Viral-related information in oncornavirus-like particles isolated from cultures of marrow cells from leukemic patients in relapse and remission

Abstract

Characterization of ribonucleic acid content of particles released from cultures of marrow cells of leukemic patients indicates the presence of RNA molecules of size and base sequence characteristic of oncornaviruses. Seventeen marrow samples obtained from leukemic patients in relapse or in a chronic phase of the disease yielded particles containing high molecular weight RNA with a sedimentation velocity (about 70 S) similar to that obtained for murine oncornavirus RNA. Eight of nine marrow samples from non leukemic patients did not yield detectable high molecular weight RNA. Among patients in firm hematological remission, three of three samples from patients with acute lymphoblastic leukemia and three of nine samples from patients with acute myeloblastic leukemia were positive for high molecular weight RNA. The base sequence of the RNA in particles was characterized by synthesizing complementary [3H]DNA in an endogenous reaction and hybridizing to excess RNA from known oncornaviruses. Hybridization of 40-60% of input complementary DNA to simian sarcoma virus RNA was detected. No homology was detected with an avian oncornavirus (Rous sarcoma virus) while an intermediate level of homology (10-30%) was detected in hybridization to murine sarcoma virus (Kirsten) and murine leukemia viruses (Rauscher, Moloney, and Gross).