Prognostic and diagnostic significance of galectins in pancreatic cancer: a systematic review and meta-analysis

Interplay in galectin expression predicts patient outcomes in a spatially restricted manner in PDAC

BACKGROUND

Galectins (Gal's) are a family of carbohydrate-binding proteins that are known to support the tumour microenvironment through their immunosuppressive activity and ability to promote metastasis. As such they are attractive therapeutic targets, but little is known about the cellular expression pattern of galectins within the tumour and its neighbouring stromal microenvironment. Here we investigated the cellular expression pattern of Gals within pancreatic ductal adenocarcinoma (PDAC).

METHODS

Galectin gene and protein expression were analysed by scRNAseq (n=4) and immunofluorescence imaging (n=19) in fibroblasts and epithelial cells of pancreatic biopsies from PDAC patients. Galectin surface expression was also assessed on tumour adjacent normal fibroblasts and cancer associated primary fibroblasts from PDAC biopsies using flow cytometry.

RESULTS

scRNAseq revealed higher Gal-1 expression in fibroblasts and higher Gal-3 and -4 expression in epithelial cells. Both podoplanin (PDPN+, stromal/fibroblast) cells and EpCAM+ epithelial cells expressed Gal-1 protein, with highest expression seen in the stromal compartment. By contrast, significantly more Gal-3 and -4 protein was expressed in ductal cells expressing either EpCAM or PDPN, when compared to the stroma. Ductal Gal-4 cellular expression negatively correlated with ductal Gal-1, but not Gal-3 expression. Higher ductal cellular expression of Gal-1 correlated with smaller tumour size and better patient survival.

CONCLUSIONS

In summary, the intricate interplay and cell-specific expression patterns of galectins within the PDAC tissue, particularly the inverse correlation between Gal-1 and Gal-4 in ducts and its significant association with patient survival, highlights the complex molecular landscape underlying PDAC and provides valuable insights for future therapeutic interventions.

Molecular pathology and protein markers for pancreatic cancer: relevance in staging, in adjuvant therapy, in determination of minimal residual disease, and follow-up

The diagnosis and monitoring of disease through the detection of circulating protein biomarkers is a growing field in the practice of oncology. The search for more effective protein biomarkers to aid in the diagnosis and treatment of patients with pancreatic ductal adenocarcinoma (PDAC) remains a valuable area of study, given the aggressive and often occult nature of this malignancy. Liquid biopsies are attractive, as they offer a minimally invasive and cost-effective approach when compared to traditional biopsy methods and imaging modalities used for diagnosis and surveillance. Carbohydrate antigen (CA) 19-9 is currently the most commonly used serum protein biomarker for the diagnosis and monitoring of patients with PDAC, but due to its sensitivity and specificity, its utility remains limited. In this review, we examine how circulating protein biomarkers are used in the diagnosis, prognostication, and surveillance of PDAC. We also highlight protein biomarkers that are currently under investigation that have the potential to enhance our ability to detect early-stage malignancies, predict response to therapy, and monitor for recurrence, but these markers require larger prospective validation studies before they can be widely implemented. Continued efforts to identify and validate novel biomarkers will be crucial for improving the management and outcomes of patients with this challenging disease.

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-1 in Pancreatic Ductal Adenocarcinoma: Bridging Tumor Biology, Immune Evasion, and Therapeutic Opportunities

Pancreatic Ductal Adenocarcinoma (PDAC) remains one of the most challenging malignancies to treat, with a complex interplay of molecular pathways contributing to its aggressive nature. Galectin-1 (Gal-1), a member of the galectin family, has emerged as a pivotal player in the PDAC microenvironment, influencing various aspects from tumor growth and angiogenesis to immune modulation. This review provides a comprehensive overview of the multifaceted role of Galectin-1 in PDAC. We delve into its contributions to tumor stroma remodeling, angiogenesis, metabolic reprogramming, and potential implications for therapeutic interventions. The challenges associated with targeting Gal-1 are discussed, given its pleiotropic functions and complexities in different cellular conditions. Additionally, the promising prospects of Gal-1 inhibition, including the utilization of nanotechnology and theranostics, are highlighted. By integrating recent findings and shedding light on the intricacies of Gal-1's involvement in PDAC, this review aims to provide insights that could guide future research and therapeutic strategies.

Galectin-3's Complex Interactions in Pancreatic Ductal Adenocarcinoma: From Cellular Signaling to Therapeutic Potential

Galectin-3 (Gal-3) plays a multifaceted role in the development, progression, and prognosis of pancreatic ductal adenocarcinoma (PDAC). This review offers a comprehensive examination of its expression in PDAC, its interaction with various immune cells, signaling pathways, effects on apoptosis, and therapeutic resistance. Additionally, the prognostic significance of serum levels of Gal-3 is discussed, providing insights into its potential utilization as a biomarker. Critical analysis is also extended to the inhibitors of Gal-3 and their potential therapeutic applications in PDAC, offering new avenues for targeted treatments. The intricate nature of Gal-3's role in PDAC reveals a complex landscape that demands a nuanced understanding for potential therapeutic interventions and monitoring.

S100A8, S100A9 and S100A8/A9 heterodimer as novel cachexigenic factors for pancreatic cancer-induced cachexia

BACKGROUND

Cancer cachexia, occurring in ~ 80% pancreatic cancer (PC) patients overall, is a paraneoplastic syndrome mediated by cancer-induced systemic inflammation and characterized by weight loss and skeletal muscle wasting. Identifying clinically relevant PC-derived pro-inflammatory factors with cachexigenic potential may provide novel insights and therapeutic strategies.

METHODS

Pro-inflammatory factors with cachexigenic potential in PC were identified by bioinformatic analysis. The abilities of selected candidate factors in inducing skeletal muscle atrophy were investigated. Expression levels of candidate factors in tumors and sera was compared between PC patients with and without cachexia. Associations between serum levels of the candidates and weight loss were assessed in PC patients.

RESULTS

S100A8, S100A9, and S100A8/A9 were identified and shown to induce C2C12 myotube atrophy. Tumors of PC patients with cachexia had markedly elevated expression of S100A8 (P = 0.003) and S100A9 (P < 0.001). PC patients with cachexia had significantly higher serum levels of S100A8, S100A9 and S100A8/A9. Serum levels of these factors positively correlated with percentage of weight loss [correlation coefficient: S100A8: 0.33 (P < 0.001); S100A9: 0.30 (P < 0.001); S100A8/A9: 0.24 (P = 0.004)] and independently predicted the occurrence of cachexia [adjusted odds ratio (95% confidence interval) per 1ng/ml increase: S100A8 1.11 (1.02-1.21), P = 0.014; S100A9 1.10 (1.04-1.16), P = 0.001; per 1 µg/ml increase: S100A8/A9 1.04 (1.01-1.06), P = 0.009].

CONCLUSIONS

Atrophic effects of S100A8, S100A9, and S100A8/A9 indicated them as potential pathogenic factors of PC-induced cachexia. In addition, the correlation with the degree of weight loss and prediction of cachexia in PC patients implicated their potential utility in the diagnosis of PC-induced cachexia.

Galectin-9 in Gastroenterological Cancer

Immunochemotherapy has become popular in recent years. The detailed mechanisms of cancer immunity are being elucidated, and new developments are expected in the future. Apoptosis allows tissues to maintain their form, quantity, and function by eliminating excess or abnormal cells. When apoptosis is inhibited, the balance between cell division and death is disrupted and tissue homeostasis is impaired. This leads to dysfunction and the accumulation of genetically abnormal cells, which can contribute to carcinogenesis. Lectins are neither enzymes nor antibodies but proteins that bind sugar chains. Among soluble endogenous lectins, galectins interact with cell surface sugar chains outside the cell to regulate signal transduction and cell growth. On the other hand, intracellular lectins are present at the plasma membrane and regulate signal transduction by regulating receptor–ligand interactions. Galectin-9 expressed on the surface of thymocytes induces apoptosis of T lymphocytes and plays an essential role in immune self-tolerance by negative selection in the thymus. Furthermore, the administration of extracellular galectin-9 induces apoptosis of human cancer and immunodeficient cells. However, the detailed pharmacokinetics of galectin-9 in vivo have not been elucidated. In addition, the cell surface receptors involved in galectin-9-induced apoptosis of cancer cells have not been identified, and the intracellular pathways involved in apoptosis have not been fully investigated. We have previously reported that galectin-9 induces apoptosis in various gastrointestinal cancers and suppresses tumor growth. However, the mechanism of galectin-9 and apoptosis induction in gastrointestinal cancers and the detailed mechanisms involved in tumor growth inhibition remain unknown. In this article, we review the effects of galectin-9 on gastrointestinal cancers and its mechanisms.

Integrated transcriptional analysis reveals macrophage heterogeneity and macrophage-tumor cell interactions in the progression of pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease harboring significant microenvironment heterogeneity, especially for the macrophages. Tumor-associated macrophages (TAMs) orchestrate PDAC malignancy, but their dynamics during disease progression remains poorly understood. There is a pressing need to identify the molecular mechanism underlying tumor-macrophage interactions and thus design novel therapeutic strategies.

METHODS

Herein, we developed an insilico computational method incorporating bulk and single-cell transcriptome profiling to characterize macrophage heterogeneity. CellPhoneDB algorithm was applied to infer macrophage-tumor interaction networks, whereas pseudotime trajectory for dissecting cell evolution and dynamics.

RESULTS

We demonstrated myeloid compartment was an interactive hub of tumor microenvironment (TME) essential for PDAC progression. Dimensionality reduction classified seven clusters within the myeloid cells wherein five subsets of macrophages were characterized by diverse cell states and functionality. Remarkably, tissue-resident macrophages and inflammatory monocyte were identified as potential sources of TAMs. Further, we uncovered several ligand-receptor pairs lining tumor cells and macrophages. Among them, HBEGF-CD44, HBEGF-EGFR, LGALS9-CD44, LGALS9-MET, and GRN-EGFR were correlated with worse overall survival. Notably, as in vitro experiments indicated, TAM-derived HBEGF promoted proliferation and invasion of the pancreatic cancer cell line.

CONCLUSION

Together, our work deciphered a comprehensive single-cell atlas of the macrophage compartment of PDAC and provided novel macrophage-tumor interaction features with potential value in developing targeted immunotherapies and molecular diagnostics for predicting patient outcome.

Galectins Are Central Mediators of Immune Escape in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers and is highly immune tolerant. Although there is immune cell infiltration in PDAC tissues, most of the immune cells do not function properly and, therefore, the prognosis of PDAC is very poor. Galectins are carbohydrate-binding proteins that are intimately involved in the proliferation and metastasis of tumor cells and, in particular, play a crucial role in the immune evasion of tumor cells. Galectins induce abnormal functions and reduce numbers of tumor-associated macrophages (TAM), natural killer cells (NK), T cells and B cells. It further promotes fibrosis of tissues surrounding PDAC, enhances local cellular metabolism, and ultimately constructs tumor immune privileged areas to induce immune evasion behavior of tumor cells. Here, we summarize the respective mechanisms of action played by different Galectins in the process of immune escape from PDAC, focusing on the mechanism of action of Galectin-1. Galectins cause imbalance between tumor immunity and anti-tumor immunity by coordinating the function and number of immune cells, which leads to the development and progression of PDAC.

Galectin-9 expression predicts poor prognosis in hepatitis B virus-associated hepatocellular carcinoma

Objectives: The aim of this study was to explore the expression of Galectin-9 in hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC), evaluate its clinicopathological significance, and investigate whether Galecin-9 expression has prognostic value in HBV-associated HCC.

Methods: Immunohistochemistry staining was performed to examine the expression of Galectin-9 in paraffin-embedded tissues from 140 cases of HBV-associated HCC specimens. The association between Gal-9 expression, clinicopathological features and prognosis was analyzed by Kaplan-Meier method, log-rank test and Cox regression analysis. Dual immunofluorescence (IF) staining was performed to identify the cell types that have positive Gal-9 expression.

Results: Among the 140 cases of HBV-associated HCC, 39 (27.9%) cases showed high Gal-9 expression (score≥6), 21 (15%) cases showed moderate Gal-9 expression (6>score≥3), 33 (23.6%) cases showed weak Gal-9 expression (3>score>0), and 47 (33.6%) cases had no detectable Gal-9 expression (score=0). Positive Gal-9 expression (score>0) was associated with lymph node metastasis (P=0.029), Ki-67 proliferation index (P=0.009) and poor prognosis. Univariate and multivariate analyses showed that Gal-9 expression could be used as an independent prognostic marker for HBV-associated HCC. Dual IF staining indicated that Gal-9 was mainly expressed in CD68⁺CD163⁺ Kupffer cells (KCs) in HBV-associated HCC.

Conclusions: Gal-9 was specifically expressed in certain HBV-associated HCC. Positive Gal-9 expression was significantly associated with poor prognosis, and Gal-9 could be used as a prognostic marker in HBV-associated HCC. Specific expression of Gal-9 on KCs indicated it may have immunosuppressive function in HBV-associated HCC.

Galectin-8, cytokines, and the storm

Galectin-8 (Gal-8) belongs to a family of animal lectins that modulate cell adhesion, cell proliferation, apoptosis, and immune responses. Recent studies have shown that mammalian Gal-8 induces in an autocrine and paracrine manner, the expression and secretion of cytokines and chemokines such as RANKL, IL-6, IL-1β, SDF-1, and MCP-1. This involves Gal-8 binding to receptor complexes that include MRC2/uPAR/LRP1, integrins, and CD44. Receptors ligation triggers FAK, ERK, Akt, and the JNK signaling pathways, leading to induction of NF-κB that promotes cytokine expression. Indeed, immune-competent Gal-8 knockout (KO) mice express systemic lower levels of cytokines and chemokines while the opposite is true for Gal-8 transgenic animals. Cytokine and chemokine secretion, induced by Gal-8, promotes the migration of cancer cells toward cells expressing this lectin. Accordingly, Gal-8 KO mice experience reduced tumor size and smaller and fewer metastatic lesions when injected with cancer cells. These observations suggest the existence of a ‘vicious cycle’ whereby Gal-8 expression and secretion promotes the secretion of cytokines and chemokines that further promote Gal-8 expression. This ‘vicious cycle’ could enhance the development of a ‘cytokine storm’ which is a key contributor to the poor prognosis of COVID-19 patients.

Recent Developments in the Use of Glyconanoparticles and Related Quantum Dots for the Detection of Lectins, Viruses, Bacteria and Cancer Cells

Carbohydrate-coated nanoparticles-glyconanoparticles-are finding increased interest as tools in biomedicine. This compilation, mainly covering the past five years, comprises the use of gold, silver and ferrite (magnetic) nanoparticles, silicon-based and cadmium-based quantum dots. Applications in the detection of lectins/protein toxins, viruses and bacteria are covered, as well as advances in detection of cancer cells. The role of the carbohydrate moieties in stabilising nanoparticles and providing selectivity in bioassays is discussed, the issue of cytotoxicity encountered in some systems, especially semiconductor quantum dots, is also considered. Efforts to overcome the latter problem by using other types of nanoparticles, based on gold or silicon, are also presented.

Galectin-9 as a biomarker of disease severity

Galectin-9 (Gal-9) is a β-galactoside binding lectin known for its immunomodulatory role in various microbial infections. Gal-9 is expressed in all organ systems and localized in the nucleus, cell surface, cytoplasm and the extracellular matrix. It mediates host-pathogen interactions and regulates cell signalling via binding to its receptors. Gal-9 is involved in many physiological functions such as cell growth, differentiation, adhesion, communication and death. However, recent studies have emphasized on the elevated levels of Gal-9 in autoimmune disorders, viral infections, parasitic invasion, cancer, acute liver failure, atopic dermatitis, chronic kidney disease, type-2 diabetes, coronary artery disease, atherosclerosis and benign infertility-related gynecological disorders. In this paper we have reviewed the potential of Gal-9 as a reliable, sensitive and non-invasive biomarker of disease severity. Tracking changes in Gal-9 levels and its implementation as a biomarker in clinical practice will be an important tool to monitor disease activity and facilitate personalized treatment decisions.

Proteomic analysis of pancreatic ductal adenocarcinoma

INTRODUCTION

Pancreatic ductal adenocarcinoma (PDAC), which represents approximately 80% of all pancreatic cancers, is a highly aggressive malignant disease and one of the most lethal among all cancers. Overall, the 5-year survival rate among all pancreatic cancer patients is less than 9%; these rates have shown little change over the past 30 years. A more comprehensive understanding of the molecular mechanisms underlying this complex disease is crucial to the development of new diagnostic tools for early detection and disease monitoring, as well as to identify new and more effective therapeutics to improve patient outcomes.

AREA COVERED

We summarize recent advances in proteomic strategies and mass spectrometry to identify new biomarkers for early detection and monitoring of disease progression, predict response to therapy, and to identify novel proteins that have the potential to be 'druggable' therapeutic targets. An overview of proteomic studies that have been conducted to further our mechanistic understanding of metastasis and chemotherapy resistance in PDAC disease progression will also be discussed.

EXPERT COMMENTARY

The results from these PDAC proteomic studies on a variety of PDAC sample types (e.g., blood, tissue, cell lines, exosomes, etc.) provide great promise of having a significant clinical impact and improving patient outcomes.

Galectins for Diagnosis and Prognostic Assessment of Human Diseases: An Overview of Meta-Analyses

An increasing number of studies have explored the activities and functions of galectins. However, translation of these researches into clinical practice seems to be lacking. As compared to scattered individual studies, meta-analyses can provide a more comprehensive review of current evidence and reach a more unbiased and powered conclusion by synthesizing data from diverse studies. In this paper, findings from meta-analyses were reviewed to establish the role of galectins in diagnosis and prognostic assessment of various human diseases. First, in patients with cancer, galectin-1 expression is often associated with poorer survival, but galectin-9 expression is associated with better survival. Galectin-3 is a diagnostic biomarker for thyroid cancer and a predictor of worse survival in patients with colorectal cancer and improved survival in patients with gastric cancer. Second, galectin-3 is useful for diagnosis and prognostic assessment of heart failure and prediction of atrial fibrillation and its recurrence. Third, in chronic kidney disease, galectin-3 is valuable for predicting poor survival. Fourth, during pregnancy, galectin-13 is potentially helpful for identifying patients who do not have preeclampsia.

Galectin-3 Released by Pancreatic Ductal Adenocarcinoma Suppresses γδ T Cell Proliferation but Not Their Cytotoxicity

Pancreatic ductal adenocarcinoma (PDAC) is characterized by an immunosuppressive tumor microenvironment with a dense desmoplastic stroma. The expression of β-galactoside-binding protein galectin-3 is regarded as an intrinsic tumor escape mechanism for inhibition of tumor-infiltrating T cell function. In this study, we demonstrated that galectin-3 is expressed by PDAC and by γδ or αβ T cells but is only released in small amounts by either cell population. Interestingly, large amounts of galectin-3 were released during the co-culture of allogeneic in vitro expanded or allogeneic or autologous resting T cells with PDAC cells. By focusing on the co-culture of tumor cells and γδ T cells, we observed that knockdown of galectin-3 in tumor cells identified these cells as the source of secreted galectin-3. Galectin-3 released by tumor cells or addition of physiological concentrations of recombinant galectin-3 did neither further inhibit the impaired γδ T cell cytotoxicity against PDAC cells nor did it induce cell death of in vitro expanded γδ T cells. Initial proliferation of resting peripheral blood and tumor-infiltrating Vδ2-expressing γδ T cells was impaired by galectin-3 in a cell-cell-contact dependent manner. The interaction of galectin-3 with α3β1 integrin expressed by Vδ2 γδ T cells was involved in the inhibition of γδ T cell proliferation. The addition of bispecific antibodies targeting γδ T cells to PDAC cells enhanced their cytotoxic activity independent of the galectin-3 release. These results are of high relevance in the context of an in vivo application of bispecific antibodies which can enhance cytotoxic activity of γδ T cells against tumor cells but probably not their proliferation when galectin-3 is present. In contrast, adoptive transfer of in vitro expanded γδ T cells together with bispecific antibodies will enhance γδ T cell cytotoxicity and overcomes the immunosuppressive function of galectin-3.

The Galectin Family as Molecular Targets: Hopes for Defeating Pancreatic Cancer

Galectins are a family of proteins that bind β-galactose residues through a highly conserved carbohydrate recognition domain. They regulate several important biological functions, including cell proliferation, adhesion, migration, and invasion, and play critical roles during embryonic development and cell differentiation. In adults, different galectin members are expressed depending on the tissue type and can be altered during pathological processes. Numerous reports have shown the involvement of galectins in diseases, mostly inflammation and cancer. Here, we review the state-of-the-art of the role that different galectin family members play in pancreatic cancer. This tumor is predicted to become the second leading cause of cancer-related deaths in the next decade as there is still no effective treatment nor accurate diagnosis for it. We also discuss the possible translation of recent results about galectin expression and functions in pancreatic cancer into clinical interventions (i.e., diagnosis, prediction of prognosis and/or therapy) for this fatal disease.