雌二醇诱导子宫内膜癌细胞产生的VEGF和bFGF对MAPK通路的影响

Estradiol activates MAPK signaling pathway by estrogen induced VEGF and bFGF in endometrial cancer cells

目的 探讨雌二醇诱导子宫内膜癌细胞系Ishikawa细胞生成的血管内皮生长因子（VEGF）和碱性成纤维细胞生长因子（bFGF）对有丝分裂原活化蛋白激酶（MAPK）通路中主要基因蛋白的影响.方法 实验分为4组：雌二醇组（E2组,加入1 μmol/L的雌二醇作用30 min）,抑制剂组[包括Bibf1120组：加入10 μmol/L的VEGF受体抑制剂——Bibf1120; Ponatinib组：加入2.5 μmol/L的bFGF受体抑制剂——Ponatinib; U0126组：加入10μmol/L的MAPK激酶（MEK）特异性抑制剂——U0126.各组均预处理1 h],抑制剂＋E2组（包括Bibf1120＋E2组、Ponatinib＋E2组和U0126＋E2组,各抑制剂预处理1h后,加入1μmol/L的雌二醇作用30 min）;对照组（仅加入无血清DMEM培养基）.（1）以不同浓度（分别为0.01、0.1、1、10、100μmol/L）雌二醇作用于Ishikawa细胞后,采用蛋白印迹法检测磷酸化细胞外信号调节激酶1/2（p-ERK1/2）蛋白活化水平.（2）采用荧光定量PCR技术检测各组细胞中VEGF、bFGF、MEK1/2、ERK1/2mRNA的表达,蛋白印迹法检测各组细胞中VEGF、bFGF蛋白的表达及磷酸化NEK1/2（p-MEK1/2）、p-ERK1/2蛋白活化水平,流式细胞仪检测各组细胞的细胞周期比例,体外穿膜实验检测各组细胞的迁移能力.结果 （1）不同浓度（分别为0.01、0.1、1、10、100 μmo1/L）的雌二醇作用30 min后Ishikawa细胞中p-ERK1/2蛋白的活化水平分别为0.16±0.03、0.10±0.03、0.41±0.04、0.19±.0.03、0.19±0.03,均明显高于对照组的0.05±0.00 （P＜0.05）,且雌二醇浓度为1μmol/L时其活化水平最高.（2）E2组细胞中VEGF、bFGF mRNA及蛋白的表达水平均高于对照组,分别与对照组比较,差异均有统计学意义（P＜0.05）;Bibf1120＋E2组细胞中VEGF mRNA及蛋白的表达水平分别与E2组比较,差异均有统计学意义（P＜0.05）.E2组MEK1/2、ERK1/2mRNA及p-MEK1/2、p-ERK1/2蛋白活化水平均显著高于对照组（P＜0.05）;Bibf1120＋E2组、Ponatinib＋E2组、U0126＋E2组细胞中MEK1/2、ERK1/2mRNA及p-MEK1/2、p-ERK1/2蛋白活化水平均低于E2组（P＜0.05）.E2组G1期及S期细胞比例分别为（53.6±3.2）％和（29.2±4.2）％,分别与对照组的（65.1±2.6）％和（20.2±1.9）％比较,差异均有统计学意义（P＜0.05）;U0126＋E2组、Bibf1120＋E2组、Ponatinib＋E2组G1期细胞比例分别为（66.8±2.6）％、（63.1±2.6）％和（63.3±0.4）％,S期细胞比例分别为（25.4±1.9）％、（25.0±3.8）％和（23.8±0.5）％,分别与E2组比较,差异均有统计学意义（P＜0.05）;U0126＋E2组分别与Bibf1120＋E2组、Ponatinib＋E2组比较,差异也均有统计学意义（P＜0.05）.E2组穿过微孔的细胞数为（110±17）个,与对照组的（65±8）个比较,差异有统计学意义（P＜0.05）;U0126＋E2组、Bibf1 120＋E2组、Ponatinib＋E2组穿过微孔的细胞数分别为（28±4）、（38±5）、（42±6）个,分别与E2组比较,差异均有统计学意义（P＜0.05）;U0126＋E2组分别与Bibf1 120＋E2组、Ponatinib＋E2组比较,差异也均有统计学意义（P＜0.05）.结论 雌二醇通过非基因转录效应产生的VEGF、bFGF可以激活MAPK通路,促进子宫内膜癌的发生、发展.

Objective To explore the effects of mitogen-activated protein kinase （MAPK） pathway by estradiol induced vascular endothelial growth factor （VEGF） and basic fibroblast growth factor （bFGF） in endometrial cancer Ishikawa cells.Methods The experiments were divided into 4 groups：E2 group （Ishikawa cells treated with 1 p mol/L estradiol for 30 minutes）; inhibitor group：including Ishikawa cells treated with 10 μmol/L Bibf1 120 （Bibf1 120 group）,or treated with 2.5 μmol/L Ponatinib （Ponatinib group）,or treated with 10 p mol/L U0126 （U0126 group） for 60 minutes; inhibitor ＋ E2 group：including Ishikawa cells treated with 10 μmol/L Bibf1120 （Bibf1120 ＋ E2 group）,or treated with 2.5 μmol/L Ponatinib （Ponatinib ＋ E2 group）,or treated with 10 μmol/L U0126 （U0126＋ E2 group） for 60 minutes following incubation with 1 μmol/L estradiol for 30 minutes; control group：only adding the culture medium without serum DMEM.（1） Western blot analysis was used to detect phosphorylation extracellular signal-regulated kinase 1/2（p-ERK 1/2） protein expression with stimulation in different concentrations of estradiol （0.01,0.1,1,10,100 μmol/L）.（2） Quantitative fluorescent reverse transcription （qRT）-PCR and western blot analysis was used to test the level of mRNA and protein of VEGF,bFGF,MAPK kinase 1/2 （MEK1/2）,extracellular signal-regulated kinase 1/2 （ERK1/2）,p-ERK1/2 and phosphorylation MEK1/2 （p-MEK1/2）.Flow cytometry were used to examine the cell cycle,and transwell chamber assay were used to detect the cell migration in different groups.Results The expression of the p-ERK1/2 protein at 0.01,0.1,1,10,100 μ mol/L were 0.16±0.03,0.10±0.03,0.41 ±0.04,0.19±0.03,0.19±0.03,there were significantly higher than that in control group（0.05±0.00,P＜0.05）,and which was more obvious at the concentration of 1 μmol/L estradiol.The expression level of VEGF,bFGF mRNA and protein in E2 group were higher than those in the control group （P＜O.05）.VEGF mRNA and protein in Bibf1120＋E2 group were higher than those in E2 group.The expression of MEK1/2,ERK1/2 mRNA protein in E2 group were higher than those in control group （P＜0.05）.The expression of MEK1/2,ERK1/2 mRNA or p-MEK1/2,p-ERK1/2 protein in Bibf1120 ＋ E2 group,Ponatinib＋E2 group or U0126＋E2 group were lower than those in E2 group（all P＜0.05）.Percentage of G1 phase [（53.6±3.2）％] and S phase[（29.2±4.2）％] in E2 group was significantly different with those in control group respectively（P＜0.05）.Percentage of G1 phase[（66.8±2.6）％,（63.1±2.6）％ and （63.3±0.4）％] and S phase [（25.4±1.9）％,（25.0±3.8）％ and（23.8±0.5）％] in U0126＋E2 group,Bibf1120＋E2 group or Ponatinib ＋E2 group was also significantly different with those in control group （all P＜0.05）; percentage of G1 phase and S phase in U0126＋E2 group was significant difference with those in Bibf1120＋E2 group or ponatinib＋E2 group （P＜0.05）.The number of cell colony in E2 group （110± 17） was more than those in control group （65±8） ;the number of cell colony in U0126＋E2 group（28±4）,Bibf1120＋E2 group（38±5） or Ponatinib＋E2group（42±6） were significant different with those in E2 group （P＜0.05）,the number of cell colony in U0126＋E2 group was significant difference with those in Bibf1 120＋E2 group or Ponatinib＋E2 group （all P＜0.05）.The results shown that the abilities of proliferation and cell migration were significantly increased in cells after estradiol stimulation.Conclusion Estradiol inducing the production of VEGF and bFGF could activate MAPK pathway through ER-independent manner,further promote development.