CONCOMITANT OVEREXPRESSION OF THE EGFR AND ERBB-2 GENES IN RENAL-CELLCARCINOMA (RCC) IS CORRELATED WITH DEDIFFERENTIATION AND METASTASIS

Gene amplification or structural alteration of different erbB genes ex erts a transforming effect in a variety of human neoplasms. Overexpres sion of the EGF receptor is associated with tumor initiation and progr ession of renal cell carcinoma (RCC). However, the role of erbB-2 in t hese processes remains unknown. We investigated 34 venal cell carcinom as for gene amplification and expression of the EGFR and erbB-2 genes at the mRNA and protein level and their relationship to pathological a nd clinical parameters. No amplification of both genes has been observ ed. However, high expression of the EGF receptor protein and p185erbB2 was frequent in RCC and statistically significantly related to higher tumor grades. We could demonstrate a close correlation of p185erbB2 o verexpression with high EGF receptor levels. Co-overexpression of both receptor types was significantly associated with metastatic disease. Our results suggest a synergistic involvement of both EGF receptor and p185erbB2 in the progression of RCC. (C) 1996 Wiley-Liss, Inc.