The Expression of Mammalian Target of Rapamycin in Ishikawa and HEC-1A Cells

The activation of mammalian target of rapamycin （mTOR） signaling pathway in endometrial carcinoma cells Ishikawa and HEC-1A was investigated. The expression of mTOR was detected by confocal fluorescence microscopy in Ishikawa and HEC-1A cells. The mRNA levels of PTEN and mTOR, the downstream substrate S6K1 and 4E-BP1 protein were assayed by RT-PCR and Western blot, respectively. The expression of PTEN in Ishikawa cells was deficient, but intact in HEC-1A cells respectively （P〈0.01）. There was mTOR expression in both Ishikawa and HEC-1A cells and the phosporylated substrate levels in Ishikawa cells were higher than those in HEC-1A cells （P〈0.05）. mTOR signaling pathway is activated in two endometrial carcinoma cell strains and the status of activation is related with PTEN expression of the cells. The activation level of mTOR is higher in PTEN-deficient endometrial carcinoma cells than that in PTEN-intact endometrial carcinoma cells.

两株子宫内膜癌细胞中mTOR信号通路激活的研究

目的探讨PTEN缺失Ishikawa和PTEN完整HEC-1A细胞中mTOR信号通路的激活。方法激光共聚焦显微镜检测Ishikawa和HEC-1A细胞中PTEN蛋白表达;RT-PCR和western blot法从mRNA和蛋白水平分别检测mTOR mRNA和下游磷酸话靶蛋白S6K1和4E-BP1表达。结果Ishikawa细胞中PTEN蛋白表达缺失,HEC-1A细胞PTEN蛋白表达显著(P<0.01);两株细胞中均存在mTOR mRNA表达,而Ishikawa细胞中表达水平要高于HEC-1A细胞(P<0.05);Ishikawa细胞中S6K1和4E-BP1蛋白的磷酸化要明显高于HEC-1A细胞(P<0.05)。结论两株子宫内膜癌细胞中均存在mTOR信号通路的激活,这种激活水平与PTEN相关,PTEN缺失Ishikawa细胞的激活水平较高。