MicroRNA-218-5p accelerates malignant behaviors of breast cancer through LRIG1.

OBJECTIVE

MicroRNAs play crucial roles in the pathogenesis of cancers. MiRNA-218-5p may act as either an oncogene or a tumor suppressor, but its role in the pathogenesis of Breast Cancer (BC) remains unclear.

METHODS

Infiltrative breast ductal carcinoma as well as corresponding adjacent normal samples were collected from 30 patients. Mimics and inhibitors of miRNA-218-5p or corresponding negative controls were transfected into BC cells. miRNA-218-5p expression was detected by quantitative PCR. The effects of miRNA-218-5p on the malignant behaviors of BC were assessed. Dual-luciferase reporter assay was employed to evaluate the binding of miRNA-218-5p to LRIG1.

RESULTS

BC tissues showed higher miRNA-218-5p expression as compared to the adjacent normal tissues. Ectopic miRNA-218-5p expression accelerated the cell cycle, cell growth and migration of BC, while repressed cell apoptosis. Interestingly, ectopic miRNA-218-5p expression down-regulated LRIG1 expression, and miRNA-218-5p could bind to LRIG1. Also, our study indicated that miRNA-218-5p up-regulated ErbB2 and EGFR expression by targeting LRIG1, suggesting that the LRIG1-mediated signaling pathway contributed to the pro-tumor effects of miRNA-218-5p on BC.

CONCLUSION

MiRNA-218-5p up-regulates ErbB2 and EGFR expression by suppressing LRIG1 expression, thus promoting the malignant behaviors of BC. miRNA-218-5p may exert a pro-tumor effect on BC and serve as a therapeutic target for BC treatment.