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:3.2.1.36 (hyaluronidase)
4,606 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The synthesis and secretion of mucin-like high-molecular glycoprotein was studied in 2 human colon cancer cell lines that spontaneously differentiate in culture (Caco-2 and T84) and in 2 cell lines that do not spontaneously differentiate (LS174T and HT29). Mucin, quantitated by 3H-glucosamine labelling and chromatography on Sepharose CL-4B was found to be produced by all 4 cell lines. The mucinous nature of the labelled high-molecular glycoprotein was verified by enzymatic degradation treatments (heparinase, hyaluronidase, chondroitinase ABC, and N-glycanase), alkaline-borohydride treatment, inhibition of labelling by the glycosylation inhibitor benzyl-alpha-GalNAc, and by CsCl-density-gradient centrifugation. In all 4 cell lines, an inverse correlation of mucin synthesis with cell density was demonstrated. In Caco-2 cells, the spontaneous post-confluent enterocytic differentiation with increased brush-border enzyme expression was associated with a decrease in mucin synthesis and in the activities of polypeptidyl GalNAc transferase and beta 1,3-galactosyltransferase activity. Using cDNA probes for 2 distinct human intestinal mucins (MUC2 and MUC3), we found that all 4 colon cancer cell lines expressed mucin message, but the types of mucin mRNA expressed differed. These data indicate that mucin-like glycoproteins can be synthesized by cell lines derived from non-mucinous colon cancer, whether or not they undergo spontaneous differentiation in culture. These cell lines may serve as in vitro models for studying apomucin heterogeneity and control of mucin gene expression.
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PMID:Mucin synthesis and secretion in relation to spontaneous differentiation of colon cancer cells in vitro. 172 5

An air-liquid interface (biphasic) primary culture system in which guinea pig tracheal epithelial cells maintain morphologic characteristics of differentiated epithelium has been developed in this laboratory. In this report, we compared quantitatively cell populations of 8-day cultures to those of epithelial mucosa in intact trachea. In addition, high molecular weight glycoconjugates released by the cultured cells were isolated and characterized. Quantitative morphometric analysis revealed similar volume densities of ciliated, secretory, basal, and "other" cells in cultures and in intact tracheal surface epithelium, although the cultures tended to have smaller cells and contained fewer basal cells. High molecular weight glycoconjugates released apically by cell cultures and excluded from Sepharose CL-4B columns contained approximately 5% hyaluronic acid but undetectable amounts of other proteoglycans, such as chondroitin sulfate, heparan sulfate, and dermatan sulfate. The hyaluronidase-resistant glycoconjugates exhibited a peak buoyant density at 1.49 g/ml on cesium chloride density gradient centrifugation and were shown to contain mucin-type carbohydrate to peptide linkages (i.e., GalNAc to ser/thr) and an amino acid composition typical of respiratory mucins. The results indicate that this organotypic cell culture system mimics quite closely morphology of mucosal epithelium in intact airways and that the cells release high molecular weight glycoconjugates with biochemical properties of mucin-type glycoproteins. Thus, this in vitro system appears well-suited for studies of mucin secretion and other functions of respiratory epithelial cells.
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PMID:Characterization of guinea pig tracheal epithelial cells maintained in biphasic organotypic culture: cellular composition and biochemical analysis of released glycoconjugates. 230 71

Two cases of an aggressive cutaneous carcinoma showed both squamous and adenomatous differentiation. These neoplasms invaded subcutaneous structures with a sclerosing pattern, making surgical resection difficult. Unlike the usual squamous carcinoma, glands and epithelial mucin (sialomucin) were produced. This mucin stained with mucicarmine and was sensitive to sialidase and resistant to hyaluronidase digestion. No mucin with similar histochemical properties was found in a study of 50 consecutive cutaneous squamous carcinomas and 50 consecutive basal cell epitheliomas from our files. Literature reports of histologically similar cutaneous carcinomas together with our experience with these two cases suggest aggressive behavior for this category of neoplasm.
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PMID:Adenosquamous carcinoma of the skin. An aggressive mucin- and gland-forming squamous carcinoma. 240 85

This study was undertaken to evaluate the relative utility of histochemical and immunohistochemical stains in diagnosing malignant mesothelioma of the thorax. We performed a battery of histochemical stains, including periodic acid Schiff (PAS) with and without diastase, mucicarmine, colloidal iron (Coll Fe) with and without hyaluronidase, and immunohistochemical stains for keratin and carcinoembryonic antigen (CEA) on 12 pleural mesothelioma specimens obtained from 11 patients, five primary pulmonary adenocarcinomas, and one metastatic adenocarcinoma each to pleura and pericardium. All diagnoses were established by autopsy or thorough clinical and surgical evaluation. The diagnosis of mesothelioma was established following rigid anatomic criteria. All tissue was formalin fixed and paraffin embedded. Commercially available reagents and antisera were used in all cases. Results showed a high rate of positivity for keratin and hyaluronidase-sensitive Coll Fe in the mesotheliomas while adenocarcinomas were uniformly positive for CEA and keratin and generally positive for PAS-D (diastase) and mucicarmine. Mesotheliomas were negative for CEA, mucin, and PAS-D. Positive keratin staining was also seen in the spindle cell components of mesotheliomas. Immunohistochemical stains often added significantly to our ability to establish the diagnosis of mesothelioma with confidence, since they were more frequently and more clearly positive than histochemical stains.
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PMID:Diagnostic histochemical and immunohistochemical studies in malignant mesothelioma. 243 7

The immunoreactivity of five antibodies was evaluated on six routinely processed mesotheliomas to evaluate their ability to distinguish mesothelioma from metastatic adenocarcinoma. The diagnosis in all cases was confirmed by electron microscopic examination and histochemical stains for neutral mucin (periodic acid-Schiff-diastase) and acid mucin (alcian blue with and without hyaluronidase). AE1, a monoclonal antikeratin antibody that stains most carcinomas, reacted with all six cases of mesothelioma. HMFG-2 and anti-epithelial membrane antigen (antibodies reactive with human milk fat globule proteins), two other closely related antibodies reactive with most carcinomas, also reacted with all of the mesotheliomas in the authors' series. A polyclonal antibody to carcinoembryonic antigen (anti-CEA) did not stain any of the mesotheliomas in their series. Anti-Leu-M1 did not react with the mesotheliomas. The authors conclude that none of these antibodies, when used alone on routinely fixed paraffin-embedded material, is both sensitive and specific in the distinction of mesothelioma from adenocarcinoma. However, immunoperoxidase studies using anti-CEA and anti-Leu-M1 may occasionally be helpful when used in conjunction with other histochemical stains and electron microscopic examination in distinguishing mesothelioma from metastatic adenocarcinoma.
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PMID:Immunohistochemical staining in malignant mesotheliomas. 244 94

Two children with advanced Wilms' tumor and one with extensive nephroblastomatosis showed artifactually elevated white blood cell (WBC) counts due to circulating mucin. Wilms' tumor is known to produce mucin identifiable in serum, urine, and touch imprints. To our knowledge, circulating mucin has not been described in nephroblastomatosis. When patients' blood was mixed with lysing reagent in the Ortho ELT-800, mucin was precipitated by acetic acid; this was confirmed by microscopy. Precipitates were counted as nuclei, producing abnormal WBC counts and histograms. When measured by the Ortho ELT-8/ws using osmotic lysis, the WBC counts matched hemocytometer counts. Mucin was not seen on Wright-stained smears but was evident with alcian blue staining and was largely abolished by hyaluronidase. Treatment led to disappearance of the artifactual WBC elevation.
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PMID:Circulating mucin in Wilms' tumor and nephroblastomatosis. Effect on leukocyte counts. 245 92

The antigenic determinant recognized by monoclonal antibody SPan-1 is greatly elevated in sera of patients with pancreatic cancer but not in sera of normal individuals. Here we describe the mucin-like characteristics of the SPan-1 antigen isolated from culture medium and xenografts of the human pancreatic cancer cell line SW-1990. YPan-1, another pancreatic cancer associated monoclonal antibody, also reacts with the SPan-1 antigen. The SPan-1/YPan-1 antigens have densities of 1.4-1.5 g/ml and elute in the void volume of Sepharose CL-2B columns. They are resistant to degradation by chondroitinase ABC, nitrous acid, and hyaluronidase but susceptible to protease digestion and reductive beta-elimination. All these characteristics suggest that the SPan-1 and YPan-1 determinants are carried on mucinous antigens. Both SPan-1 and YPan-1 immunoreactivities are unaffected by boiling or by alkylation and reduction of the mucins while they are abolished by mild periodate oxidation or neuraminidase and are markedly decreased by wheat germ agglutinin. Thus, their antigenic determinants are composed principally of carbohydrates with sialic acid, an absolute requirement for reactivity. However, the epitope specificities of SPan-1 and YPan-1 are different since YPan-1 does not compete with SPan-1 for binding to antigen. Moreover, YPan-1 and SPan-1 can be distinguished from several other sialic acid requiring, cancer associated antibodies such as B72.3, CSLEX-1, DU-PAN-2, OC-125, and 19-9 by either their epitope characteristics or their tissue reactivity patterns.
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PMID:Mucin-like antigens in a human pancreatic cancer cell line identified by murine monoclonal antibodies SPan-1 and YPan-1. 245 32

We characterized the chemical composition of mucins secreted by ferret tracheal explants and the activities of key mucin glycosyltransferases in ferret tracheal epithelium during a period of rapid postnatal maturation of the mucin-secreting structures. Ferret tracheal explants secrete three major groups of high molecular weight glycoconjugates: (1) those susceptible to bovine testicular hyaluronidase; (2) those resistant to hyaluronidase and exhibiting high density (p greater than or equal to 1.60 g/mL); and (3) those resistant to hyaluronidase and exhibiting low density (1.45 less than or equal to p less than 1.60 g/mL). The hyaluronidase-resistant, low-density glycoconjugates have typical mucin properties and constitute 36% of total glycoconjugates released in newborns but only 8% in adult ferrets. Mucin secretory rate per unit surface area of trachea progressively decreases with age. Mucin amino acid and total carbohydrate contents do not vary; however, the sialic acid content increases, and fucose content as well as blood group A activity of the mucins decreases with age. Four glycosyltransferases involved in mucin biosynthesis [Gal beta 3GalNAc:(GlcNAc-GalNAc)beta 6 N-acetylglucosaminyl-, GalNAc:beta 3 galactosyl-, Gal:alpha 2 fucosyl-, and GalNAc alpha 2----6 neuraminyltransferase] are present in tracheal epithelium of ferrets at all ages. Activities of all but the neuraminyltransferase decrease with age. The relatively greater neuraminyltransferase activity is consistent with increased incorporation of sialic acid into secreted mucins over the same age span. Conversely, diminution of fucosyltransferase relative to galactosyltransferase activity may contribute to the lower fucose content and lower blood group A activity of mucins secreted by mature ferret tracheas.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Developmental changes of ferret tracheal mucin composition and biosynthesis. 261 Dec 42

Monoclonal antibodies, 17B1 and 17Q2, which are specific for large molecular weight mucous glycoproteins of airway epithelium, have been used to develop an ELISA method to quantitate the tracheal mucins of humans and rhesus monkeys. The assay is a double-sandwich system that does not depend on either the binding of mucous antigens to the microtiter plate or the use of a second antibody. The assay protocol includes (1) coating the microtiter well with purified IgG of 17B1 or 17Q2, (2) incubating the wells with mucous samples, (3) binding of alkaline phosphatase-conjugated IgG to the wells, and (4) developing the color with phosphate substrate. This ELISA method is very sensitive for human and rhesus monkey tracheal mucins. Quantitation is not affected by the presence of various proteoglycans (keratan sulfate, hyaluronate, heparin, heparan sulfate, and chondroitin sulfate). However, the quantitation is affected by the treatment of antigen with periodic acid and endo-beta-galactosidase. Other enzymes (e.g., neuraminidase, hyaluronidase, chondroitinase, heparitinase, heparinase, fucosidase, keratanase) have no effect on the antigenicity of substrate. The quantitation is linear, with a concentration from 0.2 to 4 ng protein/sample. The ELISA method developed in this study should be useful for quantitating the mucin content of various biologic fluids, such as sputum, bronchoalveolar lavage, and media from cultures following various pharmacologic and physiologic manipulations.
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PMID:An ELISA method for the quantitation of tracheal mucins from human and nonhuman primates. 262 58

Colon cancer cells in culture synthesize and secrete mucin glycoproteins, which carry a number of cancer-associated antigens. However, the structures and mechanisms of biosynthetic processing are not well understood. Mucins synthesized and secreted by LS174T human colon cancer cells were compared to those in LS174T xenografts in athymic mice. Mucins radiolabeled with glucosamine or sulfate were purified by gel filtration and cesium chloride density gradient centrifugation. The mucins were of high molecular weight and were resistant to chondroitinase ABC, hyaluronidase and HNO2 treatment. They were, however, susceptible to pronase digestion and mild alkaline treatment. Using radiochemical precursors, the cellular mucin was shown to contain fucose, galactose, N-acetylgalactosamine, N-acetylglucosamine, N-acetylneuraminic acid, and sulfate. Oligosaccharides released by beta-elimination had N-acetylgalactosaminitol as the reduced amino sugar and also unreduced galactosamine, indicating that there is N-acetyl-galactosamine O-glycosidically attached to protein core and also peripheral N-acetyl-galactosamine not directly linked to protein. DEAE-cellulose chromatography of mucins showed two major peaks with both intracellular and secreted mucins, but xenograft mucins also had more acidic components. Sulfate-labeled mucins were shifted to less acidic peaks by neuraminidase digestion, which indicates that the same mucin molecules are both sialylated and sulfated. We conclude that the intracellular mucins of cultured colon cancer cells, those secreted into the medium, and those in nude mouse xenografts are chemically similar, but differ in sialic acid and sulfate content. This experimental model system, LS174T cells maintained in culture and as nude mouse xenografts, may be useful for further biosynthetic and structural studies of colon cancer mucin.
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PMID:Comparison of metabolically labeled mucins of LS174T human colon cancer cells in tissue culture and xenograft. 273 49


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