Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.3.5 (5'-nucleotidase)
3,167 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The existence of a sarcoma derived from the antigen-presenting follicular dendritic cells (FDCs) has been assumed but never confirmed. This report describes a tumor from axillary lymph nodes of a 39-year-old male in which the morphologic, enzyme histochemical, and immune phenotypic data are consistent with the malignant cells being of FDC origin. Morphologically, the tumor showed a tendency toward bi- and polynucleation with areas of storiform growth pattern, resulting in an initial diagnosis of malignant fibrous histiocytoma. However, the tumor cells had interconnections with well-developed desmosomes. Enzyme histochemistry revealed strong 5'-nucleotidase activity. Immunohistologic analysis showed that tumor cells expressed two of three FDC-specific antigens (Ki-M4, BU-10, and R4/23) strongly. Virtually all myelomonocytic markers were absent. Like normal FDCs, the leukocyte antigens CD35, CD19, CD21, and CD23 were expressed strongly and CD4 antigen weakly. No staining was evident for CD45 antigen, and no nonhemopoietic cell markers were expressed. The origin of the normal FDC is obscure. Given some evidence suggesting a bone marrow origin for the FDC, this cell may represent a lineage distinct from other known cell lineages derived from bone marrow stem cells since its immune phenotype differs considerably from them.
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PMID:Immunophenotypic analysis of neoplastic cells in follicular dendritic cell sarcoma. 331 45

Telangiectatic osteosarcoma (TOS) which occurred in the metaphysis of the right femoral bone in a 13-year-old female was reported. It showed osteolytic and cystic lesion without sclerotic change on roentgenogram and consisted histologically of various sized blood-filled spaces lined by layers of round to oval tumor cells in the thin fibrous septa. In some solid areas, a proliferation of atypical tumor cells with large prominent nucleoli was evident, embedded in the lace-like osteoid tissue. Mitotic cells were easily encountered. A large population of tumor cells revealed high alkaline phosphatase activity as well as 5'-nucleotidase activity, indicative of osteogenic cell origin. Ultrastructurally, they showed osteogenic characteristics of well-developed rough endoplasmic reticula, cytoplasmic microfibrils, and dense bodies, but not for those of endothelial cells. In this report, we suggest that alkaline phosphatase activity in biopsy and surgical specimens is useful for distinguishing TOS from other osteolytic bone tumors, with regard to its ontogenic discussion.
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PMID:High alkaline phosphatase activity of telangiectatic osteosarcoma (TOS) and its diagnostic significance. 347 63

The importance of estrogens in the dietary lipid alteration of R3230AC mammary carcinoma growth and insulin binding was studied. Animals were divided into three groups [intact, ovariectomized, and ovariectomized treated with estradiol valerate (EV)] and were fed diets containing either 0% fat (fat free), 0.5% corn oil (low fat), or 20% corn oil (high fat). An alteration of tumor burden between animals fed high-fat versus either low-fat or fat-free diets was observed and appeared to be influenced by the estrogen status of the animal. The difference in tumor burden attributed to dietary lipid seen in intact rats was less in ovariectomized rats and greater in ovariectomized rats treated with EV, despite the fact that absolute tumor burden was reduced by this treatment. A similar relationship was observed for dietary lipid-induced differences in insulin binding to plasma membranes from these tumors. Reduction of tumor growth resulting from estrogen treatment was greater in low-fat- and fat-free-fed animals than in high-fat-fed rats. Again, tumor growth behavior appeared to be related to the reduction of insulin binding induced by estrogen treatment; insulin binding to plasma membranes from animals fed a low unsaturated lipid diet was decreased to a greater extent by EV treatment than in membranes from high-fat-fed rats. Altered tumor growth and membrane insulin binding, resulting from dietary perturbations and/or EV treatment, were not invariably related to serum insulin levels, nor to differences in membrane preparation, as reflected by 5'-nucleotidase activity, nor to membrane fatty acid composition or uptake of proline. Taken together, these results suggest a potential role of estrogens and insulin receptors as mediators of the dietary lipid alterations of growth of the R3230AC mammary carcinoma.
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PMID:A role of estrogens and insulin binding in the dietary lipid alteration of R3230AC mammary carcinoma growth in rats. 388 27

The "biliary tract" enzymes (leucine aminopeptidase, gamma-glutamyltranspeptidase and 5'-nucleotidase) in serum reflect to varying degrees, obstruction, proliferation, inflammation and neoplasia involving the hepatobiliary duct system. Their use is directed towards two purposes: (1) as non-electrophoretic assays to evaluate the source of an elevated non-specific alkaline phosphatase and (2) to offer greater sensitivity and specificity for space-occuping lesions in the liver. In appropriate clinical states, any of the three enzymes offer these advantages and there is little to chose among them. Selection of the assay to use in the clinical laboratory then becomes based on non-clinical factors, i.e., technical ease, apparent substrate specifities, etc. With these additional factors and despite some shortcomings, our selection is leucine aminopeptidase.
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PMID:The enzymes of the hepatobiliary tract: a biochemical and clinical comparison. 415 29

The purpose of this study was to determine if there is a difference in the biochemical composition of the edge of a tumor and the center of a tumor. There was a greater concentration of histamine in the edge (mean +/- SEM, 9.3 +/- 1.2 pmole/mg of wet weight) than in the center (3.6 +/- 0.4 pmole/mg of wet weight) of a transplantable golden hamster insulinoma. There was, however, no difference in the concentration of norepinephrine, protein, DNA, or phosphate, or in the activity of the enzymes, monoamine oxidase, catechol-O-methyltransferase, L-dopa decarboxylase, or 5'-nucleotidase in the edge or in the center of the tumor. Using chemical analysis and autoradiography, there was a comparable incorporation of tritiated thymidine in the edge and in the center of the tumor.
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PMID:Biochemical composition of edge and center of malignant hamster insulinoma. 609 91

Purified plasma membranes were obtained from five transplantable human tumors, a grade IV astrocytoma, an oat cell carcinoma, and three melanomas. Plasma membrane fractions were isolated from tumor homogenates by differential and discontinuous sucrose gradient centrifugation. Determination of enzyme activities indicated that the plasma membranes were enriched 10- to 20-fold with respect to 5'-nucleotidase, nicotinamide adenine dinucleotide glycohydrolase, Mg2+-activated nucleoside triphosphatase, and sialic acid. Specific activities of nearly all the enzymes varied with the individual tumors, even among tumors of the same type, i.e., the melanomas. Electron micrographs of the plasma membrane fractions showed smooth single-membrane vesicles with slight contamination by lysosomes. Therefore, these membranes are suitable for comparative biochemical studies and for the preparation of tumor-specific monoclonal antibodies. Plasma membranes from all five tumors contained very high Mg2+-adenosine triphosphatase (ATPase) activities. The Na+-K+-ATPase was a minor component of the total ATPase of these membranes (less than 30%). The major component was an ATPase exhibiting similar activity toward several nucleoside triphosphates. The activity of such a nucleoside triphosphatase has been correlated with tumorigenicity in cultured liver epithelial cells. The nucleoside triphosphatase of the plasma membranes of astrocytoma and oat cell carcinoma was stimulated from 50 to 1005 by concanavalin A, whereas ATPase of the melanoma plasma membranes was not or only slightly stimulated. The different response to concanavalin A could be due to differences in the ATPase molecules of the individual tumors or to the different environment of the ATPase.
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PMID:Isolation and characterization of plasma membranes from transplantable human astrocytoma, oat cell carcinoma, and melanomas. 611 38

Liver metastases due to the more common neoplastic diseases such as colorectal, breast, or bronchogenic carcinoma are a frequent occurrence and are associated with an ominous prognosis. Earlier detection followed by appropriate therapeutic interventions might have a decided effect on the subsequent course of disease. Controversy exists over the selection of tests with the greatest sensitivity, specificity, and potential utility. Preliminary evidence suggest that gamma-glutamyl transpeptidase and 5'-nucleotidase may be of particular significance. Four enzymes--gamma-glutamyl transpeptidase, 5'-nucleotidase, leucine aminopeptidase, and alkaline phosphatase plus carcinoembryonic antigen--were compared in the same blood samples from selected patients with breast and small cell carcinoma of the lung. Gamma-Glutamyl transpeptidase was the most sensitive test with 28/29 (97%) patients with hepatic metastases having elevated enzymatic activity in their sera. For patients with small cell carcinoma of the lung followed serially, gamma-glutamyl transpeptidase activity was increased an average of 5 months before liver metastases were detected by clinical means. Two factors are important in the interpretation of the results of gamma-glutamyl transpeptidase analysis: (1) Hepatic dysfunction due to diseases other than metastatic tumor involvement can cause a rise in enzyme levels as can (2) medications or ethanol which activate the hepatic microsomal drug metabolizing system. Of particular importance, however, is the fact that antitumor chemotherapy, even intensive and multiple agent, did not appear to effect the enzyme activity in the sera of patients with breast or small cell carcinoma of the lung. Gamma-glutamyl transpeptidase in combination with carcinoembryonic antigen may be of particular value in detecting liver metastases and in assessing subsequent response to therapy.
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PMID:Biological markers as an aid in the clinical management of patients with liver metastases. 612 62

Crude tissue or tumor extracts either do not contain sufficient inosine 5'-monophosphate dehydrogenase (IMPD) activity to be measured spectrophotometrically, or interfering enzyme activities prevent the use of a more sensitive radiochemical assay. A modified assay system which incorporates alpha, beta-methylene adenosine 5'-diphosphate, an inhibitor of 5'-nucleotidase; allopurinol, an inhibitor of xanthine oxidase; and ethylenediaminetetraacetate, an inhibitor of alkaline phosphatase, has been developed. [14C]Xanthine monophosphate produced during the assay was separated from [14C]hypoxanthine monophosphate by thin-layer chromatography on flexible diethylaminoethyl-cellulose sheets. Xanthine monophosphate formation was linear for at least 40 min and was inhibited by greater than 95% in the presence of mycophenolic acid, a specific IMPD inhibitor. Partial purified IMPD from murine EMT6 tumors was used to compare assay rates obtained with the radiochemical and spectrophotometric assays under identical conditions. The reaction rate of the radiochemical assay was 0.92 +/- 0.07 (S.E.) of the rate of xanthine monophosphate formation as determined spectrophotometrically at 290 nm, indicating that both assays are measuring product formation with an equal degree of accuracy. The improved radiochemical assay was used to determine IMPD specific activity in supernatants from EMT6 tumors and several normal mouse tissues. The observed activities (nmol/min/mg protein) were: EMT6 tumor, 0.303; spleen, 0.029; brain, 0.022; kidney, 0.015; lung, 0.009; liver, 0.008; and heart and skeletal muscle, less than 0.004.
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PMID:Sensitive radiochemical assay for inosine 5'-monophosphate dehydrogenase and determination of activity in murine tumor and tissue extracts. 613 40

The effects of a chronic 8- to 12-week administration of the hepatic tumor promoter, phenobarbital, on further altering the biochemical enzyme deviation patterns shown by hyperplastic liver nodules was examined in rats previously subjected to the initiation/selection protocol of Solt and Farber. Hyperplastic liver nodules of various size classes from the phenobarbital-treated group exhibited a significant increase in GGT specific activity, as well as 2- to 3-fold higher levels of microsomal cytochrome P-450 than was shown by control nodules. The increase in GGT specific activity was also found in many cases to be higher in those hyperplastic liver nodules from the phenobarbital-treated group with diameters greater than 3.0-3.5 mm than in nodules of a smaller size. In contrast, the GGT specific activity of the control nodules did not correlate with differences in their sizes. Furthermore, while histochemical staining of GGT activity appeared uniform in sections of the various sized hyperplastic nodules from the phenobarbital-treated group, biochemical measurements indicated a consistently higher specific activity for this enzyme in tissue taken from the central portion of the nodule than in tissue from the peripheral portion of the nodule. On the other hand, the specific activities of glucose-6-phosphatase, 5'-nucleotidase, and fructose-1,6-diphosphate aldolase of the hyperplastic liver nodules were not found to be significantly altered over control values by the chronic phenobarbital treatment, suggesting a stability of these other marker enzyme alterations during the early promotional phase of hepatocarcinogenesis.
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PMID:Effect of phenobarbital on the altered biochemical phenotypes expressed by hyperplastic liver nodules during hepatocarcinogenesis in the rat. 614 62

At a nontoxic dose (50 microM), the two potent uridine phosphorylase inhibitors, benzylacyclouridine and benzyloxybenzylacyclouridine (BBAU), potentiated 5-fluoro-2'-deoxyuridine (FdUrd) growth inhibition of human pancreatic carcinoma (DAN) and, to a lesser extent, human lung carcinoma (LX-1) cells in culture. BBAU was more effective than benzylacyclouridine. BBAU (50 microM) enhanced the cytocidal effect of FdUrd (1 microM, 3 hr) on DAN grown on soft agar from 75 to 88%. In antithymocyte serum-immunosuppressed mice bearing DAN, the mean tumor weight in animals treated with FdUrd (50 mg/kg/day for 2 days) was 11% less than that of untreated controls. When BBAU (10 mg/kg/day for 2 days) was coadministered, the mean tumor weight at Day 10 was 78% less than untreated controls, with no apparent host toxicity, clearly demonstrating the potentiation of the antitumor effects of FdUrd by BBAU. The fact that DAN responded better than LX-1 to benzylacyclouridine and BBAU could be due, in part, to the lower relative activity of thymidine phosphorylase to uridine phosphorylase in DAN compared to LX-1. The activities of other enzymes involved in FdUrd metabolism, thymidine kinase, uridine kinase, orotate phosphoribosyltransferase, 5'-nucleotidase, and dihydrouracil dehydrogenase, did not differ between the two cell lines.
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PMID:Potentiation of 5-fluoro-2'-deoxyuridine antineoplastic activity by the uridine phosphorylase inhibitors benzylacyclouridine and benzyloxybenzylacyclouridine. 623 86


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