Identification of a pivotal endocytosis motif in c-Met and selective modulation of HGF-dependent aggressiveness of cancer using the 16-mer endocytic peptide

Oncogene. 2013 Feb 21;32(8):1018-29. doi: 10.1038/onc.2012.122. Epub 2012 Apr 23.

Abstract

Since c-Met has an important role in the development of cancer, it is considered as an attractive target for cancer therapy. Although molecular mechanisms for oncogenic property of c-Met have been actively investigated, regulatory elements for c-Met endocytosis and its effect on c-Met signaling remain unclear. In this study, we identified a pivotal endocytic motif in c-Met and tested it for selective modulation of HGF-induced c-Met response. Using various chimeric constructs with the cytoplasmic tail of c-Met, we were able to demonstrate that a dileucine motif located in the C-terminus of c-Met acts to regulate its endocytosis. Synthetic peptide Ant-3S, consisting of antennapedia-derived protein transduction domain (designated as Ant) and c-Met-derived 16 amino-acids (designated as 3S, spanning amino-acids 1378 to 1393), rapidly moved into cancer cells and disrupted c-Met trafficking. Importantly, an extension of c-Met retention time on the membrane by Ant-3S peptide significantly decreased phosphorylation-dependent c-Met signal transduction. Additionally, the peptide effectively inhibited HGF-induced cell growth, scattering and migration. The underlying molecular mechanism for these observations has been investigated and revealed that the dileucine motif interacts with endocytic machinery, including adaptin β and caveolin-1, for sustained and enhanced signal transduction. Finally, Ant-3S peptide specifically blocked internalization of interleukin-2 receptor α-subunit/3S chimeric protein, but not the other receptors, including Glut4, Glut8 and transferrin receptor. Such results indicate the presence of a selective endocytic assembly for c-Met. It also suggests a potential for c-Met-specific anti-cancer therapy using the identified endocytic motif in this study.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Motifs
  • Animals
  • Cell Line, Tumor
  • Endocytosis / drug effects
  • Hepatocyte Growth Factor / metabolism*
  • Humans
  • Mice
  • Neoplasms / drug therapy
  • Neoplasms / genetics
  • Neoplasms / metabolism*
  • Neoplasms / pathology*
  • Peptides / pharmacology*
  • Proto-Oncogene Proteins c-met / metabolism*
  • Signal Transduction / drug effects

Substances

  • Peptides
  • Hepatocyte Growth Factor
  • Proto-Oncogene Proteins c-met