Evidence for the differential expression of a variant EGF receptor proteinin human prostate cancer

Earlier studies have demonstrated an unexplained depletion of the epidermal growth factor receptor (EG FR) protein expression in prostatic cancer. We now attribute this phenomenon to the presence of a variant EGFR (EGFRvIII) that is highly expressed in malignant prostatic neoplasms. In a retrospecti ve study, normal, benign hyperplastic and malignant prostatic tissues were examined at the mRNA and protein levers for the presence of this mutant rec eptor. The results demonstrated that whilst EGFRvIII was not present in nor mal prostatic glands, the level of expression of this Variant protein incre ased progressively with the gradual transformation of the tissues to the ma lignant phenotype. The selective association of high EGFRvIII levels with t he cancer phenotype underlines the role that this mutant receptor may maint ain in the initiation and progression of malignant prostatic growth, and op ens the way for new approaches in the management of this disease including gene therapy. (C) 2000 Cancer Research Campaign.