Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P17931 (galectin-3)
 2,860 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A purified lectin (MLI) from Viscum album was used to test whether peripheral monocytes from human blood can be activated for the production of tumour necrosis factor (TNF). Cytotoxic activity was detected in the supernatant of MLI-stimulated monocyte cultures. This cytotoxic activity was completely inhibited by monoclonal antibodies to TNF alpha. Small amounts of soluble TNF protein were measured in a TNF alpha-specific enzyme-linked immunospecific assay system. Strong expression of TNF alpha mRNA was induced in human monocytes as well as in macrophage cultures from C3H/HeJ mice having a low response to endotoxin after 2 h of stimulation. Both chains of the MLI were found to induce TNF mRNA equally well in human monocytes. In macrophages of endotoxin-low-responder mice the toxic A chain was a better inducer of TNF mRNA than the galactose-specific lectin B chain. Thus, MLI has immunomodulating effects in activating monocytes/macrophages for inflammatory responses.
Cancer Immunol Immunother 1991
PMID:Induction of tumor necrosis factor expression by a lectin from Viscum album. 204 82

We report the complete primary and secondary structures of a metastasis-associated Mr 34,000 galactoside-binding lectin. The polypeptide sequence (264 amino acids) was derived from the nucleotide sequence of three overlapping complementary DNA clones isolated from lambda gt11 and lambda gt10 phage libraries of UV-induced murine fibrosarcomas. Striking features of the polypeptide sequence are two distinct regions of beta-sheet and globular structures at the amino and carboxy terminals, respectively. Homology search suggests that the polypeptide is a chimeric gene product formed by fusion of the 5'-end of an Mr approximately 14,000 galactoside-binding lectin with an internal domain of the collagen alpha gene. Enzymatic treatment with collagenase confirmed the presence of a collagen-like structure in the polypeptide. Unexpectedly, the entire sequence is greater than 85% homologous to a rat low affinity IgE-binding protein.
Cancer Res 1989 Jul 01
PMID:Identification of the metastasis-associated, galactoside-binding lectin as a chimeric gene product with homology to an IgE-binding protein. 252 69

A galactose-specific lectin, recently described by our laboratory, is immunologically demonstrable on the surface of neoplastic cells derived from patients with Hodgkin's disease. This Hodgkin's lectin is shown to be functionally and antigenically related to the galactose-N-acetylgalactosamine-specific lectin of the hepatocyte (HBP). Poly- and monoclonal antibodies against either the cytoplasmic tail or the cell-surface binding site of HBP recognize the Hodgkin's lectin as a 55 Kd protein. Expression of the 55 Kd antigen appears to be restricted to Hodgkin's disease involved tissues and cells of the monocyte/macrophage lineage. The putative identification of the Hodgkin's lectin as an ectosialyltransferase unique to Hodgkin's cells is supported by inhibition of enzymatic activity by anti-HBP antibodies. Cultured Hodgkin's cells, in analogy to purified HBP, agglutinate T-lymphocytes mediated by the Hodgkin's lectin. This cell-to-cell interaction results in the incorporation of sialic acid into lymphocyte surface asialoglycans as well as in the stimulation of lymphocyte proliferation. The function of the Hodgkin's lectin as lymphocyte agglutinant in vitro suggests its role as an immunomodulator contributing to the immunodeficiencies associated with Hodgkin's disease.
Recent Results Cancer Res 1989
PMID:A marker and putative pathoantigen of Hodgkin's cells. 269 Feb 34

Polysaccharides are possibly involved in the pharmacological effects of Viscum album (mistletoe) extracts, which are used in cancer therapy. Therefore the water-soluble polysaccharides of the fresh plant and the fermented proprietary preparation Iscador were isolated and characterized inter alia by methylation analysis, partial hydrolysis and C-13-NMR spectroscopy. The main polysaccharide of the green parts of Viscum is a highly esterified galacturonan whereas in Viscum 'berries' a complex arabinogalactan is predominant. Both types of these constituents were found in Iscador but with definite changes in molecular weight and structure. An interaction between the arabinogalactan and the galactose-specific lectin (ML I) in Viscum could be demonstrated. In three immunological tests (granulocyte, chemiluminescence, carbon clearance test) the polysaccharides failed to increase phagocytic activity of granulocytes and macrophages.
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PMID:Structure and properties of polysaccharides from Viscum album (L.). 380 77

Galectin-3 (Gal-3) is a beta-galactoside-binding protein with M(r) approximately 30,000. Cell surface Gal-3 is postulated to be involved in homotypic aggregation of tumor cells in the circulation during metastasis through attachment to a complementary serum glycoprotein(s), which serves as a cross-linking bridge between adjacent cells. To test this hypothesis a recombinant strain of baculovirus encoding Gal-3 was used to infect Sf9 insect cells, which lack endogenous Gal-3. Immunoblotting and indirect immunofluorescence studies revealed that the infection with recombinant virus conferred Gal-3 expression on Sf9 cells, and the Gal-3 was localized on the cell surface as well as in the cytoplasm. Sf9 cells infected with recombinant virus underwent homotypic aggregation in the presence of exogenous glycoprotein (i.e., asialofetuin), whereas control cells uninfected or infected with wild-type virus did not. Lactose and Fab' fragments of anti-Gal-3 antibodies markedly inhibited the cell-cell aggregation. Moreover, cosuspension of Sf9 cells infected with the recombinant virus with uninfected cells in the presence of asialofetuin resulted in a preferential cell-cell adhesion of the Gal-3-expressing cells. These results directly demonstrate the ability of cell surface Gal-3 molecules to mediate homotypic cell adhesion by bridging through branched, soluble complementary glycoconjugates.
Cancer Res 1995 Aug 01
PMID:Functional evidence that cell surface galectin-3 mediates homotypic cell adhesion. 754 67

Extracts from mistletoe enjoy a large popularity in central Europe as an unconventional treatment modality for cancer, warranting scientific efforts with defined components to delineate any potential benefit. The galactose-specific lectin from Viscum album (VAA), known to exhibit immunomodulatory and ensuing antitumoral capacities in animal model systems, was shown to aggregate human blood cells in the following order: neutrophils, mononuclear cells--thrombocytes and erythrocytes. To contribute to the analysis of lectin effects on individual aspects of the host defence system, two parameters of neutrophils were quantitatively assessed, namely the aggregating activity of VAA as a measure of strength of interaction with cell surface ligands and the effect of lectin on oxidative metabolism (H2O2 release) of these cells. It was found that whole lectin and its carbohydrate-binding B-subunit possessed the capacity to induce cell aggregation and H2O2 release, which were blocked by D-galactose and lactose. Both effects displayed similar dependence on the lectin concentration in the range 0.1-25 micrograms/ml. The toxic A-subunit displayed detectable activity only in high doses (50 micrograms/ml) while the bovine heart galaptin (14 kDa; galectin-1) failed to affect neutrophils. The role of oxidative metabolism in regulation of neutrophil aggregation induced by VAA was studied using metabolic inhibitors and controlled heating at 46 degrees C leading to inhibition of plasma membrane NADPH-oxidase system. Trifluoperazine and menadione inhibited the neutrophil aggregation in a dose-dependent manner in comparison with such inhibitors as amiloride and theophylline.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Viscum album agglutinin-induced aggregation of blood cells and the lectin effects on neutrophil function. 764 87

Carcinoma of the thyroid gland, the most frequently diagnosed endocrine malignancy, is often associated with early regional metastases. With the exception of papillary carcinoma, distinguishing benign from malignant thyroid neoplasms in the absence of metastatic disease is difficult. Recently, the vertebrate lectins galectin-1 and galectin-3 have been implicated in the regulation of cellular growth, differentiation, and malignant transformation of a variety of tissues. To determine whether these galectins have a role in thyroid neoplasia, we analyzed 32 specimens from thyroid malignancies (16 papillary, 7 follicular, 8 medullary carcinomas, and 1 metastasis to lymph node), 10 benign thyroid adenomas, 1 nodular goiter, and 33 specimens from adjacent normal thyroid tissue for the expression of galectin-1 and galectin-3 with immunohistochemical and immunoblotting techniques utilizing anti-galectin antibodies. All thyroid malignancies of epithelial origin (ie, papillary and follicular carcinomas) and a metastatic lymph node from a papillary carcinoma expressed high levels of both galectin-1 and galectin-3. The medullary thyroid carcinomas, which are of parafollicular C cell origin, showed a weaker and variable expression of these galectins. In contrast, neither benign thyroid adenomas nor adjacent normal thyroid tissue expressed galectin-1 or galectin-3. These results suggest that galectin-1 and galectin-3 may be associated with malignant transformation of thyroid epithelium and may potentially serve as markers for distinguishing benign thyroid adenomas from differentiated thyroid carcinomas.
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PMID:Differential expression of galectin-1 and galectin-3 in thyroid tumors. Potential diagnostic implications. 767 93

The Mac-2 lectin (carbohydrate binding protein 35) is a soluble, 32- to 35-kDa phosphoprotein that binds galactose-containing glycoconjugates. We report here that the colonic epithelium is a major site of Mac-2 expression in vivo based on immunohistochemistry of human tissue specimens. In this epithelium, proliferating cells at the base of the crypts do not express Mac-2 but its expression increases with differentiation along the crypt-to-surface axis. Mac-2 expression is concentrated in the nuclei of these differentiated epithelial cells. The progression from normal mucosa to adenoma to carcinoma is associated with significant changes in Mac-2 nuclear localization and expression. In all adenomas (9/9) and carcinomas (13/13) examined, Mac-2 was not present in the nucleus but was localized in the cytoplasm. Sequencing of Mac-2 cDNAs from normal mucosa and carcinoma revealed no specific mutations that could account for this loss of nuclear localization. We also observed a 5- to 10-fold decrease in Mac-2 mRNA levels in cancer compared to normal mucosa as well as a significant reduction in the amount of Mac-2 protein expressed. These observations suggest that Mac-2 exclusion from the nucleus and its decreased expression may be related to the neoplastic progression of colon cancer.
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PMID:Decreased expression of Mac-2 (carbohydrate binding protein 35) and loss of its nuclear localization are associated with the neoplastic progression of colon carcinoma. 768 4

Citrus pectin (CP) and pH-modified citrus pectin (MCP) are highly branched and non-branched complex polysaccharides, respectively, rich in galactoside residues, capable of combining with the carbohydrate-binding domain of galectin-3. We reported previously that intravenous injection of B16-F1 murine melanoma cells with CP or MCP into syngeneic mice resulted in a significant increase or decrease of lung colonization, respectively (Platt D, Raz A (1992) J Natl Cancer Inst 84:438-42). Here we studied the effects of these polysaccharides on cell-cell and cell-matrix interactions mediated by carbohydrate-recognition. MCP, but not CP, inhibited B16-F1 melanoma cells adhesion to laminin and asialofetuin-induced homotypic aggregation. Both polysaccharides inhibited anchorage-independent growth of B16-F1 cells in semisolid medium, i.e. agarose. These results indicate that carbohydrate-recognition by cell surface galectin-3 may be involved in cell-extracellular matrix interaction and play a role in anchorage-independent growth as well as the in vivo embolization of tumour cells.
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PMID:Effects of natural complex carbohydrate (citrus pectin) on murine melanoma cell properties related to galectin-3 functions. 769 55

Galectin-1 and galectin-3, galactoside-binding lectins with molecular weights of M(r) 14,500 and 31,000, respectively, are expressed in normal and malignant cells and have been implicated in regulation of cell growth, adhesion, and metastasis. We analyzed the expression of galectins in 21 cultured human colon carcinoma cell lines by immunoblotting. Galectin-1 was detected in only 7, whereas galectin-3 was found in 20 of the cell lines. KM12 cells, which express only galectin-3, were used to isolate this lectin by affinity chromatography, and the purified lectin was used to identify complementary glycoconjugates by blotting. Galectin-3 was shown to bind to human laminin, carcinoembryonic antigen, and lysosome-associated membrane glycoproteins, which are involved in cell adhesion. Galectin-3 was localized on the KM12 cell surface and colocalized with carcinoembryonic antigen. Several endogenous glycoproteins and cell surface proteins of molecular weights in the range M(r) 58,000 to > 200,000, including carcinoembryonic antigen and lysosome-associated membrane glycoproteins, were identified as galectin-3 ligands by coimmunoprecipitation with and affinity chromatography on immobilized galectin-3. These data demonstrate that galectin-3 interacts with several adhesion molecules and suggest that this lectin may have a role in human colon carcinoma cell adhesion.
Cancer Res 1995 May 15
PMID:Carcinoembryonic antigen and other glycoconjugates act as ligands for galectin-3 in human colon carcinoma cells. 774 23


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