ABSTRACT
Abstract Background MicroRNAs (miRNAs) are involved in the progression of diverse human cancers. This work aimed to delve into how microRNA-135a-5p (miR-135a-5p) affects the biological behaviors of Breast Cancer (BC) cells. Methods Gene Expression Omnibus (GEO) datasets were used to analyze the expression differences of miR-135a-5p in cancer tissues of BC patients. Quantitative real-time PCR and western blot were conducted to detect miR-135a-5p and Bcl-2 Associated Athanogene (BAG3) expression levels in BC tissues and cells, respectively. The proliferation, migration, invasion, and cell cycle of BC cells were detected by cell counting kit-8 assay, BrdU assay, wound healing assay, transwell assay, and flow cytometry. The targeted relationship between miR-135a-5p and BAG3 mRNA 3′UTR predicted by bioinformatics was further testified by a dual-luciferase reporter gene assay. Pearson's correlation analysis was adopted to analyze the correlation between miR-135a-5p expression and BAG3 expression. The downstream pathways of BAG3 were analyzed by the LinkedOmics database. Results MiR-135a-5p was significantly down-regulated and BAG3 expression was significantly raised in BC tissues. MiR-135a-5p overexpression repressed the viability, migration and invasion of BC cells, and blocked cell cycle progression in G0/G1 phase while inhibiting miR-135a-5p worked oppositely. BAG3 was verified as a target of miR-135a-5p. Overexpression of BAG3 reversed the impacts of miR-135a-5p on the malignant biological behaviors of BC cells. The high expression of BAG3 was associated with the activation of the cell cycle, mTOR and TGF-β signaling pathways. Conclusion MiR-135a-5p regulates BAG3 to repress the growth, migration, invasion, and cell cycle progression of BC cells.
ABSTRACT
@# Objective: To explore the molecular mechanism of miR-130a-3p regulating epithelial mesenchymal transition (EMT) to affect the invasion and metastasis of breast cancer cells through HGF/MET pathway. Methods: A total of 22 pairs of cancer tissues and adjacent normal tissues from breast cancer patients, who were admitted to Affiliated Hospital of Chengde Medical College from January 2018 to October 2018, were collected for this study; in addition, breast cancer cell lines (MCF-7, MDA-MB-231 and MDA-MB453) and normal breast epithelial cells MCF10A were obtained from the Institute of Basic Sciences, Chengde Medical College. And then, the expression of miR-130a-3p in tissues and cell lines were detected by qRT-PCR. The experiment cells were divided into control group, miR-130a-3p mimics group, miR-130a-3p inhibitor group, PHA665752 (a small-molecule MET inhibitor) transfection group and PHA665752+miR-130a-3p inhibitor co-transfection group. CCK-8 assay and Transwell assay were performed to detect the proliferation, invasion and migration of MCF-7 cells, respectively. The expressions of EMT and HGF/MET signaling pathway related proteins in MCF-7 cells were detected by WB. In addition, the targeted relationship between miR-130a-3p and MET was verified by Dual luciferase reporter gene assay. Results: miR-130a-3p was down-regulated in breast cancer tissues and cell lines. Over-expression of miR130a-3p could suppress the proliferation, invasion, migration and EMT of MCF-7 cells, while knockdown of miR-130a-3p had the opposite results. The results of Dual luciferase reporter gene assay indicated that miR-130a-3p targetedly down-regulated the expression of MET, and miR-130a-3p negatively regulated the expression of HGF/MET signaling pathway. Further experiments confirmed that miR-130a-3p inhibited the proliferation, invasion, migration and EMT of MCF-7 cells by blocking HGF/MET signaling pathway. Conclusion: miR-130a-3p suppresses the EMT of MCF-7 cells via blocking HGF/MET signaling pathway, thereby repressing the invasion and metastasis of MCF-7 cells.