Abstract 2623: Snail 1 regulates invasion through uPA-uPAR signaling using the MAPK pathway in prostate cancer cells.

Abstract

Abstract Epithelial-mesenchymal transition (EMT) is a process by which cancer cells acquire mesenchymal properties, such as induction of N-cadherin, while epithelial-associated genes like E-cadherin are lost. This enables the cells to be more invasive, migratory and metastatic. Factors that can induce EMT include growth factors like transforming growth factor -β (TGF-β) and epidermal growth factor (EGF), and transcription factors like Snail1. Snail1-induced EMT promotes migration and invasion and we hypothesized that this may be mediated by urokinase (uPA) and its receptor (uPAR) activities. uPA, a serine protease, may be activated by integrin engagement to bind to its receptor, uPAR, and initiate a signaling cascade that regulates a variety of biological pathways including invasion. Androgen-dependent LNCaP and 22Rv1 and androgen-independent ARCaP human prostate cancer (PC) cells were stably transfected with empty vector control (Neo) or constitutively active Snail1 which led to increased cell migration and invasion. Superarray analysis revealed an upregulation in uPAR expression in Snail-transfected cells as compared to Neo control. Next, the protein expression levels of Snail1, uPA, and uPAR were measured by Western Blot analysis. uPA activity in conditioned media was measured using the Elisa uPA activity assay kit. Also, uPAR was transiently silenced in ARCaP Snail-overexpressing cells using uPAR siRNA. Additionally, cells were treated with MAPK inhibitor, UO126, at set time points. The data suggests that overexpression of Snail1 increased uPA and uPAR protein levels, and uPA activity was elevated in conditioned media from LNCaP, 22Rv1 and ARCaP Snail-overexpressing cells, as compared to Neo controls. Additionally, the silencing of uPAR decreased cell invasion in ARCaP Snail-overexpressing cells. Finally, MAPK inhibitor, UO126, inhibited cell invasion and decreased uPA activity. Therefore, Snail-mediated cell invasion in human prostate cancer cells may occur via the regulation of the MAPK and uPA/ uPAR signaling pathway. Acknowledgements: These studies were supported by the: NIH/NCRR/RCMI grant G12RR03062 and NIH P20 grant 1P20MD002285. Citation Format: Diandra D. Randle, Valerie Marah. Snail 1 regulates invasion through uPA-uPAR signaling using the MAPK pathway in prostate cancer cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2623. doi:10.1158/1538-7445.AM2013-2623