Increased expression of the epidermal growth factor receptor on human colon carcinoma cells
S. J. Bradley, G. Garfinkle, E. Walker, R. Salem, L. B. Chen and G. Steele Jr
Epidermal growth factor (EGF) is a small polypeptide hormone that promotes
the growth of cells in culture and elicits the differentiation of
epithelial tissues in vivo. The effect of EGF is mediated by a
transmembrane receptor that is expressed in increased amounts on some tumor
cells. We have used a monoclonal antibody to the EGF receptor to detect
increased expression of the receptor on human colon carcinoma cells. All
eight of the moderately well-differentiated colon carcinoma cell lines
tested and several frozen colon carcinoma tissue sections showed increased
expression of the EGF receptor, while five poorly differentiated colon
carcinoma cell lines and normal colon tissue sections did not. Increased
expression of the EGF receptor on moderately well-differentiated colon
carcinoma cells but not on poorly differentiated colon carcinoma cells was
also demonstrated by western transfer and iodine 125-labeled EGF binding
assays. Increased expression of the EGF receptor on moderately
well-differentiated colon carcinoma cells seems to be a useful marker for
the differentiation of human colon carcinoma cells. In addition, it might
provide a site for adjuvant hormonal therapy or immunotherapy.
