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)

2',5'-oligoadenylate synthetase (2-5OAS) has been studied in peripheral blood mononuclear cells from nine patients with hairy cell leukaemia (HCL) receiving therapy with the adenosine deaminase inhibitor deoxycoformycin (dCF) or alpha interferon (alpha-IFN). 2-5OAS mRNA was assayed by dot-blot hybridization. Increase of 2-5OAS mRNA level was seen in six patients with HCL treated with dCF and in one patient treated with alpha-IFN who responded to therapy. A patient with a variant form of HCL treated with dCF and the second patient treated with alpha-IFN did not show an increase of 2-5OAS mRNA and neither responded to therapy. The 15 other patients with T or B-chronic lymphoblastic leukaemia (CLL), T-acute lymphoblastic leukaemia (ALL), adult T-cell leukaemia lymphoma (ATLL), non-Hodgkins lymphoma (NHL), Sezary and T or B-prolymphocytic leukaemia (PLL) treated with dCF did not show an increase in 2-5OAS, though four patients, all with T-cell tumours, responded clinically. 2-5OAS activity is known to be stimulated by alpha-IFN and recent work suggests that this rise in 2-5OAS may result in increased cleavage of mRNA for tumour necrosis factor (TNF) and other cytokines on which autocrine growth and proliferation of the tumour cells are dependent. By analogy, we suggest that one mechanism of action of dCF in hairy cell leukaemia may be to break down an autocrine growth loop for TNF or other cytokines. An alternative explanation for these observations is that cytokines released from hairy cells in the bone marrow killed by dCF induce a rise in 2-5OAS in circulating leucocytes.
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PMID:Increase in 2',5'-oligoadenylate synthetase caused by deoxycoformycin in hairy cell leukaemia. 155 Jul 76

The activities of three purine pathway enzymes--adenosine deaminase (ADA), 5'-nucleotidase (5'N) and purine nucleoside phosphorylase (PNP)--were examined in the circulating malignant cells (Sezary cells) of eight patients with cutaneous T-cell lymphoma (CTCL). Cell lines derived from two other patients with CTCL were also studied. These were compared with enzyme activities in peripheral blood T-lymphocytes from 11 normal donors and six samples of human thymocytes. ADA activities were similar in the Sezary cells and peripheral blood T-cells (medians 7 U and 15 U, P = 0.14), and both of these groups demonstrated significantly lower activity than did the thymocytes (median 100 U, P = 0.002). 5'N activity in the Sezary cells was also similar to that of the T-lymphocytes (median 0.022 U and 0.030 U, P greater than 0.05) and both of these groups had significantly greater activity than did the thymocytes (median 0.002 U, P = 0.001). Median PNP activity in the Sezary cell population was also comparable to that measured in normal T-cells. These findings suggest there is a characteristic purine pathway enzyme pattern in Sezary cells that is similar to that seen in normal T-lymphocytes. This pattern is clearly distinguishable from that of thymocytes and from that previously described in lymphoblasts from patients with T-cell acute lymphoblastic leukaemia. These results support the concept that Sezary cells are well-differentiated with respect to the T-cell axis. Quantitation of purine pathway enzymes may be useful in defining subsets of T-cell malignancy.
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PMID:Purine pathway enzymes in the circulating malignant cells of patients with cutaneous T-cell lymphoma. 628 63