From functional genomics to precision medicine: The therapeutic potential of targeting ROCK signaling in pancreatic cancer.

Abstract

e15029 Background: Pancreatic cancer (PC) is a highly lethal disease with few effective treatment options for metastatic disease. PC is a genetically highly heterogeneous disease that lends itself to a personalised approach to translational research (Biankin et al. Nature. 2012 Nov 15;491(7424):399-405.). Genomic sequence data from the Australian Pancreatic Genome Initiative (APGI) has identified a subset of patients with ROCK-1 amplification. ROCK-1 is a downstream target of Rho, a small GTPase, which is involved in cell adhesion and motility and has been shown to play a role in cancer cell growth and invasiveness (S. Boeck, P. Stieber, et al. Oncology 2006; 70:255., Lane J, Martin T et al. Int J Onc 2008; 33:585-593.). Our aim is to identify biologically and clinically relevant, targetable phenotypes for PC by examining therapeutic efficacy of two ROCK-1 inhibitors, Y-27632 and fasudil in model systems with aberrant Rho/ROCK signaling. Methods: Using extensively characterised model systems of PC, including unique primary patient derived xenografts (PDX) and patient derived cell lines (PDCL) established in the laboratory, we are examining the efficacy of individualized rationally designed combination therapies based on targeting Rho/ROCK signaling. Using innovative techniques, including organotypic assays, we are examining the effect of the targeted approach on cell proliferation, migration, invasion and metastasis in relevant models of PC. Results: Here we demonstrate significant differential sensitivity of pancreatic PDXs and PDCLs with aberrant Rho/ROCK signaling to ROCK combination therapy when compared with standard therapy, gemcitabine. Finally, these compounds impair invasiveness of human pancreatic tumour cells, suggesting that ROCK-1 is a targetable phenotype for the treatment of PC. Conclusions: By carefully defining the key cancer subtypes and expanding our knowledge about the interplay of the key regulators and activators of the Rho/ROCK pathway, the promise of ROCK inhibitors for PC therapy may be realized. As fasudil is already in clinical use for the treatment of cerebral vasospasm, this work may be quickly translated to the clinic.