miR-27a在三阴性乳腺癌中的表达及其对细胞耐药的影响

目的:探讨miR-27a在三阴性乳腺癌（triple-negative breast cancer，TNBC）中的表达及其对细胞耐药的影响。方法:首先通过QRT-PCR检测TNBC细胞株及非TNBC细胞株中miR-27a及P-gp的差异表达；上调TNBC细胞中的miR-27a的表达，通过CCK8检测细胞对化疗药物敏感性的变化。同时收集TNBC患者化疗前后血液标本，将其分为化疗敏感组和化疗耐药组，QRT-PCR检测患者血液标本中miR-27a及P-gp的表达，分析miR-27a与乳腺癌患者预后相关性。结果:miR-27a在TNBC细胞株中的表达明显低于非TNBC细胞株，上调TNBC细胞株中miR-27a的表达能够降低P-gp的表达，增加细胞对化疗药物的敏感性，此外TNBC组中miR-27a的表达与患者组织学分级、临床分期及淋巴结转移相关（P<0.05）；在非TNBC组中miR-27a的表达与患者临床病理特征无明显相关性（P均＞0.05）。结论:miR-27a参与调节TNBC细胞耐药，miR-27a可作为评估乳腺癌化疗敏感性及临床预后的潜在靶基因。

Expression of miR-27a in triple-negative breast cancer and its effect on drug resistance

Objective:To investigate the expression of miR-27a in triple-negative breast cancer and its effect on drug resistance.Methods:The expression of miR-27a and P-gp was detected by QRT-PCR in TNBC cell line and non-TNBC cell line in vitro.The expression of miR-27a in TNBC cells was up-regulated by transfected miR-27a mimics.At the same time to collect TNBC blood samples before and after chemotherapy of breast cancer，which can be divided into chemotherapy group and chemotherapy resistance group，the expression of miR-27a and P-gp were detected in blood samples by QRT-PCR，miR-27a and the prognosis of patients with breast cancer was analysed.Results:miR-27a expression in TNBC cell line was significantly lower than that of non-TNBC cells.Up-regulation of miR-27a expression in TNBC cell line can reduce the expression of P-gp，increase the sensitivity of cells to chemotherapeutic drugs.The expression of miR-27a in the TNBC group was related with histological grade，clinical stage and lymph node metastasis (P<0.05).In the non-TNBC group (non-triple-negative breast cancer) there was no significant correlation between the expression and clinicopathological characteristics in miR-27a (P＞0.05).Conclusion:miR-27a may be involved in the regulation of TNBC breast cancer cell resistance，and miR-27a may be a potential target gene for evaluating chemotherapy sensitivity and prognosis of breast cancer.