PI3K/Akt/mTOR和MAPK/ERK信号通路在胃癌细胞生长中协同作用及机制

Synergistic effects and mechanism of PI3K/Akt/mTOR and MAPK/ERK signaling pathway on growth of gastric cancer cells

目的初步探讨PI3K/Akt/m TOR和MAPK/ERK信号通路在胃癌细胞生长中的协同作用。方法采用不同浓度的PI3K/Akt/m TOR和MAPK/ERK信号通路抑制剂rapamycin与PD98059分别单独及联合作用于胃癌细胞SGC-7901。采用CCK8法检测SGC-7901细胞增殖情况;实时荧光定量PCR检测关键基因m RNA的表达;蛋白印迹法(WB)检测相关蛋白的表达;流式细胞术检测细胞周期和凋亡的变化。结果 Rapamycin(12.5、25、50、100、150、200 nmol/L)与PD98059(25、50、100、200、300、400μmol/L)单独作用可抑制SGC-7901细胞增殖活性,联合作用也可抑制其活性,且联合组的抑制作用强于单独作用(P<0.05)。与rapamycin、PD98059单独作用相比,联合组对AKT、m TOR、MEK、ERK基因m RNA表达和p-AKT、p-m TOR、p-MEK1/2、p-ERK1/2蛋白表达的抑制作用明显增强(P<0.05)。联合组阻滞于G0/G1期的细胞比例显著增多,且具有更强的促凋亡作用。结论 PI3K/Akt/m TOR和MAPK/ERK信号通路在胃癌细胞生长中具有一定的协同调控作用。

Objective To investigate the synergistic effect of phosphalyl inositol 3-kinase protein kinase B/mammalian target of rapamycin（PI3 K/Akt/m TOR） and mitogen activated protein kinase/extracellular signal-regulated kinase（MAPK/ERK） signaling pathways on gastric cancer cell growth. Methods Different concentrations of PI3 K/Akt/m TOR and MAPK/ERK signaling pathways inhibitor rapamycin and PD98059 were used alone and in combination to SGC-7901 cells,respectively. The proliferation of SGC-7901 cells was detected with cholecystokinin-8（CCK8）. The m RNA expressions of key genes were detected with real time quantitative polymerase chain reaction（RT-q PCR）. The expressions of related proteins were detected with Western blot. Cell cycles and apoptosis were detected with flow cytometry. Results Both the single administration of rapamycin（at dosages of 12.5, 25, 50, 100, 150, and 200 nmol/L） and PD98059（at dosages of 25,50, 100, 150, 200, 300, and 400 μmol/L） could inhibit the growth of SGC-7901 cells; so did the combined administration of the two agents and the inhibitory effect of the combined administration was stronger than that of the single agent（P〈0.05）.The combined administration of rapamycin and PD98059 exerted a much stronger inhibitive effect on the m RNA expressions of AKT, m TOR, mitogen activated protein kinase kinase（MEK）, ERK and the protein expressions of p-AKT, p-m TOR,p-MEK1/2 and p-ERK1/2 than the single administration of one of the two agents（P〈0.05 for all）; higher proportions of cells arrested at G0/G1 phase and apoptosis cells were also observed for the SGC-7901 cells with combined administration than those for the SGC-7901 cells with the single administration. Conclusion PI3 K/Akt/m TOR and MAPK/ERK signaling pathways have a synergistic effect on the growth of gastric cancer cells.