微RNA-1299在三阴性乳腺癌中的表达及其对乳腺癌细胞迁移和侵袭的影响

Expression of microRNA-1299 in triple-negative breast cancer and its effects on migration and invasion of breast cancer cells

目的:探讨微RNA-1299(mircoRNA-1299,miR-1299)在三阴性乳腺癌(triple-negative breast cancer,TNBC)组织中的表达及其对TNBC细胞系MDA-MB-231和BT-549迁移和侵袭的影响。方法:选取河北医科大学第四医院2016年8月—2017年9月收治的126例乳腺癌患者的肿瘤组织标本及对应的癌旁组织,采用实时荧光定量PCR法检测Luminal型、人表皮生长因子受体2(human epidermal growth factor receptor2,HER-2)过表达型、TNBC型乳腺癌组织以及TNBC组织与其癌旁正常组织中miR-1299的表达水平;分析miR-1299表达与乳腺癌患者临床病理特征之间的关系。选用TNBC型MDA-MB-231和BT-549细胞并转染miR-1299-mimics,使miR-1299在MDA-MB-231和BT-549细胞中过表达;采用划痕愈合实验和Transwell小室实验检测miR-1299过表达对MDA-MB-231和BT-549细胞迁移和侵袭能力的影响;实时荧光定量PCR和蛋白质印迹法检测miR-1299过表达的MDA-MB-231和BT-549细胞中迁移和侵袭标志物基质金属蛋白酶2(matrix metalloproteinase 2,MMP2)和MMP17 mRNA及蛋白的表达水平。结果:miR-1299在TNBC型乳腺癌组织中呈低表达,而在Luminal型和HER-2过表达型中表达较高(P值均<0.01);与癌旁正常组织相比,TNBC组织中miR-1299的表达水平明显下调(P <0.01)。miR-1299的表达水平与乳腺癌患者的肿瘤浸润和淋巴结转移相关(P值均<0.05)。MDA-MB-231和BT-549细胞转染miR-1299-mimics后,2株细胞中miR-1299的表达水平明显升高(P值均<0.01)。miR-1299过表达后,MDAMB-231和BT-549细胞的迁移和侵袭能力明显减弱(P值均<0.001),侵袭和迁移标志物MMP2和MMP17 mRNA和蛋白的表达水平均明显下调(P值均<0.01)。结论:miR-1299在TNBC组织中表达下调,并可能抑制TNBC型乳腺癌细胞的侵袭和迁移。

Objective： To investigate the expression of microRNA-1299 （miR-1299） in triple-negative breast cancer （TNBC） and its effects on the migration and invasion of breast cancer MDA- MB-231 and BT-549 cells.Methods： A total of 126 breast cancer patients in the Fourth Hospital of Hebei Medical University from August 2016 to September 2017 were selected. The expression level of miR-1299 in different types of breast cancer [Luminal, human epidermal growth factor receptor 2 （HER-2） over-expressing, and TNBC] tissues and the TNBC-adjacent normal tissues was detected by real-time fluorescent quantitative PCR. The relationship between the clinicopathological parameters and miR-1299 expression was analyzed. TNBC-type MDA-MB-231 and BT-549 cells were selected to be transfected with miR-1299 mimics. The migration and invasion abilities of MDA-MB-231 and BT-549 cells after miR-1299 over-expression were detected by wound healing assay and Transwell assay, respectively. The expressions of matrix metalloproteinase 2 （MMP2） and MMP1 7 in MDA-MB-231 and BT-549 cells after miR-1299 over-expression were detected by real-time fluorescent quantitative PCR and Western blotting, respectively. Results： The expression level of miR-1299 was down-regulated in TNBC tissues, but was higher than that in Luminal and HER-2 over-expressing type of breast cancer tissues （both P 〈 0.01）. The expression level of miR-1299 in TNBC tissues was significantly lower than that in the adjacent normal tissues （P 〈 0.01）. The expression level of miR-1299 was associated with tumor infiltration and lymph node metastasis in breast cancer patients （both P 〈 0.05）. The expression level of miR-1299 was significantly increased after transfection of miR-1299 mimics in MDA-MB-231 and BT-549 cells （both P 〈 0.01）. The migration and invasion abilities of MDA-MB-231 and BT-549 cells decreased significantly （all P 〈 0.001）, and the expression levels of MMP2 and MMP1 7 mRNAs and proteins were significantly decreased after the over-expression of miR-1299 （all P 〈 0.01）. Conclusion： miR-1299 is down-regulated in TNBC tissues, and may inhibit the invasion and migration of TNBC cells.