Increased Expression Of Galectin-3 Research Articles

Galectin-1 in Obesity and Type 2 Diabetes.

Galectin-1 is a carbohydrate-binding protein expressed in many tissues. In recent years, increasing evidence has emerged for the role of galectin-1 in obesity, insulin resistance and type 2 diabetes. Galectin-1 has been highly conserved through evolution and is involved in key cellular functions such as tissue maturation and homeostasis. It has been shown that galectin-1 increases in obesity, both in the circulation and in the adipose tissue of human and animal models. Several proteomic studies have independently identified an increased galectin-1 expression in the adipose tissue in obesity and in insulin resistance. Large population-based cohorts have demonstrated associations for circulating galectin-1 and markers of insulin resistance and incident type 2 diabetes. Furthermore, galectin-1 is associated with key metabolic pathways including glucose and lipid metabolism, as well as insulin signalling and inflammation. Intervention studies in animal models alter animal weight and metabolic profile. Several studies have also linked galectin-1 to the progression of complications in diabetes, including kidney disease and retinopathy. Here, we review the current knowledge on the clinical potential of galectin-1 in obesity and type 2 diabetes.

Pooling analysis reveals that galectin-1 is a reliable prognostic biomarker in various cancers.

Galectin-1 is reported to be upregulated in various human cancers. However, the relationship between galectin-1 expression and cancer prognosis has not been systematically assessed. In this study, we searched PubMed, Web of Science, and Embase to collect all relevant studies and a meta-analysis was performed. We found that increased galectin-1 expression was associated with tumor size (odds ratio [OR] = 1.75; 95% confidence interval [CI]: 1.06-2.89; p = 0.029), clinical stage (OR = 3.89; 95% CI: 2.40-6.31; p < 0.001), and poorer differentiation (OR = 1.39; 95% CI: 1.14-1.69; p = 0.001), but not with age (OR = 1.07; 95% CI: 0.82-1.39; p = 0.597), sex (OR = 0.89; 95% CI: 0.74-1.07; p = 0.202), or lymph node metastasis (OR = 2.57; 95% CI: 0.98-6.78; p = 0.056). In addition, we found that high galectin-1 expression levels were associated with poor overall survival (HR = 2.12; 95% CI: 1.71-2.64; p < 0.001). The results were further validated using The Cancer Genome Atlas data set. Moreover, high galectin-1 expression was significantly associated with disease-free survival (hazard ratio [HR] = 1.60; 95% CI: 1.17-2.19; p = 0.003), progression-free survival (HR = 1.93; 95% CI: 1.65-2.25; p < 0.001), and cancer-specific survival (HR = 1.82; 95% CI: 1.30-2.55; p < 0.001). Our meta-analysis demonstrated that galectin-1 might be a useful common biomarker for predicting prognosis in patients with cancer.

Increased Galectin-1 Expression in Thymic Epithelial Tumors

IntroductionThymic epithelial tumors (TET) are rare malignancies with a paucity of data on biology and therapeutics. Galectin-1 is a member of the β-galactoside binding protein family and has been shown to mediate tumor growth via modulation of immune cell function. This study examined galectin-1 expression in TET. Patients and MethodsA tissue microarray of 68 patients with TET and 8 benign thymus controls were stained for galectin-1 expression and scored by a pathologist blinded to patient clinical and pathologic data. Galectin-1 expression +1 or greater staining intensity was considered positive. Clinical and pathologic data were abstracted from institutional databases. Expression of galectin-1 in thymic tumor was compared to benign thymus controls and correlated with pertinent clinical and pathologic data. ResultsGalectin-1 expression was higher in TET compared to benign thymus controls (65% vs. 0%). No significant association between galectin-1 expression and the development of recurrent disease, paraneoplastic syndromes, or overall survival was noted. ConclusionGalectin-1 is overexpressed in the majority of TET. Detection of galectin-1 may differentiate benign from neoplastic thymic processes. Additional studies are needed to assess the role of galectin-1 in the development of TET.

Both serum and tissue Galectin-1 levels are associated with adverse clinical features in neuroblastoma.

Neuroblastoma is one of the most common pediatric solid tumors. Although the 5-year overall survival rate has increased over the past few decades, high-risk patients still have a poor prognosis due to a lack of biomonitoring therapy. This study was performed to investigate the role of Galectin-1 in neuroblastoma biomonitoring therapy. A tissue microarray containing 37 neuroblastoma tissue samples was used to evaluate the correlation between Galectin-1 expression and clinical features. Blood samples were examined to better understand whether serum Galectin-1 (sGalectin-1) could be used for biomonitoring therapy. Kaplan-Meier analysis and ROC analysis was conducted to distinguish the outcome associated with high or low expression of Galectin-1 in patients with neuroblastoma. Increased Galectin-1 expression was found in neuroblastoma and it was further demonstrated that elevated tissue Galectin-1 expression was related to INSS stage, histology, bone marrow metastasis, and poor survival. sGalectin-1 levels were higher in newly diagnosed patients with neuroblastoma than healthy subjects. Patients with elevated sGalectin-1 through treatment cycles correlated with the poor chemo-responses and tended to have worse outcomes, such as metastasis or stable tumor size, whereas gradually decreasing sGalectin-1 levels correlated with no observed progression in clinical symptoms. Tissue and serum Galectin-1 levels were associated with adverse clinical features in patients with neuroblastoma, and sGalectin-1 could be a potential biomarker for monitoring therapy.

Galectin-1 expression imprints a neurovascular phenotype in proliferative retinopathies and delineates responses to anti-VEGF.

Neovascular retinopathies are leading causes of irreversible blindness. Although vascular endothelial growth factor (VEGF) inhibitors have been established as the mainstay of current treatment, clinical management of these diseases is still limited. As retinal impairment involves abnormal neovascularization and neuronal degeneration, we evaluated here the involvement of galectin-1 in vascular and non-vascular alterations associated with retinopathies, using the oxygen-induced retinopathy (OIR) model. Postnatal day 17 OIR mouse retinas showed the highest neovascular profile and exhibited neuro-glial injury as well as retinal functional loss, which persisted until P26 OIR. Concomitant to VEGF up-regulation, galectin-1 was highly expressed in P17 OIR retinas and it was mainly localized in neovascular tufts. In addition, OIR induced remodelling of cell surface glycophenotype leading to exposure of galectin-1-specific glycan epitopes. Whereas VEGF returned to baseline levels at P26, increased galectin-1 expression persisted until this time period. Remarkably, although anti-VEGF treatment in P17 OIR improved retinal vascularization, neither galectin-1 expression nor non-vascular and functional alterations were attenuated. However, this functional defect was partially prevented in galectin-1-deficient (Lgals1−/−) OIR mice, suggesting the importance of targeting both VEGF and galectin-1 as non-redundant independent pathways. Supporting the clinical relevance of these findings, we found increased levels of galectin-1 in aqueous humor from patients with proliferative diabetic retinopathy and neovascular glaucoma. Thus, using an OIR model and human samples, we identified a role for galectin-1 accompanying vascular and non-vascular retinal alterations in neovascular retinopathies.

Galectin-1 suppresses methamphetamine induced neuroinflammation in human brain microvascular endothelial cells: Neuroprotective role in maintaining blood brain barrier integrity

Methamphetamine (Meth) abuse can lead to the breakdown of the blood–brain barrier (BBB) integrity leading to compromised CNS function. The role of Galectins in the angiogenesis process in tumor-associated endothelial cells (EC) is well established; however no data are available on the expression of Galectins in normal human brain microvascular endothelial cells and their potential role in maintaining BBB integrity. We evaluated the basal gene/protein expression levels of Galectin-1, -3 and -9 in normal primary human brain microvascular endothelial cells (BMVEC) that constitute the BBB and examined whether Meth altered Galectin expression in these cells, and if Galectin-1 treatment impacted the integrity of an in-vitro BBB. Our results showed that BMVEC expressed significantly higher levels of Galectin-1 as compared to Galectin-3 and -9. Meth treatment increased Galectin-1 expression in BMVEC. Meth induced decrease in TJ proteins ZO-1, Claudin-3 and adhesion molecule ICAM-1 was reversed by Galectin-1. Our data suggests that Galectin-1 is involved in BBB remodeling and can increase levels of TJ proteins ZO-1 and Claudin-3 and adhesion molecule ICAM-1 which helps maintain BBB tightness thus playing a neuroprotective role. Galectin-1 is thus an important regulator of immune balance from neurodegeneration to neuroprotection, which makes it an important therapeutic agent/target in the treatment of drug addiction and other neurological conditions.

Integrated Stable Isotope Labeling by Amino Acids in Cell Culture (SILAC) and Isobaric Tags for Relative and Absolute Quantitation (iTRAQ) Quantitative Proteomic Analysis Identifies Galectin-1 as a Potential Biomarker for Predicting Sorafenib Resistance in Liver Cancer*

Sorafenib has become the standard therapy for patients with advanced hepatocellular carcinoma (HCC). Unfortunately, most patients eventually develop acquired resistance. Therefore, it is important to identify potential biomarkers that could predict the efficacy of sorafenib. To identify target proteins associated with the development of sorafenib resistance, we applied stable isotope labelling with amino acids in cell culture (SILAC)-based quantitative proteomic approach to analyze differences in protein expression levels between parental HuH-7 and sorafenib-acquired resistance HuH-7 (HuH-7(R)) cells in vitro, combined with an isobaric tags for relative and absolute quantitation (iTRAQ) quantitative analysis of HuH-7 and HuH-7(R) tumors in vivo. In total, 2,450 quantified proteins were identified in common in SILAC and iTRAQ experiments, with 81 showing increased expression (>2.0-fold) with sorafenib resistance and 75 showing decreased expression (<0.5-fold). In silico analyses of these differentially expressed proteins predicted that 10 proteins were related to cancer with involvements in cell adhesion, migration, and invasion. Knockdown of one of these candidate proteins, galectin-1, decreased cell proliferation and metastasis in HuH-7(R) cells and restored sensitivity to sorafenib. We verified galectin-1 as a predictive marker of sorafenib resistance and a downstream target of the AKT/mTOR/HIF-1α signaling pathway. In addition, increased galectin-1 expression in HCC patients' serum was associated with poor tumor control and low response rate. We also found that a high serum galectin-1 level was an independent factor associated with poor progression-free survival and overall survival. In conclusion, these results suggest that galectin-1 is a possible biomarker for predicting the response of HCC patients to treatment with sorafenib. As such, it may assist in the stratification of HCC and help direct personalized therapy.

Hypoxia induces Galectin-3 and Bcl-2 over-expression in human umbilical vein endothelial cells (HUVECs)

Angiogenesis, the growth of new blood vessels from pre-existing endothelium, is a critical phenomenon occurring during development and tissue regeneration. In pathological conditions such as inflammation and malignancies, hypoxia represent one of the most important driver of angiogenesis, mainly via the release of nitric oxide [1]. Here we investigate the behavior of human umbilical vein endothelial cells (HUVECs) treated with 100 mM CoCl2 for 24 hours, a condition mimicking hypoxia by the stabilization of HIF-1α and HIF-2α [2,3]. MTT and wound healing assays were performed to evaluate cell migration and proliferation, respectively, while Bcl-2 and Galectin-3 expression levels were analyzed by western blotting. We showed that hypoxic condition resulted in reduced proliferation and migration with increased expression of Galectin-3 and Bcl-2. These preliminary results provide new insights in the characterization of Galectin-3/Bcl-2 interplay in endothelial cell survival under hypoxic condition, and will contribute to a better understanding of hypoxia influences on tumor angiogenesis.

Altered galectin-1 serum levels in patients diagnosed with high-grade glioma

High-grade gliomas (HGG) are the most common and most aggressive intrinsic human brain tumors in adults. Galectin-1, a glycan-binding protein that is overexpressed in HGG, has been shown to contribute significantly to the aggressive nature of HGG. It is unknown whether increased galectin-1 expression levels are exclusively found at the tumor site or whether galectin-1 can also be detected in the serum of HGG patients. Galectin-1 serum levels were analyzed in a prospective dataset of 43 healthy controls and 125 patients with newly diagnosed or recurrent HGG. Samples were taken at the moment of surgical resection and/or 2-3weeks after surgery. Galectin-1 serum levels were determined using an ELISA for galectin-1. Galectin-1 serum levels depended significantly on age and sex in the control group. Age- and sex-adjusted galectin-1 serum levels were significantly higher in all patient subgroups compared to healthy controls with a high discriminative ability that increased with age. We did not observe a significant decrease in the galectin-1 serum levels upon surgical resection of the tumor. Collectively, the data presented here may represent a first step to establish galectin-1 as a biomarker in HGG disease monitoring. Further longitudinal evaluation is required and ongoing to investigate the value of galectin-1 serum levels in HGG patients as an additional diagnostic marker, but more importantly as a predictor of treatment response and prognosis. Furthermore, galectin-1 serum levels could also provide an important tool for the identification of HGG patients that could benefit from galectin-1 directed therapies that are currently under development.

Abstract 4644: A novel strategy for targeted drug delivery to the tumor vasculature by radiation-induced receptor expression on endothelial cells

Abstract One of the primary goals of a successful cancer treatment regimen is to deliver an effective combination of radiation and/or drugs to tumors while minimizing damage to normal tissues. Many anti-angiogenic agents, while not able to control tumor growth, possess the ability to selectively target the location and process of tumor blood vessel formation. Conversely many chemotherapy agents are highly cytotoxic and lack selective targeting ability thus decreasing the therapeutic ratio. We are investigating a new drug delivery strategy exploiting the tumor endothelium “stimulated” by ionizing radiation to preferentially target and deliver a nanoparticulate formulation of arsenic trioxide (ATO) encapsulated in liposomal vesicles or “nanobins” to the irradiated tumor tissue. The targeting is via the 33 amino acid anti-angiogenic peptide, anginex. The identification of galectin-1 as the receptor for anginex expressed on activated endothelial cells involved in tumor angiogenesis has revealed a solid basis for this therapeutic rationale. Unlike the antiangiogenic agent Avastin, which is an antibody that targets the vascular endothelial growth factor (VEGF) released by the tumor cells into the microenvironment, this peptide binds to galectin-1, a tumor endothelial cell specific antigen that is expressed in solid tumors. We have made the novel discovery that galectin-1 expression is further upregulated in the tumor after radiation exposure, particularly on the endothelial cell surface. Exposure of murine SCK breast tumors to a clinical radiation dose of 2Gy induced a substantial average increase of 141 +/− 49% in anginex uptake as assessed by [18]-F-labeled anginex biodistribution. These results suggest that anginex may be an effective targeting molecule for image and radiation-guided therapy of solid tumors. To assist in delineating the exact mechanisms for our radiation-guided drug delivery strategy, we have developed a system to grow 3D tumor cell-endothelial cell spheroids and have observed increased galectin-1 expression upon radiation exposure. We are using these spheroidal cultures to implant tumors in dorsal skin fold window chambers for intravital wavelength imaging of drug delivery to tumor tissue before and after radiation exposure. Understanding how anginex uptake selectively increases in endothelial cells after irradiation and its nexus to radiation-sensitivity and drug delivery is our current focus. Further studies are underway to characterize the in vivo targeting of arsenic trioxide chemotherapy via anginex-conjugated ‘nanobins’ in combination with radiation exposure and assess the therapeutic potential in our solid tumor model. Supported by NCI grant CA107160 and the Central Arkansas Radiation Therapy Institute. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4644. doi:1538-7445.AM2012-4644

Increased galectin-1 expression in muscle of Astragalus polysaccharide-treated Type 1 diabetic mice

In order to investigate the immunopharmacological function of Astragalus polysaccharide (APS) in Type 1 diabetes mellitus (T1DM), multiple low-dose streptozotocin-induced diabetic mice and normal mice were administered either APS or saline intraperitoneally once daily. The changes in galectin-1 expression in different organs of the mice were detected by ELISA, Real-time fluorescence quantitative RT-PCR and Western blot. The percentages of apoptotic CD8(+) T cells from spleens of APS-treated diabetic mice were measured by flow cytometry. We found that the expression of galectin-1 was increased in serum of APS-treated diabetic mice compared to the non-treated diabetic mice (*p<0.05). Increased galectin-1 was mainly expressed in the muscle of APS-treated mice. In vitro, APS up-regulated the expression of galectin-1 in muscle cells in a dose-dependent manner. The percentage of apoptotic CD8(+) T cells in spleens of APS-treated mice was positively correlated with the concentration of APS treatment, and the blocking of galectin-1 in vivo by specific antibody reduced the percentage of apoptotic CD8(+) T cells in APS-treated mice. Our findings indicated that APS could up-regulate the expression of galectin-1 in muscle of T1DM mice, resulting in the apoptosis of CD8(+) T cells. This may be an important mechanism by which APS protects β cells of the pancreatic islets from apoptosis induced by CD8(+) T cells in T1DM in vivo.

The Potential Role of Galectin-1 in Hypoxia Induced AML Cell Differentiation through C/EBPαa Transcription Regulation.

Abstract 3120Poster Board III-57Recently we reported that cobalt chloride-simulated hypoxia and mild hypoxia could induce the differentiation of human acute myeloid leukemic (AML) cells probably through hypoxia inducible factor-1 alpha (HIF-1αa) independent of its transcription activity. In this study, we used differential gel electrophoresis to compare the HIF-1αa regulated proteins between conditional induction and absence of HIF-1αa protein in U937T cells. Among all the up-regulated proteins indentified, the mRNA and protein level of galectin-1 was most remarkably changed. Knockdown of galectin-1 partially blocked the differentiation induced by HIF-1αa overexpression in U937T cells as assessed by morphological criteria and differentiation associated-antigens. Notably, reduced expression of C/EBPαa, a critical transcription factor for granulocyte differentiation, could inhibit the up-regulation of galectin-1 induced by HIF-1αa, and inducible expression of C/EBPαa in U937T cells also increased galectin-1 expression. Furthermore, by using the luciferase assay and chromatin immunoprecipitation we localized the binding site of C/EBPαa in the promoter of galectin-1. Finally the role of galectin-1 during chloride-simulated hypoxia and mild hypoxia was addressed by decreasing the expression of galectin-1 with small interfering RNA. Taken together, these results conclude that galectin-1 is required for hypoxia triggered C/EBPαa dependent AML cell differentiation. DisclosuresNo relevant conflicts of interest to declare.

Interaction of the B Cell-specific Transcriptional Coactivator OCA-B and Galectin-1 and a Possible Role in Regulating BCR-mediated B Cell Proliferation

OCA-B is a B cell-specific transcriptional coactivator for OCT factors during the activation of immunoglobulin genes. In addition, OCA-B is crucial for B cell activation and germinal center formation. However, the molecular mechanisms for OCA-B function in these processes are not clear. Our previous studies documented two OCA-B isoforms and suggested a novel mechanism for the function of the myristoylated, membrane-bound form of OCA-B/p35 as a signaling molecule. Here, we report the identification of galectin-1, and related galectins, as a novel OCA-B-interacting protein. The interaction of OCA-B and galectin-1 can be detected both in vivo and in vitro. The galectin-1 binding domain in OCA-B has been localized to the N terminus of OCA-B. In B cells lacking OCA-B expression, increased galectin-1 expression, secretion, and cell surface association are observed. Consistent with these observations, and a reported inhibitory interaction of galectin-1 with CD45, the phosphatase activity of CD45 is reduced modestly, but significantly, in OCA-B-deficient B cells. Finally, galectin-1 is shown to negatively regulate B cell proliferation and tyrosine phosphorylation upon BCR stimulation. Together, these results raise the possibility that OCA-B may regulate BCR signaling through an association with galectin-1.

Galectin-1: A Link Between Tumor Hypoxia and Tumor Immune Privilege

To identify a 15-KDa novel hypoxia-induced secreted protein in head and neck squamous cell carcinomas (HNSCC) and to determine its role in malignant progression. We used surface-enhanced laser desorption ionization time-of-flight mass spectrometry (SELDI-TOF-MS) and tandem MS to identify a novel hypoxia-induced secreted protein in FaDu cells. We used immunoblots, real-time polymerase chain reaction (PCR), and enzyme-linked immunoabsorbent assay to confirm the hypoxic induction of this secreted protein as galectin-1 in cell lines and xenografts. We stained tumor tissues from 101 HNSCC patients for galectin-1, CA IX (carbonic anhydrase IX, a hypoxia marker) and CD3 (a T-cell marker). Expression of these markers was correlated to each other and to treatment outcomes. SELDI-TOF studies yielded a hypoxia-induced peak at 15 kDa that proved to be galectin-1 by MS analysis. Immunoblots and PCR studies confirmed increased galectin-1 expression by hypoxia in several cancer cell lines. Plasma levels of galectin-1 were higher in tumor-bearing severe combined immunodeficiency (SCID) mice breathing 10% O2 compared with mice breathing room air. In HNSCC patients, there was a significant correlation between galectin-1 and CA IX staining (P = .01) and a strong inverse correlation between galectin-1 and CD3 staining (P = .01). Expression of galectin-1 and CD3 were significant predictors for overall survival on multivariate analysis. Galectin-1 is a novel hypoxia-regulated protein and a prognostic marker in HNSCC. This study presents a new mechanism on how hypoxia can affect the malignant progression and therapeutic response of solid tumors by regulating the secretion of proteins that modulate immune privilege.

Increased expression of galectin-1 in carcinoma-associated stroma predicts poor outcome in prostate carcinoma patients.

Galectin-1, a member of the beta-galactoside-binding galectin family, is a pleiotropic dimeric protein participating in a variety of normal and pathological processes, including cancer progression. Modulation of the interactions with the basement membrane glycoprotein laminin and induction of apoptosis in activated T lymphocytes are well-known functions of this galectin. In this study, the expression of galectin-1 was examined in 148 human primary prostate carcinoma samples. Immunohistochemical staining of paraffin sections of prostate tissues revealed that galectin-1 was not detected in normal, PIN (prostatic intraepithelial neoplasia) or carcinoma cells, but accumulated in the stroma and associated fibroblasts. Galectin-1 expression was significantly increased in the tumour-associated stroma compared with the non-neoplastic gland-associated stroma in 21.3% of the cases (Mantel-Haenszel test, p=0.001; Wilcoxon signed rank test, p<0.0001). Increased galectin-1 expression in the cancer-associated stroma compared to the normal gland-associated stroma (p=0.03) was identified by multivariate analysis as a strong independent predictor of prostate-specific antigen (PSA) recurrence, just after the pathological stage (p<0.0001). The association between accumulation of galectin-1 in the stroma of the malignant tissue and aggressiveness of the tumour adds weight to the body of evidence that identifies a role for galectin-1 in the acquisition of the invasive phenotype. In addition to modulating cancer cell interactions with laminin, galectin-1 accumulated around the cancer cells may act as an immunological shield by inducing activated T-cell apoptosis. This exciting hypothesis warrants further investigation.

Modulation of galectin-1 content in human head and neck squamous carcinoma cells by sodium butyrate.

Galectin-1 and galectin-3 are beta-galactoside-binding proteins thought to be important for cellular interactions, growth regulation and differentiation. Alterations in cellular content of galectins have been associated with differentiation, transformation and malignant progression. We examined the modulation of galectin-1 and galectin-3 expression in head and neck squamous cell carcinoma (HNSCC) cell lines by treatment with sodium butyrate, a known differentiation-modulating agent, and identified potential mechanisms of butyrate regulation of galectin-1 levels in one of the cell lines. Sodium butyrate effected an increase in galectin-1 protein concentration in 5 of 8 cell lines. One cell line, MDA-886LN, showed a marked time- and dose-dependent increase from barely detectable amounts with butyrate treatment. Concurrently with increased galectin-1 expression, butyrate treatment promoted morphologic changes, induced growth inhibition and inhibited soft agar colony formation in MDA-886LN cells. Butyrate-treated MDA-886LN cells demonstrated increased galectin-1 mRNA content, suggesting a role for butyrate in transcriptional regulation of galectin-1 expression. Treatment with other inhibitors of histone deacetylase also induced an increase in galectin-1 expression. Together, our results indicate that butyrate treatment can modulate galectin-1 content in MDA-886LN HNSCC cells as well as induce morphologic changes and growth inhibition. This action may involve a combination of transcriptional regulation and inhibition of histone deacetylation.