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Dubach RA, Dubach JM. Autocorrelation analysis of a phenotypic screen reveals hidden drug activity. Sci Rep 2024; 14:10046. [PMID: 38698021 PMCID: PMC11066105 DOI: 10.1038/s41598-024-60654-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 04/25/2024] [Indexed: 05/05/2024] Open
Abstract
Phenotype based screening is a powerful tool to evaluate cellular drug response. Through high content fluorescence imaging of simple fluorescent labels and complex image analysis phenotypic measurements can identify subtle compound-induced cellular changes unique to compound mechanisms of action (MoA). Recently, a screen of 1008 compounds in three cell lines was reported where analysis detected changes in cellular phenotypes and accurately identified compound MoA for roughly half the compounds. However, we were surprised that DNA alkylating agents and other compounds known to induce or impact the DNA damage response produced no measured activity in cells with fluorescently labeled 53BP1-a canonical DNA damage marker. We hypothesized that phenotype analysis is not sensitive enough to detect small changes in 53BP1 distribution and analyzed the screen images with autocorrelation image analysis. We found that autocorrelation analysis, which quantifies fluorescently-labeled protein clustering, identified higher compound activity for compounds and MoAs known to impact the DNA damage response, suggesting altered 53BP1 recruitment to damaged DNA sites. We then performed experiments under more ideal imaging settings and found autocorrelation analysis to be a robust measure of changes to 53BP1 clustering in the DNA damage response. These results demonstrate the capacity of autocorrelation to detect otherwise undetectable compound activity and suggest that autocorrelation analysis of specific proteins could serve as a powerful screening tool.
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Affiliation(s)
| | - J Matthew Dubach
- Institute for Innovation in Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, USA.
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2
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Giatromanolaki A, Kavazis C, Gkegka AG, Kouroupi M, Tsaroucha A, Pitiakoudis M, Koukourakis MI. Tumor-infiltrating lymphocytes, PD-L1, and MMR-deficiency combined characterization may identify subgroups of rectal cancer patients who would benefit from immunotherapy. Immunobiology 2023; 228:152756. [PMID: 38860277 DOI: 10.1016/j.imbio.2023.152756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Revised: 10/03/2023] [Accepted: 10/17/2023] [Indexed: 06/12/2024]
Abstract
INTRODUCTION Mismatch repair deficiency, immunological fertility, and PD-L1 expression status are key histopathological and molecular features defining tumor responsiveness to immunotherapy and, eventually, prognosis. These were investigated in a series of locally advanced rectal cancer patients treated with postoperative chemotherapy and radiotherapy. MATERIALS AND METHODS Tumor-infiltrating lymphocyte (TIL) density was assessed in hematoxylin-eosin tissue sections. PD-L1 expression and the expression of MMR proteins (MLH1, PSM2, MSH2, and MSH6) were assessed with immunohistochemistry. Their association with histopathological variables (node involvement and tumor budding) and prognosis was assessed. RESULTS The TIL-density was significantly higher in the invading tumor front and was inversely related to tumor budding and directly with better overall survival (OS) and distant metastasis-free survival (DMFS) (p = 0.02 and 0.02, respectively). Cancer cell PD-L1 expression was related to high TIL-density (p < 0.01) but not to prognosis, although its overexpression defined a trend for poorer OS in patients with high TIL-density. High PD-L1 expression by stroma infiltrating immune cells was linked with better OS and DMFS (p = 0.007 and 0.001, respectively. MMR deficiency was recorded in 26.2 % of cases, and this was linked with higher TIL-density, but not with prognosis. CONCLUSIONS Dense intratumoral lymphocytic infiltration relates to a better prognosis in rectal cancer, although it is also linked with PD-L1 expression that may adversely modulate the anti-tumor effects of TILs. This latter subgroup of patients (high TIL-density/high cancer cell PD-L1 expression) could be an additional target for anti-PD-1/PD-L1 immunotherapy, along with the established subgroup of MMR deficient patients.
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Affiliation(s)
- Alexandra Giatromanolaki
- Department of Pathology, University Hospital of Alexandroupolis, Alexandroupolis, Greece; Department of Radiotherapy/Oncology, Democritus University of Thrace, University Hospital of Alexandroupolis, Alexandroupolis, Greece
| | - Christos Kavazis
- Departments of Surgery, University Hospital of Alexandroupolis, Alexandroupolis, Greece; Department of Radiotherapy/Oncology, Democritus University of Thrace, University Hospital of Alexandroupolis, Alexandroupolis, Greece
| | - Anastasia G Gkegka
- Department of Pathology, University Hospital of Alexandroupolis, Alexandroupolis, Greece; Department of Radiotherapy/Oncology, Democritus University of Thrace, University Hospital of Alexandroupolis, Alexandroupolis, Greece
| | - Maria Kouroupi
- Department of Pathology, University Hospital of Alexandroupolis, Alexandroupolis, Greece; Department of Radiotherapy/Oncology, Democritus University of Thrace, University Hospital of Alexandroupolis, Alexandroupolis, Greece
| | - Alexandra Tsaroucha
- Laboratory of Experimental Surgery and Surgical Research, University Hospital of Alexandroupolis, Alexandroupolis, Greece; Department of Radiotherapy/Oncology, Democritus University of Thrace, University Hospital of Alexandroupolis, Alexandroupolis, Greece
| | - Michael Pitiakoudis
- Departments of Surgery, University Hospital of Alexandroupolis, Alexandroupolis, Greece; Department of Radiotherapy/Oncology, Democritus University of Thrace, University Hospital of Alexandroupolis, Alexandroupolis, Greece
| | - Michael I Koukourakis
- Laboratory of Experimental Surgery and Surgical Research, University Hospital of Alexandroupolis, Alexandroupolis, Greece; Department of Radiotherapy/Oncology, Democritus University of Thrace, University Hospital of Alexandroupolis, Alexandroupolis, Greece.
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3
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Polgár S, Schofield PN, Madas BG. Datasets of in vitro clonogenic assays showing low dose hyper-radiosensitivity and induced radioresistance. Sci Data 2022; 9:555. [PMID: 36075916 PMCID: PMC9458642 DOI: 10.1038/s41597-022-01653-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 08/19/2022] [Indexed: 11/19/2022] Open
Abstract
Low dose hyper-radiosensitivity and induced radioresistance are primarily observed in surviving fractions of cell populations exposed to ionizing radiation, plotted as the function of absorbed dose. Several biophysical models have been developed to quantitatively describe these phenomena. However, there is a lack of raw, openly available experimental data to support the development and validation of quantitative models. The aim of this study was to set up a database of experimental data from the public literature. Using Google Scholar search, 46 publications with 101 datasets on the dose-dependence of surviving fractions, with clear evidence of low dose hyper-radiosensitivity, were identified. Surviving fractions, their uncertainties, and the corresponding absorbed doses were digitized from graphs of the publications. The characteristics of the cell line and the irradiation were also recorded, along with the parameters of the linear-quadratic model and/or the induced repair model if they were provided. The database is available in STOREDB, and can be used for meta-analysis, for comparison with new experiments, and for development and validation of biophysical models. Measurement(s) | surviving fraction of cells | Technology Type(s) | optical microscopy | Factor Type(s) | absorbed dose | Sample Characteristic - Organism | Homo sapiens • Chinese hamster • Rattus sp. | Sample Characteristic - Environment | cell culture |
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Affiliation(s)
- Szabolcs Polgár
- Doctoral School of Physics, ELTE Eötvös Loránd University, Budapest, Hungary.,Environmental Physics Department, Centre for Energy Research, Budapest, Hungary
| | - Paul N Schofield
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Balázs G Madas
- Environmental Physics Department, Centre for Energy Research, Budapest, Hungary. .,Department of Physical Chemistry and Materials Science, Budapest University of Technology and Economics, Budapest, Hungary.
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4
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Sheehan B, Neeb A, Buroni L, Paschalis A, Riisnaes R, Gurel B, Gil V, Miranda S, Crespo M, Guo C, Jiménez Vacas J, Figueiredo I, Ferreira A, Welti J, Yuan W, Carreira S, Sharp A, de Bono J. Prostate-Specific Membrane Antigen Expression and Response to DNA Damaging Agents in Prostate Cancer. Clin Cancer Res 2022; 28:3104-3115. [PMID: 35552383 PMCID: PMC9365343 DOI: 10.1158/1078-0432.ccr-21-4531] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 03/15/2022] [Accepted: 05/09/2022] [Indexed: 01/07/2023]
Abstract
PURPOSE Prostate-specific membrane antigen (PSMA) targeting therapies such as Lutetium-177 (177Lu)-PSMA-617 are affecting outcomes from metastatic castration-resistant prostate cancer (mCRPC). However, a significant subset of patients have prostate cancer cells lacking PSMA expression, raising concerns about treatment resistance attributable at least in part to heterogeneous PSMA expression. We have previously demonstrated an association between high PSMA expression and DNA damage repair defects in mCRPC biopsies and therefore hypothesized that DNA damage upregulates PSMA expression. EXPERIMENTAL DESIGN To test this relationship between PSMA and DNA damage we conducted a screen of 147 anticancer agents (NCI/NIH FDA-approved anticancer "Oncology Set") and treated tumor cells with repeated ionizing irradiation. RESULTS The topoisomerase-2 inhibitors, daunorubicin and mitoxantrone, were identified from the screen to upregulate PSMA protein expression in castration-resistant LNCaP95 cells; this result was validated in vitro in LNCaP, LNCaP95, and 22Rv1 cell lines and in vivo using an mCRPC patient-derived xenograft model CP286 identified to have heterogeneous PSMA expression. As double-strand DNA break induction by topoisomerase-2 inhibitors upregulated PSMA, we next studied the impact of ionizing radiation on PSMA expression; this also upregulated PSMA protein expression in a dose-dependent fashion. CONCLUSIONS The results presented herein are the first, to our knowledge, to demonstrate that PSMA is upregulated in response to double-strand DNA damage by anticancer treatment. These data support the study of rational combinations that maximize the antitumor activity of PSMA-targeted therapeutic strategies by upregulating PSMA.
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Affiliation(s)
| | - Antje Neeb
- The Institute of Cancer Research, London, UK
| | | | - Alec Paschalis
- The Institute of Cancer Research, London, UK
- The Royal Marsden NHS Foundation Trust, Sutton, UK
| | | | - Bora Gurel
- The Institute of Cancer Research, London, UK
| | | | | | | | - Christina Guo
- The Institute of Cancer Research, London, UK
- The Royal Marsden NHS Foundation Trust, Sutton, UK
| | | | | | | | - Jon Welti
- The Institute of Cancer Research, London, UK
| | - Wei Yuan
- The Institute of Cancer Research, London, UK
| | | | - Adam Sharp
- The Institute of Cancer Research, London, UK
- The Royal Marsden NHS Foundation Trust, Sutton, UK
| | - Johann de Bono
- The Institute of Cancer Research, London, UK
- The Royal Marsden NHS Foundation Trust, Sutton, UK
- Corresponding Author: Johann de Bono, Clinical Studies, Institute of Cancer Research, 15 Cotswold Road, Sutton SM2 5NG, UK. Phone: 44-208-722-4029 (Skype); Fax: 44-208-642-7979; E-mail:
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5
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Puukila S, Tharmalingam S, Al-Khayyat W, Peterson J, Hooker AM, Muise S, Boreham DR, Dixon DL. Transcriptomic Response in the Spleen after Whole-Body Low-Dose X-Ray Irradiation. Radiat Res 2021; 196:66-73. [PMID: 33956160 DOI: 10.1667/rade-20-00267.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 04/02/2021] [Indexed: 11/03/2022]
Abstract
As the use of medical radiation procedures continues to rise, it is imperative to further our understanding of the effects of this exposure. The spleen is not known as a particularly radiosensitive organ, although its tolerance to radiation is not well understood. Low-dose radiation exposure has been implicated in beneficial responses, particularly in cell death and DNA damage repair. In this study, adult male rats received 2, 20, 200 mGy or 4 Gy whole-body X-ray irradiation and the transcriptional response in the spleen was analyzed at 0.5, 4 and 24 h postirradiation. We analyzed expression of genes involved in apoptosis, cell cycle progression and DNA damage repair. As expected, 4 Gy irradiated animals demonstrated elevated expression of genes related to apoptosis at 0.5, 4 and 24 h postirradiation in the spleen. These animals also showed upregulation of DNA damage repair genes at 24 h postirradiation. Interestingly, the spleens of 20 mGy irradiated animals showed reduced apoptosis and cell cycle arrest compared to the spleens of sham-irradiated animals. These results further reveal that the cellular response in the spleen to whole-body irradiation differs between low- and high-dose irradiation.
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Affiliation(s)
- S Puukila
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia.,Laurentian University, Sudbury, Canada
| | - S Tharmalingam
- Laurentian University, Sudbury, Canada.,Northern Ontario School of Medicine, Sudbury/Thunder Bay, Canada.,Health Sciences North Research Institute, Sudbury, Canada
| | | | | | - A M Hooker
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia.,Centre for Radiation Research Education and Innovation, University of Adelaide, Adelaide, Australia
| | - S Muise
- McMaster University, Hamilton, Canada
| | - D R Boreham
- Northern Ontario School of Medicine, Sudbury/Thunder Bay, Canada
| | - D-L Dixon
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia.,Northern Ontario School of Medicine, Sudbury/Thunder Bay, Canada
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Bakhtiari E, Monfared AS, Niaki HA, Borzoueisileh S, Niksirat F, Fattahi S, Monfared MK, Gorji KE. The expression of MLH1 and MSH2 genes among inhabitants of high background radiation area of Ramsar, Iran. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2019; 208-209:106012. [PMID: 31323602 DOI: 10.1016/j.jenvrad.2019.106012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Revised: 06/16/2019] [Accepted: 07/03/2019] [Indexed: 06/10/2023]
Abstract
Previous studies evidenced the critical role of the mismatch repair system in DNA damage recognition, cell cycle arrest, apoptosis and DNA repair. MLH1 and MSH2 genes belong to repairing complexes of mismatch repair system. The side effects of ionizing radiation on the human health were proved, but researches on the inhabitants of high background radiation areas, with extra-ordinary radiation exposure, showed that the prevalence of cancer or radiation-related diseases is not significantly higher than normal background areas. The city of Ramsar, in northern Iran, has the highest level of natural background radiation in the world and in this study, we aimed to evaluate the expression of MLH1 and MSH2 genes among the inhabitants of high background radiation areas of Ramsar compared to normal background radiation areas. In the present study, 60 blood sample from high and normal background inhabitants were collected and we MLH1, and MSH2 genes expressions in residents of high background radiation area compared with normal background radiation area were evaluated by Quantitative Real-Time PCR. Our results showed a significant upregulation of MLH1 in residents of high background radiation area. Also, there is a significant association between MLH1 and MSH2 gene expression in both sexes. Also, the increased expression of MLH1 in HBRA is notable. There is an increased expression of MLH1 in age above 50 and a decreased expression of MSH2 in ages under 50 years (P < 0.0001). These findings are suggesting the triggering of Mismatch Repair system in response to high-level of natural background radiation.
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Affiliation(s)
- Elahe Bakhtiari
- Student Research Committee, Babol University of Medical Sciences, Babol, I.R Iran; Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, I.R.Iran
| | - Ali Shabestani Monfared
- Cancer Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, I.R.Iran
| | - Hale Akhavan Niaki
- Department of Genetics, School of Medicine, Babol University of Medical Sciences, Babol, I.R Iran
| | - Sajad Borzoueisileh
- Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, I.R.Iran
| | - Fatemeh Niksirat
- Department of Medical Physics Radiobiology and Radiation Protection, School of Medicine, Babol University of Medical Sciences, Babol, I.R Iran
| | - Sadegh Fattahi
- Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, I.R.Iran; North Research Centre of Pasteur Institute, Amol, I.R.Iran
| | - Mohadese Kosari Monfared
- Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, I.R.Iran
| | - Kourosh Ebrahimnejad Gorji
- Department of Medical Physics Radiobiology and Radiation Protection, School of Medicine, Babol University of Medical Sciences, Babol, I.R Iran.
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7
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Tharmalingam S, Sreetharan S, Brooks AL, Boreham DR. Re-evaluation of the linear no-threshold (LNT) model using new paradigms and modern molecular studies. Chem Biol Interact 2019; 301:54-67. [PMID: 30763548 DOI: 10.1016/j.cbi.2018.11.013] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 11/13/2018] [Accepted: 11/22/2018] [Indexed: 02/06/2023]
Abstract
The linear no-threshold (LNT) model is currently used to estimate low dose radiation (LDR) induced health risks. This model lacks safety thresholds and postulates that health risks caused by ionizing radiation is directly proportional to dose. Therefore even the smallest radiation dose has the potential to cause an increase in cancer risk. Advances in LDR biology and cell molecular techniques demonstrate that the LNT model does not appropriately reflect the biology or the health effects at the low dose range. The main pitfall of the LNT model is due to the extrapolation of mutation and DNA damage studies that were conducted at high radiation doses delivered at a high dose-rate. These studies formed the basis of several outdated paradigms that are either incorrect or do not hold for LDR doses. Thus, the goal of this review is to summarize the modern cellular and molecular literature in LDR biology and provide new paradigms that better represent the biological effects in the low dose range. We demonstrate that LDR activates a variety of cellular defense mechanisms including DNA repair systems, programmed cell death (apoptosis), cell cycle arrest, senescence, adaptive memory, bystander effects, epigenetics, immune stimulation, and tumor suppression. The evidence presented in this review reveals that there are minimal health risks (cancer) with LDR exposure, and that a dose higher than some threshold value is necessary to achieve the harmful effects classically observed with high doses of radiation. Knowledge gained from this review can help the radiation protection community in making informed decisions regarding radiation policy and limits.
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Affiliation(s)
- Sujeenthar Tharmalingam
- Northern Ontario School of Medicine, Laurentian University, 935 Ramsey Lake Rd, Sudbury, ON, P3E 2C6, Canada.
| | - Shayenthiran Sreetharan
- Department of Medical Physics and Applied Radiation Sciences, McMaster University, 1280 Main Street W, Hamilton ON, L8S 4K1, Canada
| | - Antone L Brooks
- Environmental Science, Washington State University, Richland, WA, USA
| | - Douglas R Boreham
- Northern Ontario School of Medicine, Laurentian University, 935 Ramsey Lake Rd, Sudbury, ON, P3E 2C6, Canada; Bruce Power, Tiverton, ON(3), UK.
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8
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Olobatuyi O, de Vries G, Hillen T. Effects of G2-checkpoint dynamics on low-dose hyper-radiosensitivity. J Math Biol 2018; 77:1969-1997. [PMID: 29679122 DOI: 10.1007/s00285-018-1236-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 02/17/2018] [Indexed: 02/03/2023]
Abstract
In experimental studies, it has been found that certain cell lines are more sensitive to low-dose radiation than would be expected from the classical Linear-Quadratic model (LQ model). In fact, it is frequently observed that cells incur more damage at low dose (say 0.3 Gy) than at higher dose (say 1 Gy). This effect has been termed hyper-radiosensitivity (HRS). The effect depends on the type of cells and on their phase in the cell cycle when radiation is applied. Experiments have shown that the G2-checkpoint plays an important role in the HRS effects. Here we design and analyze a differential equation model for the cell cycle that includes G2-checkpoint dynamics and radiation treatment. We fit the model to surviving fraction data for different cell lines including glioma cells, prostate cancer cells, as well as to cell populations that are enriched in certain phases of the cell cycle. The HRS effect is measured in the literature through [Formula: see text], the ratio of slope [Formula: see text] of the surviving fraction curve at zero dose to slope [Formula: see text] of the corresponding LQ model. We derive an explicit formula for this ratio and we show that it corresponds very closely to experimental observations. Finally, we identify the dependence of this ratio on the surviving fraction at 2 Gy. It was speculated in the literature that such dependence exists. Our theoretical analysis will help to more systematically identify the HRS in cell lines, and opens doors to analyze its use in cancer treatment.
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Affiliation(s)
- Oluwole Olobatuyi
- Collaborative Mathematical Biology Group (formerly Center for Mathematical Biology), Department of Mathematical and Statistical Sciences, University of Alberta, Edmonton, AB, T6G 2G1, Canada.
| | - Gerda de Vries
- Collaborative Mathematical Biology Group (formerly Center for Mathematical Biology), Department of Mathematical and Statistical Sciences, University of Alberta, Edmonton, AB, T6G 2G1, Canada
| | - Thomas Hillen
- Collaborative Mathematical Biology Group (formerly Center for Mathematical Biology), Department of Mathematical and Statistical Sciences, University of Alberta, Edmonton, AB, T6G 2G1, Canada
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9
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Wang Q, Xiao Z, Lin Z, Zhou J, Chen W, Jie W, Cao X, Yin Z, Cheng J. Autophagy influences the low-dose hyper-radiosensitivity of human lung adenocarcinoma cells by regulating MLH1. Int J Radiat Biol 2017; 93:600-606. [PMID: 28117625 DOI: 10.1080/09553002.2017.1286052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
PURPOSE To investigate the impact of autophagy on the low-dose hyper-radiosensitivity (HRS) of human lung adenocarcinoma cells via MLH1 regulation. MATERIALS AND METHODS Immunofluorescent staining, Western blotting, and electron microscopy were utilized to detect autophagy in A549 and H460 cells. shRNA was used to silence MLH1 expression. The levels of MLH1, mTOR, p-mTOR, BNIP3, and Beclin-1 were measured by real-time polymerase chain reaction (PCR) and Western blotting. RESULTS A549 cells, which have low levels of MLH1 expression, displayed HRS/induced radioresistance (IRR). Conversely, the radiosensitivity of H460 cells, which express high levels of MLH1, conformed to the linear-quadratic (LQ) model. After down-regulating MLH1 expression, A549 cells showed increased HRS and inhibition of autophagy, whereas H460 cells exhibited HRS/IRR. The levels of mTOR, p-mTOR, and BNIP3 were reduced in cells harboring MLH1 shRNA, and the changes in the mTOR/p-mTOR ratio mirrored those in MLH1 expression. CONCLUSIONS Low MLH1-expressing A549 cells may exhibit HRS. Both the mTOR/p-mTOR and BNIP3/Beclin-1 signaling pathways were found to be related to HRS, but only mTOR/p-mTOR is involved in the regulation of HRS via MLH1 and autophagy.
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Affiliation(s)
- Qiong Wang
- a Cancer Center, Union Hospital , Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
| | - Zhuya Xiao
- a Cancer Center, Union Hospital , Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
| | - Zhenyu Lin
- a Cancer Center, Union Hospital , Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
| | - Jie Zhou
- a Cancer Center, Union Hospital , Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
| | - Weihong Chen
- a Cancer Center, Union Hospital , Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
| | - Wuyun Jie
- a Cancer Center, Union Hospital , Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
| | - Xing Cao
- a Cancer Center, Union Hospital , Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
| | - Zhongyuan Yin
- a Cancer Center, Union Hospital , Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
| | - Jing Cheng
- a Cancer Center, Union Hospital , Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
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10
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Functional role of DNA mismatch repair gene PMS2 in prostate cancer cells. Oncotarget 2016; 6:16341-51. [PMID: 26036629 PMCID: PMC4599273 DOI: 10.18632/oncotarget.3854] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 04/24/2015] [Indexed: 11/25/2022] Open
Abstract
DNA mismatch repair (MMR) enzymes act as proofreading complexes that maintains genomic integrity and MMR-deficient cells show an increased mutation rate. MMR has also been shown to influence cell signaling and the regulation of tumor development. MMR consists of various genes and includes post-meiotic segregation (PMS) 2 which is a vital component of mutL-alpha. In prostate, the functional role of this gene has never been reported and in this study, our aim was to investigate the effect of PMS2 on growth properties of prostate cancer (PCa) cells. Previous studies have shown PMS2 to be deficient in DU145 cells and this lack of expression was confirmed by Western blotting whereas normal prostatic PWR-1E and RWPE-1 cells expressed this gene. PMS2 effects on various growth properties of DU145 were then determined by creating stable gene transfectants. Interestingly, PMS2 caused decreased cell proliferation, migration, invasion, and in vivo growth; and increased apoptosis as compared to vector control. We further analyzed genes affected by PMS2 expression and observe the apoptosis-related TMS1 gene to be significantly upregulated whereas anti-apoptotic BCL2A1 was downregulated. These results demonstrate a functional role for PMS2 to protect against PCa progression by enhancing apoptosis of PCa cells.
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11
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Fernandez-Palomo C, Seymour C, Mothersill C. Inter-Relationship between Low-Dose Hyper-Radiosensitivity and Radiation-Induced Bystander Effects in the Human T98G Glioma and the Epithelial HaCaT Cell Line. Radiat Res 2016; 185:124-33. [PMID: 26849405 DOI: 10.1667/rr14208.1] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Over the past several years, investigations in both low-dose hyper-radiosensitivity and increased radioresistance have been a focus of radiation oncology and biology research, since both conditions occur primarily in tumor cell lines. There has been significant progress in elucidating their signaling pathways, however uncertainties exist when they are studied together with radiation-induced bystander effects. Therefore, the aim of this work was to further investigate this relationship using the T98G glioma and HaCaT cell lines. T98G glioma cells have demonstrated a strong transition from hyper-radiosensitivity to induced radioresistance, and HaCaT cells do not show low-dose hypersensitivity. Both cell lines were paired using a mix-and-match protocol, which involved growing nonirradiated cells in culture media from irradiated cells and covering all possible combinations between them. The end points analyzed were clonogenic cell survival and live calcium measurements through the cellular membrane. Our data demonstrated that T98G cells produced bystander signals that decreased the survival of both reporter T98G and HaCaT cells. The bystander effect occurred only when T98G cells were exposed to doses below 1 Gy, which was corroborated by the induction of calcium fluxes. However, when bystander signals originated from HaCaT cells, the survival fraction increased in reporter T98G cells while it decreased in HaCaT cells. Moreover, the corresponding calcium data showed no calcium fluxes in T98G cells, while HaCaT cells displayed a biphasic calcium profile. In conclusion, our findings indicate a possible link between low-dose hyper-radiosensitivity and bystander effects. This relationship varies depending on which cell line functions as the source of bystander signals. This further suggests that the bystander mechanisms are more complex than previously expected and caution should be taken when extrapolating bystander results across all cell lines and all radiation doses.
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Affiliation(s)
- Cristian Fernandez-Palomo
- Medical Physics and Applied Radiation Sciences Department, McMaster University, Hamilton, Ontario, L8S 1K4, Canada
| | - Colin Seymour
- Medical Physics and Applied Radiation Sciences Department, McMaster University, Hamilton, Ontario, L8S 1K4, Canada
| | - Carmel Mothersill
- Medical Physics and Applied Radiation Sciences Department, McMaster University, Hamilton, Ontario, L8S 1K4, Canada
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Targeting Mismatch Repair defects: A novel strategy for personalized cancer treatment. DNA Repair (Amst) 2016; 38:135-139. [DOI: 10.1016/j.dnarep.2015.11.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 09/08/2015] [Accepted: 11/30/2015] [Indexed: 11/21/2022]
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Balderson M, Koger B, Kirkby C. The relative biological effectiveness of out-of-field dose. Phys Med Biol 2016; 61:114-30. [PMID: 26611151 DOI: 10.1088/0031-9155/61/1/114] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE using simulations and models derived from existing literature, this work investigates relative biological effectiveness (RBE) for out-of-field radiation and attempts to quantify the relative magnitudes of different contributing phenomena (spectral, bystander, and low dose hypersensitivity effects). Specific attention is paid to external beam radiotherapy treatments for prostate cancer. MATERIALS AND METHODS using different biological models that account for spectral, bystander, and low dose hypersensitivity effects, the RBE was calculated for different points moving radially out from isocentre for a typical single arc VMAT prostate case. The RBE was found by taking the ratio of the equivalent dose with the physical dose. Equivalent doses were calculated by determining what physical dose would be necessary to produce the same overall biological effect as that predicted using the different biological models. RESULTS spectral effects changed the RBE out-of-field less than 2%, whereas response models incorporating low dose hypersensitivity and bystander effects resulted in a much more profound change of the RBE for out-of-field doses. The bystander effect had the largest RBE for points located just outside the edge of the primary radiation beam in the cranial caudal (z-direction) compared to low dose hypersensitivity and spectral effects. In the coplanar direction, bystander effect played the largest role in enhancing the RBE for points up to 8.75 cm from isocentre. CONCLUSIONS spectral, bystander, and low dose hypersensitivity effects can all increase the RBE for out-of-field radiation doses. In most cases, bystander effects seem to play the largest role followed by low dose hypersensitivity. Spectral effects were unlikely to be of any clinical significance. Bystander, low dose hypersensitivity, and spectral effect increased the RBE much more in the cranial caudal direction (z-direction) compared with the coplanar directions.
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Affiliation(s)
- Michael Balderson
- Department of Medical Physics, Jack Ady Cancer Center, Lethbridge, Alberta, Canada. Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
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Meade AD, Howe O, Unterreiner V, Sockalingum GD, Byrne HJ, Lyng FM. Vibrational spectroscopy in sensing radiobiological effects: analyses of targeted and non-targeted effects in human keratinocytes. Faraday Discuss 2016; 187:213-34. [DOI: 10.1039/c5fd00208g] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Modern models of radiobiological effects include mechanisms of damage initiation, sensing and repair, for those cells that directly absorb ionizing radiation as well as those that experience molecular signals from directly irradiated cells. In the former case, the effects are termed targeted effects while, in the latter, non-targeted effects. It has emerged that phenomena occur at low doses below 1 Gy in directly irradiated cells that are associated with cell-cycle-dependent mechanisms of DNA damage sensing and repair. Likewise in non-targeted bystander-irradiated cells the effect saturates at 0.5 Gy. Both effects at these doses challenge the limits of detection of vibrational spectroscopy. In this paper, a study of the sensing of both targeted and non-targeted effects in HaCaT human keratinocytes irradiated with gamma ray photons is conducted with vibrational spectroscopy. In the case of directly irradiated cells, it is shown that the HaCaT cell line does exhibit both hyperradiosensitivity and increased radioresistance at low doses, a transition between the two effects occurring at a dose of 200 mGy, and that cell survival and other physiological effects as a function of dose follow the induced repair model. Both Raman and FTIR signatures are shown to follow a similar model, suggesting that the spectra include signatures of DNA damage sensing and repair. In bystander-irradiated cells, pro- and anti-apoptotic signalling and mechanisms of ROS damage were inhibited in the mitogen-activated protein kinase (MAPK) transduction pathway. It is shown that Raman spectral profiles of bystander-irradiated cells are correlated with markers of bystander signalling and molecular transduction. This work demonstrates for the first time that both targeted and non-targeted effects of ionizing radiation damage are detected by vibrational spectroscopy in vitro.
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Affiliation(s)
- Aidan D. Meade
- School of Physics
- Dublin Institute of Technology
- Dublin 8
- Ireland
- DIT Centre for Radiation and Environmental Science
| | - Orla Howe
- DIT Centre for Radiation and Environmental Science
- Focas Research Institute
- Dublin Institute of Technology
- Dublin 8
- Ireland
| | - Valérie Unterreiner
- Plateforme en Imagerie Cellulaire et Tissulaire (PICT)
- Université de Reims Champagne-Ardenne
- 51095 Reims Cedex
- France
| | - Ganesh D. Sockalingum
- Université de Reims Champagne-Ardenne
- MéDIAN-Biophotonique et Technologies pour la Santé
- UFR de Pharmacie
- 51095 Reims Cedex
- France
| | - Hugh J. Byrne
- Focas Research Institute
- Dublin Institute of Technology
- Dublin 8
- Ireland
| | - Fiona M. Lyng
- School of Physics
- Dublin Institute of Technology
- Dublin 8
- Ireland
- DIT Centre for Radiation and Environmental Science
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Słonina D, Gasińska A, Biesaga B, Janecka A, Kabat D. An association between low-dose hyper-radiosensitivity and the early G2-phase checkpoint in normal fibroblasts of cancer patients. DNA Repair (Amst) 2015; 39:41-5. [PMID: 26725161 DOI: 10.1016/j.dnarep.2015.12.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 12/11/2015] [Accepted: 12/11/2015] [Indexed: 10/22/2022]
Abstract
In our previous study, low-dose hyper-radiosensitivity (HRS) effect was demonstrated for normal fibroblasts (asynchronous and G2-phase enriched) of 4 of the 25 cancer patients investigated. For the rest of patients, HRS was not defined in either of the 2 fibroblast populations. Thus, the study indicated that G2-phase enrichment had no influence on HRS identification. The conclusion contradicts that reported for human tumor cells, and suggests different mechanism of HRS in normal human cells. In the present paper we report, for the first time, the activity of early G2-phase checkpoint after low-dose irradiation in normal fibroblasts of these 4 HRS-positive patients and 4 HRS-negative patients and answer the question regarding the role of this checkpoint in normal human cells. The response of the early G2-phase checkpoint was determined by assessment of the progression of irradiated cells into mitosis using the mitotic marker, phosphorylated histone H3. We found evident differences in the activity of the early G2-phase checkpoint between HRS-positive and HRS-negative fibroblasts. In HRS-positive fibroblasts the checkpoint was not triggered and DNA damage was not recognized after doses lower than 0.2Gy resulting in HRS response. On the contrary, in HRS-negative fibroblasts the early G2-phase checkpoint was activated regardless of the dose in the range 0.1-2Gy. In conclusion, although cell cycle phase has no effect on the presence of HRS effect in normal human fibroblasts, the data reported here indicate that HRS response in these cells is associated with the functioning of early G2-phase checkpoint in a threshold-dose dependent manner, similarly as it takes place in most of human tumor and other cells.
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Affiliation(s)
- Dorota Słonina
- Department of Applied Radiobiology, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology Cracow Branch, 11 Garncarska Street, Cracow 31-115, Poland.
| | - Anna Gasińska
- Department of Applied Radiobiology, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology Cracow Branch, 11 Garncarska Street, Cracow 31-115, Poland
| | - Beata Biesaga
- Department of Applied Radiobiology, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology Cracow Branch, 11 Garncarska Street, Cracow 31-115, Poland
| | - Anna Janecka
- Department of Applied Radiobiology, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology Cracow Branch, 11 Garncarska Street, Cracow 31-115, Poland
| | - Damian Kabat
- Department of Medical Physics, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology Cracow Branch, 11 Garncarska Street, Cracow 31-115, Poland
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Martin LM, Marples B, Lynch TH, Hollywood D, Marignol L. Exposure to low dose ionising radiation: Molecular and clinical consequences. Cancer Lett 2014; 349:98-106. [DOI: 10.1016/j.canlet.2013.12.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Hornhardt S, Rößler U, Sauter W, Rosenberger A, Illig T, Bickeböller H, Wichmann HE, Gomolka M. Genetic factors in individual radiation sensitivity. DNA Repair (Amst) 2014; 16:54-65. [PMID: 24674628 DOI: 10.1016/j.dnarep.2014.02.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 01/31/2014] [Accepted: 02/01/2014] [Indexed: 01/04/2023]
Abstract
Cancer risk and radiation sensitivity are often associated with alterations in DNA repair, cell cycle, or apoptotic pathways. Interindividual variability in mutagen or radiation sensitivity and in cancer susceptibility may also be traced back to polymorphisms of genes affecting e.g. DNA repair capacity. We studied possible associations between 70 polymorphisms of 12 DNA repair genes with basal and initial DNA damage and with repair thereof. We investigated DNA damage induced by ionizing radiation in lymphocytes isolated from 177 young lung cancer patients and 169 cancer-free controls. We also sought replication of our findings in an independent sample of 175 families (in total 798 individuals). DNA damage was assessed by the Olive tail moment (OTM) of the comet assay. DNA repair capacity (DRC) was determined for 10, 30 and, 60min of repair. Genes involved in the single-strand-repair pathway (SSR; like XRCC1 and MSH2) as well as genes involved in the double-strand-repair pathway (DSR; like RAD50, XRCC4, MRE11 and ATM) were found to be associated with DNA damage. The most significant association was observed for marker rs3213334 (p=0.005) of XRCC1 with basal DNA damage (B), in both cases and controls. A clear additive effect on the logarithm of OTM was identified for the marker rs1001581 of the same LD-block (p=0.039): BCC=-1.06 (95%-CI: -1.16 to -0.96), BCT=-1.02 (95%-CI: -1.11 to -0.93) and BTT=-0.85 (95%-CI: -1.01 to -0.68). In both cases and controls, we observed significantly higher DNA basal damage (p=0.007) for carriers of the genotype AA of marker rs2237060 of RAD50 (involved in DSR). However, this could not be replicated in the sample of families (p=0.781). An alteration to DRC after 30min of repair with respect to cases was observed as borderline significant for marker rs611646 of ATM (involved in DSR; p=0.055), but was the most significant finding in the sample of families (p=0.009). Our data indicate that gene variation impacts measurably on DNA damage and repair, suggesting at least a partial contribution to radiation sensitivity and lung cancer susceptibility.
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Affiliation(s)
- Sabine Hornhardt
- Department of Radiation Protection and Health, Federal Office for Radiation Protection, Ingolstaedter Landstr.1, 85764 Oberschleissheim,Germany.
| | - Ute Rößler
- Department of Radiation Protection and Health, Federal Office for Radiation Protection, Ingolstaedter Landstr.1, 85764 Oberschleissheim,Germany.
| | - Wiebke Sauter
- Institute of Epidemiology, Helmholtz Center Munich, 85764 Neuherberg, Germany.
| | - Albert Rosenberger
- Department of Genetic Epidemiology, University Medical Center, Georg-August-University Göttingen, 37073 Göttingen, Germany.
| | - Thomas Illig
- Institute of Epidemiology, Helmholtz Center Munich, 85764 Neuherberg, Germany.
| | - Heike Bickeböller
- Department of Genetic Epidemiology, University Medical Center, Georg-August-University Göttingen, 37073 Göttingen, Germany.
| | - Hans-Erich Wichmann
- Institute of Epidemiology, Helmholtz Center Munich, 85764 Neuherberg, Germany; Department of Medical Informatics, Biometry and Epidemiology, Ludwig-Maximilians-University Munich, 80539 Munich, Germany.
| | - Maria Gomolka
- Department of Radiation Protection and Health, Federal Office for Radiation Protection, Ingolstaedter Landstr.1, 85764 Oberschleissheim,Germany.
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Słonina D, Biesaga B, Janecka A, Kabat D, Bukowska-Strakova K, Gasińska A. Low-Dose Hyper-Radiosensitivity Is Not a Common Effect in Normal Asynchronous and G2-Phase Fibroblasts of Cancer Patients. Int J Radiat Oncol Biol Phys 2014; 88:369-76. [DOI: 10.1016/j.ijrobp.2013.10.031] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 10/21/2013] [Accepted: 10/22/2013] [Indexed: 11/17/2022]
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Martin LM, Marples B, Davies AM, Atzberger A, Edwards C, Lynch TH, Hollywood D, Marignol L. DNA mismatch repair protein MSH2 dictates cellular survival in response to low dose radiation in endometrial carcinoma cells. Cancer Lett 2013; 335:19-25. [DOI: 10.1016/j.canlet.2013.01.046] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Revised: 01/24/2013] [Accepted: 01/24/2013] [Indexed: 11/24/2022]
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Thomas C, Martin J, Devic C, Bräuer-Krisch E, Diserbo M, Thariat J, Foray N. Impact of dose-rate on the low-dose hyper-radiosensitivity and induced radioresistance (HRS/IRR) response. Int J Radiat Biol 2013; 89:813-22. [PMID: 23631649 DOI: 10.3109/09553002.2013.800248] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
PURPOSE To ask whether dose-rate influences low-dose hyper- radiosensitivity and induced radioresistance (HRS/IRR) response in rat colon progressive (PRO) and regressive (REG) cells. METHODS Clonogenic survival was applied to tumorigenic PRO and non-tumorigenic REG cells irradiated with (60)Co γ-rays at 0.0025-500 mGy.min(-1). Both clonogenic survival and non-homologous end-joining (NHEJ) pathway involved in DNA double-strand breaks (DSB) repair assays were applied to PRO cells irradiated at 25 mGy.min(-1) with 75 kV X-rays only. RESULTS Irrespective of dose-rates, marked HRS/IRR responses were observed in PRO but not in REG cells. For PRO cells, the doses at which HRS and IRR responses are maximal were dependent on dose-rate; conversely exposure times during which HRS and IRR responses are maximal (t(HRSmax) and t(IRRmax)) were independent of dose-rate. The t(HRSmax) and t(IRRmax) values were 23 ± 5 s and 66 ± 7 s (mean ± standard error of the mean [SEM], n = 7), in agreement with literature data. Repair data show that t(HRSmax) may correspond to exposure time during which NHEJ is deficient while t(IRRmax) may correspond to exposure time during which NHEJ is complete. CONCLUSION HRS response may be maximal if exposure times are shorter than t(HRSmax) irrespective of dose, dose-rate and cellular model. Potential application of HRS response in radiotherapy is discussed.
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Affiliation(s)
- Charles Thomas
- Institut National de la Santé et de la Recherche Médicale (INSERM) U 1052, groupe de radiobiologie , Lyon
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21
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Exposure to low dose ionising radiation: molecular and clinical consequences. Cancer Lett 2013; 338:209-18. [PMID: 23693079 DOI: 10.1016/j.canlet.2013.05.021] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Revised: 05/10/2013] [Accepted: 05/13/2013] [Indexed: 12/19/2022]
Abstract
This review article provides a comprehensive overview of the experimental data detailing the incidence, mechanism and significance of low dose hyper-radiosensitivity (HRS). Important discoveries gained from past and present studies are mapped and highlighted to illustrate the pathway to our current understanding of HRS and the impact of HRS on the cellular response to radiation in mammalian cells. Particular attention is paid to the balance of evidence suggesting a role for DNA repair processes in the response, evidence suggesting a role for the cell cycle checkpoint processes, and evidence investigating the clinical implications/relevance of the effect.
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Guirado D, Aranda M, Ortiz M, Mesa JA, Zamora LI, Amaya E, Villalobos M, Lallena AM. Low-dose radiation hyper-radiosensitivity in multicellular tumour spheroids. Br J Radiol 2012; 85:1398-406. [PMID: 22972973 DOI: 10.1259/bjr/33201506] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE We propose and study a new model aimed at describing the low-dose hyper-radiosensitivity phenomenon appearing in the survival curves of different cell lines. METHODS The model uses the induced repair assumption, considering that the critical dose at which this mechanism begins to act varies from cell to cell in a given population. The model proposed is compared with the linear-quadratic model and the modified linear-quadratic model, which is commonly used in literature and in which the induced repair is taken into account in a heuristic way. The survival curve for the MCF-7 line of human breast cancer is measured at low absorbed doses and the uncertainties in these doses are estimated using thermoluminiscent dosemeters. RESULTS It is shown that these multicellular spheroids present low-dose hyper-radiosensitivity. The new model permits an accurate description of the data of two human cell lines (previously published) and of the multicellular spheroids of the MCF-7 line here measured. CONCLUSION The model shows enough flexibility to account for data with very different characteristics and considers in a faithful way the hypothesis of the repair induction.
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Affiliation(s)
- D Guirado
- Radiophysics Service, University Hospital San Cecilio, Granada, Spain
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Low-dose fractionated radiation with induction chemotherapy for locally advanced head and neck cancer: 5 year results of a prospective phase II trial. ACTA ACUST UNITED AC 2012; 2:35-42. [PMID: 26052405 DOI: 10.1007/s13566-012-0074-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
OBJECTIVE This study aims to report the long-term outcomes of a novel treatment approach utilizing induction low-dose fractionated radiation therapy (LDFRT) and chemotherapy for locally advanced squamous cell carcinoma of head and neck (SCCHN). METHODS We prospectively enrolled 40 patients with locally advanced SCCHN (77 % stage IV) on a phase II clinical trial and treated with induction paclitaxel (225 mg/m2), carboplatin (AUC 6), and LDFRT (80 cGy BID on days 1 and 2) every 21 days for two cycles. RESULTS Forty patients enrolled; 39 were evaluable. The acute toxicity and response data have been previously reported; overall response rate (RR) was 82 %. After induction, definitive therapy was concurrent chemoradiation (CRT) in 51 %, XRT alone in 39 %, surgery in 5 %, and surgery and XRT in 5 %. The long-term outcomes are now reported with a median follow-up of 83 months. Locoregional control (LRC) is 80 % and distant control (DC) is 77 %. Five-year overall survival (OS), disease-specific survival, and progression-free survival (PFS) are 62 %, 66 %, and 58 %, respectively. CONCLUSION Induction chemotherapy with LDFRT has a high initial RR, comparable toxicity to two-drug induction regimens, but adds a third novel and effective agent, LDFRT. Five-year follow-up shows favorable outcomes compared to historical controls and excellent compliance with definitive therapy. This novel treatment approach is now planned for phase 3 trial evaluation.
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Aberrant methylation of different DNA repair genes demonstrates distinct prognostic value for esophageal cancer. Dig Dis Sci 2011; 56:2992-3004. [PMID: 21674174 DOI: 10.1007/s10620-011-1774-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Accepted: 05/30/2011] [Indexed: 01/25/2023]
Abstract
BACKGROUND DNA mismatch repair (MMR) deficiency results in a strong mutator phenotype and high-frequency microsatellite instability (MSI-H), which are the hallmarks of many tumors. AIM The objective of this study is to investigate the promoter CpG island methylation status of mismatch repair genes human mutL homolog 1 (hMLH1), human mutS homolog 2 (hMSH2), and O(6)-methylguanine-DNA methyltransferase (MGMT) in esophageal squamous cell carcinoma (ESCC) and its roles in alkylating agents chemotherapy. METHODS Real-time methylation-specific polymerase chain reaction (PCR) (real-time MSP) was employed to detect promoter CpG island methylation of the hMLH1, hMSH2, as well as MGMT genes in 235 surgical tumor tissue samples from ESCC patients and their corresponding normal tissue samples. RESULTS Promoter CpG island methylation of hMLH1, hMSH2, and MGMT were detectable in 43.4, 28.9, and 40.4% of ESCC tumor DNA, respectively, and the loss rates of hMLH1, hMSH2, and MGMT protein expression were 48.6, 34.5, and 40.9% in tumor tissues, respectively. For the entire population of 235 ESCC patients who were enrolled in operating treatment combined with radiotherapy and chemotherapy with alkylating agents, there was a significant difference in the overall survival between patients with methylated MGMT promoter and those with an unmethylated MGMT promoter (P < 0.05). CONCLUSION Promoter CpG island methylation may be a frequent event in ESCC carcinogenesis. Detection of the methylated sequences of hMLH1, hMSH2, and MGMT appears to be promising as a predictive factor in primary ESCC.
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Soni A, Bansal A, Singh L, Mishra AK, Majumdar M, Regina T, Mohanty N, Saxena S. Gene Expression Profile and Mutational Analysis of DNA Mismatch Repair Genes in Carcinoma Prostate in Indian Population. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2011; 15:319-24. [DOI: 10.1089/omi.2010.0110] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Abha Soni
- Institute of Pathology, Indian Council of Medical Research, Tumour Biology, New Delhi, India
| | - Anju Bansal
- Institute of Pathology, Indian Council of Medical Research, Tumour Biology, New Delhi, India
| | - L.C. Singh
- Institute of Pathology, Indian Council of Medical Research, Tumour Biology, New Delhi, India
| | - Ashwani K. Mishra
- Institute of Pathology, Indian Council of Medical Research, Tumour Biology, New Delhi, India
| | | | - Thoudam Regina
- Institute of Pathology, Indian Council of Medical Research, Tumour Biology, New Delhi, India
| | - N.K. Mohanty
- Safdarjung Hospital and VMMC, Department of Urology, New Delhi, India
| | - Sunita Saxena
- Institute of Pathology, Indian Council of Medical Research, Tumour Biology, New Delhi, India
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Martin LM, Marples B, Coffey M, Lawler M, Lynch TH, Hollywood D, Marignol L. DNA mismatch repair and the DNA damage response to ionizing radiation: Making sense of apparently conflicting data. Cancer Treat Rev 2010; 36:518-27. [PMID: 20413225 DOI: 10.1016/j.ctrv.2010.03.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2010] [Revised: 03/12/2010] [Accepted: 03/21/2010] [Indexed: 10/19/2022]
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27
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DNA mismatch repair and the transition to hormone independence in breast and prostate cancer. Cancer Lett 2009; 291:142-9. [PMID: 19896265 DOI: 10.1016/j.canlet.2009.10.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2009] [Revised: 09/23/2009] [Accepted: 10/09/2009] [Indexed: 02/07/2023]
Abstract
The molecular basis for the progression of breast and prostate cancer from hormone dependent to hormone independent disease remains a critical issue in the management of these two cancers. The DNA mismatch repair system is integral to the maintenance of genomic stability and suppression of tumorigenesis. No firm consensus exists regarding the implications of mismatch repair (MMR) deficiencies in the development of breast or prostate cancer. However, recent studies have reported an association between mismatch repair deficiency and loss of specific hormone receptors, inferring a potential role for mismatch repair deficiency in this transition. An updated review of the experimental data supporting or contradicting the involvement of MMR defects in the development and progression of breast and prostate cancer will be provided with particular emphasis on their implications in the transition to hormone independence.
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