雌激素通过调节Nrf2/ROS信号通路诱导正常乳腺细胞生物学改变

Estrogen⁃induced biological changes of normal breast cells by regulating Nrf2/ROS signaling pathway

目的探讨雌激素通过Nrf2/ROS信号通路对正常乳腺上皮细胞生物学改变的诱导作用。方法选取正常乳腺上皮细胞株MCF-10A和MCF-12A,实验设立空白组和雌激素组(5 nmol/L)。分别采用MTT法、LDH实验、酶联免疫吸附测定法(ELISA)、DCFH-DA荧光探针标记法和氧化酶活性测定、划痕实验、平板克隆实验、AnnexinV/PI双染色法检测干预后乳腺细胞的生物学表现;Western blot和PCR检测乳腺细胞中Nrf2、HO-1、NQO1蛋白及mRNA表达水平。结果雌激素可诱导细胞活力、迁移和克隆能力的增强,同时降低细胞凋亡水平。雌激素可以诱导ROS的积累,抑制细胞中SOD、GPX、CAT和TAC等氧化酶的活性,进而促进细胞中LDH和8-OHdG的水平升高,导致细胞毒性和DNA氧化损伤增加。此外,Western blot和RT-qPCR结果表明,雌激素诱导后可抑制Nrf2、HO-1和NQO1的表达。结论雌激素可以诱导正常乳腺细胞的增殖和降低细胞凋亡,并通过调节Nrf2/ROS信号通路来增加DNA的氧化损伤,进而诱导乳腺细胞的生物学改变。

Objective To investigate the biological changes of normal breast epithelial cells induced by estrogen through Nrf2/ROS signaling pathway.Methods Normal breast epithelial cell lines MCF⁃10A and MCF⁃12A were selected and the control group and estrogen group(5 nmol/L)were established.MTT assay,LDH assay,enzyme⁃linked immunosorbent assay(ELISA),DCFH⁃DA fluorescence probe labeling assay,oxidase assay,wound⁃heal⁃ing assay,colony⁃forming assay and annexinV/PI double staining were used to detect the biological characteristics of breast cells after intervention.Expression of Nrf2,HO⁃1,NQO1 protein and mRNA in breast cells were detect⁃ed by Western blot and PCR.Results Estrogen induced the enhancement of cell viability,migration and cloning ability,and reduced cell apoptosis.Estrogen induced the accumulation of ROS and inhibited the activities of SOD,GPX,CAT and TAC in the cells,and then increased the level of LDH and 8⁃OHdG in the cells,leading to the increase of cytotoxicity and oxidative damage of DNA.In addition,Western blot and RT⁃qPCR showed that estrogen induced inhibition of Nrf2,HO⁃1 and NQO1 expression.Conclusion Estrogen can induce the proliferation and apoptosis of normal breast cells,and regulate Nrf2/ROS signal pathway to increase the oxidative damage of DNA,and then induce the biological changes of breast cells.