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)

To demonstrate the presence of specific antigens in the normal and malignant gastric juice the immunological and chemical features of certain antigens with glycoprotein structure from malignant gastric jucice and gastric tumors were studied comparatively with those of antigens obtained from normal gastric juice and gastric tissue. The investigation was carried out in tumor tissue extracts from 7 patients with malignant gastric tumors and in gastric juice from 45 patients with other non-cancerous diseases. From the five fractions obtained, which gave immunoelectrophoretic precipitin lines in the beta and alpha-globulin regions with the antiserum against total normal gastric juice, a single specific was separated by means of successive chromatographies on sephadex G--100 and DEAE-Sephadex -a--50 (eluted in NaCl concentration gradient). This fraction represented 11.1 per cent of the total proteins. None of the five fractions could be identified with carcinoembryonic antigen (value in gastric juice and gastric malignant tumors = 2 to 10 ng per mg lyophilized products).
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PMID:Antigens with glycoprotein structure in the gastric juice. I. Immunological and chemical determinations. 63 6

Glycoprotein synthesis and secretion were measured in short-term organ culture of normal and neoplastic colonic mucosa from 11 patients undergoing colectomy for colon cancer. Mucosal explants were incubated for up to 24 hr with [3H]glucosamine, which was incorporated into both explant and secreted glycoproteins. Structural and functional viability was documented by morphological studies that showed excellent preservation of architectural detail and biochemical studies that documented a steady increase in glycoprotein synthesis during 24-hr incubation. The major difference between normal and neoplastic mucosa was a 35% decrease (p less than 0.02) in the incorporation of [3H]glucosamine into tumor explants, as compared to the amount incorporated into normal explants from the same patient. The rate of secretion of radiolabeled glycoproteins into the medium did not differ significantly. Separation of explants into particulate and cytosol fractions showed that the overall decreases in glycoprotein synthesis in tumor explants was primarily due to a marked reduction in particulate glycoprotein synthesis in the cancer tissue.
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PMID:Glycoprotein synthesis and secretion in human colon cancers and normal colonic mucosa. 67 85

B16 melanoma cells were treated in vitro with muconomycin A, a long-lasting inhibitor of protein and glycoprotein synthesis, to reduce cellular sialic acid. Two i.p. inoculations of 10(7) muconomycin-treated cells into female C57BL/6 mice, followed by challenge with homologous live cells, resulted in a significant decrease in tumor incidence when compared to the results of inoculation with untreated cells (p less than 0.01). Inoculation of mice with cells treated with neuraminidase resulted in little or no decrease in tumor incidence. Effective immunity was dependent on the number of cells injected and was found only with the i.p. route of inoculation into female mice.
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PMID:Increased tumor immunity in mice inoculated with muconomycin A-treated B16 melanoma cells. 69 27

Serial serum protein determinations and immunological monitoring were performed prior to and following a single 4 to 5 liter plasma exchange in 10 patients with disseminated cancer. The most consistent changes were observed for two initially elevated alpha globulins, acid glycoprotein and haptoglobin, which declined rapidly in all patients 1 hour after plasmapheresis and began to rise again as early as 24 hours post-plasmapheresis to reach initial levels by 72 hours. Among the immunological parameters T and B cell counts, and phytohemaglutinin-induced lymphocyte transformation showed little change. In 4 out of 10 patients C3 levels dropped at 1 hour post-plasmapheresis and continued to decline to 24 hours, suggesting that consumption of C3 possibly by macrophages may have occurred. In view of our earlier reports that repeated plasmapheresis induced partial tumor regressions in patients with disseminated cancer and that these regressions may have been related to depletion of immunosuppressive serum proteins, it is suggested that to maintain levels of these rapidly renewed proteins at a minimum for as long as possible, it is most appropriate to perform plasmapheresis every 48 hours rather than every 72 or 96 hours as was the case in the earlier study.
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PMID:Immunological and plasma protein changes in cancer patients following a single plasmapheresis. 74 56

Primary cultures from three serially transplanted mouse pituitary thyrotropic tumors, Furth 97A, 97B, and 97C, and one newly generated tumor, NIH 101A, were shown to secrete free alpha subunits and a beta subunit (TSH-beta) in addition to intact TSH. The three glycopeptides were measured in specific, heterologous radioimmunoassays. Basal secretion of alpha subunit was found to be in excess in all four thyrotropic tumor cultures, ranging from 5.7- to 8.9-fold higher than that of intact TSH and 30- to 35-fold higher than that of free TSH-beta. In cultures from 97A, TRH (10(-7) M) stimulated the secretion of TSH, alpha subunit, and TSH-beta by 175-185% and (T4, 10(-5) M) inhibited TSH to 19%, alpha subunit to 68%, and TSH-beta to 58% of control. Secretion of TSH and its subunits in cultures from 97B was not consistently affected by TRH or T4. In cultures from 97C, TSH and alpha secretion was inhibited in a dose-dependent fashion by T3 from 2.5 x10(-9) to 1.6x10(-7) M. Gel chromatography of incubation media from tumor 97A revealed elution volumes of TSH and alpha similar to those of purified rat glycopeptides and confirmed the excess secretion of free alpha subunit. In contrast, the alpha to TSH ratios in media from cultures of pituitary cells from normal and thyroidectomized rats were 1.6 and 0.8, respectively. The total production of TSH and its subunits was measured in cultures from tumor 97A and confirmed that alpha subunit was synthesized excessively. The ratio of the plasma concentrations of alpha to TSH in tumor-bearing mice was 1.6 compared to 1.3 in thyroidectomized mice, and 0.36 in thyroidectomized rats. The alpha to TSH ratios in extracts of the corresponding thyrotropic tissues (tumor or pituitary) were 2.7, 1.7, and 0.40, respectively. These data are analogous to those reported in humans with thyrotropic and certain other pituitary tumors, and support hypothesis that the subunits of glycoprotein hormones are independently synthesized.
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PMID:Excess production of free alpha subunits by mouse pituitary thyrotropic tumor cells in vitro. 74 72

Gastric juice was neutralized (nGJ) in vivo by 80 ml of a phosphate buffer containing radiolabelled vitamin B12 as dilution indicator. Unprocessed nGJ was analyzed in the double gel diffusion technique for the presence of serum proteins using monospecific antisera. Alpha1-Acid glycoprotein (AGP) was found in a high incidence (36 out of 38 subjects) in nGJ of gastric cancer patients. AGP was also observed less frequently in nGJ of patients with Billroth II resections (6/15), metaplasia (11/52), gastric ulcer (3/24), chronic atrophic gastritis (2/26) and chronic gastritis (3/63). AGP was absent in the control group (0/21), in patients with surface gastritis (0/38) and in subjects with normal acid secretion (0/45). Immunochemical studies demonstrated no identity of AGP with human "gastrointestinal tumor associated antigens." In 7 out of 17 AGP positive samples immunochemical differences between gastric and serum AGP were observed.
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PMID:Alpha 1-acid glycoprotein in gastric cancer juice. 80 43

Precipitation tests using properly absorbed rabbit antisera revealed that PCA extracts of DMH-induced rat jejunal and colonic adenocarcinomas contain an antigen that is not detectable in extracts of normal rat tissue or other rat tumors. This rat tumor antigen was detected in extracts of normal rat colon by employing the much more sensitive procedure of tanned cell hemagglutination inhibition, however, the concentration of the antigen in tumor was about 250-fold higher than in normal colon. Similar to human CEA, the rat tumor antigen was found to be heat stable, contained glycoprotein, migrated as a beta-globulin, and appeared at a high concentration in fetal intestines, however, the rat tumor antigen was serologically distinct from human CEA.
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PMID:A thermostable antigen characteristic for carcinogen-induced rat intestinal tumors. 81 15

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

Concanavalin A (Con A)-binding glycoproteins have been purified from Ehrlich ascites tumor cells by precipitation of cell extracts with Con A in agarose gels and by lithium diiodosalicylate (LIS) extraction. Antisera prepared against these two glycoprotein fractions indicate the presence of a minimum of five different antigens in the Con A-cell extract precipitate and a minimum of three different antigens in the LIS-extracted preparation. That both kinds of antisera are directed towards surface membrane antigens is strongly suggested by the fact that they give precipitin bands with purified plasma membrane from Ehrlich cells, they agglutinate whole cells, and they no longer give precipitin bands after absorption by whole cells. Cell extract material which was specifically eluted from a Con A-Sepharose 4B column with alpha-methylmannoside was recognized by antisera to both glycoprotein preparation, demonstrating that the antigens were Con A-binding components; material which did not bind the column failed to react with either antisera. Immunochemical analysis indicated that one of the antigens present in the LIS-extracted material was distinct from the five antigens prepared by lectin precipitation in agarose gels suggesting that a minimum of six individual Con A receptors are present on the surface of Ehrlich tumor cells. Immunochromatography was found to be a convenient method to purify the antigens obtained by the LIS extraction of Ehrlich cells.
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PMID:Heterogeneity of concanavalin A receptors on Ehrlich tumor cells. 82 60

In order to study the mechanism of tumor cell surface antigen shedding, galactosyltransferase levels were compared in 5 spontaneously metastasizing and 3 nonmetastasizing rat mammary tumors. The enzyme activity both with or without exogenous acceptors was higher in the metastasizing group. This difference did not seem to be due to the variation in levels of degrading enzymes such as pyrophosphatase or beta-galactosidase found in these tumors. Little difference in the biochemical properties of the enzyme was found between the two groups. Most of the enzyme activity (60-70%) was recivered in the microsomal frctosyltransferase was assayed in "purified" plasma membrane fractions, 70% of the activity was associated with the plasma membrane vesicles, in which the enzyme was enriched by factors of 10-40. The number of galactose acceptor sites on the plasma membranes increased in parallel to the metastasizing capacity, indicating the presence of larger numbers of incomplete glycopeptides on their cell surfaces. These findings seemed to indicate that the greater turnover of glycoprotein in the spontaneously metastasizing tumor cell surface was caused by the shedding of surface antigens into the systemic circulation of the host.
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PMID:Galactosyltransferase activity in metastasizing and nonmetastasizing rat mammary carcinomas and its possible relationship with tumor cell surface antigen shedding. 83 75


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