title: [The level of EGF receptor expression effects its transactivation by IFN gamma in epithelial cells].
abstract: Earlier, we demonstrated transactivation of the epidermal growth factor receptor (EGFR) in response to interferon gamma (IFNgamma) in epidermal carcinoma A431 cells. It was shown that IFNgamma-induced EGFR transactivation is impossible in some cancer epithelial cells. Here, we hypothesize that IFNgamma-dependent EGFR transactivation in these cells correlates with EGFR quantity on the cell surface. To test this suggestion, a line of stably transfected HEK293 cells (HEK293delta99 cells) expressing high level of mutant EGFR lacking 99 C-terminal residues has been established. HEK293delta99 cells demonstrated EGFR transactivation in response to IFNgamma unlike the parent HEK293 cells, in which transactivation lacked. In HEK293delta99 and A431 cells, the time courses of EGFR activation induced by IFNgamma have the same pattern. In HEK293delta99 cells like A431, IFNgamma-induced EGFR transactivation requires EGFR kinase activity and occurs via autophosphorylation mechanism. Taken together, these data provide direct evidence of the dependence of IFNgamma-induced EGFR transactivation upon EGFR expression level in epithelial cells.
authors.forename: I V
authors.initials: IV
authors.lastname: Gonchar
authors.forename: V N
authors.initials: VN
authors.lastname: Dorosh
authors.forename: N N
authors.initials: NN
authors.lastname: Nikol'skiĭ
authors.forename: E B
authors.initials: EB
authors.lastname: Burova
mesh_terms: D045744:Cell Line, Tumor; D004847:Epithelial Cells / Q000187:drug effects / Q000201:enzymology; D066246:ErbB Receptors / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism* / Q000494:pharmacology; D010766:Phosphorylation; D015398:Signal Transduction; D015533:Transcriptional Activation / Q000187:drug effects; D014162:Transfection
chemical_list: D007371:Interferon-gamma; D066246:ErbB Receptors