AMPLIFICATION AND EXPRESSION OF THE C-ERB B-2/NEU PROTOONCOGENE IN HUMAN BLADDER-CANCER

The c‐erb B‐2/neu gene encodes a cell‐surface glycoprotein with extensive homology to, but distinct from, the epidermal growth‐factor receptor. In this study, we compared the c‐erb B‐2/neu gene amplification and expression of tissue specimens obtained from the bladders of normal controls and patients with high‐grade transitional cell bladder carcinoma. Southern blot analysis of DNAs from 24 patients and 5 controls showed 2 cases of c‐erb B‐2/neu gene amplification in patients and none in controls. Western blot analysis demonstrated that c‐erb B‐2/neu was expressed in 67.6% (23/34) of patient specimens but in none of the controls (0/5). This finding agreed with the result of immunohistochemical staining, which showed that tissue from 74.3% (26/35) of the patients and none of the controls (0/7) showed positive immunofluorescence staining. This is the first report suggesting that c‐erb B‐2/neu gene amplification and expression may be associated with human bladder carcinogenesis. Copyright © 1990 Wiley‐Liss, Inc., A Wiley Company