ELF4通过激活Akt通路促进胰岛素瘤细胞增殖并抑制细胞凋亡  

ELF4 promotes proliferation and inhibits apoptosis of human insulinoma cells by activating Akt signaling

作　　者：卫国红[1] 王利[2] 万学思[1] 谭泳谣 WEI Guohong;WANG Li;WAN Xuesi;TAN Yongyao(Department of Endocrinology,First Affiliated Hospital of Sun Yat-sen University,Guangzhou 510080,China;Department of Healthcare,First Affiliated Hospital of Sun Yat-sen University,Guangzhou 510080,China;Zhongshan School of Medicine,Sun Yat-sen University,Guangzhou 510080,China)

机构地区：[1]中山大学附属第一医院内分泌科,广东广州510080 [2]中山大学附属第一医院保健科,广东广州510080 [3]中山大学中山医学院,广东广州510080

出　　处：《南方医科大学学报》2021年第9期1329-1333,共5页Journal of Southern Medical University

基　　金：广东省自然科学基金(2018A030313599,2016A030313239)。

摘　　要：目的探索ELF4促进胰岛素瘤细胞增殖与抗凋亡的作用及其机理。方法利用逆转录病毒载体系统,构建稳定高表达ELF4的胰岛素瘤细胞BON-ELF4,以及载体对照组细胞BON-Vector。采用MTT法检测胰岛素瘤细胞BON-ELF4和BONVector各组细胞的生长情况。采用0.1μmol/L化疗药物表阿霉素处理BON-ELF4和BON-Vector细胞24 h后,检测细胞凋亡相关指标,采用免疫印迹法检测各组肿瘤细胞中凋亡通路关键因子caspase-9,caspase-8和PARP切割带的表达水平;采用Annexin V-FITC/PI双染色结合流式细胞术分析各组细胞凋亡情况。采用免疫印迹法检测胰岛素瘤细胞BON-ELF4和BONVector细胞中Akt磷酸化水平。结果免疫印迹法检测结果显示,BON-ELF4细胞中ELF4蛋白表达量高于对照组细胞BONVector(P=0.013),稳定高表达外源性ELF4蛋白的细胞系BON-ELF4构建成功。稳定高表达ELF4的细胞系BON-ELF4生长明显较快(P<0.05)。相比较于载体对照组BON-Vector,BON-ELF4细胞在0.1μmol/L表阿霉素处理24 h后caspase-8,caspase-9的蛋白前体降低,而caspase-8,caspase-9切割成熟体升高(P<0.05);同时,相应的PARP切割带随着ELF4的高表达而降低(P<0.05);流式细胞术检测结果显示,22.90%的载体对照组BON-Vector细胞呈现出Annexin V阳性、PI阴性的早期凋亡结果,6.03%的BON-ELF4细胞组呈现出Annexin V阳性、PI阴性的早期凋亡结果。外源高表达ELF4的肿瘤细胞中Akt的磷酸化显著升高(P<0.05),而Akt总蛋白的水平基本未受影响(P>0.05)。结论ELF4能通过激活Akt通路而促进胰岛素瘤细胞增殖和抗凋亡。Objective To investigate the effect of overexpression of the oncogenic transcription factor ELF4 on proliferation and apoptosis in human insulinoma cells and explore the underlying mechanism.Methods A human insulinoma BON cell line with stable overexpression of ELF4(BON-ELF4 cells)was constructed using a recombinant retrovirus vector and the expression of ELF4 protein was verified using Western blotting.MTT assay was used to assess the proliferation of BON-ELF4 cells and BON-Vector cells,and the cell apoptosis induced by treatment with epirubicin(0.1μmol/L for 24 h)was analyzed by detecting the expressions of cleaved caspase-8,caspase-9,and PARP using Western blotting.Flow cytometry with Annexin VFITC/PI staining was performed to analyze the numbers of apoptotic BON-Vector or BON-ELF4 cells.The expressions of phosphorylated Akt and total Akt in the cells were detected using Western blotting.Results BON-ELF4 cell line with stable overexpression of ELF4 was successfully established.ELF4 overexpression significantly promoted the proliferation(P<0.05)and obviously suppressed epirubicin-induced apoptosis in BON cells,resulting also in significantly reduced expressions of cleaved caspase-8,caspase-9 and PARP(P<0.05).The results of flow cytometry showed a significantly lower apoptotic rate in BON-ELF4 cells than in BON-Vector cells following epirubicin treatment(6.03%vs 22.90%).The phosphorylation levels of Akt(Thr308 and Ser473)were significantly increased(P<0.05)while the level of total Akt remained unchanged(P>0.05)in ELF4-overexpressing cells.Conclusion ELF4 overexpression enhances the proliferation and suppresses apoptosis of insulinomas cells by activating Akt signaling.

关 键 词：ELF4 胰岛素瘤细胞 AKT信号通路 

分 类 号：R736.7[医药卫生—肿瘤]