MAPK通路抑制剂对不同PTEN状态子宫内膜癌细胞作用及机制

摘要

Objective To explore whether sensitivity to p38 MAPK inhibitors are specifically due to status of PTEN in endometrial cancer Ishikawa and HEC-1A cells, and its related mechanisms. Methods Vector mediated PTEN-siRNA and PTEN gene were transfected into two endometrial cancer cells. The expression of PTEN protein was de-tected by confocal spectral microscopy. SB203580 treated for 48 hours, cell proliferation, cell early apoptosis, were studied by MTT method and flow cytometry (FCM), respectively. The activation of p38MAPK and 4E-BP1 was ex-amined by Western blot. Results The PTEN protein expression in two endometrial carcinoma cells ( Ishikawa, HEC-1A) was exchanged by vector mediated PTEN siRNA and PTEN plasmid stable transfection. SB203580 could inhibit cell viability , induce cell early apoptosis of PTEN loss Ishikawa and HEC-1 A cells after the cells exposed to SB203580 . The expression of phosphorylation of p38 MAPK and 4 E-BP1 protein in PTEN loss Ishikawa and HEC-1A cells was significantly decreased. Compared with PTEN intact Ishikawa and HEC-1A cells the difference was significant (P<0.01). Conclusion Loss of PTEN results in the activation of p38MAPK signal pathway, and due to sensitive to p38MAPK signal transduction inhibitors in endometrial carcinoma cells. Those results suggest that cells with loss of PTEN have a feedback downregulation of receptor p38MAPK signalling pathway, which leads to PTEN in-activation of p38MAPK signaling pathway, the transcription change of the downstream gene targeted p38MAPK.%目的探讨PTEN缺失和表达下p38MAPK通路抑制剂(SB203580)对子宫内膜癌细胞Ishikawa及HEC-1A的作用及其机制。方法PTEN小分子干扰RNA及PTEN基因转染后,激光共聚焦显微镜检测PTEN蛋白表达；SB203580干预48 h,流式细胞术、MTT法及Western blot法分别检测细胞干预后子宫内膜癌细胞早期凋亡、细胞增殖活性、p38MAPK通路的磷酸化水平及其下游底物4E-BP1蛋白的磷酸化情况。结果PTEN小分子干扰 RNA封闭与 PTEN稳定转染使两株子宫内膜癌细胞( Ishikawa, HEC-1A) PTEN表达水平改变。 SB203580干预使 PTEN 缺失 Ishikawa 及HEC-1A细胞生长显著抑制,细胞发生早期凋亡；p38MAPK通路磷酸化水平和磷酸化4E-BP1蛋白表达均显著下降；与PTEN表达两种细胞比较,差异均有统计学意义( P<0.01)。结论内外源性 PTEN 缺失使两株子宫内膜癌细胞中p38MAPK通路活化,对SB203580敏感性增加,其机制可能与PTEN缺失导致PTEN对p38MAPK信号通路负性调控功能丧失,引发p38MAPK信号通路下游底物4E-BP1激活导致p38MAPK通路活化有关。