磷脂酰乙醇胺N-甲基转移酶2过表达抑制磷脂酶Cγ1磷酸化及转位

Overexpression of PEMT2 inhibits the phosphorylation and translocation of PLCγ1

目的探讨转染磷脂酰乙醇胺N-甲基转移酶2(PEMT2)基因抑制大鼠肝癌CBRH-7919细胞增殖的机制。方法采用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳和Western blot方法,观察转染PEMT2基因对大鼠肝癌CBRH 7919细胞磷脂酶C γ 1(PLC γ 1)磷酸化及在细胞内转位的影响;同时观察转染PEMT2基因对肝细胞生长因子受体(c- Met)自身磷酸化活化的影响。结果转染PEMT2后,质膜结合的PLC γ下降,为对照组的45％。膜结合的磷酸化PLC γ 1约为对照组细胞的27％,同时c-Met磷酸化程度显著下降,约为对照组细胞的32％。结论转染PEMT2基因可抑制细胞PLC γ 1磷酸化及由胞浆向质膜转位,抑制c-Met自身磷酸化活化,从而下调CBRH-7919细胞c-Met／PLC γ 1信号转导途经。

Objective To explore the mechanism of CBRH-7919 cell proliferation inhibition by transfecting phosphatidylethanolamine N-methyltransferase 2 gene （PEMT2）. Methods The effects of PEMT2 transfection on phosphorylation and translocation from cytosol to plasma membrane of PLCγ1 in cells were studied using SDS-PAGE and Western blot techniques. The phosphorylation and activity of c-Met were determined. Results After transfection of pemt2, the PLCγ1 and phosphorylated PLCγ1 conjugated with plasma membrane were decreased by 45% and 27% of that of control cells respectively, and the phosphorylated c-Met was decreased to 32% of that of control cells. Conclusions Transfection of phosphatidylethanolamine Nmethyltransferase 2 gene can inhibit the phosphorylation and translocation from cytosol to plasma membrane of PLCγ1 in cells. At the same time, the autophosphorylation of c-Met was decreased, which suggests that transfection of phosphatidylethanolamine N-methyltransferase 2 gene can downregulate the c-Met/PLCγ1 signaling pathway in CBRH-7919 cells.