To explore the effect of miR-106a in breast cancer cell behavior and sensitivity to chemotherapeutic agents. Tumor tissue and adjacent normal tissue were derived from 40 breast cancer patients, and miR-106a expression was measured by reverse transcription-qPCR. Breast cancer cells, MDA-MB-231 and MCF-7, were treated with miRNA-106a mimic (MM) or miRNA-106a inhibitor (MI) and negative controls. Cell proliferation was measured by MTT assay. Clonogenicity was measured by colony-forming assay. Cell migration and invasion ability were measured by scratch test and transwell assay, respectively. Apoptosis was determined by flow cytometry, and chemosensitivity to cisplatin was measured by MTT assay. Finally, protein expression of p53, Bax, Bcl-2, RUNX3, and ABCG2 was quantified by western blot. miR-106a expression was significantly upregulated in human breast cancer tissue relative to adjacent normal tissue. Upregulation of miR-106a enhanced breast cancer cell proliferation, colony-forming capacity, migration, and invasion of cultured breast cancer cells. Additionally, miR-106a overexpression significantly decreased breast cancer cell apoptosis and sensitivity to cisplatin. Finally, we showed miR-106a overexpression upregulated the levels of Bcl-2 and ABCG2, and downregulated the expression of P53, Bax, and RUNX3. miR-106a promotes breast cancer cell proliferation and invasion through upregulation of Bcl-2, ABCG2, and P53, and downregulation of Bax and RUNX3.
Keywords: breast cancer; cell behavior; chemosensitivity; miR-106a.