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Targeting galectin-driven regulatory circuits in cancer and fibrosis
Abstract
Galectins are a family of endogenous glycan-binding proteins that have crucial roles in a broad range of physiological and pathological processes. As a group, these proteins use both extracellular and intracellular mechanisms as well as glycan-dependent and independent pathways to reprogramme the fate and function of numerous cell types. Given their multifunctional roles in both tissue fibrosis and cancer, galectins have been identified as potential therapeutic targets for these disorders. Here, we focus on the therapeutic relevance of galectins, particularly galectin 1 (GAL1), GAL3 and GAL9 to tumour progression and fibrotic diseases. We consider an array of galectin-targeted strategies, including small-molecule carbohydrate inhibitors, natural polysaccharides and their derivatives, peptides, peptidomimetics and biological agents (notably, neutralizing monoclonal antibodies and truncated galectins) and discuss their mechanisms of action, selectivity and therapeutic potential in preclinical models of fibrosis and cancer. We also review the results of clinical trials that aim to evaluate the efficacy of galectin inhibitors in patients with idiopathic pulmonary fibrosis, nonalcoholic steatohepatitis and cancer. The rapid pace of glycobiology research, combined with the acute need for drugs to alleviate fibrotic inflammation and overcome resistance to anticancer therapies, will accelerate the translation of anti-galectin therapeutics into clinical practice.
... The immune system plays a critical role in the development of kidney fibrosis (Sato and Yanagita 2018;Fu et al. 2022;Marino et al. 2023). Following kidney injury, immune cells such as macrophages, neutrophils, and dendritic cells are activated, releasing pro-inflammatory cytokines and chemokines that recruit additional immune cells to the injury site (Chen et al. 2018;Singbartl et al. 2019). ...
... is one of the most widely expressed members of the galectin protein family in human tissues (Elola et al. 2014), with diverse cellular functions that may influence AKI outcomes (Perez-Moreno et al. 2024a, 2024b. Its effects may complement or counteract those of other galectins implicated in inflammation and fibrosis (Marino et al. 2023). As a glycan-binding protein of the tandem-repeat type of galectins, Gal-8 possesses two carbohydrate recognition domains (CRDs) separated by a linker peptide of variable length, each exhibiting distinct carbohydrate-binding preferences (Ideo et al. 2011;Cagnoni et al. 2020). ...
... Our results show that Gal-8 expression decreases after AKI and remains lower for at least 14 days, contrasting with other galectins, such as Gal-1, Gal-3, and Gal-9, which have been reported to increase during injury (Vansthertem et al. 2010;Kolatsi-Joannou et al. 2011;Prud'homme et al. 2019;Volarevic et al. 2019;Kulow et al. 2024). Among these, Gal-3 is the most studied and has been implicated in either protective (Volarevic et al. 2019;Kulow et al. 2024) or pro-fibrotic effects after kidney damage (Henderson et al. 2008;Kolatsi-Joannou et al. 2011;Martinez-Martinez et al. 2016;Li et al. 2018;Volarevic et al. 2019;Hermenean et al. 2022;Marino et al. 2023;Perez-Moreno et al. 2024a), depending on the model studied. Similar to our findings, increased renal damage in Gal-3 KO mice has been linked to an inflammatory phenotype characterized by elevated infiltration of Th1 and Th17 lymphocytes (Volarevic et al. 2019). ...
Background
Acute kidney injury (AKI) is a serious clinical condition characterized by a rapid decline in renal function, often progressing to chronic kidney disease (CKD) and fibrosis. The endogenous mechanisms influencing kidney injury resolution or maladaptive repair remain poorly understood. Galectin-8 (Gal-8), a tandem-repeat β-galactoside-binding lectin, plays a role in epithelial cell proliferation, epithelial-mesenchymal transition, and immune regulation, all of which are critical in AKI outcomes. While exogenous Gal-8 administration has shown renoprotective effects, its endogenous role in kidney injury progression and resolution remains unclear.
Methods
To investigate the endogenous role of Gal-8 in AKI, we compared the responses of Gal-8 knockout (Gal-8-KO; Lgals8 −/− bearing a β-gal cassette under the Lgals8 gene promoter) and wild-type ( Lgals8 + / + ) mice in a nephrotoxic folic acid (FA)-induced AKI model. Renal Gal-8 expression was assessed by β-galactosidase staining, lectin-marker colocalization, and RT-qPCR. Renal function, structure, and immune responses were evaluated at the acute (day 2) and fibrotic (day 14) phases of injury. Plasma creatinine levels were measured to assess renal function, while histological analyses evaluated tubular damage, renal inflammation, and extracellular matrix deposition. Flow cytometry was performed to characterize the immune response, focusing on pro-inflammatory T cells.
Results
Galectin-8 was predominantly expressed in the renal cortex, localizing to tubules, glomeruli, and blood vessels, with its levels decreasing by half following AKI. Both Lgals8 + / + and Lgals8 −/− mice exhibited similar renal function and structure impairments during the acute phase, though Lgals8 + / + mice showed slightly worse damage. By the fibrotic phase, Lgals8 −/− mice exhibited more pronounced cortical damage and fibrosis, characterized by increased type I and III collagen deposition and enhanced Th17 cell infiltration, while myofibroblast activation remained comparable to that of Lgals8 + / + mice.
Conclusions
Endogenous Gal-8 does not significantly protect the kidney during the acute phase and is dispensable for cell proliferation and death in response to AKI. However, it is crucial in preventing maladaptive repair by regulating extracellular matrix homeostasis and mitigating fibrosis. Additionally, Gal-8 contributes to inflammation resolution by limiting persistent immune cell infiltration, particularly IL-17-secreting cells.
... The latter structure gives way to galectin-3 molecules with multivalent CRDs that form lattice on the cell surface facilitating cell adhesion and activation [59][60][61][62]. Of note, dimeric and oligomeric structures regulate innate and adaptive responses and promote angiogenesis [54,59,[63][64][65][66][67][68][69]. Nevertheless, to the best of our knowledge, studies involving the endothelial TLR4 activation by specific ligands and their contribution to the small blood vessels (vasculature) formation in angiolipoma, has not been considered. ...
... Consistent with this, studies on galectin-3 have suggested that this glycan-binding protein has a great affinity for the β-galactoside residues present in the TLR4 and TLR2 ectodomains regulating innate and adaptive responses and promoting inflammatory response and angiogenesis [54,58]. Remarkably, studies have point to the involvement of galectin-3 in the leukocyte recruitment in-vivo and angiogenesis [54,59,[63][64][65][66][67][68][69]. Furthermore, galectin-3 oligomerization upon binding to glycoconjugates containing β-galactoside residues on EC surface such as Synd-1, CD44, ICAM-1, VCAM-1, VE-cadherin, N-cadherin, PECAM-1 and endoglin has been proposed, suggesting a critical role for galectin-3 in endothelial morphogenesis and angiogenesis [59,65,68,80]. ...
... Furthermore, galectin-3 oligomerization upon binding to glycoconjugates containing β-galactoside residues on EC surface such as Synd-1, CD44, ICAM-1, VCAM-1, VE-cadherin, N-cadherin, PECAM-1 and endoglin has been proposed, suggesting a critical role for galectin-3 in endothelial morphogenesis and angiogenesis [59,65,68,80]. This is interesting if we consider that published evidence indicates that galectin-3 oligomerization can generate galectin-lattices on the endothelial surface and ICS which facilitate endothelial activation, migration, proliferation and tubule-like structures formation [68,69,[80][81][82]. What is more, the glycoconjugates above mentioned, including fibrinogen, in addition to being assumed as endogenous ligands and activators of endothelial TLR4 are also considered as potential binding partners for galectin-3, as they contain N-and O-linked glycan residues in their ectodomains [24,25,27,32,80,82]. ...
Angiolipomas are benign subcutaneous nodules characterized by the presence of mature adipocytes intermingled with cluster of small blood vessels, often displaying intraluminal fibrin microthrombi. It is known that fibrinogen and/or fibrin intraluminal and extracellular deposition during immune responses affect Endothelial Cell (EC) functioning and leukocyte trafficking. Also, it is known that Toll-Like Receptors (TLRs) are not only expressed in Immune Cells (ICs) but also in ECs and that excessive endothelial activation through TLR interactions with endogenous ligands such as fibrinogen, Heparan Sulfate Proteoglycans (HSPGs), Fibronectin (FN), Tenascin-C (TN-C), hyaluronan and galectin-3, contributes to EC dysfunction promoting endothelial proliferation, migration, apoptosis and tube-like structures formation. Nevertheless, studies involving the endothelial TLR4 activation by specific ligands and their contribution to the small blood vessels formation in angiolipoma has not been considered. Herein, we show that in angiolipoma TLR4 and some of their ligands such as fibrinogen, FN, HSPGs including agrin, perlecan and Synd-1 and galectin-3 as well as some glycoconjugates associated to these ligands including VE-cadherin, VCAM-1, ICAM-1, PECAM-1, endoglin and CD44 were immunolocalized in the ECs from the small vessels and some ICs. We propose that in angiolipoma tissues galectin-3 oligomerization upon binding to these TLR4 endogenous ligands and glycoproteins associated can lead to the formation of gal-glycan lattices on the endothelial surface that might be facilitating not only the activation of TLR4, but also contributing to the vasculature formation regulated by signaling pathways mediated by certain cytokines, chemokines and growth factors.
... 71 GALECTIN, an S-type lectin, encompasses a family of molecules that includes GAL-1, −2, −3, −5, −7, −8, −9, and −10, among others. 72 Notably, GAL-1 and GAL-3 have been implicated in the development of fibrosis based largely on studies in galectin-deficient mice. 73,74 TD139, a Gal-3 inhibitor, has shown antifibrotic efficacy in preclinical models of pulmonary fibrosis and in patients with IPF. ...
... 73,74 TD139, a Gal-3 inhibitor, has shown antifibrotic efficacy in preclinical models of pulmonary fibrosis and in patients with IPF. 69,70,72 Consequently, variations in PANoptosis activity within macrophages may influence other cell types, thereby modulating IPF progression through these specific pathways. ...
Purpose
Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease. PANoptosis, a unique inflammatory programmed cell death, it manifests as the simultaneous activation of signaling markers for pyroptosis, apoptosis, and necroptosis. However, research on the role of PANoptosis in the development of IPF is currently limited. This study was aimed to explore the role of PANoptosis in IPF.
Methods
In this study, we first identified PANDEGs using the GEO database. Exploring potential biological functions and immune cell infiltration abundance through GO/KEGG enrichment analysis and Immune infiltration analysis. Through machine learning and experimental validation, we identified four diagnostic genes and four prognostic genes associated with PANoptosis, leading to the development of a diagnostic and prognostic model for IPF. Our single-cell analysis further explored the role of these PANoptosis prognostic genes. Additionally, the L1000FWD application was used to identify small molecule drugs, based on the four PANoptosis prognostic genes, and confirmed their efficacy through molecular docking.
Results
104 PANoptosis differentially expressed genes were identified from IPF and normal tissues. Enrichment analysis indicated that these genes were associated with immune-inflammatory response pathway. We developed a diagnostic and prognostic models based on PANoptosis related genes. The diagnostic model included AKT1, PDCD4, PSMA2, and PPP3CB. Conversely, the prognostic model included TNFRSF12A, DAPK2, UACA, and DSP. External dataset validation and qPCR showed the reliability of most of the conclusions. Additionally, potential therapeutic drugs, including Metergoline, Candesartan, and Selumetinib, were identified based on four prognostic genes. Molecular docking shows that these drugs have good binding ability with their targets.
Conclusion
Importantly, our findings provide scientific evidence for the diagnosis and prognostic biomarkers of IPF patients, as well as small molecule therapeutic drugs.
... Given that clinical trials targeting EGFR have been widely conducted in esophageal cancer [30], LGALS1 emerged as a key gene associated with drug resistance. LGALS1, a member of the galactoside-binding protein family, is involved in regulating tumor proliferation, immune escape, resistance to apoptosis and angiogenesis [31]. It is broadly expressed across various tumors and is associated with poor prognosis [32]. ...
... LGALS1, we constructed a PPI network for LGALS1 ( Figure S4A). Enrichment analysis revealed that LGALS1 is involved in epithelial-mesenchymal transition (EMT), cell adhesion, growth signalling and cytokine interactions, consistent with previous findings [31] (Figure S4B). GSEA analysis of 179 patients with ESCC from GSE53625 further indicated that high LGALS1 expression is associated with pathways related to apoptosis and DNA repair (Figure S4C), supporting its role in cisplatin resistance. ...
Background Neoadjuvant chemoradiotherapy (neoCRT) remodels the tumor microenvironment in esophageal squamous cell carcinoma (ESCC). This study aimed to analyze the impact of neoCRT on the immune landscape of ESCC and identify potential resistance genes using single-cell RNA-seq (scRNA-seq). Methods We obtained scRNA-seq datasets of ESCC from the GEO database and evaluated changes in the number and function of key T cells and myeloid cells following neoCRT. Malignant epithelial cells were analyzed using inferCNV and subjected to differential analysis to identify potential drug-resistance genes. The gene LGALS1, implicated in drug resistance, was further investigated. The effects of short hairpin RNA knockdown of LGALS1 on cisplatin sensitivity were assessed both in vitro and in vivo. Additionally, potential resistance pathways were explored through a protein-protein interaction network and gene set enrichment analysis. Results NeoCRT treatment resulted in the activation of T cells and myeloid cells within the tumor microenvironment, enhancing the anti-tumor immune response and improving tumor cell eradication compared to the surgery group. However, neoCRT simultaneously increased LGALS1 expression in tumor cells, which contributed to the development of drug resistance. Mechanistically, LGALS1 overexpression was associated with increased platinum resistance, enhanced DNA repair, resistance to apoptosis and epithelial-mesenchymal transition. Conclusion scRNA-seq analysis revealed that neoCRT significantly alters the immune landscape of ESCC. While neoCRT activates T cells and myeloid cells to target tumor cells effectively, it also induces LGALS1 overexpression, which contributes to drug resistance and potential relapse.
... Based on these findings, the involvement of Gal1 in stromal cell responses under pathological conditions needs to be further explored in the choroid. In this regard, Gal1 has recently been proposed to be a critical soluble factor capable of regulating tumor-stroma crosstalk, proliferation, angiogenesis, and inflammatory responses, leading to enhanced tumor progression and metastasis [58,59]. Indeed, Gal1 expression by stromal cells has been described during endometriosis [60] and tumor progression [58,61,62]. ...
Outer retinal function depends on two supporting tissues: the retinal pigment epithelium (RPE) and the choroid. Limited molecular information is available on the intercellular networks that sustain RPE/choroid tissue in both healthy and pathological states. Galectin‐1 (Gal1), a β‐galactoside‐binding lectin, has recently emerged as a key regulator of angiogenesis and a potential therapeutic target in vascular pathologies, including age‐related macular degeneration. Here, we studied the expression of Gal1 in the outer retina and its regulatory role in the RPE/choroid under physiological and pathological conditions. Our findings indicate that Gal1 is predominantly associated with stromal cells in the RPE/choroid. In Gal1‐deficient (Lgals1−/−) mice, the RPE/choroid ultrastructure and gene expression profiles were altered, and choroidal explants exhibited reduced sprouting compared to those of wild‐type mice. Consistently, recombinant Gal1 promoted choroidal sprouting under hypoxic conditions, and stromal‐like cells modulated pro‐angiogenic and antiangiogenic gene expression in vitro under pathological conditions. Interestingly, Gal1 was also expressed by the RPE, with apical secretion under normoxia that shifted toward a basolateral phenotype under hypoxia. These findings identify stromal‐like cells and RPE as key sources of Gal1 in the choroid, highlighting its distinct roles in maintaining RPE/choroid homeostasis in healthy or pathological microenvironments.
... Importantly, this work suggests therapeutic opportunities for reprogramming the TME by targeting nuclear Gal1 to shift PSCs from an activated to a quiescent state. Current Gal1-targeted therapies primarily focus on extracellular functions by using glycan inhibitors, natural polysaccharides, allosteric peptide antagonists, and monoclonal antibodies ( 80 ). However, these approaches mainly target the extracellular roles of galectins in the TME ( 80 , 81 ), without addressing Gal1's nuclear activity. ...
Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive cancers, primarily due to its complex tumor microenvironment (TME), which drives both disease progression and therapy resistance. Understanding the molecular mechanisms governing TME dynamics is essential for developing new treatment strategies for this devastating disease. In this study, we uncover an oncogenic role for Galectin-1 (Gal1), a glycan-binding protein abundantly expressed by activated pancreatic stellate cells (PSCs), a key component of the PDAC TME that orchestrates tumor progression. Our findings reveal that Gal1 expression is elevated in the nucleus of human PSCs in both tissue samples and cultured cell lines. Using chromatin immunoprecipitation followed by sequencing analysis (ChIP-seq), we identify Gal1 occupancy at the promoters of several cancer-associated genes, including KRAS , a pivotal oncogene involved in PDAC pathogenesis. We demonstrate that Gal1 binds to the KRAS promoter, sustaining KRAS expression in PSCs, which, in turn, maintains PSC activation and promotes the secretion of protumorigenic cytokines. Mechanistically, Gal1 is required to preserve histone H3 lysine 4 monomethylation levels and to recruit the histone methyltransferase MLL1 to target promoters. Collectively, our findings define a nuclear function of Gal1 in modulating the transcriptional landscape of cancer-associated genes in PSCs within the PDAC TME, mediated through an epigenetic mechanism. These insights enhance our understanding of PDAC pathology and open potential avenues for therapeutic interventions targeting intracellular Gal1.
... Polysaccharides are complex polymer with large molecular structures that are found throughout nature [11]. Natural bioactive polysaccharides exhibit versatile activities, including immunomodulator [12], antiinflammatory [13], antiviral [14], antioxidant [15], and anticancer [16] effects, making them a promising therapeutic source [17]. It was reported that the carbohydrate components made up about 30% of the total crude mass of S. baicalensis [18]. ...
Background
Polysaccharides were extracted from the roots of Scutellaria baicalensis Georgi using hot water and ethanol precipitation method. The SBP-1 and SBP-2, were obtained after eluting from DE-52 column. The molecular weight, monosaccharide composition and linkage types of SBP-1 and SBP-2 were determined by the high performance gel permeation chromatography, high-performance anion exchange chromatography, gas chromatography–mass spectroscopy and NMR spectra.
Results
SBP-1 and SBP-2 were characterized as a homogenous polysaccharide with Mw of 80.5 and 25.8 kDa, respectively. Moreover, there were seven linkage types in the SBP-1 and it was a type II arabinogalactan formed by a (1→6)-linked β-d-Galp main chain. Whereas, except for the linkage types of α-l-Araf-(1→, →5)-α-l-Araf-(1→ and →3,5)-α-l-Araf-(1→, the SBP-2 enriched with →3,4)-α-d-GalpA-(1→, →4)-α-d-GalpA-(1→ and →4)-α-d-GalpA(OMe)-(1→, indicating the pectic type arabinogalacturonan structure. Moreover, both SBP-1 and SBP-2 exhibited immunoregulatory effects on RAW 264.7 cells by modulating the toll-like receptor (TLR) signaling pathway, as demonstrated through RNA-seq analysis, western blotting, immunoprecipitation (IP) experiments, and surface plasmon resonance (SPR) analysis.
Conclusions
These findings suggest an immunological basis for the therapeutic potential of S. baicalensis.
Graphical Abstract
... Гал регулируют трансмембранную передачу сигналов, межклеточные контакты и адгезию различных патогенов, то есть процессы, которые играют значимую роль в защите от инфекций и онкогенезе. Кроме того, углевод-зависимые и углевод-независимые взаимодействия Гал с цитозольными или ядерными мишенями вносят определенный вклад в сплайсинг матричной рибонуклеиновой кислоты и экспрессию генов [5][6][7]. ...
The study of galectins is provoked by the search for new biomarkers of activity, clinical manifestations, and disease outcomes of systemic lupus erythematosus (SLE). The presented literature review summarizes the data on the most well-known galectins-1, -3, -9, as well as antibodies to galectins and galectin-3-binding protein, obtained in culture studies, in animal models of lupus and in patients with SLE.
... Therefore, as tools for glycobiological studies and as potential therapeutic agents, these glycomimetics are more attractive than the in vivo labile natural glycosides. [5][6][7] The synthesis of S-linked glycomimetics represents different levels of difficulty depending on the stereochemistry of the thioglycosidic bonds. Though 1,2-trans-β-thiols and -β-thioglycosides can be easily synthesized via classical nucleophilic substitution reactions by taking advantage of the anchimeric assistance by the C2 acyl group, [4,8] stereocontrolled construction of 1,2-cis-α-thio linkages is difficult and has no general solution. ...
Glycosyl thiols are key building blocks for the formation of stable thioglycoside mimetics of widespread and biologically relevant α‐O‐glycosides, which urges their efficient synthesis. Here, we demonstrate that the photoinitiated radical‐mediated addition of thioacetic acid to 2‐substituted glycals followed by selective S‐deacetylation is a generally applicable and fully stereoselective method for the synthesis of 1,2‐cis‐α‐glycosyl thiols. The low reactivity of thioacetic acid in the radical reaction was overcome by carrying out the reaction in AcOH at −80 °C, in frozen state, with UVA irradiation, achieving high yields irrespective of the sugar configurations. For effective irradiation and simultaneous effective cooling, a self‐made spiral vessel reactor was used, which also enables large‐scale synthesis. By subjecting 1,2‐cis‐α‐1‐thiosugars to a second thiol‐ene coupling reaction with 2‐substituted glycals, 34 trehalose‐type symmetrical and unsymmetrical α,α’‐thiodi‐ and oligosaccharides were obtained with full stereoselectivity. Moreover, the oxidation of α‐1‐thiosugars provided an easy access to α,α’‐diglycosyl disulfides.
... Gal-9 protein, a promising immunotherapeutic agent, is used to modulate immune responses and manage immune-related disorders (Qi et al., 2019;Zhang et al., 2019a;Rodrigues Mantuano et al., 2020;Marino et al., 2023). It has been indicated that Gal-9 can influence endothelial cell growth, migration, and luminal formation, consequently promoting angiogenesis (Tang et al., 2019). ...
Background
Peri-implantitis (PI) is a common complication of oral implants with no definitive treatment strategy. Lipopolysaccharides (LPS) are involved in PI by activating macrophages and influencing osteoclasts and osteoblasts. Galactin-9 (Gal-9) is known for its immunomodulatory properties and interactions with macrophage polarization receptors. This study investigated the mechanism of prophylactic exogenous Gal-9 in the prevention and treatment of PI in rats.
Methods
Male SD rats with titanium implants were divided into the Control, Saline, and Gal-9 groups. Rats in the Saline group and Gal-9 group were prophylactically administered Gal-9 and Saline, respectively, before inducing PI. Periodontal examinations, X-ray imaging, flow cytometry analyses, and micro-CT evaluations were conducted to assess clinical, imaging, and immunological parameters.
Results
After inducing PI, the implant loss rate in the Gal-9 group was lower than that in the Saline group. The gingival index was higher in the Saline group and Gal-9 group compared to the Control group. The bleeding on probing positivity rate was higher in the Saline group than in the other two groups. X-ray and micro-CT images both showed lower alveolar bone resorption in the Gal-9 group than in the Saline group. Flow cytometry showed that the proportions of M1-type macrophages and M2-type macrophages, and M1/M2 ratio were lower in the Gal-9 group than those in the Saline group. Multivariate linear regression indicated that Tb.Th had the greatest impact on the gingival index and Tb.Sp had the greatest impact on the M1/M2 ratio.
Conclusion
Exogenous Gal-9 administration demonstrated promising effects in mitigating inflammation associated with PI in rat models by promoting M2 macrophage polarization and enhancing alveolar bone stability.
... Following these results, an international adaptive phase 2b/3 trial (NCT04365868) was initiated to further investigate its clinical benefits in preventing esophageal varices based on endoscopic evaluations [175]. GB1107, a small-molecule thiogalactoside inhibitor targeting the CRD of galectin-3, is also under investigation [176,177]. GB1107 s analog, GB1211, is being evaluated in a phase 2 study (NCT04607655) for cirrhosis across various etiologies in a first-in-human trial [178]. ...
In recent years, “metabolic dysfunction-associated steatotic liver disease” (MASLD) has been proposed to better connect liver disease to metabolic dysfunction, which is the most common chronic liver disease worldwide. MASLD affects more than 30% of individuals globally, and it is diagnosed by the combination of hepatic steatosis and obesity, type 2 diabetes, or two metabolic risk factors. MASLD begins with the buildup of extra fat, often greater than 5%, within the liver, causing liver hepatocytes to become stressed. This can proceed to a more severe form, metabolic dysfunction-associated steatohepatitis (MASH), in 20–30% of people, where inflammation in the liver causes tissue fibrosis, which limits blood flow over time. As fibrosis worsens, MASH may lead to cirrhosis, liver failure, or even liver cancer. While the pathophysiology of MASLD is not fully known, the current “multiple-hits” concept proposes that dietary and lifestyle factors, metabolic factors, and genetic or epigenetic factors contribute to elevated oxidative stress and inflammation, causing liver fibrosis. This review article provides an overview of the pathogenesis of MASLD and evaluates existing therapies as well as pharmacological drugs that are currently being studied in clinical trials for MASLD or MASH.
... These proteins belong to the ErbB (EGFR), immunoglobulin-like (CD146, CD44), integrin (Integrin), intermediate filament (vimentin), calcium-dependent membrane-binding (Annexin A1, A2, and A5), and lectin (Galectin) families of proteins, and have been reported as overexpressed biomarkers in HeLa and MDA cells [21,38,39,41,42]. Altered or mutant expression of these biomarkers accounts for cancer cells' pathogenesis and progression, leading to cell proliferation, angiogenesis, invasion, metastasis, and inhibition of apoptosis [38,39,43,[45][46][47][48]]. ...
Peptides binding overexpressed breast and cervical cancer cell surface proteins can be isolated by phage display technology, and their affinity to their potential receptors can be assessed by molecular docking. We isolated 44 phage clones displaying dodecapeptides with high affinity to HeLa cervical cancer and MDA‐MB‐231 (MDA) breast cancer cells by repeated biopanning of an MK13 phage library and explored their affinity to specific proteins by molecular docking. Six peptides appeared repeatedly during biopanning: two with affinity to HeLa (H5/H21), and four with affinity to MDA cells (M3/M7/M15/M17). Peptide pairs M3/H5 and H1/M17 had affinity to both cell lines. A systematic review identified Annexin A2, EGFR, CD44, CD146, and Integrin alpha V as potential protein targets in HeLa cells, and Vimentin, Galectin‐1, and Annexins A1 and A5 in MDA cells. Via virtual screening, we selected six peptides with the highest total docking scores: H1 (−916.32), H6 (−979.21), H19 (−1093.24), M6 (−732.21), M16 (−745.5), and M19 (−739.64), and identified that docking scores were strengthened by the protein type, the interacting amino acid side chains, and the polarity of peptides. This approach facilitates the selection of relevant peptides that could be further explored for active targeting in cancer diagnosis and treatment.
... Galectins are a family of b-galactoside-binding lectins with essential roles in various biological processes, such as tissue repair, adipogenesis, immune cell homeostasis, angiogenesis, and pathogen recognition (1,2). Notably, altered expression of galectins or disruptions in their interactions with glycan partners are associated with a wide range of pathological conditions, including cancer, autoimmune inflammation, infections, fibrosis, and metabolic disorders (3,4). Particularly, research on galectin-3 (Gal-3), a member of the galectin family, primarily targets its inhibition due to its role in promoting cancer and metastasis, presenting the potential for anticancer therapy (5,6). ...
... The glycocalyx and extracellular matrix (ECM) form a complex network of glycoproteins, proteoglycans, water, and various macromolecules that enable cell-cell interactions and maintain structural integrity within different tissues 31,32 . In a diseased state, such as in cancer and chronic inflammation, glycosylation patterns as well as the ECM microenvironment are altered, resulting in the development of glycan epitopes for galectin binding 33 . Thus, galectin-functionalized microgels may be efficiently targeted to the cell surface by exploiting the βgalactosyl binding capabilities of galectins. ...
The inherent carbohydrate-binding specificities of human galectins can serve as recognition elements in both biotechnological and biomedical applications. The combination of the carbohydrate-recognition domain (CRD) of galectins fused to peptides...
... The interaction between the β-galactoside-binding carbohydrate recognition domain (~14 kDa region) of gal-3 and the β-galactoside-rich CP is generally known to possess a dissociation constant (K D ) in the range of 50-100 μM. 26,[84][85][86][87] With the ubiquitous expression of gal-3 on the surface of fibroblasts (among other pulmonary cell populations), and the upregulation of this expression during fibrosis, the increased binding of CP (aided by its nanoscale presentation in this case) during TGFβ-induced fibrosis and with increasing CP-PLGA NP dose fits in with the behaviour predicted by extant literature. [17][18][19][20][21] Evaluation of NP uptake by seeding density-matched model pulmonary epithelial cells (A549s; Fig, 5A-ii) showed uptake by these cells occurred at an order of magnitude lower than fibroblasts, with epithelial cells exposed to pro-fibrotic TGFβ taking up more of the particles than non-exposed controls. ...
Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial disorder of the respiratory system that can be debilitating as it progresses and has experienced a slow rise in incidence in past...
... The first type is carbohydrate-modified azocalix [4]arenes. The mannose receptor, galactose receptor, and β-glucan receptor expressed by macrophages [49][50][51][52] , along with lectins, toxins, and adhesins present on bacteria 53,54 , can recognize carbohydrates. The second type is amino acid-modified azocalix [4]arenes. ...
Pathogenic intracellular bacteria pose a significant threat to global public health due to the barriers presented by host cells hindering the timely detection of hidden bacteria and the effective delivery of therapeutic agents. To address these challenges, we propose a tandem diagnosis-guided treatment paradigm. A supramolecular sensor array is developed for simple, rapid, accurate, and high-throughput identification of intracellular bacteria. This diagnostic approach executes the significant guiding missions of screening a customized host-guest drug delivery system by disclosing the rationale behind the discrimination. We design eight azocalix[4]arenes with differential active targeting, cellular internalization, and hypoxia responsiveness to penetrate cells and interact with bacteria. Loaded with fluorescent indicators, these azocalix[4]arenes form a sensor array capable of discriminating eight intracellular bacterial species without cell lysis or separation. By fingerprinting specimens collected from bacteria-infected mice, the facilitated accurate diagnosis offers valuable guidance for selecting appropriate antibiotics. Moreover, mannose-modified azocalix[4]arene (ManAC4A) is screened as a drug carrier efficiently taken up by macrophages. Doxycycline loaded with ManAC4A exhibits improved efficacy against methicillin-resistant Staphylococcus aureus-infected peritonitis. This study introduces an emerging paradigm to intracellular bacterial diagnosis and treatment, offering broad potential in combating bacterial infectious diseases.
... The analysis of intercellular communication revealed that T cells engaged in direct and robust interactions with different cell subtypes, facilitated by LAMININ, and GALECTIN signaling pathways. GALECTIN pathway have a broad influence on tumour progression via glycosylation-dependent or independent mechanisms that modulate proliferation, evasion of growth suppressors and immune responses, resistance to cell death, induction of angiogenesis, inflammation and metastasis (Mariño et al. 2023). Laminin can bind to integrins in the extracellular matrix, promote tumor invasion and metastasis, evade apoptosis and stimulate angiogenesis (Stewart and O'Connor 2015). ...
Background
T cells are involved in every stage of tumor development and significantly influence the tumor microenvironment (TME). Our objective was to assess T-cell marker gene expression profiles, develop a predictive risk model for human papilloma virus (HPV)-negative oral squamous cell carcinoma (OSCC) utilizing these genes, and examine the correlation between the risk score and the immunotherapy response.
Methods
We acquired scRNA-seq data for HPV-negative OSCC from the GEO datasets. We performed cell‒cell communication, trajectory, and pathway enrichment analyses of T-cell-associated genes. In addition, we constructed and validated a T-cell-associated gene prognostic model for HPV-negative OSCC patients using TCGA and GEO data and assessed the immune infiltration status of HPV-negative OSCC patients .qRT-PCR was used to detect the expression level of prognosis-related genes in different risk groups.
Results
ScRNA-seq was conducted on 28,000 cells derived from 14 HPV-negative OSCC samples and 6 normal samples. We identified 4,635 T cells from these cells and identified 774 differentially expressed genes(DEGs) associated with T cells across five distinct T-cell subtypes. Through the integration of bulk-RNAseq data, we established a prognostic model based on DEGs related to T cells. By separating patients into high-risk and low-risk groups according to these prognostic related genes, we can accurately predict their survival rates and the immune infiltration status of the TME.qRT-PCR results showed that compared with the patients of low risk group, the expression of PMEPA1, SH2D2A, SMS and PRDX4 were significantly up-regulated in high risk group.
Conclusion
This study provides a resource for understanding the heterogeneity of T cells in HPV-negative OSCC patients and associated prognostic risk models. It provides new insights for predicting survival and level of immune infiltration in patients with HPV-negative OSCC.
... Despite the availability of symptomatic supportive clinical treatments, there is still a lack of effective means to slow or reverse the process of fibrosis [5]. The limited understanding of ALI pathogenesis at the molecular level, coupled with the inadequacy of existing therapeutic strategies, has resulted in a high mortality rate in patients with ALI [6]. Therefore, an in-depth exploration of the mechanisms underlying the onset and development of ALI-induced PF at the molecular level is of utmost clinical importance to improve the therapeutic outcome of ALI/ARDS. ...
Background
Sepsis is a systemic inflammatory response caused by infection. When this inflammatory response spreads to the lungs, it can lead to acute lung injury (ALI) or more severe acute respiratory distress syndrome (ARDS). Pulmonary fibrosis is a potential complication of these conditions, and the early occurrence of pulmonary fibrosis is associated with a higher mortality rate. The underlying mechanism of ARDS-related pulmonary fibrosis remains unclear.
Methods
To evaluate the role of mast cell in sepsis-induced pulmonary fibrosis and elucidate its molecular mechanism. We investigated the level of mast cell and epithelial-mesenchymal transition(EMT) in LPS-induced mouse model and cellular model. We also explored the influence of cromolyn sodium and mast cell knockout on pulmonary fibrosis. Additionally, we explored the effect of MC-derived IL-13 on the EMT and illustrated the relationship between mast cell and pulmonary fibrosis.
Results
Mast cell was up-regulated in the lung tissues of the pulmonary fibrotic mouse model compared to control groups. Cromolyn sodium and mast cell knockout decreased the expression of EMT-related protein and IL-13, alleviated the symptoms of pulmonary fibrosis in vivo and in vitro. The PI3K/AKT/mTOR signaling was activated in fibrotic lung tissue, whereas Cromolyn sodium and mast cell knockout inhibited this pathway.
Conclusion
The expression level of mast cell is increased in fibrotic lungs. Cromolyn sodium intervention and mast cell knockout alleviate the symptoms of pulmonary fibrosis probably via the PI3K/AKT/mTOR signaling pathway. Therefore, mast cell inhibition is a potential therapeutic target for sepsis-induced pulmonary fibrosis.
... Extensive studies have been conducted on the subsite binding specificity [14][15][16][17][18][19][20], tissue-specific expression patterns, and the functional roles of various galectins in host defense responses, including in maintaining tissue integrity [41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57]. Notably, when Fig. 3, which illustrates subsite specificity, is adjusted to compare the relative binding affinities of galectins on a unified Y-axis (Fig. 5), a question arises as to why certain galectins, such as galectin-3, galectin-8 N-CRD, and galectin-9, exhibit relatively high affinities, while galectin-1, galectin-4, and galectin-8 C-CRD show notably lower affinities. ...
... In particular, we have selected human galectin-7 (Gal-7) [24] for the NMR experiments inside the cell as model lectin. As mentioned above, galectins [25][26][27] can be found in the cytosol, besides the nucleus, outer plasma membrane, and the extracellular matrix. As all galectins, galectin-7 binds β-galactosides and it has been reported that prefers those presented at the terminal non-reducing end of Nglycans. ...
Glycan‐mediated molecular recognition events are essential for life. NMR is widely used to monitor glycan binding to lectins in solution using isolated glycans and lectins. In this context, we herein explore diverse NMR methodologies, from both the receptor and ligand perspectives, to monitor glycan‐lectin interactions under experimental conditions mimicking the native milieu inside cells and on cell surface. For the NMR experiments inside cells, galectin‐7 is employed as model, since most galectins are soluble and carry out their functions in the cellular micro‐environment. Using Danio Rerio oocytes, the ¹H‐¹⁵N HMQC NMR spectrum of a folded galectin has been observed inside cell for the first time, using a glycomimetic ligand (TDG) to overcoming the natural tendency of galectins to bind to numerous galactose‐containing receptors within cells. Alternatively, most lectins, other than galectins, are displayed on the cell surface, providing a multivalent presentation to bind their glycan partners in cis (at the same cell) or in trans (on other cells). In this case, ligand‐based STD‐NMR experiments have been successfully applied to account for the interactions of natural glycans and glycomimetics with Siglec‐10. These methodologies provide the proof‐of‐concept to open the door to the NMR analysis of the recognition of glycans in native‐like settings.
... Pedersen et al. reported that PD-1 and Gal-3 can be present on mononuclear cells in blood and synovial fluid and that Gal-3 can inhibit PD-1 signaling when PD-L1 is present (11). Clinical trials on the use of Gal-3 inhibitors to improve the effectiveness of anti-PD-1 therapy for metastatic melanoma and head and neck squamous cell carcinoma are underway (11,89). Much of knowledge of these immunosuppressive molecules has come from murine studies and lot needs to be worked out in human diseases. ...
In recent years, knowledge regarding immune regulation has expanded rapidly, and major advancements have been made in immunotherapy for immune-associated disorders, particularly cancer. The programmed cell death 1 (PD-1) pathway is a cornerstone in immune regulation. It comprises PD-1 and its ligands mediating immune tolerance mechanisms and immune homeostasis. Accumulating evidence demonstrates that the PD-1 axis has a crucial immunosuppressive role in the tumor microenvironment and autoimmune diseases. PD-1 receptors and ligands on immune cells and renal parenchymal cells aid in maintaining immunological homeostasis in the kidneys. Here, we present a comprehensive review of PD-1 immunology in various kidney disorders, including renal cell carcinoma, glomerulonephritis, kidney transplantation, renal aging, and renal immune-related adverse events secondary to PD-1 immunotherapy.
... The intricate relationship between the galectin family and c-MET signaling underscores their pivotal roles in cancer biology. Galectins are involved in various cellular processes, including cell adhesion, migration, and immune modulation, which are critical for tumor progression (25). ...
Cellular mesenchymal-epithelial transition factor (c-MET), also known as hepatocyte growth factor receptor (HGFR), is a crucial receptor tyrosine kinase implicated in various solid tumors, including lung, breast, and liver cancers. The concomitant expression of c-MET and PD-L1 in tumors, such as hepatocellular carcinoma, highlights their prognostic significance and connection to therapeutic resistance. Cancer-associated fibroblasts and mesenchymal stromal cells produce hepatocyte growth factor (HGF), activating c-MET signaling in tumor cells and myeloid-derived suppressor cells (MDSC). This activation leads to metabolic reprogramming and increased activity of enzymes like glutaminase (GLS), indoleamine 2,3-dioxygenase (IDO), and arginase 1 (ARG1), depleting essential amino acids in the tumor microenvironment that are vital for effector immune cell function. This review highlights the interplay between tumor cells and myeloid-derived suppressor cells (MDSCs) that create an immunosuppressive environment while providing targets for c-MET-focused immunotherapy. It emphasizes the clinical implications of c-MET inhibition on the behavior of immune cells such as neutrophils, macrophages, T cells, and NK cells. It explores the potential of c-MET antagonism combined with immunotherapeutic strategies to enhance cancer treatment paradigms. This review also discusses the innovative cancer immunotherapies targeting c-MET, including chimeric antigen receptor (CAR) therapies, monoclonal antibodies, and antibody-drug conjugates, while encouraging the development of a comprehensive strategy that simultaneously tackles immune evasion and enhances anti-tumor efficacy further to improve the clinical prognoses for patients with c-MET-positive malignancies. Despite the challenges and variability in efficacy across different cancer subtypes, continued research into the molecular mechanisms and the development of innovative therapeutic strategies will be crucial.
... Galectins are a family of glycan-binding proteins that are involved in various biological functions (Marino et al., 2023). Recently, galectins have gained increasing recognition for their ability to regulate immune responses in neurological diseases (Vasta, 2009). ...
The accumulation of amyloid‐β (Aβ) and overactivation of microglia contribute to the pathogenesis of Alzheimer's disease (AD), but the interaction between microglial activation and Aβ deposition in AD remains elusive. Here we revealed that Aβ activates microglia and promotes the release of Galectin‐9 (Gal‐9), a member of the β‐galactoside–binding family of lectins. The levels of Gal‐9 in the cerebrospinal fluid and brain tissues of AD patients are higher than those in control subjects. Gal‐9 interacts with Aβ and promotes its aggregation, generating Gal‐9‐Aβ fibrils with enhanced seeding activity and neurotoxicity. The expression of Gal‐9 increases with age in the brains of APP/PS1 transgenic mice. Knockout of Gal‐9 in APP/PS1 mice substantially reduced Aβ sedimentation, neuroinflammation, and cognitive impairment. Moreover, depletion of Gal‐9 inhibited the seeding activity of brain homogenates from APP/PS1 mice. These findings reveal a mechanism by which microglia‐derived Gal‐9 accelerates Aβ aggregation and seeding in AD. Thus, strategies aimed at inhibiting Gal‐9 may hold promise as a disease‐modifying therapy to alleviate AD pathology.
... Galectin-1 (Gal-1), a glycan-binding immunosuppressive mediator, is upregulated in various malignancies, such as head and neck cancer (HNC), lung and pancreatic cancers and gliomas [33][34][35][36] . Its overexpression correlates with tumor hypoxia 37 and heightens tumor aggressiveness and poor survival 38 . ...
Strategies to enhance the anti-tumor immune response of stereotactic ablative radiotherapy (SABR) at primary tumors and abscopal sites are under intensive investigation. Here we report a metabolizable binary supracluster (BSCgal) that combines gold nanoclusters as radiosensitizing adjuvants with small interfering RNA (siRNA) targeting the immunosuppressive mediator galectin-1 (Gal-1). BSCgal comprises reversibly crosslinked cationic gold nanoclusters and siRNA complexes in a polymer matrix that biodegrades over weeks, facilitating clearance (90.3% in vivo clearance at 4 weeks) to reduce toxicity. The particle size well above the renal filtration threshold facilitates passive delivery to tumors. Using mouse models of head and neck cancer, we show that BSCgal augments the radiodynamic and immunotherapeutic effects of SABR at the primary and metastatic tumors by promoting tumor-inhibitory leukocytes, upregulating cytotoxic granzyme B and reducing immunosuppressive cell populations. It outperforms SABR plus Gal-1 antagonists, chemoradiation drug cisplatin or PD-1 inhibitor. This work presents a translatable strategy to converge focal radiosensitization with targeted immune checkpoint silencing for personalized radioimmunotherapy.
... Результаты исследований молекулярных механизмов противоопухолевого иммунитета обосновывают рациональность разработки таргетных подходов терапии рака. Одной их перспективных мишеней, поддерживающих иммуносупрессивное микроокружение опухолевых клеток, являются галектины [1][2][3][4][5][6][7]. Галектин-опосредованные механизмы дисрегуляции иммунных реакций, способствующие опухолевому росту и метастазированию, включают угнетение активации и индукцию апоптоза Т-лимфоцитов, экспансию популяции Foxp3 + Т-регуляторных клеток и их иммуносупрессивной активности, стимуляцию дифференцировки толерогенных дендритных клеток, подавление пула естественных киллеров и поляризацию макрофагов в сторону М2-фенотипа [3,[8][9][10][11]. ...
Aim. To consider the use of galectin-1 and galectin-3 inhibitors as potential pharmacological targets in antitumor and antifibrotic therapy.
The lecture includes the analysis of experimental research and review articles presented in the PubMed database. A brief description of the structure of galectins is given. Their generally accepted classification and features of the structure of the carbohydrate recognition domain in galectin-1 and galectin-3 are presented. The main part of the lecture describes the results of research on the development of carbohydrate-based (β-galactoside derivatives or analogues) and non-carbohydrate-based (peptide-based, carboxamide derivatives) inhibitors capable of interacting with galectin-1 and galectin-3.
The results of experiments performed on animal models and tumor cell cultures demonstrate that the antitumor effect of galectin antagonists is realized through the suppression of proliferation and metastasis, activation of tumor cell apoptosis, and modulation of the antitumor immune response. Antagonists of galectin-1 and galectin-3 potentiate the effect of antitumor drugs and have an antifibrotic effect. Some of the compounds discussed in the lecture are undergoing clinical trials. The data presented in the lecture open up opportunities for the development and synthesis of new molecules of potential galectin-1 and 3 inhibitors.
Galectins play significant roles in regulating immune responses, posing challenges for cancer immunotherapy. The development of galectin inhibitors has been limited by their high structural homology and the lack of noninvasive imaging tools to identify potential responsive patients. We developed 12 galectin-7-specific inhibitors using nanobodies (Nbs) and identified G7N8 as the lead Nb. G7N8 was conjugated with the NOTA chelator, labeled with copper-64 ([⁶⁴Cu]Cu), and used as a radiotracer for PET imaging in a triple-negative breast cancer (TNBC) mouse model. Nbs demonstrated high affinity for galectin-7, with no binding activity for other galectins tested. The lead Nbs inhibited galectin-7 binding to T-cell glycoreceptors and reduced subsequent apoptosis. PET imaging with [⁶⁴Cu]Cu-NOTA-G7N8 showed selective radiotracer accumulation at 20 h (P = 0.001). We developed galectin-7-specific Nbs that inhibit T-cell apoptosis and enable PET imaging of TNBC, providing novel tools for investigating immune regulation and enhancing cancer immunotherapy.
Poly(amidoamine) (PAMAM) dendrimers functionalized with ligands that are designed to interact with biological receptors are important macromolecules for the elucidation and mediation of biological recognition processes. Specifically, carbohydrate functionalized dendrimers are useful synthetic multivalent systems for the study of multivalent protein–carbohydrate interactions. For example, lactose functionalized glycodendrimers can be used to discern the function of galectins, galactoside-binding proteins that are often over-expressed during cancer progression. In order to effectively interpret cancer cellular assays using glycodendrimers, however, their properties in the presence of cells must first be assessed. Macromolecules that are taken up by cells would be expected to have access to many different cell signaling pathways and modes of action that solely extracellular macromolecules cannot utilize. In addition, macromolecules that display cellular toxicity could not be used as drug delivery vehicles. Here, we report fundamental studies of cellular toxicity, viability, and uptake with four generations of lactose functionalized PAMAM dendrimers. In all cases, the dendrimers are readily taken up by the cells but do not display any significant cellular toxicity. The glycodendrimers also increase cellular apoptosis, suggesting that they may abrogate the antiapoptotic protections afforded by galectin-3 to cancer cells. The results reported here indicate that appropriately functionalized PAMAM dendrimers can be used as nontoxic tools for the study and mediation of both extra and intracellular cancer processes.
Galectin‐1, a constituent of the mammalian β‐galactoside‐binding lectin family, plays a pivotal regulatory role in fibrotic cascades. Dysregulated fibrogenic cellular activity has been implicated as a critical driver of hypertrophic scar (HS) pathogenesis. Nevertheless, the precise mechanistic contributions and molecular pathways through which Galectin‐1 modulates HS development remain incompletely characterized. qRT‐PCR and western blot techniques were employed to explore the expression of Galectin‐1 in hypertrophic scar tissues and cells. The Galectin‐1 knockdown cell line was established by utilizing the lentivirus approach, and the influences of Galectin‐1 on cellular biological functions were examined. The molecular mechanism underlying Galectin‐1 regulation was investigated via RNA‐seq analysis, immunofluorescence, and Western blot. Subsequently, RNA‐seq combined with RT‐PCR was used to investigate Galectin‐1's role in HS alternative splicing. Galectin‐1 exhibits significant overexpression in pathological HS tissues and activated fibroblasts. Genetic silencing of Galectin‐1 effectively attenuates hypertrophic scar fibroblast (HSF) cell proliferation, migration, and invasive capacities while downregulating fibrotic molecular markers. Transcriptomic and functional analyses reveal that Galectin‐1 orchestrates concurrent PANoptosis and ferroptosis in fibrogenic cells. Galectin‐1 regulates PANoptosis through the ROS pathway by modulating the ES alternative splicing of NASP, and this process depends on HNRNPL. Overall, Galectin‐1 influences the PANoptosis process in HSF cells by modulating the alternative splicing of NASP, thereby regulating the fibrotic cascade. Our findings indicate that Galectin‐1 is a critical regulator of HS formation, offering a novel therapeutic target and direction for HS treatment.
Chordoma, a rare mesenchymal malignancy, exhibits a high tendency to postoperative recurrence and poor prognosis. To date, its tumorigenic regulatory mechanisms remain elusive, leading to a lack of effective therapeutic targets and drug sensitivity indicators. Here, via transcriptome and proteome analyses, RAB3B is unveiled as a prominent oncogenic regulator in chordoma, with high expression and enhancer‐associated transcriptional activity. Notably, RAB3B ablation attenuated the chordoma cell stemness and malignant biological properties in vivo and in vitro. Through determining the RAB3B‐mediated program in chordoma, it is identified that it enhanced the phosphorylation of S6 specifically at S235/236 and directly bound to S6. Mechanistically, RAB3B physically interacted with phosphorylase DUSP12, and blocked the DUSP12‐mediated dephosphorylation of p‐S6 (S235/236). Pharmacological targeting mTORC1 pathway dramatically impeded the RAB3B‐induced stemness regulation, protein translation, and chordoma tumorigenicity, while RAB3B knockdown desensitized mTORC1 inhibition. In clinic, the combination of RAB3B and p‐S6 suggested a good prognostic value and predicted mTORC1 inhibitors response for chordoma patients. Altogether, this work uncovers RAB3B/DUSP12 as the novel regulators of S6 phosphorylation (S235/236), and suggests the oncogenic and predictive roles of RAB3B/p‐S6 in chordoma, indicating therapeutic potentials of mTORC1‐targeted therapy for advanced chordoma patients with aberrant RAB3B/p‐S6 hyperactivation.
Poly‐N‐acetyllactosamine (poly‐LacNAc) is ubiquitously expressed on cell surface glycoconjugates, serving as the backbone of complex glycans and an extended scaffold that presents diverse glycan epitopes. The branching of poly‐LacNAc, where internal galactose (Gal) residues have β1‐6 linked N‐acetylglucosamine (GlcNAc) attached, forms the blood group I‐antigen, which is closely associated with various physiological and pathological processes including cancer progression. However, the underlying mechanisms remain unclear as many of the I‐antigen sequences are undefined and inaccessible. In this study, we developed a highly efficient orthogonal‐group‐controlled approach to access site‐selectively I‐branched poly‐LacNAc chains. The approach relies on three orthogonal protecting groups, each of them “caps” one internal Gal residue of poly‐LacNAc. These groups can be readily “decapped” by specific enzymes or chemical reduction to expose desired sites for GCNT2‐catalyzed I‐branching. This approach enabled the rapid preparation of a diverse library of 41 linear and branched poly‐LacNAc glycans from a single precursor. Glycan microarray analysis using these complex glycans revealed unique recognitions of I‐branches by lectins, anti‐I mAbs, and galectins. Surprisingly, oxidized forms of linear poly‐LacNAc strongly bound to several glycan‐binding proteins (GBPs). These findings help to bridge the gap in recognition of I‐branching and open new avenues for therapeutic development by targeting galectins.
Poly‐N‐acetyllactosamine (poly‐LacNAc) is ubiquitously expressed on cell surface glycoconjugates, serving as the backbone of complex glycans and an extended scaffold that presents diverse glycan epitopes. The branching of poly‐LacNAc, where internal galactose (Gal) residues have β1‐6 linked N‐acetylglucosamine (GlcNAc) attached, forms the blood group I‐antigen, which is closely associated with various physiological and pathological processes including cancer progression. However, the underlying mechanisms remain unclear as many of the I‐antigen sequences are undefined and inaccessible. In this study, we developed a highly efficient orthogonal‐group‐controlled approach to access site‐selectively I‐branched poly‐LacNAc chains. The approach relies on three orthogonal protecting groups, each of them “caps” one internal Gal residue of poly‐LacNAc. These groups can be readily “decapped” by specific enzymes or chemical reduction to expose desired sites for GCNT2‐catalyzed I‐branching. This approach enabled the rapid preparation of a diverse library of 41 linear and branched poly‐LacNAc glycans from a single precursor. Glycan microarray analysis using these complex glycans revealed unique recognitions of I‐branches by lectins, anti‐I mAbs, and galectins. Surprisingly, oxidized forms of linear poly‐LacNAc strongly bound to several glycan‐binding proteins (GBPs). These findings help to bridge the gap in recognition of I‐branching and open new avenues for therapeutic development by targeting galectins.
Fluorescence imaging, a highly sensitive molecular imaging modality, is being increasingly integrated into clinical practice. Imaging within the second near-infrared biological window (NIR-II; 1,000 to 1,700 nm), also referred to as shortwave infrared, has received substantial attention because of its markedly reduced autofluorescence, deeper tissue penetration, and enhanced spatiotemporal resolution as compared to traditional near-infrared (NIR) imaging. Indocyanine green (ICG), a US Food and Drug Administration-approved NIR fluorophore, has long been used in clinical applications, including blood vessel angiography, vascular perfusion monitoring, and tumor detection. Recent advancements in NIR-II imaging technology have revitalized interest in ICG, revealing its extended tail fluorescence beyond 1,000 nm and reaffirming its potential as a clinically translatable NIR-II fluorophore for in vivo imaging and theranostic applications for diagnosing various diseases. This review emphasizes the notable advances in the use of ICG and its derivatives for NIR-II imaging and image-guided therapy from both fundamental and clinical perspectives. We also provide a concise conclusion and discuss the challenges and future opportunities with NIR-II imaging using clinically approved fluorophores.
Liver fibrosis is a progressive scarring process primarily caused by chronic inflammation and injury, often closely associated with viral hepatitis, alcoholic liver disease, metabolic dysfunction-associated steatotic liver disease (MASLD), drug-induced liver injury, and autoimmune liver disease (AILD). Currently, there are very few clinical antifibrotic drugs available, and effective targeted therapy is lacking. Recently, emerging antifibrotic drugs and immunomodulators have shown promising results in animal studies, and some have entered clinical research phases. This review aims to systematically review the molecular mechanisms underlying liver fibrosis, focusing on advancements in drug treatments for hepatic fibrosis. Furthermore, since liver fibrosis is a progression or endpoint of many diseases, it is crucial to address the etiological treatment and secondary prevention for liver fibrosis. We will also review the pharmacological treatments available for common hepatitis leading to liver fibrosis.
Hyaluronic acid (HA) is a natural and biocompatible polysaccharide that is able to interact with CD44 receptors to regulate inflammation, fibrosis, and tissue reconstruction. It is a suitable chemical scaffold for drug delivery that can be functionalized with pharmacophores and/or vectorizable groups. The derivatization of HA is achieved to varying extents by reacting 1-amino-1-deoxy-lactitol via the carboxyl group to form amide linkages, giving rise to the grafted polymer, HYLACH. This retains the broad properties of HA, even though, as in most HA-grafted polymers, the detailed conformational effects of such substitutions, while crucial in the design or optimization of drug delivery systems, remain unknown. Here, the conformation, size, secondary structure, hydrogen bond network, and hydration features of lactosylated HA derivatives were evaluated by using multiple independent molecular dynamics simulations. This revealed subtle but nevertheless significant changes in the HA scaffold, establishing the density of grafting as the key parameter determining its properties
Galectins are a family of galactoside‐binding proteins involved in various pathophysiological processes, which makes them attractive targets for drug discovery. The derivatization of d‐galactose at C3 and C1 positions has been shown to increase the affinity of synthetic galectin antagonists. In this study, two small libraries of d‐galactose derivatives have been designed and synthesized. The first series involved the development of novel aromatic 3‐azolyl‐3‐deoxy‐d‐galactopyranoses. The second series consisted of epimeric analogs of glyceryl β‐S‐d‐galactopyranosides, which were also derivatized. Binding‐affinity evaluations for galectin‐1 and galectin‐3 have revealed that galactose analogs from both series have potential for further optimization. Notably, a combination of modifications at the C3 position of the galactose ring and on the aglycone has led to the identification of promising galectin inhibitors, specifically the compounds 29R and 32S.
Galectins are β-galactosyl-binding lectins with key roles in early development, immune regulation, and infectious disease. Influenza A virus (IAV) infects the airway epithelia, and in severe cases may lead to bacterial superinfections and hypercytokinemia, and eventually, to acute respiratory distress syndrome (ARDS) through the breakdown of airway barriers. The detailed mechanisms involved, however, remain poorly understood. Our prior in vivo studies in a murine model system revealed that upon experimental IAV and pneumococcal primary and secondary challenges, respectively, galectin-1 and galectin-3 (Gal-3) are released into the airway and bind to the epithelium that has been desialylated by the viral neuraminidase, contributing to secondary bacterial infection and hypercytokinemia leading to the clinical decline and death of the animals. Here we report the results of in vitro studies that reveal the role of the extracellular Gal-3 in additional detrimental effects on the host by disrupting the integrity of the airway epithelial barrier. IAV infection of the human airway epithelia cell line A549 increased release of Gal-3 and its binding to the A549 desialylated cell surface, notably to the transmembrane signaling receptors CD147 and integrin-β1. Addition of recombinant Gal-3 to A549 monolayers resulted in enhanced expression and release of matrix metalloproteinases, leading to disruption of cell–cell tight junctions, and a significant increase in paracellular permeability. This study reveals a critical mechanism involving Gal-3 that may significantly contribute to the severity of IAV infections by promoting disruption of tight junctions and enhanced permeability of the airway epithelia, potentially leading to lung edema and ARDS.
Sugar mimics are valuable tools in medicinal chemistry, offering the potential to overcome the limitations of carbohydrate inhibitors, such as poor pharmacokinetics and non-selectivity. In our continued efforts to develop heterocyclic galectin-1 inhibitors, we report the synthesis and characterization of thiazole-linked coumarin piperazine hybrids (10a–10i) as Gal-1 inhibitors. The compounds were characterized using ¹H NMR, ¹³C NMR and HRMS. Among the synthesized molecules, four compounds demonstrated significant inhibitory activity, with more than 50% inhibition observed at a concentration of 20 μM in a Gal-1 enzyme assay. Fluorescence spectroscopy was further utilized to elucidate the binding constant for the synthesized compounds. 10g exhibited the highest affinity for Gal-1, with a binding constant (Ka) of 9.8 × 10⁴ M⁻¹. To elucidate the mode of binding, we performed extensive computational analyses with 10g, including 1.2 μs all-atom molecular dynamics simulations coupled with a robust machine learning tool. Our findings indicate that 10g binds to the carbohydrate binding site of Gal-1, with the coumarin moiety playing a key role in binding interactions. Additionally, our study underscores the limitations of relying solely on docking scores for conformational selection and highlights the critical importance of performing multiple MD replicas to gain accurate insights.
Numerous proteins in nature strictly require oligomerization for their full activity. Moreover, the function of natural and artificial proteins can me adjusted by altering their oligomeric state, leading to development of biotechnologically-relevant biomacromolecules. Oligomerization scaffolds from natural sources and designed de novo enable shuffling the oligomeric state and valency of biomacromolecules. In this report we probed the scaffolding potential of the thermostable phenylacetic acid degradation protein acyl-CoA from Thermus thermophilus (TtPaaI). We designed and successfully produced the fusion protein between TtPaaI (scaffold) and galectin-7, a multifunctional lectin implicated in human diseases (ligand) and demonstrated that TtPaaI can serve as a framework for functional multivalent display of ligands.
Liver fibrosis, mainly arising from chronic viral or metabolic liver diseases, is a significant global health concern. There is currently only one FDA‐approved drug (Resmetirom) in the market to combat liver fibrosis. Both galectin‐3 and epidermal growth factor receptor (EGFR) play important roles in liver fibrosis, while galectin‐3 may interact with EGFR. Galectin‐3 inhibitors, typically lactose or galactose derivatives may inhibit liver fibrosis. We hypothesized that targeting both galectin‐3 and EGFR may have better effect against liver fibrosis. Here, EGFR inhibitor erlotinib was used in a series of designed galectin‐3 inhibitors after hybridization with the pharmacophore structure in reported galectin‐3 inhibitors to impede hepatic stellate cells (HSCs) activation by a typical method of click chemistry. Bioactivity test results showed that compound 29 suppressed TGF‐β‐induced upregulation of fibrotic markers (α‐SMA, fibronectin‐1, and collagen I). The preferred compound 29 displayed better binding to galectin‐3 (KD=52.29 μM) and EGFR protein (KD=3.31 μM) by SPR assay. Further docking studies were performed to clarify the possible binding mode of compound 29 with galectin‐3 and EGFR. Taken together, these results suggested that compound 29 could be a potential dual galectin‐3 and EGFR inhibitor as leading compound for anti‐liver fibrosis new drug development.
In this paper, we applied an original chemical methodology in which gold salt (HAuCl4) interacts with the chemotherapeutic drug (bortezomib; i.e., BOR) by chelation and then stacked with dicarboxylic acid‐terminated polyethylene‐glycol (PEG‐diacide) as a biocompatible surfactant. The suggested chemical protocol is rapid (“one‐pot”) and reproducible, providing the formation of a hybrid‐nanovector named BOR IN PEG‐AuNPs. In order to prove a therapeutic approach, our hybrid‐nanovector (BOR IN PEG‐AuNPs) interacts with Galectin‐1 (Gal‐1) protein biomarker under specific concentrations. The efficient concentration range of this nanovector is obviously profiled by tumor microenvironment (TME) heterogeneity, optimizing cells access to the interaction region. Considering several influential factors related to spatial mapping and physical profile in all extracellular matrix (ECM), drive a change in neighborhood electrical potential configuration, leading the nanovector response with biomarkers transcriptions, hence, patterning TME leads to promote antitumor immunity in favor of tumor suppression. Each step of chemical synthesis and detection was monitored by spectroscopic techniques (Raman; UV‐Vis spectroscopies) and transmission electron microscopy (TEM). Our study demonstrated that hybrid‐nanoparticle system represents a key to further synergic chemotherapeutic and diagnostic tools for the treatment of cancer.
Objective:
To review the utility of galectin-3 (Gal-3) as a biomarker for postoperative adverse outcomes in patients undergoing cardiac surgery.
Method:
This review was conducted in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Electronic database search was conducted in October 2023. Studies that measured pre- and/or postoperative plasma Gal-3 levels in adult patients undergoing cardiac surgery were included. Primary outcomes included postoperative morbidity and mortality.
Results:
Out of 391 studies screened, eight studies met the inclusion criteria. Two of the three studies showed that preoperative plasma levels of Gal-3 were associated with acute kidney injury (AKI) after cardiac surgery. Two of the three studies reported a significant increase in preoperative Gal-3 levels in patients who developed postoperative atrial fibrillation (POAF). The addition of Gal-3 to the EuroSCORE II model was found to statistically improve the prediction of both AKI and POAF. Three of the five studies suggested that Gal-3 levels can predict postoperative mortality. Finally, one study suggested that lower preoperative Gal-3 levels was associated with a higher likelihood of achieving left ventricular reverse remodeling (LVRR) after surgery.
Conclusions:
Gal-3 may play a promising role in predicting adverse outcomes in patients undergoing cardiac surgery. The addition of Gal-3 to clinical risk prediction scores may improve their discriminatory power in this group of patients. Future studies are warranted to justify its incorporation into routine clinical practice.
Galectin-3 is a carbohydrate-binding protein central to regulating mechanisms of diseases such as fibrosis, cancer, metabolic, inflammatory, and heart disease. We recently found a high affinity (nM) thiodigalactoside GB0139 which currently is in clinical development (PhIIb) as an inhaled treatment of idiopathic pulmonary fibrosis. To enable treatment of systemically galectin-3 driven disease, we here present the first series of selective galectin-3 inhibitors combining high affinity (nM) with oral bioavailability. This was achieved by optimizing galectin-3 specificity and physical chemical parameters for a series of disubstituted monogalactosides. Further characterization showed that this class of compounds reduced profibrotic gene expression in liver myofibroblasts and displayed antifibrotic activity in CCl4-induced liver fibrosis and bleomycin-induced lung fibrosis mouse models. On the basis of the overall pharmacokinetic, pharmacodynamic, and safety profile, GB1211 was selected as the clinical candidate and is currently in phase IIa clinical trials as a potential therapy for liver cirrhosis and cancer.
Cancer cells can evade immune responses by exploiting inhibitory immune checkpoints. Immune checkpoint inhibitor (ICI) therapies based on anti-CTLA-4 and anti-PD-1/PD-L1 antibodies have been extensively explored over the recent years to unleash otherwise compromised anti-cancer immune responses. However, it is also well established that immune suppression is a multifactorial process involving an intricate crosstalk between cancer cells and the immune systems. The cancer glycome is emerging as a relevant source of immune checkpoints governing immunosuppressive behaviour in immune cells, paving an avenue for novel immunotherapeutic options. This review addresses the current state-of-the-art concerning the role played by glycans controlling innate and adaptive immune responses, while shedding light on available experimental models for glycoimmunology. We also emphasize the tremendous progress observed in the development of humanized models for immunology, the paramount contribution of advances in high-throughput single-cell analysis in this context, and the importance of including predictive machine learning algorithms in translational research. This may constitute an important roadmap for glycoimmunology, supporting careful adoption of models foreseeing clinical translation of fundamental glycobiology knowledge towards next generation immunotherapies.
Pathological vascular remodeling is the underlying cause of atherosclerosis and abdominal aortic aneurysm (AAA). Here, we analyzed the role of galectin-1 (Gal-1), a β-galactoside-binding protein, as a therapeutic target for atherosclerosis and AAA. Mice lacking Gal-1 (Lgals1-/-) developed severe atherosclerosis induced by pAAV/D377Y-mPCSK9 adenovirus and displayed higher lipid levels and lower expression of contractile markers of vascular smooth muscle cells (VSMCs) in plaques than wild-type mice. Proteomic analysis of Lgals1-/- aortas showed changes in markers of VSMC phenotypic switch and altered composition of mitochondrial proteins. Mechanistically, Gal-1 silencing resulted in increased foam cell formation and mitochondrial dysfunction in VSMCs, while treatment with recombinant Gal-1 (rGal-1) prevented these effects. Furthermore, rGal-1 treatment attenuated atherosclerosis and elastase-induced AAA, leading to higher contractile VSMCs in aortic tissues. Gal-1 expression decreased in human atheroma and AAA compared to control tissue. Thus, Gal-1-driven circuits emerge as potential therapeutic strategies in atherosclerosis and AAA.
While adaptive immunity recognizes a nearly infinite range of antigenic determinants, immune tolerance renders adaptive immunity vulnerable to microbes decorated in self-like antigens. Recent studies suggest that sugar-binding proteins galectin-4 and galectin-8 bind microbes expressing blood group antigens. However, the binding profile and potential antimicrobial activity of other galectins, particularly galectin-9 (Gal-9), has remained incompletely defined. Here we demonstrate that while Gal-9 possesses strong binding preference for ABO(H) blood group antigens, each domain exhibits distinct binding patterns, with the C-terminal domain (Gal-9C) exhibiting higher binding to blood group B than the N-terminal domain (Gal-9N). Despite this binding preference, while Gal-9 readily killed blood group B-positive Escherichia coli, Gal-9N displayed higher killing activity against this microbe than Gal-9C. Utilization of microarrays populated with blood group O antigens from a diverse array of microbes revealed that while Gal-9 can bind various microbial glycans, Gal-9N and Gal-9C displayed distinct and overlapping binding preferences. Flow cytometric examination of intact microbes corroborated the microbial glycan microarray findings, demonstrating that Gal-9, Gal-9N, and Gal-9C also possess the capacity to recognize distinct strains of Providencia alcalifaciens and Klebsiella pneumoniae that express mammalian blood group-like antigens while failing to bind related strains that do not express mammalian-like glycans. In each case of microbial binding, Gal-9, Gal-9N and Gal-9C induced microbial death. In contrast, while Gal-9, Gal-9N, and Gal-9C engaged red blood cells, each failed to induce hemolysis. These data suggest that Gal-9 recognition of distinct microbial strains may provide antimicrobial activity against molecular mimicry.
Galectin-1 (GAL1), a β-galactoside-binding protein abundantly expressed in the tumor microenvironment, has emerged as a key mechanism of chemoresistance developed by different tumors. Although increased expression of GAL1 is a hallmark of hepatocellular carcinoma (HCC) progression, aggressiveness and metastasis, limited information is available on the role of this endogenous lectin in HCC resistance to chemotherapy. Moreover, the precise mechanisms underlying this effect are uncertain. HCC has evolved different mechanisms of resistance to chemotherapy including those involving the P-glycoprotein (P-gp), an ATP-dependent drug efflux pump, which controls intracellular drug concentration. Here, we investigated the molecular mechanism underlying GAL1-mediated chemoresistance in HCC cells, particularly the involvement of P-gp in this effect. Our results show that GAL1 protected HepG2 cells from doxorubicin (DOX)- and sorafenib-induced cell death in vitro. Accordingly, GAL1-overexpressing HepG2 cells generated DOX-resistant tumors in vivo. High expression of GAL1 in HepG2 cells reduced intracellular accumulation of DOX likely by increasing P-gp protein expression rather than altering its membrane localization. GAL1-mediated increase of P-gp expression involved activation of the phosphatidylinositol-3 kinase (PI3K) signaling pathway. Moreover, ‘loss-of-function’ experiments revealed that P-gp mediates GAL1-driven resistance to DOX, but not to sorafenib, in HepG2 cells. Conversely, in PLC/PRF/5 cells, P-gp protein expression was undetectable and GAL1 did not control resistance to DOX or sorafenib, supporting the critical role of P-gp in mediating GAL1 effects. Collectively, our findings suggest that GAL1 confers chemoresistance in HCC through mechanisms involving modulation of P-gp, thus emphasizing the role of this lectin as a potential therapeutic target in HCC.
Galectin-1 (Gal1) is a glycan-binding protein that promotes tumor progression by several distinct mechanisms. Through direct binding to vascular endothelial growth factor (VEGF)-receptor 2, Gal1 is able to induce VEGF-like signaling, which contributes to tumor angiogenesis. Furthermore, several studies have demonstrated an immunosuppressive function of Gal1 through effects on both effector and regulatory T cells. Elevated Gal1 expression and secretion have been shown in many tumor types, and high Gal1 serum levels have been connected to poor prognosis in cancer patients. These findings suggest that therapeutic strategies directed against Gal1 would enable simultaneous targeting of angiogenesis, immune evasion and metastasis. In the current study, we have analyzed the potential of Gal1 as a cancer vaccine target. We show that it is possible to generate high anti-Gal1 antibody levels in mice immunized with a recombinant vaccine protein consisting of bacterial sequences fused to Gal1. Growth of Gal1 expressing melanomas was significantly impaired in the immunized mice compared to the control group. This was associated with improved perfusion of the tumor vasculature, as well as increased infiltration of macrophages and cytotoxic T cells (CTLs). The level of granzyme B, mainly originating from CTLs in our model, was significantly elevated in Gal1 vaccinated mice and correlated with a decrease in tumor burden. We conclude that vaccination against Gal1 is a promising pro-immunogenic approach for cancer therapy that could potentially enhance the effect of other immunotherapeutic strategies due to its ability to promote CTL influx in tumors.
Optimal therapy of biochemically relapsed prostate cancer (BRPC) after local treatment is elusive. An established modified citrus pectin (PectaSol®, P-MCP), a dietary polysaccharide, is an established antagonist of galectin-3, a carbohydrate-binding protein involved in cancer pathogenesis. Based on PSA dynamics, we report on the safety and the primary outcome analysis of a prospective phase II study of P-MCP in non-metastatic BRPC based. Sixty patients were enrolled, and one patient withdrew after a month. Patients (n = 59) were given P-MCP, 4.8 grams X 3/day, for six months. The primary endpoint was the rate without PSA progression and improved PSA doubling time (PSADT). Secondary endpoints were the rate without radiologic progression and toxicity. Patients that did not progress by PSA and radiologically at six months continued for an additional twelve months. After six months, 78% (n = 46) responded to therapy, with a decreased/stable PSA in 58% (n = 34), or improvement of PSADT in 75% (n = 44), and with negative scans, and entered the second twelve months treatment phase. Median PSADT improved significantly (p = 0.003). Disease progression during the first 6 months was noted in only 22% (n = 13), with PSA progression in 17% (n = 10), and PSA and radiologic progression in 5% (n = 3). No patients developed grade 3 or 4 toxicity.
While adaptive immunity enables the recognition of a wide range of microbial antigens, immunological tolerance limits reactively toward self to reduce autoimmunity. Some bacteria decorate themselves with self-like antigens as a form of molecular mimicry to limit recognition by adaptive immunity. Recent studies suggest that galectin-4 (Gal-4) and galectin-8 (Gal-8) may provide a unique form of innate immunity against molecular mimicry by specifically targeting microbes that decorate themselves in self-like antigens. However, the binding specificity and antimicrobial activity of many human galectins remain incompletely explored. In this study, we defined the binding specificity of galectin-3 (Gal-3), the first galectin shown to engage microbial glycans. Gal-3 exhibited high binding toward mammalian blood group A, B, and αGal antigens in a glycan microarray format. In the absence of the N-terminal domain, the C-terminal domain of Gal-3 (Gal-3C) alone exhibited a similar overall binding pattern, but failed to display the same level of binding for glycans over a range of concentrations. Similar to the recognition of mammalian glycans, Gal-3 and Gal-3C also specifically engaged distinct microbial glycans isolated and printed in a microarray format, with Gal-3 exhibiting higher binding at lower concentrations toward microbial glycans than Gal-3C. Importantly, Gal-3 and Gal-3C interactions on the microbial microarray accurately predicted actual interactions toward intact microbes, with Gal-3 and Gal-3C displaying carbohydrate-dependent binding toward distinct strains of Providentia alcalifaciens and Klebsiella pneumoniae that express mammalian-like antigens, while failing to recognize similar strains that express unrelated antigens. While both Gal-3 and Gal-3C recognized specific strains of P. alcalifaciens and K. pneumoniae, only Gal-3 was able to exhibit antimicrobial activity even when evaluated at higher concentrations. These results demonstrate that while Gal-3 and Gal-3C specifically engage distinct mammalian and microbial glycans, Gal-3C alone does not possess antimicrobial activity.
Although pharmacological stimulation of TLRs has anti-tumor effects, it has not been determined whether endogenous stimulation of TLRs can lead to tumor rejection. Herein, we demonstrate the existence of an innate anti-glioma NK-mediated circuit initiated by glioma-released miR-1983 within exosomes, and which is under the regulation of galectin-1 (Gal-1). We demonstrate that miR-1983 is an endogenous TLR7 ligand that activates TLR7 in pDCs and cDCs through a 5ʹ-UGUUU-3ʹ motif at its 3ʹ end. TLR7 activation and downstream signaling through MyD88-IRF5/IRF7 stimulates secretion of IFN-β. IFN-β then stimulates NK cells resulting in the eradication of gliomas. We propose that successful immunotherapy for glioma could exploit this endogenous innate immune circuit to activate TLR7 signaling and stimulate powerful anti-glioma NK activity, at least 10–14 days before the activation of anti-tumor adaptive immunity.
Diverse immunoregulatory circuits operate to preserve intestinal homeostasis and prevent inflammation. Galectin-1 (Gal1), a β-galactoside–binding protein, promotes homeostasis by reprogramming innate and adaptive immunity. Here, we identify a glycosylation-dependent “on-off” circuit driven by Gal1 and its glycosylated ligands that controls intestinal immunopathology by targeting activated CD8 ⁺ T cells and shaping the cytokine profile. In patients with inflammatory bowel disease (IBD), augmented Gal1 was associated with dysregulated expression of core 2 β6- N -acetylglucosaminyltransferase 1 ( C2GNT1 ) and α(2,6)-sialyltransferase 1 ( ST6GAL1 ), glycosyltransferases responsible for creating or masking Gal1 ligands. Mice lacking Gal1 exhibited exacerbated colitis and augmented mucosal CD8 ⁺ T cell activation in response to 2,4,6-trinitrobenzenesulfonic acid; this phenotype was partially ameliorated by treatment with recombinant Gal1. While C2gnt1 −/− mice exhibited aggravated colitis, St6gal1 −/− mice showed attenuated inflammation. These effects were associated with intrinsic T cell glycosylation. Thus, Gal1 and its glycosylated ligands act to preserve intestinal homeostasis by recalibrating T cell immunity.
Tim‐3 is a negative immunoregulator in anti‐tumor response, but its mechanism in chronic lymphocytic leukemia (CLL) is not yet clear. The aim of this study was to understand the role of Galectin‐9/Tim‐3 signaling pathway in the regulation of CD4⁺ T cell subsets in CLL patients. Flow cytometry results showed that the number of Treg cells obviously increased, and there was a significant Treg/Th17 imbalance in CLL patients. In addition, Tim‐3 overexpressed on the surface of Th1 and Treg cells in CLL patients. The levels of Galectin‐9 and IL‐10 were significantly elevated in patients of CLL, especially in stages of Binet B, and C. However, IFN‐γ decreased. Moreover, Galectin‐9 in CLL patients was positively correlated with the number of Tim‐3⁺ Treg cells and the level of IL‐10. Interestingly, when the Tim‐3/Galectin‐9 pathway was blocked in vitro, the level of IL‐10 in the culture supernatant of CD4⁺ T was significantly reduced, while the levels of IFN‐γ and TNF‐α were increased. After co‐culture with activated Th1 cells, the apoptosis of CLL cells was significantly increased, and this effect was reversed after treatment with Tim‐3⁺ Tregs. In summary, Galectin‐9/Tim‐3 are elevated in CLL and associated with disease progression. By the negative regulation of CD4⁺ T cells, activated Galectin‐9/Tim‐3 suppresses Th1 effector function and also promotes Treg to be involved in immune escape of CLL. This pathway might become the potential target of immunotherapy in CLL patients.
Although the overall survival rate of papillary or follicular thyroid cancers is good, anaplastic carcinomas and radio iodine refractory cancers remain a significant therapeutic challenge. Galectin-1 (Gal-1) is overexpressed in tumor cells and tumor-associated endothelial cells, and is broadly implicated in angiogenesis, cancer cell motility and invasion, and immune system escape. Our team has previously demonstrated a higher serum level of Gal-1 in patients with differentiated thyroid cancers versus healthy patients, and explored, by a knockdown strategy, the effect of Gal-1 silencing on cell proliferation and invasion in vitro, and on tumor and metastasis development in vivo. OTX008 is a calixarene derivative designed to bind the Gal-1 amphipathic β-sheet conformation and has previously demonstrated anti-proliferative and anti-invasive properties in several cancer cell lines including colon, breast, head and neck, and prostate cancer lines. In the current work, the impacts of OTX008 were evaluated in six thyroid cancer cell lines, and significant inhibitions of proliferation, migration, and invasion were observed in all lines expressing high Gal-1 levels. In addition, the signaling pathways affected by this drug were examined using RPPA (reverse phase protein array) and phosphoprotein expression assays, and opposite regulation of eNos, PYK2, and HSP27 by OTX008 was detected by comparing the two anaplastic lines 8505c and CAL 62. Finally, the sensitive 8505c line was xenografted in nude mice, and 3 weeks of OTX008 treatment (5 mg/kg/day) demonstrated a significant reduction in tumor and lung metastasize sizes without side effects. Overall, OXT008 showed significant anti-cancer effects both in vitro and in vivo in thyroid cancer lines expressing Gal-1, supporting further investigation of the molecular mechanisms of the drug and future clinical trials in patients with anaplastic thyroid cancer.
Galectins are animal lectins that recognize carbohydrates and play important roles in maintaining cellular homeostasis. Recent studies have indicated that under a variety of challenges, intracellular galectins bind to host glycans displayed on damaged endocytic vesicles and accumulate around these damaged organelles. Accumulated galectins then engage cellular proteins and subsequently control cellular responses, such as autophagy. In this review, we have summarized the stimuli that lead to the accumulation of galectins, the molecular mechanisms of galectin accumulation, and galectin-mediated cellular responses, and elaborate on the differential regulatory effects among galectins.
Treatment with an agonist anti-OX40 antibody (aOX40) boosts anti-tumor immunity by providing costimulation and driving effector T cell responses. However, tumor-induced immune suppression contributes significantly to poor response rates to aOX40 therapy, thus combining aOX40 with other agents that relieve tumor-mediated immune suppression may significantly improve outcomes. Once such target is galectin-3 (Gal-3), which drives tumor-induced immunosuppression by increasing macrophage infiltration and M2 polarization, restricting TCR signaling, and inducing T cell apoptosis. A wide-variety of tumors also upregulate Gal-3, which is associated with poor prognosis. Tumor-bearing (MCA-205 sarcoma, 4T1 mammary carcinoma, TRAMP-C1 prostate adenocarcinoma) mice were treated with a Gal-3 inhibitor (belapectin; GR-MD-02), aOX40, or combination therapy and the extent of tumor growth was determined. The phenotype and function of tumor-infiltrating lymphocytes was determined by flow cytometry, multiplex cytokine assay, and multiplex immunohistochemistry. Gal-3 inhibition synergized with aOX40 to promote tumor regression and increase survival. Specifically, aOX40/belapectin therapy significantly improved survival of tumor-bearing mice through a CD8⁺ T cell-dependent mechanism. Combination aOX40/belapectin therapy enhanced CD8⁺ T cell density within the tumor and reduced the frequency and proliferation of regulatory Foxp3⁺CD4⁺ T cells. Further, aOX40/belapectin therapy significantly reduced monocytic MDSC (M-MDSCs) and MHC-IIhi macrophage populations, both of which displayed reduced arginase 1 and increased iNOS. Combination aOX40/belapectin therapy alleviated M-MDSC-specific functional suppression compared to M-MDSCs isolated from untreated tumors. Our data suggests that Gal-3 inhibition plus aOX40 therapy reduces M-MDSC-meditated immune suppression thereby increasing CD8⁺ T cell recruitment leading to increased tumor regression and survival.
Multimodal single-cell RNA sequencing enables the precise mapping of transcriptional and phenotypic features
of cellular differentiation states but does not allow for simultaneous integration of critical posttranslational mod-
ification data. Here, we describe SUrface-protein Glycan And RNA-seq (SUGAR-seq), a method that enables detec-
tion and analysis of N-linked glycosylation, extracellular epitopes, and the transcriptome at the single-cell level.
Integrated SUGAR-seq and glycoproteome analysis identified tumor-infiltrating T cells with unique surface glycan
properties that report their epigenetic and functional state.
The lectin, galectin-3 (Gal3), has been implicated in a variety of inflammatory and oncogenic processes, including tumor growth, invasion, and metastasis. The interactions of Gal3 and MUC16 represent a potential targetable pathway for the treatment of MUC16-expressing malignancies. We found that the silencing of Gal3 in MUC16-expressing breast and ovarian cancer cells in vitro inhibited tumor cell invasion and led to attenuated tumor growth in murine models. We therefore developed an inhibitory murine monoclonal anti–Gal3 carbohydrate-binding domain antibody, 14D11, which bound human and mouse Gal3 but did not bind human Galectins-1, -7, -8 or -9. Competition studies and a docking model suggest that the 14D11 antibody competes with lactose for the carbohydrate binding pocket of Gal3. In MUC16-expressing cancer cells, 14D11 treatment blocked AKT and ERK1/2 phosphorylation, and led to inhibition of cancer cell Matrigel invasion. Finally, in experimental animal tumor models, 14D11 treatment led to prolongation of overall survival in animals bearing flank tumors, and retarded lung specific metastatic growth by MUC16 expressing breast cancer cells. Our results provide evidence that antibody based Gal3 blockade may be a viable therapeutic strategy in patients with MUC16-expressing tumors, supporting further development of human blocking antibodies against Gal3 as potential cancer therapeutics.
The two T cell inhibitory receptors PD-1 and TIM-3 are co-expressed during exhausted T cell differentiation, and recent evidence suggests that their crosstalk regulates T cell exhaustion and immunotherapy efficacy; however, the molecular mechanism is unclear. Here we show that PD-1 contributes to the persistence of PD-1 + TIM-3 + T cells by binding to the TIM-3 ligand galectin-9 (Gal-9) and attenuates Gal-9/TIM-3-induced cell death. Anti-Gal-9 therapy selectively expands intratumoral TIM-3 + cytotoxic CD8 T cells and immunosuppressive regulatory T cells (T reg cells). The combination of anti-Gal-9 and an agonistic antibody to the co-stimulatory receptor GITR (glucocorticoid-induced tumor necrosis factor receptor-related protein) that depletes T reg cells induces synergistic antitumor activity. Gal-9 expression and secretion are promoted by interferon β and γ, and high Gal-9 expression correlates with poor prognosis in multiple human cancers. Our work uncovers a function for PD-1 in exhausted T cell survival and suggests Gal-9 as a promising target for immunotherapy.
We investigated the effect of galectin-3 (Gal-3) inhibition with modified citrus pectin on markers of collagen metabolism in a proof-of-concept randomized placebo-controlled trial of participants with elevated Gal-3 levels and hypertension. Although higher Gal-3 levels were associated with female sex, diabetes, and reduced glomerular filtration rate in cross-sectional analyses, treatment with modified citrus pectin did not change collagen markers. The effect of Gal-3 inhibition among individuals with heart failure warrants further investigation.
Inflammatory caspase sensing of cytosolic lipopolysaccharide (LPS) triggers pyroptosis and the concurrent release of damage-associated molecular patterns (DAMPs). Collectively, DAMPs are key determinants that shape the aftermath of inflammatory cell death. However, the identity and function of the individual DAMPs released are poorly defined. Our proteomics study revealed that cytosolic LPS sensing triggered the release of galectin-1, a β-galactoside-binding lectin. Galectin-1 release is a common feature of inflammatory cell death, including necroptosis. In vivo studies using galectin-1-deficient mice, recombinant galectin-1 and galectin-1-neutralizing antibody showed that galectin-1 promotes inflammation and plays a detrimental role in LPS-induced lethality. Mechanistically, galectin-1 inhibition of CD45 (Ptprc) underlies its unfavorable role in endotoxin shock. Finally, we found increased galectin-1 in sera from human patients with sepsis. Overall, we uncovered galectin-1 as a bona fide DAMP released as a consequence of cytosolic LPS sensing, identifying a new outcome of inflammatory cell death.
Background
We have previously reported that the upregulation of galectin-9 (Gal-9) on CD4 ⁺ and CD8 ⁺ T cells in HIV patients was associated with impaired T cell effector functions. Gal-9 is a ligand for T cell immunoglobulin and mucin domain-3, and its expression on T cells in cancer has not been investigated. Therefore, we aimed to investigate the expression level and effects of Gal-9 on T cell functions in patients with virus-associated solid tumors (VASTs).
Methods
40 patients with VASTs through a non-randomized and biomarker-driven phase II LATENT trial were investigated. Peripheral blood mononuclear cells and tumor biopsies were obtained and subjected to immunophenotyping. In this trial, the effects of oral valproate and avelumab (anti-PD-L1) was investigated in regards to the expression of Gal-9 on T cells.
Results
We report the upregulation of Gal-9 expression by peripheral and tumor-infiltrating CD4 ⁺ and CD8 ⁺ T lymphocytes in patients with VASTs. Our results indicate that Gal-9 expression is associated with dysfunctional T cell effector functions in the periphery and tumor microenvironment (TME). Coexpression of Gal-9 with PD-1 or T cell immunoglobulin and ITIM domain (TIGIT) exhibited a synergistic inhibitory effect and enhanced an exhausted T cell phenotype. Besides, responding patients to treatment had lower Gal-9 mRNA expression in the TME. Translocation of Gal-9 from the cytosol to the cell membrane of T cells following stimulation suggests persistent T cell receptor (TCR) stimulation as a potential contributing factor in Gal-9 upregulation in patients with VASTs. Moreover, partial colocalization of Gal-9 with CD3 on T cells likely impacts the initiation of signal transduction via TCR as shown by the upregulation of ZAP70 in Gal-9+ T cells. Also, we found an expansion of Gal-9+ but not TIGIT+ NK cells in patients with VASTs; however, dichotomous to TIGIT+ NK cells, Gal-9+ NK cells exhibited impaired cytotoxic molecules but higher Interferon gamma (IFN-γ) expression.
Conclusion
Our data indicate that higher Gal-9-expressing CD8 ⁺ T cells were associated with poor prognosis following immunotherapy with anti-Programmed death-ligand 1 (PD-L1) (avelumab) in our patients’ cohort. Therefore, for the very first time to our knowledge, we report Gal-9 as a novel marker of T cell exhaustion and the potential target of immunotherapy in patients with VASTs.
Calix[4]arene PTX008 is an angiostatic agent that inhibits tumor growth in mice by binding to galectin‐1, a β‐galactoside‐binding lectin. To assess the affinity profile of PTX008 for galectins, we used ¹⁵N,¹H HSQC NMR spectroscopy to show that PTX008 also binds to galectin‐3 (Gal‐3), albeit more weakly. We identified the contact site for PTX008 on the F‐face of the Gal‐3 carbohydrate recognition domain. STD NMR revealed that the hydrophobic phenyl ring crown of the calixarene is the binding epitope. With this information, we performed molecular modeling of the complex to assist in improving the rather low affinity of PTX008 for Gal‐3. By removing the N‐dimethyl alkyl chain amide groups, we produced PTX013 whose reduced alkyl chain length and polar character led to an approximately eightfold stronger binding than PTX008. PTX013 also binds Gal‐1 more strongly than PTX008, whereas neither interacts strongly, if at all, with Gal‐7. In addition, PTX013, like PTX008, is an allosteric inhibitor of galectin binding to the canonical ligand lactose. This study broadens the scope for galectin targeting by calixarene‐based compounds and opens the perspective for selective galectin blocking.
Galectin-3 is a beta-galactoside-binding mammalian lectin and part of the 15 member galectin family that are evolutionarily highly conserved. It is the only chimeric protein with a C‐terminal carbohydrate recognition domain (CRD) linked to a proline, glycine, and tyrosine rich additional N‐terminal domain. Galectin-3 binds several cell surface glycoproteins via its CRD domain as well as undergoing oligomerization, via binding at the N-terminal or the CRD, resulting in the formation of a galectin‐3 lattice on the cell surface. The galectin-3 lattice has been regarded as being a crucial mechanism whereby extracellular galectin-3 modulates cellular signalling by prolonging retention time or retarding lateral movement of cell surface receptors in the plasma membrane. As such galectin-3 can regulate various cellular functions such as diffusion, compartmentalization and endocytosis of plasma membrane glycoproteins and glycolipids and the functionality of membrane receptors. In multiple models of organ fibrosis, it has been demonstrated that galectin-3 is potently pro-fibrotic and modulates the activity of fibroblasts and macrophages in chronically inflamed organs. Increased galectin-3 expression also activates myofibroblasts resulting in scar formation and may therefore impact common fibrotic pathways leading to fibrosis in multiple organs. Over the last decade there has been a marked increase in the scientific literature investigating galectin-3 in a range of fibrotic diseases as well as the clinical development of new galectin-3 inhibitors. In this review we will examine the role of galectin‐3 in fibrosis, the therapeutic strategies for inhibiting galectin-3 in fibrotic disease and the clinical landscape to date.
Background: Prostate cancer (PCa) is a major health problem worldwide. Taxol derivatives–based chemotherapies or immunotherapies are usually proposed depending on the symptomatic status of the patient. In the case of immunotherapy, tumors develop robust immune escape mechanisms that abolish any protective response, and to date why prostate cancer is one of the most resistant diseases remains unresolved.
Methods: By using a combination of clinical data to study the transcriptome of metastasis samples from castration-refractory patients, and state of the art cellular and molecular biology assays in samples from tumor-bearing mice that have been submitted to surgical resection of the tumor before receiving a vaccination, we answered several essential questions in the field of immunotherapy for prostate cancer. We also used two different methods to inhibit the expression of galectin-3 (Gal-3) in tumor cells: a stable RNA interference method to control the expression of this galectin efficiently only in tumor cells, and low and non-cytotoxic doses of Docetaxel to easily transfer our findings to clinical settings.
Results: Herein, we show for the first time that Galectin-3 (Gal-3) expressed by prostate tumor cells is the main immune checkpoint responsible for the failure of vaccine-based immunotherapy. Our results show that low and non-cytotoxic doses of docetaxel lead to the inhibition of Gal-3 expression in PCa cells as well as in clinical samples of mCRPC patients promoting a Th1 response. We thus optimized a prostate cancer animal model that undergoes surgical resection of the tumor to mimic prostatectomy usually performed in patients. Importantly, using Gal-3-knocked down-PCa cells or low and non-cytotoxic doses of taxane before vaccination, we were able to highly control tumor recurrence through a direct impact on the proliferation and infiltration of CD8+ cytotoxic T.
Conclusions: Thus, Gal-3 expression by PCa cells is a crucial inhibitor for the success of immunotherapy, and low doses of docetaxel with non-cytotoxic effect on leukocyte survival could be used before immunotherapy for all PCa patients to reduce the expression of this critical negative immune checkpoint, pre-conditioning the tumor-microenvironment to activate an anti-tumor immune response and promote tumor-free outcome.
Galectin-9 (Gal-9) is known to enhance the expansion of myeloid-derived suppressor cells (MDSCs) in murine models. Its contribution to the expansion of MDSCs in human malignancies remain to be investigated. We here report that Gal-9 expression in nasopharyngeal carcinoma (NPC) cells enhances the generation of MDSCs (CD33+CD11b+HLA-DR−) from CD33+ bystander cells. The underlying mechanisms involve both the intracellular and secreted Gal-9. Inside carcinoma cells, Gal-9 up-regulates the expression of a variety of pro-inflammatory cytokines which are critical for MDSC differentiation, including IL-1β and IL-6. This effect is mediated by accelerated STING protein degradation resulting from direct interaction of the Gal-9 carbohydrate recognition domain 1 with the STING C-terminus and subsequent enhancement of the E3 ubiquitin ligase TRIM29-mediated K48-linked ubiquitination of STING. Moreover, we showed that extracellular Gal-9 secreted by carcinoma cells can enter the myeloid cells and trigger the same signaling cascade. Consistently, high concentrations of tumor and plasma Gal-9 are associated with shortened survival of NPC patients. Our findings unearth that Gal-9 induces myeloid lineage-mediated immunosuppression in tumor microenvironments by suppressing STING signaling.
The synthesis of tailored bioactive carbohydrates usually comprises challenging (de)protection steps, which lowers synthetic yields and increases time demands. We present here a regioselective single‐step introduction of benzylic substituents at 3‐hydroxy groups of β‐d‐galactopyranosyl‐(1→1)‐thio‐β‐d‐galactopyranoside (TDG) employing dibutyltin oxide in good yields. These glycomimetics act as inhibitors of galectins—human lectins, which are biomedically attractive targets for therapeutic inhibition in, for example, cancerogenesis. The affinity of the prepared glycomimetics to galectin‐1 and galectin‐3 was studied in enzyme‐linked immunosorbent (ELISA)‐type assays and their potential to inhibit galectin binding on the cell surface was shown. We used our original in vivo biotinylated galectin constructs for easy detection by flow cytometry. The results of the biological experiments were compared with data from molecular modeling with both galectins. The present work reveals a facile and elegant synthetic route for the preparation of TDG‐derived glycomimetics that exhibit differing selectivity and affinity to galectins depending on the choice of 3‐O‐substitution.
We introduce an engineered nanobody whose affinity to green fluorescent protein (GFP) can be switched on and off with small molecules. By controlling the cellular localization of GFP fusion proteins, the engineered nanobody allows interrogation of their roles in basic biological processes, an approach that should be applicable to numerous previously described GFP fusions. We also outline how the binding affinities of other nanobodies can be controlled by small molecules. Engineered nanobody allows reversible control of activity in cells through the binding of small molecules.
Background:
Galectin-9 is a β-galactoside-binding protein with two carbohydrate recognition domains. Recent studies have revealed that galectin-9 regulates cellular biological reactions and plays a pivotal role in fibrosis. The aim of this study was to determine the role of galectin-9 in the pathogenesis of bleomycin-induced systemic sclerosis (SSc).
Methods:
Human galectin-9 levels in the serum of patients with SSc and mouse sera galectin-9 levels were measured by a Bio-Plex immunoassay and enzyme-linked immunosorbent assay. Lung fibrosis was induced using bleomycin in galectin-9 wild-type and knockout mice. The effects of galectin-9 on the fibrosis markers and signaling molecules in the mouse lung tissues and primary lung fibroblast cells were assessed with western blotting and quantitative polymerase chain reaction.
Results:
Galectin-9 levels in the serum were significantly higher (9-fold) in patients compared to those of healthy individuals. Galectin-9 deficiency in mice prominently ameliorated epithelial proliferation, collagen I accumulation, and α-smooth muscle actin expression. In addition, the galectin-9 knockout mice showed reduced protein expression levels of fibrosis markers such as Smad2/3, connective tissue growth factor, and endothelin-1. Differences between the wild-type and knockout groups were also observed in the AKT, mitogen-activated protein kinase, and c-Jun N-terminal kinase signaling pathways. Galectin-9 deficiency decreased the signal activation induced by transforming growth factor-beta in mouse primary fibroblasts, which plays a critical role in fibroblast activation and aberrant catabolism of the extracellular matrix.
Conclusions:
Our findings suggest that lack of galectin-9 protects against bleomycin-induced SSc. Moreover, galectin-9 might be involved in regulating the progression of fibrosis in multiple pathways.
Hanahan and Weinberg have proposed 10 organizing principles that enable growth and metastatic dissemination of cancer cells. These distinctive and complementary capabilities, defined as the "hallmarks of cancer," include the ability of tumor cells and their microenvironment to sustain proliferative signaling, evade growth suppressors, resist cell death, promote replicative immortality, induce angiogenesis, support invasion and metastasis, reprogram energy metabolism, induce genomic instability and inflammation, and trigger evasion of immune responses. These common features are hierarchically regulated through different mechanisms, including those involving glycosylation-dependent programs that influence the biological and clinical impact of each hallmark. Galectins, an evolutionarily conserved family of glycan-binding proteins, have broad influence in tumor progression by rewiring intracellular and extracellular circuits either in cancer or stromal cells, including immune cells, endothelial cells, and fibroblasts. In this review, we dissect the role of galectins in shaping cellular circuitries governing each hallmark of tumors, illustrating relevant examples and highlighting novel opportunities for treating human cancer.
Background & aims:
Increased levels of galectin 3 have been associated with nonalcoholic steatohepatitis (NASH) and contributes to toxin-induced liver fibrosis in mice. GR-MD-02 (belapectin) is an inhibitor of galectin 3 that reduces liver fibrosis and portal hypertension in rats and was safe and well tolerated in phase 1 studies. We performed a phase 2b, randomized trial of the safety and efficacy of GR-MD-02 in patients with NASH, cirrhosis, and portal hypertension.
Methods:
Patients with NASH, cirrhosis, and portal hypertension (hepatic venous pressure gradient [HVPG] ≥6 mm Hg) from 36 centers were randomly assigned, in a double-blind manner, to groups that received biweekly infusions of belapectin 2 mg/kg (n=54), 8 mg/kg (n=54), or placebo (n=54) for 52 weeks. The primary endpoint was change in HVPG (-28) at the end of the 52 week period compared with baseline. Secondary endpoints included changes in liver histology and development of liver-related outcomes.
Results:
We found no significant difference in ΔHVPG between the 2 mg/kg belapectin group and placebo group (-0.28 mmHG vs 0.10 mmHG, P=1.0) or between the 8 mg/kg belapectin and placebo group (-0.25 mmHG vs 0.10 mmHG, P=1.0). Belapectin had no significant effect on fibrosis or nonalcoholic fatty liver disease activity score, and liver-related outcomes did not differ significantly among groups. In an analysis of a subgroup of patients without esophageal varices at baseline (n=81), 2 mg/kg belapectin was associated with a reduction in HVPG at 52 weeks compared with baseline (P=.02) and reduced development of new varices (P=.03). Belapectin (2 mg/kg) was well tolerated and produced no safety signals.
Conclusions:
In a phase 2b study of 162 patients with NASH, cirrhosis, and portal hypertension, 1 year of biweekly infusion of belapectin was safe but not associated with significant reduction in HVPG or fibrosis, compared with placebo. However, in a subgroup analysis of patients without esophageal varices, 2 mg/kg belapectin did reduce HVPG and development of varices.
Galectin-3 (Gal-3), a member of the β-galactoside-binding protein family, is implicated in a wide variety of human diseases. Identification of Gal-3 inhibitors with the right combination of potency (against both human and mouse Gal-3) and pharmacokinetic properties to fully evaluate the potential of Gal-3 for therapeutic intervention has been a major challenge due to the characteristics of its binding pocket: high hydrophilicity and key structural differences between human Gal-3 and the mouse ortholog. We report the discovery of a novel series of monosaccharide-based, highly potent, and orally bioavailable inhibitors of human and mouse Gal-3. The novel monosaccharide derivatives proved to be selective for Gal-3, the only member of the chimeric type of galectins, over Gal-1 and Gal-9, representative of the prototype and tandem-repeat type of galectins, respectively. The proposed binding mode for the newly identified ligands was confirmed by an X-ray cocrystal structure of a representative analogue bound to Gal-3 protein.
Due to improvements in treatment strategies, the five-year event-free survival rate for pediatric patients with acute lymphoblastic leukemia (ALL) is 90%. However, patients with relapse and refractory disease fare much worse with 5-year overall survival rates of less than 50% in patients receiving chimeric antigen receptor T-cell therapy and fewer than 20% of patients surviving after receiving hematopoietic stem cell transplantation. These dismal outcomes for patients with relapse and refractory disease highlight the need for novel treatment regimens when current therapeutic options are exhausted.
T-cell acute lymphoblastic leukemia (T-ALL) accounts for around 15% and 25% of ALL cases in pediatric and adult populations, respectively. This disease is driven by various molecular changes including alterations in the epigenome due, in part, to deregulated epigenetic machinery such as the polycomb repressive complex 2 (PRC2). Despite this observation, and ongoing clinical trials determining the utility of epigenetic drugs for treating various hematological malignancies, the role of the epigenome in T-ALL pathogenesis and the efficacy of epigenetic modifying drugs as treatments for this disease is heavily understudied.
Galectins are members of s-type lectins which promote diverse biological processes including adhesion, signaling, and immunosuppression. Galectin-9 (Gal-9) is an emerging therapeutic target for solid cancers and hematological malignancies given that its presence is associated with poor outcomes for multiple cancers. In unpublished studies, we have found that Gal-9 is expressed on the surface of multiple human ALL subtypes with the highest basal surface expression found on T-ALL cells. To determine how this lectin impacts the function of human T-ALL cells, we treated leukemia cells with immunoglobulin control (Ig Ctrl) or anti-Gal-9 antibody (αGal-9Ab) and assessed the impact of treatment on cell cycle progression, DNA damage, and apoptosis.
We used two αGal-9Ab clones for these experiments, a commercially available antibody and LYT-200 (a proprietary antibody in Phase I clinical trials for solid tumors from PureTech Health). Treatment with the commercially available antibody, but not Ctrl Ig, increased histone 3 trimethylation (H3K2me 3/H3K4me 3) with accompanying decreases in EZH2 and RING1A protein expression in human T-ALL cell lines. Antibody-induced epigenetic changes also promoted cell cycle progression (G2M transition), DNA damage, and extensive apoptosis (>90%) in multiple human T-ALL cell lines (n>6). Importantly, LYT-200 single-agent treatment also induced cell death in human T-ALL cells, demonstrating that blocking multiple epitopes on Gal-9 is sufficient to induce T-ALL cytotoxicity. These results highlight a previously unreported role for Galectin-9 in the epigenetic regulation and survival of human T-ALL cells.
Given our observations that epigenome stability is critical for the survival of human T-ALL cells, we next sought to determine if the combination of αGal-9Ab treatment and epigenetic modifying drugs would further enhance the cytotoxicity of human T-ALL cells. We tested the combination of αGal-9Ab treatment and multiple drugs targeting either histone acetylation, methylation, or phosphorylation. Of these, we found that combining αGal-9Ab and GDC-0575 (a CHK1 inhibitor) resulted in extensive DNA damage and cytotoxicity (>98%). Mechanistically, we found αGal-9Ab treatment induces DNA damage in multiple human T-ALL lines, which leads to CHK1 activation. Given that GDC-0575 inhibits CHK1 activity, and CHK1 is a master regulator of the DNA damage response, we predict that the enhanced cytotoxicity of human T-ALL cells treated with the combination therapy results from the inability to effectively repair DNA damage induced by αGal-9Ab treatment. Our findings describe a previously unrecognized role for Gal-9 in T-ALL pathogenesis and demonstrates the cytotoxic effects αGal-9Ab treatment (including LYT-200) in preclinical models of human T-ALL.
Disclosures
Lee: PureTech Health: Research Funding. Filipovic: PureTech Health: Research Funding. Henry: PureTech Health: Research Funding.
Colorectal cancer (CRC) represents the third most common malignancy and the second leading cause of cancer-related deaths worldwide. Although immunotherapy has taken center stage in mainstream oncology, it has shown limited clinical efficacy in CRC, generating an urgent need for discovery of new biomarkers and potential therapeutic targets. Galectin-1 (Gal-1), an endogenous glycan-binding protein, induces tolerogenic programs and contributes to tumor cell evasion of immune responses. Here, we investigated the relevance of Gal-1 in CRC and explored its modulatory activity within the CD8+ regulatory T cell (Treg) compartment. Mice lacking Gal-1 (Lgals1
-/-
) developed a lower number of tumors and showed a decreased frequency of a particular population of CD8+CD122+PD-1+ Tregs in the azoxymethane-dextran sodium sulfate model of colitis-associated CRC. Moreover, silencing of tumor-derived Gal-1 in the syngeneic CT26 CRC model resulted in reduced number and attenuated immunosuppressive capacity of CD8+CD122+PD-1+ Tregs, leading to slower tumor growth. Moreover, stromal Gal-1 also influenced the fitness of CD8+ Tregs, highlighting the contribution of both tumor and stromal-derived Gal-1 to this immunoregulatory effect. Finally, bioinformatic analysis of a colorectal adenocarcinoma from The Cancer Genome Atlas dataset revealed a particular signature characterized by high CD8+ Treg score and elevated Gal-1 expression, which delineates poor prognosis in human CRC. Our findings identify CD8+CD122+PD-1+ Tregs as a target of the immunoregulatory activity of Gal-1, suggesting a potential immunotherapeutic strategy for the treatment of CRC.
Nonalcoholic fatty liver disease (NAFLD) is the leading chronic liver disease worldwide. Its more advanced subtype, nonalcoholic steatohepatitis (NASH), connotes progressive liver injury that can lead to cirrhosis and hepatocellular carcinoma. Here we provide an in-depth discussion of the underlying pathogenetic mechanisms that lead to progressive liver injury, including the metabolic origins of NAFLD, the effect of NAFLD on hepatic glucose and lipid metabolism, bile acid toxicity, macrophage dysfunction, and hepatic stellate cell activation, and consider the role of genetic, epigenetic, and environmental factors that promote fibrosis progression and risk of hepatocellular carcinoma in NASH.
Type-2 diabetes mellitus (T2DM) is an expanding global health problem, involving defective insulin secretion by pancreatic β-cells and peripheral insulin resistance, leading to impaired glucose regulation. Galectin-1, an endogenous lectin with affinity for N-acetyllactosamine (LacNAc)-containing glycans, has emerged as a regulator of inflammatory and metabolic disorders. However, the role of galectin-1 in glucose homeostasis and pancreatic β-cell function, independently of hypercaloric diets, has not been explored. Here, we identified a phenotype compatible with T2DM, involving alterations in glucose metabolism and pancreatic insulin release, in female but not male mice lacking galectin-1 (Lgals1−/−). Compared with age-matched controls, Lgals1−/female mice exhibited higher body weight and increased food intake ad libitum as well as after fasting and acute re-feeding. Although fasted serum insulin levels and insulin sensitivity were similar in both genotypes, Lgals1−/− female mice presented altered glucose tolerance and higher basal glucose levels depending on the fasting period. Insulin response to glucose overload was impaired, while pancreatic insulin content was enhanced in the absence of galectin-1. Accordingly, recombinant galectin-1 enhanced glucose-stimulated insulin release in vitro. Our study identifies a role for galectin-1 in regulating glucose metabolism through modulation of pancreatic insulin secretion, highlighting novel opportunities to control T2DM.
Blockade of the inhibitory receptor TIM-3 shows efficacy in cancer immunotherapy clinical trials. TIM-3 inhibits production of the chemokine CXCL9 by XCR1⁺ classical dendritic cells (cDC1), thereby limiting antitumor immunity in mammary carcinomas. We found that increased CXCL9 expression by splenic cDC1s upon TIM-3 blockade required type I interferons and extracellular DNA. Chemokine expression as well as combinatorial efficacy of TIM-3 blockade and paclitaxel chemotherapy were impaired by deletion of Cgas and Sting. TIM-3 blockade increased uptake of extracellular DNA by cDC1 through an endocytic process that resulted in cytoplasmic localization. DNA uptake and efficacy of TIM-3 blockade required DNA binding by HMGB1, while galectin-9-induced cell surface clustering of TIM-3 was necessary for its suppressive function. Human peripheral blood cDC1s also took up extracellular DNA upon TIM-3 blockade. Thus, TIM-3 regulates endocytosis of extracellular DNA and activation of the cytoplasmic DNA sensing cGAS-STING pathway in cDC1s, with implications for understanding the mechanisms underlying TIM-3 immunotherapy.
Galectin family is a group of glycan-binding proteins. Members in this family are expressed in different tissues, immune or non-immune cells. These molecules are important regulators in innate and adaptive immune response, performing significantly in a broad range of cellular and pathophysiological functions, such as cell proliferation, adhesion, migration, and invasion. Findings have shown that expression of galectins is abnormal in many inflammatory autoimmune diseases, such as systemic lupus erythematosus, rheumatoid arthritis, osteoarthritis, sjögren's syndrome, systemic sclerosis. Galectins also function as intracellular and extracellular disease regulators mainly through the binding of their carbohydrate recognition domain to glycoconjugates. Here, we review the state-of-the-art of the role that different galectin family members play in immune cells, contributing to the complex inflammatory diseases. Hopefully collection of the information will provide a preliminary theoretical basis for the exploration of new targets for treatment of the disorders.
Galectin-3 plays a crucial role in cancerogenesis; its targeting is a prospective pathway in cancer diagnostics and therapy. Multivalent presentation of glycans was shown to strongly increase the affinity of glycoconjugates to galectin-3. Further strengthening of interaction with galectin-3 may be accomplished using artificial glycomimetics with apt aryl substitutions. We established a new, as yet undescribed chemoenzymatic method to produce selective C-3-substituted N,N’-diacetyllactosamine glycomimetics and coupled them to human serum albumin. From a library of enzymes, only β-N-acetylhexosaminidase from Talaromyces flavus was able to efficiently synthesize the C-3-propargylated disaccharide. Various aryl residues were attached to the functionalized N,N’-diacetyllactosamine via click chemistry to assess the impact of the aromatic substitution. In ELISA-type assays with galectin-3, free glycomimetics exhibited up to 43-fold stronger inhibitory potency to Gal-3 than the lactose standard. Coupling to human serum albumin afforded multivalent neo-glycoproteins with up to 4209-fold increased inhibitory potency per glycan compared to the monovalent lactose standard. Surface plasmon resonance brought further information on the kinetics of galectin-3 inhibition. The potential of prepared neo-glycoproteins to target galectin-3 was demonstrated on colorectal adenocarcinoma DLD-1 cells. We investigated the uptake of neo-glycoproteins into cells and observed limited non-specific transport into the cytoplasm. Therefore, neo-glycoproteins primarily act as efficient scavengers of exogenous galectin-3 of cancer cells, inhibiting its interaction with the cell surface, and protecting T-lymphocytes against galectin-3-induced apoptosis. The present neo-glycoproteins combine the advantage of a straightforward synthesis, selectivity, non-toxicity, and high efficiency for targeting exogenous galectin-3, with possible application in the immunomodulatory treatment of galectin-3-overexpressing cancers.
We recently identified Galectin-1 (Gal-1), a β-galactoside-binding lectin, as a novel immune regulator in neuroblastoma (NB). Here, we characterized the tolerogenic function of Gal-1 within the CD8+ T cell compartment and further evaluated its relevance as an antigen for effective DNA vaccination against NB in a mouse model. NB cells with Gal-1 knockdown (NXS-2L) exhibited significantly reduced tumor growth compared to NXS-2 NB cells. Administration of anti-CD8 antibodies prevented this antitumor effect, with primary tumor growth comparable to that from Gal-1 (G1)-sufficient NB cells. Peptide epitope screening with online databases and in silico docking experiments predicted the sequences “FDQADLTI” (#1), “GDFKIKCV” (#2), and “AHGDANTI” (#3) to have superior H2-KK binding affinities and “KFPNRLNM” (#4), “DGDFKIKCV” (#5), and “LGKDSNNL” (#6) to have superior H2-DD binding affinities. Minigenes encoding G1-KK (#1-#2-#3), G1-DD (#4-#5-#6) and the triplet with the highest affinity, G1-H (#1-#2-#4), were generated and cloned into a ubiquitin-containing plasmid (pU). Mice receiving pU-G1-KK or pU-G-1H presented a reduction in the s.c. tumor volume and weight of up to 80% compared to control mice; this reduction was associated with increased cytotoxicity of isolated splenocytes from vaccinated animals. Vaccination with pUG1-DD showed a lower capability to suppress primary tumor progression. In conclusion, Gal-1 expression by NB negatively regulates CD8+ T cells. Vaccination with DNA plasmids encoding Gal-1 epitopes overcomes immune escape, enhances CD8+ T cell-dependent immunity and displays effective antitumor activity against NB.
Background
Aberrant activation of the WNT/β-catenin and STAT3 signaling pathways plays a critical role in cancer progression. However, direct targeting of these pathways as an anti-cancer therapeutic approach needs to be reconsidered due to its serious side effects. Here, we demonstrate that overexpression of WNT induces STAT3 activation in a galectin-3-dependent manner.Methods
We investigated how galectin-3 mediates the crosstalk between WNT/β-catenin and STAT3 signaling and whether inhibition of galectin-3 can reduce gastric cancer. The molecular mechanisms were analyzed by biochemical assays using cultured gastric cancer cells, patient tissues, and genetically engineered mice. Moreover, we confirm of therapeutic effects of GB1107, a cell-penetrating galectin-3 specific inhibitor, using orthotopic gastric cancer-bearing miceResultsIncreased levels of galectin-3 and STAT3 phosphorylation were detected in the stomach tissues of WNT1-overexpressing mouse models. Also, high expression levels and co-localization of β-catenin, pSTAT3, and galectin-3 in patients with advanced gastric cancer were correlated with a poorer prognosis. Galectin-3 depletion significantly decreased STAT3 Tyr705 phosphorylation, which regulates its nuclear localization and transcriptional activation. A peptide of galectin-3 (Y45-Q48) directly bound to the STAT3 SH2 domain and enhanced its phosphorylation. GB1107, a specific membrane-penetrating inhibitor of galectin-3, significantly reduced the activation of both STAT3 and β-catenin and inhibited tumor growth in orthotopic gastric cancer-bearing mice.Conclusions
We propose that galectin-3 mediates the crosstalk between the WNT and STAT3 signaling pathways. Therefore GB1107, a galectin-3-specific inhibitor, maybe a potent agent with anti-gastric cancer activity. Further studies are needed for its clinical application in gastric cancer therapy.
A sequence of interconnected events known as the metastatic cascade promotes tumor progression by regulating cellular and molecular interactions between tumor, stromal, endothelial, and immune cells both locally and systemically. Recently, a new concept has emerged to better describe this process by defining four attributes that metastatic cells should undergo. Every individual hallmark represents a unique trait of a metastatic cell that impacts directly in the outcome of the metastasis process. These critical features, known as the hallmarks of metastasis, include motility and invasion, modulation of the microenvironment, cell plasticity and colonization. They are hierarchically regulated at different levels by several factors, including galectins, a highly conserved family of β-galactoside-binding proteins abundantly expressed in tumor microenvironments and sites of metastasis. In this review, we discuss the role of galectins in modulating each hallmark of metastasis, highlighting novel therapeutic opportunities for treating the metastatic disease.
Hyperactive angiogenesis contributes to the immunosuppressive microenvironment important for immunotherapy. Galectin‐1, encoded by LGALS1, can trigger the vascular signaling programs and mediate the anti‐angiogenic treatment response. However, the mechanism through which galectin‐1 regulates angiogenesis is poorly understood. It has been suggested that galectin‐1 may associate with mRNAs in cells. This study applied the iRIP‐seq methodology to study the potential role of galectin‐1 as an RNA‐binding protein. We found that galectin‐1 interacts with a large number of mRNAs, with a preference for binding near stop codons and a preference for UGCA/UGGA and GAGCAG as binding motifs. Galectin‐1 binds to the mRNAs of angiogenesis‐associated genes including VEGFA, EGR1 and LAMA5, suggesting that galectin‐1 may regulate angiogenesis via its mRNA‐binding activity. We further show that shLGALS1 inhibits capillary tube formation in an in vitro angiogenesis assay and alters the expression levels of several galectin‐1‐bound angiogenesis‐associated mRNAs. These results uncover a previously unrecognized mRNA‐binding activity of galectin‐1.
Advances in molecular biology, microfluidics and bioinformatics have empowered the study of thousands or even millions of individual cells from malignant tumours at the single-cell level of resolution. This high-dimensional, multi-faceted characterization of the genomic, transcriptomic, epigenomic and proteomic features of the tumour and/or the associated immune and stromal cells enables the dissection of tumour heterogeneity, the complex interactions between tumour cells and their microenvironment, and the details of the evolutionary trajectory of each tumour. Single-cell transcriptomics, the ability to track individual T cell clones through paired sequencing of the T cell receptor genes and high-dimensional single-cell spatial analysis are all areas of particular relevance to immuno-oncology. Multidimensional biomarker signatures will increasingly be crucial to guiding clinical decision-making in each patient with cancer. High-dimensional single-cell technologies are likely to provide the resolution and richness of data required to generate such clinically relevant signatures in immuno-oncology. In this Perspective, we describe advances made using transformative single-cell analysis technologies, especially in relation to clinical response and resistance to immunotherapy, and discuss the growing utility of single-cell approaches for answering important research questions.
Galectins, a family of highly conserved β-galactoside-binding proteins, control tumor progression by modulating different hallmarks of cancer. Galectin-1 (Gal-1), a proto-type member of this family, plays essential roles in tumor angiogenesis and immunosuppression by cross-linking glycosylated receptors on the surface of endothelial and immune cells. Targeted disruption of Gal-1 suppresses tumor growth by counteracting aberrant angiogenesis and reinforcing antitumor immunity in several experimental settings. Given the multiple therapeutic benefits associated with Gal-1 blockade, several Gal-1 inhibitors, including glycan-based competitors, antagonistic peptides, aptamers and neutralizing monoclonal antibodies, have been designed and evaluated in pre-clinical tumor models. Here we report the biochemical and functional characterization of a newly developed neutralizing anti-human Gal-1 monoclonal antibody (Gal-1-mAb3), which specifically recognizes a unique epitope in Gal-1 protein and exerts both angioregulatory and immunomodulatory activities. Blockade of Gal-1 function using Gal-1-mAb3, might be relevant not only in cancer but also in other pathologic conditions characterized by aberrant angiogenesis and uncontrolled immunosuppression.
7006
Background: GCS-100 is a polysaccharide antagonist of galectin-3, a protein whose overexpression on certain tumor cells is associated with poor prognosis in cancer patients. GCS-100 has been shown to induce apoptosis of patient CLL cells ex vivo. In addition, GCS-100 potentiates the in vitro activity of other agents commonly used to treat CLL, including rituximab. This phase II clinical trial evaluated the potential of GCS-100 as a novel single-agent therapeutic for relapsed CLL. Methods: Patients with Rai Stage II or higher CLL who had relapsed after one or two prior therapies were eligible. Prior therapies included a range of chemotherapy combinations including FCR, cyclophosphamide/vincristine/rituximab, and chlorambucil/prednisone. Patients received GCS-100 i.v. at 160 mg/m ² for 5 days every 21 days until disease progression. Peripheral blood was collected on study days 1, 4, and 8 of each cycle to assess peripheral leukocyte counts and apoptosis. CD38 and Zap70 expression were assessed where possible. Results: 24 pts were enrolled;16 men and 8 women (median age 67 years, range 40–86 years, 15/24 pts were over 65 years). GCS-100 was well-tolerated. There were no cases of drug-related grade 3 or 4 hematological toxicity or other serious AE. Two patients discontinued treatment due to rash, which resolved with cessation of treatment and which has been shown to be responsive to steroids. Six (25%) patients experienced PR, including 4 patients with >50% shrinkage of lymph node lesions. Currently 6 patients remain on study with a median duration of 5 months (range 4.5–9 months). In addition, apoptosis of peripheral leukocytes was confirmed by caspase activation and by DNA fragmentation. Conclusions: GCS-100 has significant single-agent activity in relapsed CLL. Its lack of myelosuppression and potential synergy with other agents makes GCS-100 a strong candidate for further development in CLL, particularly for elderly patients for whom there is a major need for less toxic agents.
[Table: see text]
13023
Background: Galectin-3 is a galactoside-binding protein implicated in inhibition of apoptosis, and promotion of angiogenesis, metastasis, cellular proliferation by a direct association with oncogenic K-ras. Modified citrus pectin (MCP) is a complex carbohydrate derived from citrus fruit and is rich in galactoside residues. GCS-100 is an MCP capable of binding to and antagonizing galectin-3, resulting in anti-tumor activity in vitro and in vivo. Methods: GCS-100 was administered to patients with refractory solid tumors in a Phase I dose-escalating study using standard eligibility criteria. Objectives were to determine dose-limiting toxicity (DLT), maximum tolerated dose (MTD), pharmacokinetics (PK) and efficacy. Study drug was delivered by IV infusion over 1–2 hours for 5 consecutive days of a 21 day cycle. Results: 24 patients (17 F, 7 M, age 45–80 yo) were enrolled at 6 dose levels between 30–200 mg/m ² . DLT and MTD for this dosing regimen were established at 200 mg/m ² and 160 mg/m ² , respectively. DLT was a Grade 3 erythematous, maculopapular rash, resolving with systemic steroid treatment. There were no associated systemic findings, and the rash did not preclude further GCS-100 therapy. Skin biopsy revealed a vasculitis similar to findings seen in dog models. 9 other patients experienced Grade 1–2 rashes that did not require systemic treatment. The majority of adverse events (AEs) were Grade 1 or 2; the most common being nausea, vomiting, diarrhea, fatigue, fever and hyperglycemia. AEs thought to be related to treatment were rash, nausea and fatigue. Linear PKs were observed with a terminal half-life (t 1/2 ) between 30–40 h and an effective t 1/2 of 36 h. Peak GCS-100 concentrations reached 424 μg/mL at MTD. The median number of cycles was 4 (range 1–17). Best overall response per RECIST was stable disease observed in 16 patients with 6 of these patients on study for ≥ 6 months. Conclusion: Overall tolerability of GCS-100 was excellent with serum concentrations at MTD reaching levels associated with preclinical activity. Sustained periods of stable disease were achieved in patients with previously treated advanced solid tumors warranting Phase II studies.
[Table: see text]
Galectins are an endogenous family of β-galactoside-binding proteins that play complex and multifaceted roles at various stages of cancer progression, including modulation of tumor cell proliferation, signaling, adhesion, migration, invasion, epithelial-mesenchymal transition, angiogenesis and immune escape. Recently, galectins have been implicated as major therapeutic determinants that confer sensitivity or resistance to a wide range of anticancer modalities including chemotherapy, radiotherapy, targeted therapies, antiangiogenic therapies and immunotherapies. Here, we present an integrated approach to the pleiotropic functions of galectins and discuss their emerging roles with respect to mechanisms of resistance or sensitivity to anticancer therapies. Taken together, these findings suggest that targeting galectins and/or their glycosylated ligands may help to overcome resistance and to increase the clinical efficacy of anticancer strategies.
Selective galectin inhibitors are valuable research tools and could also be used as drug candidates. In that context, TD139, a thiodigalactoside galectin-3 inhibitor, is currently being evaluated clinically for the treatment of idiopathic pulmonary fibrosis. Herein, we describe a new strategy for the preparation of TD139. Starting from inexpensive levoglucosan, we used a rarely employed reaction cascade: Payne rearrangement/azidation process leading to 3-azido-galactopyranose. The latter intermediate was efficiently converted into TD139 in a few simple and practical steps.
Significance
Different immune inhibitory circuits act in concert to prevent and limit the extent of deleterious autoimmune reactions occurring during the aging process. An in-depth understanding of these pathways is critical for implementation of more selective and powerful immunomodulatory modalities capable of attenuating autoimmune inflammation. Here we show that lack of galectin-1 (an endogenous β-galactoside-binding protein) or specific N-glycosylated ligands leads to a gradual breakdown of tolerogenic programs and to the establishment of age-related salivary gland autoimmunity. This study emphasizes the role of lectin–glycan interactions in the maintenance and restoration of immune tolerance and highlights their clinical relevance and therapeutic potential in chronic inflammatory disorders.