C-MYC, C-ERBB-1 AND C-ERBB-2 EXPRESSIONS IN UROTHELIAL CARCINOMA

The expression of c-myc, c-erbB-1 and c-erbB-2 in 24 cases of urotheli al carcinoma by Southern and northern blot analysts, and immunohistoch emistry was examined. The results were compared with the pathological grade and stage. We found elevated mRNA expressions of c-myc and c-erb B-1 in 19 and 11 of 21 cases, respectively, but there was no apparent amplification or rearrangement of these oncogenes in any of the cases examined. By immunohistochemistry using anti-epidermal growth factor r eceptor antibody, most of the cases showed positive immunoreactivity o n the cancer cell membranes, and cancers of higher pathological grade and stage showed more intense staining. By contrast, amplification of c-erbB-2 was detected in four of 24 cases, all of which were assigned to a high pathological grade (G3). Elevated c-erbB-2 mRNA levels appea red to correlate with the pathological grade of the cancers. Positive immunohistochemical reactions to c-erbB-2 were found in the cancer cel l membranes in three of 24 cases, which were accompanied by amplificat ion and elevated mRNA levels of c-erbB-2. Tn conclusion, expressions o f c-myc, c-erbB-1 and c-erbB-2 were all elevated in the majority of ur othelial carcinomas, but the amplification was not universal.