The putative role of transforming viruses in childhood acute lymphoblastic leukemia.

Epidemiological evidence suggests that infection is involved in the etiology of common acute lymphoblastic leukemia, either by stimulating an inappropriate immune response or in the form of a classical transforming agent. In an attempt to elucidate the role that infection is playing in this disease, we used representational difference analysis (RDA) to examine tumor samples for the presence of exogenous genomes. Twenty RDA experiments were carried out, using four different restriction enzymes, but no exogenous sequences were identified within leukemic cells. These results suggest that it is unlikely that a single, direct transforming agent is involved in the pathogenesis of common acute lymphoblastic leukemia.