miR-28-3p promotes the malignant biological behaviors of triple negative breast cancer MDA-MB-468 cells via inhibiting BIN1 / 中国肿瘤生物治疗杂志

ABSTRACT

@# Objective: To study the miR-28-3p expression in triple negative breast cancer (TNBC) tissues and cell lines, and explore its effect on the malignant biological behaviors of MDA-MB-468 cells. Methods： ：Tumor tissues and matched para-cancerous tissues were collected from 83 TNBC patients, who underwent tumor resection and pathological confirmation in the Fourth Hospital of Hebei Medical University between Jan. 2013 and Jan. 2014. TNBC cell lines (MDA-MB-468, HCC-1937, MDA-MB-231, MDA-MB436, MDA-MB-453) and human normal breast epithelial cell line MCF10A were also used in this study. qPCR was used to detect the expression of miR-28-3p in above mentioned tissues and cell lines. The correlation between miR-28-3p expression and clinical parameters was analyzed.After transfection with miR-28-3p inhibitor, the proliferation, apoptosis, invasion and migration ability of MDA-MB468 cells were detected with CCK-8, Flow cytometry, Transwell and Wound-healing experiment, respectively. And Western blotting was used to examine the protein expression of bridging integrator-1 (BIN1) in MDA-MB-468 cells. Bioinformatics BIN1 tool waere used to predict the target gene of miR-28-3p. Luciferase reporter gene assay was performed to validate the regulatory effect of miR-28-3p on BIN1. Results: The expression of miR-28-3p in TNBC tissues and cell lines was higher than that in matched paracancerous tissues and MCF10Acells (all P<0.01), respectively.Among the total 83 TNBC tissues, 56 (67.47%) showed high miR-28-3p expression. High expressionofmiR-28-3pwascloselycorrelated with the Ki-67 expression, tumor size and TNM stage (all P<0.05 or P<0.01). Compared with miR-NC group, transfection of miR-28-3p inhibitor significantly decreased the proliferation, invasion and migration of MDA-MB-468 cells while increased the apoptosis rate (all P<0.05 or P<0.01). Luciferase reporter gene assay confirmed that BIN1 was a target gene of miR-28-3p, and miR-28-3p inhibitor could up-regulate BIN1 expression in MDA-MB-468 cells (P<0.05). Conclusion: miR-28-3p is highly expressed in TNBC tissues and cell lines. miR-28-3p inhibitor up-regulates the expression of BIN1 to inhibit the proliferation, invasion and migration ability while promote the apoptosis of MDA-MB-468 cells.