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Query: UNIPROT:P17931 (
galectin-3
)
2,860
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The expression pattern of
galectin-1
and
galectin-3
in the human olfactory epithelium was investigated in relation to olfactory marker protein (OMP) using confocal laser immunofluorescence in human specimens and postmortem biopsies. OMP expression was found in olfactory receptor neurons (ORNs) in the olfactory mucosa and in fibers of the olfactory nerve crossing the submucous connective tissue. Galectin-1 was expressed in both the connective tissue of the nasal cavity and in the basal layer of the olfactory epithelium. In contrast,
galectin-3
expression was limited to cells of the upper one-third of the olfactory epithelium. Expression of
galectin-3
occurred in a subset of OMP-positive cells. However, between areas of
galectin-1
and
galectin-3
expression in the lower and upper portion of the epithelium, OMP-positive ORNs did not stain for both galectins. Considering the potential role of
galectin-1
and
galectin-3
in cell differentiation and maturation, the differential localization of galectins in the olfactory epithelium appears to be consistent with a significant role of these molecules in the physiological turnover of ORNs.
...
PMID:Immunohistochemical distribution of galectin-1, galectin-3, and olfactory marker protein in human olfactory epithelium. 1081 79
Both the ability of malignant cells to form multicellular aggregates via homotypic or heterotypic aggregation and their adhesion to the endothelium are important if not critical during early stages of cancer metastasis. The tumor-associated carbohydrate Thomsen-Friedenreich antigen (T antigen) and beta-galactoside binding lectins (galectins) have been implicated in tumor cell adhesion and tissue invasion. In this study, we demonstrate the involvement of T antigen in both homotypic aggregation of MDA-MB-435 human breast carcinoma cells and their adhesion to the endothelium. The T antigen-specific peptide P-30 (HGRFILPWWYAFSPS) selected from a bacteriophage display library was able to inhibit spontaneous homotypic aggregation of MDA-MB-435 cells up to 74% in a dose-dependent manner. Because T antigen has beta-galactose as a terminal sugar, the expression profile of beta-galactoside-binding lectins (galectins) in MDA-MB-435 cells was studied. Our data indicated the abundant expression of [35S]methionine/cysteine-labeled
galectin-1
and
galectin-3
in this cell line, which suggested possible interactions between galectins and T antigen. As revealed by laser confocal microscopy, both
galectin-1
and
galectin-3
also participate in the adhesion of the MDA-MB-435 cells to the endothelium. We observed the clustering of
galectin-3
on endothelial cells at the sites of the contact with tumor cells, consistent with its possible interaction with T antigen on cancer cells The
galectin-1
signal, however, strongly accumulated at the sites of cell-cell contacts predominantly on tumor cells. The T antigen-specific P-30 significantly (50%) inhibited this adhesion, which indicated that T antigen participates in the adhesion of MDA-MB-435 breast cancer cells to the endothelium. The ability of synthetic P-30 to inhibit both the spontaneous homotypic aggregation of MDA-MB-435 cells and their adhesion to the endothelium (>70 and 50%, respectively) suggests its potential functional significance for antiadhesive therapy of cancer metastasis.
...
PMID:Effects of Thomsen-Friedenreich antigen-specific peptide P-30 on beta-galactoside-mediated homotypic aggregation and adhesion to the endothelium of MDA-MB-435 human breast carcinoma cells. 1082 25
The interaction of cells with the extracellular matrix regulates cell adhesion, motility, growth, survival and differentiation through integrin-mediated signal transduction. Here we demonstrate that galectin-8, a secreted mammalian (beta)-galactoside binding protein, inhibits adhesion of human carcinoma (1299) cells to plates coated with integrin ligands, and induces cell apoptosis. Pretreatment of the cells with Mn(2+), which increases the affinity of integrins for their ligands, abolished the inhibitory effects of galectin-8. The inhibitory effects of galectin-8 were specific and were not mimicked by plant lectins or other galectins (
galectin-1
and
galectin-3
). In accordance with its anti-adhesive effects, transfection of galectin-8 cDNA into 1299 cells significantly reduced (by 75%) colony formation, when compared to the number of colonies formed by cells transfected with an empty vector. Affinity chromatography over immobilized galectin-8 indicated that few membrane proteins interacted with galectin-8 in a sugar-dependent manner. Microsequencing and western immunoblotting revealed that (alpha)(3)(beta)(1 )integrin derived from 1299 as well as other cells (e.g. HeLa and human endothelial cells) is a major galectin-8 binding-protein. Furthermore, immunoprecipitation and immunohistochemical studies suggested that endogenous galectin-8, secreted from 1299 cells, forms complexes with (alpha)(3)(beta)(1) integrins expressed on the surface of 1299 cells. Galectin-8 also interacts with other members of the integrin family, like (alpha)(6)(beta)(1 )integrins. In contrast, galectin-8 only minimally interacts with (alpha)(4 )or (beta)(3 )integrins. We propose that galectin-8 is an integrin binding-protein that interacts to a different extent with several, but not all members of the integrin family. Binding of galectin-8 modulates integrin interactions with the extracellular matrix and thus regulates cell adhesion and cell survival.
...
PMID:Galectin-8 binding to integrins inhibits cell adhesion and induces apoptosis. 1085 18
The subcellular plurilocalization of some lectins (
galectin-1
,
galectin-3
, galectin-10, calreticulin, etc.) is an intriguing problem, implying different partners according to their localization, and involvement in a variety of cellular activities. For example, the well-known lectin,
galectin-3
, a lactose-binding protein, can act inside the nucleus in splicing events, and at the plasma membrane in adhesion, and it was demonstrated that
galectin-3
interacts in the cytoplasm with Bcl-2, an antiapoptotic protein. Some years ago, our group isolated a nuclear lectin CBP70, capable of recognizing N-acetylglucosamine residues. This lectin, first isolated from the nucleus of HL60 cells, was also localized in the cytoplasm. It has been demonstrated that CBP70 is a glycosylated lectin, with different types of glycosylation, comparing cytoplasmic and nuclear forms. In this article, we have studied the localization of CBP70 in undifferentiated HL60 cells by electron microscopy, immunofluorescence analysis, and subcellular fractionation. The results obtained clearly demonstrated that CBP70 is a plurilocalized lectin that is found in the nucleus, at the endoplasmic reticulum, the Golgi apparatus, and mitochondria, but not at the plasma membrane. Because CBP70, a nuclear glycoprotein, was found to be associated also with the endoplasmic reticulum and the Golgi apparatus where the glycosylation take place, it raised the question: where does the glycosylation of nuclear proteins occur?
...
PMID:Glycosylated nuclear lectin CBP70 also associated with endoplasmic reticulum and the Golgi apparatus: does the "classic pathway" of glycosylation also apply to nuclear glycoproteins? 1086 61
Galectins are a family of non-integrin beta-galactosidase-binding lectins. Altered expression of galectins has been associated with neoplastic transformation and progression in several human tumors. In this study, we examined the distribution patterns of
galectin-1
and
galectin-3
in normal (n=45), benign (n=16), and malignant (n=49) salivary gland specimens using immunohistochemistry to determine their diagnostic and/or biological implications in salivary gland tumorigenesis. In normal salivary glands,
galectin-3
expression was limited to ductal cells, and
galectin-1
was usually faintly detected in ductal cells and strongly positive in myoepithelial cells. In benign tumors,
galectin-3
maintained the ductal localization, but
galectin-1
showed variable expression in ductal and myoepithelial cells. In malignant tumors, most of the polymorphous low-grade adenocarcinomas and carcinoma ex-pleomorphic adenomas expressed both galectins, whereas adenoid cystic and acinic cell carcinomas showed dramatically reduced
galectin-3
expression and heterogeneous galactin-1 staining. Our data demonstrated altered localization and expression of
galectin-3
, and to lesser extent,
galectin-1
in salivary gland carcinomas. These findings may assist in the differential diagnosis of some salivary gland malignancies, especially when using small and limited fine-needle aspiration materials.
...
PMID:Differential expression of galectin-1 and galectin-3 in benign and malignant salivary gland neoplasms. 1089 35
Galectin-1 and
galectin-3
have important functions in cell-cell interactions, cell adhesion to extracellular matrix, the organization of extracellular matrix, and tissue remodeling. To assess their potential role in chronic pancreatitis (CP), we examined their expression by Northern blot analysis, in situ hybridization, immunohistochemistry, and Western blot analysis in normal and CP pancreatic tissues. Northern blot analysis revealed a 4.5-fold increase of
galectin-1
mRNA (p < 0.01) and a 3.8-fold increase of
galectin-3
mRNA (p < 0.01) in CP samples compared with normal controls. In situ hybridization analysis of normal pancreas indicated low abundance of
galectin-1
mRNA in fibroblasts, whereas
galectin-3
mRNA was moderately present in ductal cells. CP samples exhibited moderate to intense
galectin-1
mRNA signals in fibroblasts, whereas
galectin-3
mRNA signals were intense in the cells of ductular complexes and weak in the degenerating acinar cells. In addition, intense
galectin-1
and
galectin-3
mRNA signals were present in nerves of normal and CP samples. Immunohistochemistry showed a distribution pattern of
galectin-1
and
galectin-3
similar to that described for in situ hybridization. Relative quantification of
galectin-1
and
galectin-3
protein by immunoblotting revealed an increase of 3.2-fold and 3.0-fold, respectively, in CP compared with normal controls. There was a significant correlation between
galectin-1
and fibrosis and between
galectin-3
and fibrosis and the density of ductular complexes. Up-regulation of
galectin-1
in fibroblasts and
galectin-3
in ductular complexes suggests a role of these lectins in tissue remodeling in CP. Galectin-1 might participate in ECM changes, whereas
galectin-3
seems to be involved in both ECM changes and ductular complex formation.
...
PMID:Galectin-1 and galectin-3 in chronic pancreatitis. 1095 Jan 14
Langerhans cells are dendritic antigen-presenting cells residing predominantly in the epidermis. Since endogenous galactoside-binding lectins with the jelly-roll motif (galectins) are known to trigger cellular responses, including mediator release, we investigated by lectin histochemistry the cells' capacity to bind two common members of this family, i.e.
galectin-1
and -3. Actually, surrounding keratinocytes express a high level of
galectin-3
, and these cells can be considered as donors of this lectin to Langerhans cells. Employing biotinylated
galectin-1
and -3, and concomitantly an antibody against CD1a as a second marker, to visualize the position of Langerhans cells in the human epidermis, the expression of
galectin-3
-reactive glycoligands in contrast to the lack of binding of
galectin-1
was observed. Although the functional consequences of this selectivity are unclear, these results reveal an example for differential cellular reactivity towards two related endogenous lectins.
...
PMID:Human epidermal Langerhans cells are selectively recognized by galectin-3 but not by galectin-1. 1105 99
Galectins, a family of mammalian lectins with specificity to beta-galactosides, are involved in growth-regulatory mechanisms and cell adhesion. A relationship is assumed to exist between the levels of expression of galectins and the level of malignancy in human gliomas. A comparative study of this aspect in the same series of clinical samples is required to prove this hypothesis. Using computer-assisted microscopy, we quantitatively characterized by immunohistochemistry the levels of expression of galectins-1, -3 and -8 in 116 human astrocytic tumors of grades I to IV. Extent of transcription of galectins-1, -3, and -8 genes was investigated in 8 human glioblastoma cell lines by means of RT-PCR techniques. Three of these cell lines were grafted into the brains of nude mice in order to characterize in vivo the galectins-1, -3 and -8 expression in relation to the patterns of the tumor invasion of the brain. The role of
galectin-1
, -3 and -8 in tumor astrocyte migration was quantitatively determined in vitro by means of computer-assisted phase-contrast videomicroscopy. The data indicate that the levels of
galectin-1
and
galectin-3
expression significantly change during the progression of malignancy in human astrocytic tumors, while that of galectin-8 remains unchanged. These three galectins are involved in tumor astrocyte invasion of the brain parenchyma since their levels of expression are higher in the invasive parts of xenografted glioblastomas than in their less invasive parts.
Galectin-3
,
galectin-1
, and to a lesser extent galectin-8, markedly stimulate glioblastoma cell migration in vitro. Since bands for the transcripts of human galectins-2, -4 and -9 were apparently less frequent and intense in the 8 human glioblastoma cell lines, this system provides an excellent model to assign defined roles to individual galectins and delineate overlapping and distinct functional aspects.
...
PMID:Galectins are differentially expressed in supratentorial pilocytic astrocytomas, astrocytomas, anaplastic astrocytomas and glioblastomas, and significantly modulate tumor astrocyte migration. 1114 98
The glycoprotein 90K was originally described as a tumor-secreted antigen and subsequently found to have immunostimulatory activity as well as other possible functions. This protein interacts with an endogenous lectin,
galectin-3
, and may play a role in tumor metastasis through this interaction. Because 90K is heavily glycosylated, it may also interact with other members of the galectin family, which would contribute to the multifunctionality of 90K. To test this possibility, we studied the recognition of 90K by
galectin-1
, which, like
galectin-3
, has been associated with neoplastic transformation. In a solid-phase binding assay, human recombinant
galectin-1
bound immobilized human recombinant 90K in a fashion that was inhibitable by lactose. Galectins 1 and 3 appeared to bind to separate sites on 90K because they did not affect the binding of each other. The dissociation constant of
galectin-1
to 90K was on the order of 10(-7) M. Galectin-1 also induced aggregation of a human melanoma cell line, A375, in a carbohydrate-dependent manner, and this appeared to be mediated, at least in part, by 90K expressed on A375 cells, since it was inhibitable by a specific anti-90K monoclonal antibody. We conclude that 90K interacts with both
galectin-1
and
galectin-3
and both interactions contribute to the formation of multicell aggregates. Because both of these galectins as well as 90K are often over-expressed in neoplasm, these interactions may occur in the setting of various carcinomas and contribute to their progression and metastasis.
...
PMID:Glycoprotein 90K/MAC-2BP interacts with galectin-1 and mediates galectin-1-induced cell aggregation. 1114 40
Galectin-3
is a mammalian beta-galactoside-specific lectin with functions in cell growth, adhesion, and neoplastic transformation. On the basis of expression patterns in humans, it is proposed that
galectin-3
modulates fetal collecting duct growth. This article provides evidence that
galectin-3
can modulate branching morphogenesis of the mouse ureteric bud/collecting duct lineage. With the use of immunohistochemistry,
galectin-3
was not detected in early metanephrogenesis but was upregulated later in fetal kidney maturation when the protein was prominent in basal domains of medullary collecting ducts. Addition of
galectin-3
to embryonic days 11 and 12 whole metanephric cultures inhibited ureteric bud branching, whereas
galectin-1
did not perturb morphogenesis, nor did a
galectin-3
mutant lacking wild-type high-affinity binding to extended oligosaccharides. Exogenous
galectin-3
retarded conversion of renal mesenchyme to nephrons in whole metanephric explants but did not affect nephron induction by spinal cord in isolated renal mesenchymes. Finally, addition of a blocking antiserum to
galectin-3
caused dilation and distortion of developing epithelia in embryonic day 12 metanephroi cultured for 1 wk. The upregulation of
galectin-3
protein during kidney maturation, predominantly at sites where it could mediate cell/matrix interactions, seems to modulate growth of the ureteric tree.
...
PMID:Galectin-3 modulates ureteric bud branching in organ culture of the developing mouse kidney. 1118 99
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