Overexpression of microRNA-365 inhibits breast cancer cell growth and chemo-resistance through GALNT4.

A role of microRNA-365 (miR-365) in the carcinogenesis of breast cancer remains undetermined. In the current study, we addressed this question.We examined the levels of miR-365 in breast cancer tissue, compared to the paired adjacent non-tumor breast tissue from the patients. We also examined the effects of miR-365 modification on the breast cancer growth and sensitivity to Fluorouracil, as well as the underlying mechanisms.The miR-365 levels in breast cancer tissue were significantly lower than those in control normal breast tissues. Transfection with the miR-365 mimic decreased the breast cancer cell growth and increased their sensitivity to Fluorouracil, while transfection with the antisense of miR-365 (as-miR-365) increased breast cancer cell growth and decreased their sensitivity to Fluorouracil. Bioinformatics analyses showed that GALNT4 was a potential target gene of miR-365. The luciferase activities assay and Western blot verified that miR-365 targeted GALNT4 mRNA to modulate its protein levels.Our study suggests that downregulation of miR-365 may facilitate carcinogenesis of breast cancer cells via GALNT4, and thus miR-365 appears to be a promising target for breast cancer therapy.