MiR-630 inhibits cells migration and invasion by targeting SOX4 in triple-negative breast cancer

Objective: To verify whether miR-630 could inhibit Triple-negative Breast Cancer (TNBC) cell line MDwA-MB-231 cells migration and invasion by targeting SOX4 in TNBC. Methods: Normal breast tissue and breast cancer tissue (44 case of TNBC, 115 case of NTNBC) from patients undergoing breast cancer resection were collected. RT-PCR was used to test the expression of miR-630, miR-21, miR-134, miR-200a, miR-381, miR-1228 and SOX4 mRNA in the tissues; Western blot were used to test the expression of MMP-2, MMP-9, COL1A1, COL1A5 and SOX4 in the tissues. In vitro experiment, after miR-630 mimics was transfected into MDA-MB-231 cells, wound healing assay were employed to test the migratory ability of MDA-MB-231 cells, transwell chambers were used to test the invasion ability of cells, Western blotting were used to investigate the expressions of COL1A1, COL1A5, MMP2, MMP-9 and SOX4. Luciferase assay was used to confirmed whether SOX4-3'-UTR the target gene of miR-630. SOX4 over-expression plasmid was transfected to further confirm miR-630 played its role by down-regulation of SOX4. Results: Compared with normal breast tissue, the expression of miR-630 was decreased in the TNBC tissue (P<0.01); meanwhile COL1A1, COL1A5, MMP-2, MMP-9 and SOX4 was significantly increased (P<0.01); the relative expression of miR-630 level was negatively correlated with SOX4 mRNA (P<0.01). In vitro experiment, compared with the mimic control, the migration and invasion activity of MDA-MB-231 cells was decreased after transfection of miR-630 mimics (P<0.01); meanwhile, miR-630 mimic also decreased the expression of SOX4 in MDA-MB-231 cells (P<0.00). The Luciferase activity of the SOX4-3'-UTR plasmid was significantly suppressed by miR-630 (P<0.00). Over expression of SOX4 could partly abrogated miR-630 mediated inhibition of MDA-MB-231 migration and invasion. Conclusion: In TNBC tissue, the expression of miR-630 decreased; miR-630 inhibits TMDA-MB-231 cells migration and invasion by targeting SOX4-3'-UTR.