LncRNA UCA1 acts as a sponge of miR-204 to up-regulate CXCR4 expression and promote prostate cancer progression

Prostate cancer (PCa) is a devastating malignant disease with a poor prognosis. The aim of current study is to investigate the role of lncRNA-urothelial carcinoma associated 1 (UCA1) in the progression of PCa. We evaluated the expression levels of UCA1 in a total of 16 benign prostatic hyperplasia tissues (BPH) and 40 PCa tissues, as well as PCa cells. The functional regulatory effects of UCA1 were investigated using a series of cell function approaches. Our data showed that UCA1 is frequently overexpressed in PCa tissues compared with BPH tissues (P<0.01). Moreover, the higher expression of UCA1 was observed in patients with Gleason score >= 8 (P<0.05). In consistent, we found the expression levels of UCA1 was higher in the PCa cell lines PC-3, LnCaP, and DU-145 than in the normal prostate epithelial cell line RWPE-1 (P<0.01). Functionally, we found knockdown of UCA1 in PC-3 significantly suppressed cell growth and invasion of PC-3, while overexpression of UCA1 in DU-145 cells promote cell growth and invasion. Mechanistically, UCA1 overexpression permitted activation of CXCR4 oncogenes through inhibition of miR-204 activity, as evidenced by the positive association of these two genes with UCA1 levels and inverse correlation with miR-204 expression in PCa tissues. Luciferase activity assay further confirmed the targetting relationship between UCA1 and miR-204, CXCR4, and miR-204. The up-regulation of UCA1 in PC-3 cells significantly impaired the inhibitory effect of miR-204 on CXCR4 expression. Taken together, our research revealed that UCA1 works as an oncogene by targetting miR-204. The UCA1-miR-204-CXCR4 regulatory network regulated the growth and metastasis of PCa, providing new insight in the management of patients with such malignancy.