Journal Article

PC-3M-luc-C6, PC-3M-luc, IVIS, Bioware, Prostate cancer, Bioluminescence, Animals; Base Sequence; Blotting, Western; Chromatin Immunoprecipitation; Clusterin/genetics/*physiology; DNA Primers; Epithelial-Mesenchymal Transition/*physiology; Humans; Male; Mice; *Neoplasm Metastasis; Nuclear Proteins/*physiology; Promoter Regions, Genetic; Prostatic Neoplasms/*pathology; Reverse Transcriptase Polymerase Chain Reaction; Transforming Growth Factor beta/*physiology; Twist Transcription Factor/*physiology

TGF-beta promotes epithelial-mesenchymal transition (EMT) and induces clusterin (CLU) expression, linking these genes to cancer metastasis. CLU is a pleiotropic molecular chaperone that confers survival and proliferative advantage to cancer cells. However, the molecular mechanisms by which TGF-beta regulates CLU expression and CLU affects metastasis remain unknown. In this study, we report that the transcription factor Twist1 mediates TGF-beta-induced CLU expression. By binding to E-boxes in the distal promoter region of CLU gene, Twist1 regulated basal and TGF-beta-induced CLU transcription. In addition, CLU reduction reduced TGF-beta induction of the mesenchymal markers, N-cadherin and fibronectin, thereby inhibiting the migratory and invasive properties induced by TGF-beta. Targeted inhibition of CLU also suppressed metastasis in an in vivo model. Taken together, our findings indicate that CLU is an important mediator of TGF-beta-induced EMT, and suggest that CLU suppression may represent a promising therapeutic option for suppressing prostate cancer metastatic progression.