp Title: Th Cell Gene Expression and Function in Response to Low Dose and Acute Radiation PI: Daila S. Gridley, Ph.D. Human low dose radiation data have been derived primarily from studies of space and airline flight personnel, nuclear plant workers and others exposed occupationally, as well as victims in the vicinity of atomic bomb explosions. The findings remain inconclusive due to population inconsistencies and complex interactions among total dose, dose rate, radiation quality and age at exposure. Thus, safe limits for low dose occupational irradiation are currently based on data obtained with doses far exceeding the levels expected for the general population and health risks have been largely extrapolated using the linear-nonthreshold dose-response model. The overall working hypothesis of the present study is that priming with low dose, low-linear energy transfer (LET) radiation can ameliorate the response to acute high-dose radiation exposure. We also propose that the efficacy of low-dose induced protection will be dependent upon the form and regimen of the high-dose exposure: photons versus protons versus simulated solar particle event protons (sSPE). The emphasis has been on gene expression and function of CD4+ T helper (Th) lymphocytes harvested from spleens of whole-body irradiated C57BL/6 mice, a strain that provides the genetic background for many genetically engineered strains. Evaluations of the responses of other selected cells, tissues such as skin, and organs such as lung, liver and brain were also initiated (partially funded by other sources). The long-term goal is to provide information

  19. The AE9/AP9/SPM Next Generation Radiation Specification Models - Progress Report

    Science.gov (United States)

    O'Brien, Paul; Johnston, William Robert; Huston, Stuart; Guild, Timothy

    2016-07-01

    The AE9/AP9/SPM model has now been released to the global satellite design community, with a recent update to version 1.2. We are working on incorporating new data sources, such as AZUR and NASA's Van Allen Probes, while also addressing critiques raised by the science and engineering communities. In particular, we are investigating discrepancies for protons at low altitude and electrons at geostationary altitudes. Finally, we are scoping out architectural improvements to enable features requested by industry: improved stitching between the plasma and radiation models, local time dependence in the plasma model, longitude dependence in the electron radiation model, and solar cycle variation in the low altitude protons. We provide a brief update on the status of the model, discrepancy investigations, and plans for the future.

  20. Kidney Specific Protein-Positive Cells Derived from Embryonic Stem Cells Reproduce Tubular Structures In Vitro and Differentiate into Renal Tubular Cells

    OpenAIRE

    Ryuji Morizane; Toshiaki Monkawa; Shizuka Fujii; Shintaro Yamaguchi; Koichiro Homma; Yumi Matsuzaki; Hideyuki Okano; Hiroshi Itoh

    2013-01-01

    Embryonic stem cells and induced pluripotent stem cells have the ability to differentiate into various organs and tissues, and are regarded as new tools for the elucidation of disease mechanisms as well as sources for regenerative therapies. However, a method of inducing organ-specific cells from pluripotent stem cells is urgently needed. Although many scientists have been developing methods to induce various organ-specific cells from pluripotent stem cells, renal lineage cells have yet to be...

  1. RB1 status in triple negative breast cancer cells dictates response to radiation treatment and selective therapeutic drugs.

    Directory of Open Access Journals (Sweden)

    Tyler J W Robinson

    Full Text Available Triple negative breast cancer (TNBC includes basal-like and claudin-low subtypes for which only chemotherapy and radiation therapy are currently available. The retinoblastoma (RB1 tumor suppressor is frequently lost in human TNBC. Knockdown of RB1 in luminal BC cells was shown to affect response to endocrine, radiation and several antineoplastic drugs. However, the effect of RB1 status on radiation and chemo-sensitivity in TNBC cells and whether RB1 status affects response to divergent or specific treatment are unknown. Using multiple basal-like and claudin-low cell lines, we hereby demonstrate that RB-negative TNBC cell lines are highly sensitive to gamma-irradiation, and moderately more sensitive to doxorubicin and methotrexate compared to RB-positive TNBC cell lines. In contrast, RB1 status did not affect sensitivity of TNBC cells to multiple other drugs including cisplatin (CDDP, 5-fluorouracil, idarubicin, epirubicin, PRIMA-1(met, fludarabine and PD-0332991, some of which are used to treat TNBC patients. Moreover, a non-biased screen of ∼3400 compounds, including FDA-approved drugs, revealed similar sensitivity of RB-proficient and -deficient TNBC cells. Finally, ESA(+/CD24(-/low/CD44(+ cancer stem cells from RB-negative TNBC lines were consistently more sensitive to gamma-irradiation than RB-positive lines, whereas the effect of chemotherapy on the cancer stem cell fraction varied irrespective of RB1 expression. Our results suggest that patients carrying RB-deficient TNBCs would benefit from gamma-irradiation as well as doxorubicin and methotrexate therapy, but not necessarily from many other anti-neoplastic drugs.

  2. Specific features of radiative recombination spectra of ZnIn2S4 single crystals

    International Nuclear Information System (INIS)

    Radiative recombination spectra of Mn-doped zinc tioindat single crystals have been analyzed in the work. The emission spectra interval close to its maximum (1.91 ± 0.2 eV) contains a number of special features which were identified by us as intra-center transitions. We attribute the special features observed on the complex emission spectra to this type of transition by their decomposition into simple lines using the Alentsev-Foch method. (authors)

  3. Antarctic Specific Features of the Greenhouse Effect : A Radiative Analysis Using Measurements and Models

    OpenAIRE

    Schmithüsen, Holger

    2015-01-01

    CO2 is the strongest anthropogenic forcing agent for climate change since pre-industrial times. Like other greenhouse gases, CO2 absorbs terrestrial surface radiation and causes emission from the atmosphere to space. As the surface is generally warmer than the atmosphere, the total long-wave emission to space is commonly less than the surface emission. However, this does not hold true for the high elevated areas of central Antarctica. For this region, it is shown that the greenhouse effect of...

  4. Non-Destructive Detection and Separation of Radiation Damaged Cells in Miniaturized, Inexpensive Device Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Our objective is to develop and demonstrate a novel microfluidic device for non-destructive identification, sorting and counting of radiation damaged cells. A major...

  5. Non-Destructive Detection and Separation of Radiation Damaged Cells in Miniaturized, Inexpensive Device Project

    Data.gov (United States)

    National Aeronautics and Space Administration — There is a clear and well-identified need for rapid, efficient, non-destructive detection and isolation of radiation damaged cells. Available commercial...

  6. Gender Specific Mutation Incidence and Survival Associations in Clear Cell Renal Cell Carcinoma (CCRCC.

    Directory of Open Access Journals (Sweden)

    Christopher J Ricketts

    Full Text Available Renal cell carcinoma (RCC is diagnosed in >200,000 individuals worldwide each year, accounting for ~2% of all cancers, but the spread of this disease amongst genders is distinctly uneven. In the U.S. the male:female incidence ratio is approximately 2:1. A potential hypothesis is mutation spectra may differ between tumors dependent upon the gender of the patient, such as mutations of X chromosome encoded genes being more prevalent in male-derived tumors. Combined analysis of three recent large-scale clear cell renal cell carcinoma (CCRCC mutation sequencing projects identified a significantly increased mutation frequency of PBRM1 and the X chromosome encoded KDM5C in tumors from male patients and BAP1 in tumors from female patients. Mutation of BAP1 had previously been significantly associated with poorer overall survival; however, when stratified by gender, mutation of BAP1 only significantly affected overall survival in female patients. Mutation of chromatin remodeling genes alters gene regulation, but the overall effect of these alterations may also be modified by the presence of other gender specific factors. Thus, the combination of gender and mutation of a specific gene, such as BAP1, may have implications not only for prognosis but also for understanding the role of chromatin remodeling gene mutations in kidney cancer progression.

  7. Multiple Effector Functions Mediated by Human Immunodeficiency Virus-Specific CD4+ T-Cell Clones

    OpenAIRE

    Norris, Philip J.; Sumaroka, Marina; Brander, Christian; Moffett, Howell F.; Boswell, Steven L.; Nguyen, Tam; Sykulev, Yuri; Walker, Bruce D; Rosenberg, Eric S.

    2001-01-01

    Mounting evidence suggests that human immunodeficiency virus type 1 (HIV-1) Gag-specific T helper cells contribute to effective antiviral control, but their functional characteristics and the precise epitopes targeted by this response remain to be defined. In this study, we generated CD4+ T-cell clones specific for Gag from HIV-1-infected persons with vigorous Gag-specific responses detectable in peripheral blood mononuclear cells. Multiple peptides containing T helper epitopes were identifie...

  8. Defining cell-type specificity at the transcriptional level in human disease

    OpenAIRE

    Ju, Wenjun; Greene, Casey S; Eichinger, Felix; Nair, Viji; Hodgin, Jeffrey B.; Bitzer, Markus; Lee, Young-Suk; Zhu, Qian; Kehata, Masami; Li, Min; Jiang, Song; Rastaldi, Maria Pia; Cohen, Clemens D; Troyanskaya, Olga G.; Kretzler, Matthias

    2013-01-01

    Cell-lineage–specific transcripts are essential for differentiated tissue function, implicated in hereditary organ failure, and mediate acquired chronic diseases. However, experimental identification of cell-lineage–specific genes in a genome-scale manner is infeasible for most solid human tissues. We developed the first genome-scale method to identify genes with cell-lineage–specific expression, even in lineages not separable by experimental microdissection. Our machine-learning–based approa...

  9. Radiation signature on exposed cells: Relevance in dose estimation

    OpenAIRE

    Perumal, Venkatachalam; Gnana Sekaran, Tamizh Selvan; Raavi, Venkateswarlu; Basheerudeen, Safa Abdul Syed; Kanagaraj, Karthik; Chowdhury, Amith Roy; Paul, Solomon FD

    2015-01-01

    The radiation is considered as a double edged sword, as its beneficial and detrimental effects have been demonstrated. The potential benefits are being exploited to its maximum by adopting safe handling of radionuclide stipulated by the regulatory agencies. While the occupational workers are monitored by personnel monitoring devices, for general publics, it is not a regular practice. However, it can be achieved by using biomarkers with a potential for the radiation triage and medical manageme...

  10. The role of autophagy in sensitizing malignant glioma cells to radiation therapy

    Institute of Scientific and Technical Information of China (English)

    Wenzhuo Zhuang; Zhenghong Qin; Zhongqin Liang

    2009-01-01

    Malignant gliomas representthe majority of primary brain tumors.The current standard treatments for malignant gliomas include surgical resection,radiation therapy,and chemotherapy.Radiotherapy,a standard adjuvant therapy,confers some survival advantages,but resistance of the glioma cells to the efficacy of radiation limits the success of the treatment.The mechanisms underlying glioma cell radioresistance have remained elusive.Autophagy is a protein degradation system characterized by a prominent formation of double-membrane vesicles in the cytoplasm.Recent studies suggest that autophagy may be important in the regulation of cancer development and progression and in determining the response of tumor cells to anticancer therapy.Also,autophagy is a novel response of glioma cells to ionizing radiation.Autophagic cell death is considered programmed cell death type Ⅱ,whereas apoptosis is programmed cell death type Ⅰ.These two types of cell death are predominantly distinctive,but many studies demonstrate a cross-talk between them.Whether autophagy in cancer cells causes death or protects cells is controversial.The regulatory pathways of autophagy share several molecules.P13K/Akt/Mtor,DNA-PK,tumor suppressor genes, mitochondrial damage,and lysosome may play important roles in radiation-induced autophagy in glioma cells.Recently,a highly tumorigenic glioma tumor subpopulation,termed cancer stem cell or tumor-initiating cell,has been shown to promote therapeutic resistance.This review summarizes the main mediators associated with radiation-induced autophagy in malignant glioma cells and discusses the implications of the cancer stem cell hypothesis for the development of future therapies for brain tumors.

  11. M-BAND Study of Radiation-Induced Chromosome Aberrations in Human Epithelial Cells: Radiation Quality and Dose Rate Effects

    Science.gov (United States)

    Hada, Megumi; Cucinotta, Francis; Wu, Honglu

    2009-01-01

    The advantage of the multicolor banding in situ hybridization (mBAND) technique is its ability to identify both inter- (translocation to unpainted chromosomes) and intra- (inversions and deletions within a single painted chromosome) chromosome aberrations simultaneously. To study the detailed rearrangement of low- and high-LET radiation induced chromosome aberrations in human epithelial cells (CH184B5F5/M10) in vitro, we performed a series of experiments with Cs-137 gamma rays of both low and high dose rates, neutrons of low dose rate and 600 MeV/u Fe ions of high dose rate, with chromosome 3 painted with multi-binding colors. We also compared the chromosome aberrations in both 2- and 3-dimensional cell cultures. Results of these experiments revealed the highest chromosome aberration frequencies after low dose rate neutron exposures. However, detailed analysis of the radiation induced inversions revealed that all three radiation types induced a low incidence of simple inversions. Most of the inversions in gamma-ray irradiated samples were accompanied by other types of intra-chromosomal aberrations but few inversions were accompanied by inter-chromosomal aberrations. In contrast, neutrons and Fe ions induced a significant fraction of inversions that involved complex rearrangements of both inter- and intrachromosomal exchanges. The location of the breaks involved in chromosome exchanges was analyzed along the painted chromosome. The breakpoint distribution was found to be randomly localized on chromosome 3 after neutron or Fe ion exposure, whereas non-random distribution with clustering breakpoints was observed after -ray exposure. Our comparison of chromosome aberration yields between 2- and 3-dimensional cell cultures indicated a significant difference for gamma exposures, but not for Fe ion exposures. These experimental results indicated that the track structure of the radiation and the cellular/chromosome structure can both affect radiation-induced chromosome

  12. ANALYSES OF CHROMOSOME ABERRATIONS IN LYMPHOCYTES AND BONE MARROW CELLS INDUCED BY RADIATION OR BENZENE

    Institute of Scientific and Technical Information of China (English)

    张鸿源; 王兰金; 等

    1995-01-01

    The chromosomoe and chromatid type aberration can be induced by benzene and the dicentric and ring ones were not observed in vitro experiment but observed in vivo one.In vitro experiment a good linear reression can be given between benzene concentrations and total aberration cells while power regression for radiation dose.The chromosome aberrations induced by benzene combined with radiation in rabbit blood lymphocytes are higher than in bone marryow cells.

  13. Low- and high-LET radiation drives clonal expansion of lung progenitor cells in vivo.

    Science.gov (United States)

    Farin, Alicia M; Manzo, Nicholas D; Kirsch, David G; Stripp, Barry R

    2015-01-01

    Abundant populations of epithelial progenitor cells maintain the epithelium along the proximal-to-distal axis of the airway. Exposure of lung tissue to ionizing radiation leads to tissue remodeling and potential cancer initiation or progression. However, little is known about the effects of ionizing radiation on airway epithelial progenitor cells. We hypothesized that ionizing radiation exposure will alter the behavior of airway epithelial progenitor cells in a radiation dose- and quality-dependent manner. To address this hypothesis, we cultured primary airway epithelial cells isolated from mice exposed to various doses of 320 kVp X ray or 600 MeV/nucleon (56)Fe ions in a 3D epithelial-fibroblast co-culture system. Colony-forming efficiency of the airway epithelial progenitor cells was assessed at culture day 14. In vivo clonogenic and proliferative potentials of airway epithelial progenitor cells were measured after exposure to ionizing radiation by lineage tracing and IdU incorporation. Exposure to both X rays and (56)Fe resulted in a dose-dependent decrease in the ability of epithelial progenitors to form colonies in vitro. In vivo evidence for increased clonogenic expansion of epithelial progenitors was observed after exposure to both X rays and (56)Fe. Interestingly, we found no significant increase in the epithelial proliferative index, indicating that ionizing radiation does not promote increased turnover of the airway epithelium. Therefore, we propose a model in which radiation induces a dose-dependent decrease in the pool of available progenitor cells, leaving fewer progenitors able to maintain the airway long-term. This work provides novel insights into the effects of ionizing radiation exposure on airway epithelial progenitor cell behavior. PMID:25564721

  14. Two cases of basal cell carcinoma arising from chronic radiation dermatitis

    Energy Technology Data Exchange (ETDEWEB)

    Wakamori, Takeshi; Takenaka, Hideya; Ueda, Eiichiro; Katoh, Norito; Kishimoto, Saburo [Kyoto Prefectural Univ. of Medicine (Japan)

    2003-04-01

    A 48-year-old female and a 51-year-old male with basal cell carcinoma (BCC) arising from chronic radiation dermatitis are reviewed. They are treated with radiotherapy for hemangioma on their right cheek in their childhood. Review in the literature showed high incidence of the histological diagnosis of malignant skin tumors arising from chronic radiation dermatitis are follows: squamous cell carcinoma (SCC), BCC, sarcoma, and Bowen's disease. (author)

  15. Germ cell toxicity: significance in genetic and fertility effects of radiation and chemicals

    International Nuclear Information System (INIS)

    The primordial germ cells originate in the region of the caudal end of the primitive streak, root of the allantois, and yolk sac splanchnopleure, and migrate to the gonadal ridges where they divide to form the oogonia of the female and gonocytes of the male. In the female, the transition to oocytes occurs in utero, and the female mammal is born with a finite number of oocytes that cannot be replaced. By contrast, the gonocytes of the male initiate divisions soon after birth to form the spermatogonial stem cells, which persist throughout reproductive life of the male and are capable of regenerating the seminiferous epithelium after injury. As a result of these basic differences in gametogenesis, the response of the male and female to radiation and chemicals is different. The response of both the male and female changes with development of the embryonic to the adult gonad, and with differentiation and maturation in the adult. The primordial germ cells, early oocytes, and differentiating spermatogonia of the adult male are unusually sensitive to the cytotoxic action of noxious agents, but each agent elicits a specific response owing to the intricate biochemical and physiological changes associated with development and maturation of the gametes. The relationship of germ cell killing to fertility is direct, and long-term fertility effects can be predicted from histological analysis of the gonads. The relationship to genetic effects, on the other hand, is indirect, and acts primarily by limiting the cell stages available for testing, by affecting the distribution of mitotically active stem cells among the different stages of the mitotic cycle, and thereby changing both the type and frequency of genetic effects observed

  16. Cell-specific Regulation of APOBEC3F by Interferons

    Institute of Scientific and Technical Information of China (English)

    Songcheng YING; Xuzhao ZHANG; Phuong Thi Nguyen SARKIS; Rongzhen XU; Xiaofang YU

    2007-01-01

    Human cytidine deaminase APOBEC3F (A3F) has broad anti-viral activity against hepatitis B virus and retroviruses including human immunodeficiency virus type 1. However, its regulation in viral natural target cells such CD4+ T lymphocytes, macrophages, and primary liver cells has not been well studied. Here we showed that A3F was up-regulated by interferon (IFN)-α in primary hepatocytes and multiple liver cell lines as well as macrophages. Although the IFN-α signaling pathway was active in T lymphoid cells and induction of other IFN stimulated genes such as PKR was detected, A3F and APOBEC3G (A3G) were not induced by IFN-o in these cells. Thus, additional factors other than known IFN-stimulated genes also regulated IFN-α-induced A3F expression distinctly. A3F and A3G expression levels in primary hepatocytes, especially after IFN-α stimulation, were comparable to those in CD4+ T lymphocytes in some individuals. Significant variations of A3F and A3G expression in primary hepatocytes from various subjects were observed. Individual variations in A3F and/or A3G regulation and expression might influence the clinical outcomes of hepatitis B infection.

  17. Cell type-specific neuroprotective activity of untranslocated prion protein.

    Directory of Open Access Journals (Sweden)

    Elena Restelli

    Full Text Available BACKGROUND: A key pathogenic role in prion diseases was proposed for a cytosolic form of the prion protein (PrP. However, it is not clear how cytosolic PrP localization influences neuronal viability, with either cytotoxic or anti-apoptotic effects reported in different studies. The cellular mechanism by which PrP is delivered to the cytosol of neurons is also debated, and either retrograde transport from the endoplasmic reticulum or inefficient translocation during biosynthesis has been proposed. We investigated cytosolic PrP biogenesis and effect on cell viability in primary neuronal cultures from different mouse brain regions. PRINCIPAL FINDINGS: Mild proteasome inhibition induced accumulation of an untranslocated form of cytosolic PrP in cortical and hippocampal cells, but not in cerebellar granules. A cyclopeptolide that interferes with the correct insertion of the PrP signal sequence into the translocon increased the amount of untranslocated PrP in cortical and hippocampal cells, and induced its synthesis in cerebellar neurons. Untranslocated PrP boosted the resistance of cortical and hippocampal neurons to apoptotic insults but had no effect on cerebellar cells. SIGNIFICANCE: These results indicate cell type-dependent differences in the efficiency of PrP translocation, and argue that cytosolic PrP targeting might serve a physiological neuroprotective function.

  18. Perforin and Fas in murine gammaherpesvirus-specific CD8(+) T cell control and morbidity

    DEFF Research Database (Denmark)

    Topham, D J; Cardin, R C; Christensen, Jan Pravsgaard;

    2001-01-01

    The immune system uses both virus-specific T cells and B cells to control the acute and latent phases of respiratory infection with the murine gammaherpesvirus 68 (gammaHV-68). We sought to further define the important effector mechanisms for CD8(+) T cells. First, depletion of the CD4(+) T cells...

  19. Estimation of a "radiatively correct" black carbon specific absorption during the Mexico City Metropolitan Area (MCMA 2003 field campaign

    Directory of Open Access Journals (Sweden)

    J. C. Barnard

    2007-01-01

    Full Text Available During the Mexico City Metropolitan Area (MCMA field campaign of 2003, measurements of the shortwave radiation field allowed the inference of the black carbon (BC specific absorption, αλ, defined as the monochromatic absorption cross section per unit mass (with units of m2/g. The averaged values of αλ derived from the method here are either 8.9 m2/g or 8.2 m2/g at 500 nm, depending upon the physical and optical parameters assumed for BC. These results are reasonably consistent with those of Schuster et al. (2005, 9.5 m2/g, and Baumgartner et al. (2002, 7.0 m2/g, both measured at 550 nm. The αλ values reported in this paper should only be considered effective, "radiatively correct" values because when used in radiative transfer calculations the calculated irradiances match the measured irradiances at 500 nm. The specific absorption so defined can assume a wide range of values, depending upon: (1 the assumptions made prior to the retrieval (e.g., shell/core aerosol configuration, and (2 values chosen for BC density and refractive index. The range of possible values is large, corresponding to a "worst case" uncertainty of about ±70%, assuming that all errors are additive and of the same sign so that no error cancellation occurs.

  20. Hypofractionated radiation therapy for the treatment of feline facial squamous cell carcinoma; Hypofractionated radiation therapy for the treatment of feline facial squamous cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, S.C.S.; Corgozinho, K.B.; Holguin, P.G.; Ferreira, A.M.R., E-mail: simonecsc@gmail.co [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Carvalho, L.A.V. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil); Canary, P.C.; Reisner, M. [Hospital Universitario Clementino Fraga Filho (HUCFF/UFRJ), Rio de Janeiro, RJ (Brazil); Pereira, A.N.; Souza, H.J.M. [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropedica, RJ (Brazil)

    2010-07-01

    The efficacy of hypofractionated radiation protocol for feline facial squamous cell carcinoma was evaluated. Hypofractionated radiation therapy was applied to five cats showing single or multiple facial squamous cell carcinomas, in a total of ten histologically confirmed neoplastic lesions. Of the lesions, two were staged as T{sub 1}, four as T{sub 2}, two as T{sub 3}, and two as T{sub 4}. The animals were submitted to four radiation fractions from 7.6 to 10 grays each, with one week intervals. The equipment was a linear accelerator with electrons beam. The cats were evaluated weekly during the treatment and 30 and 60 days after the end of the radiation therapy. In this study, 40% of the lesions had complete remission, 40% partial remission, and 20% did not respond to the treatment. Response rates were lower as compared to other protocols previously used. However, hypofractionated radiation protocol was considered safe for feline facial squamous cell carcinoma. (author)

  1. Radiation Dose-effects on Cell Cycle, Apoptosis, and Marker Expression of Ataxia Telangiectasia-Heterozygous Human Breast Epithelial Cells

    Science.gov (United States)

    Cruz, A.; Bors, K.; Jansen, H.; Richmond, R.

    2003-01-01

    Ataxia-telangiectasia (A-T) is a radiation-sensitive genetic condition. AT-heterozygous human mammary epithelial cells (HMEC) were irradiated using a Cs137 source in order to compare cell cycle, apoptosis, and marker expression responses across 3 radiation doses. No differences in cell cycle and apoptosis were found with any of the radiation doses used (30, 60, and 90 rads) compared with the unirradiated control (0 rad). At the same doses, however, differences were found in marker expression, such as keratin 18 (kl8), keratin 14 (k14), insulin-like growth factor I receptor (IGF-IR), and connexin 43 (cx43). This may indicate that radiation sensitivity in the heterozygous state may be initiated through signal transduction responses.

  2. Andrographolide Sensitizes Ras-Transformed Cells to Radiation in vitro and in vivo

    International Nuclear Information System (INIS)

    Purpose: Increasing the sensitivity of tumor cells to radiation is a major goal of radiotherapy. The present study investigated the radiosensitizing effects of andrographolide and examined the molecular mechanisms of andrographolide-mediated radiosensitization. Methods and Materials: An H-ras-transformed rat kidney epithelial (RK3E) cell line was used to measure the radiosensitizing effects of andrographolide in clonogenic assays, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide assays, and a xenograft tumor growth model. The mechanism of andrographolide-sensitized cell death was analyzed using annexin V staining, caspase 3 activity assays, and terminal transferase uridyl nick end labeling assays. The roles of nuclear factor kappa B (NF-κB) and Akt in andrographolide-mediated sensitization were examined using reporter assays, electrophoretic mobility shift assays, and Western blotting. Results: Concurrent andrographolide treatment (10 μM, 3 h) sensitized Ras-transformed cells to radiation in vitro (sensitizer enhancement ratio, 1.73). Andrographolide plus radiation (one dose of 300 mg/kg peritumor andrographolide and one dose of 6 Gy radiation) resulted in significant tumor growth delay (27 ± 2.5 days) compared with radiation alone (22 ± 1.5 days; p <.05). Radiation induced apoptotic markers (e.g., caspase-3, membrane reversion, DNA fragmentation), and andrographolide treatment did not promote radiation-induced apoptosis. However, the protein level of activated Akt was significantly reduced by andrographolide. NF-κB activity was elevated in irradiated Ras-transformed cells, and andrographolide treatment significantly reduced radiation-induced NF-κB activity. Conclusion: Andrographolide sensitized Ras-transformed cells to radiation both in vitro and in vivo. Andrographolide-mediated radiosensitization was associated with downregulation of Akt and NF-κB activity. These observations indicate that andrographolide is a novel radiosensitizing agent

  3. Breast cancers radiation-resistance: key role of the cancer stem cells marker CD24

    International Nuclear Information System (INIS)

    This work focuses on the characterization of radiation-resistant breast cancer cells, responsible for relapse after radiotherapy. The 'Cancer Stem Cells' (CSC) theory describes a radiation-resistant cellular sub-population, with enhanced capacity to induce tumors and proliferate. In this work, we show that only the CSC marker CD24-/low defines a radiation resistant cell population, able to transmit the 'memory' of irradiation, expressed as long term genomic instability in the progeny of irradiated cells. We show that CD24 is not only a marker, but is an actor of radiation-response. So, CD24 expression controls cell proliferation in vitro and in vivo, and ROS level before and after irradiation. As a result, CD24-/low cells display enhanced radiation-resistance and genomic stability. For the first time, our results attribute a role to CD24-/low CSCs in the transmission of genomic instability. Moreover, by providing informations on tumor intrinsic radiation-sensitivity, CD24- marker could help to design new radiotherapy protocols. (author)

  4. Role of T cell receptor affinity in the efficacy and specificity of adoptive T cell therapies

    Directory of Open Access Journals (Sweden)

    Jennifer D. Stone

    2013-08-01

    Full Text Available Over the last several years, there has been considerable progress in the treatment of cancer using gene modified adoptive T cell therapies. Two approaches have been used, one involving the introduction of a conventional alpha-beta T cell receptor (TCR against a pepMHC cancer antigen, and the second involving introduction of a chimeric antigen receptor (CAR consisting of a single-chain antibody as an Fv fragment (scFv linked to transmembrane and signaling domains. In this review, we focus on one aspect of TCR-mediated adoptive T cell therapies, the impact of the affinity of the alpha-beta TCR for the pepMHC cancer antigen on both efficacy and specificity. We discuss the advantages of higher affinity TCRs in mediating potent activity of CD4 T cells. This is balanced with the potential disadvantage of higher affinity TCRs in mediating greater self-reactivity against a wider range of structurally similar antigenic peptides, especially in synergy with the CD8 co-receptor. Both TCR affinity and target selection will influence potential safety issues. We suggest pre-clinical strategies that might be used to examine each TCR for possible on-target and off-target side effects due to self-reactivities, and to adjust TCR affinities accordingly.

  5. Quantifying immediate radiative forcing by black carbon and organic matter with the Specific Forcing Pulse

    Directory of Open Access Journals (Sweden)

    T. C. Bond

    2011-02-01

    Full Text Available Climatic effects of short-lived climate forcers (SLCFs differ from those of long-lived greenhouse gases, because they occur rapidly after emission and because they depend upon the region of emission. The distinctive temporal and spatial nature of these impacts is not captured by measures that rely on global averages or long time integrations. Here, we propose a simple measure, the Specific Forcing Pulse (SFP, to quantify climate warming or cooling by these pollutants, where we define "immediate" as occurring primarily within the first year after emission. SFP is the amount of energy added to or removed from a receptor region in the Earth-atmosphere system by a chemical species, per mass of emission in a source region. We limit the application of SFP to species that remain in the atmosphere for less than one year. Metrics used in policy discussions, such as total forcing or global warming potential, are easily derived from SFP. However, SFP conveys purely physical information without incurring the policy implications of choosing a time horizon for the global warming potential.

    Using one model (Community Atmosphere Model, or CAM, we calculate values of SFP for black carbon (BC and organic matter (OM emitted from 23 source-region combinations. Global SFP for both atmosphere and cryosphere impacts is divided among receptor latitudes. SFP is usually greater for open-burning emissions than for energy-related (fossil-fuel and biofuel emissions because of the timing of emission. Global SFP for BC varies by about 45% for energy-related emissions from different regions. This variation would be larger except for compensating effects. When emitted aerosol has larger cryosphere forcing, it often has lower atmosphere forcing because of less deep convection and a shorter atmospheric lifetime.

    A single model result is insufficient to capture uncertainty. We develop a best estimate and uncertainties for SFP by combining forcing results from