Tissue-specific DNA damage response in Mouse Whole-body irradiation

• Published in: Molecular & cellular toxicology Vol. 18; no. 1; pp. 131 - 139
• Main Authors: Lee, Seon-Gyeong, Kim, Namwoo, Park, In Bae, Park, Jun Hong, Myung, Kyungjae
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 01.01.2022; 대한독성 유전단백체 학회
• Subjects: Biomedical and Life Sciences; Cell Biology; Life Sciences; Original Article; Pharmacology/Toxicology; 생물학; Whole-body irradiation; RAD51; PCNA; DNA damage response; γH2AX
• ISSN: 1738-642X; 2092-8467
• DOI: 10.1007/s13273-021-00195-w

Background Genomic instability is a hallmark of various cancers, and DNA repair is an essential process for maintaining genomic integrity. Mammalian cells have developed various DNA repair mechanisms in response to DNA damage. Compared to the cellular response to DNA damage, the in vivo DNA damage response (DDR) of specific tissues has not been studied extensively. Objective In this study, mice were exposed to whole-body gamma (γ)-irradiation to evaluate the specific DDR of various tissues. We treated male C57BL6/J mice with γ-irradiation at different doses, and the DDR protein levels in different tissues were analyzed. Results The level of gamma-H2A histone family member X (γH2AX) increased in most organs after exposure to γ-irradiation. In particular, the liver, lung, and kidney tissues showed higher γH2AX induction upon DNA damage, compared to that in the brain, muscle, and testis tissues. RAD51 was highly expressed in the testis, irrespective of irradiation. The levels of proliferating cell nuclear antigen (PCNA) and ubiquitinated PCNA increased in lung tissues upon irradiation, suggesting that the post-replication repair may mainly operate in the lungs in response to γ-irradiation. Conclusion These results suggest that each tissue has a preferable repair mechanism in response to γ-irradiation. Therefore, the understanding and application of tissue-specific DNA damage responses could improve the clinical approach of radiotherapy for treating specific cancers.