miR-199a-3p在乳腺癌中的表达及其作用

背景与目的：多种微小RNA(microRNA，miRNA)在乳腺癌中异常表达，在乳腺癌的发生、发展中起重要作用。miRNA可能是治疗乳腺癌的新靶点。该研究旨在探讨miR-199a-3p在乳腺癌中的表达水平，及其对乳腺癌癌细胞增殖和凋亡的影响。方法：运用实时定量聚合酶链式反应(quantitative real-time polymerase chain reaction，QRT-PCR)检测乳腺癌患者癌组织、癌旁正常组织、人乳腺癌细胞和人乳腺细胞中miRNA-199a-3p的表达水平，miR-199a-3p mimic(或inhibitor)转染乳腺癌细胞MDA-MB-231过表达(或沉默)miR-199a-3p的表达后，通过MTT法检测细胞增殖能力，Hoechst染色法和caspase-3活力测试检测细胞凋亡情况。结果：相对癌旁正常组织和人正常乳腺细胞，miR-199a-3p在乳腺癌患者癌组织和人乳腺癌细胞中表达下调。在MDA-MB-231中转染miR-199a-3p mimic过表达miR-199a-3p可抑制细胞增殖，促进其凋亡；在MDA-MB-231中转染miR-199a-3p inhibitor沉默miR-199a-3p可促进细胞增殖，抑制其凋亡。结论：miR-199a-3p在乳腺癌中表达下调，并通过调节乳腺癌细胞增殖和凋亡发挥抑癌作用。

The expression of miR-199a-3p in breast cancer and its effect

Background and purpose:Multiple microRNAs (miRNAs) are abnormally expressed in breast cancer and play an important role in the regulation of breast cancer. miRNAs may be a new target for the treatment of breast cancer. This study aimed to investigate the expression of miR-199a-3p in breast cancer and the effect of miR-199a-3p on proliferation and apoptosis of breast cancer.Methods:Real-time PCR was used to test the expression of miR-199a-3p in breast cancer tissues, normal breast tissues, breast cancer cells and normal breast cells. Overexpression (or silencing the expression) of miR-199a-3p was conducted by transfecting MDA-MB-231 with miR-199a-3p mimics (or inhibitors). The proliferation of MDA-MB-231 was detected by MTT method. The apoptosis of MDA-MB-231 was investigated by Hoechst staining and caspase-3 activity assay kit.Results:Compared to corresponding non-tumor breast tissues (or normal breast cell HBL-100), lower levels of miR-199a-3p were expressed in breast cancer tissues or breast cancer cells. Overexpression of miR-199a-3p induced by miR-199a-3p mimic inhibited the proliferation and promoted the apoptosis of MDA-MB-231, while silencing the expression of miR-199a-3p induced by miR-199a-3p in-hibitor increased the proliferation and suppressed the apoptosis of MDA-MB-231.Conclusion:The expression of miR-199a-3p is lower in breast cancer, which shows its tumor suppression effect by regulating the proliferation and apoptosis of breast cancer cells.