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

Soluble endogenous lactoside-binding lectins, galectins, have been implicated in cell adhesion, growth, differentiation, neoplastic transformation, and metastasis. Two major classes of these lectins, galectin-1 and galectin-3, are developmentally regulated. To explore the mechanisms by which the expression of the galectins is regulated and to examine their association with the differentiation processes induced by all-trans retinoic acid (RA), dibutyryl cyclic AMP (Bt2cAMP) and their combination, we used the murine embryonal carcinoma (EC) cell line F9 and its RA-resistant mutant, RA-3-10. RA induced endodermal differentiation and a concurrent induction of galectin-1 and its complementary glycoconjugates (laminin and lysosomal-associated membrane protein, LAMP) in the F9 wild-type (wt) line, but failed to induce differentiation and had no effects on or even reduced the expression of galectin-1, laminin, and LAMP in the RA-3-10 line. On the other hand, RA inhibited expression of galectin-3 in the wild-type line but had no effect on the RA-3-10 line. The galectin-1 gene is at least partially regulated at the transcriptional level. These results demonstrate a parallel association between differentiation and induction of galectin-1, and inhibition of galectin-3 in F9 cells by RA. The study suggests that a regulated expression of galectins and their complementary glycoconjugates is involved in the differentiation pathway induced by RA in F9 cells.
 ...
PMID:A parallel association between differentiation and induction of galectin-1, and inhibition of galectin-3 by retinoic acid in mouse embryonal carcinoma F9 cells. 986 5

We have analyzed the expression of galectin-1 and galectin-3 in four human prostate carcinoma cell lines. Northern analysis and immunoblotting experiments showed that three cell lines express both galectins. However, only galectin-1 was detected on the surface of these cells. The LNCaP line expressed neither galectin. LNCaP was transfected with galectin-1 and four clones were isolated, all of which expressed galectin-1 on the cell surface. Kinetics of binding to extracellular matrix proteins appeared to be accelerated in the transfected lines, but overall binding was not enhanced. When the same experiments were performed in the presence of EDTA to eliminate the effects of integrins, binding of a galectin-1 clone to laminin and fibronectin was increased relative to the control cell line. We propose that galectins may contribute to the adhesive properties of some prostate cancer cells.
 ...
PMID:Differential expression of endogenous galectin-1 and galectin-3 in human prostate cancer cell lines and effects of overexpressing galectin-1 on cell phenotype. 991 95

Galectin-1 and galectin-3 are galactoside-binding proteins involved in different steps of tumor progression and potential targets for therapy. We have investigated the expression of these galectins in 38 human bladder transitional-cell carcinomas of different histological grade and clinical stage and in 5 normal urothelium samples. Galectin-1 mRNA levels were highly increased in most high-grade tumors compared with normal bladder or low-grade tumors. Western blot and immuno-histochemical analysis of normal and neoplastic tissues revealed a higher content of galectin-1 in tumors. Galectin-3 mRNA levels were also increased in most tumors compared with normal urothelium, but levels were comparable among tumors of different histological grade.
 ...
PMID:galectin-1 and galectin-3 expression in human bladder transitional-cell carcinomas. 998 30

Cell-matrix interactions are governed by a distinct set of proteins, with 2 nonintegrin laminin-binding proteins, galectin-1 and galectin-3, providing 1 aspect. The expression patterns of laminin and the 2 galectins and galectin binding sites were quantitatively determined by means of computer-assisted microscopy with the aim of differentiating between 16 leiomyomas and 10 leiomyosarcomas of the uterus. Three quantitative variables were computed for each of the 5 histochemical markers: labeling index, which describes the percentage of tissue area specifically stained by a given marker; mean optical density which reflects the concentration of the marker; and concentrational heterogeneity, which characterizes the degree of heterogeneity of the marker distribution in the tumor tissue areas. The results reveal evident differences in the galectin-3-related parameters in the 2 tumors groups. Whereas the concentration of galectin-3 binding sites was significantly (P = .01) weaker in the leiomyosarcomas than in the leiomyomas, the percentages of tumor tissue expressing galectin-3 (P = .02) and its binding sites (P = .002) were significantly higher in the leiomyosarcomas than in the leiomyomas. Although significantly (P = .02) higher, the concentration of laminin was more heterogeneously distributed (P = .01) in the leiomyosarcomas than in the leiomyomas. In contrast, the levels of expression of galectin-1 and its accessible binding sites remained similar for both the leiomyomas and the leiomyosarcomas. Finally we document how the levels of expression of galectin-3 and its binding sites can be of assistance in reliably differentiating leiomyomas from leiomyosarcomas.
 ...
PMID:Galectin fingerprinting in tumor diagnosis. Differential expression of galectin-3 and galectin-3 binding sites, but not galectin-1, in benign vs malignant uterine smooth muscle tumors. 1023 Mar 52

Galectins are vertebrate lectins interacting with beta-galactosides and derivates thereof such as blood group A, B and H determinants. The expression of gelectin-1 and -3 and galectin-specific binding sites by human Sertoli cells was analyzed in normal human testis and Sertoli cell only-syndrome (SCOS). Staining intensity was scored semiquantitatively on a 4-grade scale. Sertoli cells in normal testes displayed a moderate cytoplasmic and weak nuclear staining for galectin-1-specific binding sites. Galectin-3-specific binding sites were expressed in Sertoli cells less intensely than accessible ligands for galectin-1 (mean score 2.25 for galectin-1 and 1.50 for galectin-3). Germ cells were only weakly reactive. Tubular walls were negative for both classes of galectin-specific binding sites. In SCOS, galectin-1 binding was moderate to strong and more pronounced than galectin-3 binding by Sertoli cells (mean scores 4.00 and 2.25). Tubular walls were negative for galectin-staining. The ratio for galectin-1-/galectin-3-specific binding (staining score ratio) was 1.50 form normal testis and 1.78 for SCOS disclosing a relative increase of galectin-3 binding sites in the latter. Staining with galectin-1- and -3-specific antisera showed a strong cytoplasmic galectin-1 immunoreactivity in Sertoli cells of normal and SCOS testis (score 4.00 for both). Anti-galectin-3 did not stain Sertoli cells or germ cells in normal testis. Only Leydig cells were labeled (score 3.00). In SCOS a weak to moderate nuclear staining of Sertoli cells was noted (score 2.00). Galectin-3 expression and galectin-1-specific binding sites were found to be increased in Sertoli cells of SCOS. This modulation of reactivity can have implications for Sertoli cell interactions with galectin-reactive extracellular matrix components like laminin and for anti-apoptotic effects.
 ...
PMID:Sertoli cell expression of galectin-1 and -3 and accessible binding sites in normal human testis and Sertoli cell only-syndrome. 1042 46

We studied 2 families of molecules whose role remains uncharacterized or obscure in the progress of renal cell carcinoma (RCC): galectins, a major class of glycoproteins, and the Thomsen-Friedenreich (T) antigen. We characterized the level of expression of galectin-1 and galectin-3 and their respective binding sites in a series of 74 RCCs. We also characterized the level of expression of laminin, a natural ligand for galectins. Finally, we characterized the level of T antigen expression and the T antigen binding sites. All levels of expression were quantitatively determined by using computer-assisted microscopy on immunohistochemically or glycohistochemically stained slides. A small concentration of galectin-1 binding sites or a large concentration heterogeneity of galectin-3 can be associated with unfavorable prognoses for patients with grade II or III RCCs. In contrast, T antigen and T antigen binding sites revealed no change across the 2 RCC groups that exhibited different clinical outcomes. We established discriminant scores that permitted a clear distinction between the 2 RCC groups analyzed. Modifications to the expression of galectin-1 and galectin-3, but not of T antigen, parallel an increase in RCC aggressiveness. Galectins represent a family of molecules with a meaningful role in RCC progression.
 ...
PMID:Galectin-1 and galectin-3 binding pattern expression in renal cell carcinomas. 1043 99

Protein (lectin)-carbohydrate (cellular glycoconjugate) recognition is operative in biochemical information transfer. Galectins constitute a family of endogenous galactoside-binding lectins with conserved features in the binding site. The members of this lectin category are assumed to be involved in cell adhesion and growth regulation. To assess to what extent the different modes of binding-site presentation and/or carbohydrate fine-specificities will affect aspects of galectin behavior, homodimeric cross-linking galectin-1 and monomeric chimeric galectin-3, with its collagenase-sensitive stalk linked to the carbohydrate-recognition domain, were investigated. Cell-surface expression of the two galectins and accessible galectin-binding sites on various tumor cell lines was ascertained by FACScan analysis. In particular, ligand accessibility for the two galectins differed for the tested cell line types. Binding of tumor cells to laminin and plasma or placental fibronectin was generally reduced by treatment of cells or matrix with galectins. Galectin-3 was more efficient than galectin 1 at impairing laminin's potency as matrix. Cell binding of galectin-1, on the other hand, proved on average more effective for blocking cell association to fibronectins after its preincubation with cell suspensions. Differences were also apparent in the biodistribution of the galectins, where an avian homolog of galectin- served as the control to distinguish effects of spatial and sugar-binding features. Histopathological analysis of lymph-node-negative and -positive breast and colorectal carcinomas (n = 180 including 60 metastatic lesions) indicated a correlation of either increased galectin-1 binding and reduced galectin-3 expression or reduced binding of both galectins with the occurrence of lymph node lesions. Together with data on the heparin-binding lectin, revealing reduced expression to be associated with a positive lymph-node status in the breast cancer group, these results can be interpreted to reflect cell-type-dependent requirements of galectin ligand presentation during the metastatic cascade. By introducing mammalian lectins to lectin-histochemical studies, the detection of quantitative differences in glycosylation brings an understanding of its cell biological significance one step closer.
 ...
PMID:Galectins-1 and -3 and their ligands in tumor biology. Non-uniform properties in cell-surface presentation and modulation of adhesion to matrix glycoproteins for various tumor cell lines, in biodistribution of free and liposome-bound galectins and in their expression by breast and colorectal carcinomas with/without metastatic propensity. 1048 Mar 38

Starburst glycodendrimers offer the potential to serve as high-affinity ligands for clinically relevant sugar receptors. In order to define areas of application, their binding behavior towards sugar receptors with differential binding-site orientation but identical monosaccharide specificity must be evaluated. Using poly(amidoamine) starburst dendrimers of five generations, which contain the p-isothiocyanato derivative of p-aminophenyl-beta-D-lactoside as ligand group, four different types of galactoside-binding proteins were chosen for this purpose, i.e., the (AB)(2)-toxic agglutinin from mistletoe, a human immunoglobulin G fraction, the homodimeric galectin-1 with its two binding sites at opposite ends of the jelly-roll-motif-harboring protein and monomeric galectin-3. Direct solid-phase assays with surface-immobilized glycodendrimers resulted in obvious affinity enhancements by progressive core branching for the plant agglutinin and less pronounced for the antibody and galectin-1. High density of binding of galectin-3 with modest affinity increases only from the level of the 32-mer onwards points to favorable protein-protein interactions of the monomeric lectin and a spherical display of the end groups without a major share of backfolding. When the inhibitory potency of these probes was evaluated as competitor of receptor binding to an immobilized neoglycoprotein or to asialofetuin, a marked selectivity was detected. The 32- and 64-mers were second to none as inhibitors for the plant agglutinin against both ligand-exposing matrices and for galectin-1 on the matrix with a heterogeneous array of interglycoside distances even on the per-sugar basis. In contrast, a neoglycoprotein with the same end group was superior in the case of the antibody and, less pronounced, monomeric galectin-3. Intimate details of topological binding-site presentation and the ligand display on different generations of core assembly are major operative factors which determine the potential of dendrimers for applications as lectin-targeting device, as attested by these observations.
 ...
PMID:Lactose-containing starburst dendrimers: influence of dendrimer generation and binding-site orientation of receptors (plant/animal lectins and immunoglobulins) on binding properties. 1053 41

Although protein-carbohydrate interactions are supposed to play key roles in cell adhesion, signalling and growth control. Their exact role in skin physiology has only recently been investigated. The endogenous lectins galectin-1 and galectin-3 have been identified in skin including hair follicles. Here, we analyzed the expression and distribution of these galectins and their binding sites in C57BL/6 mice during hair cycle. The expression of galectin-1 and galectin-3 binding sites was found to be predominantly hair cycle-dependent showing some overlapping to the expression of galectin-1 and -3. The outer root sheath (ORS) expressed galectin-1 binding sites during anagen IV to VI and in early catagen, whereas galectin-1 was expressed from early anagen to late catagen. The ORS expressed galectin-3 binding sites during catagen transition corresponding to a galectin-3 expression during anagen V and catagen. The innermost layer of the ORS expressed galectin-3 binding sites during anagen VI until catagen VIII, but galectin-3 during anagen III to IV and catagen. The inner root sheath (IRS) expressed galectin-3 binding sites only in anagen IV but missed expression of any of the two galectins. The matrix cells expressed galectin-3 binding sites in catagen II-III as well as galectin-3 during anagen V to catagen IV. The present study provides the first evidence for a cycle-related expression of both galectin-1 and -3 and their binding sites during murine hair cycle.
 ...
PMID:Expression of galectin-1 and -3 and of accessible binding sites during murine hair cycle. 1066 99

Expression of glycan determinants for in situ binding is the prerequisite for a productive protein (lectin)-carbohydrate recognition. Labeled tissue lectins as tools are preferable to plant lectins to assess this parameter, because plant and animal lectins with identical saccharide specification can well differ in their profiles of oligosaccharide binding pattern. Due to their relevance in growth control and matrix adhesion the family of galectins (galactoside-binding metal ion independent animal lectins) is receiving increasing utilization in human biology. Employing biotinylated galectin-1 and galectin-3 we studied the expression of binding sites for these galectins in normal human squamous epithelium and human carcinomas from the oropharyngeal region and larynx in relation to the expression of LP-34+ cytokeratins by the procedure of double labeling. Tissue sites accessible for galectin-1 were located in all layers of normal epithelium and in tumor cells. In contrast, galectin-3 binding was suprabasal in the normal epithelium and in tumor cells exhibiting signs of keratinization. These results reveal differences in the localization of accessible sites for the two galectins. Relating to cell development galectin-3 appeared to display affinity to areas with increased extent of differentiation.
 ...
PMID:Endogenous lectins (galectins-1 and -3) as probes to detect differentiation-dependent alterations in human squamous cell carcinomas of the oropharynx and larynx. 1071 52


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>