Expression of proto-oncogenes in xenografts of human renal cell carcinomas.

In a recent paper, we described the expression pattern of proto-oncogenes in primary human renal cell carcinoma [12]. To test the possibility of using xenografts as a useful alternative for such studies, we analyzed xenografts of a number of human renal cell carcinomas in nu/nu mice. Xenografts included RC2, RC14, RC21, RC43 and NC65. Northern blot analysis indicated that c-Ras was expressed in all these xenografts. The identity of the ras transcripts in the individual xenografts was further specified as c-Ha-ras, c-Ki-ras or N-ras. Expression of c-myc and the p53 gene was also found in a number of these tumors. Only RC21 failed to express the c-myc or the p53 gene. In all xenografts, a 3.0 kb c-fes/fps mRNA was present. In RC2, RC14, RC21 and RC43, low levels of the 4.8 kb ab 1 transcript were detectable. Transcripts of myb and sis could not be detected in any of the xenografts. The results indicated that the expression pattern of a variety of proto-oncogenes in xenografts of human renal cell carcinomas was similar to that in the primary tumors.