Wisteria floribunda agglutinin-positive mucin 1 is a sensitive biliary marker for human cholangiocarcinoma

Recent Advancement in Diagnosis of Biliary Tract Cancer through Pathological and Molecular Classifications

Biliary tract cancers (BTCs), including intrahepatic, perihilar, and distal cholangiocarcinomas, as well as gallbladder cancer, are a diverse group of cancers that exhibit unique molecular characteristics in each of their anatomic and pathological subtypes. The pathological classification of BTCs compromises distinct growth patterns, including mass forming, periductal infiltrating, and intraductal growing types, which can be identified through gross examination. The small-duct and large-duct types of intrahepatic cholangiocarcinoma have been recently introduced into the WHO classification. The presentation of typical clinical symptoms, as well as the extensive utilization of radiological, endoscopic, and molecular diagnostic methods, is thoroughly detailed in the description. To overcome the limitations of traditional tissue acquisition methods, new diagnostic modalities are being explored. The treatment landscape is also rapidly evolving owing to the emergence of distinct subgroups with unique molecular alterations and corresponding targeted therapies. Furthermore, we emphasize the crucial aspects of diagnosing BTC in practical clinical settings.

Role of Wisteria floribunda agglutinin binding glycans in carcinogenesis and metastasis of cholangiocarcinoma

Aberrant glycosylation is an important factor in facilitating tumor progression and therapeutic resistance. In this study, using Wisteria floribunda agglutinin (WFA), we examined the expression of WFA-binding glycans (WFAG) in cholangiocarcinoma (CCA). The results showed that WFAG was highly detected in precancerous and cancerous lesions of human CCA tissues, although it was rarely detected in normal bile ducts. The positive signal of WFAG in the cancerous lesion accounted for 96.2% (50/52) of the cases. Overexpression of WFAG was significantly associated with lymph node and distant metastasis (P < 0.05). The study using the CCA hamster model showed that WFAG is elevated in preneoplastic and neoplastic bile ducts as early as 1 month after being infected with liver fluke and exposed to N-nitrosodimethylamine. Functional analysis was performed to reveal the role of WFAG in CCA. The CCA cell lines KKU-213A and KKU-213B were treated with WFA, followed by migration assay. Our data suggested that WFAG facilitates the migration of CCA cells via the activation of the Akt and ERK signaling pathways. In conclusion, we have demonstrated the association of WFAG with carcinogenesis and metastasis of CCA, suggesting its potential as a target for the treatment of the disease.

An improved evanescent fluorescence scanner suitable for high-resolution glycome mapping of formalin-fixed paraffin-embedded tissue sections

Lectin microarray (LMA) is a high-throughput platform that enables the rapid and sensitive analysis of N- and O-glycans attached to glycoproteins in biological samples, including formalin-fixed paraffin-embedded (FFPE) tissue sections. Here, we evaluated the sensitivity of the advanced scanner based on the evanescent-field fluorescence principle, which is equipped with a 1× infinity correction optical system and a high-end complementary metal-oxide semiconductor (CMOS) image sensor in digital binning mode. Using various glycoprotein samples, we estimated that the mGSR1200-CMOS scanner has at least fourfold higher sensitivity for the lower limit of linearity range than that of a previous charge-coupled device scanner (mGSR1200). A subsequent sensitivity test using HEK293T cell lysates demonstrated that cell glycomic profiling could be performed with only three cells, which has the potential for the glycomic profiling of cell subpopulations. Thus, we examined its application in tissue glycome mapping, as indicated in the online LM-GlycomeAtlas database. To achieve fine glycome mapping, we refined the laser microdissection-assisted LMA procedure to analyze FFPE tissue sections. In this protocol, it was sufficient to collect 0.1 mm2 of each of the tissue fragments from 5-μm-thick sections, which differentiated the glycomic profile between the glomerulus and renal tubules of a normal mouse kidney. In conclusion, the improved LMA enables high-resolution spatial analysis, which expands the possibilities of its application classifying cell subpopulations in clinical FFPE tissue specimens. This will be used in the discovery phase for the development of novel glyco-biomarkers and therapeutic targets, and to expand the range of target diseases.

Bile liquid biopsy in biliary tract cancer

Biliary tract cancers are heterogeneous in etiology, morphology and molecular characteristics thus impacting disease management. Diagnosis is complex and prognosis poor. The advent of liquid biopsy has provided a unique approach to more thoroughly understand tumor biology in general and biliary tract cancers specifically. Due to their minimally invasive nature, liquid biopsy can be used to serially monitor disease progression and allow real-time monitoring of tumor genetic profiles as well as therapeutic response. Due to the unique anatomic location of biliary tract cancer, bile provides a promising biologic fluid for this purpose. This review focuses on the composition of bile and the use of these various components, ie, cells, extracellular vesicles, nucleic acids, proteins and metabolites as potential biomarkers. Based on the disease characteristics and research status of biliary tract cancer, considerable effort should be made to increase understanding of this disease, promote research and development into early diagnosis, develop efficient diagnostic, therapeutic and prognostic markers.

Research progress of bile biomarkers and their immunoregulatory role in biliary tract cancers

Biliary tract cancers (BTCs), including cholangiocarcinoma and gallbladder carcinoma, originate from the biliary epithelium and have a poor prognosis. Surgery is the only choice for cure in the early stage of disease. However, most patients are diagnosed in the advanced stage and lose the chance for surgery. Early diagnosis could significantly improve the prognosis of patients. Bile has complex components and is in direct contact with biliary tract tumors. Bile components are closely related to the occurrence and development of biliary tract tumors and may be applied as biomarkers for BTCs. Meanwhile, arising evidence has confirmed the immunoregulatory role of bile components. In this review, we aim to summarize and discuss the relationship between bile components and biliary tract cancers and their ability as biomarkers for BTCs, highlighting the role of bile components in regulating immune response, and their promising application prospects.

Diagnosis Biomarkers of Cholangiocarcinoma in Human Bile: An Evidence-Based Study

Simple Summary

A liquid biopsy has the characteristics of low trauma and easy acquisition in the diagnosis of cholangiocarcinoma. Many researchers try to find diagnostic or prognostic biomarkers of CCA through blood, urine, bile and other body fluids. Due to the close proximity of bile to the lesion and the stable nature, bile gradually comes into people’s view. The evaluation of human bile diagnostic biomarkers is not only to the benefit of screening more suitable clinical markers but also of exploring the pathological changes of the disease.

Abstract

Cholangiocarcinoma (CCA) is a multifactorial malignant tumor of the biliary tract, and the incidence of CCA is increasing in recent years. At present, the diagnosis of CCA mainly depends on imaging and invasive examination, with limited specificity and sensitivity and late detection. The early diagnosis of CCA always faces the dilemma of lacking specific diagnostic biomarkers. Non-invasive methods to assess the degree of CAA have been developed throughout the last decades. Among the many specimens looking for CCA biomarkers, bile has gotten a lot of attention lately. This paper mainly summarizes the recent developments in the current research on the diagnostic biomarkers for CCA in human bile at the levels of the gene, protein, metabolite, extracellular vesicles and volatile organic compounds.

Phaseolus vulgaris Erythroagglutinin (PHA-E)-Positive Ceruloplasmin Acts as a Potential Biomarker in Pancreatic Cancer Diagnosis

Pancreatic cancer (PC) remains one of the top 10 causes of cancer-related death in recent years. Approximately 80% of PC patients are diagnosed at the middle or advanced stage and miss the opportunity for surgery. The demand for early diagnostic methods and reliable biomarkers is increasing, although a number of tumor markers such as CA19-9 and CEA have already been utilized in clinics. In this study, we analyzed the alteration of N-glycan of serum glycoproteins by mass spectrometry and lectin blotting. The results showed that bisecting GlcNAc structures of glycoproteins are significantly increased in PC patients' sera. With Phaseolus vulgaris Erythroagglutinin (PHA-E) lectin that specifically recognizes bisecting GlcNAc N-glycans, the serum glycoproteins bearing bisecting GlcNAc in PC patients' sera were pulled down and identified by nano-LC-MS/MS. Among them, ceruloplasmin (Cp) was screened out with a satisfied sensitivity and specificity in identifying PC from acute pancreatitis patients (AUC: 0.757) and normal healthy persons (AUC: 0.972), suggesting a close association between Cp and PC development and diagnosis. To prove that, the Cp expression in tumor tissues of PC patients was examined. The results showed that Cp was significantly upregulated in PC tissues compared to that in adjacent normal tissues. All these results suggested that PHA-E-positive Cp could be a potential PC-specific glycoprotein marker to distinguish PC patients from acute pancreatitis patients and normal persons.

Sensitive New Assay System for Serum Wisteria floribunda Agglutinin-Reactive Ceruloplasmin That Distinguishes Ovarian Clear Cell Carcinoma from Endometrioma

Wisteria floribunda agglutinin (WFA)-reactive ceruloplasmin (CP) is a candidate marker for ovarian clear cell carcinoma (CCC) reported in our previous paper. Herein, a new measurement system was developed to investigate its potential as a serum marker for CCC. Site-specific glycome analysis using liquid chromatography/mass spectrometry showed that WFA-CP from CCC binds to WFA via the GalNAcβ1,4GlcNAc (LDN) structure. We used mutant recombinant WFA (rWFA), which has a high specificity to the LDN structure, instead of native WFA, to increase the specificity of the serum sample measurement. To improve the sensitivity, we used a surface plasmon field-enhanced fluorescence spectroscopy immunoassay system, which is approximately 100 times more sensitive than the conventional sandwich enzyme-linked immunosorbent assay system. With these two improvements, the specificity and sensitivity of the serum rWFA-CP measurement were dramatically improved, clearly distinguishing CCC from endometrioma, from which CCC originates. This rWFA-CP assay can be used clinically for the serodiagnosis of early-stage CCC, which is difficult to detect with existing serum markers.

Tissue Glycome Mapping: Lectin Microarray-Based Differential Glycomic Analysis of Formalin-Fixed Paraffin-Embedded Tissue Sections

Lectin microarray (LMA) is a high-sensitive glycan analysis technology used to obtain global glycomic profiles of both N- and O-glycans attached not only to purified glycoproteins but also to crude glycoprotein samples. Through additional use of laser microdissection (LMD) for tissue collection, we developed an LMA-based glycomic profiling technique for a specific type of cells in a tiny area of formalin-fixed paraffin-embedded (FFPE) tissue sections. This LMD-LMA method makes it possible to obtain reproducible tissue glycomic profiles that can be compared with each other, using a unified protocol for all procedures, including FFPE tissue preparation, tissue staining, protein extraction and labeling, and LMA analysis. Here, we describe the standardized LMD-LMA procedure for a "tissue glycome mapping" approach, which facilitates an in-depth understanding of region- and tissue-specific protein glycosylation. We also describe potential applications of the spatial tissue glycomic profiles, including histochemical analysis for evaluating distribution of lectin ligands and a fluorescence LMD-LMA method for cell type-selective glycomic profiling using a cell type-specific probe, composed of a lectin and an antibody. The protocols presented here will accelerate the effective utilization of FFPE tissue specimens by providing tissue glycome maps for the discovery of the biological roles and disease-related alterations of protein glycosylation.

Precision N-glycoproteomics reveals elevated LacdiNAc as a novel signature of intrahepatic cholangiocarcinoma

Primary liver cancer, mainly comprising hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC), remains a major global health problem. Although ICC is clinically different from HCC, their molecular differences are still largely unclear. In this study, precision N‐glycoproteomic analysis was performed on both ICC and HCC tumors as well as paracancer tissues to investigate their aberrant site‐specific N‐glycosylation. By using our newly developed glycoproteomic methods and novel algorithm, termed ‘StrucGP’, a total of 486 N‐glycan structures attached on 1235 glycosites were identified from 894 glycoproteins in ICC and HCC tumors. Notably, glycans with uncommon LacdiNAc (GalNAcβ1‐4GlcNAc) structures were distinguished from their isomeric glycans. In addition to several bi‐antennary and/or bisecting glycans that were commonly elevated in ICC and HCC, a number of LacdiNAc‐containing, tri‐antennary, and core‐fucosylated glycans were uniquely increased in ICC. More interestingly, almost all LacdiNAc‐containing N‐glycopeptides were enhanced in ICC tumor but not in HCC tumor, and this phenomenon was further confirmed by lectin histochemistry and the high expression of β1‐4 GalNAc transferases in ICC at both mRNA and protein expression levels. The novel N‐glycan alterations uniquely detected in ICC provide a valuable resource for future studies regarding to the discovery of ICC diagnostic biomarkers, therapeutic targets, and mechanism investigations.

A Neoglycoprotein-Immobilized Fluorescent Magnetic Bead Suspension Multiplex Array for Galectin-Binding Studies

Carbohydrate-protein conjugates have diverse applications. They have been used clinically as vaccines against bacterial infection and have been developed for high-throughput assays to elucidate the ligand specificities of glycan-binding proteins (GBPs) and antibodies. Here, we report an effective process that combines highly efficient chemoenzymatic synthesis of carbohydrates, production of carbohydrate-bovine serum albumin (glycan-BSA) conjugates using a squarate linker, and convenient immobilization of the resulting neoglycoproteins on carboxylate-coated fluorescent magnetic beads for the development of a suspension multiplex array platform. A glycan-BSA-bead array containing BSA and 50 glycan-BSA conjugates with tuned glycan valency was generated. The binding profiles of six plant lectins with binding preference towards Gal and/or GalNAc, as well as human galectin-3 and galectin-8, were readily obtained. Our results provide useful information to understand the multivalent glycan-binding properties of human galectins. The neoglycoprotein-immobilized fluorescent magnetic bead suspension multiplex array is a robust and flexible platform for rapid analysis of glycan and GBP interactions and will find broad applications.

N-glycan structures of Wisteria floribunda agglutinin-positive Mac2 binding protein in the serum of patients with liver fibrosis†

The extent of liver fibrosis predicts prognosis and is important for determining treatment strategies for chronic hepatitis. During the fibrosis progression, serum levels of Mac2 binding protein (M2BP) increase and the N-glycan structure changes to enable binding to Wisteria floribunda agglutinin (WFA) lectin. As a novel diagnostic marker, glycosylation isomer of M2BP (M2BPGi) has been developed. However, its glycan structures recognized by WFA are unclear. In this study, we analyzed site-specific N-glycan structures of serum M2BP using Glyco-RIDGE (Glycan heterogeneity-based Relational IDentification of Glycopeptide signals on Elution profile) method. We evaluated five sample types: 1) M2BP immunoprecipitated from normal healthy sera (NHS-IP(+)), 2) M2BP immunoprecipitated from sera of patients with liver cirrhosis (stage 4; F4-IP(+)), 3) M2BP captured with WFA from serum of patients with liver cirrhosis (stage 4; F4-WFA(+)), 4) recombinant M2BP produced by HEK293 cells (rM2BP), and 5) WFA-captured rM2BP (rM2BP-WFA(+)). In NHS-IP(+) M2BP, bi-antennary N-glycan was the main structure, and LacNAc extended to its branches. In F4-IP(+) M2BP, many branched structures, including tri-antennary and tetra-antennary N-glycans, were found. F4-WFA(+) showed a remarkable increase in branched structures relative to the quantity before enrichment. In recombinant M2BP, both no sialylated-LacdiNAc and -branched LacNAc structures were emerged. The LacdiNAc structure was not found in serum M2BP. Glycosidase-assisted HISCL assays suggest that, reactivity with WFA of both serum and recombinant M2BP depends on unsialylated and branched LacNAc, and in part of recombinant, depends on LacdiNAc. On M2BPGi, the highly branched LacNAc, probably dense cluster of LacNAc, would be recognized by WFA.

A Novel Serum Glycobiomarker for Diagnosis and Prognosis of Cholangiocarcinoma Detected by Butea monosperma Agglutinin

Plant lectins are widely used in medical glycosciences and glycotechnology. Many lectin-based techniques have been applied for the detection of disease-associated glycans and glycoconjugates. In this study, Butea monosperma agglutinin (BMA), a lectin purified from seeds of the medicinal plant Butea monosperma, was used for the detection of cholangiocarcinoma (CCA)-associated glycans. Expression of BMA-binding N-acetyl galactosamine/galactose (GalNAc/Gal)-associated glycan (BMAG) in CCA tissues was determined using BMA lectin histochemistry; the results showed that BMAG was undetectable in normal bile ducts and drastically increased in preneoplastic bile ducts and CCA. The study in hamsters showed that an increase of BMAG was associated with carcinogenesis of CCA. Using an in-house double BMA sandwich enzyme-linked lectin assay, BMAG was highly detected in the sera of CCA patients. The level of serum BMAG in CCA patients (N = 83) was significantly higher than non-CCA controls (N = 287) and it was applicable for diagnosis of CCA with 55.4% sensitivity, 81.9% specificity, and 76.0% accuracy. A high level of serum BMAG (≥82.5 AU/mL) was associated with unfavorable survival of CCA patients; this information suggested the potential of serum BMAG as a poor prognostic indicator of CCA. In summary, BMAG was aberrantly expressed in preneoplastic bile ducts and CCA, it was also highly detected in patient serum which potentially used as a marker for diagnosis and prognostic prediction of CCA.

LM-GlycomeAtlas Ver. 2.0: An Integrated Visualization for Lectin Microarray-based Mouse Tissue Glycome Mapping Data with Lectin Histochemistry

Laser microdissection-assisted lectin microarray has been used to obtain quantitative and qualitative information on glycans on proteins expressed in microscopic regions of formalin-fixed paraffin-embedded tissue sections. For the effective visualization of this "tissue glycome mapping" data, a novel online tool, LM-GlycomeAtlas (https://glycosmos.org/lm_glycomeatlas/index), was launched in the freely available glycoscience portal, the GlyCosmos Portal (https://glycosmos.org). In LM-GlycomeAtlas Version 1.0, nine tissues from normal mice were used to provide one data set of glycomic profiles. Here we introduce an updated version of LM-GlycomeAtlas, which includes more spatial information. We designed it to deposit multiple data sets of glycomic profiles with high-resolution histological images, which included staining images with multiple lectins on the array. The additionally implemented interfaces allow users to display multiple histological images of interest (e.g., diseased and normal mice), thereby facilitating the evaluation of tissue glycomic profiling and glyco-pathological analysis. Using these updated interfaces, 451 glycomic profiling data and 42 histological images obtained from 14 tissues of normal and diseased mice were successfully visualized. By easy integration with other tools for glycoproteomic data and protein glycosylation machinery, LM-GlycomeAtlas will be one of the most valuable open resources that contribute to both glycoscience and proteomics communities.

Anticancer Activity of Lectins from Bauhinia purpurea and Wisteria floribunda on Breast Cancer MCF-7 Cell Lines

BACKGROUND

Individual and collaborative efforts are being made worldwide in search of effective chemical or natural drugs with less severe side-effects for treatment of cancer. Due to the specificity and selectivity properties of lectins for saccharides, several plant lectins are known to induce cytotoxicity into tumor cells.

OBJECTIVE

To study the antiproliferative activity of two N-acetyl galactosamine specific plant lectins from seeds of Bauhinia purpurea and Wisteria floribunda against MCF-7 Breast cancer cell lines.

METHODS

MTT, lactate dehydrogenase (LDH) leakage, reactive oxygen species (ROS), and caspase- 3 assays and flow cytometry for cell cycle analysis were performed.

RESULTS

The agglutinins BPL and WFL; 446 μgml-1 (2.2 μM) and 329 μgml-1 (2.8 μM), respectively caused remarkable concentration-dependent antiproliferative effect on MCF-7. The effect was seen to be a consequence of binding of the lectin to the cell surface and triggering S and G2 phase arrest. Apoptosis induced was found to be associated with LDH leakage, cell cycle arrest and ROS generation. The apoptotic signal was observed to be amplified by activation of caspase-3 resulting in cell death.

CONCLUSION

The study provides a base for detailed investigation and further use of lectins in cancer studies.

The O-GalNAcylating enzyme GALNT5 mediates carcinogenesis and progression of cholangiocarcinoma via activation of AKT/ERK signaling

Mucin type O-glycosylation is a posttranslational modification of membrane and secretory proteins. Transferring of N-acetylgalactosamine, the first sugar of O-glycosylation, is catalyzed by one of the 20 isoforms of polypeptide N-acetylgalactosaminyltransferases (GALNTs). In this study, Vicia villosa lectin (VVL), a lectin that recognizes O-GalNAcylated glycans, was used to detect VVL-binding glycans (VBGs) in cholangiocarcinoma (CCA). The elevation of VBGs in tumor tissues of the liver fluke associated with CCA from hamsters and patients was noted. VBGs were detected in hyperplastic/dysplastic bile ducts and CCA but not in normal biliary epithelia and hepatocytes, indicating the association of VBGs with CCA development and progression. GALNT5 was shown to be the major isoform found in human CCA cell lines with high VBG expression. Suppression of GALNT5 expression using siRNA significantly reduced VBG expression, signifying the connection of GALNT5 and VBGs observed. Knocked-down GALNT5 expression considerably inhibited proliferation, migration and invasion of CCA cells. Increased expression of GALNT5 using pcDNA3.1-GALNT5 expression vector induced invasive phenotypes in CCA cells with low GALNT5 expression. Increasing of claudin-1 and decreasing of slug and vimentin expression together with inactivation of Akt/Erk signaling were noted in GALNT5 knocked-down cells. These observations were reversed in GALNT5 over-expressing cells. GALNT5-modulated progression of CCA cells was shown to be, in part, via GALNT5-mediated autocrine/paracrine factors that stimulated activations of Akt/Erk signaling and the epithelial to mesenchymal transition process. GALNT5 and its O-GalNAcylated products may have important roles in promoting progression of CCA and could possibly be novel targets for treatment of metastatic CCA.

O-Glycan-Altered Extracellular Vesicles: A Specific Serum Marker Elevated in Pancreatic Cancer

Simple Summary

Pancreatic cancer (PC) is among the most lethal malignancies due to an often delayed and difficult initial diagnosis. Therefore, the development of a novel, early stage, diagnostic PC marker in liquid biopsies is of great significance. In this study, we analyzed the differential glycomic profiling of extracellular vesicles (EVs) derived from serum using lectin microarray. The glyco-candidates of PC-specific EVs were quantified using a high-sensitive exosome-counting system, ExoCounter. An absolute quantification system for altered glycan-containing EVs elevated in PC serum was established. EVs recognized by O-glycan-binding lectins ABA or ACA were identified as candidate markers by lectin microarray. Quantitative analyses using ExoCounter revealed that the ABA- or ACA-positive EVs were significantly increased in the serum of PC patients. These specific EVs with O-glycans can act as potential biomarkers in a liquid biopsy for PC patients screening.

Abstract

Pancreatic cancer (PC) is among the most lethal malignancies due to an often delayed and difficult initial diagnosis. Therefore, the development of a novel, early stage, diagnostic PC marker in liquid biopsies is of great significance. In this study, we analyzed the differential glycomic profiling of extracellular vesicles (EVs) derived from serum (two cohorts including 117 PC patients and 98 normal controls) using lectin microarray. The glyco-candidates of PC-specific EVs were quantified using a high-sensitive exosome-counting system, ExoCounter. An absolute quantification system for altered glycan-containing EVs elevated in PC serum was established. EVs recognized by O-glycan-binding lectins ABA or ACA were identified as candidate markers by lectin microarray. Quantitative analyses using ExoCounter revealed that the ABA- or ACA-positive EVs were significantly increased in the culture of PC cell lines or in the serum of PC patients including carbohydrate antigen 19-9 negative patients with high area under curve values. The elevated numbers of EVs in PC serum returned to normal levels after pancreatectomy. Histological examination confirmed that the tumors stained with ABA/ACA. These specific EVs with O-glycans recognized by ABA/ACA are elevated in PC sera and can act as potential biomarkers in a liquid biopsy for PC patients screening.

Glycogene Expression Profiling of Hepatic Cells by RNA-Seq Analysis for Glyco-Biomarker Identification

Glycans are primarily generated by “glycogenes,” which consist of more than 200 genes for glycosynthesis, including sugar-nucleotide synthases, sugar-nucleotide transporters, and glycosyltransferases. Measuring the expression level of glycogenes is one of the approaches to analyze the glycomes of particular biological and clinical samples. To develop an effective strategy for identifying the glycosylated biomarkers, we performed transcriptome analyses using quantitative real-time polymerase chain reaction (qRT-PCR) arrays and RNA sequencing (RNA-Seq). First, we measured and analyzed the transcriptome from the primary culture of human liver cells and hepatocarcinoma cells using RNA-Seq. This analysis revealed similar but distinctive expression profiles of glycogenes among hepatic cells as indicated by the qRT-PCR arrays, which determined a copy number of 186 glycogenes. Both data sets indicated that altered expression of glycosyltransferases affect the glycosylation of particular glycoproteins, which is consistent with the mass analysis data. Moreover, RNA-Seq analysis can uncover mutations in glycogenes and search differently expressed genes out of more than 50,000 distinct human gene transcripts including candidate biomarkers that were previously reported for hepatocarcinoma cells. Identification of candidate glyco-biomarkers from the expression profile of the glycogenes and proteins from liver cancer tissues available from public database emphasized the possibility that even though the expression level of biomarkers might not be altered, the expression of the glycogenes modifying biomarkers, generating glyco-biomarkers, might be different. Pathway analysis revealed that ~20% of the glycogenes exhibited different expression levels in normal and cancer cells. Thus, transcriptome analyses using both qRT-PCR array and RNA-Seq in combination with glycome and glycoproteome analyses can be advantageous to identify “glyco-biomarkers” by reinforcing information at the expression levels of both glycogenes and proteins.

Multi-serum glycobiomarkers improves the diagnosis and prognostic prediction of cholangiocarcinoma

BACKGROUND

Aberrant glycosylation has been reported to play important roles in progression of cholangiocarcinoma (CCA) and hence the aberrant expressed glycans are beneficial markers for diagnosis and prognostic prediction of CCA.

METHODS

Five CCA-associated glycobiomarkers-carbohydrate antigen 19-9 (CA19-9), carbohydrate antigen-S27 (CA-S27), CCA-associated carbohydrate antigen (CCA-CA), WFA-positive MUC1 (WFA⁺-MUC1), and WFA-positive M2BP (WFA⁺-M2BP), in the sera from CCA patients (N = 138) were determined in comparison with non-CCA control subjects (N = 246).

RESULTS

Receiver operating characteristic analysis suggested the significance of each glycobiomarker in discriminating CCA from non-CCA with area under curve of 0.580-0.777. High levels of CA19-9, CCA-CA, CA-S27, or WFA⁺-MUC1 were associated with poor prognosis and poor survival of CCA patients. Combination of these glycobiomarkers and graded as a GlycoBiomarker (GB)-score could increase the power of the tests in diagnosis than an individual marker with 81% of sensitivity, specificity and accuracy.

CONCLUSIONS

According to the GB-score, these glycobiomarkers not only increased diagnostic power but also discriminated survival of patients indicating the diagnostic and prognostic values of GB-score.

Plant-Derived Lectins as Potential Cancer Therapeutics and Diagnostic Tools

Cancer remains a global health challenge, with high morbidity and mortality, despite the recent advances in diagnosis and treatment. Multiple compounds assessed as novel potential anticancer drugs derive from natural sources, including microorganisms, plants, and animals. Lectins, a group of highly diverse proteins of nonimmune origin with carbohydrate-binding abilities, have been detected in virtually all kingdoms of life. These proteins can interact with free and/or cell surface oligosaccharides and might differentially bind cancer cells, since malignant transformation is tightly associated with altered cell surface glycans. Therefore, lectins could represent a valuable tool for cancer diagnosis and be developed as anticancer therapeutics. Indeed, several plant lectins exert cytotoxic effects mainly by inducing apoptotic and autophagic pathways in malignant cells. This review summarizes the current knowledge regarding the basis for the use of lectins in cancer diagnosis and therapy, providing a few examples of plant-derived carbohydrate-binding proteins with demonstrated antitumor effects.

Discovery of Pancreatic Ductal Adenocarcinoma-Related Aberrant Glycosylations: A Multilateral Approach of Lectin Microarray-Based Tissue Glycomic Profiling With Public Transcriptomic Datasets

Aberrant protein glycosylation is one of the most notable features in cancerous tissues, and thereby glycoproteins with disease-relevant glycosylation alterations are fascinating targets for the development of biomarkers and therapeutic agents. For this purpose, a reliable strategy is needed for the analysis of glycosylation alterations occurring on specific glycoproteins during the progression of cancer. Here, we propose a bilateral approach combining lectin microarray-based tissue glycomic profiling and database-derived transcriptomic datasets. First, lectin microarray was used to perform differential glycomic profiling of crude extracts derived from non-tumor and tumor regions of frozen tissue sections from pancreatic ductal adenocarcinoma (PDAC). This analysis revealed two notable tissue glycome alterations in PDAC samples: increases in sialylated glycans and bisecting N-acetylglucosamine and a decrease in ABO blood group antigens. To examine aberrations in the glycosylation machinery related to these glycomic alterations, we next employed public datasets of gene expression profiles in cancerous and normal pancreases provided by The Cancer Genome Atlas and the Genotype-Tissue Expression projects, respectively. In this analysis, glycosyltransferases responsible for the glycosylation alterations showed aberrant gene expression in the cancerous tissues, consistent with the tissue glycomic profiles. The correlated alterations in glycosyltransferase expression and tissue glycomics were then evaluated by differential glycan profiling of a membrane N-glycoprotein, basigin, expressed in tumor and non-tumor pancreatic cells. The focused differential glycomic profiling for endogenous basigin derived from non-tumor and cancerous regions of PDAC tissue sections demonstrated that PDAC-relevant glycan alterations of basigin closely reflected the notable features in the disease-specific alterations in the tissue glycomes. In conclusion, the present multi-omics strategy using public transcriptomic datasets and experimental glycomic profiling using a tiny amount of clinical specimens successfully demonstrated that basigin is a representative N-glycoprotein that reflects PDAC-related aberrant glycosylations. This study indicates the usefulness of large public data sets such as the gene expression profiles of glycosylation-related genes for evaluation of the highly sensitive tissue glycomic profiling results. This strategy is expected to be useful for the discovery of novel glyco-biomarkers and glyco-therapeutic targets.

Functional glycomics: Application to medical science and hepatology

Glycomics refers to the comprehensive analysis of glycans. Recent progress in glycotechnology enables the determination of a variety of biological functions of glycans. Among different glycosylation patterns, certain types of aberrant glycosylation are linked to cancer and/or inflammation, and thus have biological importance. Glycotechnology has been applied to many fields of medical science, including hepatology. In particular, dramatic changes in glycosylation are observed in the progression of liver diseases. As the liver produces so many serum glycoproteins, changes in glycosylation of these proteins might provide useful disease biomarkers. Furthermore, many patients with genetic diseases of glycosylation who have liver dysfunction have been found as a result from whole genome sequencing, and various kinds of glycotherapy have been developed, especially in immunotherapy. In this review, we describe our basic knowledge of glycobiology and discuss the application of these data to medical science, especially hepatology.

Qualitative and quantitative alterations in intracellular and membrane glycoproteins maintain the balance between cellular senescence and human aging

Glycans are associated with and serve as biomarkers for various biological functions. We previously reported that cell surface sialylated glycoproteins of dermal fibroblasts decreased with cellular senescence and human aging. There is little information on the changes in glycoprotein expression and subcellular localization during the aging process. Here, we examined intracellular glycan profiles of fibroblasts undergoing cellular senescence and those derived from aging human subjects using lectin microarray analysis. We found a sequential change of the intracellular glycan profiles was little during cellular senescence. The intracellular glycans of cells derived from aged fetus and from elderly subjects showed similar localized patterns while repeating unsteady changes. The ratio of α2-3/2-6sialylated intracellular glycoproteins in total cell extracts increased, except for a part of α2-3sialylated O-glycans. These findings are in contrast to those for membrane glycoprotein, which decreased with aging. Interestingly, the ratio of increasing sialylated glycoproteins in the fetus-derived cells showing cellular senescence was similar to that in cells derived from the elderly. Thus, intracellular glycans may maintain cellular functions such as ubiquitin/proteasome-mediated degradation and/or autophagy during aging by contributing to the accumulation of intracellular glycosylated proteins. Our findings provide novel mechanistic insight into the molecular changes that occur during aging.

Quantitative Proteomic Analysis and Evaluation of the Potential Prognostic Biomarkers in Cholangiocarcinoma

Background & Aims: Cholangiocarcinoma (CCA) patients have poor outcomes since the late diagnosis limits the benefits of surgery therapy and curative treatment options. The present study was designed to screen the biomarkers for CCA patients. Methods: Quantitative iTRAQ proteomic analysis was used to identify differentially expressed proteins between CCA and pericarcineous tissue. We examined the expression profile of PRDX2, BGN, LUM, and PPP3CA in CCA tissue using immunohistochemistry. We further investigated the correlation between PPP3CA expression and the survival of CCA patients (n=91). Results: 2,886 confidential proteins were identified by using the iTRAQ technique, 233 of which were differentially expressed. PRDX2, BGN, PPP3CA, and LUM were expressed in CCA tissue, whereas they were not expressed in choledocal cyst tissue except for LUM. PPP3CA was expressed in the cytoplasm of carcinoma cells in 22 cases (24.2%) of 91 CCA patients. Patients with PPP3CA-positive expression showed a significantly shorter survival period than did non-expressing patients (P = 0.030). The univariate analysis showed that tumor size (P = 0.002), vascular invasion (P = 0.001), histological grading (P = 0.011), and PPP3CA expression (P = 0.033) were statistically significant risk factors affecting the prognosis of CCA patients. The multivariate analysis demonstrated PPP3CA expression (P = 0.009) and vascular invasion (P = 0.012) were statistically significant independent risk factors of CCA patients. Conclusions: The results suggested that the expression of PPP3CA in CCA patients is a new independent factor for poor prognosis and a useful prognostic predictor for patients with CCA.

An Improved Method for Cell Type-Selective Glycomic Analysis of Tissue Sections Assisted by Fluorescence Laser Microdissection

Lectin microarray (LMA) is a highly sensitive technology used to obtain the global glycomic profiles of endogenous glycoproteins in biological samples including formalin-fixed paraffin-embedded tissue sections. Here, we describe an effective method for cell type-selective glycomic profiling of tissue fragments collected by laser microdissection (LMD) under fluorescent histochemical visualization. We optimized each step of histochemical staining and confirmed the reliability and validity of glycomic profiling. Using the optimized procedure, glycomic profiles were obtained with 0.5 mm² of stained thymic sections (5-μm-thick) from 8-week-old C57BL/6J male mice. The glycomic profiles of Ulex europaeus agglutinin-I (UEA-I)-stained medullary regions showed higher UEA-I signals than those of the morphologically determined medulla regions, indicating the utility of this method for UEA-I(+) cell-selective analysis. To further evaluate this method, tissue fragments was serially collected from stained and unstained areas of medullary epithelial cell probes (UEA-I and anti-cytokeratin 5 antibody) and a cortex-staining probe (peanut agglutinin). The medullary regions assigned by the three probes showed significantly different glycomic profiles, highlighting the difference in subpopulation recognition among the three probes, which was consistent with previous reports. In conclusion, our fluorescence LMD-LMA method enabled cell type-selective tissue glycomic analysis of pathological specimens and animal models, especially for glyco-biomarker discovery.

Meta-analysis of the diagnostic value of Wisteria floribunda agglutinin-sialylated mucin1 and the prognostic role of mucin1 in human cholangiocarcinoma

OBJECTIVE

Serum carbohydrate antigen 19-9 (CA19-9) is a widely used tumour marker for cholangiocarcinoma (CCA). However, it is not a necessarily good CCA marker in terms of diagnostic accuracy. The purpose of this study is to evaluate the diagnostic value of Wisteria floribundaagglutinin-sialylated Mucin1 (WFA-MUC1) and the prognostic role of Mucin1 (MUC1) in human CCA.

DESIGN

Meta-analysis.

DATA SOURCES

Studies published in PubMed, Web of Science, The Cochrane Library and the China National Knowledge Infrastructure up to 11 October 2017.

ELIGIBILITY CRITERIA

We included reports assessing the diagnostic capacity of WFA-MUC1 and the prognostic role of MUC1 in CCA. The receiver operating characteristic curve (ROC) of WFA-MUC1 and/or CA19-9 was described, and the HRs including 95% CI and the corresponding p value for MUC1 can be extracted.

DATA EXTRACTION AND SYNTHESIS

Two independent researchers extracted data and assessed risk of bias. The diagnostic sensitivity and specificity data of WFA-MUC1 were extracted and analysed as bivariate data. Pooled HRs and its 95% CI for MUC1 were calculated with a random-effects meta-analysis model on overall survival of resectable CCA.

RESULTS

Sixteen reports were included in this study. The pooled sensitivity and specificity of WFA-MUC1 were 0.76 (95% CI 0.71 to 0.81) and 0.72 (95% CI 0.59 to 0.83) in serum, 0.85 (95% CI 0.81 to 0.89) and 0.72 (95% CI 0.64 to 0.80) in bile and 0.72 (95% CI 0.50 to 0.87) and 0.85 (95% CI 0.70 to 0.93) in tissue, respectively. The summary ROC (SROC) were 0.77 (95% CI 0.73 to 0.81) in serum, 0.88 (95% CI 0.85 to 0.90) in bile and 0.86 (95% CI 0.83 to 0.89) in tissue, respectively. Furthermore, the pooled sensitivity and specificity and the SROC of CA19-9 in serum were 0.67 (95% CI 0.61 to 0.72), 0.86 (95% CI 0.75 to 0.93) and 0.75 (95% CI 0.71 to 0.79), respectively. The pooled HRs for MUC1 was 2.20 (95% CI 1.57 to 3.01) in CCA and 4.17 (95% CI 1.71 to 10.17) in mass-forming intrahepatic CCA.

CONCLUSIONS

Compared with CA19-9, WFA-MUC1 was shown to possess stronger diagnostic capability. MUC1 could serve as a prognosis factor for poor outcomes of CCA, particularly, mass-forming intrahepatic CCA.

Glycosylation markers in cancer

Alteration of glycosylation, a hallmark of cancer, results in the production of tumor-associated glycans or glycoproteins. These molecules are subsequently secreted or membrane-shed into the blood stream and thus serve as tumor-associated markers. Increased glycosylation in cancer is triggered by overexpression of glycoproteins that carry certain specific glycans, increase or decrease of nucleotide sugar donors and altered expression of glycosyltransferase and glycosidase enzymes. In this chapter, the biochemistry and function of glycoprotein, glycan and enzyme markers are reviewed. These glycosylation markers, applicable for detection and monitoring of cancer, include CA19-9, CA125, CEA, PSA and AFP. Because of their specific affinity to distinct sugar moieties, lectins are useful for developing assays to detect these tumor associated glycans and glycoproteins in clinical samples. As such, various enzyme-linked lectin assays (ELLA) have been developed for diagnosis, monitoring and prognosis. Because glycosylation changes occur early in cancer, the detection of tumor associated glycosylation markers using lectin based assays is an effective strategy to improve diagnosis and treatment resulting better outcomes clinically.

Current Technologies for Complex Glycoproteomics and Their Applications to Biology/Disease-Driven Glycoproteomics

Glycoproteomics is an important recent advance in the field of glycoscience. In glycomics, glycan structures are comprehensively analyzed after glycans are released from glycoproteins. However, a major limitation of glycomics is the lack of insight into glycoprotein functions. The Biology/Disease-driven Human Proteome Project has a particular focus on biological and medical applications. Glycoproteomics technologies aimed at obtaining a comprehensive understanding of intact glycoproteins, i.e., the kind of glycan structures that are attached to particular amino acids and proteins, have been developed. This Review focuses on the recent progress of the technologies and their applications. First, the methods for large-scale identification of both N- and O-glycosylated proteins are summarized. Next, the progress of analytical methods for intact glycopeptides is outlined. MS/MS-based methods were developed for improving the sensitivity and speed of the mass spectrometer, in parallel with the software for complex spectrum assignment. In addition, a unique approach to identify intact glycopeptides using MS1-based accurate masses is introduced. Finally, as an advance of glycomics, two approaches to provide the spatial distribution of glycans in cells are described, i.e., MS imaging and lectin microarray. These methods allow rapid glycomic profiling of different types of biological samples and thus facilitate glycoproteomics.

Highly Sensitive Glycan Profiling of Hepatitis B Viral Particles and a Simple Method for Dane Particle Enrichment

Hepatitis B virus (HBV) is a double-stranded DNA virus composed of three types of viral particles. The virions are called Dane particles and the others are noninfectious subviral particles (SVPs). In blood, SVPs are detected in abundance, about 1000-10000 fold higher than Dane particles. Dane particles are hazardous because of their strong infectivity, unlike SVPs. Dane particles are covered with an envelope of glycoprotein called HBV surface antigen (HBsAg). HBsAg glycosylation is involved in viral particle formation and secretion. In this study, we established a novel and highly sensitive method for viral glycan profiling of HBsAg using small aliquots of patient serum. Our lectin microarray system could sensitively profile the glycans exposed on HBV while retaining the intact viral particle structure under nonreducing conditions. Several typical lectins were chosen from the lectin microarray results. Specifically, jacalin, which recognizes O-glycan, showed specific and strong reactivity to the M-HBsAg required for Dane particle secretion. Employing the lectin-fractionation method using jacalin, HBV particles were fractionated into jacalin-bound and unbound fractions from patient serum. We measured HBsAg titer and viral DNA load in each fraction using clinical tests. Interestingly, the jacalin-bound fraction contained a major fraction of the HBV viral DNA load. Thus, in this study we have presented a glycan profiling method for HBsAg on the intact HBV particle and an easy and simple method to enrich Dane particles from patient serum by jacalin fractionation.

Serum Wisteria floribunda agglutinin-positive Mac-2 binding protein predicts hepatocellular carcinoma incidence and recurrence in nucleos(t)ide analogue therapy for chronic hepatitis B

BACKGROUND

Hepatocellular carcinoma (HCC) occurs in chronic hepatitis B (CH-B) patients even after treatment with nucleos(t)ide analogues (NAs) by a mechanism involving an association between the oncogenic factors of integrated HBV and liver fibrosis. An association has been demonstrated between advanced chronic liver disease and elevated levels of Wisteria floribunda agglutinin-positive Mac-2 binding protein (WFA(+)-M2BP), a recently discovered serum liver fibrosis marker. Moreover, hepatitis B core-related antigen (HBcrAg) reflects intracellular HBV protein production and its relationship with liver carcinogenesis has been reported. This study aimed to determine whether the incidence and recurrence of HBV-related liver cancer could be predicted using these serum markers.

METHODS

We evaluated 141 CH-B cases treated for more than 1 year with NAs. We compared 17 HCC cases with 124 non-HCC cases and evaluated serum WFA(+)-M2BP, HBV markers including HBcrAg, and other clinical factors. We also evaluated 71 CH-B-related HCC cases who started or continued NAs and compared the incidence and recurrence of HCC after successful cancer treatment.

RESULTS

Multivariate analysis showed that the incidence of HCC was significantly associated with higher histological stage and grade before NA treatment and with WFA(+)-M2BP and HBcrAg positivity during NA treatment. The cumulative incidence of HCC was strongly associated with higher WFA(+)-M2BP levels and HBcrAg positivity. HCC recurrence after anti-cancer therapy was also significantly associated with higher WFA(+)-M2BP levels compared with those in cases without recurrence during follow-up.

CONCLUSION

Serum WFA(+)-M2BP and HBcrAg are useful diagnostic tests for predicting the development and recurrence of HBV-related HCC during NA treatment.

Lectin-Based Assay for Glycoform-Specific Detection of α2,6-sialylated Transferrin and Carcinoembryonic Antigen in Tissue and Body Fluid

Antibodies are useful for detecting glycoprotein antigens, but a conventional antibody recognizes only a protein epitope rather than a glycan. Thus, glycan isoform detection generally requires time- and labor-consuming processes such as lectin affinity column chromatography followed by sandwich ELISA. We recently found antigen-antibody reactions that were inhibited by lectin binding to glycans on the glycoprotein antigen, leading to a convenient glycoform-specific assay. Indeed, Sambucus sieboldiana agglutinin (SSA) lectin, a binder to sialylα2,6galactose residue, inhibited antibody binding to α2,6-sialylated transferrin (Tf) (SSA inhibition). SSA inhibition was not observed with other glycoforms, such as periodate-treated, sialidase-treated and sialidase/galactosidase-treated Tf, suggesting that the assay was glycoform-specific. SSA inhibition was also applicable for visualizing localization of α2,6-sialylated-Tf in a liver section. This is the first immunohistochemical demonstration of glycoform localization in a tissue section. SSA inhibition was utilized for establishing ELISA to quantify α2,6-sialylated carcinoembryonic antigen (CEA), a marker for various cancers. In addition, α2,6-sialylated-CEA was visualized in a colonic adenocarcinoma section by SSA inhibition. The method would further be applicable to a simple and rapid estimation of other α2,6-sialylated glycoproteins and have a potential aid to histopathological diagnosis.

Biomarkers for the Diagnosis of Cholangiocarcinoma: A Systematic Review

Cholangiocarcinoma (CCA), a malignant tumor of the bile duct, is a major public health problem in many Southeast Asian countries, particularly Thailand. The slow progression makes it difficult for early diagnosis and most patients are detected in advanced stages. This study aimed to review all relevant articles related to the biomarkers for the diagnosis of CCA and point out potential biomarkers. A thorough search was performed in PubMed and ScienceDirect for CCA biomarker articles. Required data were extracted. A total of 46 articles that fulfilled the inclusion and had none of the exclusion criteria were included in the analysis (17, 22, 3, 4, and 1 articles on blood, tissue, bile, both blood and tissue, and urine biomarkers, respectively). Carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA), either alone or in combination with other biomarkers, are the most commonly studied biomarkers in the serum. Their sensitivity and specificity ranged from 47.2% to 98.2% and 89.7% to 100%, respectively. However, in the tissue, gene methylations and DNA-related markers were the most studied CCA biomarkers. Their sensitivity and specificity ranged from 58% to 87% and 98% to 100%, respectively. Some articles investigated biomarkers both in blood and tissues, particularly CA19-9 and CEA, with sensitivity and specificity ranging from 33% to 100% and 50% to 97.7%, respectively. Although quite a number of biomarkers with a potential role in the early detection of CCA have been established, it is difficult to single out any particular marker that could be used in the routine clinical settings.

Clinical significance of GalNAcylated glycans in cholangiocarcinoma: Values for diagnosis and prognosis

Cancer cells exhibited the aberrant cancer-associated glycans that are potential biomarkers for diagnosis and monitoring of the cancer. In this study, Sophora japonica agglutinin (SJA) was used to detect SJA-specific N-acetylgalactosamine-associated glycans (SNAG) in liver tissues and sera from cholangiocarcinoma (CCA) patients. Whether SNAG could be the diagnostic and prognostic markers for CCA was evaluated. SJA-histochemistry revealed that SNAG was undetec2 in normal bile ducts but was highly expressed in hyperplastic/dysplastic bile ducts and CCA. SNAG was negative in hepatocytes and hepatoma tissues indicating SNAG as a differential marker of CCA and hepatoma. SJA-histochemistry of CCA hamster tissues revealed the involvement of SNAG in the early pathogenesis of bile duct epithelia and CCA development. A SJA-based ELISA was successfully developed to determine SNAG in serum. Serum-SNAG from CCA patients was significantly higher than those of non-CCA control groups with the diagnostic values of 59.5% sensitivity and 73.6% specificity, comparable to those of serum CA19-9. High levels of serum SNAG (≥69AU/ml) indicated poor survival of CCA patients. Taken together, SNAG was first demonstrated here to be a glycobiomarker for diagnosis and prognosis of CCA. Association of SNAG with pathogenesis of bile ducts and CCA development were suggested. (198).

Assessment of tumor characteristics based on glycoform analysis of membrane-tethered MUC1

Clinical tissue specimens are useful for pathological diagnosis, which is, in some cases, supported by visualization of biomolecule localization. In general, diagnostic specificity in molecular pathology is increased by the acquisition of a probe to distinguish the modification of isomers. Although glycosylation is one of the candidate modifications in a protein, comparative glycan analysis of disease-associated proteins derived from a single tissue section is still challenging because of the lack of analytical sensitivity. Here we demonstrate a possible method for differential glycoform analysis of an endogenous tumor-associated glycoprotein MUC1 by an antibody-overlay lectin microarray. Tissue sections (5 μm thick) of patients with cholangiocarcinoma (CCA; n=21) and pancreatic ductal adenocarcinoma (PDAC; n=50) were stained with an anti-MUC1 antibody MY.1E12 that was established as a monoclonal antibody recognizing an MUC1 glycosylation isoform with a sialyl-core 1 structure (NeuAcα2-3galactosyl β1-3-N-acetylgalactosamine). MY.1E12-positive tissue areas (2.5 mm2) were selectively dissected with a laser capture microdissection procedure. The membrane MUC1 was enriched by immunoprecipitation with MY.1E12 and subjected to lectin microarray analysis. Even though the reactivities of MY.1E12 between CCA and PDAC were similar, the lectin-binding patterns varied. We found Maackia amurensis leukoagglutinin and pokeweed lectin distinguished MY.1E12-reactive MUC1 of CCA from that of PDAC. Moreover, MUC1 with M. amurensis hemagglutinin (MAH) reactivity potentially reflected the degree of malignancy. These results were confirmed with MAH-MY.1E12 double fluorescent immunostaining. These glycan changes on MUC1 were detected with high sensitivity owing to the cluster effect of immobilized lectins on a tandem repeat peptide antigen covered with highly dense glycosylation such as mucin. Our approach provides the information to investigate novel glycodynamics in biology, for example, glycoalteration, as well as diseases related to not only MUC1 but also other membrane proteins.

Engineering of recombinant Wisteria floribunda agglutinin specifically binding to GalNAcβ1,4GlcNAc (LacdiNAc)

Wisteria floribunda agglutinin (WFA) is a useful probe for distinguishing glycan structural alterations in diseases such as intrahepatic bile duct carcinoma and hepatic fibrosis; however, the gene encoding WFA has not been identified. Here, we identified the gene encoding WFA, and recombinant WFA (rWFA) was expressed in Escherichia coli and purified. The natural complementary DNA sequence obtained from wisteria seeds contained an open reading frame of 861 nucleotides encoding a WFA precursor, which included a hydrophobic signal peptide at the N-terminus, a propeptide at the C-terminus and a single cysteine (Cys) residue for dimer formation. We characterized the natural and rWFA by the glycoconjugate microarray and frontal affinity chromatography. rWFA exhibited glycan binding specificity similar to that of natural WFA: both bound to Gal- and N-acetylgalactosamine (GalNAc)-terminated glycans. Moreover, the engineered WFA with an amino acid substitution in Cys-272 yielded a recombinant monomeric lectin with limited binding specificity but wild-type affinity for GalNAc-terminated glycans, specifically GalNAcβ1,4GlcNAc. Thus, this engineered lectin may be applied to highly sensitive biomarker detection.

Serum Wisteria Floribunda Agglutinin-Positive Sialylated Mucin 1 as a Marker of Progenitor/Biliary Features in Hepatocellular Carcinoma

Histological molecular classification of hepatocellular carcinoma (HCC) is clinically important for predicting the prognosis. However, a reliable serum marker has not been established. The aim of this study was to evaluate the diagnostic value of serum Wisteria Floribunda agglutinin-positive sialylated mucin 1 (WFA-sialylated MUC1), which is a novel biliary marker, as a marker of HCC with hepatic progenitor cell (HPC)/biliary features and of prognosis. A total of 144 consecutive patients who underwent complete radiofrequency ablation of primary HCC were enrolled. A serum WFA-sialylated MUC1 level of 900 μL/mL was determined as the optimal cutoff value for prediction of immunohistochemical staining for HPC/biliary features [sialylated MUC1 and cytokeratin 19 (CK19)]. Positive staining rate of sialylated MUC1 and CK19 was significantly higher in patients with WFA-sialylated MUC1 ≥900 than those with WFA-sialylated MUC1 <900. Furthermore, cumulative incidence of HCC recurrence was significantly higher in patients with WFA-sialylated MUC1 ≥900 and on multivariate analysis, serum WFA-sialylated MUC1 levels was an independent predictor of HCC recurrence. These results revealed that serum WFA-sialylated MUC1 was associated with histological feature of HCC and recurrence after curative therapy and it could be a novel marker of HPC/biliary features in HCC and of prognosis.

A standardized method for lectin microarray-based tissue glycome mapping

The significance of glycomic profiling has been highlighted by recent findings that structural changes of glycans are observed in many diseases, including cancer. Therefore, glycomic profiling of the whole body (glycome mapping) under different physiopathological states may contribute to the discovery of reliable biomarkers with disease-specific alterations. To achieve this, standardization of high-throughput and in-depth analysis of tissue glycome mapping is needed. However, this is a great challenge due to the lack of analytical methodology for glycans on small amounts of endogenous glycoproteins. Here, we established a standardized method of lectin-assisted tissue glycome mapping. Formalin-fixed, paraffin-embedded tissue sections were prepared from brain, liver, kidney, spleen, and testis of two C57BL/6J mice. In total, 190 size-adjusted fragments with different morphology were serially collected from each tissue by laser microdissection and subjected to lectin microarray analysis. The results and subsequent histochemical analysis with selected lectins were highly consistent with previous reports of mass spectrometry-based N- and/or O-glycome analyses and histochemistry. This is the first report to look at both N- and O-glycome profiles of various regions within tissue sections of five different organs. This simple and reproducible mapping approach is also applicable to various disease model mice to facilitate disease-related biomarker discovery.

Intrahepatic cholangiocarcinoma: Molecular markers for diagnosis and prognosis

Intrahepatic cholangiocarcinoma (iCCA) is the second most common primary liver tumor with increasing incidence worldwide. The outcome of patients with iCCA is dismal owing to tumor's aggressiveness, late diagnosis and lack of effective treatment options. Detection of the tumor at early stages may make surgical resection, as only potential curative treatment, more feasible. Unfortunately, despite recent developments in imaging modalities and laboratory tests, the diagnosis of iCCA remains challenging and patients often present in advanced stages when surgery cannot be offered. Moreover, accurate assessment of disease burden is critical to optimize management strategy, including the use of adjuvant therapies and clinical trials. Identifying iCCA specific diagnostic and prognostic biomarkers has been a focus of interest among many investigators with a progressive increase in data on iCCA related to advances in "omics" technologies. We herein summarize iCCA biomarkers and define the molecular mechanisms underlying iCCA carcinogenesis, as well as highlight potential diagnostic and prognostic application of molecular biomarkers.

Polyporus squamosus Lectin 1a (PSL1a) Exhibits Cytotoxicity in Mammalian Cells by Disruption of Focal Adhesions, Inhibition of Protein Synthesis and Induction of Apoptosis

PSL1a is a lectin from the mushroom Polyporus squamosus that binds to sialylated glycans and glycoconjugates with high specificity and selectivity. In addition to its N-terminal carbohydrate-binding domain, PSL1a possesses a Ca²⁺-dependent proteolytic activity in the C-terminal domain. In the present study, we demonstrate that PSL1a has cytotoxic effects on mammalian cancer cells, and we show that the cytotoxicity is dependent on the cysteine protease activity. PSL1a treatment leads to cell rounding and detachment from the substratum, concomitant with disruption of vinculin complexes in focal adhesions. We also demonstrate that PSL1a inhibits protein synthesis and induces apoptosis in HeLa cells, in a time- and concentration-dependent manner.

Wisteria floribunda agglutinin-sialylated mucin core polypeptide 1 is a sensitive biomarker for biliary tract carcinoma and intrahepatic cholangiocarcinoma: a multicenter study

BACKGROUND

Wisteria floribunda agglutinin (WFA)-sialylated mucin core polypeptide 1 (MUC1) was investigated as a new glycoprotein marker for cholangiocarcinoma (CC) using glycoproteomics technologies. In this multicenter study, WFA-sialylated MUC1 levels in serum and bile samples were measured to determine their diagnostic capability in biliary tract carcinoma (BTC) and intrahepatic (Ih) CC.

METHODS

The study included 244 patients with BTC, 59 patients with IhCC, 287 patients with benign biliary tract diseases, and 44 control subjects.

RESULTS

Serum WFA-sialylated MUC1 levels were significantly higher in patients with either BTC or IhCC than in control subjects and those with benign biliary tract diseases. Patients with IhCC showed higher WFA-sialylated MUC1 levels than patients with tumors at other sites. No significant differences in WFA-sialylated MUC1 levels were found with regard to cancer stage or tissue type. Receiver operating characteristic curve analysis showed that WFA-sialylated MUC1 was superior to carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA) for the diagnosis of benign biliary tract diseases, BTC, and IhCC, as well as for stage I and II carcinomas. Significantly higher levels of biliary WFA-sialylated MUC1 were observed in BTC/IhCC than in benign biliary tract diseases. The diagnostic capability of biliary WFA-sialylated MUC1 was also superior to that of CA19-9, and diagnostic sensitivity was higher than that of biliary cytology for BTC/IhCC.

CONCLUSIONS

WFA-sialylated MUC1 is a useful novel biomarker for BTC/IhCC. In the future, this measurement should be applied in the clinical setting.

Molecular Basis for Recognition of the Cancer Glycobiomarker, LacdiNAc (GalNAc[β1→4]GlcNAc), by Wisteria floribunda Agglutinin

Aberrant glycosylation and the overexpression of specific carbohydrate epitopes is a hallmark of many cancers, and tumor-associated oligosaccharides are actively investigated as targets for immunotherapy and diagnostics. Wisteria floribunda agglutinin (WFA) is a legume lectin that recognizes terminal N-acetylgalactosaminides with high affinity. WFA preferentially binds the disaccharide LacdiNAc (β-d-GalNAc-[1→4]-d-GlcNAc), which is associated with tumor malignancy in leukemia, prostate, pancreatic, ovarian, and liver cancers and has shown promise in cancer glycobiomarker detection. The mechanism of specificity for WFA recognition of LacdiNAc is not fully understood. To address this problem, we have determined affinities and structure of WFA in complex with GalNAc and LacdiNAc. Affinities toward Gal, GalNAc, and LacdiNAc were measured via surface plasmon resonance, yielding K_D values of 4.67 × 10^-4 m, 9.24 × 10^-5 m, and 5.45 × 10^-6 m, respectively. Structures of WFA in complex with LacdiNAc and GalNAc have been determined to 1.80-2.32 Å resolution. These high resolution structures revealed a hydrophobic groove complementary to the GalNAc and, to a minor extent, to the back-face of the GlcNAc sugar ring. Remarkably, the contribution of this small hydrophobic surface significantly increases the observed affinity for LacdiNAc over GalNAc. Tandem MS sequencing confirmed the presence of two isolectin forms in commercially available WFA differing only in the identities of two amino acids. Finally, the WFA carbohydrate binding site is similar to a homologous lectin isolated from Vatairea macrocarpa in complex with GalNAc, which, unlike WFA, binds not only αGalNAc but also terminal Ser/Thr O-linked αGalNAc (Tn antigen).

Lectin microarray technology identifies specific lectins related to lymph node metastasis of advanced gastric cancer

BACKGROUND

Although various molecular profiling technologies have the potential to predict specific tumor phenotypes, the comprehensive profiling of lectin-bound glycans in human cancer tissues has not yet been achieved.

METHODS

We examined 242 advanced gastric cancer (AGC) patients without or with lymph node metastasis-N0 (n = 62) or N+ (n = 180)-by lectin microarray, and identified the specific lectins highly associated with AGC phenotypes.

RESULTS

In seven gastric cancer cell lines, in contrast to expressed-in-cancer lectins, not-expressed-in-cancer (NEC) lectins were tentatively designated by lectin microarray. Binding signals of the specific lectins were robustly reduced in AGC patients with N+ status as compared with those with N0 status. The receiver operating characteristic curve determined the optimal cutoff value to differentiate N0 status from N+ status, and subsequent profiling of NEC lectins identified Vicia villosa agglutinin (VVA) association with the significant other lectins involved in lymph node metastasis. VVA reaction was clearly found on cancer cells, suggesting that it may result from carcinoma-stroma interaction in primary AGC, because VVA is an NEC lectin. Most intriguingly, VVA reaction was remarkably attenuated in the tumor cells of the metastatic lymph nodes, even if it was recognized in primary AGC. In AGC, histological type was strongly associated with soybean agglutinin and Bauhinia purpurea lectin, whereas p53 mutation was the best correlated with Griffonia simplicifolia lectin II.

CONCLUSIONS

Lectin microarrays can be used to very accurately quantify the reaction of glycans with tumor tissues, and such profiles may represent the specific phenotypes, including N+ status, histological type, or p53 mutation of AGC.

Clinicopathological characteristics and diagnostic performance of Wisteria floribunda agglutinin positive Mac-2-binding protein as a preoperative serum marker of liver fibrosis in hepatocellular carcinoma

BACKGROUND

Wisteria floribunda agglutinin positive Mac-2-binding protein (WFA(+)-M2BP) is a novel serum marker of liver fibrosis identified in glycoproteomic biomarker screening studies, and its clinicopathological characteristics have yet to be elucidated sufficiently for clinical utilization.

METHODS

We retrospectively analyzed the clinicopathology data and serum WFA(+)-M2BP levels in 376 hepatocellular carcinoma patients undergoing liver surgery. WFA(+)-M2BP was quantified in frozen serum samples collected at the time of surgery using the FastLec-Hepa method.

RESULTS

Significant independent determinants of serum WFA(+)-M2BP levels included pathological diagnosis of cirrhosis, female gender, hepatitis C virus (HCV) infection, and liver dysfunction characteristics, such as abnormal indocyanine green retention rate at 15 min, platelet counts, albumin levels, alanine aminotransferase levels, and total bilirubin levels. Serum WFA(+)-M2BP levels increased with the pathological fibrosis stage and liver dysfunction severity. HCV infection significantly affected serum WFA(+)-M2BP levels throughout the pathological and functional progression of liver fibrosis, and the effect of gender was significant only in F4 stage patients with severe liver dysfunction. The diagnostic thresholds for cutoff index values for cirrhosis were 1.435 and 4.615 in HCV-negative and HCV-positive patients, respectively. Serum WFA(+)-M2BP levels at the time of operation were a significant predictor of hepatocellular carcinoma recurrence and overall survival in both HCV-negative and HCV-positive patients.

CONCLUSIONS

Serum WFA(+)-M2BP levels reflected both the pathological and functional progression of liver fibrosis comprehensively and continuously. Elevated WFA(+)-M2BP levels were a significant risk factor for tumor recurrence and decreased overall survival after liver surgery independent of HCV infection.

A novel glycobiomarker, Wisteria floribunda agglutinin macrophage colony-stimulating factor receptor, for predicting carcinogenesis of liver cirrhosis

Recently, we identified a novel liver fibrosis glycobiomarker, Wisteria floribunda agglutinin (WFA)-reactive colony stimulating factor 1 receptor (WFA(+) -CSF1R), using a glycoproteomics-based strategy. The aim of this study was to assess the value of measuring WFA(+) -CSF1R levels for the prognosis of carcinogenesis and outcome in liver cirrhosis (LC) patients with hepatitis C virus (HCV). WFA(+) -CSF1R and Total-CSF1R levels were measured in serum samples from 214 consecutive HCV-infected patients to evaluate their impact on carcinogenesis and the survival of LC patients. Serum WFA(+) -CSF1R levels were significantly higher in LC patients than chronic hepatitis (CH) patients (p < 0.001). The AUC of WFA(+) -CSF1R for predicting overall survival, calculated by time-dependent ROC analysis, was 0.691 and the HR (per 1-SD increase) was 1.80 (95% CI, 1.23-2.62, p < 0.001). Furthermore, the survival rate of LC patients with high WFA(+) -CSF1R levels (≥ 310 ng/ml) was significantly worse than those with lower levels (p < 0.01). The AUC of WFA(+) /total-CSF1R percentage (WFA(+) -CSF1R%) for predicting the cumulative carcinogenesis rate was 0.760, with an HR of 1.66 (95% CI 1.26-2.20, p < 0.001). In fact, the carcinogenesis rate was significantly higher in LC patients with a high WFA(+) -CSF1R% (≥ 35%, p = 0.006). Assessing serum levels of WFA(+) -CSF1R has diagnostic value for predicting carcinogenesis and the survival of LC patients.