Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023467 (acute myeloid leukemia)
 35,200 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The physiologic balance between the two regulatory subunit isoforms, RI and RII, of cAMP-dependent protein kinase is disrupted in cancer cells; growth arrest and differentiation of malignant cells can be achieved when the normal ratio of these intracellular signal transducers of cAMP is restored by the use of site-selective cAMP analogs. In this study we evaluated the effects of the site-selective cAMP analog 8-chloroadenosine 3',5'-cyclic monophosphate (8-Cl-cAMP) on clonogenic growth of blast progenitors from 15 patients with acute myeloblastic leukemia and 3 patients affected by advanced myelodysplastic syndrome. Leukemic blast progenitors undergo terminal divisions, giving rise to colonies in methylcellulose. The self-renewal capacity of blast progenitors is conversely reflected in a secondary methylcellulose assay after exponential growth of clonogenic cells in suspension cultures. In all the samples tested, 8-Cl-cAMP, at micromolar concentrations (0.1-50 microM), suppressed in a dose-dependent manner both primary colony formation in methylcellulose and the recovery of clonogenic cells from suspension culture. Strikingly, in the samples from the entire group of patients, 8-Cl-cAMP was more effective in inhibiting the self-renewing clonogenic cells than the terminally dividing blast cells (P = 0.005). In addition, in four out of six cases studied, 8-Cl-cAMP was able to induce a morphologic and/or immunophenotypic maturation of leukemic blasts. An evident reduction of RI levels in fresh leukemic cells after exposure to 8-Cl-cAMP was also detected. Our results showing that 8-Cl-cAMP is a powerful inhibitor of clonogenic growth of leukemic blast progenitors by primarily suppressing their self-renewal capacity indicate that this site-selective cAMP analog represents a promising biological agent for acute myeloblastic leukemia therapy in humans.
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PMID:Inhibition of the self-renewal capacity of blast progenitors from acute myeloblastic leukemia patients by site-selective 8-chloroadenosine 3',5'-cyclic monophosphate. 132 84

An altered c-abl gene product (P210bcr-abl) possessing associated tyrosine protein kinase activity was recently been reported in several blast chronic myelogenous leukemia (CML) cell lines. We have examined different morphological types of leukocytes directly obtained from patients at the blast crisis stage of CML for expression of P210bcr-abl tyrosine protein kinase activity. Phosphorylation of P210bcr-abl in an immune complex kinase assay using an anti-v-abl peptide serum was observed in blast cells from four Philadelphia chromosome (Ph1)-positive CML patients in blast crisis. P210bcr-abl protein kinase activity was detected regardless of whether the blast cells were of myeloid, lymphoid, or undifferentiated morphology. P210bcr-abl protein kinase activity was not detected in immune complexes either from leukocytes of four Ph1-negative CML patients in blast crisis, of five acute myelogenous leukemia patients, or in the promyelocytic cell line HL-60. Mature myeloid cells are associated with an inhibitory factor for not only P210bcr-abl protein kinase activity, but also protein kinases in general. Therefore, analyses of Ph1-positive benign phase CML myeloid cells, the majority of which are well differentiated, could not be successfully performed. The inhibition of P210bcr-abl protein kinase activity is not a specific property of mature cells from CML patients since granulocytes from a normal volunteer also demonstrated a similar effect. However, extracts of Ph1-positive cultured B-lymphocytes from a patient in benign phase demonstrated active P210bcr-abl protein indicating that the P210bcr-abl protein is expressed in an enzymatically active form in the earlier phases of CML. In addition to the previously reported P210 and P190 abl-related proteins, a novel Mr 53,000 protein was found to undergo phosphorylation at serine and tyrosine in immune complex kinase assays of two blast crisis CML cell lines (K562 and EM2) and in samples from blast crisis patients in which P210bcr-abl was detected. Peptide mapping by the Cleveland technique suggested that Mr 53,000 protein is unrelated to P210bcr-abl. Immune complex kinase assays of K562 cells with an anti-src serum (GD-11) yielded active c-src kinase and a Mr 50,000 phosphorylated protein, both of which were resistant to alkaline hydrolysis. Peptide mapping suggested that Mr 53,000 protein is related to Mr 50,000 protein which is precipitated with P210bcr-abl as an Mr 300,000 protein complex.
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PMID:Analysis of P210bcr-abl tyrosine protein kinase activity in various subtypes of Philadelphia chromosome-positive cells from chronic myelogenous leukemia patients. 243 23

Phospholipid-sensitive Ca2+-dependent protein kinase (PL-Ca-PK) and its substrates were investigated in neutrophils from normal subjects and in chronic myelocytic and acute myelocytic leukemic cells from patients with or without treatment for leukemia. PL-Ca-PK and its substrates were found in total particulate fraction of normal neutrophils, but less in cytosol. In leukemic cells from chronic myelocytic leukemia patients without treatment, PL-Ca-PK and its substrate, Mr 38,000 protein, increased in cytosol but decreased in total particulate fraction as compared with normal neutrophils. In leukemic cells obtained from chronic myelocytic leukemia patients after treatment mainly with busulfan, PL-Ca-PK and Mr 38,000 protein were increased in total particulate fraction but decreased in cytosol. Using leukemic cells from acute myelocytic leukemia patients with or without treatment, similar results were obtained. The change of localization of PL-Ca-PK and Mr 38,000 protein in leukemic cells appeared to be correlated to the increase or decrease of the number of leukemic cells. These results suggested that PL-Ca-PK together with the substrate, Mr 38,000 protein, might be translocated from total particulate fraction to cytosol with the onset of leukemia, and from cytosol to total particulate fraction accompanying treatment for leukemia.
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PMID:Translocation of phospholipid-sensitive Ca2+-dependent protein kinase and its substrate, Mr 38,000 protein, in chronic myelocytic and acute myelocytic leukemias. 315 48

Protein kinase activities and cyclic AMP binding capacity were investigated in human peripheral blood cells from leukemic patients and normal controls. Using [gamma 32P] ATP as phosphoryldonor, the phosphorylating activities were not found to be significantly different in either normal or leukemic cells when measured on both artificial basic and acidic substrates. In contrast, the GTP-dependent casein kinase activity, CK2, which is almost undetectable in normal granulocytes, was markedly increased in highly proliferating myeloblastic cells from patients with acute myelogenous leukemia (AML) or with chronic myelogenous leukemia in blastic crisis (BC-CML). Levels of endogenous phosphotyrosine were not higher in leukemic cells than in normal peripheral lymphocytes or granulocytes. Finally, cAMP binding capacity was found to be increased in several types of proliferating leukemic cells, due to a higher amount of the R1-type regulatory subunit of the cAMP-dependent protein kinases. Specific patterns of cAMP binding proteins observed in the different types of normal blood cells were rather blurred in leukemic cells. In conclusion, modifications observed in human leukemic cells seem to be more related to proliferation or blockage in normal differentiation than to their cellular origin.
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PMID:Protein kinases in human leukemic cells. 386 3

Determination of levels and isozymic patterns of protein kinase activities was performed upon extracts from two human leukemia cell lines (K562 and HL-60) and blast cells from five untreated patients with acute myeloblastic leukemia and compared to activities from normal human peripheral blood granulocytes and bone marrow samples enriched for proliferative myeloid cells. The leukemic cells studied were found to have higher specific activities of cytosol cyclic adenosine 3':5'-monophosphate (cAMP)-independent casein kinase and lower activation by cAMP of their cytosol histone kinase compared to the normal myeloid cells studied. Diethylaminoethyl-cellulose chromatography revealed correspondingly higher amounts of cAMP-independent protein kinase isoenzymes (two casein kinase and one histone kinase peaks) in the leukemic cells, as well as altered ratios of the two cAMP-dependent isozymes. Casein phosphorylating activities extracted from the nuclei of the leukemic cell lines were also high compared to normal myeloid cells. Further purification and estimation of molecular weights of the isoenzymes present in leukemia were accomplished by gel filtration, using Sephacryl S-200. Resolution of the acute myeloblastic leukemia cell line nuclear casein kinase activity into two peaks was also thereby accomplished. The nuclear peaks eluted earlier than the corresponding cytoplasmic peaks; thus, the nuclear isoenzymes may not be identical to those from the cytoplasm. The increased protein kinase activity noted in such cells may be an important biochemical concomitant of transformation.
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PMID:Cyclic adenosine 3':5'-monophosphate-dependent and -independent protein kinase in acute myeloblastic leukemia. 626 62

The pattern of protein kinase activity in leukemic cells from patients with chronic myelocytic leukemia, acute myeloblastic leukemia, acute monocytic leukemia, chronic lymphocytic leukemia, and acute lymphoblastic leukemia was studied and compared with normal peripheral blood granulocytes and lymphocytes. Our data showed that: (a) histone kinase activity was slightly lower in leukemic cells than in normal cells, whereas casein kinase activity was 2- to 3-fold higher in leukemic cells; (b) cyclic adenosine 3':5'-monophosphate stimulated 1.4- to 1.6-fold histone kinase activity of both normal and leukemic cells, whereas it did not stimulate casein kinase activity; (c) the ratio of histone kinase activities to casein kinase activities correlated directly with the maturation of the white blood cells; and (d) histone and casein kinase activities of extracts from normal and leukemic cells behaved similarly on chromatography on phosphocellulose and casein/Sepharose 4B. These results suggest that the increase in casein kinase activity is not due to the appearance of a new type of casein kinase but to an increase of the casein kinases 1 and 2 present in normal cells.
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PMID:Cyclic adenosine 3':5'-monophosphate-dependent and -independent protein kinases in human leukemic cells. 629 19

The genome of the replication-defective avian myeloblastosis virus (AMV) contains an inserted cellular sequence (amv) that is part of the oncogene responsible for acute myeloblastic leukemia in chickens infected with AMV. Three antisera raised against distinct synthetic peptides predicted from the long open reading frame of amv specifically precipitated the same 48-kilodalton protein (p48amv) from leukemic myeloblasts but not from normal hematopoietic tissue, fibroblasts, or from fibroblasts infected with the AMV helper virus, MAV-1 (myeloblastosis-associated virus type 1). p48amv is not glycosylated or phosphorylated and does not appear to act as a protein kinase in vitro. The same three antisera that recognized p48amv also specifically precipitated a common 110-kilodalton protein from normal uninfected hematopoietic tissue. This normal cellular homologue of the AMV leukemogenic protein, p110proto-amv, was not present in normal fibroblasts, MAV-1 infected fibroblasts, or, interestingly, in some leukemic myeloblasts. We conclude that p48amv is the leukemogenic product of an altered, transduced, partial protooncogene. Short helper-virus sequences provide its carboxyl terminus and also may provide the amino terminus.
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PMID:Identification of the leukemogenic protein of avian myeloblastosis virus and of its normal cellular homologue. 630 85

The cyclin-dependent kinase inhibitors known as p15, p16 and p18 have been suggested as candidates for tumour suppressor genes. We examined these genes for their alterations in 46 myeloid leukaemias and 15 myeloid leukaemia cell lines. p16 mRNA expression was studied in 41 myeloid leukaemias. The p15 and p16 genes were either deleted or mutated in myeloid leukaemia lines at a high frequency [6/15 (40%) for p15; 8/15 (53%) for p16] but alterations in primary myeloid leukaemias are much less frequent [2/46 (4%) for p15; 3/46 (6%) for p16]. Alterations of p18 were not found in any of the samples. 13 primary myeloid leukaemia samples had negligible levels of p16 mRNA. In summary, the deletions of p15 and p16 genes identified in the myeloid leukaemia cell lines probably occurred during their in vitro immortalization. Alterations of the p16 or p15 gene only occurred in primary acute myeloid leukaemia samples that were of mixed myeloid/lymphoid lineage (CD19/CD20-positive acute myeloid leukaemia [AML], CD2/CD19-positive AML, and lymphoid blastic crisis of chronic myeloid leukaemia). Further studies are required to determine if the absence of mRNA expression results from inactivation of the p16 gene.
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PMID:Structural integrity of the cyclin-dependent kinase inhibitor genes, p15, p16 and p18 in myeloid leukaemias. 757 21

Recent evidence suggests that the human interferon-inducible double-stranded RNA-dependent protein kinase may function as a tumor suppressor. Here we describe the mapping of the gene for this kinase to chromosome region 2p21-22 by fluorescence in situ hybridization. A combined analysis of cytogenetic data from a series of 341 patients with hematologic disorders that exhibited cytogenetic abnormalities and from published reports indicates that abnormalities involving 2p21-22 occur nonrandomly and are observed among patients with acute myelogenous leukemia, raising the possibility of a role for this protein kinase in leukemogenesis.
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PMID:Mapping of the gene for interferon-inducible dsRNA-dependent protein kinase to chromosome region 2p21-22: a site of rearrangements in myeloproliferative disorders. 769 Nov 57

The chromosome band 9p21-22 is frequently rearranged or deleted in a variety of tumors including hematological malignancies. This supports the notion of a tumor suppressor gene in this chromosome region. Indeed, the p16/MTS1 gene encoding a cyclin-dependent kinase (CDK) inhibitor has been shown to be frequently deleted and/or inactivated by nonsense mutations in a number of tumors. We have examined 98 DNA samples from blood, bone marrow cells and lymph node biopsies of patients with leukemia (ALL and AML) or lymphoma (follicular lymphoma and T-cell lymphoma), using Southern blot hybridization and a p16/MTS1-specific probe. Molecular abnormalities, mainly homozygous deletions, were found principally in ALL (8 out of 22 patients), much less frequently in AML (2/32) and lymphoma (2/32). While these data argue in favor of a large involvement of p16/MTS1 in ALL, AML and lymphomas appear to be less frequently implicated.
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PMID:Alterations of the putative tumor suppressor gene p16/MTS1 in human hematological malignancies. 788 34


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