Down-regulating Ribonuclease Inhibitor Enhances Metastasis In Bladder Cancer Cells Via Activating Epithelial-mesenchymal Transition And ILK Signaling Pathway

Purpose: Accumulating evidences implicate that Ribonucleaseinhibitor (RI) play a suppressing role in cancer development. However, themechanisms underlying antitumor of RI remain largely unknown. Thepurpose of the current study is to investigate the effects of down-regulatingRI on metastasis via Epithelial-to-Mesenchymal Transition and ILKsignaling pathway in bladder cancers.Methods: Bladder cancer T24cells were transfected with pGensil-1-siRNA-RI vectors. HE staining, living cells observation, Phalloidine-FITCstaining of microfilament, cell adhesion, scratch migration, and matrigelinvasion were examined respectively. RI expression and colocalization withILK was detected using confocal microscope. Proteins associated with EMTwere determined with Western blotting and immunohistochemistry in vivoand in vitro. Effects of RI expression on tumor growth，metastasis and EMT related proteins in BALB/C nude mouse and clinical human bladder cancerspecimens were valued with histological, immunohistochemical andimmunofluorescent examination respectively.Results: We demonstrated that down-regulating RI increased cellproliferation, migration and invasion, changed cell morphology, adhesionand rearranged cytoskeleton by inducing EMT and ILK signaling pathwayin bladder cancer cells. In addition, we found that bladder cancer withinvasive capability had higher Vimentin, Snail, Slug and Twist as well aslower E-cadherin and RI expression in clinical human specimens. Finally,we showed that down-regulating RI promoted tumorigenesis and metastasisof bladder cancer in vivo.Conclusions: Our results suggested that RI could be a promising targetfor bladder cancer therapy.