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Expression of the C‐ erb B‐3 protein in gastrointestinal tract tumours determined by monoclonal antibody RTJ1
Author(s) -
Rajkumar Thangarajan,
Goden Calvin S. R.,
Lemoine Nicholas R.,
Gullick William J.
Publication year - 1993
Publication title -
the journal of pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.964
H-Index - 184
eISSN - 1096-9896
pISSN - 0022-3417
DOI - 10.1002/path.1711700309
Subject(s) - monoclonal antibody , polyclonal antibodies , immunohistochemistry , microbiology and biotechnology , antibody , biology , gastrointestinal tract , staining , immunoprecipitation , epithelium , monoclonal , pathology , medicine , immunology , biochemistry , genetics
We have examined the expression of the c‐ erb B‐3 protein in a wide range of tumours of the gastrointestinal (GI) tract using immunocytochemical staining. Two antibodies were employed, a polyclonal antibody, 49.3, and a new monoclonal antibody, RTJ1, both raised to a synthetic peptide from the cytoplasmic domain of the human c‐ erb B‐3 protein. The antibodies recognize c‐ erb B‐3 by immunoprecipitation and Western blotting of lysate prepared from a cell line engineered to overexpress the protein. Both antibodies also detect expression of the protein in formalin‐fixed, paraffin‐embedded human tissues. The RTJ1 monoclonal antibody gave superior staining, showing lower background and more pronounced cell surface immunoreactivity. The c‐ erb B‐3 protein was found in normal epithelial cells throughout the GI tract, in squamous epithelium of the oropharanyx and oesophagus, in the parietal cells of the stomach, and in the surface enterocytes of the small and large bowel. Seventy‐six tumours arising at these sites were examined for c‐ erb B‐3 protein expression. Widely varying levels of expression were seen, from absent to intense staining with cell membrane accentuation.