[Expression of EGF receptor subfamily in tumor].

The members of EGF receptor subfamily are transmembrane glycoproteins with tyrosine kinase activity. Once EGF or EGF-related peptides binds to the receptors, they undergo autophosphorylation and binding to the SH2 protein, which in turn activates the intracellular signaling cascade. In the squamous carcinoma of head and neck, esophagus and lung, the EGF receptor gene amplification and EGF receptor hyperproduction are frequently observed. In the adenocarcinoma of pancreas, breast and stomach, hyperproduction of the EGF receptor subfamily is common, suggesting the involvement of these growth factor receptors in the tumorigenesis. The prognostic value of EGF receptor hyperproduction appears considerable when combined with other factors. EGF receptor subfamily members are useful targets for the immunotoxin therapy and immunogene therapy.