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)

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.
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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.
Int J Cancer 2001 Jan 15
PMID:Glycoprotein 90K/MAC-2BP interacts with galectin-1 and mediates galectin-1-induced cell aggregation. 1114 40

Galectin-3 is a member of the beta-galactoside-binding mammalian lectin family with affinity to ABH group epitopes, cell surface and extracellular polylactosamine glycans. It has been shown to be involved in differentiation, morphogenesis, tumor progression, and metastasis. Here we questioned the possible involvement of galectin-3 in the neoplastic progression of the tongue epithelium and evaluated its prognostic value in tongue cancer patients. Galectin-3 expression was analyzed by the immunohistochemical method in 77 tongue specimens (54 squamous cell carcinomas and 23 specimens of distinct normal mucosa). Levels of nuclear expression of galectin-3 markedly decreased during the progression from normal to cancerous states (P < 0.0001), while cytoplasmic expression increased (P < 0.0001). Enhanced expression of galectin-3 in the cytoplasm was associated with a reduced disease-free survival of tongue cancer patients. Multivariate analysis identified enhanced expression of cytoplasmic galectin-3 as an independent predictor of disease recurrence (P = 0.0120). These results suggest that the observed translocation of galectin-3 from the nucleus to the cytoplasm during neoplastic progression may serve as a prognostic factor for tongue cancer patients.
Clin Cancer Res 2000 Dec
PMID:Expression of cytoplasmic galectin-3 as a prognostic marker in tongue carcinoma. 1115 13

Galectins are galactoside-binding proteins that exhibit an important function in tumor progression by promoting cancer cell invasion and metastasis formation. Using Northern blotting and Western blotting analysis, in situ hybridization (ISH), and immunohistochemistry (IHC), we studied galectin-1 and galectin-3 in tissue samples of 33 primary pancreatic cancers and in tumor metastases in comparison to 28 normal pancreases. Furthermore, the molecular findings were correlated with the clinical and histopathological parameters of the patients. Northern blotting and Western blotting analysis showed significantly higher galectin-1 and galectin-3 mRNA and protein levels in pancreatic cancer samples than in normal controls. For galectin-1, no ISH signals and immunoreactivity were observed in acinar or ductal cells in the normal pancreas and in pancreatic cancer cells, whereas fibroblasts and extracellular matrix cells around the cancer mass exhibited strong mRNA signals and immunoreactivity. Galectin-3 mRNA signals and immunoreactivity were strongly present in most pancreatic cancer cells, whereas in the normal controls only faint ISH and IHC signals were seen in some ductal cells. Metastatic pancreatic cancer cells exhibited moderate to strong galectin-3 immunoreactivity but were negative for galectin-1. No relationship between the galectin-1 and galectin-3 mRNA levels and the tumor stage or between the IHC staining score and the tumor stage was found. However, galectin-1 mRNA levels and the IHC staining score were significantly higher in poorly differentiated tumors compared with well/moderately differentiated tumors, whereas for galectin 3 no differences were found. The expression pattern of galectin-1 and galectin-3 in pancreatic cancer tissues indicates that galectin-1 plays a role in the desmoplastic reaction that occurrs around pancreatic cancer cells, whereas galectin-3 appears to be involved in cancer cell proliferation. High levels of galectin-3 in metastatic cancer cells suggest an impact on metastasis formation.
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PMID:Comparative analysis of galectins in primary tumors and tumor metastasis in human pancreatic cancer. 1125 57

Galectin-3, a beta-galactoside binding protein, plays a significant role in cell to extracellular matrix interactions. Despite its extracellular expression, the precise physiological mechanisms that trigger its release from the intracellular milieu have not been characterized. The present analyses were, therefore, done to identify the extracellular matrix proteins with propensity to induce the release of intracellular galectin-3 from breast carcinoma cells. Our studies demonstrate that fetuin, a serum glycoprotein that is abundant in the fetal serum, is capable of inducing the rapid release (approximately 1 min) of intracellular galectin-3 from the cells. The mechanism by which galectin-3 is rapidly released appears to be novel and does not depend on changes in intracellular calcium levels. We also report that galectin-3-expressing breast carcinoma cells in serumless medium adhere and spread well on microtiter wells in the presence of fetuin and divalent ions in a carbohydrate-dependent manner. The data suggest that fetuin is a natural modulator of galectin-3 secretion/release and that the secreted galectin-3 modulates the activity of cell surface receptors for extracellular matrix proteins.
Cancer Res 2001 Mar 01
PMID:Rapid release of intracellular galectin-3 from breast carcinoma cells by fetuin. 1128 Jul 40

Galectin-3 is an endogenous beta-galactoside-binding protein with specificity for type I and II ABH blood group epitopes and poly-N-acetyllactosamine glycan-containing cell surface glycoproteins and is the major nonintegrin cellular laminin-binding protein. Galectin-3 is expressed at an elevated level in a wide range of neoplasms, and expression was shown to be associated in some tumor cell systems with metastases. Here we determined the functional consequence of blocking galectin-3 expression in highly malignant human breast carcinoma MDA-MB-435 cells. Inhibition of galectin-3 expression led to reversion of the transformed phenotype as determined by altered morphology, loss of serum-independent growth, acquisition of growth inhibition properties by cell contact, and abrogation of anchorage-independent growth. The blockage of galectin-3 expression led to a significant suppression of tumor growth in nude mice. These results provide direct evidence that galectin-3 expression is necessary for the maintenance of the transformed and tumorigenic phenotype of MDA-MB-435 breast carcinoma cells.
Clin Cancer Res 2001 Mar
PMID:Down-regulation of galectin-3 suppresses tumorigenicity of human breast carcinoma cells. 1129 62

Galectin-3 belongs to a group of endogenous lectins with an affinity to glycoconjugates containing beta-galactoside residues. It has been detected in numerous tissues and studied in connection with tumor growth, dedifferentiation, and metastasis. Only few studies have dealt with galectin-3 detection in tumors of the thyroid gland and with its possible role for differential diagnosis. We studied 118 cases of thyroid gland tumors with a monoclonal antibody against galectin-3; we compared the preparations by a semiquantitative score to determine differences in expression. Normal thyroid gland tissue, goiter tissue, and tissue with functional enhancement were largely negative for galectin-3. Adenomas with a typical cytological pattern were predominantly negative, but a focal positive reaction in single cells and cell groups or follicles was possible. Almost all papillary carcinomas showed a distinct galectin-3 expression. While findings in follicular carcinomas and oxyphilic adenomas and carcinomas were very uneven, with both positive and negative tumors, the galectin-3 reaction can be helpful in recognizing follicular variants of the papillary carcinoma. Investigation of the biological significance of tumors should always be cautious and consider known histological criteria for malignancy.
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PMID:[Expression of galectin-3 in thyroid gland and follicular cell tumors of the thyroid. A critical study of its possible role in preoperative differential diagnosis]. 1140 51

Interactions of metastatic cancer cells with vasculatory endothelium are critical during early stages of cancer metastasis. Understanding the molecular underpinnings of these interactions is essential for the development of new efficacious cancer therapies. Here we demonstrate that cancer-associated carbohydrate T antigen plays a leading role in docking breast and prostate cancer cells onto endothelium by specifically interacting with endothelium-expressed beta-galactoside-binding protein, galectin-3. Importantly, T antigen-bearing glycoproteins are also capable of mobilizing galectin-3 to the surface of endothelial cells, thus priming them for harboring metastatic cancer cells. The T antigen-mediated, tumor-endothelial cell interactions could be efficiently disrupted using synthetic compounds either mimicking or masking this carbohydrate structure. High efficiency of T antigen-mimicking and T antigen-masking inhibitors of tumor cell adhesion warrants their further development into antiadhesive cancer therapeutics.
Cancer Res 2001 Jun 15
PMID:The role of Thomsen-Friedenreich antigen in adhesion of human breast and prostate cancer cells to the endothelium. 1140 62

An 87-year-old man presented with hematuria and dysuria. An endoscopic examination revealed a bladder mucosa which was almost entirely occupied by diverticula. On the left lateral wall of the bladder there was a huge diverticulum which contained a 12 cm mass extending beyond the bladder wall in the extraperitoneal tissues. Upon histological examination the mass proved to be a carcinosarcoma which was composed by a squamous carcinoma and a sarcoma resembling a malignant fibrous histiocytoma. The two components, i.e. carcinomatous and sarcomatous, were separated by a sharp collision border and no intermingling was ever noted. The epithelial component showed immunoreactivity for cytokeratin and EMA, while the mesenchymal component was diffusely reactive for vimentin, alpha-1-antitrypsin and lysozime. Both components were reactive for galectin-3, whereas S100, desmin and smooth muscle actin were negative. This is the fourth reported case of carcinosarcoma originating in a bladder diverticulum.
J Exp Clin Cancer Res 2001 Jun
PMID:Rare presentation of carcinosarcoma arising in bladder diverticulum. 1148 92

Galectin-3 is a beta-galactoside-binding protein which regulates many biological processes including cell adhesion, migration, cell growth, tumor progression, metastasis, and apoptosis. Although the exact function of galectin-3 in cancer development is unclear, galectin-3 expression is associated with neoplastic progression and metastatic potential. Since studies have suggested that tumor cell survival in microcirculation determines the metastatic outcome, we examined the effect of galectin-3 overexpression in human breast carcinoma cell survival using the liver ischemia/reperfusion metastasis model. While the majority of control cells died by hepatic ischemia/reoxygenation, nearly all of galectin-3 overexpressing cells survived. We showed that galectin-3 inhibits nitrogen free radical-mediated apoptosis, one of the major death pathways induced during hepatic ischemia/reperfusion. Galectin-3 inhibition of apoptosis involved protection of mitochondrial integrity, inhibition of cytochrome c release and caspase activation. Taking these results together with the previous observation that galectin-3 inhibits apoptosis induced by loss of cell adhesion, we propose that galectin-3 is a critical determinant for anchorage-independent and free radical-resistant cell survival during metastasis.
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PMID:Galectin-3 protects human breast carcinoma cells against nitric oxide-induced apoptosis: implication of galectin-3 function during metastasis. 1154 97


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