Rho-associated protein kinase (ROCK) inhibitors inhibit survivin expression and sensitize pancreatic cancer stem cells to gemcitabine

Abstract

Background: Targeting pathways regulating survivin expression, which has been implicated in multidrug resistance of cancer cells, is a promising strategy to overcome cancer chemoresistance. To date, the role of rhoassociated protein kinases (ROCKs) in survivin expression remains largely unknown. Materials and Methods: The effects of ROCK inhibitors Y-27632 and fasudil on survivin expression and cell viability were determined by immunoblot analysis and dye exclusion, respectively, in PANC-1 CSLC, a cancer stem cell line derived from a serum-cultured, gemcitabine-sensitive pancreatic cancer cell line, PANC-1. Results: siRNA-mediated knockdown of survivin revealed that the gemcitabine resistance of PANC-1 CSLC was dependent on survivin expression. Both Y-27632 and fasudil, reduced survivin expression in PANC-1 CSLC cells and sensitized them to gemcitabine. ROCK inhibition also reduced survivin expression in various other human cancer cell lines. Conclusion: Small molecule inhibitor-mediated targeting of ROCK may be a viable strategy to overcome cancer chemoresistance through down-regulation of survivin.