RNA tumor viruses and human lymphomas.

We have used molecular hybridization to detect virus-specific RNA in tumors ( I ) , and have found that corresponding neoplasias of murine and human origin exhibit remarkable similarities. Thus, human breast carcinomas contained (2) RNA possessing sequence homology to that of mouse mammary tumor virus (MMTV). This type of RNA was unique to the malignant adenoand medullary-carcinomas, being undetectable in normal breast tissue and in such benign pathologies as fibrocystic disease and fibroadenoma. In keeping with the known unrelatedness of the murine leukemogenic and mammary tumor viruses, we found that breast Cancer RNA did not hybridize to DNA complementary to the RNA of Rauscher leukemia virus (RLV). Finaly, and more compelling, was the demonstration that human leukemic cells (3) and human lymphomas (4), including Burkitt's disease (5), contain RNA showing homology to that of Rauscher leukemia virus and not to that of mouse mammary tumor virus.