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)

12-O-Tetradecanoylphorbol-13-acetate, a potent promoter of carcinogenesis in mouse skin, enhanced differentiation of cultured mouse myeloid leukemia cells (M1) induced by human urinary protein or by lipopolysaccharide from Salmonella typhosa. 12-O-Tetradecanoylphorbol-13-acetate enhanced differentiation of all the markers tested, such as phagocytosis, Fc rosette formation, lysozyme activity, and morphological change. Other potent tumor-promoting macrocyclic plant diterpenes also enhanced the induction of differentiation, but no-tumor-promoting diterpenes did not. These findings were in marked contrast with generally accepted findings on the inhibitory effect of 12-O-tetradecanoylphorbol-13-acetate on terminal differentiation observed in other cell culture systems but consistent with the observations with some kinds of leukemia cells.
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PMID:Enhancing effect of phorbol esters on induction of differentiation of mouse myeloid leukemia cells by human urinary protein and lipopolysaccharide. 29 79

The ionic complex between lysozyme and either Escherichia coli DNA or pBR322 DNA was not crosslinked by two systems capable of producing nanomolar amounts of hydroxyl radicals, the oxidation of xanthine by xanthine oxidase and the iron catalyzed oxidation of ascorbic acid. Nor did effective crosslinking occur with micromolar quantities of hydroxyl radicals raised by the addition of adenosine nucleotides to ferrous iron and hydrogen peroxide. In this case, radical content was estimated by colorimetric analysis of formaldehyde following hydroxyl radical oxidation of dimethyl sulfoxide. Similar amounts of radicals generated by pulse radiolysis in a nitrous oxide atmosphere failed also to induce crosslinking. These findings do not support a role for hydroxy radicals in the N-acetoxy-2-acetylaminofluorene induced crosslinking of DNA to lysozyme proposed earlier.
Carcinogenesis 1985 Dec
PMID:Hydroxyl radicals do not crosslink a DNA-lysozyme complex. 299 38

12-)-Tetradecanoylphorbol-13-acetate (TPA), the prototype polyfunctional diterpene ester tumor promoter of two-step carcinogenesis in mouse skin, induced differentiation of human promyelocytic leukemia cells (HL-60) in culture. Differentiation of HL-60 cells was characterized by increased phagocytosis, increased lysozyme activity (EC 3.2.1.17) in the growth medium, and changes in morphology to those characteristics of more mature cells resembling macrophages. Many of the cells treated with TPA became aggregated, attaching firmly to culture flasks. The average intracellular myeloperoxidase activity (EC 1.11.1.7) per cell decreased during induction of differentiation by TPA. It was also found that TPA enhanced, rather than inhibited, differentiation of HL-60 cells induced by DMSO. In addition to TPA, several polyfunctional diterpene esters of the tigliane, ingenane, and daphnane type have been tested for their ability to induce morphological and functional changes of HL-60 cells. The activities of the compounds to induce these changes correlated well with their activities as tumor promoters in two-step carcinogenesis in mouse skin. In particular, half the concentrations required for induction of adhesion of the cells to flasks were roughly correlated to the potency of these compounds as tumor promoters. Among the compounds tested, phorbol-12,13-didecanoate (PDD), ingenol-3-hexadecanoate, Pimelea factor P1 and Pimelea factor P2 were as active as TPA, while 4-O-methyl-TPA and 4 alpha-PDD were much less active. Phorbol and ingenol were totally inactive up to a concentrations 10,000-fold higher than that of TPA.
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PMID:Induction of differentiation in human promyelocytic leukemia cells by tumor promoters. 628 Dec 83

A method was devised to quantitate N-acetoxy-N-acetyl-2-aminofluorene (N-AcO-AAF) induced crosslinking of the ionic complex between [methyl-3H]thymidine labeled pBR322 DNA and lysozyme. This involved chromatography of the modified complex on Sephadex CM 25 with a high salt buffer that dissociated the non-covalently bound complex and permitted early elution of unbound [3H]DNA. The crosslinked complex was then eluted with buffer at pH 10.5. The amount of crosslinking was a function of the carcinogen concentration in the reaction mixture containing the complex. Addition of the spin trap nitrosobenzene or the radical trap 2,2-diphenyl-1-picrylhydrazyl to the complex prior to the addition of N-AcO-AAF decreased crosslinking. Reaction of the carcinogen with a solution of [methyl-3H]thymidine labeled Escherichia coli DNA led to the formation of tritiated water that was azeotropically distilled from the mixture. If nitrosobenzene was added prior to the carcinogen, the amount of tritium water released was depressed. Addition of N-AcO-AAF to a mixture of acrylamide and bisacrylamide increased its relative viscosity. Far u.v. irradiation of the complex or reacting it with ammonium persulfate that dissociates to the sulfate anion radical, SO(4), induced crosslinking. While these observations support a free radical mechanism for crosslinking, whether the free radicals arise from heterolytic or homolytic cleavage of N-AcO-AAF remains undetermined.
Carcinogenesis 1983
PMID:Evidence that N-acetoxy-N-acetyl-2-aminofluorene crosslinks DNA to protein by a free radical mechanism. 634 30

Human promyelocytic leukemia cells (HL-60) were induced to differentiate into macrophage-like cells in a dose-dependent manner by the tumor promoters phorbol-12-myristate-13-acetate and teleocidin, a non-phorbol ester promoter. An HL-60 cell variant, designated as R-59, which is resistant to differentiation induction by phorbol-12-myristate-13-acetate was also resistant to differentiation induction by teleocidin. Differentiation was determined by increases in the percent of morphologically mature cells and in lysozyme and nonspecific esterase activities. Both compounds inhibited the growth of HL-60 cells by blocking them from entering the synthesis phase of the cell cycle with an accumulation of cells after 48 h in G1 phase. No such effects were observed in the R-59 cells. They were, however, as susceptible as the parent HL-60 cells, to inducers which are not considered to be tumor promoters such as dimethylsulfoxide and retinoic acid. However, these inducers cause the HL-60 and R-59 cells to differentiate into granulocyte-like cells. These results indicate that teleocidin produces in both the HL-60 and R-59 cells effects which are similar to those cause by phorbol-12-myristate-13-acetate. The possibility that agents producing such effects in these two cell types may represent potential tumor promoters is discussed.
Carcinogenesis 1982
PMID:Induction of differentiation of human promyelocytic leukemia (HL-60) cells by teleocidin and phorbol-12-myristate-13-acetate. 680 9

Quantitative analysis of lysozyme- and CD68-positive Kupffer cells was carried out in connection with diethylnitrosamine-induced hepatocarcinogenesis in non-human primates. The number of Kupffer cells/mm2 was determined in 28 cases of hepatocellular carcinoma (HCC) and seven age-matched controls. The Kupffer cell counts (mean +/-SEM) gradually decreased in the following order, irrespective of the histochemical markers (lysozyme or CD 68) used: healthy control liver (101.7 +/- 13.5 and 103.2 +/- 11.9 respectively), non-cirrhotic and non-neoplastic host liver (54.3 +/- 13.6 and 50.5 +/- 15.4), cirrhotic host liver (26.2 +/- 8.2 and 27.2 +/- 3.3), HCC tissue (20.7 +/- 4.4 and 19.3 +/- 4.1) and metastatic foci in the lung (9.8 +/- 1.8 and 9.7 +/- 2.8). The difference between the normal liver and the non-neoplastic, non-cirrhotic portions of the HCC-bearing liver was significant (P < 0.05). A highly significant difference was found between the number of Kupffer cells found in healthy control or non-neoplastic liver and those found in HCC nodules (P < 0.0001 and P < 0.0005 respectively). The results obtained by hematoxylin and eosin staining and lysozyme/CD68 immunohistochemistry were highly similar, indicating that this decrease was attributable primarily to numeric loss of Kupffer cells. The results suggest that the reduction in the number of Kupffer cells in HCC is a constant feature of hepatocarcinogenesis not only in rodent models, but also in non-human primates.
Carcinogenesis 1995 Dec
PMID:Quantitative evaluation of lysozyme- and CD68-positive Kupffer cells in diethylnitrosamine-induced hepatocellular carcinomas in monkeys. 860 89

Muciphages are mucin-rich phagocytes believed to evolve as a result of the disruption of colorectal crypts. In a previous work we found, in rectal biopsies from patients with chronic ulcerative colitis, muciphages having not only mucin but also lysozyme, an enzyme with a potent antimicrobial activity. Recently we detected lysozyme-rich muciphages in the normal mucosa of the stalk of colonic adenomas. Filed hematoxylin and eosin (H&E)-stained sections from 30 consecutive colorectal adenomas with a stalk (lined by normal colorectal mucosa) were stained with PAS (for mucopolysaccharides), with CD68 (to label macrophages) and with lysozyme (Muramidase). Of the 30 adenomas, 16 (40%) showed muciphages in the mucosa of the stalk. Those muciphages were PAS- CD68- and lysozyme-positive. Although the significance of these findings remains elusive, it is conceivable that lysozyme-rich muciphages mirror increased cell destruction in colorectal adenomas with a high cell turnover. The possibility that lysozyme-rich muciphages surrounding adenomas are instrumental in a novel molecular mechanism of host defense, effective at the early stages of colorectal carcinogenesis, was also entertained. Such a mechanism would prevent the lateral expansion of the dysplastic epithelium of the adenoma into the surrounding normal mucosa of the stalk.
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PMID:Lysozyme-rich muciphages surrounding colorectal adenomas. 1201 65

Rat stomach carcinomas induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) are widely used as a model for differentiated-type human stomach carcinomas. Here, we analyzed expression profiles in five MNNG-induced rat stomach carcinomas by the high-density oligonucleotide microarray containing approximately 8000 probe sets. 244 and 208 genes were up- and down-regulated, respectively, by 3-fold and over in four or five carcinomas. Up-regulated genes included those involved in the extracellular matrix remodeling (i.e. Collagen types I, III, V, MMP3), immune response (i.e. lysozyme, complements) and in ossification (i.e. Osteoblast-specific factor). Genes down-regulated included those related to hydrocarbon metabolism (i.e. aldose A, aldehyde dehydrogenase), gastric juice (ion transporter genes) and mucous production (Mucin 5) and gastric hormones (gastrin and somatostatin). The expression profile of the MNNG-induced rat stomach carcinomas shared many features with human stomach carcinomas while cyclin D1 was down-regulated in rat stomach carcinomas but up-regulated in human stomach carcinomas. When the expression profile of the MNNG-induced rat stomach carcinomas was compared with those of two kinds of rat mammary carcinomas, only 13 genes were commonly altered. These results showed that MNNG-induced stomach carcinomas possessed infiltrating capacity and had lost differentiated phenotypes of the stomach, in the same way as human stomach carcinomas, and could be used as a good model for them from the viewpoint of molecular expression profile.
Carcinogenesis 2003 May
PMID:Global expression analysis of N-methyl-N'-nitro-N-nitrosoguanidine-induced rat stomach carcinomas using oligonucleotide microarrays. 1277 Oct 29

Colon cancers develop after accumulation of multiple genetic and epigenetic alterations in colon epithelial cells. To shed light on global changes in gene expression of colon cancers and to gain further insight into the molecular mechanisms underlying colon carcinogenesis, we have conducted a comprehensive microarray analysis of mRNA using a rat colon cancer model with the food-borne carcinogen, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). Of 8749 genes or ESTs on a high density oligonucleotide microarray, 27 and 46 were over- and underexpressed, respectively, by > or =3-fold in colon cancers in common in two rat strains with distinct susceptibility to PhIP carcinogenesis. For example, genes involved in inflammation and matrix proteases and a cell cycle regulator gene, cyclin D2, were highly expressed in colon cancers. In contrast, genes encoding structural proteins, muscle-related proteins, matrix-composing and mucin-like proteins were underexpressed. Interestingly, a subset of genes whose expression is characteristic of Paneth cells, i.e. the defensins and matrilysin, were highly overexpressed in colon cancers. The presence of defensin 3 and defensin 5 transcripts in cancer cells could also be confirmed by in situ mRNA hybridization. Furthermore, Alcian blue/periodic acid Schiff base (AB-PAS) staining and immunohistochemical analysis with an anti-lysozyme antibody demonstrated Paneth cells in the cancer tissues. AB-PAS-positive cells were also observed in high grade dysplastic aberrant crypt foci, which are considered to be preneoplastic lesions of the colon. Our results suggest that Paneth cell differentiation in colon epithelial cells could be an early morphological change in cryptic cells during colon carcinogenesis.
Carcinogenesis 2004 Aug
PMID:Global gene expression analysis of rat colon cancers induced by a food-borne carcinogen, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine. 1505 25

Cyclooxygenase-2 (Cox-2) is expressed predominantly by stromal cells in intestinal adenomas from the Apc(Min/+) mouse model of familial adenomatous polyposis. We investigated the mechanistic basis of stromal cell Cox-2 expression in Apc(Min/+) mouse adenomas, as well as Cox-2 expression and activity in histologically normal (HN) Apc(Min/+) mouse intestine, in order to gain further insights into regulation of Cox-2 as a potential chemoprevention target. Upregulation of Cox-2 in intestinal tumours is not an intrinsic feature of Apc(Min/+) macrophages as bone marrow-derived Apc(Min/+) macrophages did not exhibit an abnormality in Cox-2 expression or activity. Intestinal permeability to lactulose or mannitol was similar in Apc(Min/+) mice and wild-type littermates, implying that macrophage activation by luminal antigen is unlikely to explain stromal cell Cox-2 induction. Moreover, stromal cells exhibited differential expression of Cox-2 and inducible nitric oxide synthase, suggesting 'alternative' (M2) rather than 'classical' (M1) macrophage activation. Flow cytometric sorting of isolated stromal mononuclear cells (SMNCs), on the basis of M-lysozyme and specific macrophage marker expression, demonstrated that macrophages, neutrophils and non-myelomonocytic cells all contributed to lamina propria prostaglandin (PG) E(2) synthesis. However, the majority of PGE(2) synthesis by macrophages was via a Cox-2-dependent pathway compared with predominant Cox-1-derived PGE(2) production by non-myelomonocytic cells. SMNCs from HN Apc(Min/+) intestinal mucosa exhibited similar levels of Cox-2 mRNA and protein, but produced more Cox-2-derived PGE(2) than wild-type cells at 70 days of age. There was an age-dependent decline in PGE(2) synthesis by Apc(Min/+) SMNCs, despite tumour progression. These data suggest that other Cox-2-independent factors also control PGE(2) levels during Apc(Min/+) mouse intestinal tumorigenesis. Regulation of macrophage Cox-2 expression and other steps in PGE(2) synthesis (e.g. PGE synthase) are valid targets for novel chemoprevention strategies that could minimize or avoid systemic COX-2 inhibition.
Carcinogenesis 2006 Mar
PMID:Regulation of stromal cell cyclooxygenase-2 in the ApcMin/+ mouse model of intestinal tumorigenesis. 1621 37


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