miR-21通过靶基因ZNF326调控乳腺癌细胞侵袭、迁移的分子机制研究

目的:探讨微小RNA-21（miR-21）靶向锌指蛋白326(ZNF326)对乳腺癌细胞侵袭、迁移的影响及其分子机制。方法:采用qRT-PCR与Western blot法检测乳腺癌细胞株HCC70、MDA-MB-231、BT549、MDA-MB-468与正常细胞株HBL-100中miR-21与ZNF326的表达。以miR-21表达量最高的乳腺癌HCC70细胞为研究对象，分为NC组、anti-miR-con组、anti-miR-21组、pcDNA-control组、pcDNA-ZNF326组；共转染分组为anti-miR-21+si-con组、anti-miR-21+si-ZNF326组。MTT法检测细胞增殖能力，Transwell迁移及侵袭实验检测细胞迁移及侵袭能力。双荧光素酶报告基因系统验证miR-21与ZNF326的靶向调控关系。Western blot法检测CDK1、MMP-2蛋白的表达。结果:与正常细胞株HBL-100相比，乳腺癌细胞株HCC70、MDA-MB-231、BT549、MDA-MB-468中miR-21高表达，ZNF326 mRNA及蛋白表达水平均显著下降；分别与anti-miR-con组、pcDNA-control组比较，anti-miR-21组与pcDNA-ZNF326组HCC70细胞增殖能力显著下降，细胞迁移及侵袭能力明显降低，CDK1、MMP-2的表达水平明显降低；双荧光素酶实验结果表明miR-21能靶向结合ZNF326的3' UTR并调控其表达；与anti-miR-21+si-con组相比，anti-miR-21+si-ZNF326组HCC70细胞增殖、迁移及侵袭能力均明显增强，促进CDK1、MMP-2表达。结论:miR-21可靶向抑制ZNF326基因的表达，进而促进乳腺癌细胞增殖、迁移及侵袭。

Molecular mechanism of miR-21 regulating invasion and migration of breast cancer cells via targeting ZNF326 gene

Objective:To investigate the effect of microRNA-21（miR-21) targeting zinc finger protein 326（ZNF326) on invasion and migration of breast cancer cells and its molecular mechanism.Methods:The expressions of miR-21 and ZNF326 in breast cancer cell lines HCC70,MDA-MB-231,BT549,MDA-MB-468 and normal cell line HBL-100 were detected by qRT-PCR and Western blot.The breast cancer HCC70 cells with the highest expression of miR-21 were divided into NC group,anti-miR-con group,anti-miR-21 group,pcDNA-control group and pcDNA-ZNF326 group.The co-transfection group was anti-miR-21+si-con group,anti-miR-21+si-ZNF326 group.Cell proliferation was detected by MTT assay,and cell migration and invasion were detected by Transwell migration and invasion assay.The dual luciferase reporter gene system verified the targeted regulatory relationship between miR-21 and ZNF326.Western blot was used to detect the expression of CDK1 and MMP-2 proteins.Results:Compared with the normal cell line HBL-100,miR-21 was highly expressed in breast cancer cell lines HCC70,MDA-MB-231,BT549 and MDA-MB-468,and the expression of ZNF326 mRNA and protein was significantly decreased.Compared with anti-miR-con group and pcDNA-control group,the proliferation of HCC70 cells in anti-miR-21 group and pcDNA-ZNF326 group was significantly decreased,cell migration and invasion ability were significantly decreased,and the expression level of CDK1 and MMP-2 were significantly decreased.Dual luciferase assays showed that miR-21 could target ZNF326 and regulated its expression.Compared with the anti-miR-21+si-con group,the proliferation,migration and invasion of HCC70 cells in the anti-miR-21+si-ZNF326 group were significantly enhanced,and the expression of CDK1 and MMP-2 was promoted.Conclusion:miR-21 can target the inhibition of ZNF326 gene expression and promote breast cancer cell proliferation,migration and invasion.