Selection of monoclonal antibodies which induce internalization and phosphorylation of p185HER2 and growth inhibition of cells with HER2/NEU gene amplification

Int J Cancer. 1991 Apr 1;47(6):933-7. doi: 10.1002/ijc.2910470625.


In order to obtain further information on the biological role of the HER2/neu oncoprotein monoclonal antibodies (MAbs) were produced against the p185 extracellular domain. To immunize the mice and screen the hybridoma supernatants we selected a lung adenocarcinoma cell line (Calu-3), which demonstrated an over-expression of p185HER2 measured as the reactivity with polyclonal rabbit serum to the 14-amino-acid carboxy-terminal-HER2/neu. Two MAbs, designated MGR2 (IgG1) and MGR3 (IgG2), selected for reactivity on Calu-3 and negativity on A43I live cells, the reference target cell for EGF receptor expression, were found to immunoprecipitate a 185-kDa molecule. Immunodepletion experiments with the polyclonal antiserum and cross-competition experiments indicated that the 2 reagents recognized 2 different epitopes located on the p185HER2 molecule. One of the 2 MAbs, MGR3, was found to internalize, induce p185HER2 phosphorylation and inhibit tumor cell growth in vitro. These results indicate that MGR3 is directed against a determinant located in the p185HER2 ligand binding site and may compete with the p185HER2 ligand, but is incapable of inducing a complete mitotic signal.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Monoclonal / isolation & purification
  • Antibodies, Monoclonal / pharmacology*
  • Biological Transport
  • Cell Division*
  • Cell Line
  • Gene Amplification*
  • Humans
  • Kinetics
  • Mice
  • Mice, Inbred BALB C / immunology
  • Neoplasms
  • Phosphorylation
  • Protein-Tyrosine Kinases / genetics
  • Proto-Oncogene Proteins / genetics*
  • Proto-Oncogene Proteins / immunology
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogenes*
  • Receptor, ErbB-2


  • Antibodies, Monoclonal
  • Proto-Oncogene Proteins
  • Protein-Tyrosine Kinases
  • Receptor, ErbB-2