MiR-382 inhibits proliferation and migration of triple negative breast cancer cell line 4T1 by mediating PGC-1α

Abstract

Objective To explore the effect of miR-382 down-regulating PGC-1α on the biological behaviors of triple negative breast cancer 4T1 cells. Methods ① After miR-382 mimics or inhibitory probe anti-miR-382 was transfected into 4T1 cells, the expression level of miR-382 was detected by qRT-PCR. The changes of PGC-1α expression at mRNA and protein levels were detected by qRT-PCR and Western blotting, respectively. ② Luciferase reporter gene assay was adopted to identify the binding site of miR-382 mimics to PGC-1α 3'UTR. ③miR-382 mimics or control miR were co-transfected into 4T1 cells with pCDNA3.1 or pCDNA-PGC1α, respectively. Transwell migration assay, CCK8 assay and subcutaneous xenografts and tail vein lung xenografts were respectively used to detect the changes in cell invasiveness, cell proliferation, and tumor growth and lung metastasis in mice. Results The expression of PGC-1α was significantly decreased in 4T1 cells after transfection with miR-382 mimics (P < 0.05), and it was obviously increased after transfection with anti-miR-382 (P < 0.05). There was a targeted regulatory core sequence (ACAACTT) of miR-382 and PGC-1α, and the site was at PGC-1α 3'UTR 565-582. Compared with the control +pCDNA3.1 group, the cell migration and proliferation activity of the miR-382+pCDNA3.1 group was significantly decreased, and the size of the 4T1 subcutaneous tumor and the area of metastatic tumor in the lung were notably decreased (P < 0.05). Compared with the control +pCDNA3.1 group, the cell migration and proliferation activity were significantly increased in the miR-382+pCDNA-PGC-1α group, and the size of 4T1 subcutaneous tumor and the area of metastatic tumor in the lung was significantly increased (P < 0.05); The antitumor effect of miR-382 was blocked by overexpression of PGC-1α. Conclusion MiR-382 inhibits the proliferation and lung metastasis of 4T1 cells by down-regulating PGC-1α, and the interaction site may be PGC-1α 3'UTR 565-582.

Keywords

• triple negative breast cancer
• microrna-382
• pgc-1α