The expressions and clinical significances of tissue and serum galectin-3 in pancreatic carcinoma

Functional structural domain synthesis of anti-pancreatic carcinoma pectin-like polysaccharide RN1

The great structural and functional diversity supports polysaccharides as favorable candidates for new drug development. Previously we reported that a drug candidate pectin-like natural polysaccharide, RN1 might target galectin-3 (Gal-3) to impede pancreatic cancer cell growth in vivo. However, the quality control of polysaccharide-based drug research faces great challenges due to the heterogeneity. A potential solution is to synthesize structurally identified subfragments of this polysaccharide as alternatives. In this work, we took RN1 as an example, and synthesized five subfragments derived from the putative repeating units of RN1. Among them, pentasaccharide 4 showed an approximative binding affinity to Gal-3 in vitro, as well as an antiproliferative activity against pancreatic BxPC-3 cells comparable to that of RN1. Further, we scaled up pentasaccharide 4 to gram-scale in an efficient synthetic route with a 6.9 % yield from D-galactose. Importantly, pentasaccharide 4 significantly suppressed the growth of pancreatic tumor in vivo. Based on the mechanism complementarity of galactin-3 inhibitor and docetaxel, the combination administration of pentasaccharide 4 and docetaxel afforded better result. The result suggested pentasaccharide 4 was one of the functional structural domains of polysaccharide RN1 and might be a leading compound for anti-pancreatic cancer new drug development.

Biomarkers in Cancer Detection, Diagnosis, and Prognosis

Biomarkers are vital in healthcare as they provide valuable insights into disease diagnosis, prognosis, treatment response, and personalized medicine. They serve as objective indicators, enabling early detection and intervention, leading to improved patient outcomes and reduced costs. Biomarkers also guide treatment decisions by predicting disease outcomes and facilitating individualized treatment plans. They play a role in monitoring disease progression, adjusting treatments, and detecting early signs of recurrence. Furthermore, biomarkers enhance drug development and clinical trials by identifying suitable patients and accelerating the approval process. In this review paper, we described a variety of biomarkers applicable for cancer detection and diagnosis, such as imaging-based diagnosis (CT, SPECT, MRI, and PET), blood-based biomarkers (proteins, genes, mRNA, and peptides), cell imaging-based diagnosis (needle biopsy and CTC), tissue imaging-based diagnosis (IHC), and genetic-based biomarkers (RNAseq, scRNAseq, and spatial transcriptomics).

Circulating Immune Proteins: Improving the Diagnosis and Clinical Outcome in Advanced Non-Small Cell Lung Cancer

Immunotherapy has been proven a viable treatment option for non-small cell lung cancer (NSCLC) treatment in patients. However, some patients still do not benefit. Finding new predictive biomarkers for immunocheckpoint inhibitor (ICI) response will improve treatment management in the clinical routine. In this regard, liquid biopsy is a useful and noninvasive alternative to surgical biopsies. In the present study, we evaluated the potential diagnostic, prognostic, and predictive value of seven different soluble mediators involved in immunoregulation. Fifty-two plasma samples from advanced NSCLC treated in first-line with pembrolizumab at baseline (PRE) and at first response assessment (FR) were analyzed. In terms of diagnostic value, our results revealed that sFGL1, sGAL-3, and sGAL-1 allowed for optimal diagnostic efficacy for cancer patients. Additionally, the combination of sFGL1 and sGAL-3 significantly improved diagnostic accuracy. Regarding the predictive value to assess patients' immune response, sCD276 levels at PRE were significantly higher in patients without tumor response (p = 0.035). Moreover, we observed that high levels of sMICB at PRE were associated with absence of clinical benefit (pembrolizumab treatment less than 6 months) (p = 0.049), and high levels of sMICB and sGAL-3 at FR are also related to a lack of clinical benefit (p = 0.027 and p = 0.03, respectively). Finally, in relation to prognosis significance, at PRE and FR, sMICB levels above the 75th percentile are related to poor progression-free survival (PFS) (p = 0.013 and p = 0.023, respectively) and overall survival (OS) (p = 0.001 and p = 0.011, respectively). An increase in sGAL3 levels at FR was associated with worse PFS (p = 0.037). Interestingly, high sGAL-3 at PRE was independently associated with PFS and OS with a hazard ratio (HR) of 2.45 (95% CI 1.14-5.25; p = 0.021) and 4.915 (95% CI 1.89-12.73; p = 0.001). In conclusion, plasma levels of sFGL1, sGAL-3, and sGAL-1 could serve as diagnostic indicators and sMICB, sCD276, and sGAL3 were linked to outcomes, suggesting their potential in assessing NSCLC under pembrolizumab treatment. Our results highlight the value of employing soluble immune biomarkers in advanced lung cancer patients treated with pembrolizumab at first-line.

Development of glycan-targeted nanoparticles as a novel therapeutic opportunity for gastric cancer treatment

Chemotherapy resistance remains a major cause of therapeutic failure in gastric cancer. The combination of genetic material such as interference RNAs (iRNAs) to silence cancer-associated genes with chemotherapeutics has become a novel approach for cancer treatment. However, finding the right target genes and developing non-toxic, highly selective nanocarrier systems remains a challenge. Here we developed a novel sialyl-Tn-targeted polylactic acid—didodecyldimethylammonium bromide nanoparticle (PLA-DDAB) nanoparticles (NPs) loaded with dsRNA targeting ST6GalNac-I and/or galectin-3 genes. Using single photon emission computed tomography (SPECT), we have demonstrated that 99mtechnetium radiolabeled sialyl-Tn-targeted nanoparticles can reach the tumor site and downregulate ST6GalNAc-I and galectin-3 RNA expression levels when injected intravenously. Furthermore, using an in vivo gastric tumor model, these nanoparticles increased the effectiveness of 5-FU in reducing tumor growth. Our findings indicate that cancer-associated glycan-targeted NPs loaded with dsRNA targeting ST6GalNAc-I and/or galectin-3 in combination with standard chemotherapy, have the potential to become a novel therapeutic tool for gastric cancer.

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 and Epithelial MUC1 Mucin-Interactions Supporting Cancer Development

Aberrant glycosylation of cell surface proteins is a very common feature of many cancers. One of the glycoproteins, which undergoes specific alterations in the glycosylation of tumor cells is epithelial MUC1 mucin, which is highly overexpressed in the malignant state. Such changes lead to the appearance of tumor associated carbohydrate antigens (TACAs) on MUC1, which are rarely seen in healthy cells. One of these structures is the Thomsen-Friedenreich disaccharide Galβ1-3GalNAc (T or TF antigen), which is typical for about 90% of cancers. It was revealed that increased expression of the T antigen has a big impact on promoting cancer progression and metastasis, among others, due to the interaction of this antigen with the β-galactose binding protein galectin-3 (Gal-3). In this review, we summarize current information about the interactions between the T antigen on MUC1 mucin and Gal-3, and their impact on cancer progression and metastasis.

Galectin-3 in prostate cancer and heart diseases: a biomarker for these two frightening pathologies?

Galectin-3 (Gal-3) belongs to galectin protein family, a type of β-galactose-binding lectin having more than one evolutionarily conserved domain of carbohydrate recognition. Gal-3 is mainly located in the cytoplasm, but it also enters the nucleus and is secreted into the extracellular environment and biological fluids such as urine, saliva, and serum. It plays an important role in many biological functions, such as angiogenesis, apoptosis, cell differentiation, cell growth, fibrosis, inflammation, host defense, cellular modification, splicing of pre-mRNA, and transformation. Many previous studies have shown that Gal-3 can be used as a diagnostic or prognostic biomarker for heart ailments, kidney diseases, and other major illnesses including cancer. Moreover, it may also play a major role in risk stratification in different diseases, and in this review, we have summarized the potential roles and application of Gal-3 as diagnostic, prognostic, and risk stratifying biomarker from previously reported studies in heart diseases and cancer, with special emphasis on prostate cancer.

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.

Diagnostic value of serum carbohydrate antigen 19-9 in pancreatic cancer: a systematic review and meta-analysis

Carbohydrate antigen 19-9 (CA19-9) is the most widely used serum biomarker for detecting pancreatic cancer (PC). Since early diagnosis is important for improving PC prognosis, a comprehensive understanding of the diagnostic performance of CA19-9 is critical. This study focused on comprehensive evaluation of the efficacy of CA19-9 in PC diagnosis. Literature research was based on the seven databases. Studies released from January 2002 to January 2022 focused on the efficacy of CA19-9 in the detection of PC were included. Summarized sensitivity, specificity, and sROC/accuracy of discrimination (AUC) were estimated. Potential publication bias was measured with Funnel plot and Egger's test. Meta-regression was performed to detect possible causes of heterogeneity. Subgroup analysis was used to assess the diagnostic efficacy of CA19-9 under different conditions. The study is registered on PROSPERO (CRD42021253861). Seventy-nine studies containing 20 991 participants who met the criteria were included. The pooled sensitivity, specificity, and AUC of CA19-9 in diagnose PC were 72% (95% CI, 71-73%), 86% (95% CI, 85-86%), and 0.8474 (95% CI, 0.8272-0.8676). Subgroup analysis suggested that the diagnostic efficiency of CA19-9 in studies with healthy controls was the highest, followed by intraductal papillary mucinous neoplasm, in pancreatitis and diabetes were consistent with the overall result. Our analysis showed that serum CA19-9 had high and stable diagnostic efficacy for PC (not affected by diabetes). Subgroup analysis showed that serum CA19-9 yielded highest effectiveness in the diagnosis of pancreatic precancerous lesions, which indicated an irreplaceable clinical value in the early detection and warning value for PC.

Mesenchymal Stromal Cells (MSCs): An Ally of B-Cell Acute Lymphoblastic Leukemia (B-ALL) Cells in Disease Maintenance and Progression within the Bone Marrow Hematopoietic Niche

Simple Summary

B-cell acute lymphoblastic leukemia (B-ALL) is the most common pediatric cancer. Even though the cure rate actually exceeds 85%, the prognosis of relapsed/refractory patients is dismal. Recent literature data indicate that the bone marrow (BM) microenvironment could play a crucial role in the onset, maintenance and progression of the disease. In particular, mesenchymal stromal cells (MSCs), which are key components of the BM niche, actively crosstalk with leukemic cells providing crucial signals for their survival and resistance to therapy. We hereby review the main mechanisms exploited by MSCs to nurture and protect B-ALL cells that could become appealing targets for innovative microenvironment remodeling therapies to be coupled with classical leukemia-directed strategies.

Abstract

Mesenchymal stromal cells (MSCs) are structural components of the bone marrow (BM) niche, where they functionally interact with hematopoietic stem cells and more differentiated progenitors, contributing to hematopoiesis regulation. A growing body of evidence is nowadays pointing to a further crucial contribution of MSCs to malignant hematopoiesis. In the context of B-cell acute lymphoblastic leukemia (B-ALL), MSCs can play a pivotal role in the definition of a leukemia-supportive microenvironment, impacting on disease pathogenesis at different steps including onset, maintenance and progression. B-ALL cells hijack the BM microenvironment, including MSCs residing in the BM niche, which in turn shelter leukemic cells and protect them from chemotherapeutic agents through different mechanisms. Evidence is now arising that altered MSCs can become precious allies to leukemic cells by providing nutrients, cytokines, pro-survivals signals and exchanging organelles, as hereafter reviewed. The study of the mechanisms exploited by MSCs to nurture and protect B-ALL blasts can be instrumental in finding new druggable candidates to target the leukemic BM microenvironment. Some of these microenvironment-targeting strategies are already in preclinical or clinical experimentation, and if coupled with leukemia-directed therapies, could represent a valuable option to improve the prognosis of relapsed/refractory patients, whose management represents an unmet medical need.

Human umbilical cord mesenchymal stem cell-derived exosomes carrying hsa-miRNA-128-3p suppress pancreatic ductal cell carcinoma by inhibiting Galectin-3

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal malignant tumors of the digestive system. Many patients are diagnosed at an advanced stage and lose eligibility for surgery. Moreover, there are few effective methods for treating pancreatic ductal cell carcinoma. Increasing attention has been given to microRNAs (miRNAs) and their regulatory roles in tumor progression. In this study, we investigated the effects of exosomes extracted from human umbilical cord mesenchymal stem cells (HUCMSCs) carrying hsa-miRNA-128-3p on pancreatic cancer cells.

METHODS

Based on existing experimental and database information, we selected Galectin-3, which is associated with pancreatic cancer, and the corresponding upstream hsa-miRNA-128-3p. We extracted HUCMSCs from a fresh umbilical cord, hsa-miRNA-128-3p was transfected into HUCMSCs, and exosomes containing hsa-miRNA-128-3p were extracted and collected. The effect of exosomes rich in hsa-miRNA-128-3p on pancreatic cancer cells was analyzed.

RESULTS

The expression of Galectin-3 in normal pancreatic duct epithelial cells was significantly lower than that in PDAC cell lines. We successfully extracted HUCMSCs from the umbilical cord and transfected hsa-miRNA-128-3p into HUCMSCs. Then we demonstrated that HUCMSC-derived exosomes with hsa-miRNA-128-3p could suppress the proliferation, invasion, and migration of PANC-1 cells in vitro by targeting Galectin-3.

CONCLUSION

Hsa-miRNA-128-3p could be considered as a potential therapy for pancreatic cancer. We provided a new idea for targeted therapy of PDAC.

Biomarkers in the diagnosis of pancreatic cancer: Are we closer to finding the golden ticket?

Pancreatic cancer (PC) is a leading cause of cancer related mortality on a global scale. The disease itself is associated with a dismal prognosis, partly due to its silent nature resulting in patients presenting with advanced disease at the time of diagnosis. To combat this, there has been an explosion in the last decade of potential candidate biomarkers in the research setting in the hope that a diagnostic biomarker may provide a glimmer of hope in what is otherwise quite a substantial clinical dilemma. Currently, serum carbohydrate antigen 19-9 is utilized in the diagnostic work-up of patients diagnosed with PC however this biomarker lacks the sensitivity and specificity associated with a gold-standard marker. In the search for a biomarker that is both sensitive and specific for the diagnosis of PC, there has been a paradigm shift towards a focus on liquid biopsy and the use of diagnostic panels which has subsequently proved to have efficacy in the diagnosis of PC. Currently, promising developments in the field of early detection on PC using diagnostic biomarkers include the detection of microRNA (miRNA) in serum and circulating tumour cells. Both these modalities, although in their infancy and yet to be widely accepted into routine clinical practice, possess merit in the early detection of PC. We reviewed over 300 biomarkers with the aim to provide an in-depth summary of the current state-of-play regarding diagnostic biomarkers in PC (serum, urinary, salivary, faecal, pancreatic juice and biliary fluid).

Galectin-3 is modulated in pancreatic cancer cells under hypoxia and nutrient deprivation

Pancreatic ductal adenocarcinoma is one of the most aggressive tumors with a microenvironment marked by hypoxia and starvation. Galectin-3 has been evaluated in solid tumors and seems to present both pro/anti-tumor effects. So, this study aims to characterize the expression of Galectin-3 from pancreatic tumor cells and analyze its influence for cell survive and motility in mimetic microenvironment. For this, cell cycle and cell death were accessed through flow cytometry. Characterization of inside and outside Galectin-3 was performed through Real-Time Quantitative Reverse Transcription PCR (qRT-PCR), immunofluorescence, Western blot, and ELISA. Consequences of Galectin-3 extracellular inhibition were investigated using cell death and scratch assays. PANC-1 showed increased Galectin-3 mRNA expression when cultivated in hypoxia for 24 and 48 h. After 24 h in simultaneously hypoxic/deprived incubation, PANC-1 shows increased Galectin-3 protein and secreted levels. For Mia PaCa-2, cultivation in deprivation was determinant for the increasing in Galectin-3 mRNA expression. When cultivated in simultaneously hypoxic/deprived condition, Mia PaCa-2 also presented increasing for the Galectin-3 secreted levels. Treatment of PANC-1 cells with lactose increased the death rate when cells were incubated simultaneously hypoxic/deprived condition. Therefore, it is possible to conclude that the microenvironmental conditions modulate the Galectin-3 expression on the transcriptional and translational levels for pancreatic cancer cells.

Targeted disruption of galectin 3 in mice delays the first wave of spermatogenesis and increases germ cell apoptosis

Galectin 3 is a multifunctional lectin implicated in cellular proliferation, differentiation, adhesion, and apoptosis. This lectin is broadly expressed in testicular somatic cells and germ cells, and is upregulated during testicular development. Since the role of galectin 3 in testicular function remains elusive, we aimed to characterize the role of galectin 3 in testicular physiology. We found that galectin 3 transgenic mice (Lgals3-/-) exhibited significantly decreased testicular weight in adulthood compared to controls. The transgenic mice also exhibited a delay to the first wave of spermatogenesis, a decrease in the number of germ cells at postnatal day 5 (P5) and P15, and defective Sertoli cell maturation. Mechanistically, we found that Insulin-like-3 (a Leydig cell marker) and enzymes involved in steroid biosynthesis were significantly upregulated in adult Lgals3-/- testes. These observations were accompanied by increased serum testosterone levels. To determine the underlying causes of the testicular atrophy, we monitored cellular apoptosis. Indeed, adult Lgals3-/- testicular cells exhibited an elevated apoptosis rate that is likely driven by downregulated Bcl-2 and upregulated Bax and Bak expression, molecules responsible for live/death cell balance. Moreover, the percentage of testicular macrophages within CD45+ cells was decreased in Lgals3-/- mice. These data suggest that galectin 3 regulates spermatogenesis initiation and Sertoli cell maturation in part, by preventing germ cells from undergoing apoptosis and regulating testosterone biosynthesis. Going forward, understanding the role of galectin 3 in testicular physiology will add important insights into the factors governing the development of germ cells and steroidogenesis and delineate novel biomarkers of testicular function.

Blood biomarkers for differential diagnosis and early detection of pancreatic cancer

Pancreatic cancer is currently the most lethal tumor entity and case numbers are rising. It will soon be the second most frequent cause of cancer-related death in the Western world. Mortality is close to incidence and patient survival after diagnosis stands at about five months. Blood-based diagnostics could be one crucial factor for improving this dismal situation and is at a stage that could make this possible. Here, we are reviewing the current state of affairs with its problems and promises, looking at various molecule types. Reported results are evaluated in the overall context. Also, we are proposing steps toward clinical utility that should advance the development toward clinical application by improving biomarker quality but also by defining distinct clinical objectives and the respective diagnostic accuracies required to achieve them. Many of the discussed points and conclusions are highly relevant to other solid tumors, too.

Serum galectin-3 as a biomarker for screening, early diagnosis, prognosis and therapeutic effect evaluation of pancreatic cancer

Galectin‐3 plays an important role in cell‐cell adhesion, macrophage activation, angiogenesis, metastasis and apoptosis and is overexpressed in pancreatic cancer. We explored the importance of galectin‐3 in the screening, early diagnosis, prognosis and therapeutic effect evaluation of pancreatic cancer. A time‐resolved fluorescence immunoassay was performed to detect serum galectin‐3 level. Serum samples were collected from healthy controls and patients with pancreatic cancer before and after different treatments, and the relationships between galectin‐3 level and clinical parameters were analysed. Among the healthy controls, one individual with an abnormally high concentration of galectin‐3 (9.85 μg/L) was diagnosed with pancreatic cancer. Compared to the pre‐operative level, galectin‐3 concentration significantly decreased in patients with radical excision 1 month after surgery (P < .05), but showed no obvious change in patients who underwent palliative resection. Additionally, among patients with radical excision, carcinoma recurrence rate was significantly higher in those with increased or unchanged galectin‐3 level. Retrospective analysis revealed the extraordinarily high value and high specificity of galectin‐3 for predicting 3‐year survival (P < .001). Thus, galectin‐3 may serve as a potential biomarker for the screening and early diagnosis of pancreatic cancer and as an independent prognostic indicator in patients with pancreatic cancer.

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.

Serum levels of advanced glycation end products and their receptors sRAGE and Galectin-3 in chronic pancreatitis

BACKGROUND

/Objectives: AGE and their receptors like RAGE and Galectin-3 can activate inflammatory pathways and have been associated with chronic inflammatory diseases. Several studies investigated the role of AGE, Galectin-3 and sRAGE in pancreatic diseases, whereas no comprehensive data for chronic pancreatitis (CP) are available.

METHODS

Serum samples from CP patients without an active inflammatory process (85 ACP; 26 NACP patients) and 40 healthy controls were collected. Levels of AGE, sRAGE and Galectin-3 were measured by ELISA. To exclude potential influences of previously described RAGE SNPs on detected serum levels, we analyzed variants rs207128, rs207060, rs1800625, and rs1800624 by melting curve technique in 378 CP patients and 338 controls.

RESULTS

AGE and Galectin-3 serum levels were significantly elevated in both ACP and NACP patients compared to controls (AGE: 56.61 ± 3.043 vs. 31.71 ± 2.308 ng/mL; p < 0.001; Galectin-3: 16.63 ± 0.6297 vs. 10.81 ± 0.4835 ng/mL; p < 0.001). In contrast, mean serum sRAGE levels were significantly reduced in CP patients compared to controls (sRAGE: 829.7 ± 37.10 vs. 1135 ± 55.74 ng/mL; p < 0.001). All results were consistent after correction for gender, age and diabetes mellitus. No genetic association with CP was found.

CONCLUSIONS

Our extensive analysis demonstrated the importance of aging related pathways in the pathogenesis of CP. As the results were consistent in ACP and NACP, both entities most likely share common pathomechanisms. Most probably the involved pathways are a general hallmark of an inflammatory state in CP that is even present in symptom-free intervals.

Plant-derived saccharides and their inhibitory potential on metastasis associated cellular processes of pancreatic ductal adenocarcinoma cells

This study intends to investigate the inhibitory potential of different plant derived saccharides on cell migration and adhesion of pancreatic ductal adenocarcinoma (PDAC) cells to microvascular liver endothelium, particularly considering the role of transmembranous galectin-3. PDAC cell lines PancTu1 and Panc1 were characterized by considerable (transmembranous) galectin-3 (Gal3) expression. SiRNA mediated Gal3 knockdown as well as treatment with differentially processed pectins and arabinogalactan-proteins (AGPs) did not impact on cell migration of either PDAC cell line. In contrast, Gal3 knockdown reduced adhesion of PDAC cells to the liver endothelial cell line TMNK-1 being more pronounced in Panc1 cells. Similarly, plant derived substances did not impact cell adhesion of PancTu1 cells while partially hydrolyzed citrus pectin (MCP), pectinase-treated MCP (MCP_Pec) and partially hydrolized AGP (AGP_TFA) clearly diminished adhesive properties of Panc1 cells. MCP_Pec or AGP_TFA could not further intensify the adhesion reducing effect of galectin-3 knockdown, indicating that these plant derived polysaccharides are able to inhibit PDAC cell adhesion to liver endothelial cells in a galectin-3 dependent manner. Overall, these data suggest an inhibitory potential of plant derived processed saccharides which have undergone chemical modification in impairing PDAC cell adhesion to liver endothelium.

Beyond immunohistochemistry and immunocytochemistry: a current perspective on galectin-3 and thyroid cancer

Introduction: Thyroid nodules are very common in the general population, most are benign, and do not require any intervention. However, often a challenge exists in discriminating benign thyroid nodules from cancer, without performing a biopsy or operation. Galectin-3 is a beta-galactoside binding protein that is involved in diverse biological processes and has been found to have increased expression in many human cancer types including thyroid cancer. As a result, recent studies have investigated its utility as a serum biomarker for thyroid cancer, as well as a novel target for in vivo molecular imaging of cancer. Additionally, given its role in tumorigenesis and cancer progression, galectin-3 targeting is currently under investigation for its potential utility as treatment for thyroid cancer.Areas covered: Recent studies of galectin-3 as a serum marker for thyroid cancer diagnosis, and in the preclinical setting as a target for cancer imaging and therapy.Expert opinion: Even though current studies evaluating galectin-3 as a serum marker and target for cancer imaging and therapy are promising, further research is required before it can be adopted into routine clinical use.

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

Background

Galectins constitute a family of β-galactoside-binding proteins, which influence various hallmarks of pancreatic cancer, including cell proliferation, invasion and migration; immune escape; and angiogenesis. Although many studies have concentrated on the role of galectins in pancreatic cancer, the results remain controversial. Hence, we performed a comprehensive meta-analysis to clarify the precise diagnostic and prognostic value of galectins in pancreatic cancer.

Methods

PubMed/MEDLINE, EMBASE and Web of Science were used to search related published literature up to July 2019. Pooled hazard ratios (HRs), diagnostic accuracy variables and related 95% confidence intervals (CIs) were calculated using STATA 14.0 software.

Results

Eleven studies including 1227 participants met our inclusion criteria. High expression of galectin family was not correlated with overall survival (OS) in pancreatic cancer (HR, 1.19; 95% CI 0.67-2.11). According to subgroup analysis, high levels of galectin-1 were significantly correlated with worse OS in pancreatic cancer (HR, 4.77; 95% CI 2.47-9.21), while high levels of tandem-repeat galectins (galectin-4 or galectin-9) predicted both better OS (HR, 0.63; 95% CI 0.46-0.86) and disease-free survival (DFS) (HR, 0.63; 95% CI 0.48-0.83). The expression levels of galectin-3 did not directly correlate with prognosis (HR, 0.99; 95% CI 0.40-2.46). The pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratios of galectin-3 were 0.64 (95% CI 0.41-0.82), 0.76 (95% CI 0.59-0.88), 2.70 (95% CI 1.21-6.1), and 0.47 (95% CI 0.23-0.98), respectively. The area under the curve (AUC) of galectin-3 was 0.77.

Conclusion

Taken together, our results suggest that high expression of galectin-1 and low levels of galectin-4 or galectin-9 are predictors of worse prognosis in pancreatic cancer patients. The expression of galectin-3 was not directly related to OS and other clinical characteristics. Although galectin-3 exhibited some diagnostic value in patients with pancreatic cancer in this meta-analysis, clinical application prospects remain to be validated. Further studies are warranted to confirm and strengthen these findings.

Galectin-3 and S100A9: Novel Diabetogenic Factors Mediating Pancreatic Cancer-Associated Diabetes

OBJECTIVE

Pancreatic cancer-associated diabetes (PCDM) is a paraneoplastic phenomenon accounting for 1% of new-onset diabetes. We aimed to identify the mediators of PCDM and evaluate their usefulness in distinguishing PCDM from type 2 diabetes.

RESEARCH DESIGN AND METHODS

Secreted proteins of MIA PaCa-2 cells were identified by proteomics, and those with ≥10-fold overexpression in transcriptome analysis were assessed by bioinformatics and glucose uptake assay to identify candidate factors. Expression of factors was compared between tumors with and without PCDM by immunohistochemistry. Serum levels were measured in a training set including PC with and without PCDM, type 2 diabetes, pancreatitis, other pancreatic/peripancreatic tumors, and control subjects (n = 50 each). Cutoff values for differentiation between PCDM and type 2 diabetes from the training set were validated in a test set (n = 41 each).

RESULTS

Galectin-3 and S100A9 were overexpressed in tumors with PCDM and dose-dependently suppressed insulin-stimulated glucose uptake in C2C12 myotubes. In the training set, serum galectin-3 and S100A9 levels were exclusively increased in patients with PCDM and distinguished PCDM from type 2 diabetes (area under the curve [AUC] galectin-3: 0.73 [95% CI 0.64-0.83]; S100A9: 0.79 [95% CI 0.70-0.87]). Similar results were observed in the test set (AUC galectin-3: 0.83 [95% CI 0.74-0.92]; S100A9: 0.77 [95% CI 0.67-0.87]), with sensitivity and specificity 72.1% and 86.1%, respectively, for galectin-3 and 69.8% and 58.1% for S100A9 in differentiating between PCDM and type 2 diabetes.

CONCLUSIONS

Galectin-3 and S100A9 are overexpressed in PCDM tumors and mediate insulin resistance. Galectin-3 and S100A9 distinguish PCDM from type 2 diabetes in subjects with new-onset diabetes.

Predictive importance of galectin-3 for recurrence of non-small cell lung cancer

OBJECTIVE

The predictive importance of galectin-3 in non-small cell lung cancer (NSCLC) has not been elucidated. We examined whether galectin-3 could serve as a predictor for tumor recurrence in NSCLC.

METHODS

In 42 consecutive patients with NSCLC who underwent radical resection, galectin-3 expression in tumor cells was examined by immunohistochemistry. Galectin-3 levels in serum were assessed before surgery and 1 month after surgery by enzyme-linked immunosorbent assays.

RESULTS

Higher expression of galectin-3 in tumor cells was associated significantly with lymphatic invasion (p = 0.049) and tumor recurrence (p = 0.001). The Kaplan-Meier curves for relapse-free survival after radical resection showed that patients with high expression of galectin-3 had significantly shorter relapse-free survival than those with low expression of galectin-3 (p < 0.001). The serum level of galectin-3 was not reduced after radical resection, and there was no significant correlation between the serum level of galectin-3 and recurrence.

CONCLUSIONS

Galectin-3 expression in tumor cells could serve as a predictive factor for recurrence, but serum level of galectin-3 is not useful for predicting NSCLC recurrence.

Correlation between S100A11 and the TGF-β1/SMAD4 pathway and its effects on the proliferation and apoptosis of pancreatic cancer cell line PANC-1

S100A11 as a S100 protein family member has been documented to play dual-direction regulation over cancer cell proliferation. We explored the role of S100A11 in the proliferation and apoptosis of pancreatic cancer cell line PANC-1 and the potential mechanisms involving the TGF-β₁/SMAD4/p21 pathway. S100A11 and TGF-β₁ protein expressions in 30 paraffin-embedded specimens were evaluated by immunohistochemistry. S100A11 and TGF-β₁ expression in PANC-1 cell line was suppressed using small interfering RNA (siRNA), respectively. Subsequently, pancreatic cancer cell apoptosis was measured by Cell Counting Kit-8 and flow cytometry, and S100A11 and TGF-β1/SMAD4/p21 pathway proteins and genes were detected with Western blotting and quantitative polymerase chain reaction (qPCR). S100A11 cytoplasmic/nuclear protein translocation was examined using NE-PER® cytoplasm/nuclear protein extraction in cells interfered with TGF-β1 siRNA. Our results showed that S100A11 expression was positively correlated with TGF-β₁ expression in pancreatic cancerous tissue. Silencing TGF-β₁ down-regulated intracellular P21^WAF1 expression by 90%, blocked S100A11 from cytoplasm entering nucleus, and enhanced cell proliferation. Silencing S100A11 down-regulated intracellular P21 expression and promoted cell apoptosis without significantly changing TGF-β₁ and SMAD4 expression. Our findings revealed that S100A11 and TGF-β₁/SMAD4 signaling pathway were related but mutually independent in regulating PANC-1 cells proliferation and apoptosis. Other independent mechanisms might be involved in S100A11's regulation of pancreatic cell growth. S100A11 could be a potential gene therapy target for pancreatic cancer.

RNA interference-mediated Gal-3 knockdown inhibits proliferation and promotes apoptosis of pancreatic cancer cells

AIM

To investigate the effect of RNA interference-mediated knockdown of galectin-3 (Gal-3) on the proliferation and apoptosis of pancreatic cancer cells and the possible mechanism involved.

METHODS

Cultured Panc-1 cells were randomly divided into a control group (untreated), an NC group (transfected with control siRNA) and a Gal-3 interference group (transfected with Gal-3-siRNA). After using small interfering RNA (siRNA) technology to interfere with the expression of Gal-3 in Panc-1 cells, Gal-3 expression was detected by RT-PCR and Western blot, cell proliferation was measured by CCK-8 assay, and cell apoptosis was tested by flow cytometry. The expression of Ki67, cleaved caspase-3, and β-catenin proteins was examined by Western blot.

RESULTS

Compared with the control group, there was no significant difference in the expression of Gal-3 mRNA (0.99 ± 0.08 vs 1.01 ± 0.06) or protein (0.36 ± 0.03 vs 0.34 ± 0.05) in the NC group (P > 0.05), while the expression of Gal-3 mRNA (0.38 ± 0.02 vs 1.01 ± 0.06) and protein (0.10 ± 0.01 vs 0.34 ± 0.05) in the Gal-3 interference group was significantly decreased (P < 0.05). Compared with the control group, RNA interference-mediated knockdown of Gal-3 significantly decreased cell proliferation (24 h: 0.55 ± 0.03 vs 0.71 ± 0.05; 48 h: 0.76 ± 0.05 vs 0.97 ± 0.06; 72 h: 1.08 ± 0.06 vs 1.32 ± 0.09), increased the percentage of cells in G0/G1 stage (79.48 ± 1.32 vs 71.52 ± 1.15), reduced the percentage of cells in S (14.26 ± 1.08 vs 18.24 ± 1.06 ) and G2/M stages (6.21 ± 0.78 vs 10.19 ± 1.52), increased apoptosis (13.26 ± 2.28 vs 5.82 ± 0.35), downregulated the expression of Ki67 (0.24 ± 0.02 vs 0.96 ± 0.07), cyclin D1 (0.26 ± 0.03 vs 0.88 ± 0.09), and β-catenin (0.42 ± 0.05 vs 0.87 ± 0.05), and upregulated the expression of cleaved caspase-3 (0.70 ± 0.06 vs 0.32 ± 0.03) (P < 0.05 for all). There was no significant difference in the above indexes between the NC group and control group (P > 0.05).

CONCLUSION

RNA interference-mediated Gal-3 knockdown can inhibit proliferation and promote apoptosis of pancreatic cancer cells via mechanisms that may be related to the inhibition of the Wnt/ beta-catenin signaling pathway.

Galectin-3 Serum Levels Could Help Clinicians Screen for Salivary Gland Tumor Patients

Objective:

To identify serum levels of galectin-3 in salivary gland cancer and healthy populations; a prospective analysis was performed on serum specimens from 105 patients with salivary gland cancer and 56 healthy persons.

Methods:

Enzyme-linked immunosorbent assay (ELISA) was used to measure levels of galectin-3 (GAL-3). Serum levels were compared between patients with salivary gland tumors and healthy control. A total of 105 patients were enrolled in the study (55 men, 50 women).

Result:

Mean age was 45.5 years. Thirty-nine patients with malignant and 66 cases with benign tumors were compared with 56 healthy participants with a mean age of 51.7. No statistically significant differences were observed when comparing GAL-3 serum levels between malignant and benign salivary gland tumor patients, but a statistically significant difference was found between case and control patients with p-values of 0.02. Serum levels of galectin-3 protein were elevated in patients with salivary gland cancer compared with the healthy population.

Conclusion:

The difference between benign and malignant tumor patients was significant, but revealed no clinic pathological characteristics in malignant tumors. To the best of the authors’ knowledge, this is the first time a study suggests that GAL-3 serum levels could help clinicians screen for salivary gland cancer.

Galectin-3 as a novel biomarker for disease diagnosis and a target for therapy (Review)

Galectin-3 is a member of the galectin family, which are β‑galactoside‑binding lectins with ≥1 evolutionary conserved carbohydrate‑recognition domain. It binds proteins in a carbohydrate‑dependent and ‑independent manner. Galectin‑3 is predominantly located in the cytoplasm; however, it shuttles into the nucleus and is secreted onto the cell surface and into biological fluids including serum and urine. It serves important functions in numerous biological activities including cell growth, apoptosis, pre‑mRNA splicing, differentiation, transformation, angiogenesis, inflammation, fibrosis and host defense. Numerous previous studies have indicated that galectin‑3 may be used as a diagnostic or prognostic biomarker for certain types of heart disease, kidney disease and cancer. With emerging evidence to support the function and application of galectin‑3, the current review aims to summarize the latest literature regarding the biomarker characteristics and potential therapeutic application of galectin‑3 in associated diseases.

Sex comb on midleg like-2 is a novel specific marker for the diagnosis of gastroenteropancreatic neuroendocrine tumors

Sex comb on midleg like-2 (SCML2) is a polycomb-group protein that encodes transcriptional repressors essential for appropriate development in the fly and in mammals. On the basis of previous findings, the present study aimed to explore the possibility of developing SCML2 into a new diagnostic marker for gastroenteropancreatic neuroendocrine tumors (GEP-NETs). A total of 64 paired GEP-NET tissues and adjacent non-tumorous tissues were obtained from patients who had undergone surgical resection between January 2009 and January 2014, and the expression of SCML2 and two neuroendocrine markers, namely synaptophysin (Syn) and chromogranin A (CgA), in the tissues was assessed by immunohistochemistry. Strong SCML2 staining was observed predominantly in the cell nuclei of GEP-NET tissues, and the overall expression rate and staining intensity of SCML2 were higher than those of Syn or CgA, respectively. Spearman rank correlation analysis demonstrated that SCML2 was not correlated with either Syn or CgA, while the combined detection of SCML2 with Syn or with CgA increased the diagnostic sensitivity to 100%. SCML2 expression in GEP-NETs was associated with several clinicopathological parameters, such as histological type, tumor grade, depth of invasion and clinical stage. Kaplan-Meier survival curves revealed that patients with higher SCML2 expression had lower survival rates than those with lower expression levels, while Cox proportional hazards regression analysis revealed that SCML2 was not an independent prognostic factor for GEP-NET patients. Therefore, SCML2 may have potential as a specific marker for joint use with other markers to improve the diagnostic efficiency of GEP-NETs.

O-glycan sialylation alters galectin-3 subcellular localization and decreases chemotherapy sensitivity in gastric cancer

ST6GalNAc-I, the sialyltransferase responsible for sialyl-Tn (sTn) synthesis, has been previously reported to be positively associated with cancer aggressiveness. Here we describe a novel sTn-dependent mechanism for chemotherapeutic resistance. We show that sTn protects cancer cells against chemotherapeutic-induced cell death by decreasing the interaction of cell surface glycan receptors with galectin-3 and increasing its intracellular accumulation. Moreover, exogenously added galectin-3 potentiated the chemotherapeutics-induced cytotoxicity in sTn non-expressing cells, while sTn overexpressing cells were protected. We also found that the expression of sTn was associated with a reduction in galectin-3-binding sites in human gastric samples tumors. ST6GalNAc-I knockdown restored galectin-3-binding sites on the cell surface and chemotherapeutics sensibility. Our results clearly demonstrate that an interruption of O-glycans extension caused by ST6GalNAc-I enzymatic activity leads to tumor cells resistance to chemotherapeutic drugs, highlighting the need for the development of novel strategies to target galectin-3 and/or ST6GalNAc-I.

Vesicular Galectin-3 levels decrease with donor age and contribute to the reduced osteo-inductive potential of human plasma derived extracellular vesicles

Aging results in a decline of physiological functions and in reduced repair capacities, in part due to impaired regenerative power of stem cells, influenced by the systemic environment. In particular osteogenic differentiation capacity (ODC) of mesenchymal stem cells (MSCs) has been shown to decrease with age, thereby contributing to reduced bone formation and an increased fracture risk.

Searching for systemic factors that might contribute to this age related decline of regenerative capacity led us to investigate plasma-derived extracellular vesicles (EVs). EVs of the elderly were found to inhibit osteogenesis compared to those of young individuals. By analyzing the differences in the vesicular content Galectin-3 was shown to be reduced in elderly-derived vesicles. While overexpression of Galectin-3 resulted in an enhanced ODC of MSCs, siRNA against Galectin-3 reduced osteogenesis. Modulation of intravesicular Galectin-3 levels correlated with an altered osteo-inductive potential indicating that vesicular Galectin-3 contributes to the biological response of MSCs to EVs. By site-directed mutagenesis we identified a phosphorylation-site on Galectin-3 mediating this effect. Finally, we showed that cell penetrating peptides comprising this phosphorylation-site are sufficient to increase ODC in MSCs. Therefore, we suggest that decrease of Galectin-3 in the plasma of elderly contributes to the age-related loss of ODC.

Association between circulating galectin-3 levels and the immunological, inflammatory and nutritional parameters in patients with colorectal cancer

Galectin-3, a β-galactoside-binding lectin, exhibits pleiotropic biological functions and has a role as one of the immunological modulators. However, the associations between circulating galectin-3 and immunological, inflammatory and nutritional parameters have not yet been fully elucidated. The serum concentration of galectin-3 was examined in association with interleukin-10 (IL-10), IL-12 and IL17 production, lymphocyte stimulation, neutrophil/lymphocyte ratio (NLR), white blood cell count (WBC), C-reactive protein (CRP) and rapid turnover proteins, including retinol-binding protein (RBP), prealbumin (PA) and transferrin (TF) in 50 patients with untreated colorectal cancers. Significant increases (P<0.05) were observed in the serum galectin-3 levels in patients with untreated colorectal cancer (9.6±4.5 ng/ml) compared with the normal controls (3.2±1.6 ng/ml). Higher serum galectin-3 concentrations were observed in patients with colon cancer (11.5±4.4 ng/ml) compared to in patients with rectal cancer (8.0±4.0 ng/ml) (P=0.005). The levels of circulating galectin-3 inversely correlated with the production of IL-10 (r=-0.59, P<0.001), and IL-12 (r=-0.69, P<0.001). Galectin-3 concentration also inversely correlated with the lymphocyte stimulation assay stimulation index (r=-0.42, P=0.021). However, the level of serum galectin-3 correlated with IL-17 production (r=0.67, P<0.001). Serum galectin-3 levels exhibited significant correlations with NLR (r=0.41, P=0.009), WBC (r=0.32, P=0.035), and CRP (r=0.63, P<0.001), and statistically significant inverse correlations with RBP (r=-0.45, P=0.002), PA (r=-0.46, P=0.001) and TF (r=-0.72, P<0.001). Galectin-3 may be one of the key factors in the regulation of immunological, inflammatory and nutritional conditions.

B-cell precursor acute lymphoblastic leukemia and stromal cells communicate through Galectin-3

The molecular interactions between B-cell precursor acute lymphoblastic leukemia (pre-B ALL) cells and stromal cells in the bone marrow that provide microenvironmentally-mediated protection against therapeutic drugs are not well-defined. Galectin-3 (Lgals3) is a multifunctional galactose-binding lectin with reported location in the nucleus, cytoplasm and extracellular space in different cell types. We previously reported that ALL cells co-cultured with stroma contain high levels of Galectin-3. We here establish that, in contrast to more mature B-lineage cancers, Galectin-3 detected in and on the ALL cells originates from stromal cells, which express it on their surface, secrete it as soluble protein and also in exosomes. Soluble and stromal-bound Galectin-3 is internalized by ALL cells, transported to the nucleus and stimulates transcription of endogenous LGALS3 mRNA. When human and mouse ALL cells develop tolerance to different drugs while in contact with protective stromal cells, Galectin-3 protein levels are consistently increased. This correlates with induction of Galectin-3 transcription in the ALL cells. Thus Galectin-3 sourced from stroma becomes supplemented by endogenous Galectin-3 production in the pre-B ALL cells that are under continuous stress from drug treatment. Our data suggest that stromal Galectin-3 may protect ALL cells through auto-induction of Galectin-3 mRNA and tonic NFκB pathway activation. Since endogenously synthesized Galectin-3 protects pre-B ALL cells against drug treatment, we identify Galectin-3 as one possible target to counteract the protective effects of stroma.

Secretome protein signature of human pancreatic cancer stem-like cells

Emerging research has demonstrated that pancreatic ductal adenocarcinoma (PDAC) contains a sub-population of cancer stem cells (CSCs) characterized by self-renewal, anchorage-independent-growth, long-term proliferation and chemoresistance. The secretome analysis of pancreatic CSCs has not yet been performed, although it may provide insight into tumour/microenvironment interactions and intracellular processes, as well as to identify potential biomarkers. To characterize the secreted proteins of pancreatic CSCs, we performed an iTRAQ-based proteomic analysis to compare the secretomes of Panc1 cancer stem-like cells (Panc1 CSCs) and parental cell line. A total of 72 proteins were found up-/down-regulated in the conditioned medium of Panc1 CSCs. The pathway analysis revealed modulation of vital physiological pathways including glycolysis, gluconeogenesis and pentose phosphate. Through ELISA immunoassays we analysed the presence of the three proteins most highly secreted by Panc1 CSCs (ceruloplasmin, galectin-3, and MARCKS) in sera of PDAC patient. ROC curve analysis suggests ceruloplasmin as promising marker for patients negative for CA19-9. Overall, our study provides a systemic secretome analysis of pancreatic CSCs revealing a number of secreted proteins which participate in pathological conditions including cancer differentiation, invasion and metastasis. They may serve as a valuable pool of proteins from which biomarkers and therapeutic targets can be identified.

BIOLOGICAL SIGNIFICANCE

The secretome of CSCs is a rich reservoir of biomarkers of cancer progression and molecular therapeutic targets, and thus is a topic of great interest for cancer research. The secretome analysis of pancreatic CSCs has not yet been performed. Recently, our group has demonstrated that Panc-1 CSCs isolated from parental cell line by using the CSC selective medium, represent a model of great importance to deepen the understanding of the biology of pancreatic adenocarcinoma. To our knowledge, this is the first proteomic study of pancreatic CSC secretome. We performed an iTRAQ-based analysis to compare the secretomes of Panc1 CSCs and Panc1 parental cell line and identified a total of 43 proteins secreted at higher level by pancreatic cancer stem cells. We found modulation of different vital physiological pathways (such as glycolysis and gluconeogenesis, pentose phosphate pathway) and the involvement of CSC secreted proteins (for example 72kDa type IV collagenase, galectin-3, alpha-actinin-4, and MARCKS) in pathological conditions including cancer differentiation, invasion and metastasis. By ELISA verification we found that MARCKS and ceruloplasmin discriminate between controls and PDAC patients; in addition ROC curve analyses indicate that MARCKS does not have diagnostic accuracy, while ceruloplasmin could be a promising marker only for patients negative for CA19-9. We think that the findings reported in our manuscript advance the understanding of the pathways implicated in tumourigenesis, metastasis and chemoresistance of pancreatic cancer, and also identify a pool of proteins from which novel candidate diagnostic and therapeutic biomarkers could be discovered.

Molecular regulation of galectin-3 expression and therapeutic implication in cancer progression

Galectin-3, a multifunctional protein, distributes inside and outside cells and plays an important role in tumor cell adhesion, proliferation, differentiation, angiogenesis, and metastasis in multiple tumors. Changes in galectin-3 expression are commonly seen in cancer and pre-cancerous conditions. Therefore, to understand the molecular regulation of galectin-3 expression could aid the development of new approach for cancer treatment. This review summarizes different expression of galectin-3 in cancer cells and patients' serum, the regulation mechanism and the potential therapeutic targets of galectin-3 in cancer progression.

CA-125, but not galectin-3, complements CA 19-9 for discriminating ductal adenocarcinoma versus non-malignant pancreatic diseases

BACKGROUND/OBJECTIVES

CA 19-9 is the gold standard biomarker of pancreatic adenocarcinoma despite several weaknesses in particular a high rate of false positives or negatives. CA-125 corresponding to MUC16 and galectin-3, a lectin able to interact with mucin-associated carbohydrates, are tumor-associated proteins. We investigated whether combined measurement of CA 19-9, galectin-3 and CA-125 may help to better discriminate pancreatic adenocarcinoma versus non-malignant pancreatic diseases.

METHODS

We evaluated by immunohistochemistry the expression of MUC4, MUC16 (CA-125) and galectin-3 in 31 pancreatic adenocarcinomas. We measured CA 19-9, CA-125 and Gal-3 in the serum from patients with pancreatic benign diseases (n = 58) or adenocarcinoma (n = 44). Clinical performance of the 3 biomarkers for cancer diagnosis and prognosis was analyzed.

RESULTS

By immunohistochemistry, MUC16 and Gal-3 were expressed in 74% and 84% of adenocarcinomas versus 0% and 3.2% in peri-tumoral regions, respectively. At the serum level, CA 19-9 and CA125 were significantly higher in patients with pancreatic adenocarcinoma whereas Gal-3 levels did not differ. The performance of CA 19-9 for cancer detection was higher than those of CA-125 or Gal-3 by ROC analysis. However, CA-125 offers the highest specificity for malignancy (81%) because of an absence of false positives among type 2 diabetic patients. Cancer deaths assessed 6 or 12 months after diagnosis varied according to the initial CA-125 level (p < 0.006).

CONCLUSION

Gal-3 is not an interesting biomarker for pancreatic adenocarcinoma detection. CA 19-9 alone exhibits the best performance but measuring CA-125 provides complementary information in terms of diagnosis and prognosis.

Towards molecular mechanisms regulating the expression of galectins in cancer cells under microenvironmental stress conditions

Galectins, a family of soluble β-galactoside-binding proteins, serve as mediators of fundamental biological processes, such as cell growth, differentiation, adhesion, migration, survival, and death. The purpose of this review is to summarize the current knowledge regarding the ways in which the expression of individual galectins differs in normal and transformed human cells exposed to various stimuli mimicking physiological and pathological microenvironmental stress conditions. A conceptual point is being made and grounded that the modulation of galectin expression profiles is a key aspect of cellular stress responses. Moreover, this modulation might be precisely regulated at transcriptional and post-transcriptional levels in the context of non-overlapping transcription factors and miRNAs specific to galectins.

Pancreatic cancer: role of the immune system in cancer progression and vaccine-based immunotherapy

Pancreatic cancer (PC) is the 5th leading cause of cancer related death in the developed world with more than 260,000 deaths annually worldwide and with a dismal 5-year survival. Surgery is the only potential hope of cure for PC, but, unfortunately, only 20% PC patients is resectable at the time of diagnosis. Therapeutic research efforts have mainly focused on improvements in radio/ chemo treatments and to date, there are only a few chemotherapeutic agents that have shown to be effective against PC, including gemcitabine with or without abraxane as well as a combination of 5-FU, leucovorin, oxaliplatin and irinotecan (the so-called FOLFIRINOX regimen). The survival of patients treated with these regimens is marginal and hence we are in urgent need of novel therapeutic approaches to treat pancreatic cancer. The success of immunotherapeutic strategies in other cancers and various evidences that pancreatic adenocarcinoma elicits antitumor immune responses, suggest that immunotherapies can be a promising alternative treatment modality for this deadly disease. PC immunotherapy treatments include passive immunotherapeutic approaches, such as the use of effector cells generated in vitro, and active immunotherapeutic strategies, which goal is to stimulate an antitumor response in vivo, by means of vaccination. In this review, we describe the immune suppressive mechanisms of pancreatic cancer and discuss recent preclinical and clinical efforts toward PC immunotherapy, including passive approaches, such as the use of antibodies and active strategies (vaccination), with a special mention of most recent treatment with CRS-207 and GVAX.

Chemically modified, non-anticoagulant heparin derivatives are potent galectin-3 binding inhibitors and inhibit circulating galectin-3-promoted metastasis

Concentrations of circulating galectin-3, a metastasis promoter, are greatly increased in cancer patients. Here we show that 2- or 6-de-O-sulfated, N-acetylated heparin derivatives are galectin-3 binding inhibitors. These chemically modified heparin derivatives inhibited galectin-3-ligand binding and abolished galectin-3-mediated cancer cell-endothelial adhesion and angiogenesis. Unlike standard heparin, these modified heparin derivatives and their ultra-low molecular weight sub-fractions had neither anticoagulant activity nor effects on E-, L- or P-selectin binding to their ligands nor detectable cytotoxicity. Intravenous injection of such heparin derivatives (with cancer cells pre-treated with galectin-3 followed by 3 subcutaneous injections of the derivatives) abolished the circulating galectin-3-mediated increase in lung metastasis of human melanoma and colon cancer cells in nude mice. Structural analysis using nuclear magnetic resonance and synchrotron radiation circular dichroism spectroscopies showed that the modified heparin derivatives bind to the galectin-3 carbohydrate-recognition domain. Thus, these chemically modified, non-anticoagulant, low-sulfated heparin derivatives are potent galectin-3 binding inhibitors with substantial potential as anti-metastasis/cancer drugs.

Galectin expression in cancer diagnosis and prognosis: A systematic review

Galectins are a family of proteins that bind to specific glycans thereby deciphering the information captured within the glycome. In the last two decades, several galectin family members have emerged as versatile modulators of tumor progression. This has initiated the development and preclinical assessment of galectin-targeting compounds. With the first compounds now entering clinical trials it is pivotal to gain insight in the diagnostic and prognostic value of galectins in cancer as this will allow a more rational selection of the patients that might benefit most from galectin-targeted therapies. Here, we present a systematic review of galectin expression in human cancer patients. Malignant transformation is frequently associated with altered galectin expression, most notably of galectin-1 and galectin-3. In most cancers, increased galectin-1 expression is associated with poor prognosis while elevated galectin-9 expression is emerging as a marker of favorable disease outcome. The prognostic value of galectin-3 appears to be tumor type dependent and the other galectins require further investigation. Regarding the latter, additional studies using larger patient cohorts are essential to fully unravel the diagnostic and prognostic value of galectin expression. Furthermore, to better compare different findings, consensus should be reached on how to assess galectin expression, not only with regard to localization within the tissue and within cellular compartments but also regarding alternative splicing and genomic variations. Finally, linking galectin expression and function to aberrant glycosylation in cancer cells will improve our understanding of how these versatile proteins can be exploited for diagnostic, prognostic and even therapeutic purposes in cancer patients.

Serum galectin-3 as a potential marker for gastric cancer

Background

The identification of cancer biomarkers can advance the possibility for early detection and better monitoring of tumor progression. The aim of this study was to assess the diagnostic and prognostic value of serum galectin-3(Gal-3) in patients with gastric cancer (GC).

Material/Methods

We measured serum Gal-3 levels using ELISA method in 87 patients with GC, 53 patients with benign gastric lesions, and 51 healthy controls.

Results

Serum levels of Gal-3 in patients with GC were significantly higher than those in benign disease patients and healthy controls (P<0.001), but no difference was found between benign disease patients and healthy controls (P=0.635). Additionally, serum Gal-3 level was associated with lymph node metastasis (P=0.001) and distant metastasis (P<0.001), whereas it was not related to gender (P=0.204), age (P=0.269), tumor size (P=0.399), location (P=0.715), TNM stage (P=0.385), differentiation (P=0.135), or invasion depth (P=0.273). The Kaplan-Meier survival analysis revealed that overall survival rates in patients with high Gal-3 levels were not significantly different that those with low Gal-3 levels (P=0.099).

Conclusions

Results of the current study suggests that serum Gal-3 represents a potential diagnostic marker for patients with GC, and may be an adjunct to determine the individual prognosis of these patients.

Galectin-3 in angiogenesis and metastasis

Galectin-3 is a member of the family of β-galactoside-binding lectins characterized by evolutionarily conserved sequences defined by structural similarities in their carbohydrate-recognition domains. Galectin-3 is a unique, chimeric protein consisting of three distinct structural motifs: (i) a short NH2 terminal domain containing a serine phosphorylation site; (ii) a repetitive proline-rich collagen-α-like sequence cleavable by matrix metalloproteases; and (iii) a globular COOH-terminal domain containing a carbohydrate-binding motif and an NWGR anti-death motif. It is ubiquitously expressed and has diverse biological functions depending on its subcellular localization. Galectin-3 is mainly found in the cytoplasm, also seen in the nucleus and can be secreted by non-classical, secretory pathways. In general, secreted galectin-3 mediates cell migration, cell adhesion and cell-cell interactions through the binding with high affinity to galactose-containing glycoproteins on the cell surface. Cytoplasmic galectin-3 exhibits anti-apoptotic activity and regulates several signal transduction pathways, whereas nuclear galectin-3 has been associated with pre-mRNA splicing and gene expression. Its unique chimeric structure enables it to interact with a plethora of ligands and modulate diverse functions such as cell growth, adhesion, migration, invasion, angiogenesis, immune function, apoptosis and endocytosis emphasizing its significance in the process of tumor progression. In this review, we have focused on the role of galectin-3 in tumor metastasis with special emphasis on angiogenesis.

High expression of peroxiredoxin 4 affects the survival time of colorectal cancer patients, but is not an independent unfavorable prognostic factor

Peroxiredoxin 4 (Prx4) has a number of important biological functions, such as efficient antioxidant capacity and promotion of cell proliferation and differentiation. The purpose of this study was to investigate the expression and significance of Prx4 in human colorectal cancer (CRC). Quantitative polymerase chain reaction (qPCR) was performed to detect Prx4 in 8 freshly frozen specimens of CRC and their adjacent normal tissues. In addition, immunohistochemical analysis was performed to detect Prx4 in 59 specimens of CRC and 26 of adjacent normal tissues. The immunohistochemical and qPCR results demonstrated that the expressions of the Prx4 gene and protein were higher in CRC compared to those in the adjacent normal tissues. The expression intensity of the Prx4 protein was correlated with depth of invasion (P=0.001), lymph node metastasis (P=0.006) and Dukes' classification (P=0.004) in CRC. The Kaplan-Meier survival curves revealed that high Prx4 expression was correlated with short survival time. However, the Cox proportional hazards regression analysis did not identify Prx4 as an independent prognostic marker for CRC (P>0.05). These results suggested that Prx4 may be associated with carcinogenesis and the development of CRC and it may be a prognostic marker for postoperative CRC patients.

S100 family signaling network and related proteins in pancreatic cancer (Review)

The occurrence and development of pancreatic cancer is a complex process convoluted by multi-pathogenies, multi-stages and multi-factors. S100 proteins are members of the S100 family that regulate multiple cellular pathways related to pancreatic cancer progression and metastasis. S100 proteins have a broad range of intracellular and extracellular functions, including the regulation of protein phosphorylation and enzyme activity, calcium homeostasis and the regulation of cytoskeletal components and transcriptional factors. S100 proteins interact with receptor for advanced glycation end-products (RAGE), p53 and p21, which play a role in the degradation of the extracellular matrix (ECM) and metastasis, and also interact with cytoskeletal proteins and the plasma membrane in pancreatic cancer progression and metastasis. S100A11 and S100P are significant tumor markers for pancreatic cancer and unfavorable predictors for the prognosis of patients who have undergone surgical resection. Recently, S100A2 has been suggested to be a negative prognostic biomarker in pancreatic cancer, and the expression of S100A6 may be an independent prognostic impact factor. The expression of S100A4 and S100P is associated with drug resistance, differentiation, metastasis and clinical outcome. This review summarizes the role and significance of the S100 family signaling network and related proteins in pancreatic cancer.

Galectin-3 in cancer

Galectin-3 (Gal-3) plays important roles in cell proliferation, adhesion, differentiation, angiogenesis and apoptosis in normal and pathologic tissues. Accumulated evidences indicate that Gal-3 is closely involved in tumor cell transformation, migration, invasion and metastasis. In this review, the associations of the expression and localization of Gal-3 as well as its potential action mechanism in tumorigenesis in a variety of cancers were summarized and concluded. Gal-3 is gaining its attraction as a potential new biomarker for the diagnosis, treatment and prognosis of certain tumors.

Circulating galectins -2, -4 and -8 in cancer patients make important contributions to the increased circulation of several cytokines and chemokines that promote angiogenesis and metastasis

Background:

Circulating concentrations of the cytokines interleukin-6 (IL-6), granulocyte colony-stimulating factor (G-CSF) and chemokines monocyte chemotatic protein 1 (MCP-1)/CCL2 and growth-regulator oncogene α (GROα)/chemokine C-X-C motif ligand 1 are commonly increased in cancer patients and they are increasingly recognised as important promoters, via divergent mechanisms, of cancer progression and metastasis.

Methods:

The effect of galectins-2, -4 and -8, whose circulating levels are highly increased in cancer patients, on endothelial secretion of cytokines was assessed in vitro by cytokine array and in mice. The relationship between serum levels of galectins and cytokines was analysed in colon and breast cancer patients.

Results:

Galectins-2, -4 and -8 at pathological concentrations induce secretion of G-CSF, IL-6, MCP-1 and GROα from the blood vascular endothelial cells in vitro and in mice. Multiple regression analysis indicates that increased circulation of these galectins accounts for 41∼83% of the variance of these cytokines in the sera of colon and breast cancer patients. The galectin-induced secretion of these cytokines/chemokines is shown to enhance the expression of endothelial cell surface adhesion molecules, causing increased cancer-endothelial adhesion and increased endothelial tubule formation.

Conclusion:

The increased circulation of galectins -2, -4 and -8 in cancer patients contributes substantially to the increased circulation of G-CSF, IL-6 and MCP-1 by interaction with the blood vascular endothelium. These cytokines and chemokines in turn enhance endothelial cell activities in angiogenesis and metastasis.