miR－193b 体外协同增强多柔比星对乳腺癌细胞的抗肿瘤效应

摘要

AIM:To investigate the effect of microRNA ( miR)-193b on doxorubicin therapy in breast cancer in vitro.METHODS:miR-193b level in plasma was detected by real-time PCR in the patients with breast cancer or the healthy controls.MTT assay was performed to measure the inhibitory effect of miR-193b plus doxorubicin on the growth of MDA-MB-231 cells.Bioinformatics, real-time PCR and Western blot were performed to determine whether the expression of Mcl-1 was regulated by miR-193b.Mcl-1 expression vector was constructed , and the role of Mcl-1 vector toward miR-193b plus doxorubicin-induced cytotoxicity in MDA-MB-231 cells was observed by MTT assay .RESULTS:Down-regulation of miR-193b was found in breast cancer patients .The miR-193b plus doxorubicin group showed a higher growth inhibition than cisplation group in MDA-MB-231 cells.The expression of Mcl-1 at both mRNA and protein levels was down-regulated after miR-193b transfection.The growth inhibition of MDA-MB-231 cells treated with miR-193b plus doxorubicin was sig-nificantly decreased after the transfection of Mcl-1 expression vector.CONCLUSION: miR-193b sensitizes doxorubicin-induced cytotoxicity by targeting Mcl-1 in breast cancer .%目的：研究微小RNA（ microRNA，miR）－193b是否能增强多柔比星对乳腺癌细胞的杀伤效力及机制。方法：用real－time PCR方法检测乳腺癌患者及健康对照者血浆中的miR－193b表达水平。 MTT法检测miR－193b联合多柔比星对乳腺癌细胞系MDA－MB－231的杀伤效力。利用生物信息学、real－time PCR及Western blot 方法验证miR－193b是否调节乳腺癌细胞Mcl－1的表达。构建Mcl－1真核表达载体，MTT法检测Mcl－1表达载体转染对miR－193b联合多柔比星治疗乳腺癌疗效的影响。结果：乳腺癌患者血浆中miR－193b表达水平显著低于对照组。 miR－193b联合多柔比星治疗组对MDA－MB－231细胞的杀伤效力显著高于多柔比星单治疗组。 miR－193b转染后，MDA－MB－231细胞Mcl－1的mRNA及蛋白表达水平均下降。 miR－193b联合多柔比星在Mcl－1表达载体转染后对MDA－MB－231细胞的杀伤活性显著低于未转染Mcl－1表达载体的miR－193b联合多柔比星组。结论： miR－193b通过靶向于Mcl－1增强多柔比星对乳腺癌细胞的杀伤效力。