Nuclear DNA sequences present in human leukemic cells and absent in normal leukocytes.

The central purpose of the present study was to test the proposition that the nuclear DNA of every human cell contains whatever information is necessary and sufficient for transformation to malignancy. The experiments were made possible by our earlier identification in human leukemic cells of particulate elements encapsulating 70S RNA and RNA-directed DNA polymerase. The [(3)H]DNA synthesized by these particles was used as a probe, through molecular hybridization, to normal and leukemic DNA. The results obtained establish that leukemic nuclear DNA contains particle-related sequences that cannot be detected in normal leukocytes. This outcome does not support the virogene-oncogene theory, which postulates the inclusion of at least one complete copy of oncogenic information in the genome of every normal cell. The data suggest that we may not be forced to cope with an omnipresent DNA segment coding for malignancy. Under the circumstances, we can perhaps entertain more hopeful pathways leading to the control and cure of cancer.