MiR-6165 Dysregulation in Breast Cancer and Its Effect on Cell Proliferation and Migration

Background: ncRNAs have been identified as oncogenic drivers and tumor suppressors in any type of cancer. Although many classes of ncRNAs have been reported, most studies have been performed on microRNAs (miRNAs). miRNAs can regulate several target genes and affect important processes such as homeostasis, angiogenesis, cell proliferation, differentiation, and apoptosis. Located in the p75NTR gene, miR-6165 is known to induce apoptosis in colorectal cell lines, and one study proposed a tumor suppressive role in colorectal cancer. However, its mechanism of action in breast cancer is not completely understood yet. Therefore, this study aimed to consider the expression level and the effect of miR-6165 on the proliferation and migration in breast cancer. Material and methods: Fifty tumor and adjacent non-tumor tissues were examined in the study. miR-6165 levels were evaluated by qPCR in breast cancer cell lines and tumor tissues. Pre-mir-6165 was cloned in the pEGFPN1 vector. Next, human breast cancer MCF7 cells were cultured and pre-miR-6165 vector was transfected to breast cancer line. The effects on cell proliferation and migration were investigated with MTT assay and scratch test, respectively. Bioinformatics analysis was performed through enrichment and hub genes finding for miRNA targets. Results: miR-6165 was overexpressed in breast cancer tumor tissues and cell lines. High expression of miR-6165 was directly related to the metastasis. miR-6165 increased proliferation and migration in breast cancer cell line. Conclusions: miR-6165 may function as an oncomir and increase the growth and migration of cells which may consequently serve as a therapeutic goal for breast cancer.