绞股蓝总皂苷激活Atgl诱导结肠癌细胞凋亡的作用研究

Studies on gypenosides-induced apoptosis of colorectal cancer cells by activating Atgl

目的分析绞股蓝总皂苷(gypenosides,Gyp)对结肠癌HCT116细胞增殖的抑制作用,并阐明其机制。方法采用Cell counting kit-8(CCK-8)法和流式细胞术检测细胞活力、细胞周期分布及凋亡率;采用实时荧光定量聚合酶链式反应(quantitative real time polymerase chain reaction,qRT-PCR)和蛋白质印记(Western blot)分别检测mRNA和蛋白质表达水平;采用Bodipy染色检测脂滴数量。结果Gyp呈浓度依赖性和时间依赖性抑制HCT116细胞增殖;Gyp显著增加G_(0)/G_(1)期HCT116细胞的比例,下调周期蛋白依赖性激酶(cyclin-dependent kinases,CDKs,包括CDK2、CDK4和CDK6)蛋白的表达水平并上调p21和p27蛋白的表达水平;Gyp显著增加凋亡的HCT116细胞的比例,上调活化型半胱氨酸蛋白酶-3(Cleaved caspase-3)、活化型聚(ADP-核糖基)转移酶1[Cleaved Poly(ADP-ribose)polymerase 1,Cleaved PARP1]和Bcl-2相关X蛋白(Bcl-2 associated X protein,Bax)的表达水平并下调B淋巴细胞瘤-xl(B cell lymphoma-xl,Bcl-xl)蛋白的表达水平;Gyp显著降低HCT116细胞中脂滴的数量,下调脂肪酸合酶(fatty acid synthase,Fasn)mRNA的表达水平并上调甘油三酯脂酶(adipose triglyceride lipase,Atgl)mRNA及蛋白的表达水平;与Gyp单独处理相比,Gyp与阿格列他汀(Atgl inhibitor,Atgl抑制剂,简称Atgli)合用显著增加HCT116细胞中的脂滴数量、显著下调HCT116细胞的凋亡率,并降低Cleaved caspase-3的表达水平。结论Gyp通过诱导细胞周期阻滞和凋亡抑制HCT116细胞增殖,其机制与Atgl介导的脂代谢有关。

Objective To investigate the inhibitory effect of gypenosides(Gyp)on colorectal cancer HCT116 cells and elucidate its underlying mechanisms.Methods Cell counting kit-8(CCK-8)assay and flow cytometry were used to detect Gyp′s effects on cell viability,cell cycle distribution,and apoptosis rate.The expression levels of mRNA and protein were detected by quantitative real time polymerase chain reaction(qRT-PCR)and western blot,respectively.The number of lipid droplets was detected by Bodipy staining.Results Gyp demonstrated the dose-and time-dependent inhibition of HCT116 cell proliferation.Gyp significantly induced G_(0)/G_(1)phase cell cycle arrest,down-regulated cyclin-dependent kinases(CDKs,including CDK2,CDK4,and CDK6)proteins,and up-regulated p21 and p27 proteins.Gyp significantly increased cell apoptosis rate,and elevated Cleaved caspase-3,Cleaved Poly(ADP-ribose)polymerase 1(Cleaved PARP1),and Bcl-2 associated X protein(Bax)protein expressions,and decreased B cell lymphoma-xl(Bcl-xl)protein levels.Gyp also decreased lipid droplet formation,down-regulated fatty acid synthase(Fasn)mRNA,and up-regulated adipose triglyceride lipase(Atgl)mRNA and protein levels.Compared with Gyp alone treatment,the combination of Gyp and Atglisatin(Atgli,an adipose triglyceride lipase inhibitor)significantly increased the number of lipid droplets,with a concurrent reduction in apoptosis and Cleaved caspase-3 expression.Conclusion Gyp inhibits HCT116 cell proliferation by inducing cell cycle arrest and apoptosis.The mechanism involves the modulation of lipid metabolism mediated by Atgl.