The primary goal of this research is to investigate how genetic aberrations in pancreatic epithelial cells alter epithelial-stromal signaling during the development of pancreatic ductal adenocarcinoma (PDAC). Genetically defined mouse pancreatic epithelial cells representing different stages of PDAC development will be combined with stromal mouse pancreatic stellate cells. The proteome of each cell type will be labelled using SILAC. These labelled cells will be subjected to combinations of mono and co-culture experiments to simulate autocrine and paracrine cell signaling scenarios respectively. Total protein levels and changes in protein phosphorylation will be investigated by high-resolution quantitative mass-spectrometry. As individual cells will be SILAC labelled before each experiment, the cell-origin for each protein can be deduced during analysis. Time-course communication experiments will be performed to monitor the cell-specific chronology of signaling events. In collaboration with Prof. Doug Lauffenburger (MIT), this cell-specific chronological proteomic data will be used to develop data-driven hypotheses of reciprocal cell signaling across each defined genetic background. These hypotheses will then be tested against tissue from genetically engineered mouse models of PDAC to assess the prevalence of these signaling events in vivo.