Kras(G12D) induces EGFR-MYC cross signaling in murine primary pancreatic ductal epithelial cells

Oncogene. 2016 Jul 21;35(29):3880-6. doi: 10.1038/onc.2015.437. Epub 2015 Nov 23.

Abstract

Epidermal growth factor receptor (EGFR) signaling has a critical role in oncogenic Kras-driven pancreatic carcinogenesis. However, the downstream targets of this signaling network are largely unknown. We developed a novel model system utilizing murine primary pancreatic ductal epithelial cells (PDECs), genetically engineered to allow time-specific expression of oncogenic Kras(G12D) from the endogenous promoter. We show that primary PDECs are susceptible to Kras(G12D)-driven transformation and form pancreatic ductal adenocarcinomas in vivo after Cdkn2a inactivation. In addition, we demonstrate that activation of Kras(G12D) induces an EGFR signaling loop to drive proliferation. Interestingly, pharmacological inhibition of EGFR fails to decrease Kras(G12D)-activated ERK or PI3K signaling. Instead our data provide novel evidence that EGFR signaling is needed to activate the oncogenic and pro-proliferative transcription factor c-MYC. EGFR and c-MYC have been shown to be essential for pancreatic carcinogenesis. Importantly, our data link both pathways and thereby explain the crucial role of EGFR for Kras(G12D)-driven carcinogenesis in the pancreas.

MeSH terms

  • Animals
  • Carcinoma, Pancreatic Ductal / genetics
  • Carcinoma, Pancreatic Ductal / metabolism
  • Carcinoma, Pancreatic Ductal / pathology
  • Cell Line, Tumor
  • Cell Proliferation / genetics
  • Cell Transformation, Neoplastic / genetics
  • Cell Transformation, Neoplastic / metabolism
  • Cells, Cultured
  • Epithelial Cells / metabolism*
  • Epithelial Cells / transplantation
  • ErbB Receptors / genetics
  • ErbB Receptors / metabolism*
  • Gene Expression Profiling / methods
  • Immunoblotting
  • Mice, Inbred NOD
  • Mice, Knockout
  • Mice, SCID
  • Mice, Transgenic
  • Mutation
  • Pancreatic Ducts / cytology
  • Pancreatic Ducts / metabolism*
  • Pancreatic Neoplasms / genetics
  • Pancreatic Neoplasms / metabolism
  • Pancreatic Neoplasms / pathology
  • Proto-Oncogene Proteins c-myc / genetics
  • Proto-Oncogene Proteins c-myc / metabolism*
  • Proto-Oncogene Proteins p21(ras) / genetics
  • Proto-Oncogene Proteins p21(ras) / metabolism*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction / genetics

Substances

  • Myc protein, mouse
  • Proto-Oncogene Proteins c-myc
  • ErbB Receptors
  • Hras protein, mouse
  • Proto-Oncogene Proteins p21(ras)