Role and regulation mechanism of Gal-3 in non-small cell lung cancer and its potential clinical therapeutic significance

Dietary fiber as a wide pillar of colorectal cancer prevention and adjuvant therapy

Colorectal cancer is the third most incident and second most lethal type of cancer worldwide. Lifestyle and dietary patterns are the key factors for higher disease development risk. The dietary fiber intake from fruits and vegetables, mainly formed by food hydrocolloids, can help to lower the incidence of this type of neoplasia. Different food polysaccharides have applications in anti-tumoral therapy, such as coadjuvant to mainstream drugs, carriage-like properties, or direct influence on tumoral cells. Some classes include inulin, β-glucans, pectins, fucoidans, alginates, mucilages, and gums. Therefore, it is fundamental to discuss colorectal cancer mechanisms and the roles played by different polysaccharides in intestinal health. Genetic, environmental, and immunological modulation of mutated pathways regarding colorectal cancer has been explored before. Microbial diversity, byproduct formation (primarily short-chain fatty acids), inflammatory profile control, and tumoral mutated pathways regulation are thoroughly explored mechanisms by which dietary fiber sources influence a healthy gut ambiance.

The role of galectins in mediating the adhesion of circulating cells to vascular endothelium

Vascular cell adhesion is a complex orchestration of events that commonly feature lectin-ligand interactions between circulating cells, such as immune, stem, and tumor cells, and endothelial cells (ECs) lining post-capillary venules. Characteristically, circulating cell adherence to the vasculature endothelium is initiated through interactions between surface sialo-fucosylated glycoprotein ligands and lectins, specifically platelet (P)- or endothelial (E)-selectin on ECs or between leukocyte (L)-selectin on circulating leukocytes and L-selectin ligands on ECs, culminating in circulating cell extravasation. This lectin-ligand interplay enables the migration of immune cells into specific tissue sites to help maintain effective immunosurveillance and inflammation control, the homing of stem cells to bone marrow or tissues in need of repair, and, unfortunately, in some cases, the dissemination of circulating tumor cells (CTCs) to distant metastatic sites. Interestingly, there is a growing body of evidence showing that the family of β-galactoside-binding lectins, known as galectins, can also play pivotal roles in the adhesion of circulating cells to the vascular endothelium. In this review, we present contemporary knowledge on the significant roles of host- and/or tumor-derived galectin (Gal)-3, -8, and -9 in facilitating the adhesion of circulating cells to the vascular endothelium either directly by acting as bridging molecules or indirectly by triggering signaling pathways to express adhesion molecules on ECs. We also explore strategies for interfering with galectin-mediated adhesion to attenuate inflammation or hinder the metastatic seeding of CTCs, which are often rich in galectins and/or their glycan ligands.

Immunomodulation exerted by galectins: a land of opportunity in rare cancers

Rare cancers represent only 5% of newly diagnosed malignancies. However, in some cases, they account for up to 50% of the deaths attributed to cancer in their corresponding organ. Part of the reason is that treatment options are generally quite limited, non-specific, and very often, only palliative. Needless to say, research for tailored treatments is warranted. Molecules that exert immunomodulation of the tumor microenvironment are attractive drug targets. One such group is galectins. Thus, in this review we summarize the current knowledge about galectin-mediated immunomodulation in rare cancers, highlighting the research opportunities in each case.

Unveiling the potential of galectin-3 as a diagnostic biomarker for pancreatic cancer: a review

Early detection of pancreatic cancer is crucial for improving patient outcomes, and identifying reliable biomarkers is a critical research area in this field. Galectin-3 (Gal-3) is a promising candidate for utilisation as a diagnostic biomarker in early-stage pancreatic cancer. This review aims to explore the potential of Gal-3 in pancreatic cancer diagnosis and its implications for precision medicine. Rigorous validation studies are essential to establish the clinical utility of Gal-3, including large-scale investigations to assess its sensitivity, specificity, and predictive value. Combining Gal-3 with existing biomarkers and advanced imaging techniques may enhance the accuracy of early detection. Moreover, Gal-3 holds promise for risk stratification, enabling the identification of high-risk individuals who could benefit from intensified surveillance and early interventions. However, challenges in standardised testing protocols, establishing reference ranges, assay reliability, workflow integration, cost-effectiveness, and healthcare provider education must be addressed for successful implementation. Despite these challenges, Gal-3 presents significant implications for precision medicine in pancreatic cancer management. By unravelling its potential and overcoming the hurdles, Gal-3 could revolutionise early detection, risk stratification, and personalised approaches in pancreatic cancer care. Collaborative efforts and continued research will be crucial in harnessing the full potential of Gal-3 as a diagnostic biomarker for early-stage pancreatic cancer.

Galectin-3 as a biomarker in breast neoplasms: Mechanisms and applications in patient care

Galectin-3 is a member of the lectin family encoded by the LGALS3 gene on chromosome 14. It is secreted by a wide range of immune cells and mammary tumor cells. Through its activity on the tumor microenvironment, in particular on tumor-infiltrating leukocytes, galectin-3 improves the proliferation, survival, and colonizing ability of mammary neoplastic cells. Consequently, galectin-3 expression in the tumor microenvironment could worsen therapeutic outcomes of breast neoplasms and become a biomarker and a therapeutic target in combined immunotherapy in breast neoplasms. There is a limited amount of information that is available on galectin-3 in breast cancer in Africa. In this review, we analyze how galectin-3 influences the tumor microenvironment and its potential as a biomarker and therapeutic target in breast neoplasms. We aim to emphasize the significance of investigating galectin-3 in breast neoplasms in Africa based on the results of studies conducted elsewhere.

KIT Mutations Correlate with Higher Galectin Levels and Brain Metastasis in Breast and Non-Small Cell Lung Cancer

To investigate a potential role for galectins as biomarkers that enable diagnosis or prognostication of breast or non-small cell lung cancer, the serum levels of galectins -1, -3, -7, -8, and -9 of cancer patients determined by ELISA assays were compared to the mutation status of 50 known cancer-critical genes, which were determined using multiplex PCR in tumors of the same patients. Mutations in the KIT proto-oncogene, which codes for the c-Kit protein, a receptor tyrosine kinase, correlated with higher levels of galectins -1, -3, -8, and -9 in breast cancer patients and galectin-1 in non-small cell lung cancer patients. Mutations in the KIT gene were more likely found in brain metastases from both of these primary cancers. The most common KIT mutation in our panel was p.M541L, a missense mutation in the transmembrane domain of the c-Kit protein. These results demonstrate an association between KIT oncogenic signaling and elevated serum galectins in patients with metastatic disease. Changes in protein trafficking and the glycocalyx composition of cancer cells may explain the observed alterations in galectin expression. This study can be useful for the targeted selection of receptor tyrosine kinase and galectin inhibitor anti-cancer treatments.

Inhibition of galectin-3 augments the antitumor efficacy of PD-L1 blockade in non-small-cell lung cancer

Multiple clinical trials have shown that monoclonal antibodies (mAbs) against programmed death-ligand 1 (PD-1/PD-L1) can benefit patients with lung cancer by increasing their progression-free survival and overall survival. However, a significant proportion of patients do not respond to anti-PD-1/PD-L1 mAbs. In the present study, we investigated whether galectin (Gal)-3 inhibitors can enhance the antitumor effect of PD-L1 blockade. Using the NSCLC-derived cell line A549, we examined the expression of Gal-3 in lung cancer cells under hypoxic conditions and investigated the regulatory effect of Gal-3 on PD-L1 expression, which is mediated by the STAT3 pathway. We also explored whether Gal-3 inhibition can facilitate the cytotoxic effect of T cells induced by PD-L1 blockade. The effects of combined use of a Gal-3 inhibitor and PD-L1 blockade on tumor growth and T-cell function were also investigated, and we found that hypoxia increased the expression and secretion of Gal-3 by lung cancer cells. Gal-3 increased PD-L1 expression via the upregulation of STAT3 phosphorylation, and administration of a Gal-3 inhibitor enhanced the effect of PD-L1 blockade on the cytotoxic activity of T cells against cancer cells in vitro. In a mouse xenograft model, the combination of a Gal-3 inhibitor and PD-L1 blockade synergistically suppressed tumor growth. Furthermore, the administration of a Gal-3 inhibitor enhanced T-cell infiltration and granzyme B release in tumors. Collectively, our results show that Gal-3 increases PD-L1 expression in lung cancer cells and that the administration of a Gal-3 inhibitor as an adjuvant enhanced the antitumor activity of PD-L1 blockade.

Glycan array analysis of Pholiota squarrosa lectin and other fucose-oriented lectins

The α(1,6)fucose residue attached to the N-glycoprotein core is suspected to play an essential role in the progression of several types of cancer. Lectins remain the first choice for probing glycan modifications, although they may lack specificity. Thus, efforts have been made to identify new lectins with a narrower core fucose (CF) detection profile. Here, we present a comparison of the classical Aleuria aurantia lectin (AAL), Lens culinaris agglutinin (LCA) and Aspergillus oryzae lectin (AOL) with the newer Pholiota squarrosa lectin (PhoSL), which has been described as being specific for core fucosylated N-glycans. To this end, we studied the binding profiles of the four lectins using mammalian glycan arrays from the Consortium of Functional Glycomics. To validate their glycan specificity, we probed AOL, LCA and PhoSL in western-blot assays using protein extracts from eight common colorectal cancer (CRC) lines and colorectal biopsies from a small cohort of patients with CRC. The results showed that (i) LCA and PhoSL were the most specific lectins for detecting the presence of CF in a concentration-dependent manner; (ii) PhoSL exhibited the highest N-glycan sequence restriction, with preferential binding to core fucosylated paucimannosidic-type N-glycans, (iii) the recognition ability of PhoSL was highly influenced by the presence of terminal N-acetyl-lactosamine; (iv) LCA bound to paucimannosidic, bi-antennary and tri-antennary core fucosylated N-glycans and (v) AOL and AAL exhibited broader specificity towards fucosylation. Together, our results support the choice of LCA as the most appropriate lectin for CF detection, as validated in protein extracts from CRC cell lines and tissue specimens from patients with CRC.

Lectin affinity chromatography and quantitative proteomic analysis reveal that galectin-3 is associated with metastasis in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a serious cancer in East and Southeast Asia. Patients are often diagnosed at advanced stages, rendering treatment failure due to high potential of metastasis. This study identified lectin-binding glycoproteins with a potential role in NPC metastasis. Cell lysate and culture medium in highly metastatic 5-8F, and lowly-metastatic 6-10B NPC cell lines were fractionated by ConA- and WGA-affinity chromatography, and subjected to GeLC-MS/MS. A total of 232 and 197 proteins were identified in ConA-enriched fraction of 5-8F and 6-10B cell lysates respectively. In WGA-enriched fraction, 65 and 164 proteins were found in 5-8F and 6-10B cell lysates respectively. Proteins identified in culture medium for both cell lines were 223 and 85 for ConA-enriched fraction, and 94 and 124 for WGA-enriched fraction from 5-8F and 6-10B respectively. Differentially expressed proteins were functionally categorized into cell–cell adhesion, extracellular matrix, glycolysis, protein homeostasis and/or glycosylation enzymes, and lipid metabolism. Interestingly, Galectin-3 (Gal-3) was highly expressed in 5-8F cells but was lowly expressed in 6-10B cells. The Gal-3 knockdown in 5-8F cells, Gal-3 overexpression in 6-10B cells and treatment with Gal-3 inhibitor revealed that Gal-3 was responsible for metastatic phenotypes including adhesion, migration and invasion. So Galectin-3 may serve as a potential target for NPC therapeutic interventions.

Gal-3 is a potential biomarker for spinal cord injury and Gal-3 deficiency attenuates neuroinflammation through ROS/TXNIP/NLRP3 signaling pathway

Spinal cord injury (SCI) often occurs in young and middle-aged population. The present study aimed to clarify the function of Galectin-3 (Gal-3) in neuroinflammation of SCI. Sprague-Dawley (SD) rat models with SCI were established in vivo. PC12 cell model in vitro was induced by lipopolysaccharide (LPS). Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Gene chip were used to analyze the expression levels of genes in the signaling pathway. Histological assessment, ELISA and Western blotting were conducted to evaluate the effects of Gal-3 upon the SCI model. In the in vivo SD rat model, Gal-3 expression level was up-regulated. The inhibition of Gal-3 attenuated the neuroinflammation in SCI model. The inhibition of Gal-3 could also mitigate the neuroinflammation and reactive oxygen species (ROS) in in vitro model. ROS reduced the effect of Gal-3 on oxidative stress in in vitro model. Down-regulating the content of TXNIP decreased the effect of Gal-3 on neuroinflammation in in vitro model. Suppressing the level of NLRP3 could weaken the effect of Gal-3 on neuroinflammation in in vitro model. Our data highlight that the Gal-3 plays a vital role in regulating the severity of neuroinflammation of SCI by enhancing the activation of ROS/TXNIP/NLRP3 signaling pathway. In addition, inflammasome/IL-1β production probably acts as the therapeutic target in SCI.

Structure-activity relationship of Citrus segment membrane RG-I pectin against Galectin-3: The galactan is not the only important factor

Rhamnogalacturonan I (RG-I) pectin are regarded as strong galectin-3 (Gal-3) antagonist because of galactan sidechains. The present study focused on discussing the effects of more structural regions in pectin on the anti-Gal-3 activity. The water-soluble pectin (WSP) recovered from citrus canning processing water was categorized as RG-I pectin. The controlled enzymatic hydrolysis was employed to sequentially remove the α-1,5-arabinan, homogalaturonan and β-1,4-galactan in WSP. The Gal-3-binding affinity KD (kd/ka) of WSP and debranched pectins were calculated to be 0.32 μM, 0.48 μM, 0.56 μM and 1.93 μM. Moreover, based on the more sensitive cell line (MCF-7) model, the IC₃₀ value of WSP was lower than these of modified pectins, indicating decreased anti-Gal-3 activity. Our results suggested that the total amount of neutral sugar sidechains, the length of arabinan and cooperation between HG and RG-I played important roles in the anti-Gal-3 activity of WSP, not the Gal/Ara ratio or RG-I/HG ratio. These results provided a new insight into structure-activity relationship of citrus segment membrane RG-I as a galectin-3 antagonist and a new functional food.

Galectin-3 as a Next-Generation Biomarker for Detecting Early Stage of Various Diseases

Galectin-3 is a β-galactoside-binding lectin which is important in numerous biological activities in various organs, including cell proliferation, apoptotic regulation, inflammation, fibrosis, and host defense. Galectin-3 is predominantly located in the cytoplasm and expressed on the cell surface, and then often secreted into biological fluids, like serum and urine. It is also released from injured cells and inflammatory cells under various pathological conditions. Many studies have revealed that galectin-3 plays an important role as a diagnostic or prognostic biomarker for certain types of heart disease, kidney disease, viral infection, autoimmune disease, neurodegenerative disorders, and tumor formation. In particular, it has been recognized that galectin-3 is extremely useful for detecting many of these diseases in their early stages. The purpose of this article is to review and summarize the recent literature focusing on the biomarker characteristics and long-term outcome predictions of galectin-3, in not only patients with various types of diseases, but associated animal models.

Elastin-derived peptide VGVAPG affects the proliferation of mouse cortical astrocytes with the involvement of aryl hydrocarbon receptor (Ahr), peroxisome proliferator-activated receptor gamma (Pparγ), and elastin-binding protein (EBP)

During aging and ischemic and hemorrhagic stroke, elastin molecules are degraded and elastin-derived peptides are released into the brain microenvironment. Val-Gly-Val-Ala-Pro-Gly (VGVAPG) is a repeating hexapeptide in the elastin molecule. It is well documented that the peptide sequence binds with high affinity to elastin-binding protein (EBP) located on the cell surface, thereby transducing a molecular signal into the cell. The aim of our study was to investigate whether EBP, aryl hydrocarbon receptor (Ahr), and peroxisome proliferator-activated receptor gamma (Pparγ) are involved in VGVAPG-stimulated proliferation. Primary astrocytes were maintained in DMEM/F12 medium without phenol red, supplemented with 10 or 1% charcoal/dextran-treated fetal bovine serum (FBS). The cells were exposed to increasing concentrations of VGVAPG peptide, and resazurin reduction was measured. In addition, Glb1, Pparγ, and Ahr genes were silenced. After 48 h of exposure to 10 nM and 1 µM of VGVAPG peptide, the level of estradiol (E₂) and the expression of Ki67 and S100B proteins were measured. The results showed that at a wide range of concentrations, VGVAPG peptide increased the metabolism of astrocytes depending on the concentration of FBS. After silencing of Glb1, Pparγ, and Ahr genes, VGVAPG peptide did not affect the cell metabolism which suggests the involvement of all the mentioned receptors in its mechanism of action. Interestingly, in the low-FBS medium, the silencing of Glb1 gene did not result in complete inhibition of VGVAPG-stimulated proliferation. On the other hand, in the medium with 10% FBS VGVAPG increased Ki67 expression after Pparγ silencing, whereas in the medium with 1% FBS VGVAPG decreased Ki67 expression. Following the application of Ahr siRNA, VGVAPG peptide decreased the production of E₂ and increased the expression of Ki67 and S100B proteins.

Targeting Programmed Fusobacterium nucleatum Fap2 for Colorectal Cancer Therapy

Colorectal patients generally have the maximum counts of Fusobacterium nucleatum (F. nucleatum) in tumors and elevate colorectal adenomas and carcinomas, which show the lowest rate of human survival. Hence, F. nucleatum is a diagnostic marker of colorectal cancer (CRC). Studies demonstrated that targeting fusobacterial Fap2 or polysaccharide of the host epithelium may decrease fusobacteria count in the CRC. Attenuated F. nucleatum-Fap2 prevents transmembrane signals and inhibits tumorigenesis inducing mechanisms. Hence, in this review, we hypothesized that application of genetically programmed fusobacterium can be skillful and thus reduce fusobacterium in the CRC. Genetically programmed F. nucleatum is a promising antitumor strategy.