Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.5.4.4 (adenosine deaminase)
 5,136 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have analyzed the distribution and prognostic significance of terminal deoxynucleotidyl transferase (TdT) and adenosine deaminase (ADA) in connection with conventional cytology, cytogenetics, response to therapy, and survival. The study population consisted of 78 patients with AML, 44 patients with Ph1 + CML in chronic phase, and 35 adult patients with Ph1 + CML in blastic phase, among which 5 cases presented as Ph1 + acute leukemia. Nine percent of the AML cases were positive for TdT and were characterized by a high percentage of blast cells in bone marrow, myeloid features by cytochemistry and absence of the Philadelphia chromosome. The median ADA values of the TdT+ AML cases were several times higher than those obtained for the TdT- cases. The survival calculated for the two groups of AML cases subdivided according to ADA levels was significantly longer (p less than 0.025) for the patients with low levels of ADA (less than 250 U/10(8) cells). In chronic phase of CML, TdT was absent and ADA values were increased over normal controls only in cases with early signs of transformation. In blastic phase, 31% of the 35 cases were positive for TdT, and ADA values were significantly higher (p less than 0.001) in TdT+ than TdT- cases. The survival calculated from the onset of transformation was significantly longer for the TdT+ acute phase (10.4 mo) compared to the TdT- patients (4.8 mo; p less than 0.025). Four cases presenting as Ph1 + acute leukemia were TdT+ and had elevated levels of ADA; 3 of them responded to ALL therapy, reverting to a stable phase of CML.
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PMID:Prognostic significance of terminal transferase and adenosine deaminase in acute and chronic myeloid leukemia. 704 66

The use of polymers for delivering peptide and protein drugs is described. Soluble-polymer technology attempts to bind a polymer to all sites on therapeutic protein molecules that cause the body to recognize the molecules as foreign. Goals include a stable linkage, water solubility, low immunogenicity, prolonged half-life, and intact biological activity. Polyethylene glycol (PEG)-adenosine deaminase (ADA), or pegademase bovine, has FDA-approved labeling as replacement therapy for ADA deficiency in patients with severe combined immunodeficiency disease who are not suitable candidates for bone marrow transplantation. Pegademase bovine reverses the toxic accumulation of adenosine and deoxyadenosine in adenosine deaminase-deficient cells, restoring the immune system. PEG-asparaginase (pegaspargase) has shown promise in patients with acute lymphocytic leukemia; allergic reactions have been minimal. Animal studies suggest that superoxide dismutase has potential use in conditions in which the body's ability to remove oxygen free radicals is reduced, such as burns and myocardial infarction; coupling with PEG may greatly increase the protein's half-life. Other PEG-conjugated proteins under investigation include PEG-catalase, PEG-uricase, PEG-honeybee venom, PEG-hemoglobin, and PEG-modified ragweed pollen extract. Dextran, albumin, DL-amino acids, and polyvinyl pyrrolidone have also been studied as protein carriers; most of the products created thus far have not shown much promise. The coupling of polymers to proteins has yielded protein drugs with intact biological activity and reduced immunogenicity, but much remains to be learned about this technology.
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PMID:Polymers for delivering peptides and proteins. 816 Jun 72

Peripheral blood, bone marrow and/or lymph nodes of 77 patients with T- and B-ALLs/lymphomas were characterized for their surface membrane marker profiles using flow cytometry and fluorescence microscopy. Purine metabolism enzyme activities were compared with membrane immunophenotypes. T and B-ALLs/lymphomas subtypes were defined by the expression of surface membrane antigens detected by the monoclonal antibodies. Based on immunophenotyping we found the following characteristic marker profiles: in T-ALL-CD7, CD2, CD1, CD5, CD3, CD4, CD8, CD38, CD71; in T-NHL-CD7,CD2,CD3,CD4,CD5,CD6; in pre-B ALL-CD10, CD19, CD24, HLA-DR, CD34, in B-ALL-CD19, CD20, CD24, HLA-DR, SmIg with kappa or lamda light chains; in B-ALL-weak SmIg, kappa or lambda, CD19, CD20, CD24, CD5, HLA-DR; in B-NHL-CD19, CD20, CD22, CD24, CD5, more intensive SmIg, kappa or lambda. The cells of leukemic cases tended to have more immature phenotypes than those of lymphoma cases. Analysis of purine metabolism enzyme activities showed that there was a correlation between the values of adenosine deaminase (ADA) and purine nucleoside (PNP) and various types of T- and B-ALLs/lymphomas. ADA levels in B-NHL and B-CLL were lower than those in normal cells, while ADA level in T-ALL, T-NHL, pre-B-ALL and B-ALL was higher (the average 185,92,73,63 pkat. 10(-6)cells, respectively). ADA activity was significantly different between lymphocytes of control group and T-ALL(p<0.01), between T-ALL and T-NHL(p<0.05), between T-NHL and B-NHL(p<0.05) and between T-ALL and B-NHL(p<0.05). PNP activities were lower to those in normal cells. ADA/PNP ratio increased mostly in T-ALL, less in T-NHL, pre-B-ALL and B-ALL (10.8 and 5.3 and 2.2, and 2.0 respectively). ADA/PNP ratio was significantly different between T-ALL and pre-B-ALL(p<0.05) and between T-ALL and B-NHL(p<0.05).
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PMID:A comparison of some leucocyte differentiation markers and the adenosine deaminase and purine nucleoside phosphorylase values in B and T cell leukemias and lymphomas. 859 72

In 33 children, 23 with acute lymphoblastic leukemia (ALL) and 10 with solid tumors, the phenotype of the enzyme adenosine deaminase (ADA) was detected in the erythrocytes by electrophoresis in cellulose acetate. In all children the ADA enzyme activity was also determined in the plasma by spectrophotometry at the onset of the disease, during remission, at the end of the therapy, and during relapse. The phenotype in all children was ADA1-1. There was a difference in enzyme activity between the mean values of children with ALI and those with solid tumors. There were also differences among the subtypes of ALL and also among the stages of ALL and the stages of solid tumors. In 23 children with ALL the mean value (MV) and the corresponding standard error (SEM) of enzyme activity at the onset of the disease were MV +/- SEM = 60.2 +/- 6.2 IU/L. This was higher than that of the control group (control group: MV +/- SEM = 27.8 +/- 3.3 IU/L). During remission the enzyme activity was lower than that of the control group (MV +/- SEM = 19.6 +/- 1.7 IU/L); at the end of the therapy it was MV +/- SEM = 24.0 +/- 1.3 IU/L, which is close to that of the control group; and during relapse it was much higher compared with the control group (MV +/- SEM = 73.1 +/- 4.6 IU/L). These values are discussed in connection to the leukaemic subtypes. In 10 children with solid tumors the mean value of enzyme activity at the onset of the disease was MV +/- SEM = 48.8 +/- 2.4 IU/L. During therapy it was MV +/- SEM = 32.4 +/- 1.9 IU/L and at the end of therapy MV +/- SEM = 22.1 +/- 2.5 IU/L. The aim of this work is to study the qualitative isoenzyme abnormalities to better understand the biological nature of the malignancies, to distinguish main groups and subsets of ALL and solid tumors on an enzymatic basis, and to identify possible sensitive key enzymes as targets for chemotherapy.
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PMID:Prognostic significance of adenosine deaminase in children with malignancies. 883 33

Pentostatin (2prime prime or minute-deoxycoformycin, dCF) is a product of the fermentation of Streptomyces antibioticus. It is a tight-binding inhibitor of adenosine deaminase (ADA), an enzyme essential in cellular metabolism of purines. Children with congenital absence of ADA suffer from atrophy of lymphoid tissues and severe combined immune deficiency (SCID) syndrome. It was speculated that pentostatin would be lymphocytotoxic, and this proved to be the case, promoting its investigation in lymphoid neoplasms. It was anticipated that pentostatin would be most active in neoplasms with high intracellular concentrations of ADA---e.g., acute lymphocytic leukemia (ALL), particularly its T cell variety. Although pentostatin proved to be active in ALL, large doses were required and toxic effects outweighted therapeutic benefits. By contrast, pentostatin proved to be exceptionally active in hairy cell leukemia (HCL), a B cell neoplasm with low intracellular concentrations of ADA. Pentostatin has since been shown to possess activity in chronic lymphocytic leukemia, prolymphocytic leukemia, cutaneous T cell lymphomas, adult T cell lymphoma-leukemia, and low-grade non-Hodgkin's lymphomas. It potentiates the activity of vidarabine against viruses and against the cells of acute myeloid leukemia. Pentostatin is inactive in melanoma and renal carcinoma, but has not been adequately evaluated in other solid tumors. The toxic effects of pentostatin include renal failure, central nervous system (CNS) depression, immunosuppression, keratoconjunctivitis, and opportunistic infections. In the absence of pre-existing bone marrow compromise, pentostatin produces only mild myelosuppression. Aside from its use as an antineoplastic agent, pentostatin has potential applications as an immunosuppresive drug, as an antiviral agent, as an antimalarial compound, and in the protection of cells of the CNS from damage induced by ischemia and anoxia.
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PMID:Pentostatin (2prime prime or minute-Deoxycoformycin): Clinical Pharmacology, Role In Cancer Chemotherapy, and Future Prospects. 1184 52

Pentostatin (2'-deoxycoformycin, dCF) is a purine nucleoside analog and a product of the fermentation of Streptomyces antibioticus. It is a tight-binding inhibitor of adenosine deaminase (ADA), an enzyme essential in the cellular metabolism of purines. Children with congenital absence of ADA suffer from atrophy of lymphoid tissues and severe combined immune deficiency (SCID) syndrome. It was hypothesized that pentostatin would be lymphocytotoxic and this proved to be true; this finding prompted its investigation in lymphoid neoplasms. It was anticipated that pentostatin would be most active in neoplasms with high intracellular concentrations of ADA, e.g. acute lymphocytic leukemia (ALL), particularly of the T-cell variety. Although pentostatin proved to be active in ALL, large doses were required and major toxic effects outweighed therapeutic benefits. By contrast, pentostatin proved to be exceptionally active in hairy cell leukemia (HCL), a B-cell neoplasm with low intracellular concentrations of ADA. Pentostatin has since been shown to possess activity in chronic lymphocytic leukemia, prolymphocytic leukemia, cutaneous T-cell lymphomas, adult T-cell lymphoma-leukemia, and low grade non-Hodgkin's lymphomas. It potentiates the activity of vidarabine against viruses and against the cells of acute myeloid leukemia. Pentostatin is inactive in melanoma and renal carcinoma, but has not been adequately evaluated in other solid tumors. The toxic effects of pentostatin include renal failure, central nervous system (CNS) depression, immunosuppresion, keratoconjunctivitis, and opportunistic infections. In the absence of pre-existing bone marrow compromise, pentostatin produces only mild myelosuppression. Aside from its use as an antineoplastic agent, pentostatin has potential applications as an immunosuppressive drug, as an antiviral agent, as an antimalarial compound, and in the protection of cells of the CNS from damage induced by ischemia and anoxia. Clinical studies with pentostatin are ongoing, and its roles in the management of neoplastic and non-neoplastic diseases have yet to be fully defined.
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PMID:Deoxycoformycin (pentostatin): clinical pharmacology, role in the chemotherapy of cancer, and use in other diseases. 1465 Dec 24

We have investigated the mechanism of resistance of leukemia cells to Ara-C using an in-house cDNA microarray designed for the analysis of leukemia cells. We produced Ara-C-resistant cells from the CCRF-CEM (acute lymphoblastic leukemia) cell line and compared their gene-expression profile with that of wild-type cells. The adenosine deaminase (ADA) gene was highly up-regulated in Ara-C-resistant cells, while equilibrative nucleoside transporter 1 (ENT1) and several cell-cycle-related genes were down-regulated. Of all these genes, ENT1 seemed the most likely to be relevant to Ara-C resistance. To investigate the role of ENT1 in Ara-C-resistant cells, we transfected the cells with the gene. ENT1-transfected Ara-C-resistant cells resembled wild-type CCRF-CEM cells more closely than untransfected Ara-C-resistant cells in terms of growth rate, Ara-C-uptake characteristics, and ADA expression levels. The down-regulation of the ENT1 gene is expected to result in nucleotide deficiency in addition to blockage of Ara-C influx. Accordingly, Ara-C-resistant cells showed low growth rates, which were restored by transfection with ENT1. These low growth rates were also correlated with the phosphorylation level of cell-cycle checkpoint kinase 2. In this study we identified down-regulation of ENT1 as the factor responsible for Ara-C resistance, and this knowledge may be used to devise a clinical regimen that will overcome the resistance.
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PMID:Gene-expression profiling reveals down-regulation of equilibrative nucleoside transporter 1 (ENT1) in Ara-C-resistant CCRF-CEM-derived cells. 1563 14

The level of adenosine deaminase (ADA) and arylsulphatase A (ASA) in the sera of 22 patients with acute lymphoblastic leukemia (ALL) were significantly increased when compared with the control healthy group. Also, there is a significant increase in the activity of these enzymes in patients with ALL with central nervous system (CNS) infiltration when compared with patients of ALL without CNS infiltration. We conclude that the estimation of ADA and ASA in the serum may be useful for detection of the early infiltration of the central nervous system by leukemic cells in acute lymphoblastic leukemia.
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PMID:Serum adenosine deaminase and arylsulphatase A as an index of early infiltration of central nervous system in acute lymphoblastic leukemia. 1724 14

The posttranscriptional RNA editing by the type 1 adenosine deaminase acting on RNAs (ADAR1), expressed as p110 and p150 isoforms, is important for both physiological and pathological processes. Their expression and significance in leukemias remain unknown. Here, we investigated the expression of ADAR1 in Chinese pediatric acute leukemias by real-time PCR and Western blot. The results showed that significant high expression of p110 was detected in leukemias, especially in B-ALL, whereas a slight increase of p150 could be observed. Furthermore, the decrease of p110 expression was observed in B-ALL patients achieving complete remission. Moreover, among prognostic risk groups in ALL, the highest expressions of p110 and p150 were detected in standard-risk group, whereas their lowest expressions were in high-risk group. This observation was further confirmed in comparisons between good and poor prognostic groups based on prognostic related clinical features. These results demonstrated that ADAR1 isoforms showed different expression patterns, suggesting that they might play different roles in pediatric leukemias. Our results will help us for the better understanding of RNA editing, exploring the potential target for the treatment, and making prognostic evaluation in childhood leukemias.
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PMID:Abnormal expression of ADAR1 isoforms in Chinese pediatric acute leukemias. 2131 40

Gene therapy is emerging as a viable option for clinical therapy of monogenic disorders and other genetically defined diseases, with approved gene therapies available in Europe and newly approved gene therapies in the United States. In the past 10 years, gene therapy has moved from a distant possibility, even in the minds of much of the scientific community, to being widely realized as a valuable therapeutic tool with wide-ranging potential. The U.S. Food and Drug Administration has recently approved Luxturna (Spark Therapeutics Inc, Philadelphia, PA, USA), a recombinant adeno-associated virus (rAAV) 2 gene therapy for one type of Leber congenital amaurosis 2 ( 1 , 2 ). The European Medicines Agency (EMA) has approved 3 recombinant viral vector products: Glybera (UniQure, Amsterdam, The Netherlands), an rAAV vector for lipoprotein lipase deficiency; Strimvelis (Glaxo Smith-Kline, Brentford, United Kingdom), an ex vivo gammaretrovirus-based therapy for patients with adenosine deaminase-deficient severe combined immune deficiency (ADA-SCID); and Kymriah (Novartis, Basel, Switzerland), an ex vivo lentivirus-based therapy to engineer autologous chimeric antigen-receptor T (CAR-T) cells targeting CD19-positive cells in acute lymphoblastic leukemia. These examples will be followed by the clinical approval of other gene therapy products as this field matures. In this review we provide an overview of the state of gene therapy by discussing where the field stands with respect to the different gene therapy vector platforms and the types of therapies that are available.-Gruntman, A. M., Flotte, T. R. The rapidly evolving state of gene therapy.
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PMID:The rapidly evolving state of gene therapy. 3128 60


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