N-Cadherin and Keratinocyte Growth Factor Receptor Mediate the Functional Interplay between Ki-RAS^G12V and p53^V143A in Promoting Pancreatic Cell Migration, Invasion, and Tissue Architecture Disruption

Abstract

The genetic basis of pancreatic ductal adenocarcinoma, which constitutes the most common type of pancreatic malignancy, involves the sequential activation of oncogenes and inactivation of tumor suppressor genes. Among the pivotal genetic alterations are Ki-RAS oncogene activation and p53 tumor suppressor gene inactivation. We explain that the combination of these genetic events facilitates pancreatic carcinogenesis as revealed in novel three-dimensional cell (spheroid cyst) culture and in vivo subcutaneous and orthotopic xenotransplantation models. N-cadherin, a member of the classic cadherins important in the regulation of cell-cell adhesion, is induced in the presence of Ki-RAS mutation but subsequently downregulated with the acquisition of p53 mutation as revealed by gene microarrays and corroborated by reverse transcription-PCR and Western blotting. N-cadherin modulates the capacity of pancreatic ductal cells to migrate and invade, in part via complex formation with keratinocyte growth factor receptor and neural cell adhesion molecule and in part via interaction with p120-catenin. However, modulation of these complexes by Ki-RAS and p53 leads to enhanced cell migration and invasion. This preferentially induces the downstream effector AKT over mitogen-activated protein kinase to execute changes in cellular behavior. Thus, we are able to define molecules that in part are directly affected by Ki-RAS and p53 during pancreatic ductal carcinogenesis, and this provides a platform for potential new molecularly based therapeutic interventions.

This work was supported by NIH/NIDDK grant R01 DK50306 (A.K.R., T.B.D., M.T., M.J.B., and B.R.), the National Pancreas Foundation (T.B.D.), NIH grants RO1-EB001872 and R24-CA92782 (U.M., R.U., and R.W.), the NIH/NIDDK Center for Molecular Studies in Digestive and Liver Diseases (Morphology, Molecular Biology, Mouse, and Cell Culture Cores) grant P30 DK50306, and the Bioluminescence Molecular Imaging Core facility at the University of Pennsylvania (supported in part by NIH grant CA105008).

We thank Gary Swain, Kelly Dempsey, and Shukriyyah Mitchell for technical assistance, Eric Bernhard for assistance with radiation experiments, Russ Carstens and Wafik El-Deiry for reagents, and members of the Rustgi laboratory (Hiroshi Nakagawa, Hideki Harada, Claudia Andl, and Takaomi Okawa) for discussion.