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)

Antisera reactive with the Abelson murine leukemia virus (A-MuLV)-specified P120 (anti-AbT sera) were produced in C57L/J mice. Of many strains tested, only C57L/J reproducibly rejected syngenic A-MuLV-induced tumor cells; after multiple immunizations their sera would immunoprecipitate both P120 and Moloney-MuLV (M-MuLV) proteins. Using labeled A-MuLV-induced nonproducer cells, only P120 could be detected by anti-AbT sera, suggesting that it may be the only A-MuLV-specified protein. Reactivity of anti-AbT sera with P120 was not blocked by M-MuLV virion proteins, implying that the sera recognize a portion of P120 that is not homologous to any M-MuLV product. Anti-AbT sera stained the surface of live, A-MuLV-transformed nonproducer cells in a two-stage immunofluorescence assay, and such staining was not blocked by M-MuLV protein. Also, intact A-MuLV-transformed cells absorbed much of the reactivity of certain anti-AbT sera for P120. Thus a portion of P120 appears to be exposed on the surface of transformed cells. P120 lacks detectable carbohydrate, is not affected by endoglycosidase H, and cannot be labeled by lactoperoxidase-catalyzed iodination. Thus P120 is an unusual surface protein.
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PMID:Preparation of syngeneic tumor regressor serum reactive with the unique determinants of the Abelson murine leukemia virus-encoded P120 protein at the cell surface. 9 72

By light microscopy the subdermal nodule of a patient with fibrodysplasia ossificans progressiva (FOP) had a fibromatoid histologic appearance. The cytoplasm of the cells stained strongly for mannose-rich glycoprotein with the concanavalin A-horseradish peroxidase (con A-HRP) method. The tumors also exhibited abundant hyaluronidase-digestible mucopolysaccharide in the interstitium with various basic staining reagents. This material appeared to consist principally of hyaluronic acid or chondroitin sulfate with few or mainly masked sulfate esters. At the ultrastructural level, cells interpreted as the tumor cells in the subdermal nodule from the patient displayed extremely hyperplastic granular reticulum and well-developed Golgi elements and appeared very active in synthesis and secretion of protein. The material in the dilated cisternae of the granular reticulum stained for glycoprotein with the con-A-HRP method. Macrophages which comprised the other main cell type in the nodules commonly contacted the tumor cells and occasionally evidenced engulfment of these cells. The intercellular matrix of the nonossified subdermal nodule exhibited greatly increased mucosubstance and, by electron microscopy, showed an unusual network of dialyzed iron-reactive acid muco-substance in the interstitium.
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PMID:Histochemical and ultrastructural studies in fibrodysplasia ossificans progressiva (myositis ossificans progressiva). 14 Dec 14

Rat chloroma cells have been propagated in permanent suspension cultures and are grown in Dulbecco's modified Eagle's medium with 10% fetal calf serum and 2.5% horse serum. Several lines have been established; the one of longest duration, Mia C51, has been maintained for over 18 months and has undergone over 100 transfers. Mia C51 cells have a doubling time of 12 hr and maintain many of the properties of the parent tumor, including the characteristic greenish color with high myeloperoxidase activity, an an aneuploid chromosomal pattern, and intact tumorigenicity. They will uniformly produce greenish chloroma tumors when injected into newborn rats. Electron microscopic examination of chloroma tumors and the cultured cells derived from them reveal the presence of extracellular mature and immature type C virus particles morphologically typical of oncornaviruses. Chloroma cells obtained from tumors that lost their alkaline phosphatase activity after repeated transfer regain full activity in culture. Studies using the antigen-antibody crossed electrophoresis indicate that the loss of alkaline phosphatase activity represents a true decrease in alkaline phosphatase protein, which is restored under culture conditions. The availability of a permanent chloroma cell line in culture that maintains the biological properties of the parent tumor provides a useful model for the study of myeloid leukemia.
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PMID:Characteristics of rat carcinoma in culture. 16 71

A cytotoxic effect of human neutrophils on mammalian tumor cells is demonstrated. Cytotoxicity depends on the presence of intact neutrophils, phagocytosable particles, and a halide cofactor and is inhibited by azide, cyanide, and catalase. Neutrophils from patients with myeloperoxidase (MPO) deficiency or defective H1O2 production are not cytotoxic, but activity is resotred by addition of purified MPO or H2O2 respectively. The findings support a mechanism involving the phagocytosis-induced extracellular release of MPO and H2O2 and their reation with a halide cofactor to damage the target cells.
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PMID:Neutrophil-mediated tumor cell cytotoxicity: role of the peroxidase system. 16 58

Nonimmunological defenses are very diverse in type. Some are directed against already transformed cells and belong to mechanisms of containment. Others exert a surveillance by preventing or inhibiting initial events of carcinogenesis. Chalones and oncolytic factors in sera and exudates are agents of containment. Under appropriate circumstances, the autoxidation of thiols and the formation of mixed disulfides lead to destruction of tumor cells in vitro and in vivo. Both processes involve the generation of superoxide radicals and of hydrogen peroxide which, in turn, activate the peroxide:peroxidase:halide system. Thiol:disulfide ratios and interchange codetermine the antioxidative activity of cellular membranes, thus bearing on carcinogenesis. Many aliphatic and aromatic antioxidants are endowed with anticarcinogenic properties. The fact that they are inhibitors of free radical processes corroborates the increasingly evident role of free radicals in carcinogenesis. Endogenous antioxidants and exogenous ones in foods are agents of surveillance. Antioxidant activity, linked with the ergastoplasm, points to a homeostatic mechanism that prevents self-accelerating chain reactions from leading to membrane damage or to carcinogenesis. Carcinogens can also be inactiviated by microsomal enzymes belonging to an overall mechanism of detoxification. Activity levels of these systems depend on diet and state of nutrition. They may be naturally very low, but they can be increased with various inducers.
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PMID:Nonimmunological host defenses: a review. 17 22

Cell membranes from mouse L-cells (L-B82), rat hepatoma (HTC-H1), and three clones of their somatic cell hybrids (07, V4a, and V5) showing different degrees of density-dependent inhibition of growth were analyzed by polyacrylamide gel electrophoresis. The membrane polypeptides of the hybrid clones were all similar and all showed higher proportions of polypeptides with molecular weights of 56,000 and 45,000 than their parents of their normal counterparts. The major glycoprotein form cell hybrids appeared to be identical with that of rat liver or rat hepatoma cells and different from that of L-cells. One hybrid showed density-dependent inhibition growth; the other two, like both parents, did not. All produced tumors in nude mice, although tumor production by the hybrids was delayed. A large external protein (M.W. 240,000) iodinated by lactoperoxidase-catalyzed reaction was virtually missing in the parents but was present at high levels in all their hybrid clones. Thus, there was a lack of correlation between the presence of this protein, growth control in vitro, and tumorigenicity. Furthermore, no correlation was seen between agglutination of these cells by concanavalin A and tumorigenicity. The factors controlling these membrane properties thus are independent of density-dependent inhibition of growth and of those controlling the expression of cancer.
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PMID:Characteristics of cell membranes from somatic cell hybrids between rat hepatoma and mouse L-cells. 17 11

Immunoperoxidase staining for Regan isoenzyme of alkaline phosphatase was performed on cryostat sections of five human tumor tisssues. With a direct immunoperoxidase staining for the localization of Regan isoenzyme at the light and electron microscope levels, sections previously fixed with 0.05 M phosphate-buffered 4% paraformaldehyde were reacted with rabbit antisera to human placenta alkaline phosphatase conjugated to horseradish peroxidase. Comparison of conventional histochemistry and immunohistochemistry for Regan isoenzyme indicated that strong specific immunoperoxidase staining appeared on the cell membrane surface, and a diffuse one, in the cytoplasm of lung and colon cancer tissue cells showing L-phenylalanine-sensitive alkaline phosphatase. No immunoperoxidase reaction was obtained in tumor cells showing sensitivity to L-homoarginine or lacking aklaline phosphatase activity.
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PMID:Direct immunoperoxidase staining for Regan isoenzyme of alkaline phosphatase in human tumor tissues. 18 52

Cationic proteins purified from human polymorphonuclear leukocyte granules exert a cytotoxic effect on mammalian tumor cells. This effect is time and concentration dependent, is inhibited by the anionic agent heparin, and is enhanced by preheating the cationic proteins. Other strongly basic proteins (histone, protamine) also exhibited cytotoxic activity. Myeloperoxidase isolated from human leukocytes is cytotoxic when combined with H2O2 and chloride. Under these conditions, the potency of the myeloperoxidase-mediated system is greater than that of the cationic proteins.
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PMID:Cytotoxicity for tumor cells of cationic proteins from human neutrophil granules. 18 2

Cytologic and cytochemical examination of eighteen cases of round-cell sarcoma of bone allowed classification of these tumors into four cytologic groups. Additional cytochemical examinations based on the PAS and D-PAS reactions, and the demonstration of the activity of peroxidase, naphtol-ASD-Chloracetate esterase, alpha-naphthylacetate esterase, naphthol-AS-acetate esterase with and without sodium fluoride inhibition, acid and alkaline phosphatases yielded no evidence of uniform behavior among the individual groups or within any single group. The studies showed that a positive glycogen reaction cannot be used as a basic criterion for the classification of such tumors as Ewing's sarcoma and for regarding them as a uniform tumor group. It is possible that a pool of tumors is involved, including tumors of monocytic and probably of lymphocytic origin, reticulum-cell sarcoma, tumors of myelocytic and erythroplastic origin, stem-cell tumors, and endothelial-cell tumors. Histologic examination alone is not sufficient for the classification of round-cell sarcomas of bone, and it should be supplemented by cytologic and cytochemical or histochemical methods. Osteosarcomas (23 cases) and chondrosarcomas (8 cases) display cells which are characteristic for these tumors and which could be correlated with their benign counterparts, osteoblasts and chondroid cells. The histologically recognizable degree of malignancy of chondrosarcoma can be evaluated better with the cytologic than with the histologic technic. Indications of the possibilities of differential diagnosis based on the cytologic pictures of benign and malignant osteoplastic and chondroplastic tumors, giant-cell tumors and chordoma are discussed.
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PMID:Cytologic and cytochemical behavior of primary malignant bone tumors. 18 69

Yoshida ascties sarcoma and its variants and several azo dye-induced ascites hepatomas of rats were examined by an immuno-peroxidase technique to demonstrate surface immunoglobulins. More than 60% of the tumor cells in 8 ascites tumors showed positive surface staining (Group A), whereas the other 9 tumors were less than 15% positive (Group B). One tumor showed 34% positive reaction. The staining did not show capping. Six of the 8 Group-A tumors were single cell type, while 5 of the 9 Group-B tumors were island type. Intravenous transplantation rate was very low (less than 10%) in 2 of the 6 Group-B tumors, but only 1 of the 7 Group-A tumors showed moderately low (40%) intravenous transplantation rate. All of the 8 Group-A tumors showed survival period of less than 35 days after intraperitoneal transplantation, while the survival period was more than 45 days in 3 out of the 9 Group-B tumors.
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PMID:Electron microscopic evidence of surface immunoglobulins in Yoshida ascites sarcomas and ascites hepatomas. 19 24


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