Meprinα transactivates the epidermal growth factor receptor (EGFR) via ligand shedding, thereby enhancing colorectal cancer cell proliferation and migration

J Biol Chem. 2012 Oct 12;287(42):35201-35211. doi: 10.1074/jbc.M112.368910. Epub 2012 Aug 24.

Abstract

Meprinα, an astacin-type metalloprotease is overexpressed in colorectal cancer cells and is secreted in a non-polarized fashion, leading to the accumulation of meprinα in the tumor stroma. The transition from normal colonocytes to colorectal cancer correlates with increased meprinα activity at primary tumor sites. A role for meprinα in invasion and metastatic dissemination is supported by its pro-angiogenic and pro-migratory activity. In the present study, we provide evidence for a meprinα-mediated transactivation of the EGFR signaling pathway and suggest that this mechanism is involved in colorectal cancer progression. Using alkaline phosphatase-tagged EGFR ligands and an ELISA assay, we demonstrate that meprinα is capable of shedding epidermal growth factor (EGF) and transforming growth factor-α (TGFα) from the plasma membrane. Shedding was abrogated using actinonin, an inhibitor for meprinα. The physiological effects of meprinα-mediated shedding of EGF and TGFα were investigated with human colorectal adenocarcinoma cells (Caco-2). Proteolytically active meprinα leads to an increase in EGFR and ERK1/2 phosphorylation and subsequently enhances cell proliferation and migration. In conclusion, the implication of meprinα in the EGFR/MAPK signaling pathway indicates a role of meprinα in colorectal cancer progression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Caco-2 Cells
  • Cell Movement*
  • Cell Proliferation*
  • Colorectal Neoplasms / genetics
  • Colorectal Neoplasms / metabolism*
  • Colorectal Neoplasms / pathology
  • ErbB Receptors / genetics
  • ErbB Receptors / metabolism*
  • Humans
  • Hydroxamic Acids / pharmacology
  • Ligands
  • MAP Kinase Signaling System*
  • Metalloendopeptidases / genetics
  • Metalloendopeptidases / metabolism*
  • Mitogen-Activated Protein Kinase 1 / genetics
  • Mitogen-Activated Protein Kinase 1 / metabolism
  • Mitogen-Activated Protein Kinase 3 / genetics
  • Mitogen-Activated Protein Kinase 3 / metabolism
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism*
  • Phosphorylation / drug effects
  • Phosphorylation / genetics
  • Transforming Growth Factor alpha / genetics
  • Transforming Growth Factor alpha / metabolism

Substances

  • Anti-Bacterial Agents
  • Hydroxamic Acids
  • Ligands
  • Neoplasm Proteins
  • Transforming Growth Factor alpha
  • EGFR protein, human
  • ErbB Receptors
  • MAPK1 protein, human
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3
  • Metalloendopeptidases
  • meprin A
  • actinonin