AIM:To investigate the expression of up-regulated gene 11 ( URG11 ) in prostate cancer cell line and the effect of URG11 siNRA on the proliferation and invasion of human prostate cancer LNCaP cells.METHODS:The mRNA and protein levels of URG11 in prostate cancer cell lines and normal prostate epithelial cell line were evaluated by real-time PCR and Western blot.LNCaP cells were transfected with designed siRNA using the liposome method.The prolif-eration, apoptosis, migration and invasion abilities of the LNCaP cells were evaluated by MTS assay, flow cytometry, wound-healing assay and Transwell assay.RESULTS:The expression of URG11 at mRNA and protein levels in the DU145, PC3, LNCaP cell lines was significantly higher than that in RWPE-1 cell line.Compared with the control group, the proliferation of LNCaP cells with URG11 siRNA was stagnant in G1/S phase and induced apoptosis.The proliferation of LNCaP cells at 0 h, 24 h, 48 h and 72 h was inhibited after URG11 expression was down-regulated (P<0.05).Transwell assay showed that migration (P<0.05) and invasion (P<0.05) were also inhibited.CONCLUSION:URG11 is highly expressed in prostate cancer.Silencing of URG11 significantly inhibits the proliferation and invasion and induces apoptosis of LNCaP cells.