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)

The activity of metabolic enzymes, adenosine and thymidine, has been studied in the blood serum and lymphocytes of healthy people and oncological patients aged 23-80. An increase in the activity of thymidine kinase (EC 2.7.1.2), an enzyme of thymidine biosynthesis, was observed in the blood serum of oncological patients against a background of a sharp decrease in the activity of thymidine phosphorylase (EC 2.4.2.4), a catabolic enzyme. The revealed enzymic shifts have been observed in breast cancer patients after 36, in patients with the stomach cancer--after 46. It is found that an increase in the activity of adenosine deaminase (EC 3.5.4.4) and 5-nucleotidase of AMP (EC 3.1.3.5) in the blood serum of oncological patients is accompanied by a sharp decrease in the activity of these enzymes in lymphocytes.
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PMID:[Activity of adenosine and thymidine metabolism enzymes in the blood of cancer patients of various ages]. 233 24

The present study was undertaken to determine the adenosine deaminase (ADA) activity of peripheral lymphocytes in patients with gastric cancer, with respect to the cancer progression, the effect of surgery and/or immunotherapy. The gastric cancer patients showed lower lymphocyte ADA activity than did the normal control. The lymphocyte ADA activity did not decrease with the cancer progression. There was a significant correlation between lymphocyte ADA activity and blastogenesis of lymphocyte by phytohemaglutinin or concanavalin A. Six months following gastrectomy, the lymphocyte ADA activity was increased, as compared with the preoperative value. The ADA activity of patients on post-operative OK-432 showed a greater increase, as compared to that of patients not given this treatment. In conclusion, decreased lymphocyte ADA activity in gastric cancer patients might be due to either the cancer bearing status or to the immunological suppression.
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PMID:Alteration of adenosine deaminase levels in peripheral blood lymphocytes of patients with gastric cancer. 401 93

Adenosine deaminase activity, the key enzyme of adenosine inactivation, was studied in slices taken endoscopically from gastric cancer and macroscopically unchanged gastric mucosa surrounding the cancer. The activity of the enzyme was measured in mucosa homogenates by determination of ammonia liberated from substrate. It was found that adenosine deaminase activity in neoplastic lesions did not differ significantly from normal mucosa and that the gastric region studied (antrum, corpus) did not have an impact. A significant difference in enzyme activity was noticed between intestinal and diffuse-type gastric carcinoma (according to Lauren's classification); the intestinal type was characterized by lower adenosine deaminase activity than was the diffuse type. Since the activity of adenosine deaminase in gastric cancer did not exhibit significant differences from normal mucosa the diagnostic value of its determination is of less importance.
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PMID:Adenosine deaminase activity in gastric cancer. 803 75

Adenosine deaminase activity was studied in tissue slices taken endoscopically from gastric mucosa of patients with the intestinal type of gastric carcinoma. The enzyme activity was measured in mucosal homogenates by determination of ammonia liberated from substrate during 10-min incubation. It was found that: (1) the enzyme activity of de novo gastric cancer was significantly lower than that of recurrent cancer of the gastric remnant; and (2) the enzyme activity of uninvaded gastric mucosa surrounding the neoplastic lesion of non-operated stomach was significantly lower than of the gastric mucosa of partially resected stomach due to malignancy. Since the enzyme activity in gastric cancer and surrounding uninvaded gastric mucosa correlated well with the advance of neoplastic disease estimated by ultrasonography examination, we speculate that some systemic factors associated with tumor progression might be implicated in the regulation of adenosine deaminase activity.
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PMID:Adenosine deaminase activity in patients with the intestinal type of gastric carcinoma. 902 Sep 21

ADAR (adenosine deaminase acting on RNA) catalyzes the deamination of adenosine to generate inosine, through its binding to double-stranded RNA (dsRNA), a phenomenon known as RNA editing. One of the functions of ADAR1 is suppressing the type I interferon (IFN) response, but its mechanism in gastric cancer is not clearly understood. We analyzed changes in RNA editing and IFN signaling in ADAR1-depleted gastric cancer cells, to clarify how ADAR1 regulates IFN signaling. Interestingly, we observed a dramatic increase in the protein level of signal transducer and activator of transcription 1 (STAT1) and interferon regulatory factor 9 (IRF9) upon ADAR1 knockdown, in the absence of type I or type II IFN treatment. However, there were no changes in protein expression or localization of the mitochondrial antiviral signaling protein (MAVS) and interferon alpha and beta-receptor subunit 2 (IFNAR2), the two known mediators of IFN production. Instead, we found that miR-302a-3p binds to the untranslated region (UTR) of IRF9 and regulate its expression. The treatment of ADAR1-depleted AGS cells with an miR-302a mimic successfully restored IRF9 as well as STAT1 protein level. Hence, our results suggest that ADAR1 regulates IFN signaling in gastric cancer through the suppression of STAT1 and IRF9 via miR-302a, which is independent from the RNA editing of known IFN production pathway.
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PMID:ADAR1 Suppresses Interferon Signaling in Gastric Cancer Cells by MicroRNA-302a-Mediated IRF9/STAT1 Regulation. 3286 71