EGF及其受体在二甲双胍抑制人肺腺癌细胞增殖中的作用

摘要

Objective To observe the effect of metformin on the expression of epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) in human lung adenocarcinoma A549 cells.Methods In vitro,A549 cells were treated with different concentrations of metformin.The proliferation of cells was detected by MTT assay,and the apoptosis of cells was detected by cytochemical staining with Hoechst 33342 and flow cytometry.The expression of EGF and EGFR was detected by western blot.Results Metformin could inhibited the growth of A549 cells obviously in a dose-dependent manner.Flow cytometry analysis showed that when A549 cells were treated with metformin,the apoptosis rate in experimental groups were (10.65± 0.81)％,(21.56±1.21)％ respectively.Cell apoptosis with cell shrinkage,nuclear chromatin concentration and fragmentation were observed by cytochemical staining when treated with metformin.Western blot showed that the expression of EGF and EGFR were down regulated when the concentration of metformin was increasing.Conclusion Metformin could inhibit cell proliferation and induce apoptosis in lung adenocarcinoma A549 cells,which may be related to the down-regulation of EGF and EGFR protein expression.%目的 探讨降糖药物二甲双胍对人肺腺癌A549细胞表皮生长因子(Epidermal GrowthFactor,EGF)及其受体(Epidermal Growth Factor Receptor,EGFR)表达的影响.方法 用不同浓度二甲双胍作用于体外培养的人肺癌细胞后,MTT比色法检测其对A549细胞生长的抑制作用;流式细胞仪及Hoechst33342染色荧光显微镜检测细胞凋亡情况,免疫印迹法(Western blot)检测二甲双胍对肺腺癌细胞EGF及EGFR的表达.结果 二甲双胍明显抑制肺癌细胞的生长增殖,且呈剂量依赖性;流式细胞仪检测显示:随着二甲双胍作用浓度的增加,肺腺癌细胞的凋亡率也逐渐增加,实验组细胞凋亡率分别为(10.65±0.81)％、(21.56± 1.21)％;与对照组比较差异有统计学意义(P＜0.05);Hoechst33342染色可见实验组细胞皱缩,核染色质浓缩及核碎裂等现象;western blot显示:随着二甲双胍作用浓度的增大,EGF及EGFR表达呈现逐渐下调的趋势.结论 二甲双胍可抑制人肺腺癌A549细胞的增殖,并促进其凋亡,其机制可能与下调A549细胞内EGF及EGFR的表达密切相关.