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Alsbeih G, Al-Harbi N, Ismail S, Story M. Impaired DNA Repair Fidelity in a Breast Cancer Patient With Adverse Reactions to Radiotherapy. Front Public Health 2021; 9:647563. [PMID: 34164366 PMCID: PMC8216558 DOI: 10.3389/fpubh.2021.647563] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 04/20/2021] [Indexed: 11/24/2022] Open
Abstract
We tested the hypothesis that differences in DNA double-strand break (DSB) repair fidelity underlies differences in individual radiosensitivity and, consequently, normal tissue reactions to radiotherapy. Fibroblast cultures derived from a radio-sensitive (RS) breast cancer patient with grade 3 adverse reactions to radiotherapy were compared with normal control (NC) and hyper-radiosensitive ataxia-telangiectasia mutated (ATM) cells. DSB repair and repair fidelity were studied by Southern blotting and hybridization to Alu repetitive sequence and to a specific 3.2-Mbp NotI restriction fragment on chromosome 21, respectively. Results for DNA repair kinetics using the NotI fidelity assay showed significant differences (P < 0.001) with higher levels of misrepaired (misrejoined and unrejoined) DSBs in RS and ATM compared with NC. At 24-h postradiation, the relative fractions of misrepaired DSBs were 10.64, 23.08, and 44.70% for NC, RS, and ATM, respectively. The Alu assay showed significant (P < 0.05) differences in unrepaired DSBs only between the ATM and both NC and RS at the time points of 12 and 24 h. At 24 h, the relative percentages of DSBs unrepaired were 1.33, 3.43, and 12.13% for NC, RS, and ATM, respectively. The comparison between the two assays indicated an average of 5-fold higher fractions of misrepaired (NotI assay) than unrepaired (Alu assay) DSBs. In conclusion, this patient with increased radiotoxicity displayed more prominent misrepaired than unrepaired DSBs, suggesting that DNA repair fidelity is a potential marker for the adverse reactions to radiotherapy. More studies are required to confirm these results and further develop DSB repair fidelity as a hallmark biomarker for interindividual differences in radiosensitivity.
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Affiliation(s)
- Ghazi Alsbeih
- Radiation Biology Section, Biomedical Physics Department, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.,Experimental Radiation Oncology Department, University of Texas M.D. Anderson Cancer Center, Houston, TX, United States.,College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Najla Al-Harbi
- Radiation Biology Section, Biomedical Physics Department, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Sheikh Ismail
- Experimental Radiation Oncology Department, University of Texas M.D. Anderson Cancer Center, Houston, TX, United States.,Commercialization & Entrepreneurship Department, Texas A&M University, Bellaire, TX, United States
| | - Michael Story
- Experimental Radiation Oncology Department, University of Texas M.D. Anderson Cancer Center, Houston, TX, United States.,Radiation Oncology Department, University of Texas Southwestern Medical Centre, Dallas, TX, United States
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Chen FM, Zhang YX, Li XF, Gao JF, Ma H, Wang XL, Li Y, Li C, Zhang YN, Zhang YT, Kan HX, Li H, Zhang SG, Hao FR, Wang MC. The Prognostic Value of Deficient Mismatch Repair in Stage II-IVa Nasopharyngeal Carcinoma in the Era of IMRT. Sci Rep 2020; 10:9690. [PMID: 32546739 PMCID: PMC7298002 DOI: 10.1038/s41598-020-66678-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 05/26/2020] [Indexed: 01/08/2023] Open
Abstract
In the era of intensity-modulated radiotherapy (IMRT), it is important to analyse the prognostic value of deficient mismatch repair (dMMR) in nasopharyngeal carcinoma (NPC). In this study, in pretreatment biopsies of 69 patients with stage II-IVa NPC, the expression levels of MMR proteins, including MLH1, MSH2, MSH6 and PMS2, were assessed by immunohistochemistry (IHC). The median follow-up time was 37.5 months (3.1-87.4 months). 50.7% of cases (35/69) showed preserved expression of all 4 MMR proteins, which was interpreted as proficient mismatch repair (pMMR). Only 1.5% of cases (1/69) lost expression of all 4 MMR proteins, 26.1% of cases (18/69) have PMS2 loss alone and 21.7% of cases (15/69) lost expression of both PMS2 and MLH1. Thus, 49.3% of cases (34/69) lost expression of one or more MMR proteins, which was interpreted as dMMR. There was no significant difference (P > 0.05) in terms of sex, age, clinical stage, T category, N category or therapy regimens between the dMMR and pMMR groups. The multivariate Cox regression analysis revealed that dMMR was an independent significant prognostic factor for distant metastasis-free survival (DMFS) (dMMR vs pMMR: P = 0.01, HR = 0.25, 95% CI: 0.09~0.75). Therefore, NPC patients with dMMR had significantly superior DMFS compared with patients with pMMR. It can be expected that dMMR will become a new independent prognostic factor for NPC.
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Affiliation(s)
- Fang-Ming Chen
- Department of Radiation Oncology, Rongcheng People's Hospital, Weihai, China
| | - Yun-Xiang Zhang
- Department of Pathology, Weifang People's Hospital, Weifang, China
| | - Xiu-Feng Li
- Department of Pathology, Weifang People's Hospital, Weifang, China
| | - Jian-Fang Gao
- Department of Pathology, Weifang People's Hospital, Weifang, China
| | - Hao Ma
- Department of Pathology, Weifang People's Hospital, Weifang, China
| | - Xiao-Li Wang
- Department of Radiation Oncology, Weifang People's Hospital, Weifang, China
| | - Yang Li
- Department of Radiation Oncology, Weifang People's Hospital, Weifang, China
| | - Cheng Li
- Clinical School, Weifang Medical University, Weifang, China
| | - Ya-Nan Zhang
- Clinical School, Weifang Medical University, Weifang, China
| | - Ya-Ting Zhang
- Clinical School, Weifang Medical University, Weifang, China
| | - Hong-Xing Kan
- Department of Radiation Oncology, Yantai Yuhuangding Hospital, Yantai, China
| | - Han Li
- Department of Oncology, The Fourth People's Hospital of Zibo City, Zibo, China
| | - Shi-Geng Zhang
- Department of Radiation Oncology, Taian Tumour Prevention and Treatment Hospital, Taian, China
| | - Fu-Rong Hao
- Department of Radiation Oncology, Weifang People's Hospital, Weifang, China.
- Weifang Key Laboratory of Radiophysics and Oncological Radiobiology, Weifang, China.
| | - Ming-Chen Wang
- Department of Radiation Oncology, Weifang People's Hospital, Weifang, China.
- Weifang Key Laboratory of Radiophysics and Oncological Radiobiology, Weifang, China.
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