Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A review of the literature and current biochemical studies is presented which provides significant evidence of alteration in the level of the enzyme ribonuclease activity in cancer. Current studies reveal that 80% of all cancer patients have alteration in ribonuclease activity and that individuals known to be at high risk for the development of cancer also demonstrate significant alteration of ribonuclease activity. It is noted that while elevation of serum ribonuclease exists within the cancer state and appears to be independent of clinical status (relapse, remission, or cured), diminished activity is found within the tumor itself. Animal models are reviewed which demonstrate that ribonuclease activity becomes elevated in the murine species subsequent to the transplantation of tumor and following the infection of the host with oncogenic virus. The occurrence of elevated ribonuclease activity in high tumor incidence strain mice long before the development of overt tumor is alos discussed. To date it is not possible to assign a specific function to the changes in the level of ribonuclease in connection with the cancer state. However, evidence indicating that tumor chemotherapy is generally associated with early elevation of ribonuclease activity within the tumor cell suggests that increased ribonuclease activity may play a role in the process by which the host restricts neoplastic transformation. The potential of this enzyme as a biochemical marker in cancer is discussed.
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PMID:Alteration of human serum ribonuclease activity in malignancy. 75 46

An ovarian cystadenocarcinoma-associated antigen (OCAA) was found to be common to all serous and mucinous cystadenocarcinomas of the ovary. It was apparently absent in tissues of normal reproductive organs. Furthermore, OCAA was not detected in benign ovarian serous and mucinous cyst-adenomas or in any other gynecologic or nongynecologic cancers thus far tested. The antigenic determinant of OCAA was immunologically unrelated to the carcinoembryonic antigen, other known tumor antigens, or the histocompatibility antigens. We purified and partially characterized OCAA. The antigen was a high-molecular-weight glycoprotein soluble in 0.6 M perchloric acid. It consisted of about 50-60% protein (based on dry wt). Amino acid composition in OCAA was characterized by a high percentage of threonine, serine, proline, and valine. Galactose and N-acetylglucosamine were the principal carbohydrate constituents. The antigenic activity was resistant to treatment with trypsin and protease and also to treatment with DNase, RNase, and N-acetylneuraminidase. The antigenicity was considerably reduced by mild periodate oxidation.
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PMID:Tumor-associated antigen for cystadenocarcinomas of the ovary. 82 81

The antitumor effect of reserve polysaccharide, paramylon, from Euglena gracilis on the transplantable sarcoma-180 was examined in mice. This polysaccharide had an effect similar to that of lentinan. Paramylon, in a dose of 1 mug/g body weight, injected intraperitoneally 24 hr after tumor implantation had an inhibitory effect on the tumor growth, although without causing complete regression of the tumor. Alkaline-treated paramylon had a similar effect but at a smaller concentration than the native one. The inhibitory activity was not lost when the paramylon preparation was treated with pronase, DNase, or RNase. The antitumor effect might be a lymphocyte-mediated process. In tumors that were regressing after treatment, there was extensive outpouring of lymphoid cells with plasma cells and macrophages. A test conducted using paramylon ruled out the possibility of an interferon-mediated inhibiotry effect on tumor growth.
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PMID:Antitumor activity of paramylon on sarcoma-180 in mice. 82 42

Serum RNase levels were measured in 34 patients with multiple myeloma and compared with 51 normal controls and 28 non-myeloma patients on chronic hemodialysis. Nineteen of the myeloma patinets with creatinine clearance (CCr) greater than 50 ml/minute had mean serum RNase levels that were statistically indistinguishable from those of the normal controls. The 15 myeloma patinets with CCr less than 50 ml/minute had mean RNase levels much higher than normal controls or myeloma patients with normal renal function. Patients without myeloma but on hemodialysis for chronic renal failure of varied etiologies had markedly elevated serum RNase levels. A strong correlation between RNase levels and renal insufficiency, as measured by CCr, has thus been demonstrated. In addition, case histories of 5 representative myeloma patients were analyzed in greater detail; they illustrated the rise and fall of RNase levels as a function of the status of their renal insufficiency, regardless of the extent of the underlying myeloma. We concluded that the serum RNase level was an indicator of renal function, and was not a biomarker either for the presence or extent of the plasma cell tumor.
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PMID:Influence of renal insufficiency on levels of serum ribonuclease in patients with multiple myeloma. 84 91

We have investigated the pathogenesis of the polyclonal hypogammaglobulinemia associated with BALB/c plasmacytomas TEPC-183 and SPQC-11 to gain insight into the hypogammaglobulinemia observed in human myeloma. With pokeweed mitogen-driven IgM biosynthesis by mouse splenocytes as the indicator system for suppression, we found that a protein extract of asscites cells obtained from these tumor-bearing animals could suppress immunoglobulin production, whereas like extracts from a non-suppressing plasmacytoma, modified RPC-5, caused no suppression in vitro. Extracts of tumor ascites depleted of mononuclear phagocytes by iron carbonyl treatment showed little suppressor activity. The active extract was not cytotoxic and contained no mycoplasma or common murine viruses. Furthermore, the active suppressor factor appears to be a low m.w. protein that is not affected by treatment with ribonuclease. These results and others are consistent with the idea that the hypogammaglobulinemia of myeloma is due to the formation of immunoregulatory macrophage-like cells which synthesize a suppressor substance.
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PMID:Hypogammaglobulinemia in experimental myeloma: the role of suppressor factors from mononuclear phagocytes. 85 68

The ribonuclease activity of cerebrospinal fluid of 219 patients was studied. The normal level was 269 +/- 95 units/ml. Consistent elevations above 550 units/ml were found in: 1. Chronic cerebrovascular disease; 2. Spinal cord compression; 3. Tumors. The molecular weights of the ribonucleases in the cerebrospinal fluid are approximately 33,000; 21,000 and 15,000; the major species is the one with m.w. 33,000. Although the increase in the CSF ribonuclease activity is not disease specific, the measurement has provided corroborative help in cases when the CSF protein is normal. The increase in CSF RNAase is not due to red or white blood cells and the immunologic data suggest that the CSF enzyme activity is derived from the blood stream. Further studies are necessary to rule out a nerve cell origin of the CSF ribonuclease activity.
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PMID:Ribonuclease activity of human cerebrospinal fluid. 85 26

The cross-linked dimer of bovine pancreatic RNase (M.W. 28,000) is significantly more effective than the monomer in inhibiting tumor development in mice when administered i.p. 1 day after inoculation with sarcoma 180J ascites cells. Animals bearing solid tumors were not affected. In AKR/J mice with advanced leukemia, a single i.p. injection of 100 mug of the dimer led to about 50% reduction in the enlarged lymph nodes and the spleen at 24 hr. The half-life of the dimer in the bloodstream has been determined to be 10 min in rats and 6 min in mice, compared to values of 5 and 3.5 min, respectively, for the monomer. Analyses of the tissues of untreated leukemic mice for RNase and RNase inhibitors show that the tumor tissues are not deficient in RNase activity. Considerations of possible mechanisms of action of the dimer indicate that other basic proteins in this size range may merit examination as cytostatic agents toward transformed cells.
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PMID:Comparison of antitumor activities of pancreatic ribonuclease and its cross-linked dimer. 97 50

Fifty-one previously untreated cases of lung carcinoma and 7 normal healthy controls were evaluated with respect to serum ribonuclease (S-RNase) levels. Cellular immunity was tested in 22 of these 51 cases by leukocyte migration inhibition test (MIT) using extract of culture cell line of lung carcinoma. S-RNase levels in lung carcinomas were significantly elevated. There appeared to be no difference in S-RNase levels by histological classification. More striking was high S-RNase level in disseminated versus localized cases. MIT results indicated impairment of cellular immunity in those cases of more elevated S-RNase. S-RNase may be implicated in blocking phenomenon associated with neoplastic disease.
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PMID:Serum ribonuclease in patients with lung carcinoma. 99 11

Ehrlich ascites tumor cells were labeled with [5,6-3H]uridine in vivo during the exponential growth phase of the tumor in the mouse. Hydroxyapatite column chromatography of the total cell nucleic acid revealed a level of activity in the DNA approaching 50% of the incorporated activity of the RNA after 24 hours. After perchloric acid hydrolysis, the constituent bases of the DNA, separated by paper chromatography, contained more than 90% of the tritium radioactivity in the cytosine and thymine, at a ratio of approximately 2:1. Prior to digestion of the polymer, the level of label in the DNA was not sensitive to RNase, alkaline, or heat denaturation. Equilibrium density gradient centrifugation produced a single peak, coincidental for radioactivity and optical density at 260 nm. Our results indicate that tumor cells under replicative stress incorporated more than one-third of the tritium radioactivity of uridine into the DNA, whereas those at a growth plateau had less than 10% of the label in the DNA. This exogenous uridine radioactivity observed in the DNA represented neither a DNA-RNA hybrid, RNA primer pieces in DNA synthesis, nor any other RNase-sensitive species, but was apparently the consequence of amination and methylation of the tritium-labeled uracil moiety to satisfy the metabolic needs of the replicating cells for cytosine and thymine bases.
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PMID:Incorporation of tritiated uridine into DNA of Ehrlich ascites tumor cells. 100 13

Six transplantable murine tumor models were evaluated for changes in RNase activity. This study was conducted with spleen and thymus homogenates, as well as with plasma collected from tumor-bearing mice. Nuclease activity directed against the synthetic substrates, polyadenylic acid, polyuridylic acid, and polycytidylic acid, was measured and the data obtained for tumor-bearing animals were compared to their normal counterparts. Elevated activity against polyuridylic acid was observed in the plasma of all tumor-bearing mice. Although not as all inclusive, RNase levels in both the spleen and thymus were generally altered as well. The observance of unilateral changes in nuclease activity directed against the synthetic substrates demonstrated that, in most cases, two or more enzymes were being detected. The assay may have some eventual value in the monitoring of cancer
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PMID:Alterations in ribonuclease activities in the plasma, spleen, and thymus of tumor-bearing mice. 105 98


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