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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A clonal strain of rat glial tumor cells was shown to produce the acid mucopolysaccharides, hyaluronic acid, chondroitin 4-SO(4), and heparan sulfate in tissue culture. The mucopolysaccharides were isolated both from the growth medium and the cells.
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PMID:Synthesis of acid mucopolysaccharides by glial tumor cells in tissue culture. 424 92

Two mucopolysaccharides, chondroitin 4-sulfate (97.8%) and hyaluronic acid (1.2%), were isolated after exhaustive proteolysis of a transplantable chondrosarcoma of the rat. The chondroitin 4-sulfate was fractionated into three fractions of varying degrees of sulfation and chain length. Keratan sulfate and chondroitin 6-sulfate were absent. Extraction of the fresh tumor gave two protein-polysaccharides of similar carbohydrate composition, one soluble in 0.5 M NaCl, the other insoluble. The latter was solubilized in 4 M guanidine.HCl. A dialyzable fraction from the 4 M guanidine solution may be responsible for the insolubility. Both protein-polysaccharides were antigenic and cross-reacted with similar fractions of bovine and human cartilage.
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PMID:Mucopolysaccharide and protein--polysaccharide of a transplantable rat chondrosarcoma. 425 39

The metabolism of acid mucopolysaccharides in Novikoff hepatoma and in hepatoma BW7756 was studied using the precursors -35S-sulfate, -H-glucosamine and -14C-galactosamine. There is an active formation of sulfated mucopolysaccharides at the mitochondria and cell membrane level. Hepatoma cells synthesize heparin to a lower rate than liver cells. In ascitic as well as in solid tumors there is a considerable accumulation of hyaluronic acid which does not seem to be elicited by the tumor cells but by the surrounding tissues. The possible implication of the low heparin production in the cell membrane characteristics is discussed.
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PMID:Metabolism of acid mucopolysaccharides in hepatoma and in normal liver. 437 92

Malignant mesotheliomas were induced in the rat peritoneum by a single injection of chrysotile or crocidolite asbestos fibers. The immediate toxicity of the fibers was noted in both groups of animals, producing approximately 40% mortality, within 8 days after the injection associated with acute peritonities. Tissue reactions to these two types of asbestos were significantly different. Crocidolite fibers were easily seen by light microscopy, in the tissue sections throughout the period of study, and they produced foreign-body giant cell granulomas. However, giant cells were not seen in chrysotile granulomas, and the asbestos fibers were only seen by electron microscopic study. They appeared to be coated by a protein-like substance. During earlier stages of tumorigenesis, the epithelioid and/or mixed cell type mesotheliomas seemed to have no specific relationship to granulomas, but pure spindle cell tumors were seen to develop in close relationship to granulomas, and they appear to be fibrosarcomas. Electron microscopic and histochemical methods were used to define the morphologic characteristics of the tumor cells. The formation of hyaluronic acid was found in cells of the epithelioid type, contrasted with extracellular accumulation in the spindle cell tumors.
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PMID:Acute and chronic effects of intraperitoneal injection of two types of asbestos in rats with a study of the histopathogenesis and ultrastructure of resulting mesotheliomas. 468 12

In this review, evidence that proteoglycans are involved in cell adhesion and related behavior is considered, together with their putative role(s) during tumorigenesis. Proteoglycans are large, carboxylated and/or sulfated structures that interact with specific binding sites on cell surfaces. Their distribution and synthesis in tissues alter with the onset of tumorigenesis so that hyaluronic acid is generally increased and heparan sulfate decreased in the developing tumor and surrounding tissue. However, the precise role of proteoglycans during the tumorigenic process is far from clarified. Data suggest any putative roles will be related to the adhesive properties that these molecules confer to cells. Hyaluronic acid and chondroitin sulfate appear to be weakly adhesive molecules that may promote 'transformed' characteristics when they occur on cells in large amounts. These characteristics include reduced cell spreading, increased cell motility, as well as reduced contact inhibition. Consistent with such properties, neither hyaluronic acid nor chondroitin sulfate are localized in specialized adhesion sites such as focal or close contacts. In contrast, heparan sulfate is associated with increased cell-substratum adhesion and is involved in the spreading of cells onto fibronectin and other substrata. Its presence is generally associated with reduced motility and with a well-spread morphology. Unlike hyaluronate and chondroitin sulfate, heparan sulfate is found in specialized contacts. These adhesive properties of proteoglycans predict an instructive role in tumor development, and recent experiments have defined an involvement of these molecules in metastatic arrest. Additional studies utilizing invasive and metastatic tumor variants including tumor cells that employ different mechanisms to invade are required to clarify the role of proteoglycans in tumor progression.
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PMID:Proteoglycans and cell adhesion. Their putative role during tumorigenesis. 608 29

Four cases of mesothelioma were studied histologically and electron microscopically. One of them showed a pure epithelial type of the peritoneal origin, characterised by a tremendous production of hyaluronic acid. The other three tumors originated from the pleura revealed a histology of biphasic type mesothelioma, which showed an admixed tubular and fibrous pattern and consisted of small-sized cells with slight atypia. However, in some places of these tumors they showed considerable atypical features appearing like an anaplastic or squamoid carcinoma and/or spindle cell sarcoma. Hyaluronic acid was histologically demonstrated in the cytoplasmic vacuoles as well as in the luminal space surrounded by the tumor cells. Electron microscopically, varied numbers of microvilli and desmosome-like attachments were found on the surface of the tumor cells. Mitochondria were small and round. Well-developed rERs tended to encircle mitochondria and to dilate forming cisternae. Various amounts of microfilaments were found in the cytoplasm. The tumor cells which were rich in the latter two components, dilated rERs and microfilaments, resembled fibroblasts. Some tumor cells had phagosomes including dense and fine granules similar to ferritin, suggesting their phagocytotic activity. The hyaline matrix, common to the biphasic type tumor which was largely composed of dense collagenous tissues, was demonstrated to contain hyaluronic acid by histochemistry, and it was suggested that some secretory substances of the tumor cell may participate in composing the hyaline matrix to some extent.
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PMID:Mesothelioma. Histological and electron microscopic study of human cases. 608 95

The authors report the autopsy case of a 73-year-old man with widespread, metastatic, malignant chondroid syringoma, with a long clinical history. Three years after resection of the primary tumor on the back, the tumor recurred at the same site, metastasized to the cervical lymph nodes 7 years later, and finally, after 13 years exhibited widespread metastases. Histologically, the tumor showed cords and nests of cuboidal or polygonal tumor cells with little cellular pleomorphism and few mitoses surrounded by a mucoid matrix. Histochemically, the matrix contained hyaluronic acid and sulfated acid mucopolysaccharides, such as chondroitin sulfate A and/or C. To the knowledge of the authors there have been nine reported cases of malignant chondroid syringoma in the English literature, four of which had distant metastasis. A review of the literature reveals that malignant chondroid syringoma is more common in women and occurs most often in trunk and extremities, which is in contrast to its benign counterpart, its histologic appearances vary greatly, and it may even have benign appearances.
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PMID:Malignant chondroid syringoma. Report of a case with widespread metastasis and review of pertinent literature. 619 72

Six cases of synovial sarcoma were examined histochemically in order to clarify the components of mucosubstances in the tumor tissues. The tumors were classified into 1) monophasic type, 2) predominantly monophasic type with focal biphasic differentiation, and 3) biphasic type. The former two groups and sarcomatous areas in the biphasic tumors contained various amounts of hyaluronic acid, chondroitin sulfate, and, in some cases, heparitin sulfate. By contrast, the epithelioid regions in the biphasic-type tumors had periodic acid-Schiff-positive glycoproteins which contained various amounts of sialic acid, in addition to hyaluronic acid and chondroitin sulfate. The significance of the presence of glycoproteins in the mesenchymal tumors is emphasized. It seems likely that the synovial sarcomas contain various kinds of mucosubstances and that sensitivity to hyaluronidase treatment is not necessarily the diagnostic criterion of synovial sarcoma.
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PMID:Histochemical characterization of mucosubstances in synovial sarcoma. 620 16

We have examined the ability of cultured human glioma cells to elicit allogeneic cytolytic lymphocyte responses in vitro in order to delineate properties of glioma cells that may contribute to their ability to escape cellular immune attack. When glioma cells were cultured together with allogeneic peripheral blood mononuclear cells (PBMC) in mixed lymphocyte-tumor cultures (MLTC), it was observed that cells from eight of 12 glioma lines were surrounded by clear pericellular "halos," which appeared to impede contact between PBMC and the glioma cells. Enzymatic, histochemical, and immunochemical studies indicated that these halos represented glycosaminoglycan (GAG) coats that contained hyaluronic acid (HA) as a major constituent. Electron microscopic studies demonstrated the presence of many thin microvillous processes spanning the width of the halos. The presence of GAG coats around glioma cells in MLTC reduced the generation of cytolytic T lymphocytes specific for antigens on the glioma cells. Likewise, these cell coats decreased the lysis of glioma cells by cytolytic lymphocytes, once generated. The production of thick coats of GAG by glioma cells was induced by interaction of glioma cells with a nondialyzable factor produced by PBMC in culture. This factor did not cause glioma cells to release increased amounts of HA into the medium, but rather increased the production of HA that remained associated with the glioma cell surface. The formation of thick, protective GAG coats by glioma cells as a result of their interaction with the PBMC-derived factor constitutes a nonspecific suppressor mechanism that may contribute to the ability of this class of human solid tumors to evade cellular immune attack.
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PMID:In vitro studies on the cell-mediated immune response to human brain tumors. II. Leukocyte-induced coats of glycosaminoglycan increase the resistance of glioma cells to cellular immune attack. 623 97

A synovial sarcoma of the abdominal wall in a 56-year old woman showed the typical features of this tumor type. Histologically a characteristic biphasic cellular pattern with epithelium-like cell complexes and sarcomatous spindle cell areas was found. The histochemical examination revealed that tumor cells synthesize glycoproteins and weakly acid glycosaminoglycans (mainly hyaluronic acid). Electron microscopically the tumor cells in epithelium-like cell islets were sometimes arranged in gland-like formations with microvilli at the luminal side, specialized intercellular junctions and a peripheral basement membrane-like condensation of the ground substance. There was no fundamental cytological difference between cells of epithelium-like and spindle cell areas. Generally the tumor cells imitated cells of the synovial membrane and we found no evidence for origin from cells of the nerve sheath. Because of the submicroscopic relationship and histochemical similarities of synovial sarcomas and mesotheliomas we suggest that they should be united in a group of sarcomas with possible biphasic cellular pattern, while preserving their clinicopathologic definition.
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PMID:Synovial sarcoma of the abdominal wall. Light microscopic, histochemical and electron microscopic investigations. 625 40


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