Dysregulation of microRNA (miRNA) expression is associated with hallmarks of aggressive tumor phenotypes, e.g., enhanced cell growth, proliferation, invasion, and anchorage independent growth in prostate cancer (PCa).
Serum-based miRNA profiling involved 15 men diagnosed with non-metastatic (stage I, III) and metastatic (stage IV) PCa and five age-matched disease-free men using miRNA arrays with select targets confirmed by quantitative real-time PCR (qRT-PCR). The effect of miR-186-5p inhibition or ectopic expression on cellular behavior of PCa cells (i.e., PC-3, MDA-PCa-2b, and LNCaP) involved the use bromodeoxyuridine (BrdU) incorporation, invasion, and colony formation assays. Assessment of the impact of miR-186-5p inhibition or overexpression on selected targets entailed microarray analysis, qRT-PCR, and/or western blots. Statistical evaluation used the modified t-test and ANOVA analysis.
MiR-186-5p was upregulated in serum from PCa patients and metastatic PCa cell lines (i.e., PC-3, MDA-PCa-2b, LNCaP) compared to serum from disease-free individuals or a normal prostate epithelial cell line (RWPE1), respectively. Inhibition of miR-186-5p reduced cell proliferation, invasion, and anchorage-independent growth of PC-3 and/or MDA-PCa-2b PCa cells. AKAP12, a tumor suppressor target of miR-186-5p, was upregulated in PC-3 and MDA-PCa-2b cells transfected with a miR-186-5p inhibitor. Conversely, ectopic miR-186-5p expression in HEK 293 T cells decreased AKAP12 expression by 30%. Both pAKT and β-catenin levels were down-regulated in miR-186-5p inhibited PCa cells.
Our findings suggest miR-186-5p plays an oncogenic role in PCa. Inhibition of miR-186-5p reduced PCa cell proliferation and invasion as well as increased AKAP12 expression. Future studies should explore whether miR-186-5p may serve as a candidate prognostic indicator and a therapeutic target for the treatment of aggressive prostate cancer.
BMC cancer. 2018 Apr 13*** epublish ***
Dominique Z Jones, M Lee Schmidt, Suman Suman, Katharine R Hobbing, Shirish S Barve, Leila Gobejishvili, Guy Brock, Carolyn M Klinge, Shesh N Rai, Jong Park, Geoffrey J Clark, Rajesh Agarwal, LaCreis R Kidd
Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, 40292, USA., Department of Biomedical Informatics, The Ohio State University, Columbus, USA., James Graham Brown Cancer Center, University of Louisville School of Medicine, Louisville, USA., Department of Cancer Epidemiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, USA., Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Denver, USA., Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, 40292, USA. .