Zhang Qiaojian, Feng Huimin, Hu Guiping, Zheng Pai, Su Zekang, Zhang Yali, Hong Shiyi, Xu Jiayu, Wang Tiancheng, Jia Guang
Department of Occupational and Environmental Health Science, School of Public Health, Peking University, Beijing, China.
Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.
Environ Int. 2023 Apr;174:107895. doi: 10.1016/j.envint.2023.107895. Epub 2023 Mar 21.
Hexavalent chromium [Cr(VI)] is rarely found in nature. Its occurrence in the environment is mainly due to anthropogenic sources. Our previous studies have shown that Cr(VI) exposure could change the expression profile of long noncoding RNAs (lncRNAs). However, the relationship between lncRNAs and genetic damage induced by Cr(VI) remains unclear. In this study, RT-qPCR was used to verify the expression of genes and lncRNAs involved in DNA damage repair in BEAS-2B cells exposed to different Cr(VI) concentrations. After screening out LNC-DHFR-4:1, overexpression and knockdown models of BEAS-2B cells were used to further identify the relationship between the lncRNA and RAD51. RT-qPCR and indirect immunofluorescence were used to detect expression. Our results revealed that with increasing Cr(VI) concentration, γH2AX expression was increased, while the expression of RAD51 was decreased. Meanwhile, LNC-DHFR-4:1 acted as a competitive endogenous RNA to regulate the expression of γH2AX and RAD51, which further affected DNA damage repair. The overexpression of LNC-DHFR-4:1 induced a twofold decrease in γH2AX and a onefold increase in RAD51, and its knockdown showed the opposite results. These results suggested that LNC-DHFR-4:1 might be a potential biomarker of Cr(VI)-induced DNA damage repair in BEAS-2B cells.
六价铬[Cr(VI)]在自然界中很少见。其在环境中的出现主要归因于人为来源。我们之前的研究表明，Cr(VI)暴露可改变长链非编码RNA（lncRNA）的表达谱。然而，lncRNA与Cr(VI)诱导的遗传损伤之间的关系仍不清楚。在本研究中，采用RT-qPCR验证暴露于不同浓度Cr(VI)的BEAS-2B细胞中参与DNA损伤修复的基因和lncRNA的表达。筛选出LNC-DHFR-4:1后，利用BEAS-2B细胞的过表达和敲低模型进一步确定lncRNA与RAD51之间的关系。采用RT-qPCR和间接免疫荧光检测表达情况。我们的结果显示，随着Cr(VI)浓度的增加，γH2AX表达增加，而RAD51表达降低。同时，LNC-DHFR-4:1作为竞争性内源性RNA调节γH2AX和RAD51的表达，进而影响DNA损伤修复。LNC-DHFR-4:1的过表达导致γH2AX降低两倍，RAD51增加一倍，其敲低则显示相反的结果。这些结果表明，LNC-DHFR-4:1可能是BEAS-2B细胞中Cr(VI)诱导的DNA损伤修复的潜在生物标志物。
