K-ras oncogene mutations in neoplasias of kidney transplanted patients: preliminary results with a new technique.

K-ras oncogene activations by point mutations are frequent in many forms of human cancers but there is a special category of cancers occurring in immunosuppressed patients after kidney transplantation in which the frequency of K-ras oncogene activation has not been fully studied. We used a new sensitive and easy method for the detection of this mutation, and in 8 DNA samples studied from various neoplasias of 8 patients after kidney transplantation, we found 4 mutations. Our preliminary results indicate that the activation of K-ras oncogene at codon 12, is a common event among the kidney transplanted patients who present a neoplasia, even in the least aggressive forms of the disease, contrary to the sporadic cases.