还原型谷胱甘肽靶向氧化应激对肝癌干细胞的作用

Reduced glutathione supplement targets oxidative stress and restricts the stemness of hepatocellular carcinoma

目的探讨还原型谷胱甘肽(glutathione,GSH)对肝细胞癌(hepatocellular carcinoma,HCC)干细胞性的作用。方法采用总谷胱甘肽/氧化型谷胱甘肽(T-GSH/GSSG)测试盒检测细胞内T-GSH/GSSG水平;应用CCK-8实验评估细胞活力及干细胞培养基培养干细胞球(HCC sphere);运用流式细胞技术分析CD133阳性细胞亚群比例。结果HCC细胞中内源性T-GSH/GSSG水平比正常细胞显著升高。外源性补充GSH减少胞内活性氧物质(reactive oxygen species,ROS)并抑制HCC细胞活力及HCC sphere形成。进一步分析发现GSH显著降低CD133+肝癌干细胞(liver cancer stem cells,LCSC)的亚群比例。结论HCC细胞中ROS水平及抗氧化防御能力增强。外源性GSH能够降低胞内的ROS水平,并抑制HCC细胞活力及干细胞性,降低LCSC在HCC细胞中的亚群比例。为靶向异常氧化应激(oxidative stress,OS)及肿瘤干细胞(cancer stem cell,CSC)治疗HCC提供了新靶点。

Purpose To investigate the effect of reduced glutathione(GSH)upon the stemness of hepatocellular carcinoma(HCC).Methods The contents of endogenous total-GSH(T-GSH)and/or oxidized GSH(GSSG)were evaluated using intracellular T-GSH/GSSG detection kit.Cell viability was evaluated using CCK-8 and HCC sphere was cultured in growing sphere medium.The subpopulation of CD133-positive liver cancer stem cells(LCSC)was analyzed using flow cytometry(FCM).Results Intracellular T-GSH/GSSG assessment showed that the content of endogenous T-GSH/GSSG was significantly increased in HCC cells.Exogenous GSH supplement ameliorated reactive oxygen species(ROS)accumulation and inhibited HCC cell viability and the formation of HCC sphere.FCM analysis showed that GSH alleviated the subpopulation of CD133-positive LCSC in HCC cells.Conclusion HCC cells exhibit an enhanced antioxidant defense with an increasing T-GSH/GSSG level.GSH supplement attenuates ROS level and cell viability,as well inhibits LCSC growth and alleviates LCSC subpopulation in HCC cells.This findings suggest that GSH supplement may provide a promising therapeutic strategy against HCC through targeting aberrant oxidative stress and cancer stem cells.