Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Kirsten murine sarcoma virus (Ki-MSV) transformed Balb/eT3 mouse cells (K-Balb) were found to have altered membrane glycoconjugates compared to normal Balb/3T3 cells. There were reduced amounts of mono- and disialogangliosides, GM1 and GD1a, and activity of the specific galactosyltransferase required for synthesis of these gangliosides was reduced to between 0 and 18.5% of normal in the several K-Balb clones examined. When fucose-labeled glycopeptides derived from the surfaces of Balb/3T3 and K-Balb cells were compared by gel filtration chromatography, the glycopeptides from the transformed cells were enriched in earlier eluting components. These differences were also observed when the glycopeptides were derived from the entire cell and were diminished when the surface or cellular glycopeptides from Balb/3T3 and K-Balb were digested with neuraminidase prior to chromatographic analysis. Changes in these membrane sialoglycolipids and sialoglycopeptides were not influenced by Rauscher leukemia virus infection. In marked contrast, these changes in membrane glycoconjugates were not observed in Wooley monkey sarcoma virus (WSV) transformed Balb/3T3 cells (W-Balb). Although W-Balb cells like K-Balb were transformed by tissue culture criteria, their ganglioside composition, galactosyltransferase activity, and glycopeptide patterns were similar to normal Balb/3T3. These findings have potential implications concerning the role of these complex carbohydrates in the phenotypic alterations of transformed cells.
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PMID:A comparison of membrane glycoconjugates from mouse cells transformed by murine and primate RNA sarcoma viruses. 17 12

Cell surface binding fluorescent ligands have been used to distinguish between different types of leukaemic cells and between leukaemic cells and their presumed normal counterparts or progenitors. Binding of these probes was evaluated using the Fluorescence Activated Cell Sorter (FACS) which provides both rapid, objective and quantitative recording of fluorescent signals from individual cells plus physical separation of cells of particular interest. Binding sites for cholera toxin (monosialoganglioside GM1) were found to be normally expressed in chronic leukaemias but greatly diminished or absent in acute leukaemias irrespective of their morphological type. Antibodies specific for the common form of acute lymphoblastic leukaemia (ALL, non-T, non-B) have been produced in rabbits. After extensive absorption and testing these were shown to define a cell surface antigen of non-T, non-B type ALLs. The antigen is absent from other leukaemias with two interesting exceptions--the majority of acute undifferentiated leukaemias express the antigen as do a proportion of chronic granulocytic leukaemias in blast crisis relapse. The anti-ALL antibodies can therefore be used to distinguish different leukaemias and, more significantly, can identify the existence of relatively rare leukaemic cells in the blood of untreated patients and the marrow of treated patients considered to be in remission.
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PMID:Analysis of human leukaemic cells using cell surface binding probes and the fluorescence activated cell sorter. 79 43

Previous work has shown that nude (nu/nu) mice additionally immunosuppressed by splenectomy, sublethal irradiation, and treatment with antiasialo GM1 antiserum (SIA-nu/nu mice) have no detectable natural killer activity and allow the growth of human malignant lymphoblasts. We show here that all SIA-nu/nu mice engrafted intravenously with 5 x 10(6) malignant lymphoblasts originally derived from a child with a T-cell acute lymphoblastic leukemia (PF382) and from a boy with a T-cell lymphoma (ST-4) develop lethal meningeal leukemia and die within 35 days. Histologic examination of moribund SIA-nu/nu mice showed that vertebral and skull bone marrow was always replaced by proliferating human T lymphoblasts. From the spinal canal, lymphoblasts spread to the meninges, causing hind leg paralysis. Leaving the skull, they permeated the meninges and then invaded the nervous parenchyma. This efficient and reproducible experimental model may be suitable for experimental studies on the pathogenesis of meningeal leukemia.
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PMID:Growth and spread of human malignant T lymphoblasts in immunosuppressed nude mice: a model for meningeal leukemia. 151 43

We established five murine monoclonal antibodies (MAbs) specific for a-pathway ganglio-series gangliosides by immunizing C3H/HeN mice with these purified gangliosides adsorbed to Salmonella minnesota, followed by fusion with mouse myeloma cells. The binding specificities of these MAbs were determined by enzyme-linked immunosorbent assay and immunostaining on thin-layer chromatogram. These five MAbs, designated GMR6, GMB28, GMB16, GMR17, and GMR11 reacted strongly with the gangliosides GM3, GM2, GM1, GD1a, and GT1a, respectively, that were used as immunogens. Three MAbs, GMB28 (anti-GM2), GMB16 (anti-GM1), and GMR11 (anti-GT1a) showed highly restricted binding specificities, reacting only with the immunizing ganglioside. None of the other various authentic gangliosides or neutral glycolipids was recognized. On the other hand, the other two MAbs, GMR6 (anti-GM3) and GMR17 (anti-GD1a) exhibited broader specificities. MAb GMR6 cross-reacted with GM4, GM1b, GD1a, GT1b, and IV3NeuAc alpha-nLc4Cer. MAb GMR17 also reacted with GM1b and GT1b. Neither GMR6 nor GMR17 reacted with other gangliosides or neutral glycolipids tested. Using these MAbs, we determined the expression of these gangliosides, especially GM1, GD1a, and GT1a on mouse, rat and human leukemia cells. GM1 and GD1a were expressed on some leukemia cells, whereas GT1a was not detected in these cells.
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PMID:Generation of one set of monoclonal antibodies specific for a-pathway ganglio-series gangliosides. 162 99

Athymic nu/nu mice are commonly employed for the heterotransplantation of solid human tumors. Leukemias, however, have consistently proved difficult to transplant and, to enhance their take, recipient nu/nu mice have been variously immunosuppressed. In this study, the natural reactivity against human malignant T lymphoblast (PF382) of splenectomized nu/nu mice (S-nu/nu), nu/nu mice splenectomized and treated with polyinosinic-polycytidylic acid (SIC-nu/nu), and nu/nu mice splenectomized, irradiated and repeatedly injected with antiasialo GM1 antiserum (SIA-nu/nu) has been correlated with the in vivo growth of subcutaneous and intravenous PF382 cell challenges. SIC-nu/nu mice display a marked natural killer (NK) activity, quickly clear 125I-Urd-labelled PF382 cells injected intravenously and do not allow the growth of subcutaneous nor intravenous PF382 cell challenges. S-nu/nu mice display a slightly lower NK activity and slower clearance of 125I-Urd-labelled PF382 cells. Moreover, an intravenous PF382 cell challenge kills 56% of S-nu/nu mice. SIA-nu/nu mice have no NK activity, slowly clear 125I-Urd-labelled PF382 cells and always allow the growth of PF382 cells injected either subcutaneously or intravenously with a consistent pattern. Following the intravenous challenge, PF382 cells first metastasize to liver and kideny, then focal or diffuse infiltrations of the bone marrow and menings become evident. SIA-nu/nu mice thus offer an interesting experimental model for study of the pathogenesis of leukemic infiltration of the meninges, and the exploration of possible therapeutic approaches.
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PMID:Growth and dissemination of human malignant lymphoblasts in immunosuppressed nu/nu mice. 175 67

The Rauscher murine leukemia retrovirus system provides an in vivo model of the human acquired immune deficiency syndrome for testing the ability of antiviral agents and biological response modifiers (BRM) to suppress viremia and retroviral disease. In the present report we examined three agents in the Rauscher retrovirus model: imexon, Ampligen and poly[I,C]-LC. Imexon reduced splenomegaly, viremia, and serum reverse transcriptase levels even when treatment was not initiated until 7 days after virus infection. Imexon also significantly prolonged the survival of infected mice. Thus it proved to be an effective antiviral agent in this system, although imexon did not completely eliminate retroviral infection in treated mice. Poly[I,C]-LC and Ampligen had immunomodulatory effects. Both of these BRM augmented the cytolytic activity of splenic natural killer (NK) cells in infected animals when treatment was initiated 24 h after infection. Poly[I,C]-LC had antiretroviral activity when administered on this schedule. In order to examine the role of NK cell augmentation in the antiviral activity of poly[I,C]-LC, we attempted to deplete NK activity by treatment with rabbit antibody to asialo GM1, a ganglioside on the surface of murine NK cells. Combined treatment of infected mice with poly[I,C]-LC and anti-asialo GM1 decreased the antiviral activity of poly[I,C]-LC. This finding suggests that NK cells may be involved in the antiviral effect of this BRM.
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PMID:Imexon and biological response modifiers in murine models of AIDS. 182 6

We have studied the glycolipid composition of six different murine myelogenous leukemias as well as that of T-cell leukemias and normal spleen cells. Neutral and acidic lipid fractions were isolated by column chromatography on DEAE-Sephadex and analyzed by high-performance thin-layer chromatography (HPTLC) and an HPTLC overlay method. Murine myelogenous leukemias were found to contain globo- and ganglio-series neutral glycolipids, e.g., glucosylceramide (Glc-cer), lactosylceramide (Lac-cer), globotriaosylceramide (Gb3), globoside (Gb4), Forssman glycolipid (Gb5), and asialo-GM1 (GA1). Monoblastic leukemia cells contained increased proportions of Gb3, Gb4, Gb5, and GA1. Monocytic and myelomonocytic leukemia cells contained increased proportions of Glc-cer and Lac-cer. Especially, Glc-cer accounted for approximately 60% of the total neutral glycolipids in monocytic leukemia cells. Gb3 was the major neutral glycolipid in reticulum cell neoplasm type A, and it accounted for approximately 75% of the neutral glycolipids. GA1 was the major neutral glycolipid in myeloblastic and granulocytic leukemia cells as well as T-cell leukemias. Especially, granulocytic leukemia cells contained predominantly GA1, and it accounted for approximately 80% of the total neutral glycolipids. The pattern of gangliosides in myelogenous leukemias was more complex when compared with that of the neutral glycolipids; murine myelogenous leukemias contained at least 13 gangliosides, including such major gangliosides as GM1, GM1b containing N-acetyl neuraminic acid and N-glycolyl neuraminic acid, and Ga1NAc-GM1b. Alterations of glycolipid composition in murine myeloid leukemias may be associated with cellular differentiation and maturation, and therefore these characteristic glycolipid species may be regarded as markers for specific populations of leukemia cells.
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PMID:Glycolipid changes in murine myelogenous leukemias: neutral glycolipids as markers for specific populations of leukemias. 186 69

The role of acidic glycosphingolipids in cell growth and differentiation was investigated using the multipotent leukemia cell line K562. When GM3 was added to cell culture media, the growth of K562 cells was remarkably inhibited and the cells were shown to have megakaryocytoid morphology. Ultrastructural study demonstrated that K562 cells treated with GM3 had platelet peroxidase-positive structures, which were considered to be the specific marker of megakaryocyte. Furthermore, AP-3 directed against an epitope present on membrane glycoprotein IIIa reacted with the GM3-treated cells. Free N-acetylneuraminic acid, GM1, GM2, GD1a, and a mixture of bovine brain gangliosides containing GD1a and GT1b did not affect growth of K562 cells or show morphological changes. According to chemical analyses, GM3 content increased in megakaryocytoid differentiation induced by tetradecanoylphorbol-13-acetate, whereas GM3 decreased in erythroid differentiation induced by hemin. Enzymatic analysis showed that the GM3 increase during megakaryocytoid differentiation was a result of the sialyltransferase activation. These results indicated that exogenous GM3 induced differentiation of K562 cells into a "GM3-rich" lineage, i.e., mainly megakaryocytoid lineage, and that GM3 accumulation in the GM3-rich lineage was the result of the activation of GM3 synthase. These findings strongly suggested that GM3 ganglioside, a minor membrane component, has a crucial role in not only the differentiation induction but also the determination of the differentiation direction in pluripotent K562 cells.
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PMID:Ganglioside GM3 can induce megakaryocytoid differentiation of human leukemia cell line K562 cells. 200 80

The GM1 strain of feline leukaemia virus (FeLV) was isolated from a naturally occurring case of myeloid leukaemia and induces severe haematopoietic abnormalities, including myeloblastic leukaemia, on inoculation into cats. Molecular clones of FeLV-GM1 proviruses were obtained and studied by restriction enzyme mapping, blot hybridization and partial DNA sequence analysis. Two types of clone were isolated; the first was a replication-competent FeLV of subgroup A, resembling other low or minimally pathogenic FeLV-A isolates; the second was replication-defective with extensive deletions and mutations in gag and pol, although it has an intact env gene of subgroup B phenotype. Large segments of the defective proviruses, from the 5' leader sequence upstream of the gag gene to the 5' half of the env gene, show structural hallmarks of endogenous FeLV-related proviruses. Infectious FeLV-GM1 viruses recovered after transfection were tested for their leukaemogenic potential in newborn cats. Early polyclonal myeloproliferative changes were observed in cats inoculated with FeLV-A/GM1 alone, although these were more pronounced in animals receiving the full FeLV-AB/GM1 complex reconstituted by cotransfection of the defective virus FeLV-B with its FeLV-A helper. Analysis of viruses in the bone marrow showed that replication of the subgroup B component is delayed and restricted to a proportion of cats. Most of the infected cats developed persistent abnormalities of haematopoiesis and one progressed to disseminated myeloid leukaemia. The defective recombinant FeLV-B/GM1 appears to play an indirect but important role in myeloid leukaemogenesis.
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PMID:Molecular cloning and characterization of a defective recombinant feline leukaemia virus associated with myeloid leukaemia. 215 87

The diagnostic value of monoclonal antibodies is discussed. The expression of ICO-GM1 and ICO-G2 myeloid antigens in pediatric patients with nonlymphoblastic leukemia was associated with poor prognosis whereas patients with the expression of T-cell markers fared better. The prognostic value of the antigens was not altered by brief cytotoxic treatment. The prognosis for non-T-cell ICO-II+ type childhood lymphosarcoma was worse as compared to Ia+ICO-II- lymphoma subset. It was concluded that the biology of malignant cells and degree of cell differentiation (as assessed immunologically) affects treatment outcome significantly and should be considered in individualizing therapy for childhood lymphosarcoma and leukemia.
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PMID:[Immunologic prognosis in hemoblastoses in children]. 219 97


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