Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida.
Department of Nutritional Sciences & Toxicology, Comparative Biochemistry Program, University of California, Berkeley, California.
Toxicol Sci. 2019 May 1;169(1):235-245. doi: 10.1093/toxsci/kfz037.
Acetaldehyde, a metabolite of ethanol, is a cellular toxicant and a human carcinogen. A genome-wide CRISPR-based loss-of-function screen in erythroleukemic K562 cells revealed candidate genetic contributors affecting acetaldehyde cytotoxicity. Secondary screening exposing cells to a lower acetaldehyde dose simultaneously validated multiple candidate genes whose loss results in increased sensitivity to acetaldehyde. Disruption of genes encoding components of various DNA repair pathways increased cellular sensitivity to acetaldehyde. Unexpectedly, the tumor suppressor gene OVCA2, whose function is unknown, was identified in our screen as a determinant of acetaldehyde tolerance. Disruption of the OVCA2 gene resulted in increased acetaldehyde sensitivity and higher accumulation of the acetaldehyde-derived DNA adduct N2-ethylidene-dG. Together these results are consistent with a role for OVCA2 in adduct removal and/or DNA repair.
乙醛是乙醇的代谢产物，是一种细胞毒性物质和人类致癌物。在红白血病 K562 细胞中进行的基于全基因组 CRISPR 的功能丧失筛选揭示了候选遗传因素，这些因素影响乙醛的细胞毒性。对细胞暴露于较低剂量乙醛的二次筛选同时验证了多个候选基因，这些基因的缺失导致对乙醛的敏感性增加。破坏各种 DNA 修复途径的基因编码组件增加了细胞对乙醛的敏感性。出乎意料的是，在我们的筛选中，肿瘤抑制基因 OVCA2 被确定为乙醛耐受的决定因素，其功能未知。OVCA2 基因的破坏导致乙醛敏感性增加和乙醛衍生的 DNA 加合物 N2-乙基-dG 的积累增加。这些结果表明 OVCA2 在加合物去除和/或 DNA 修复中起作用。
