Fig 1: Human liver fibroblasts release HGF to activate mitogenic MET signaling in PDAC cells.A. RNA was isolated and sequenced from primary fibroblast cultures that were established from a resected liver colorectal metastasis (Liver CAF), the paired nearby normal liver tissue (Liver Fibroblast), or a primary PDAC tumor specimen (PDAC CAF). B. Quantification of the fibroblast marker gene PDGFRA across fibroblast populations. C. Quantification of Liver CAF marker MASP1 and HGF gene expression across fibroblast populations. D. Quantification of HGF released by fibroblasts into conditioned media by ELISA. E. Western blot analysis of MET activation in human PDAC cell line PATC53 by a 3:1 ratio of conditioned media - fresh complete media from different fibroblast cultures as compared to HGF (1ng/mL) after 30 seconds. F. Western blot analysis of MET (30 seconds), STAT3, AKT, and ERK (15 minutes) in PATC53 PDAC cells treated with either HGF (1 ng/mL), the MET inhibitor cabozantinib (1μM) or combination. G. Western blot analysis of MET (30 seconds), STAT3, AKT and ERK (15 minutes) in PATC53 PDAC cells treated with either 3:1 liver fibroblast conditioned media:fresh media or fresh media alone or in combination with the MET inhibitor cabozantinib (1μM) or vehicle. H. Western blot analysis of MET, ERK, AKT, and STAT3 in sgMET vs. parental control PATC53 PDAC cells treated with a 3:1 ratio of liver fibroblast conditioned media:fresh media or fresh media. β-ACTIN was used as a loading control in all conditions. Error bars are mean ±SD; ** P ≤ 0.01; *** P ≤ 0.001; **** P ≤ 0.0001, by one-way Anova with Tukey post hoc.