Activation of c-Met in colorectal carcinoma cells leads to constitutive association of tyrosine-phosphorylated beta-catenin

Clin Exp Metastasis. 2003;20(4):291-300. doi: 10.1023/a:1024024218529.

Abstract

Increased expression and/or activity of c-Met, the receptor protein tyrosine kinase for hepatocyte growth factor/scatter factor, occurs commonly during colon tumor progression. To examine potential roles for c-Met in promoting metastasis, we compared the colon tumor cell line KM12C with low metastatic potential to the isogenic variants KM,12L4 and KM12SM with high metastatic potential. KM12C cells express c-Met with low levels of tyrosine phosphorylation in the absence of HGF. The high metastatic cells express a c-Met that is constitutively tyrosine phosphorylated, they have increased colony formation, and are minimally responsive to HGF relative to the parental cells. Tyrosine-phosphorylated beta-catenin was constitutively associated with c-Met in the more metastatic cells, but was inducible only after HGF addition in the less metastatic cells. Functions mediated by beta-catenin, including cell-cell adhesion and migration, and activation of the tcf (T-cell factor) family of transcription factors, were also elevated in the more metastatic KM12SM and L4 cells. Furthermore, analysis of the known tcf transcriptional target genes, cyclin D1, c-Myc, and uPAR, demonstrated increased expression in the high metastatic cells, correlating with the levels of tcf activity. Collectively, these results suggest that endogenous activation of c-Met in highly metastatic KM12SM CRC cells results in increased survival and growth under anchorage independent conditions, increased in vitro migration, and elevated levels of tcf target genes. Thus, beta-catenin association with activated c-Met may contribute to a more aggressive liver metastatic phenotype of these cells.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Blotting, Western
  • Cell Adhesion
  • Cell Movement
  • Colony-Forming Units Assay
  • Colorectal Neoplasms / genetics
  • Colorectal Neoplasms / metabolism*
  • Colorectal Neoplasms / pathology
  • Cyclin D1 / metabolism
  • Cytoskeletal Proteins / metabolism*
  • Gene Expression Regulation, Neoplastic
  • Hepatocyte Growth Factor / genetics
  • Hepatocyte Growth Factor / metabolism
  • Humans
  • Luciferases / metabolism
  • Mitogen-Activated Protein Kinase 1 / metabolism
  • Mitogen-Activated Protein Kinase 3
  • Mitogen-Activated Protein Kinases / metabolism
  • Mutation
  • Phosphorylation
  • Promoter Regions, Genetic
  • Proto-Oncogene Proteins c-met / metabolism*
  • Trans-Activators / metabolism*
  • Transcriptional Activation
  • Tumor Cells, Cultured
  • Tyrosine / metabolism*
  • beta Catenin

Substances

  • CTNNB1 protein, human
  • Cytoskeletal Proteins
  • Trans-Activators
  • beta Catenin
  • Cyclin D1
  • Tyrosine
  • Hepatocyte Growth Factor
  • Luciferases
  • Proto-Oncogene Proteins c-met
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3
  • Mitogen-Activated Protein Kinases