miR-148a is an androgen-responsive microRNA that promotes LNCaP prostate cell growth by repressing its target CAND1 expression.

Recent advances in cancer biology reveal that microRNAs (miRNAs) are involved in the regulation of cancer-related genes, or they function as tumor suppressors or oncogenes. In prostate cancer, evidence has accumulated for the contribution of the androgen-dependent gene network to tumor growth, although the precise functions of miRNAs in prostate cancer remain to be investigated. Here, we identified androgen-responsive miRNAs by the short RNA sequencing analysis in LNCaP prostate cancer cells. Among 10 miRNAs with known sequences, we have determined that miR-148a reduces the expression of cullin-associated and neddylation-dissociated 1 (CAND1), a negative regulator of SKP1-Cullin1-F-box (SCF) ubiquitin ligases, by binding to the 3'-untranslated region of CAND1 mRNA. CAND1 knockdown by small interfering RNA promoted the proliferation of LNCaP cells. Our study indicates the potential contribution of miR-148a to the growth of human prostate cancer.