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:3.2.1.17 (lysozyme)
21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hepatocellular carcinoma with osteoclast-like giant cells (hepatic giant cell carcinoma [HGCC]) is a rare entity, with only three cases reported. The tumor is histologically similar to giant cell tumor (GCT) of bone, and the origin of the multinucleated giant cells and mononuclear stromal cells has not been determined. The purpose of this report is to present a case of this rare tumor and compare its ultrastructural and immunohistochemical features with those of a conventional GCT of bone. Histologically, the HGCC consists of sheets of osteoclast-like giant cells with a background of mononuclear cells. The giant cells lack the pleomorphism seen in hepatocellular carcinomas with anaplastic giant cells. At the light microscopic level, most of this tumor was nearly identical to a GCT of bone, but several microscopic fields (less than 5% of the tumor) had the histologic appearance of a "usual" hepatocellular carcinoma. The hepatic tumor was negative for HAM 56, epithelial cytokeratins, muramidase, and alpha-1-antitrypsin, with only focal positivity for chymotrypsin in mononuclear and giant cells. The GCT was strongly positive for alpha-1-antitrypsin and chymotrypsin in both the mononuclear and giant cells and showed focal, weak staining for AE1 and AE3 in the mononuclear stromal cells. Ultrastructurally, both mononuclear and giant cells of the HGCC showed features typical of hepatocellular carcinoma. Although the patient presented in this report died, the pattern of growth was different from most hepatocellular carcinomas. The overall histologic features of this tumor are distinctive and appear to justify separating this variant from other types of hepatocellular carcinoma.
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PMID:Hepatic giant cell carcinoma. An ultrastructural and immunohistochemical study. 215 1

We have immunohistochemically localized fibronectin, lysozyme and alpha-fetoprotein (AFP) in 21 human hepatocellular carcinoma (HCC) tissues obtained by surgical resection at both light and electron microscopic levels. Three distinct distribution patterns of fibronectin (sinusoidal, periacinar, and pericellular patterns) were observed. The sinusoidal and periacinar patterns were mainly observed in HCC of pseudoglandular or trabecular patterns and of Edmondson's grade I or II, whereas the pericellular pattern was observed in HCC of compact or trabecular patterns and of Edmondson's III grade, suggesting that the pericellular fibronectin was rather associated with undifferentiated HCC. Electron microscopic observation of the pericellular fibronectin showed fibronectin to be present in the dilated intercellular spaces where microvilli were moderately developed. We observed intracytoplasmic staining of fibronectin in 2 of the 21 HCC cases. By immunoelectron microscopy, fibronectin was observed in the endoplasmic reticulum (ER) of some HCC cells. In the 21 HCC cases, lysozyme-positive cancer cells were observed in 10 cases, and AFP in 6 cases. At the ultrastructural level, lysozyme was identified in the ER and the perinuclear spaces of HCC cells, suggesting that lysozyme was synthesized by these cells. Lysozyme-positive cases tended to be more frequently observed in cases with the pericellular pattern of fibronectin rather than those with sinusoidal or periacinar patterns.
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PMID:Immunohistochemical study of fibronectin, lysozyme, and alpha-fetoprotein (AFP) in human hepatocellular carcinoma. 243 68

Two hepatocellular carcinomas and six hepatoblastomas were examined for the presence of 13 antigens using immunoperoxidase, avidin-biotin, staining techniques. Primary antibodies were directed against alpha-fetoprotein (AFP), alpha-1-antitrypsin (AAT), lysozyme (LYS), carcinoembryonic antigen (CEA), human chorionic gonadotropin (HCG), glial fibrillary acidic protein (GFAP), neuron specific enolase (NSE), epithelial membrane antigen (EMA), hepatitis B surface antigen (HbSA), lactoferrin (LF), desmin (DES), vimentin (VIM), and keratin (KER). Except for HbSA, the antigen staining pattern was unable to differentiate between hepatoblastoma and hepatocellular carcinoma. Both neoplasms where positive for AFP, AAT, CEA, EMA, and KER; however, neither stained for GFAP, NSE, LYS, LF, HCG, or DES. Vimentin was weakly positive in those hepatoblastomas where mesenchymal tissue was present in the tumor. Only the tissue adjacent to hepatocellular carcinomas stained positively for HbSA and correlated with the elevated serum levels of HbSA.
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PMID:Patterns of antigen expression in hepatoblastoma and hepatocellular carcinoma in childhood. 248 9

We have isolated two overlapping recombinant lambda-phage clones from a genomic lambda-EMBL3 library containing 25 kb of the human lysozyme gene region. Furthermore a full-lenght human lysozyme cDNA clone of 1.5 kb was isolated from a human placenta cDNA library. Nucleotide sequences of the entire structural gene and the cDNA clone were determined. The human lysozyme gene spans 5856 bp and its sequence organization with four exons and three introns is homologous to the chicken lysozyme gene and the human alpha-lactalbumin gene. Human and chicken lysozyme genes differ mainly in the size of their introns and 3' non-coding region. Four Alu repetitive elements were found in the human lysozyme gene, one in each intron and one on the fourth exon. Lysozyme transcripts of 1.6 kb and 0.6 kb in size were detected in human myeloid cell lines U-937, HL-60 and THP-1 and surprisingly in human hepatoma cell lines HepG2 and Hep3B. The lysozyme gene locus was assigned to human chromosome 12 by hybridization to a panel of DNAs from human-rodent somatic cell hybrids.
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PMID:The human lysozyme gene. Sequence organization and chromosomal localization. 254 58

Conditioned medium (CM) obtained from a human hepatoma cell line, SK-HEP-1, contains colony-stimulating factors (CSFs) active on murine and human bone marrow-derived granulocyte and macrophage colony-forming units (CFU-GM) and a factor capable of inducing granulocyte-macrophage differentiation (GM-DF) of murine myelomonocytic leukemic cells WEHI-3B(D+) and human promyelocytic leukemic cells HL-60 when assayed in semisolid agar cultures. The human active granulocyte-macrophage colony-stimulating factor (GM-CSF) for day 7 CFU-GM and the GM-DF for WEHI-3B(D+) and for HL-60 are not separable by acrylamide agarose column chromatography, eluting at an apparent molecular weight between 20,000 and 35,000 daltons, or by isoelectric focusing (isoelectric point, pH 5.4). In addition, SK-HEP-1 CM contains erythroid burst-promoting activity (BPA) and a factor that promotes the growth of human mixed colonies. SK-HEP-1 cells, which grow as an adherent monolayer, appear not to be endothelial or monocytic in origin since by immunofluorescent staining they are negative for Ia (HLA-DR), monocyte antigen 1 and 2, lysozyme, and factor VIII-related antigen. Positive immunofluorescent staining for keratin and fibronectin suggests the possibility that SK-HEP-1 is an epithelial cell line. Constitutive production of GM-DF as well as other hematopoietic activities including GM-CSF, erythroid BPA, and an activity that promotes the growth of human mixed colony progenitors by a human epithelial tumor cell line, SK-HEP-1, suggests that this cell line is a valuable resource for both large-scale production of these factors and the cloning of the gene(s) that code for these regulators.
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PMID:Constitutive production of leukemia differentiation, colony-stimulating, erythroid burst-promoting, and pluripoietic factors by a human hepatoma cell line: characterization of the leukemia differentiation factor. 299 Jun 10

By fusion of C3H/HeJ splenic adherent mononuclear cells enriched for macrophages with HPRT-deficient C57L/J HH- hepatoma cells, we have generated six macrophage-hepatoma hybrid clones. The hybrid nature of isolated clones was demonstrated by karyotypic analysis. The hybrid clones were screened for macrophage properties by assaying the presence of two enzymes: nonspecific esterase and lysozyme. Three of six hybrids expressed higher amount of Ia antigen and less amount of FcR; the other three hybrids expressed higher amounts of Fcr, but no Ia antigen. Phagocytosis of serum-opsonized beads is positively correlated with FcR expression, while the proliferation of antigen-primed lymphocytes is only induced by antigen-pulsed hybrids expressing Ia antigen. One hybrid clone (MH3-1) secreted significantly higher level of PGE2 and also expressed Ia antigen with higher ability of antigen-presentation. The data suggest that the cell hybridization can segregate macrophage-featured phenotypes into different hybrid clones which perform distinct functions. It may facilitate the study on the relationship of macrophage functions and the relationship between the functions and defined cell structure.
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PMID:Generation of phenotypically distinct macrophage-hepatoma hybrid clones. 347 90

Hydrosoluble substances from BCG were prepared by cold water extraction and by hot phenol-water extraction. Chemical analyses revealed that both of them were derived from cytoplasm. The cold water extract (CWE) was effective in the treatment of C3H/He mice which had received an intraperitoneal inoculation of a syngeneic ascites hepatoma, MH134. The growth of a graft in footpad of mastocytoma P815 in CDF1 mice was retarded by intraperitoneal injections of CWE. A peptidoglycan from cell wall prepared by digestion with lysozyme exerted no antitumor activity in the same experimental condition as for the evaluation of antitumor effect of CWE. These results indicate that the antitumor activity of CWE was not due to the presence of a cell wall component.
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PMID:Chemical analyses and antitumor activity of hydrosoluble substances from Mycobacterium bovis, strain BCG. 619 9

Protamine sulfate reversibly inhibits serum-induced mitogenic stimulation of several nontransformed and neoplastic cell types in vitro. Fifty percent inhibition was induced by approximately 120-150 micrograms protamine sulfate/ml. Cells were affected directly, and inhibition depended on the duration of cell exposure. Heparin, chondroitin sulfate, heparan sulfate, and dextran sulfate neutralized protamine sulfate effects during the early stages of treatment. Nontransformed cells [bovine aortic endothelial cells, adult human gingival fibroblasts (strains 423 and 1101), fetal rat skin (strain 921-K) and muscle fibroblasts] required longer exposure to induce inhibition than did neoplastic cells [rat 3-methylcholanthrene-induced fibrosarcoma cell lines (MCA-6 and MCA-9), a macrophage-like cell line (NCTC-3749), Walker 256 rat carcinoma cells (ATCC-CCL-38), rat Morris hepatoma cells (ATCC-CCL-144), murine melanoma cells (B16), and rat bladder squamous cell carcinoma cells (804-G)]. Other polycationic compounds, including histone type VIII-S, poly-L-lysine, poly-L-arginine, and protamine (free base), were also effective inhibitors, whereas the basic proteins cytochrome c and lysozyme had no effect. Poly-L-histidine, poly-L-glutamic acid, poly-L-aspartic acid, and dextran blue also had no inhibitory effect.
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PMID:Protamine sulfate inhibition of serum-induced mitogenic responses: differential effects on normal and neoplastic cells. 621 Mar 90

Cross-linked dimers of ribonuclease, added at a concentration of 0.05 mg/ml to the culture medium of hepatoma (HTC) cells, were previously shown to inhibit intracellular degradation of peroxidase taken up by endocytosis. Intracellular localization showed that endocytosed peroxidase does not reach lysosomes in dimer-treated cells. The present study shows that preloading of lysosomes with fluorescent anti-peroxidase IgG, obtained by exposing HTC cells for 48 h to 0.1 mg of antibody/ml, restores intracellular degradation of endocytosed peroxidase. Moreover, accumulation of peroxidase into lysosomes, which no longer occurs in dimer-treated cells, occurs again under these conditions. We conclude that inhibition of transfer of peroxidase from phagosomes to lysosomes is most likely to be the alteration resulting from the exposure of the cells to ribonuclease dimer, rather than inhibition of fusion between phagosomes and lysosomes. The dimer of another basic protein, lysozyme added at a concentration of 0.2 mg/ml to the culture medium, is shown to induce the same type of effects as does the dimer of ribonuclease; the half-life of endocytosed peroxidase increased from 5 to 15 h after 2 h exposure of HTC cells to dimerized lysozyme. The effect of both dimers on intracellular protein processing can be reversed by addition of 100 mm-galactose to the culture medium, up to 5 h after pretreatment of the cells. The dimers of ribonuclease A or of lysozyme have thus probably the same mechanism of action. Evidence that the two dimers share the same binding sites on the cells is presented.
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PMID:Effects of cross-linked dimers of ribonuclease A or of lysozyme on the processing of endocytosed peroxidase by hepatoma cells. 628 32

Radioiodinated proteins were introduced into hepatoma tissue culture (HTC) cells by erythrocyte ghost-mediated microinjection, and their degradation was studied. 125I-bovine serum albumin and 125I-lysozyme were degraded with half-lives of about 7 and 11 h, respectively. The process was ATP-dependent. The breakdown of these proteins was not inhibited by the following inhibitors of lysosomal proteolysis: NH4Cl, methylamine, chloroquine, leupeptin, or antipain. Methylation of 94% of the amino groups of bovine serum albumin or 99% of the amino groups of lysozyme had little effect on the rates of their degradation in HTC cells. In contrast, methylation almost completely inhibited the ATP-dependent proteolysis of both proteins in reticulocyte lysates. Methylated bovine serum albumin was not detectably demethylated in HTC cells. It is concluded that in HTC cells, bovine serum albumin and lysozyme are degraded by a nonlysosomal pathway which differs from the ubiquitin-dependent proteolysis system of reticulocytes in that it does not require free amino groups.
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PMID:Degradation of microinjected methylated and unmethylated proteins in hepatoma tissue culture cells. 688 59


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