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

Clinical, pharmacologic, and immunologic effects of 2'-deoxycoformycin (dCF) were evaluated in 15 patients with advanced malignancies. Toxicity was less severe with a low dose (4 mg/m2) of dCF, but this dose still resulted in suppression of cellular adenosine deaminase activity, skin test reactivity, and lymphocyte responses to mitogens. Improvement in cutaneous T cell lymphoma plaques was seen after dCF. Further investigations of antitumor efficacy with the use of this low dosage schedule should continue in patients with hematologic neoplasms, and additional preliminary studies of the combination of an adenosine deaminase inhibitor with an adenosine analog should also be considered.
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PMID:Clinical, pharmacologic, and immunologic effects of 2'-deoxycoformycin. 326 48

2-Deoxycoformycin (DCF) was added to an intensive Pediatric Oncology Group protocol (#8303) for children with T-cell acute lymphoblastic leukemia or T-cell lymphoblastic lymphoma in first relapse. Twenty-seven patients received one or more courses of DCF at 15 mg/m2/day as a 3-day continuous infusion immediately after achieving a second remission with a four-drug reinduction regimen. Renal and neuromuscular toxicities were frequent and occasionally severe despite the provision of a source of adenosine deaminase by means of a packed red cell transfusion 1 day following the infusion of DCF. Hepatic toxicity, manifested by transaminase elevations, accompanied 62% of the courses. The median duration of the second complete remission was 4 months (range 2-16+ months), with only two of the 27 patients still in remission at 13+ and 16+ months. Plasma concentrations of deoxyadenosine (dAdo) and the ratio of red cell deoxyadenosine triphosphate to adenosine triphosphate (dATP:ATP) were measured prior to the DCF infusion and on day 4. A dATP:ATP ratio of 1.0 or greater was seen in two patients with acute renal failure. There was no apparent correlation between toxicity or response and the plasma dAdo concentrations. DCF administered according to this dose and schedule was excessively toxic and did not appreciably prolong the duration of the second complete remission in children with T-cell lymphoblastic malignancies.
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PMID:Deoxycoformycin treatment for childhood T-cell acute lymphoblastic leukemia early in second remission: a Pediatric Oncology Group Study. 326 63

In order to discriminate between malignant and benign effusions, the values of carcinoembryonic antigen (CEA), ferritin, beta2-microglobulin (BMG), acid-soluble glycoprotein (ASP), tissue polypeptide antigen (TPA), adenosine deaminase (ADA), and immunosuppressive acidic protein (IAP) were measured in the pleural fluid of 54 patients with lung cancer, 20 with malignancies other than lung cancer, 18 with tuberculous pleurisy, and 22 with benign diseases other than tuberculosis. CEA levels in malignant effusions were significantly higher than those in benign effusions. At a cutoff level of 5 ng/ml, 68% of the patients with lung cancer and 44% of the patients with other malignancies showed elevated pleural fluid CEA levels. In 13 lung cancer cases with negative pleural fluid cytology, nine cases had elevated pleural fluid CEA levels. The mean pleural fluid BMG level of patients with benign diseases was significantly higher than that of patients with malignant diseases, but there was a marked overlap between those with malignant and benign diseases. No significant differences were found in the pleural fluid ferritin, ASP, TPA, and IAP levels between malignant and benign conditions. ASP and IAP pleural fluid levels showed significant correlations with the pleural fluid C-reactive protein (CRP) concentrations suggesting that they also reflect inflammatory activity. The mean ADA activity in tuberculous effusion was significantly higher than that resulting from other causes of pleural effusion.
Cancer 1988 Jan 15
PMID:Tumor markers in pleural effusion diagnosis. 327 87

A new antimetabolite, 2'-deoxycoformycin (pentostatin), has striking antitumor activity in several lymphoid neoplasms. Isolated from cultured soil organisms, this purine analogue is a potent inhibitor of adenosine deaminase (ADA), and is thus selectively toxic to lymphocytes. Early clinical trials showed that high doses of pentostatin caused severe and unpredictable toxicity, but responses in refractory lymphoid malignancies were encouraging. Careful pharmacologic studies led to the definition of a safe and effective low weekly dose, at which protracted ADA inhibition occurs in neoplastic cells. The most sensitive tumor identified is hairy cell leukemia, in which durable remissions are achieved in more than 90% of patients with a relatively brief course of treatment. Other responsive diseases include chronic lymphocytic leukemia, prolymphocytic leukemia, mycosis fungoides, and acute T-cell lymphoma or leukemia. Response has been seen in acute lymphocytic leukemia, but the higher doses required are substantially more toxic. Pentostatin is valuable for treatment of indolent lymphoid malignancies and may be useful in non-cancer-related lymphocyte research.
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PMID:2'-Deoxycoformycin (pentostatin) for lymphoid malignancies. Rational development of an active new drug. 328 67

Laboratory and clinical data relating to the use of 2'-deoxycoformycin in human disease are reviewed. Pentostatin is an inhibitor of adenosine deaminase, an enzyme that is important for purine metabolism, but more than one mechanism may be involved in its cytotoxic action. Early studies with dCF employed large doses and for the most part were conducted in patients with acute lymphocytic leukaemia: responses were brief and relatively few, and severe renal, hepatic, and central nervous system toxicity were encountered, leading to temporary abandonment of clinical trials. More recently, it has been shown that dCF is effective in much smaller doses, with considerably less toxicity. It has proved to be more effective in low-grade lymphoid malignancies (chronic leukaemias, indolent lymphomas) than in more undifferentiated neoplasms (acute leukaemias, lymphoblastic and immunoblastic lymphomas), and is outstandingly effective in hairy cell leukaemia, both as initial therapy and after failure of splenectomy and interferon. Pentostatin is profoundly immunosuppressive: generally this is considered a disadvantage but its potential therapeutic exploitation merits investigation. Despite extensive knowledge of its biochemical effects, the optimal dose regimen of dCF and the value of combining it with purine antagonists remain to be defined.
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PMID:The role of pentostatin (2'-deoxycoformycin, dCF) in the management of lymphoproliferative malignancies. 333 90

Cancer incidence and mortality were analyzed in 1,181 blood relatives and 558 spouse controls in 24 families of severe combined immune deficiency (SCID) patients, to test the hypothesis that heterozygous carriers of a gene for an autosomal recessive form of SCID are predisposed to cancer. Since at least 1 patient in each family was female and there were no cases outside the probands' sibships, the pattern of occurrence of SCID within the families was compatible with autosomal recessive inheritance. The observed numbers of cancer cases and deaths did not exceed the expected numbers derived from population-based rates; and there was no cancer excess when incidence rates in blood relatives were compared directly to those in spouse controls, since the rate ratios were 1.2 and 1.0 for males and females, respectively. In addition, cancer rate ratios were not significantly elevated when calculated separately for the 9 families of adenosine deaminase (ADA)-deficient SCID patients and for the 15 families without evidence of ADA deficiency.
J Natl Cancer Inst 1987 Mar
PMID:Cancer in families with severe combined immune deficiency. 346 59

Resting peripheral blood lymphocytes have a large number of single strand breaks and are especially sensitive to DNA damaging agents. Deoxyadenosine, an adenosine deaminase substrate, in combination with the adenosine deaminase inhibitor deoxycoformycin, causes accumulation of single strand breaks in resting peripheral blood lymphocytes. The induction of single strand breaks by deoxyadenosine is the result of the accumulation of large amounts of intracellular dATP, which creates imbalance in deoxynucleoside triphosphate levels. This imbalance in deoxynucleoside triphosphate levels interferes with the repair of single strand breaks in deoxyadenosine treated cells. Deoxyadenosine acts synergistically with N-methyl-N'-nitro-N-nitrosoguanidine, a DNA alkylating agent, by inhibiting the repair of N-methyl-N'-nitro-N-nitrosoguanidine-induced single strand breaks. We propose that the increased sensitivity of resting peripheral blood lymphocytes to deoxyadenosine and possibly to other DNA damaging agents may be associated with impaired DNA repair ability due to imbalance in intracellular levels of deoxynucleoside triphosphate.
Cancer Res 1986 Apr
PMID:DNA repair in nondividing human lymphocytes: inhibition by deoxyadenosine. 348 13

The rate of nucleoside transport decreased profoundly in human promyelocytic leukemia HL-60 cells after myeloid differentiation was induced by 5-6 days of exposure to 0.8% N,N-dimethylformamide (DMF). The facilitated diffusion of 100 microM radiolabeled adenosine and 2'-deoxyadenosine, measured by rapid transport assays, decreased 10- to 20-fold. The transport of 2 microM coformycin or 2'-deoxycoformycin, which is mediated by the same mechanism and was monitored by the adenosine deaminase titration assay, decreased 29-fold. The reduction in nucleoside transport capacity after DMF treatment was confirmed by a 19-fold decrease in the number of specific binding sites per cell (from 24-30 X 10(4) to 1.2-1.7 X 10(4)) for [3H]-6-p-nitrobenzylthioinosine, a nucleoside transport inhibitor. The binding affinity of 6-p-nitrobenzylthioinosine was not altered significantly and nucleoside transport remained sensitive to the transport inhibitors, 6-p-nitrobenzylthioinosine, dipyridamole, and dilazep after DMF-induced maturation. Time-dependence studies showed that the rate of 100 microM deoxyadenosine transport was unchanged for the first 24 h of exposure to DMF but fell to about 36% of control rates at 24-26 h and then gradually decreased further to about 4-5% of control rates after 5-6 days. In contrast, transport rates of the purine bases were reduced only 2- to 3-fold in HL-60 cells after 5 days of DMF treatment. The rates of adenosine and deoxyadenosine transport were unchanged or reduced by no more than 2-fold after 5-6 days of exposure to 0.8% DMF in the following human tumor cell lines that are not inducible with DMF: ARH-77 (multiple myeloma), KG-1 (acute myelogenous), and K-562 (chronic myelogenous). Thus, changes in nucleoside transport may serve as an early, membrane-associated marker of differentiation of the HL-60 cell line.
Cancer Res 1986 Jul
PMID:Changes in nucleoside transport of HL-60 human promyelocytic cells during N,N-dimethylformamide induced differentiation. 348 11

Pentostatin (dCF), an inhibitor of adenosine deaminase, has shown activity in the treatment of several lymphoid malignancies, even in the earliest phase I trials. An analysis of the first 300 patients treated in such trials shows a high incidence of severe infection (8%) during the relatively brief period of treatment. Of 24 patients in whom infection was diagnosed, 17 had no evidence of myelosuppression. The causative organisms included viruses, fungi, and bacteria of both high and low pathogenicity. Two-thirds of the infections were fatal. It is suggested that dCF may cause a syndrome similar to severe combined immunodeficiency during the course of treatment. Patients treated with dCF who show evidence of infection, even in the absence of neutropenia, should receive vigorous and rapid diagnostic evaluation to establish the cause of their infection, and aggressive treatment of suspected organisms.
Cancer Treat Rep 1986 Sep
PMID:Association of severe and fatal infections and treatment with pentostatin. 348 5

Four patients with refractory chronic lymphocytic leukemia were treated with the adenosine deaminase inhibitor, 2'-deoxycoformycin, and initially received 4 mg/m2 i.v. weekly. Clinical responses to therapy varied: Patient A had a minimal response; whereas Patient D showed an 85% decrease in lymphocyte count at 2 wk; and Patients B and C had intermediate responses. The pretreatment mononuclear cell adenosine deaminase activities, which ranged from 1.6 to 44.6 nmol adenosine/h/10(6) cells, decreased to approximately 1 nmol adenosine /h/10(6) cells 24 h following 2'-deoxycoformycin, and increased to 15 to 50% of the pretreatment activity prior to the second drug treatment. The clinical response to 2'-deoxycoformycin was unrelated to the pre- or posttreatment adenosine deaminase activities or to the rate of return of enzyme activities following treatment. The plasma deoxyadenosine levels and the leukemic cell dATP concentrations rose slightly with therapy, but there was no correlation between the magnitude of increase and clinical response. No significant levels of DNA strand breaks were observed in the leukemic cells following treatment, although the NAD levels decreased slightly in two patients. When peripheral mononuclear cells from the patients and two controls were incubated in vitro for 24 h with 2'-deoxycoformycin and increasing concentrations of deoxyadenosine, a concentration-dependent increase in dATP and decrease in NAD were observed in both the patients and normals. The normal cells, and cells from two patients, developed a significant number of DNA strand breaks. However, there was no relationship between the formation of DNA breaks and the degree of accumulation of dATP or depletion of NAD, or between any of these changes and subsequent clinical responses to 2'-deoxycoformycin. Based on this study, it appears that the antitumor activity of 2'-deoxycoformycin in chronic lymphocytic leukemia is unrelated to the induction of DNA strand breaks or to changes in the levels of dATP or NAD in the leukemic cells.
Cancer Res 1987 May 01
PMID:Induction of DNA strand breaks in chronic lymphocytic leukemia following treatment with 2'-deoxycoformycin in vivo and in vitro. 349 9


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