去氢骆驼蓬碱通过PTEN/Akt/MDM2信号通路抑制胃癌细胞COX-2表达

Harmine inhibits COX-2 expression in gastric cancer cells through PTEN/Akt/MDM2 signaling pathway

目的探讨PTEN基因/Akt/小鼠双微体基因(MDM2)信号通路在去氢骆驼蓬碱(harmine,HM)抑制胃癌细胞COX-2表达中的作用。方法构建PTEN(PTEN-siRNA)、Akt(Akt-siRNA)和MDM2(MDM2-siRNA)小干扰RNA,分别转染胃癌细胞株SGC-7901和MKN-45,Western blot检测HM干预前后PTEN、p-Akt、p-MDM2和COX-2表达。结果 HM诱导PTEN表达,抑制Akt、MDM2磷酸化和COX-2表达。敲减PTEN基因有效地阻断了HM抑制Akt、MDM2磷酸化和COX-2表达的作用,敲减Akt基因可协同HM抑制MDM2磷酸化和COX-2表达,敲减MDM2基因可协同HM抑制COX-2表达。结论 HM可能通过PTEN/Akt/MDM2信号通路,下调胃癌细胞COX-2表达。

Aim To further analyze the effects of PTEN/Akt/MDM2 signaling pathway in the harmine (HM)-mediated inhibition of COX-2 expression in gastric cancer cells. Methods PTEN-siRNA,Akt-siRNA,MDM2-siRNA were constructed and respectively transfected into SGC-7901 and MKN-45 cells,and then added or not added HM for 24 h.The expression of PTEN,Akt and phosphorylated Akt (p-Akt),MDM2 and phosphorylated MDM2 (p-MDM2),as well as COX-2 expression was detected by Western blot. Results HM increased PTEN expression,but inhibited p-Akt,p-MDM2 and COX-2 expression in SGC-7901 and MKN-45 cells.Knockdown of PTEN blocked HM-induced inhibition of Akt and MDM2 phosphorylation,as well as down-regulation of COX-2 expression.Knockdown of Akt and treatment with HM synergistically inhibited p-MDM2 and COX-2 expression.Knockdown of MDM2 and treatment with HM synergistically inhibited COX-2 protein expression. Conclusions HM down-regulates the expression of COX-2 protein in gastric cancer cells via PTEN/Akt /MDM2 signaling pathway.