miR-155-5p Promotes Invasion and Migration of MCF-7 Breast Cancer Cell by Down-regulating SOX1 / 华中科技大学学报(医学版)

ABSTRACT

Objective To examine the mechanism by which miR-155-5p regulates sex determining region Y-boc 1(SOX1) expression in breast cancer cell line MCF-7,and to investigate the effect of miR-155-5p on the invasion and metastasis of these cells.Methods After up-regulation or down-regulation of the expression of miR-155-5p in MCF-7 cells,the transwell assay was performed to detect the invasive and migrating ability of MCF-7 cells;SOX1 mRNA expression and protein levels were detected by real-time PCR and Western blot,respectively;immunofluorescence was used to test the distribution and levels of SOX1 pro-tein,and dual luciferase reporter experiments to discover the binding of miR-155-5p to the 3′-UTR region of SOX1 mR-NA.Results Up-regulating the expression of miR-155-5p could enhance the migrating and invasive ability of MCF-7 cells and simultaneously decrease the mRNA and protein levels of SOX1(P <0.05).On the contrary,inhibition of miR-155-5p depressed the invasion and migration of MCF-7 cells and increased the expression of SOX1(P < 0.05).Dual luciferase reporter experi-ments confirmed that miR-155-5p could bind to the specific sequence in the 3′-UTR of SOX1 mRNA and play a role of regula-tor.Conclusion miR-155-5p promotes the invasion and migration of breast cancer cell line MCF-7 via inhibiting the expression of SOX1.