Human Acute Myelogenous Leukemia Research Articles

Immunological and biochemical characterisation of type C viruses isolated from cultured human AML cells

TYPE C viruses are associated in several species with naturally occurring malignancy and have been isolated from a variety of species including several non-human primates. The ability to specify interviral relationships is crucial for evaluating the degree of relatedness of new isolates to known viruses, especially those which are potentially associated with human malignancy. Recent studies of Gallagher and Gallo1 indicated the presence of a type C virus in cultured cells from a patient with acute myelogenous leukaemia (AML) (patient A.S.). Viruses from this culture have been propagated in homologous and heterologous fibroblastic cells2 in sufficient quantity to be characterised in detail.

Acute Myelogenous Leukemia of the Wistar/Furth Rat: Establishment of a Continuous Tissue Culture Line Producing Lysozyme In Vitro and In Vivo

A transplantable myelogenous leukemia of an inbred Wistar/Furth rat has been established in tissue culture and cloned. The resulting transplantable leukemia line demonstrates in vitro doubling time of 20 hr, colony-forming efficiency of 5% in liquid and methylcellulos-containing medium, and a saturation density of 3.0 x 106 cells/sq cm in liquid medium. Following intraperitoneal inoculation, newborn rats developed solid tumors, ascities, and leukemia with ld50 of5 x 103 cells and mean latency of 60 days. The tumor cell morphology was consistent with that of acute myelogenous leukemia. Histochemical staining for myeloid enzymes revealed no evidence of myeloperoxidase, esterase, or leukocyte alkaline phosphatase; however, fluorescent antibody staining for lysozyme was markedly positive. Serum, urine, and ascitic fluid from rats with transplanted leukemia also contained elevated levels of lysozyme. There was no detectable type-CRNA virus production by this cell line after as long as 100 days in vitro. This inbred rat myelogenous leukemia should provide a useful model for studies of chemotherapy and immunoltherapy of human acute myelogenous leukemia.

Acute myelogenous leukemia of the Wistar/Furth rat: establishment of a continuous tissue culture line producing lysozyme in vitro and in vivo

A transplantable myelogenous leukemia of an inbred Wistar/Furth rat has been established in tissue culture and cloned. The resulting transplantable leukemia line demonstrates in vitro doubling time of 20 hr, colony-forming efficiency of 5% in liquid and methylcellulos- containing medium, and a saturation density of 3.0 x 106 cells/sq cm in liquid medium. Following intraperitoneal inoculation, newborn rats developed solid tumors, ascities, and leukemia with ld50 of5 x 103 cells and mean latency of 60 days. The tumor cell morphology was consistent with that of acute myelogenous leukemia. Histochemical staining for myeloid enzymes revealed no evidence of myeloperoxidase, esterase, or leukocyte alkaline phosphatase; however, fluorescent antibody staining for lysozyme was markedly positive. Serum, urine, and ascitic fluid from rats with transplanted leukemia also contained elevated levels of lysozyme. There was no detectable type-CRNA virus production by this cell line after as long as 100 days in vitro. This inbred rat myelogenous leukemia should provide a useful model for studies of chemotherapy and immunoltherapy of human acute myelogenous leukemia.

C-type virus antigens detected by immuno-fluorescence in human bone tumour cultures

IN several animal species, C-type oncogenic RNA viruses (oncornaviruses) cause malignant tumours of mesodermal origin, such as leukaemia, lymphomas and different kinds of sarcoma1. C-type oncornaviruses have rarely been observed in human mesenchymal neoplasms using electron microscopy2,3, but it has been claimed that molecular-biological methods can demonstrate in the tumours the presence of entities, the nucleic acids of which have sequences in common with the genomes of known mammalian oncornaviruses4–7. There have also been claims that C-type viruses can be detected in tissue cultures of human tumours8–10, although it seems that a contamination with an animal virus had occurred in these cases. Recently11 an agent with type C RNA tumour virus characteristics has been isolated from cultured human acute myelogenous leukaemia cells.

Type C RNA tumor virus isolated from cultured human acute myelogenous leukemia cells.

Previously, type C RNA tumor virus-related components have been described in blood leukocytes from patients with acute myelogenous leukemia. These components, for example, reverse transcriptase, have been shown to be most closely related to those from two oncogenic subhuman primate type C viruses (woolly monkey sarcoma virus and gibbon ape leukemia virus). Now, we report the continuous production of budding type C viruses with the same characteristic reverse transcriptase by three separate culturings of leukocytes from a single bleeding from a patient with acute myelogenous leukemia. These isolations were made possible by the discovery of a source of conditioned media which sustains exponential growth of human myelogenous leukemia cells in liquid suspension culture.

Functional cellular maturation in cultures of human haematopoietic cells.

Summary. The capacity of cells grown in colonies derived from human haematopoietic cells to phagocytize bacteria and to reduce nitroblue tetrazolium (NBT) was studied as a measurement of functional maturation. Marrow cells from 12 non‐leukaemic patients, fivc patients with acute non‐lymphocytic leukacmia, and cells taken from a myeloblastic cell line established from a patient with acute myelo‐genous leukaemia (AML) were studied. Cells were cultured in soft agar with normal human leucocyte feeder layers as the source of stimulating factor. While the leukaemic marrows gave rise to fewer colonies than the non‐leukaemic marrows, colony formation by the AML cell line was extensive. In all instances colony formation was completely dependent upon the presence of the leucocyte feeder layers. Suspensions of pooled colonies contained 42% mature granulocytes in non‐leukaemic cultures and 41% in the leukaemic cultures. Granulocytes from these cultures showed active phagocytosis of Staphylococcus aureus and reduction of NBT. In cells taken directly from the liquid suspension culture of the AML cell line, no mature granulocytes nor phagocytosis were noted, whereas 35% and 26% of the cells removed from the colonies formed by these cells were classified as mature granulocytes, or demonstrated phagocytosis and NBT reduction respectively. These observations indicate that granulocytes in soft agar colonies derived from human haematopoietic cells are functionally mature, and that cells derivcd from a human AML cell line have the capacity to form colonies with normal maturation, if they are provided with an appropriate stimulating factor.