Oncornavirus-like particles from cultured bone marrow cells preceding leukemia and malignant histiocytosis.

Abstract

ABSTRACr Particles with the density and enzymatic activity characteristic of known oncornavirus have been previously described' in bone marrow cells from patients with leukemia in relapse and in remission. We have confirmed these findings and studied two patients in whom preleukemia was among the diagnostic considerations. Following cultivation of bone marrow from these patients for 1 week in conditioned media with dexamethasone, a high-speed pellet of the supernatant fluid and disrupted cells was prepared and analyzed on a sucrose gradient for enzymatic activity characteristic of RNA-directed DNA polymerase (reverse transcriptase). Peaks of endogenous DNA polymerase activity showing ribonuclease sensitivity and/or stimulation with the synthetic template poly(rC)dG~hs218 were demonstrated in both patients at densities of 1.15 to 1.19 and 1.21 to 1.24 g/ml. Subsequently diagnosis 2 and 4 months after initial evaluation 'revealed acute myelogenous leukemia and malignant histiocytosis, respectively. Prior studies have suggested a possible etiological significance of such particles in human leukemia. The demonstration of similar particles preceding clinically overt disease in these patients supports this hypothesis and offers the possibility of early diagnosis and treatment.A cytoplasmic particle with the density, high-molecularweight RNA, and RNA-dependent DNA polymerase characteristic of known RNA tumor viruses has been demonstrated in malignant cells from patients with leukemia (1-3). Following cultivation with conditioned media, Mak et al. have demonstrated an increase and release of such particles from cells of leukemic patients both in relapse and in firm hematological remission with no evidence of disease (3, 4). Molecular hybridization (5-7) and immunological studies (8,9) have added significance to these particles by demonstrating a close relationship between them and known oncogenic agents of primate origin, confirming earlier reports of homology between nucleic acid of human leukemia cells and murine leukemia virus (10,11).We now report studies of two patients in whom, on the basis of history and clinical and laboratory examination, the possibility of preleukemia was considered as part of the differential diagnosis. Extensive investigation of both patients failed to reveal any definite histological evidence to support the diagnosis of leukemia. Bone marrow obtained at that time from both patients showed clear biochemical evidence of oncornavirus-like particles 2 and 4 months prior to the diagnosis of acute myelogenous leukemia and malignant histiocytosis, respectively. MATERIALS AND METHODS Patient Material. Bone marrow from these two patients and from patients with either acute myelogenous leukemia (AML) or chromic myelogenous leukemia (CML) was obtained by aspiration from the posterior iliac crest. Peripheral blood was used in cases with high peripheral blast counts. Normal bone marrow was obtained from three normal marrow donors in the course of bone marrow transplantation.Method of Cultivation. Bone m...

Human preleukaemia cell culture studies in sideroblastic anaemia

“…The finding of virus-like reverse transcriptase production by the cells of patients reported here, and by Vosika et al (1975) must be confirmed more widely before definite prognostic or aetiological implications are possible. In addition, however, studies such as this support the as yet unproven contention that characteristics displayed by cells in culture are relevant to their behaviour in normal and pathological states in vivo.…”

“…STUDIES of leukaemic cells in cultures have revealed a variety of abnormalities; these include changes in the number and proliferative response of granulopoietic progenitors (Senn, McCulloch and Till, 1967;Metcalf et al, 1972;Moore et al, 1974;Curtis et al, 1975), a reduction in the number of species of molecules capable of stimulating granulopoiesis in culture (Price et al, 1975a) and the release of leukoviruses (Gallagher and Gallo, 1975) or leukovirus-like particles (Mak et al, , 1975aVosika et al, 1975). The finding of these abnormalities has led to a search for similar changes in conditions with a high probability of becoming leukaemic; abnormalities have been found in colony formation (Greenberg, Nichols and Schrier, 1971;Senn and Pinkerton, 1972) and maturation in culcure (Golde and Cline, 1973).…”

Antibodies in human sera to oncorna virus-like proteins from normal or leukemia marrow cell cultures.

“…The bulk of this evidence rests upon reverse transcriptase studies (1)(2)(3), DNA-RNA hybridization homologies (4,5), immunochemical analysis of viral-like antigens in human tissues (6)(7)(8), and the isolation of C-type viruses from human tissues (9)(10)(11). Recently, Mak et al (12) and Vosika et al (13) reported that some human marrows in culture-released particles with some physical and biochemical properties resembling those of oncornaviruses. We have undertaken to examine the immunological properties of particles obtained in similar marrow culture supernates, particularly with regard to (a) whether they contain determinants cross-reactive with mammalian RNA tumor viruses and (b) whether antibodies to such determinants occur spontaneously in human sera.…”