微小RNA-34a在乳腺癌组织的表达及其对乳腺癌细胞的生物学影响

Expression of microRNA-34a in breast cancer and its influence on biological behaviors of breast cancer cells

目的 观察微小RNA（miRNA,miR）-34a在乳腺癌中的表达以及对乳腺癌细胞生长、迁移和侵袭能力的影响.方法 采用反转录-聚合酶链反应（RT-PCR）法检测乳腺癌组织和正常乳腺组织中miR-34a的表达水平,分析miR-34a的表达与乳腺癌患者临床病理特征的相关性.在乳腺癌细胞MDA-MB-453中转染miR-34a模拟物和miR-34a抑制物,RT-PCR法检测转染后的乳腺癌细胞株中miR-34a表达水平,细胞计数试剂盒（CCK-8）法检测乳腺癌细胞的生长活性,Transwell法和细胞划痕实验分别检测乳腺癌细胞的迁移和侵袭能力.结果 miR-34a在乳腺癌组织和正常组织中的相对表达水平为0.433±0.059和1.040 ±0.072,两者差异有统计学意义（P＜0.05）,且miR-34a的表达水平与乳腺癌患者的临床分期和淋巴结转移有关.转染miR-34a模拟物后乳腺癌细胞MDA-MB-231的生长活性显著降低,MDA-MB-231和MCF-7细胞的迁移能力[（35.1±2.0）％、（28.7±1.8）％]和侵袭能力（41.6 ±3.9、39.4±4.3）显著降低,差异均有统计学意义（P＜0.05）.结论 miR-34a在乳腺癌中表达显著下调,其表达水平与乳腺癌患者的临床分期和淋巴结转移有关,过表达miR-34a可抑制乳腺癌细胞的生长、迁移和侵袭能力.

Objective To investigate the expression of microRNA （miRNA,miR）-34a in breast cancer and its influence on cell proliferation,cell invasiveness and migration capability of breast cancer cells.Methods The expression of miR-34a in breast cancer tissues and cells was measured by reverse transcriptase-polymerase chain reaction （RT-PCR） and the correlation of miR-34a expression and the clinical characteristics of breast cancer patients was analyzed.MiR-34a mimics and miR-34a inhibitor were transfected into breast cancer cells.The cell counting kit-8 （CCK-8） method was used to detect the cell proliferation of breast cancer cells,then we detected the cell migration and invasion ability of breast cancer cells transfected by miR-34a mimics and miR-34a inhibitor.Results The relative expression of miR-34a in breast cancer tissues and normal tissues was 0.433 ± 0.059 and 1.040 ± 0.072 respectively （P 〈 0.05）,and the expression level of miR-34a in breast cancer tissues was related to clinical stages and lymphatic metastasis.The overexpression of miR-34a in breast cancer cells could inhibit cell proliferation,migration [（35.1 ± 2.0） % and （28.7 ± 1.8） %] and invasion （41.6 ± 3.9 and 39.4 ± 4.3,P 〈0.05）.Conclusion miR-34a is down-regulated in breast cancer,and its expression level is related to clinical stages and lymphatic metastasis.MiR-34a may be involved in the progress of breast cancer by inhibiting the cell proliferation,migration and invasion of breast cancer cells.