miR-34a靶向调控Akt/Bcl-2对乳腺癌细胞多柔比星耐药性的影响  

Effects of miR-34a on doxorubicin resistance in breast cancer by targeting Akt/Bcl-2

作　　者：吴金枝 马虎 曹云亮 张川骎 苟小霞 WU Jinzhi;MA Hu;CAO Yunliang;ZHANG Chuanqin;GOU Xiaoxia(Department of Head and Neck Oncology,the Second Affiliated Hospital of Zunyi Medical University,Zunyi 563003,China;Department of Head and Neck Oncology,the Affiliated Hospital of Zunyi Medical University)

机构地区：[1]遵义医科大学第二附属医院头颈肿瘤科,563003 [2]遵义医科大学附属医院头颈肿瘤科

出　　处：《天津医药》2022年第1期41-45,共5页Tianjin Medical Journal

基　　金：遵义市汇川区科技局项目[遵汇科合(2017)16号]。

摘　　要：目的探讨miR-34a的表达水平对乳腺癌细胞多柔比星(DOX)耐药性的影响及其分子机制。方法通过实时荧光定量PCR(qPCR)法检测miR-34a在乳腺癌细胞(MCF-7)和DOX耐药细胞株(MCF-7/ADR)中的表达,通过转染miR-34a mimics或者miR-34a inhibitor调控其表达水平;CCK-8法筛选DOX处理细胞的半数有效抑制浓度(IC50),检测细胞存活率;流式细胞术检测细胞凋亡情况;ENCORI网站预测miR-34a靶基因Akt的结合位点;Western blot检测蛋白激酶B(Akt)、Bcl-2及Bax蛋白的表达。结果与MCF-7细胞株相比,MCF-7/ADR细胞株中miR-34a的基础表达水平降低(P<0.01)。与NC inhibitor组相比,miR-34a inhibitor组中miR-34a表达水平降低(P<0.01)。DOX处理MCF-7及MCF-7/ADR细胞的IC50分别为0.895 mg/L和13.607 mg/L。miR-34a与Akt基因3′UTR区可能存在结合位点。经DOX处理后,miR-34a inhibitor组细胞存活率显著升高,细胞凋亡率降低,p-Akt/Akt和Bcl-2/Bax蛋白表达水平升高(P<0.05)。与NC mimics组相比,miR-34a mimics组中miR-34a表达水平升高(P<0.01)。经DOX处理后,miR-34a mimics组中细胞存活率降低,细胞凋亡率升高,p-Akt/Akt和Bcl-2/Bax蛋白水平降低(P<0.01)。结论 miR-34a在MCF-7/ADR中的表达下调,可能通过激活Akt/Bcl-2通路,减少细胞凋亡,进而增强细胞对DOX的耐药性。Objective To investigate the effect of miR-34 a expression level on doxorubicin(DOX) resistance in breast cancer cells and its molecular mechanism.Methods The expression levels of miR-34 a in breast cancer cells(MCF-7) and DOX resistant cells(MCF-7/ADR) were detected by qPCR,and their expression levels were regulated by transfection of miR-34 a mimics or miR-34 a inhibitor.The half effective inhibitory concentration(IC_(50)) of DOX treated cells was screened by CCK-8 method.CCK-8 method was used to detect cell survival rate.The percentage of apoptotic cells was detected by flow cytometry.ENCORI website predicted the binding site of miR-34 a target gene Akt.The expressions of target gene protein kinase B(Akt),Bcl-2 and Bax proteins were detected by Western blot assay.Results The expression of miR-34 a in MCF-7/ADR was significantly lower than that in MCF-7 cells(P<0.01).Compared with the NC inhibitor group,the expression level of miR-34 a decreased in the miR-34 a inhibitor group(P <0.01).The values of IC_(50) of MCF-7 and MCF-7/ADR cells treated with DOX were 0.895 and 13.607 mg/L,respectively.There may be a binding site between miR-34 a and the 3’UTR region of Akt gene.After DOX treatment,the survival rate increased significantly,the apoptosis rate decreased,and the levels of p-Akt/Akt and Bcl-2/Bax protein increased in the miR-34 a inhibitor group(P<0.05).Accordingly,compared with the NC mimics group,the expression level of miR-34 a increased in the miR-34 a mimics group(P<0.01).After treatment with DOX,the cell survival rate decreased,the apoptosis rate increased,and the levels of p-Akt/Akt and Bcl-2/Bax protein decreased in the miR-34 a mimics group(P<0.01).Conclusion The down-regulated expression of miR-34 a in MCF-7/ADR cells may reduce cell apoptosis by stimulating Akt/Bcl-2 signal,thus enhancing the resistance of cells to DOX.

关 键 词：微RNAS 乳腺肿瘤 多柔比星 抗药性 肿瘤 细胞凋亡 原癌基因蛋白质C-BCL-2 原癌基因蛋白质c-akt MIR-34A 

分 类 号：R737.9[医药卫生—肿瘤]