ROCK, or Rho-associated coiled coil-containing
protein kinase, is a member of the AGC
kinase family and has been shown to play a role in cell migration, ECM synthesis, stress-fiber assembly, and cell contraction. Increased ROCK expression has been reported in multiple pathological conditions, including
cancer. Here, we report increased expression of ROCK 1 in pancreatic
tumor epithelial cells as well as in cancer associated fibroblasts (CAF). In our analysis, 62% of
tumor samples exhibited ≥2+ in staining intensity by IHC analysis, versus 40% of adjacent normal tissue samples (P<0.0001). Thus, we hypothesized that ROCKs may play a significant role in
pancreatic cancer progression, and may serve as a suitable target for treatment. We report a low frequency (4/34) amplification of the ROCK1 gene locus at chromosome 18q11.1 in pancreatic ductal
adenocarcinoma (PDAC) patient tissue samples by aCGH analysis. Inhibition of ROCK
kinase activity by a small molecule inhibitor (
fasudil) resulted in moderate (IC50s of 6-71 μM) inhibition of PDAC cell proliferation, migration, and activation of co-cultured stellate cells. In the KPC mouse model for
pancreatic cancer,
fasudil decreased
tumor collagen deposition. This translated to an enhanced overall survival of the mice and an increase in
gemcitabine uptake. Though
fasudil may target both the
tumor epithelial cells and the CAFs, our findings are consistent with the hypothesis that inhibition of
tumor stroma enhances drug penetration and efficacy in PDAC. Overall, our data suggests that ROCK1 may serve as a potential therapeutic target to enhance current treatment regimens for
pancreatic cancer.