miR-622 Induces Breast Cancer Cell MCF-7 Proliferation, Migration, and Invasion by Directly Negatively Targeting EYA1

Abstract

Breast cancer is the most common female cancer in the world. Breast cancer patients are currently treated with a combination of surgery, chemotherapy, radiotherapy, and targeted therapy, but the 5-year overall survival rate is still low. Therefore, we plan to explore the potential interaction mechanism between miR-622 and EYA1 in the breast cancer cells and their effect on proliferation, migration, and invasion of breast cancer, to lay a foundation for the gene therapy of breast cancer and improve the therapeutic effect. This study found that miR-622 was highly expressed in breast cancer cell lines, while EYA1 was poorly. In MCF-7 cell line, miR-622 had the highest expression level, while EYA1 had the lowest. Besides, the bioinformatics analysis showed that EYA1 possesses putative miR-622 binding sites within its 3 ${}^{\prime }$ UTR. The increased miR-622 significantly enhanced the proliferation, migration, and invasion of MCF-7 cell line and inhibited luciferase reporter activity in the 3 ${}^{\prime }$ UTR of EYA1-WT. When upregulating the expression of miR-622, the mRNA and protein expression levels of EYA1 were significantly decreased. We also found that the silencing of EYA1 promoted the proliferation, migration, and invasion of breast cancer MCF-7 cell line. These results indicate that miRNA-622 plays a tumor-promoting role in breast cancer through targeted negative regulation of EYA1, suggesting that miRNA-622 may become a potential target for breast cancer treatment.