miR-493-5p attenuates the invasiveness and tumorigenicity in human breast cancer by targeting FUT4.

Breast cancer is a leading cause of cancer-related mortality among women. Altered fucosylation was found to be closely associated with tumorigenesis and metastasis of breast cancer. MicroRNAs (miRNAs) are important regulators of cell proliferation and metastasis, and aberrant miRNA expression has been observed in breast cancer. The present study aimed to evaluate the level of fucosyltransferase IV (FUT4) and miR-493-5p in breast cancer and investigate their relationship. In the present study, we demonstrated the differential expressional profiles of FUT4 and miR‑493-5p in 29 clinical breast cancer tissues, matched adjacent tissue samples and two breast carcinoma cell lines (MCF-7 and MDA-MB-231). Briefly, altered expression levels of FUT4 modified the invasive activities and tumorigenicity of the MCF-7 and MDA-MB-231 cells. Further study demonstrated that miR-493-5p plays a role as a suppressor in breast cancer cell invasion and tumorigenicity. Moreover, the expression levels of miR-493-5p were inversely proportional to those of FUT4 both at the mRNA and protein levels. Luciferase reporter assays confirmed that miR‑493-5p bound to the 3'-untranslated (3'-UTR) region of FUT4, and inhibited the expression of FUT4 in breast cancer cells. Taken together, our data suggest that FUT4 may have a potential role in the treatment of breast cancer, as well as miR-493-5p is a novel regulator of invasiveness and tumorigenicity of breast cancer cells through targeting FUT4. The miR-493-5p/FUT4 pathway has therapeutic potential in breast cancer.