Bioinformatics Prediction and In Vitro Analysis Revealed That miR‐17 Targets Cyclin D1 mRNA in Triple Negative Breast Cancer Cells

Breast cancer is one of the most prevalent malignancies among women worldwide. Triple negative breast cancer (TNBC) is a type of breast cancer in which estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER‐2) are not expressed. There is no targeted therapy for this type of cancer, and available therapies have poor therapeutic effects. Performing a preliminary research, we selected cyclin D1 (CCND1) gene of Wnt signaling pathway which is a target of miRNAs, a promising set of biomolecules in diagnosis and treatment of breast cancer. In this study using bioinformatic analyses, miR‐17 was selected as it targets the 3′UTR of CCND1 gene with the highest score. Luciferase assay results also confirmed the bioinformatic prediction. Decreased expression of miR‐17 in MDA‐MB‐231 cell line was observed using qRT‐PCR method. After lentiviral transduction of miR‐17 to the target cells, gene expression analysis showed decreased expression of CCND1 gene. We found miR‐17 as an attractive molecule that after intensive research can probably be used as a biomarker in TNBC.