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)

Galectin-3 (Gal-3), a pleiotropic carbohydrate-binding protein, is a selective binding partner of activated K-Ras-GTP. Because both proteins are antiapoptotic and associated with cancer progression, we questioned the possible functional role of Gal-3 in K-Ras activation. We found that overexpression of Gal-3 in human breast cancer cells (BT-549/Gal-3) coincided with a significant increase in wild-type (wt) K-Ras-GTP coupled with loss in wt N-Ras-GTP, whereas the nononcogenic Gal-3 mutant proteins [Gal-3(S6E) and Gal-3(G182A)] failed to induce the Ras isoform switch. Only wt Gal-3 protein coimmunoprecipitated and colocalized with oncogenic K-Ras, resulting in its activation with radical alterations in Ras signaling pathway, whereby the activation of AKT and Ral was suppressed and shifted to the activation of extracellular signal-regulated kinase (ERK). Specific inhibitors for Ras or mitogen-activated protein/ERK kinase (farnesylthiosalicylic acid and UO126, respectively) inhibited Gal-3-mediated apoptotic resistance and anchorage-independent growth functions. In conclusion, this study shows that Gal-3 confers on BT-549 human breast carcinoma cells several oncogenic functions by binding to and activation of wt K-Ras, suggesting that some of the molecular functions of Gal-3 are, at least in part, a result of K-Ras activation.
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PMID:Galectin-3 regulates a molecular switch from N-Ras to K-Ras usage in human breast carcinoma cells. 1610 80

The diagnosis of parathyroid carcinoma (PC) is difficult and based on morphological features that are not totally reliable. Several molecular markers proved useful in the evaluation of PC, but their sensitivity, specificity, or both are rather low. With the aim of identifying a marker of malignancy in parathyroid tumors, we tested the expression of galectin-3 (Gal-3), a lectin expressed in several malignant tumors, including follicular carcinomas (but not adenomas) of the thyroid. Twenty-six PCs and 30 control parathyroid adenomas (PAs) were collected. The PCs had been diagnosed based on capsular/vascular invasion (26/26 cases), extraparathyroid infiltration (16), local recurrence (9), and distant metastases (6). All cases were immunohistochemically tested for Gal-3 and for other markers claimed to be useful in the differential diagnosis of parathyroid neoplasms, namely, Ki67, p27, and bcl2. Gal-3 was expressed by 24 of the PC (92.3%), but only 1 PA (3.3%) (P < .001). All metastasizing PCs were Gal-3-positive. As expected, the Ki67 proliferative index was higher in PCs (mean, 6.7%) than in PAs (1.9%); p27 was down-regulated in 61.5% of PCs and only 33.3% of PAs, whereas bcl2 was strongly positive in most PAs and in 38.5% of PCs. In a suspected PC, the association of Gal-3 with Ki67 (using a cutoff of 6% for the proliferative activity) appeared the best marker combination (sensitivity 96.2%, specificity 90%), and the profile Gal-3-positive/Ki67 >6% was unique to PCs. We conclude that Gal-3 immunostaining is a valuable tool to support a diagnosis of PC in highly proliferating (Ki67 >6%) tumors affecting a single parathyroid gland.
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PMID:Galectin-3 expression in parathyroid carcinoma: immunohistochemical study of 26 cases. 1611 8

Galectin-3 (Gal-3), a beta galactoside-binding protein, has been implicated in a variety of biological functions including cell growth, differentiation, tumor cell adhesion, angiogenesis, tumor progression, and metastasis. We recently reported that Gal-3 was expressed in a subset of normal pituitary cells and tumors including PRL, ACTH, and in folliculo-stellate (FS) cells and tumors and that Gal-3 had an important regulatory role in pituitary cell proliferation. We further investigated the expression of Gal-3 protein in ACTH- and PRL-producing tumors and the expression of various galectin mRNAs by RT-PCR in pituitary adenomas and normal pituitary. Most silent ACTH subtypes 1 and 2 adenomas were negative or only focally positive for Gal-3 expression compared to functioning ACTH tumors from patients with Cushing's disease and Nelson's syndrome. In the normal pituitary, Gal-3 was expressed in less than 1% of the basophil-invading cells (ACTH cells present in the posterior pituitary) and in a subset of the anterior lobe ACTH-positive cells. RT-PCR analyses showed that many members of the galectin family including galectins 1, 2, 3, 4, 5, 6, 7, 8, and 9 were expressed in normal pituitary and in functioning ACTH- and PRL-producing tumors. These results indicate that Gal-3 is associated with functioning ACTH and PRL tumors and is expressed infrequently in silent ACTH adenomas, suggesting that Gal-3 protein and/or gene is altered in non-functioning ACTH tumors. The use of ACTH and Gal-3 immunostaining should help in the diagnosis of silent ACTH adenomas.
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PMID:Galectin-3 Expression in Functioning and Silent ACTH-Producing Adenomas. 1619 95

In this study, the expression patterns of Galectin-3 (Gal-3) and the frequency of infiltrating CD1a positive dendritic cells (DCs) were determined in 82 cases of vulvar tissues, consisting of normal squamous epithelia (NE, N = 10), vulvar condylomas (VC, N = 24), high grade vulvar intraepithelial neoplasias (HG-VIN, N = 26) of common type, and invasive keratinizing squamous cell carcinomas (SCC, N = 22) by a standard immunohistochemical method using monoclonal antibodies to investigate their differential expression in vulvar squamous dysplasia and infiltrating carcinomas with an emphasis on neoplastic transformation and progression. Gal-3 expression was cytoplasmic, nuclear or membranous in NE, VCs, and HG-VINs, with negative or weak and occasionally moderate reactivities. In SCCs, exclusively cytoplasmic staining patterns with moderate or strong reactivity in 59% of cases were observed (p < 0.0001, chi-square test); Gal-3 expression was not related with stage, grade, and recurrence. The frequency of CD1a positive DCs increased from NE and VCs to highest numbers in HG-VINs, was lowest in SCCs (p < 0.0001, ANOVA), and was not related with stage and grade, but with recurrence in SCCs (p = 0,048, t-test). This study indicates that qualitative and quantitative changes of Gal-3 immunoexpression and infiltration by CD1a positive DCs in vulvar NE, VCs, and HG-VIN lesions, respectively, compared with SCCs play a role in the development of an infiltrative phenotype, and may provide adjunctive criteria in the diagnosis of invasion of vulvar squamous epithelia.
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PMID:Galectin-3 and CD1a-positive dendritic cells are involved in the development of an invasive phenotype in vulvar squamous lesions. 1630 81

We previously demonstrated that treatment of acute asthmatic rats with gene therapy using plasmid-encoding Galectin-3 (Gal-3) resulted in an improvement of cellular and functional respiratory parameters. The next question that we wanted to clarify was if in a chronic situation where the treated animal continues to inhale the Ag, does this procedure prevent the chronicity and the remodeling? Chronic inflammation was induced by intranasal administration of OVA over a period of 12 wk. In the treated group, the Gal-3 gene was introduced by intranasal instillation in 50 mul of plasmid-encoding Gal-3. Noninvasive airway responsiveness to methacholine was tested at different times. Cells were obtained by bronchoalveolar lavage and used for RNA extraction and cytometric studies. Eosinophils were counted in blood and bronchoalveolar lavage fluid. Real-time PCR was used to measure Gal-3 and cytokine mRNA expression in lung. Lungs were paraffined and histologic analyses were performed (H&E, periodic acid-Schiff, and Masson Trichrome stain). Our results showed that 12 wk after the first intranasal Ag instillation in chronically asthmatic mice, treatment with the Gal-3 gene led to an improvement in the eosinophil count and the normalization of hyperresponsiveness to methacholine. Concomitantly, this treatment resulted in an improvement in mucus secretion and subepithelial fibrosis in the chronically asthmatic mice, with a quantitatively measured reduction in lung collagen, a prominent feature of airway remodeling. Plasmid-encoding Gal-3 acts as a novel treatment for chronic asthma in mice producing nearly complete blockade of Ag responses with respect to eosinophil airway accumulation, airway hyperresponsiveness, and remodeling.
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PMID:Inhibition of chronic airway inflammation and remodeling by galectin-3 gene therapy in a murine model. 1642 26

Annexin 1 (ANXA1), galectin-1 (Gal-1) and galectin-3 (Gal-3) proteins have been identified as important mediators that promote or inhibit leukocyte migration. The expression of these proteins was studied in human neutrophils and endothelial cells (ECs) during a transmigration process induced by IL-8. Upon neutrophil adhesion to EC, a significant increase in the cleaved ANXA1 (LCS3, raised against all ANXA1 isoforms) expression was detected in the plasma membrane of adhered neutrophils and ECs compared to intact ANXA1 isoform (LCPS1, against N-terminus of protein). Adherent neutrophils had elevated Gal-3 levels in the nucleus and cytoplasm, and ECs in their plasma membranes. In contrast, a decrease in the total amounts of Gal-1 was detected in migrated compared to non-migrated neutrophils. Therefore, ANXA1 and Gal-3 changed in their content and localization when neutrophils adhere to endothelia, suggesting a process of sensitive-balance between two endogenous anti- and pro-inflammatory mediators.
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PMID:Interaction of human neutrophils with endothelial cells regulates the expression of endogenous proteins annexin 1, galectin-1 and galectin-3. 1653 Apr 34

Prostate cancer is one of the malignant tumors which exhibit resistance to anticancer drugs, at least in part due to enhanced antiapoptotic mechanisms. Therefore, the understanding of such mechanisms should improve the design of chemotherapy against prostate cancer. Galectin-3 (Gal-3), a multifunctional oncogenic protein involved in the regulation of tumor proliferation, angiogenesis, and apoptosis has shown antiapoptotic effects in certain cell types. Here, we show that the expression of exogenous Gal-3 in human prostate cancer LNCaP cells, which do not express Gal-3 constitutively, inhibits anticancer drug-induced apoptosis by stabilizing the mitochondria. Thus, Gal-3-negative cells showed 66.31% apoptosis after treatment with 50 micromol/L cis-diammine-dichloroplatinum for 48 hours, whereas two clones of Gal-3-expressing cells show only 2.92% and 1.42% apoptotic cells. Similarly, Gal-3-negative cells showed 43.8% apoptosis after treatment with 300 micromol/L etoposide for 48 hours, whereas only 15.38% and 14.51% of Gal-3-expressing LNCaP cells were apoptotic. The expression of Gal-3 stimulated the phosphorylation of Ser(112) of Bcl-2-associated death (Bad) protein and down-regulated Bad expression after treatment with cis-diammine-dichloroplatinum. Gal-3 also inhibited mitochondrial depolarization and damage after translocation from the nuclei to the cytoplasm, resulting in inhibition of cytochrome c release and caspase-3 activation. These findings indicate that Gal-3 inhibits anticancer drug-induced apoptosis through regulation of Bad protein and suppression of the mitochondrial apoptosis pathway. Therefore, targeting Gal-3 could improve the efficacy of anticancer drug chemotherapy in prostate cancer.
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PMID:Galectin-3 regulates mitochondrial stability and antiapoptotic function in response to anticancer drug in prostate cancer. 1654 Jun 61

1. Ras signaling and oncogenesis depend on the dynamic interplay of Ras with distinctive plasma membrane (PM) microdomains and various intracellular compartments. Such interaction is dictated by individual elements in the carboxy-terminal domain of the Ras proteins, including a farnesyl isoprenoid group, sequences in the hypervariable region (hvr)-linker, and palmitoyl groups in H/N-Ras isoforms. 2. The farnesyl group acts as a specific recognition unit that interacts with prenyl-binding pockets in galectin-1 (Gal-1), galectin-3 (Gal-3), and cGMP phosphodiesterase delta. This interaction appears to contribute to the prolongation of Ras signals in the PM, the determination of Ras effector usage, and perhaps also the transport of cytoplasmic Ras. Gal-1 promotes H-Ras signaling to Raf at the expense of phosphoinositide 3-kinase (PI3-K) and Ral guanine nucleotide exchange factor (RalGEF), while galectin-3 promotes K-Ras signaling to both Raf and PI3-K. 3. The hvr-linker and the palmitates of H-Ras and N-Ras determine the micro- and macro-localizations of these proteins in the PM and in the Golgi, as well as in 'rasosomes', randomly moving nanoparticles that carry palmitoylated Ras proteins and their signal through the cytoplasm.4. The dynamic compartmentalization of Ras proteins contributes to the spatial organization of Ras signaling, promotes redistribution of Ras, and provides an additional level of selectivity to the signal output of this regulatory GTPase.
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PMID:Spatiotemporal organization of Ras signaling: rasosomes and the galectin switch. 1669 42

Monocytes are one of the key inflammatory cells recruited to xenografts and play an important role in delayed xenograft rejection. Previous studies have demonstrated the ability of monocytes to bind to the major xenoantigen Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R; however, the receptor that mediates this interaction has yet to be identified. We provide evidence that it is Galectin-3, a approximately 30-kDa lectin that recognizes beta-galactosides (Gal-beta(1-3/4)GlcNAc) and plays diverse roles in many physiological and pathological events. Human monocyte binding is strikingly increased on porcine aortic endothelial cells (PAEC), which express high levels of Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R, compared with human aortic endothelial cells. Human monocytes obtained from healthy donors bind to Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R at variable intensities. This variation of binding intensity was consistent and reproducible in individual donors. Galectin-3 is mainly expressed in human monocytes, not lymphocytes. Purified Galectin-3 is able to bind directly to Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R. Galectin-3 can also be affinity isolated from monocytes (and not lymphocytes) using an Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R-biotin/streptavidin-bead pull-down system. Soluble Galectin-3 binds preferentially to PAEC vs human aortic endothelial cells, and this binding can be inhibited by lactose, indicating dependence on the carbohydrate recognition domain of Galectin-3. Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R is at least partly responsible for this phenomenon, as binding decreased after digestion of PAEC with alpha-galactosidase. Furthermore, monocytes pretreated with a blocking anti-Galectin-3 Ab show decreased adhesion to PAEC when compared with isotype control in a parallel plate flow chamber perfusion assay. Thus, we conclude that Galectin-3 expressed in human monocytes is a receptor for the major xenoantigen (Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R), expressed on porcine endothelial cells.
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PMID:Human monocytes recognize porcine endothelium via the interaction of galectin 3 and alpha-GAL. 1681 89

This study presents the first QSAR model for Galectin-3 glycomimetic inhibitors based on docked structures to the carbohydrate recognition domain (CRD). Quantitative numerical methods such as PLS (Partial Least Squares) and ANN (Artificial Neural Networks) have been used and compared on QSAR models to establish correlations between molecular properties and binding affinity values (Kd). Training and validation of QSAR predictive models was performed on a master dataset consisting of 136 compounds. The molecular structures and binding affinities (Kd) (136 compounds) were obtained from the literature. To address the issue of dimensionality reduction, molecular descriptors were selected with PLS contingency approach, ANN, PCA (Principal Component Analysis) and GA (Genetic Algorithms) for the best predictive Galectin-3 binding affinity (Kd). Final sets comprising 56, 31 and 35 descriptors were obtained with PLS, PCA and ANN, respectively. The objective of this prototype QSAR model is to serve as a first guideline for the design of novel and potent Gal-3 selective inhibitors with emphasis on modification at both C-3' and at O-3 positions.
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PMID:A first QSAR model for galectin-3 glycomimetic inhibitors based on 3D docked structures. 1701 87


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