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)

The high affinity 67-kDa laminin receptor (67LR) is highly expressed in metastatically active human cancers. A 37-kDa polypeptide has been identified as its precursor (37LRP). Antibodies raised against 37LRP-derived synthetic peptides were used in immunogold electron microscopy and immunoblot studies to assess the effect of laminin on expression of the 67LR and the 37LRP. Laminin (15 micrograms/ml) treatment of suspended A2058 human melanoma cells doubled the expression of both 37LRP and the 67LR. Fibronectin had no effect. There was no effect of laminin on the expression of actin or galectin-3. Cycloheximide treatment of cells prior to laminin abrogated its inducible effect. The results suggest that binding of laminin by cell surface laminin receptors induces synthesis of the 37LRP and mature 67LR, with a consequent delivery to the cell surface of more laminin binding proteins for potentiated attachment of the melanoma cell to the basement membrane during invasion and metastasis.
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PMID:Protein synthesis is required for laminin-induced expression of the 67-kDa laminin receptor and its 37-kDa precursor. 769 18

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

The Mac-2 protein is a lectin specific for galactose-containing glycoconjugates. Present in some normal cells, it was also associated with the metastatic potential of some carcinoma cells. We studied Mac-2 expression in three human melanoma cell lines and in five variants and clones from one of them. By using the M3/38 rat monoclonal antibody, Mac-2 was demonstrated on cell surface by flow cytometry as well as in the cytoplasm and in the nucleus by confocal microscopy. The expression of Mac-2 was not correlated with that of terminal unsialylated Gal beta 1-3 GalNac structures on metastatic melanoma cell lines. However, the presence of extracellular Mac-2 containing vesicles was observed in cell lines with metastatic potency. Western blot analysis of cell lysates, in reducing or non-reducing conditions, revealed two bands of 34-36 and 93-98 kDa apparent M(r), also found in HL60 and P388.D1 cell lines used as positive controls.
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PMID:Expression of the galactose binding protein Mac-2 by human melanoma cell-lines. 801 32

The endogenous human tumor-associated galectin-3 (hL-31) is a functional molecule which acts as a receptor for ligands containing poly-N-acetyllactosamine sequences. However, little is known about its native ligand(s). In order to identify the ligand(s), the human melanoma cell line A375 was metabolically labeled with [3H]glucosamine, and total cell extracts and serum-free conditioned medium of the labeled cells were affinity-purified on immobilized recombinant hL-31 followed by elution with lactose, the specific sugar inhibitor of the lectin. Cellular ligands for hL-31 were found to be composed of the two lysosome-associated membrane proteins, LAMP-1 and LAMP-2, while secreted ligands consisted of two glycoproteins of 98 and 70 kDa. N-terminal protein microsequencing revealed that the 98 kDa and 70 kDa species share the same N-terminal sequence. The functional relevance of these secreted ligands was demonstrated by their ability to inhibit lectin-mediated hemagglutination in a manner similar to the specific sugar inhibitor lactose. Computer-assisted sequence library searches have identified the 98 kDa human melanoma secreted ligand to be the Mac-2-binding protein (Mac-2-BP), also known as the human lung tumor L3 antigen.
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PMID:Identification of human melanoma cellular and secreted ligands for galectin-3. 802 81

Lewis lung (3LL) peritoneal carcinomatosis elicits a complex host response in the peritoneal compartment. The response was delayed, showing few inflammatory cells through day 6 after lethal challenge with 3LL cells. Responses began in about half the mice on day 7 and had appeared in all mice by day 11. On day 7, some mice still showed no detectable 3LL growth in the pertioneal lavage fluid, and no differences in the peritoneal cell populations as compared with the control group. Other tumor-bearing mice, however, had evidence of 3LL cells and hemorrhagic ascites in the peritoneal compartment, with increased numbers of peritoneal macrophages (PM) and polymorphonuclear neutrophils (PMN). By day 11, all tumor-bearing mice had 3LL growth and hemorrhagic ascites. On days 7-11, there was a major influx of macrophages with a later influx of PMN between days 11 and 14. Two distinct PM populations were detected on day 7 in mice that showed detectable 3LL peritoneal carcinomatosis: resident PM, which did not express the Mac-2 antigen, and recruited PM, which were Mac-2+. At least some resident PM remained in the peritoneal compartment through day 14. Analysis of the kinetics of the cytotoxic capabilities of PM from tumor-bearing mice showed that by day 7 macrophages were able to kill the B16 melanoma tumor target, but not the 3LL target. The PM, however, were able to be activated further to kill the 3LL target by treatment in vitro with lipopolysaccharide and interferon gamma. No inhibition of PM tumoricidal activity could detected in the peritoneal wash of tumor-bearing mice. A lack of activation of PM from 3LL tumor-bearing mice may be involved in progression of peritoneal carcinomatosis.
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PMID:Role of macrophages in the host response to Lewis lung peritoneal carcinomatosis. 816 18

Galectin-3 is a laminin binding protein which expression is altered in a variety of human carcinomas including colon, breast and endometrium. In these tumors, we consistently observed a down regulation of galectin-3 expression related to increased aggressiveness. Galectin-3 belongs to a family of galactose-binding lectins and binds laminin through its numerous poly-N-acetyllactosamine chains. To date, the exact role of galectin-3 in the complex interactions between cancer cells and laminin has not been clearly defined. Adhesion of melanoma cells to laminin is a critical event during tumor invasion and metastasis. In this study, we explore the possibility that galectin-3 could modulate attachment of two human melanoma cell lines to laminin. A2058 and A375 melanoma cell expressed galectin-3 on their surface as demonstrated by immunofluorescence, and attached to laminin in an in vitro assay. We demonstrate that neither recombinant galectin-3 nor an affinity purified antigalectin-3 antiserum altered adhesion of A2058 or A375 melanoma cells to laminin. Our data strongly suggest that galectin-3 is not a key element in adhesion of the melanoma cells to laminin. These results are not surprising in light of the observation that galectin-3 expression is down regulated in cancer and that increased adhesion to laminin is a constant feature of invasive cancer cells.
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PMID:Galectin-3, a laminin binding protein, fails to modulate adhesion of human melanoma cells to laminin. 855 98

Lysosomal-membrane-associated glycoproteins (Lamps) 1 and 2 are rarely found on the plasma membranes of normal cells. There is evidence suggesting an increase in their cell-surface expression in tumor cells, with some data indicating that the adhesion of some cancer cells to the extracellular matrix is partly mediated by interactions between Lamps and E-selectin and between Lamps and galectins (endogenous-galactoside-binding lectins). The present study examined the expression of Lamp-1 and Lamp-2 and their interactions with galectin-3 in different human tumor cell lines. Indirect immunofluorescence staining revealed accumulation of Lamp molecules at the edges of A2058 human metastasizing melanoma cells suggesting that these glycoproteins could participate in cell adhesion. Flow cytometry showed the presence of cell-surface Lamps in A2058, HT1080 (human fibrosarcoma) and CaCo-2 (human colon-adenocarcinoma) cells. Treatment with 2 mM sodium butyrate for 24 and 48 hr resulted in a significant increase in Lamps surface expression. A strong binding of A2058 to recombinant galectin-3 was detected by FACS. The application of 2 and 5 mM butyrate for the same incubation period enhanced galectin-3 binding to Lamps-expressing cells. Our results support the idea that Lamps may be considered a new family of adhesive glycoproteins participating in the complex process of tumor invasion and metastasis.
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PMID:Expression of Lamp-1 and Lamp-2 and their interactions with galectin-3 in human tumor cells. 942 97

Reactivity of the N-acetylgalactosamine-binding Helix pomatia agglutinin (HPA) in tumours has been associated with poor prognosis and metastasis development. In our LOX/FEMX-I human melanoma model, the binding of HPA correlates with experimental lung metastasis formation in athymic nude mice. In the present study, the metastatic potential of 2 human melanoma cell lines (LOX and FEMX-I) was assessed in relation to carbohydrate and invasive phenotype. Immunocytological and invasion assays highlighted significant differences between these 2 cell lines. Immuno-cytochemical analysis confirmed the widespread expression of HPA-binding glycoconjugates on LOX but not FEMX-I cells. One of these HPA-binding glycoconjugates, the Tn antigen, was expressed highly on the surface of LOX cells but only weakly in the cytoplasm of FEMX-I cells. The sialyl Tn antigen was expressed in FEMX-I but not in LOX cells. There was no difference between the cell lines in adhesion/rate of trapping in athymic nude mouse lung tissues. In Matrigel invasion assays, LOX cells demonstrated an invasion potential more than 6 times greater than that observed with FEMX-I cells. Matrigel invasion of LOX cells was inhibited after incubation with HPA (89%) compared to controls with HPA and GalNAc blocking sugar or without HPA (p < 0.0005 at 5 df). In contrast, there was no inhibitory effect with the anti-Tn antibody IE3. Invasion of FEMX-I cells was not affected by the lectin and the IE3 antibody. Immuno-cytochemical analysis revealed expression of the terminal galactose- and polylactosamine-binding lectin galectin 3 (Mac-2) in these melanoma cell lines. Expression of both the lectin and its receptor may be a contributory feature in the pulmonary invasion of LOX melanoma cells. Overall, our findings suggest that HPA-binding glycoconjugates other than the alphaGalNAc-O-Ser/Thr of the Tn antigen may be important in the extracellular matrix invasion of LOX melanoma cells.
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PMID:Invasion potential and N-acetylgalactosamine expression in a human melanoma model. 946 64

Tumor cell adhesion and migration to laminin are important events during invasion and metastatic spread. Galectin-3, a multifunctional member of the galectin family, binds specifically the poly-N-acetyllactosamine residues of laminin and has been implicated in tumor invasion and metastasis. Galectin-3 is multimerized by transglutaminase, an enzyme that catalyzes cross-linking between glutamine and other aminoacid residues. In this study, we examined the consequences of transglutaminase-mediated galectin-3 oligomerization on the interactions between cancer cells and laminin. We first demonstrated that human galectin-3 is cross-linked by guinea pig liver transglutaminase, forms oligomers, and incorporates the marker 5-(biotinamido) pentylamine. Expression of transglutaminase activity in the A375 and A2058 human melanoma cell extracts was revealed by its ability to induce galectin-3 oligomerization and 5-(biotinamido) pentylamine incorporation. Transglutaminase-treated galectin-3 did not affect adhesion or migration of the melanoma cells to laminin but consistently induced a significant increase of the percentage of cell spreading compared to the control (23.5 +/- 2.3%, vs. 10.6 +/- 1.9% at 180 min, p < 0.05), or to untreated galectin-3 or transglutaminase alone. Our study is the first demonstration that human galectin-3 is oligomerized by transglutaminase with, as a consequence, a specific effect of melanoma cell spreading on laminin. This phenomenon could be of significance in the modulation of cancer cell interactions with laminin during tumor invasion and metastasis.
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PMID:Transglutaminase-mediated oligomerization of galectin-3 modulates human melanoma cell interactions with laminin. 979 24

Galectin-3, a member of the beta-galactoside-binding animal lectins, has been implicated in tumor invasion and metastasis. Using an immunoligand assay, we assessed the circulating levels of galectin-3 in sera from cancer patients as well as from healthy controls. Low serum levels of galectin-3 were detected in healthy individuals (median, 62 ng/ml; range, 20-313 ng/ml; 95th percentile, 184.3 ng/ml). Compared with healthy individuals, galectin-3 serum levels in patients with breast, gastrointestinal, lung, or ovarian cancer, melanoma, and non-Hodgkin's lymphoma were significantly elevated (P = 0.014). Moreover, galectin-3 concentrations in sera from patients with metastatic disease were higher than in sera from patients with localized tumors. Maximum serum concentrations of galectin-3 (median, 320 ng/ml; range, 20-950 ng/ml) were found in patients with metastatic gastrointestinal carcinoma. These results suggest that circulating galectin-3 may play a role in tumor progression. The possibility of using this assay in early-stage cancer to predict metastasis should be studied.
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PMID:Concentrations of galectin-3 in the sera of normal controls and cancer patients. 1077 68


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