Inhibition of cancer cell-derived exosomal microRNA-183 suppresses cell growth and metastasis in prostate cancer by upregulating TPM1

BACKGROUND: Emerging evidence continues to highlight the significant role of microRNAs (miRNAs) in the regulation of cancer growth and metastasis. Herein, the current study aimed to elucidate the role of exosomal miR-183 in prostate cancer development. METHODS: Initially, public microarray-based gene expression profiling of prostate cancer was employed to identify differentially expressed miRNAs. The putative target gene TPM1 of miR-183 was subsequently predicted, followed by the application of a luciferase reporter assay and examination of the expression patterns in prostate cancer patients and cell lines. The effects of miR-183 and TPM1 on processes such as cell proliferation, invasion and migration were evaluated using in vitro gain- and loss-of-function experiments. The effect of PC3 cells-derived exosomal miR-183 was validated in LNCaP cells. In vivo experiments were also performed to examine the effect of miR-183 on prostate tumor growth. RESULTS: High expression of miR-183 accompanied with low expression of TPM1 was detected in prostate cancer. Our data indicated that miR-183 could target and downregulate TPM1, with the overexpression of miR-183 and exosomal miR-183 found to promote cell proliferation, migration, and invasion in prostate cancer. Furthermore, the tumor-promoting effect of exosome-mediated delivery of miR-183 was subsequently confirmed in a tumor xenograft model. CONCLUSIONS: Taken together, the key findings of our study demonstrate that prostate cancer cell-derived exosomal miR-183 enhance prostate cancer cell proliferation, invasion and migration via the downregulation of TPM1, highlighting a promising therapeutic target against prostate cancer.