GENETIC PREDISPOSITION TO TRANSPLACENTALLY INDUCED RENAL-CELL CARCINOMAS IN THE EKER RAT

N-Ethyl-N-nitrosourea-induced transplacental renal carcinogenesis in t he rat results primarily in Wilms' tumors, apparently because primitiv e nephroblasts are the preferred target. Our question is whether N-eth yl-N-nitrosourea-induced mutations in the fetal kidney would increase the number of adult-type renal cell carcinomas in the Eker rat, which is heterozygous for a mutation that predisposes to renal cell carcinom a. Surprisingly, renal cell tumors but no Wilms' tumors began to appea r from as early as 1 week after birth. Thus, the inheritance of a rena l cell carcinoma mutation determines the specificity of tumor histolog y even with in utero carcinogenesis.