B3GNT2, a polylactosamine synthase, regulates glycosylation of EGFR in H7721 human hepatocellular carcinoma cells

Asian Pac J Cancer Prev. 2014;15(24):10875-8. doi: 10.7314/apjcp.2014.15.24.10875.

Abstract

The epidermal growth factor receptor (EGFR) is an important surface receptor with N-glycans in its extracellular domain, whose glycosylation is essential for its function, especially in tumor cells. Here, we demonstrated that polylactosamine is markedly increased in H7721 hepatocellular carcinoma cells after treatment with EGF, while it apparently declined after exposure to all-trans retinoic acid (ATRA). In the study of the enzymatic mechanism of this phenomenon, we explored changes in the expression of poly-N-acetyllactosamine (PLN) branching glycosyltransferases using RT-PCR. Among the four glycosyltransferases with altered expression, GnT-V was most elevated by EGF, while GnT-V and B3GNT2 were most declined by ATRA. Next, we conducted co-immunoprecipitation experiments to test whether B3GNT2 and EGFR associate with each other. We observed that EGFR is a B3GNT2-targeting protein in H7721 cells. Taken together, these findings indicated that the altered expression of B3GNT2 will remodel the PLN stucture of EGFR in H7721 cells, which may modify downstream signal transduction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / pharmacology
  • Blotting, Western
  • Carcinoma, Hepatocellular / drug therapy
  • Carcinoma, Hepatocellular / metabolism*
  • Carcinoma, Hepatocellular / pathology
  • Epidermal Growth Factor / pharmacology
  • ErbB Receptors / genetics
  • ErbB Receptors / metabolism*
  • Fluorescent Antibody Technique
  • Glycosylation
  • Humans
  • Immunoprecipitation
  • Liver Neoplasms / drug therapy
  • Liver Neoplasms / metabolism*
  • Liver Neoplasms / pathology
  • N-Acetylglucosaminyltransferases / genetics
  • N-Acetylglucosaminyltransferases / metabolism*
  • Phosphorylation / drug effects
  • Polysaccharides / metabolism*
  • RNA, Messenger / genetics
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction
  • Tretinoin / pharmacology
  • Tumor Cells, Cultured

Substances

  • Antineoplastic Agents
  • Polysaccharides
  • RNA, Messenger
  • Tretinoin
  • Epidermal Growth Factor
  • poly-N-acetyllactosamine
  • N-Acetylglucosaminyltransferases
  • B3GNT2 protein, human
  • EGFR protein, human
  • ErbB Receptors