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Jain V, Saini D, Soren DC, Kumar VA, Vivek Kumar PR, Koya PKM, Jaikrishan G, Das B. Non-linear dose response of DNA double strand breaks in response to chronic low dose radiation in individuals from high level natural radiation areas of Kerala coast. Genes Environ 2023; 45:16. [PMID: 37127760 PMCID: PMC10150514 DOI: 10.1186/s41021-023-00273-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 04/06/2023] [Indexed: 05/03/2023] Open
Abstract
BACKGROUND The human population living in high level natural radiation areas (HLNRAs) of Kerala coast provide unique opportunities to study the biological effects of low dose and low dose rate ionizing radiation below 100 mGy. The level of radiation in this area varies from < 1.0 to 45 mGy/year. The areas with ≤ 1.50 mGy/year are considered as normal level natural radiation areas (NLNRA) and > 1.50 mGy/year, as high level natural radiation areas (HLNRA). The present study evaluated dose response relationship between DNA double strand breaks (DSBs) and background radiation dose in individuals residing in Kerala coast. Venous blood samples were collected from 200 individuals belonging to NLNRA (n = 50) and four dose groups of HLNRA; 1.51-5.0 mGy/year (n = 50), 5.01-10.0 mGy/year (n = 30), 10.01-15.0 mGy/year (n = 33), > 15.0 mGy/year (n = 37) with written informed consent. The mean dose of NLNRA and four HLNRA dose groups studied are 1.21 ± 0.21 (range: 0.57-1.49), 3.02 ± 0.95 (range: 1.57-4.93), 7.43 ± 1.48 (range: 5.01-9.75), 12.22 ± 1.47 (range: 10.21-14.99), 21.64 ± 6.28 (range: 15.26-39.88) mGy/year, respectively. DNA DSBs were quantified using γH2AX as a marker, where foci were counted per cell using fluorescence microscopy. RESULTS Our results revealed that the frequency of γH2AX foci per cell was 0.090 ± 0.051 and 0.096 ± 0.051, respectively in NLNRA and HLNRA individuals, which were not significantly different (t198 = 0.33; P = 0.739). The frequency of γH2AX foci was observed to be 0.090 ± 0.051, 0.096 ± 0.051, 0.076 ± 0.036, 0.087 ± 0.042, 0.108 ± 0.046 per cell, respectively in different dose groups of ≤ 1.50, 1.51-5.0, 5.01-10.0, 10.01-15.0, > 15.0mGy/year (ANOVA, F4,195 = 2.18, P = 0.072) and suggested non-linearity in dose response. The frequency of γH2AX foci was observed to be 0.098 ± 0.042, 0.078 ± 0.037, 0.084 ± 0.042, 0.099 ± 0.058, 0.097 ± 0.06 and 0.114 ± 0.033 per cell in the age groups of ≤ 29, 30-34, 35-39, 40-44, 45-49 and ≥ 50 years, respectively (ANOVA, F5,194 = 2.17, P = 0.059), which suggested marginal influence of age on the baseline of DSBs. Personal habits such as smoking (No v/s Yes: 0.092 ± 0.047 v/s 0.093 ± 0.048, t198 = 0.13; P = 0.895) and drinking alcohol (No v/s Yes: 0.096 ± 0.052 v/s 0.091 ± 0.045, t198 = 0.62; P = 0.538) did not show any influence on DSBs in the population. CONCLUSION The present study did not show any increase in DSBs in different dose groups of HLNRA compared to NLNRA, however, it suggested a non-linear dose response between DNA DSBs and chronic low dose radiation.
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Affiliation(s)
- Vinay Jain
- Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Sciences Group (BSG), Bhabha Atomic Research Centre (BARC), Trombay, Mumbai, 400 085, India
- Homi Bhabha National Institute (HBNI), Anushakti Nagar, Trombay, Mumbai, 400 094, India
| | - Divyalakshmi Saini
- Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Sciences Group (BSG), Bhabha Atomic Research Centre (BARC), Trombay, Mumbai, 400 085, India
| | - D C Soren
- Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Sciences Group (BSG), Bhabha Atomic Research Centre (BARC), Trombay, Mumbai, 400 085, India
| | - V Anil Kumar
- Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Sciences Group (BSG), Bhabha Atomic Research Centre (BARC), Trombay, Mumbai, 400 085, India
| | - P R Vivek Kumar
- Low Level Radiation Research Laboratory, LLRRS, RB&HSD, BSG, BARC, IRE Campus, Beach Road, Kollam, Kerala, 691 001, India
- Homi Bhabha National Institute (HBNI), Anushakti Nagar, Trombay, Mumbai, 400 094, India
| | - P K M Koya
- Low Level Radiation Research Laboratory, LLRRS, RB&HSD, BSG, BARC, IRE Campus, Beach Road, Kollam, Kerala, 691 001, India
| | - G Jaikrishan
- Low Level Radiation Research Laboratory, LLRRS, RB&HSD, BSG, BARC, IRE Campus, Beach Road, Kollam, Kerala, 691 001, India
| | - Birajalaxmi Das
- Low Level Radiation Research Section (LLRRS), Radiation Biology & Health Sciences Division (RB&HSD), Bio-Sciences Group (BSG), Bhabha Atomic Research Centre (BARC), Trombay, Mumbai, 400 085, India.
- Homi Bhabha National Institute (HBNI), Anushakti Nagar, Trombay, Mumbai, 400 094, India.
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Saini D, Jain V, Das B. Evaluation of natural chronic low dose radiation exposure on telomere length and transcriptional response of shelterin complex in individuals residing in Kerala coast, India. Mutat Res 2022; 825:111797. [PMID: 36116241 DOI: 10.1016/j.mrfmmm.2022.111797] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 08/16/2022] [Accepted: 08/23/2022] [Indexed: 06/15/2023]
Abstract
The high level natural radiation areas (HLNRA) of Kerala coast provide unique opportunity to study the biological effect of chronic low dose ionizing radiation (LDIR) on human population below 100 mSv. The radiation level in this area varies from < 1.0-45 mGy /year due to patchy distribution of monazite in the sand, which contains 232Th (8-10%), 238U (0.3%), and their decay products. Telomere length attrition has been correlated to DNA damage due to genotoxic agents. The objective of the present study is to evaluate the effect of natural chronic LDIR exposure on telomere length and transcriptional response of telomere specific and DNA damage repair genes in peripheral blood mononuclear cells (PBMCs) of individuals from normal level natural radiation areas (NLNRA) and HLNRA of Kerala coast, southwest India. Blood samples were collected from 71 random male donors (24-80 years) from NLNRA (≤1.50 mGy/year; N = 19) and two HLNRA dose groups [1.51-10 mGy/year (N = 17); > 10 mGy/year, (N = 35)]. Genomic DNA was isolated from PBMCs and relative telomere length (RTL) was determined using real time q-PCR. Radio-adaptive response (RAR) study was carried out in PBMCs of 40 random males from NLNRA (N = 20) and HLNRA (>10 mGy/year; N = 20), where PBMCs were given a challenged dose of 2.0 Gy gamma radiation at 4 h. Transcriptional profile of telomere specific (TRF1, TRF2, POT1, TIN2, TPP1, RAP1), DNA damage response (RAD17, ATM, CHEK1) and base excision repair pathway (BER) (OGG1, XRCC1, NTH1, NEIL1, MUTYH, MBD4) genes were analysed at basal level and after a challenge dose of 2.0 Gy at 4 h. Our results did not show any significant effect of chronic LDR on RTL among the individuals from NLNRA and two HLNRA groups (p = 0.195). However, influence of age on RTL was clearly evident among NLNRA and HLNRA individuals. At basal level, TRF1, TRF2, TIN2, MBD4, NEIL1 and RAD17 showed significant up-regulation, whereas XRCC1 was significantly down regulated in HLNRA individuals. After a challenge dose of 2.0 Gy, significant transcriptional up-regulation was observed at telomere specific (TRF2, POT1) and BER (MBD4, NEIL1) genes in HLNRA individuals as compared to NLNRA suggesting their role in RAR. In conclusion, elevated level of natural chronic LDR exposure did not have any adverse effect on telomere length in Kerala coast. Significant transcriptional response at TRF2, MBD4 and NEIL1 at basal level and with a challenge dose of 2.0 Gy suggested their active involvement in efficient repair and telomere maintenance in individuals from HLNRA of Kerala coast.
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Affiliation(s)
- Divyalakshmi Saini
- Low Level Radiation Research Section, Radiation Biology & Health Sciences Division, Bio-Sciences Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India; Mumbai University, Fort Mumbai, India
| | - Vinay Jain
- Low Level Radiation Research Section, Radiation Biology & Health Sciences Division, Bio-Sciences Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India; Homi Bhabha National Institute (HBNI), Anushakti Nagar, Trombay, Mumbai 400 094, India
| | - Birajalaxmi Das
- Low Level Radiation Research Section, Radiation Biology & Health Sciences Division, Bio-Sciences Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India; Mumbai University, Fort Mumbai, India; Homi Bhabha National Institute (HBNI), Anushakti Nagar, Trombay, Mumbai 400 094, India.
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Wang Z, He S, Jiang M, Li X, Chen N. Mechanism Study on Radiosensitization Effect of Curcumin in Bladder Cancer Cells Regulated by Filamin A. Dose Response 2022; 20:15593258221100997. [PMID: 35677349 PMCID: PMC9168873 DOI: 10.1177/15593258221100997] [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] [Indexed: 11/17/2022] Open
Abstract
Objective To study the radiosensitization effect of curcumin, a natural product with
anti-inflammatory and anti-cancer properties, in bladder cancer cells and identify the
specific role of FLNA gene in that process. Methods CCK-8 method was initially adopted to identify the proper interventional concentration
of curcumin. T24 bladder cancer cells were subjected to CCK-8, flow cytometry, and
colony formation assay to study the cell biological behaviors under different
interventions. γ-H2AX test was performed to test the level of damage in T24 cells.
RT-qPCR and Western blot were conducted to measure FLNA mRNA and protein levels. Results Low-dose curcumin (10, 20 μM) following X-ray exposure resulted in increased DNA
damage, augmented apoptosis, and reduced proliferation of T24 cells. Certain
radiosensitization was demonstrated when curcumin was applied at 10 μM. Additionally,
elevation of FLNA gene and protein levels was also indicated upon combination
treatment. Conclusion Low-dose curcumin has certain radiosensitization effect in bladder cancer, where FLNA
plays a certain regulatory role.
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Affiliation(s)
- Zhenfan Wang
- Soochow University Affiliated Suzhou Ninth Hospital, Suzhou, China
| | - Shuqing He
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, China
- School of Public Health, Medical College of Soochow University, Suzhou, China
| | - Minjun Jiang
- Soochow University Affiliated Suzhou Ninth Hospital, Suzhou, China
| | - Xue Li
- Soochow University Affiliated Suzhou Ninth Hospital, Suzhou, China
| | - Na Chen
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, China
- Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, China
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Ghosh A. Biological and cellular responses of humans to high-level natural radiation: A clarion call for a fresh perspective on the linear no-threshold paradigm. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2022; 878:503478. [PMID: 35649671 DOI: 10.1016/j.mrgentox.2022.503478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 03/04/2022] [Accepted: 03/04/2022] [Indexed: 06/15/2023]
Abstract
There remains considerable uncertainty in obtaining risk estimates of adverse health outcomes of chronic low-dose radiation. In the absence of reliable direct data, extrapolation through the linear no-threshold (LNT) hypothesis forms the cardinal tenet of all risk assessments for low doses (≤ 100 mGy) and for the radiation protection principle of As Low As Reasonably Achievable (ALARA). However, as recent evidences demonstrate, LNT assumptions do not appropriately reflect the biology of the cell at the low-dose end of the dose-response curve. In this regard, human populations living in high-level natural radiation areas (HLNRA) of the world can provide valuable insights into the biological and cellular effects of chronic radiation to facilitate improved precision of the dose-response relationship at low doses. Here, data obtained over decades of epidemiological and radiobiological studies on HLNRA populations is summarized. These studies do not show any evidence of unfavourable health effects or adverse cellular effects that can be correlated with high-level natural radiation. Contrary to the assumptions of LNT, no excess cancer risks or untoward pregnancy outcomes have been found to be associated with cumulative radiation dose or in-utero exposures. Molecular biology-driven studies demonstrate that chronic low-dose activates several cellular defence mechanisms that help cells to sense, recover, survive, and adapt to radiation stress. These mechanisms include stress-response signaling, DNA repair, immune alterations and most importantly, the radiation-induced adaptive response. The HLNRA data is consistent with the new evolving paradigms of low-dose radiobiology and can help develop the theoretical framework of an alternate dose-response model. A rational integration of radiobiology with epidemiology data is imperative to reduce uncertainties in predicting the potential health risks of chronic low doses of radiation.
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Affiliation(s)
- Anu Ghosh
- Animal House Facility & Radiation Signaling Section, Radiation Biology & Health Sciences Division, Bio-Science Group, Bhabha Atomic Research Centre, Mumbai 400 085, India; Homi Bhabha National Institute (HBNI), Anushaktinagar, Mumbai 400 094, India.
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Priya R, Das B. Global DNA methylation profile at LINE-1 repeats and promoter methylation of genes involved in DNA damage response and repair pathways in human peripheral blood mononuclear cells in response to γ-radiation. Mol Cell Biochem 2021; 477:267-281. [PMID: 34708334 DOI: 10.1007/s11010-021-04265-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 09/17/2021] [Indexed: 02/02/2023]
Abstract
DNA methylation is an epigenetic mechanism, which plays an important role in gene regulation. The present study evaluated DNA methylation profile of LINE1 repeats and promoter methylation of DNA damage response (DDR) and DNA repair (DR) genes (PARP1, ATM, BRCA1, MLH1, XPC, RAD23B, APC, TNFα, DNMT3A, MRE11A, MGMT, CDKN2A, MTHFR) in human peripheral blood mononuclear cells (PBMCs) of healthy donors in response to γ-radiation. Methylation level was correlated with gene expression profile of selected DDR and DR genes (APC, MLH1, PARP1, MRE11A, TNFα, MGMT) to understand their role in gene regulation. Blood samples were collected from 15 random healthy donors, PBMCs were isolated, exposed to 0.1 Gy (low) and 2.0 Gy (high) doses of γ-radiation and proliferated for 48 h and 72 h. Genomic DNA and total RNA were isolated from irradiated PBMCs along with un-irradiated control. Methylation profile was determined from bisulphite converted DNA and amplified by methylation sensitive high resolution melting (MS-HRM) method. Total RNA was converted to cDNA and relative expression was analysed using real time quantitative-PCR. Our results revealed that at 0.1 Gy, MRE11A and TNFα showed significant (P < 0.05) increase in methylation at 72 h. At 2.0 Gy, significant increase (P < 0.05) in methylation profile was observed at LINE1, MRE11A, PARP1, BRCA1, DNMT3A and RAD23B at 48 h and 72 h. PARP1 showed significant positive correlation of methylation status with gene expression. In conclusion, low and high doses of γ-radiation have significant influence on DNA methylation status of LINE1, DDR and DR genes suggesting their potential role as epigenetic signatures in human PBMCs, which can be further explored in human populations.
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Affiliation(s)
- Rashmi Priya
- Low Level Radiation Research Section, Radiation Biology and Health Sciences Division, Bio-Sciences Group, Bhabha Atomic Research Centre, Trombay, Mumbai, 400 085, India
| | - Birajalaxmi Das
- Low Level Radiation Research Section, Radiation Biology and Health Sciences Division, Bio-Sciences Group, Bhabha Atomic Research Centre, Trombay, Mumbai, 400 085, India. .,Homi Bhabha National Institute, Anushaktinagar, Trombay, Mumbai, 400 094, India.
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Beheshti A, McDonald JT, Hada M, Takahashi A, Mason CE, Mognato M. Genomic Changes Driven by Radiation-Induced DNA Damage and Microgravity in Human Cells. Int J Mol Sci 2021; 22:ijms221910507. [PMID: 34638848 PMCID: PMC8508777 DOI: 10.3390/ijms221910507] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 09/24/2021] [Accepted: 09/25/2021] [Indexed: 12/13/2022] Open
Abstract
The space environment consists of a complex mixture of different types of ionizing radiation and altered gravity that represents a threat to humans during space missions. In particular, individual radiation sensitivity is strictly related to the risk of space radiation carcinogenesis. Therefore, in view of future missions to the Moon and Mars, there is an urgent need to estimate as accurately as possible the individual risk from space exposure to improve the safety of space exploration. In this review, we survey the combined effects from the two main physical components of the space environment, ionizing radiation and microgravity, to alter the genetics and epigenetics of human cells, considering both real and simulated space conditions. Data collected from studies on human cells are discussed for their potential use to estimate individual radiation carcinogenesis risk from space exposure.
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Affiliation(s)
- Afshin Beheshti
- KBR, NASA Ames Research Center, Space Biosciences Division, Moffett Field, CA 94035, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Correspondence: or (A.B.); (M.M.)
| | - J. Tyson McDonald
- Department of Radiation Medicine, Georgetown University School of Medicine, Washington, DC 20007, USA;
| | - Megumi Hada
- Radiation Institute for Science & Engineering, Prairie View A&M University, Prairie View, TX 77446, USA;
| | - Akihisa Takahashi
- Gunma University Heavy Ion Medical Center, 3-39-22 Showa-Machi, Maebashi 371-8511, Gunma, Japan;
| | - Christopher E. Mason
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY 10065, USA;
- The World Quant Initiative for Quantitative Prediction, Weill Cornell Medicine, New York, NY 10065, USA
| | - Maddalena Mognato
- Department of Biology, University of Padova, Via U. Bassi 58/B, 35131 Padova, Italy
- Correspondence: or (A.B.); (M.M.)
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Raina A, Sahu PK, Laskar RA, Rajora N, Sao R, Khan S, Ganai RA. Mechanisms of Genome Maintenance in Plants: Playing It Safe With Breaks and Bumps. Front Genet 2021; 12:675686. [PMID: 34239541 PMCID: PMC8258418 DOI: 10.3389/fgene.2021.675686] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 05/04/2021] [Indexed: 01/14/2023] Open
Abstract
Maintenance of genomic integrity is critical for the perpetuation of all forms of life including humans. Living organisms are constantly exposed to stress from internal metabolic processes and external environmental sources causing damage to the DNA, thereby promoting genomic instability. To counter the deleterious effects of genomic instability, organisms have evolved general and specific DNA damage repair (DDR) pathways that act either independently or mutually to repair the DNA damage. The mechanisms by which various DNA repair pathways are activated have been fairly investigated in model organisms including bacteria, fungi, and mammals; however, very little is known regarding how plants sense and repair DNA damage. Plants being sessile are innately exposed to a wide range of DNA-damaging agents both from biotic and abiotic sources such as ultraviolet rays or metabolic by-products. To escape their harmful effects, plants also harbor highly conserved DDR pathways that share several components with the DDR machinery of other organisms. Maintenance of genomic integrity is key for plant survival due to lack of reserve germline as the derivation of the new plant occurs from the meristem. Untowardly, the accumulation of mutations in the meristem will result in a wide range of genetic abnormalities in new plants affecting plant growth development and crop yield. In this review, we will discuss various DNA repair pathways in plants and describe how the deficiency of each repair pathway affects plant growth and development.
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Affiliation(s)
- Aamir Raina
- Mutation Breeding Laboratory, Department of Botany, Aligarh Muslim University, Aligarh, India
- Botany Section, Women’s College, Aligarh Muslim University, Aligarh, India
| | - Parmeshwar K. Sahu
- Department of Genetics and Plant Breeding, Indira Gandhi Agriculture University, Raipur, India
| | | | - Nitika Rajora
- National Agri-Food Biotechnology Institute, Mohali, India
| | - Richa Sao
- Department of Genetics and Plant Breeding, Indira Gandhi Agriculture University, Raipur, India
| | - Samiullah Khan
- Mutation Breeding Laboratory, Department of Botany, Aligarh Muslim University, Aligarh, India
| | - Rais A. Ganai
- Watson-Crick Centre for Molecular Medicine, Islamic University of Science and Technology, Awantipora, India
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Shelke S, Das B. Radio-adaptive response and correlation of non-homologous end joining repair gene polymorphisms [XRRC5 (3R/2R/1R/0R), XRCC6(C/G) and XRCC7 (G/T)] in human peripheral blood mononuclear cells exposed to gamma radiation. Genes Environ 2021; 43:9. [PMID: 33685509 PMCID: PMC7938547 DOI: 10.1186/s41021-021-00176-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Accepted: 02/05/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Radio-adaptive response (RAR) is transient phenomena, where cells conditioned with a small dose (priming) of ionizing radiation shows significantly reduced DNA damage with a subsequent high challenging dose. The role of DNA double strand break repair gene polymorphism in RAR is not known. In the present study attempt was made to find out the influence of NHEJ repair gene polymorphisms [a VNTR; XRCC5 (3R/2R/1R/0R); two single nucleotide polymorphisms (SNPs); XRCC6 (C/G) and XRCC7 (G/T)] with DNA damage, repair and mRNA expression in human PBMCs in dose and adaptive response studies. Genomic DNA extracted from venous blood samples of 20 random healthy donors (16 adaptive and 4 non-adaptive) and genotyping of NHEJ repair genes was carried out using PCR amplified length polymorphism. RESULTS The dose response study revealed significant positive correlation of genotypes at XRRC5 (3R/2R/1R/0R), XRCC6(C/G) and XRCC7 (G/T) with DNA damage. Donors having genotypes with 2R allele at XRCC5 showed significant positive correlation with mRNA expression level (0R/2R: r = 0.846, P = 0.034; 1R/2R: r = 0.698, P = 0.0001 and 2R/2R: r = 0.831, P = 0.0001) for dose response. Genotypes C/C and C/G of XRCC6 showed a significant positive correlation (P = 0.0001), whereas, genotype T/T of XRCC7 showed significant negative correlation (r = - 0.376, P = 0.041) with mRNA expression. CONCLUSION Interestingly, adaptive donors having C/G genotype of XRCC6 showed significantly higher (P < 0.05) mRNA expression level in primed cells suggesting their role in RAR. In addition, NHEJ repair gene polymorphisms play crucial role with radio-sensitivity and RAR in human PBMCs.
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Affiliation(s)
- Shridevi Shelke
- Low Level Radiation Research Section, Radiation Biology & Health Sciences Division, Bio-Sciences Group, Bhabha Atomic Research Centre, Trombay, Mumbai, 400 085, India
| | - Birajalaxmi Das
- Low Level Radiation Research Section, Radiation Biology & Health Sciences Division, Bio-Sciences Group, Bhabha Atomic Research Centre, Trombay, Mumbai, 400 085, India.
- Homi Bhabha National Institute (HBNI), Anushaktinagar, Mumbai, 400094, India.
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Toprani SM, Das B. Radio-adaptive response, individual radio-sensitivity and correlation of base excision repair gene polymorphism (hOGG1, APE1, XRCC1, and LIGASE1) in human peripheral blood mononuclear cells exposed to gamma radiation. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:551-559. [PMID: 32324932 DOI: 10.1002/em.22383] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 04/07/2020] [Accepted: 04/15/2020] [Indexed: 05/27/2023]
Abstract
Radio-adaptive response (RAR) is a biological mechanism, where cells primed with a low dose exhibit reduced DNA damage with a high challenging dose. Single nucleotide polymorphisms (SNPs) of DNA repair genes including base excision repair (BER) pathway are known to be associated with radio-sensitivity but involvement in RAR is not yet understood. In the present study, attempt was made to correlate genotype frequencies of four BER SNPs [hOGG1(Ser326Cys), XRCC1(Arg399Gln), APE1(Asp148Glu) and LIGASE1(A/C)] with DNA damage, repair and mRNA expression level among 20 healthy donors (12 adaptive and 8 nonadaptive). Our results revealed that LIGASE1 (p = .002) showed significant correlation with DNA damage and mRNA expression level with increasing dose. hOGG1 (Ser326Cys), XRCC1 (Arg399Gln) and LIGASE1(A/C) polymorphisms showed significant difference with DNA damage (%T) and mRNA expression profile in primed cells among adaptive donors. In conclusion, BER gene polymorphisms play important role in identifying donors with radio-sensitivity and RAR in human cells.
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Affiliation(s)
- Sneh M Toprani
- Low Level Radiation Research Section, Radiation Biology & Health Sciences Division, Bio-Sciences Group, Bhabha Atomic Research Centre, Trombay, Mumbai, India
| | - Birajalaxmi Das
- Low Level Radiation Research Section, Radiation Biology & Health Sciences Division, Bio-Sciences Group, Bhabha Atomic Research Centre, Trombay, Mumbai, India
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