It is increasingly clear that microRNAs (miRNAs) play an important role in many diseases, including tumorigenesis. However, the mechanisms by which miRNAs regulated bladder cancer development remain poorly understood. Here we evaluated the expression of miR-203 in bladder cancer tissues by real-time polymerase chain reaction, and defined the target genes and biologically functional effect by luciferase reporter assay, flow cytometry and western blot analysis. We firstly verified that the expression of miR-203 was decreased in bladder cancer tissues. Moreover, ectopic expression of miR-203 promoted the apoptosis of human bladder cancer cell lines and inhibited cell proliferation, whereas its depletion increased cell growth. We further verified that miR-203 directly targeted 3'-untranslated region of bcl-w gene, and decreased its expression in vitro and in vivo. Western blot analysis also showed that the expression level of miR-203 was negatively correlated with bcl-w level in tumor tissues. These data suggest an important role of miR-203 in the molecular etiology of bladder cancer and implicate the potential application of miR-203 in bladder cancer therapy.

Journal compilation © 2010 Federation of European Biochemical Societies.

PMID: 21205209 [PubMed - as supplied by publisher] Source: National Library of Medicine.