The effect of receptor protein tyrosine phosphatase kappa on the change of cell adhesion and proliferation induced by N-acetylglucosaminyltransferase V

J Cell Biochem. 2010 Jan 1;109(1):113-23. doi: 10.1002/jcb.22387.

Abstract

N-acetylglucosaminyltransferase V (GnT-V) has been reported to be positively associated with tumor progression, but its mechanism still remains unknown. In the present study, we found that GnT-V overexpression not only changed the glycosylation of receptor protein tyrosine phosphatase kappa (RPTPkappa) but also decreased its protein level. Moreover, GnT-V overexpression decreased cell calcium-independent adhesion and increased the tyrosine phosphorylation level of beta-catenin, in which RPTPkappa played an important role. Since RPTPkappa has an RXKR motif, which is a favored cleavage site for furin, we used furin inhibitor to further explore the effect of RPTPkappa on the change of cell adhesion and beta-catenin signaling induced by GnT-V. Our results showed that preventing RPTPkappa cleavage rescued the above effects of GnT-V, suggesting that furin cleavage could be one of the factors for RPTPkappa to regulate cell adhesion and beta-catenin signaling in GnT-V overexpression cell lines. In addition, the increased tyrosine phosphorylation level of beta-catenin was associated with the increased nuclear level of beta-catenin and downstream signaling molecules such as c-myc and cyclin D1 that were associated with cell proliferation. Our results suggest that GnT-V could decrease human hepatoma SMMC-7721 cell adhesion and promote cell proliferation partially through RPTPkappa.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Western
  • Cell Adhesion / physiology
  • Cell Line, Tumor
  • Cell Proliferation*
  • Fluorescent Antibody Technique
  • Humans
  • Immunoprecipitation
  • N-Acetylglucosaminyltransferases / metabolism*
  • RNA Interference
  • Receptor-Like Protein Tyrosine Phosphatases, Class 2 / metabolism*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction / physiology*
  • beta Catenin / metabolism

Substances

  • beta Catenin
  • N-Acetylglucosaminyltransferases
  • alpha-1,6-mannosylglycoprotein beta 1,6-N-acetylglucosaminyltransferase
  • PTPRK protein, human
  • Receptor-Like Protein Tyrosine Phosphatases, Class 2