THAP11通过抑制p53的泛素化影响食管癌细胞的增殖和凋亡

THAP11 mediates the proliferation and apoptosis of esophageal cancer cells via inhibiting ubiquitination of p53

目的:探讨死亡相关蛋白(thanatos-associated protein,THAP)11对食管癌细胞增殖和凋亡的影响及其潜在的机制。方法:采用蛋白质印迹法检测人食管上皮细胞Het-1A和人食管癌细胞(Eca109,TE-1和Ec 9706)中THAP11的表达。将食管癌TE-1细胞分为空白对照(NC)组、阴性对照(LV-LC)组、TRAP11(LV-TRAP11)组,按分组处理细胞后,采用MTT法检测细胞活力,流式细胞术检测细胞凋亡,caspases试剂盒检测caspase-3和caspase-9的活性。采用体外泛素化实验检测TE-1细胞的p53泛素化水平。结果:与Het-1A细胞相比,食管癌细胞中THAP11的表达显著下降(P<0.05)。LV-THAP11转染食管癌细胞后,细胞活力降低(P<0.05),凋亡率升高(P<0.05),caspase-3和caspase-9活性升高(P<0.05)。THAP11能够提高食管癌细胞中p53蛋白的表达(P<0.05)。与LV-LC组相比,转染THAP11后食管癌细胞中p53的表达上调(P<0.05),MDM2调节的p53的泛素化也被抑制。结论:THAP11通过抑制p53的泛素化抑制食管癌细胞的增殖,促进食管癌细胞的凋亡。

Objective:To investigate the effects of thanatos-associated protein 11 (THAP11) on the proliferation and apoptosis of esophageal cancer cell and the underlying mechanism.Methods:Expression of THAP11 in human esophageal epithelial cells (Het-1A) and esophageal cancer cells (Eca109,TE-1,Ec 9706) were detected by Western blotting.Esophageal cancer TE-1 cells were divided into 3 groups:a normal control (NC) group,a negative control (LV-NC) group and a THAP11 (LV-THAP11) group.Then the cell proliferation were detected by MTT assay,cell apoptosis were detected by flow cytometry,caspase-3 and caspase-9 levels were detected by caspases kits.Ubiquitination of p53 was determined in esophageal cancer TE-1 cells.Results:Expression of THAP11 was reduced in esophageal cancer cells compared with human esophageal epithelial cells (P<0.05).After transfection with LV-THAP11 in TE-1 cells,cell viability was reduced (P<0.05),while apoptosis rate and caspase-3 and caspase-9 levels were increased (P<0.05),indicating that THAP11 inhibited growth of esophageal cancer cells.In addition,the THAP11 increased the levels of p53 (P<0.05) and inhibited the ubiquitination of p53 regulated by MDM2.Conclusion:THAP11 may inhibit the proliferation of esophageal cancer cells by inhibiting ubiquitination of p53.