DNA repair pathway choice at various conditions immediately post irradiation

• Authors: Min Liu, Jilin University; Hongyan Wang, affiliation; Solah Lee, Emory University; Bailong Liu, Jilin University; Lihua Dong, Jilin University; Ya Wang, Emory University
• Journal Title: International Journal of Radiation Biology
• Volume: Volume 92, Number 12
• Publisher: Taylor & Francis | 2016-01-01, Pages 819-822
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1080/09553002.2016.1230243
• Subjects: Health Sciences, Radiology; Biology, Genetics
• Keywords: Science & Technology; Life Sciences & Biomedicine; Technology; Biology; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging; Life Sciences & Biomedicine - Other Topics; DNA double strand break (DSB); DNA repair; homologous recombination repair (HRR); ionizing radiation; non-homologous end-joining (NHEJ); sublethal damage repair (SLDR); potentially lethal damage repair (PLDR); heavy ion; POTENTIALLY LETHAL DAMAGE; DEPENDENT PROTEIN-KINASE; STRAND BREAK REPAIR; HUMAN-TUMOR CELLS; HOMOLOGOUS RECOMBINATION; MAMMALIAN-CELLS; SUBLETHAL DAMAGE; RADIATION; CONTRIBUTES; SENSITIVITY

Abstract

Purpose: To clarify which DNA double-strand break repair pathway, non-homologous end-joining (NHEJ), homologous recombination repair (HRR) or both, plays a key role in potentially lethal damage repair (PLDR). Methods and materials: Combining published data and our new potentially lethal damage repair (PLDR) data, we explain whether similar to sublethal damage repair (SLDR), PLDR also mainly depends on NHEJ versus HRR. The PLDR data used the same cell lines: wild type, HRR or NHEJ-deficient fibroblast cells, as those SLDR data published by our laboratory previously. The PLDR condition that we used was as commonly described by many other groups: the cells were collected immediately or overnight post ionizing radiation for colony formation after cultured to a plateau phase with a low concentration of serum medium. Results: Enough data from other groups and our lab showed that wild type or HRR-deficient cells had efficient PLDR, but NHEJ deficient cells did not. Conclusion: NHEJ contributes more to PLDR than HRR in mammalian cells, which is similar to SLDR. Since both SLDR and PLDR are relevant to clinical tumor status while undergoing radiotherapy, such clarification may benefit radiotherapy in the near future.