Diverse monoclonal antibodies against the CA 19-9 antigen show variation in binding specificity with consequences for clinical interpretation

Fast NMR-Based Assessment of Cancer-Associated Protein Glycosylations from Serum Samples

Nuclear magnetic resonance (NMR) spectra of blood serum and plasma show signals arising from metabolites, lipoproteins, and N-acetyl methyl groups of N-glycans covalently linked to acute-phase proteins. These glycan signals often called glycoprotein A (GlycA) and glycoprotein B (GlycB) arise from N-acetyl methyl groups and have been proposed as biomarkers, initially for cardiovascular diseases, but also for other inflammatory conditions. For the detection of glycan resonances, J-edited, diffusion, and relaxation filtered NMR spectroscopy (JEDI) has been proposed to suppress the lipoprotein signals. JEDI is however limited to measure those acetyl signals, whereas all other glycan resonance cannot be observed. For improved glycoprotein profiling, the signals arising from the pyranose ring protons are essential. Here, we show how selective frequency excitation combined with scalar coupling filtering can be used to dramatically increase the number of N-glycan signals observable in NMR spectra of serum and plasma samples, facilitating glycosylation profiling in less than 30 min. This approach grants selective detection of sialylation, galactosylation, N-acetylglucosaminylation, and fucosylation of dominant N-glycans and, to some extent, N-glycan branching complexity. Notably, sialylated and nonsialylated Lewisx and Lewisa antigens can also be observed. Lewisa antigen is well established as a cancer biomarker, known as CA19-9. NMR glycosylation profiles from nine isolated serum glycoproteins show excellent agreement with well-established UHPLC-MS analysis. The proposed NMR method facilitates the detection of glycoprotein biomarkers without the need for enzymatic treatment of serum or plasma and provides a robust read-out as exemplified by samples from 33 patients with hepatocellular carcinoma.

Multiplexed glycan immunofluorescence identification of pancreatic cancer cell subpopulations in both tumor and blood samples

Pancreatic ductal adenocarcinoma (PDAC) tumor heterogeneity impedes the development of biomarker assays for early disease detection. We hypothesized that PDAC cell subpopulations could be identified by aberrant glycan signatures in both tumor tissue and blood samples. We used multiplexed glycan immunofluorescence to distinguish between PDAC and noncancer cell subpopulations within tumor tissue, and we developed hybrid glycan sandwich assays to determine whether the aberrant glycan signatures could be detected in blood samples. We found that PDAC cells were identified by signatures of glycans detected by four glycan-binding proteins (VVL, CA19-9, sTRA, and GM2) and that there are three types of glycan-defined PDAC tumors: sTRA type, CA19-9 type, and intermixed. In patient-matched tumor and blood samples, the PDAC tumor type could be determined by the aberrant glycans in the blood. As a result, the combined assays of aberrant glycan signatures were more sensitive and specific than any individual assay. Our results demonstrate a methodology to detect and stratify PDAC.

Circulating Biomarkers of Thyroid Cancer: An Appraisal

Thyroid cancer is the most prevalent endocrine cancer. The prognosis depends on the type and stage at diagnosis. Thyroid cancer treatments involve surgery, possibly followed by additional therapeutic options such as hormone therapy, radiation therapy, targeted therapy and chemotherapy. Besides the well-known thyroid tumor biomarkers, new circulating biomarkers are now emerging. Advances in genomic, transcriptomic and proteomic technologies have allowed the development of novel tumor biomarkers. This review explores the current literature data to critically analyze the benefits and limitations of routinely measured circulating biomarkers for the diagnosis and monitoring of thyroid cancer. The review also sheds light on new circulating biomarkers, focusing on the challenges of their use in the clinical management of thyroid cancer, underlining the need for the identification of a new generation of circulating biomarkers.

Glycosylation in cancer as a source of biomarkers

INTRODUCTION

Glycosylation, the process of glycan synthesis and attachment to target molecules, is a crucial and common post-translational modification (PTM) in mammalian cells. It affects the protein's hydrophilicity, charge, solubility, structure, localization, function, and protection from proteolysis. Aberrant glycosylation in proteins can reveal new detection and therapeutic Glyco-biomarkers, which help to improve accurate early diagnosis and personalized treatment. This review underscores the pivotal role of glycans and glycoproteins as a source of biomarkers in human diseases, particularly cancer.

AREAS COVERED

This review delves into the implications of glycosylation, shedding light on its intricate roles in cancer-related cellular processes influencing biomarkers. It is underpinned by a thorough examination of literature up to June 2024 in PubMed, Scopus, and Google Scholar; concentrating on the terms: (Glycosylation[Title/Abstract]) OR (Glycan[Title/Abstract]) OR (glycoproteomics[Title/Abstract]) OR (Proteoglycans[Title/Abstract]) OR (Glycomarkers[Title/Abstract]) AND (Cancer[Title/Abstract]) AND ((Diagno*[Title/Abstract]) OR (Progno*[Title/Abstract])).

EXPERT OPINION

Glyco-biomarkers enhance early cancer detection, allow early intervention, and improve patient prognoses. However, the abundance and complex dynamic glycan structure may make their scientific and clinical application difficult. This exploration of glycosylation signatures in cancer biomarkers can provide a detailed view of cancer etiology and instill hope in the potential of glycosylation to revolutionize cancer research.

Longitudinal evaluation of external quality assessment results for CA 15-3, CA 19-9, and CA 125

Background

Tumor markers are established laboratory tools that help to diagnose, estimate prognosis, and monitor the course of cancer. For meaningful decision-making in patient care, it is essential that methods and analytical platforms demonstrate high sensitivity, specificity, precision, and comparability. Regular participation at external quality assessment (EQA) schemes is mandatory for laboratories. Here, a longitudinal evaluation of EQA data was performed to assess the performance of tumor marker assays over time.

Methods

Longitudinal data of the cancer antigens (CA) 15-3 (n = 5,492), CA 19-9 (n = 6,802), and CA 125 (n = 5,362) from 14 INSTAND EQAs conducted between 2019 and 2023 were evaluated. A median of 197, 244 and 191 laboratories participated at the EQAs for CA 15-3, CA 19-9 and CA 125, respectively. Data evaluation encompasses intra- and inter-manufacturer specific variations over time, assay precision, and adherence to the EQA limits of ±24% for CA 15-3, ±27% for CA 19-9 and ±36% for CA 125.

Results

The study showed median manufacturer-dependent differences of up to 107% for CA 15-3, 99% for CA 125, and even 549% for CA 19-9 between the highest and the lowest methods over the studied period. Regarding the normalized median of all methods, the values of the most deviant methods were 0.42 for CA 15-3, 7.61 for CA 19-9, and 1.82 for CA 125. Intra-manufacturer variability was generally low, with median coefficients of variation (CV) below 10%. As the methods were evaluated according to method-specific consensus values, most participants passed the EQAs within the acceptance criteria. When the criteria were consistently set at 24%, the central 90% of participants passed the EQAs in 78.6%-100% for CA 15-3 (with exception of AX), 89.3%-100% for CA 125, and 64.3%-100% for CA 19-9.

Conclusion

While intra-method precision of most analytical platforms is acceptable for all three tumor markers, considerable inter-method variability was observed over the whole studied period demonstrating the necessity for better standardization and harmonization of the methods, development of international reference materials, and comprehensive commutability studies with patient samples.

Potential clinical applications of extracellular vesicles in pancreatic cancer: exploring untapped opportunities from biomarkers to novel therapeutic approaches

Pancreatic cancer is a highly lethal and metastatic malignancy, mainly because it often remains undetected until advanced stages due to the limitations of current diagnostic methods, rendering currently available therapies ineffective. Therefore, it is imperative to identify useful biomarkers for early diagnosis and new therapeutic targets for pancreatic cancer. Recently, extracellular vesicles have emerged as promising biomarkers for the diagnosis and prognosis of pancreatic cancer. Given their presence in various bodily fluids, extracellular vesicles offer a non-invasive approach through liquid biopsy to detect and monitor cancer progression. In this review, we comprehensively examine the multifaceted roles of extracellular vesicles in the progression of cancer, while also exploring their potential as diagnostic, prognostic, and therapeutic biomarkers in the context of pancreatic cancer.

Glycan-specific molecularly imprinted polymers towards cancer diagnostics: merits, applications, and future perspectives

Aberrant glycans are a hallmark of cancer states. Notably, emerging evidence has demonstrated that the diagnosis of cancers with tumour-specific glycan patterns holds great potential to address unmet medical needs, especially in improving diagnostic sensitivity and selectivity. However, despite vast glycans having been identified as potent markers, glycan-based diagnostic methods remain largely limited in clinical practice. There are several reasons that prevent them from reaching the market, and the lack of anti-glycan antibodies is one of the most challenging hurdles. With the increasing need for accelerating the translational process, numerous efforts have been made to find antibody alternatives, such as lectins, boronic acids and aptamers. However, issues concerning affinity, selectivity, stability and versatility are yet to be fully addressed. Molecularly imprinted polymers (MIPs), synthetic antibody mimics with tailored cavities for target molecules, hold the potential to revolutionize this dismal progress. MIPs can bind a wide range of glycan markers, even those without specific antibodies. This capacity effectively broadens the clinical applicability of glycan-based diagnostics. Additionally, glycoform-resolved diagnosis can also be achieved through customization of MIPs, allowing for more precise diagnostic applications. In this review, we intent to introduce the current status of glycans as potential biomarkers and critically evaluate the challenges that hinder the development of in vitro diagnostic assays, with a particular focus on glycan-specific recognition entities. Moreover, we highlight the key role of MIPs in this area and provide examples of their successful use. Finally, we conclude the review with the remaining challenges, future outlook, and emerging opportunities.

Aberrant Glycosylation as Immune Therapeutic Targets for Solid Tumors

Glycosylation occurs at all major types of biomolecules, including proteins, lipids, and RNAs to form glycoproteins, glycolipids, and glycoRNAs in mammalian cells, respectively. The carbohydrate moiety, known as glycans on glycoproteins and glycolipids, is diverse in their compositions and structures. Normal cells have their unique array of glycans or glycome which play pivotal roles in many biological processes. The glycan structures in cancer cells, however, are often altered, some having unique structures which are termed as tumor-associated carbohydrate antigens (TACAs). TACAs as tumor biomarkers are glycan epitopes themselves, or glycoconjugates. Some of those TACAs serve as tumor glyco-biomarkers in clinical practice, while others are the immune therapeutic targets for treatment of cancers. A monoclonal antibody (mAb) to GD2, an intermediate of sialic-acid containing glycosphingolipids, is an example of FDA-approved immune therapy for neuroblastoma indication in young adults and many others. Strategies for targeting the aberrant glycans are currently under development, and some have proceeded to clinical trials. In this review, we summarize the currently established and most promising aberrant glycosylation as therapeutic targets for solid tumors.

The next "sweet" spot for pancreatic ductal adenocarcinoma: Glycoprotein for early detection

Pancreatic ductal adenocarcinoma (PDAC) is the most common neoplastic disease of the pancreas, accounting for more than 90% of all pancreatic malignancies. As a highly lethal malignancy, PDAC is the fourth leading cause of cancer-related deaths worldwide with a 5-year overall survival of less than 8%. The efficacy and outcome of PDAC treatment largely depend on the stage of disease at the time of diagnosis. Surgical resection followed by adjuvant chemotherapy remains the only possibly curative therapy, yet 80%-90% of PDAC patients present with nonresectable PDAC stages at the time of clinical presentation. Despite our advancing knowledge of PDAC, the prognosis remains strikingly poor, which is primarily due to the difficulty of diagnosing PDAC at the early stages. Recent advances in glycoproteomics and glycomics based on mass spectrometry have shown that aberrations in protein glycosylation plays a critical role in carcinogenesis, tumor progression, metastasis, chemoresistance, and immuno-response of PDAC and other types of cancers. A growing interest has thus been placed upon protein glycosylation as a potential early detection biomarker for PDAC. We herein take stock of the advancements in the early detection of PDAC that were carried out with mass spectrometry, with special focus on protein glycosylation.

MicroRNA-125a-3p, -4530, and -92a as a Potential Circulating MicroRNA Panel for Noninvasive Pancreatic Cancer Diagnosis

MicroRNA (miRNA) expression dysregulations in pancreatic ductal adenocarcinoma (PDAC) have been studied widely for their diagnostic and prognostic utility. By the use of bioinformatics-based methods, in our previous study, we identified some potential miRNA panels for diagnosis of pancreatic cancer patients from noncancerous controls (the screening stage). In this report, we used 142 plasma samples from people with and without pancreatic cancer (PC) to conduct RT-qPCR differential expression analysis to assess the strength of the first previously proposed diagnostic panel (consisting of miR-125a-3p, miR-4530, and miR-92a-2-5p). As the result, we identified significant upregulation for all the three considered miRNAs in the serum of PC patients. After that, a three-miRNA panel in serum was developed. The area under the receiver operating characteristic curves (AUC) for the panel were 0.850, 0.910, and 0.86, respectively, indicating that it had a higher diagnostic value than individual miRNAs. Therefore, we detected a promising three-miRNA panel in the plasma for noninvasive PC diagnosis (miR-125a-3p, miR-4530, and miR-92a-2-5p).

Role of tumor cell sialylation in pancreatic cancer progression

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest malignancies and is currently the third leading cause of cancer death. The aggressiveness of PDAC stems from late diagnosis, early metastasis, and poor efficacy of current chemotherapies. Thus, there is an urgent need for effective biomarkers for early detection of PDAC and development of new therapeutic strategies. It has long been known that cellular glycosylation is dysregulated in pancreatic cancer cells, however, tumor-associated glycans and their cognate glycosylating enzymes have received insufficient attention as potential clinical targets. Aberrant glycosylation affects a broad range of pathways that underpin tumor initiation, metastatic progression, and resistance to cancer treatment. One of the prevalent alterations in the cancer glycome is an enrichment in a select group of sialylated glycans including sialylated, branched N-glycans, sialyl Lewis antigens, and sialylated forms of truncated O-glycans such as the sialyl Tn antigen. These modifications affect the activity of numerous cell surface receptors, which collectively impart malignant characteristics typified by enhanced cell proliferation, migration, invasion and apoptosis-resistance. Additionally, sialic acids on tumor cells engage inhibitory Siglec receptors on immune cells to dampen anti-tumor immunity, further promoting cancer progression. The goal of this review is to summarize the predominant changes in sialylation occurring in pancreatic cancer, the biological functions of sialylated glycoproteins in cancer pathogenesis, and the emerging strategies for targeting sialoglycans and Siglec receptors in cancer therapeutics.

Anti-glycan antibodies: roles in human disease

Carbohydrate-binding antibodies play diverse and critical roles in human health. Endogenous carbohydrate-binding antibodies that recognize bacterial, fungal, and other microbial carbohydrates prevent systemic infections and help maintain microbiome homeostasis. Anti-glycan antibodies can have both beneficial and detrimental effects. For example, alloantibodies to ABO blood group carbohydrates can help reduce the spread of some infectious diseases, but they also impose limitations for blood transfusions. Antibodies that recognize self-glycans can contribute to autoimmune diseases, such as Guillain-Barre syndrome. In addition to endogenous antibodies that arise through natural processes, a variety of vaccines induce anti-glycan antibodies as a primary mechanism of protection. Some examples of approved carbohydrate-based vaccines that have had a major impact on human health are against pneumococcus, Haemophilus influeanza type b, and Neisseria meningitidis. Monoclonal antibodies specifically targeting pathogen associated or tumor associated carbohydrate antigens (TACAs) are used clinically for both diagnostic and therapeutic purposes. This review aims to highlight some of the well-studied and critically important applications of anti-carbohydrate antibodies.

Roles of CA19-9 in pancreatic cancer: Biomarker, predictor and promoter

Carbohydrate antigen 19-9 (CA19-9) is the best validated biomarker and an indicator of aberrant glycosylation in pancreatic cancer. CA19-9 functions as a biomarker, predictor, and promoter in pancreatic cancer. As a biomarker, the sensitivity is approximately 80%, and the major challenges involve false positives in conditions of inflammation and nonpancreatic cancers and false negatives in Lewis-negative Individuals. Lewis antigen status should be determined when using CA19-9 as a biomarker. CA19-9 has screening potential when combined with symptoms and/or risk factors. As a predictor, CA19-9 could be used to assess stage, prognosis, resectability, recurrence, and therapeutic efficacy. Normal baseline levels of CA19-9 are associated with long-term survival. As a promoter, CA19-9 could be used to evaluate the biology of pancreatic cancer. CA19-9 can accelerate pancreatic cancer progression by glycosylating proteins, binding to E-selectin, strengthening angiogenesis, and mediating the immunological response. CA19-9 is an attractive therapeutic target for cancer, and strategies include therapeutic antibodies and vaccines, CA19-9-guided nanoparticles, and inhibition of CA19-9 biosynthesis.

Disrupted Glycocalyx as a Source of Ocular Surface Biomarkers

The glycocalyx is a dense and diverse coat of glycans and glycoconjugates responsible for maintaining cell surface integrity and regulating the interaction of cells with the external environment. Transmembrane mucins such as MUC1 and MUC16 comprise a major component of the epithelial glycocalyx and are currently used to monitor disease progression in cancer. At the ocular surface, multiple lines of evidence indicate that abnormal expression of the enzymes responsible for glycan biosynthesis during pathological conditions impairs the glycosylation of transmembrane mucins. It is now becoming clear that these changes contribute to modify the interaction of mucins with galectin-3, a multimeric lectin crucial for preserving the ocular surface epithelial barrier. This review highlights the potential of using the epithelial glycocalyx as a reliable source for the generation of biomarkers to diagnose and monitor ocular surface disease.

Biomarkers and Strategy to Detect Preinvasive and Early Pancreatic Cancer: State of the Field and the Impact of the EDRN

Patients afflicted with pancreatic ductal adenocarcinoma (PDAC) face a dismal prognosis, but headway could be made if physicians could identify the disease earlier. A compelling strategy to broaden the use of surveillance for PDAC is to incorporate molecular biomarkers in combination with clinical analysis and imaging tools. This article summarizes the components involved in accomplishing biomarker validation and an analysis of the requirements of molecular biomarkers for disease surveillance. We highlight the significance of consortia for this research and highlight resources and infrastructure of the Early Detection Research Network (EDRN). The EDRN brings together the multifaceted expertise and resources needed for biomarker validation, such as study design, clinical care, biospecimen collection and handling, molecular technologies, and biostatistical analysis, and studies coming out of the EDRN have yielded biomarkers that are moving forward in validation. We close the article with an overview of the current investigational biomarkers, an analysis of their performance relative to the established benchmarks, and an outlook on the current needs in the field. The outlook for improving the early detection of PDAC looks promising, and the pace of further research should be quickened through the resources and expertise of the EDRN and other consortia.See all articles in this CEBP Focus section, "NCI Early Detection Research Network: Making Cancer Detection Possible."

Monoclonal Antibody Targeting Sialyl-di-Lewisa-Containing Internalizing and Noninternalizing Glycoproteins with Cancer Immunotherapy Development Potential

Tumor glycans constitute attractive targets for therapeutic antibodies. The sialylated glycocalyx plays a prominent role in cancer progression and immune evasion. Here, we describe the characterization of the mAb, FG129, which targets tumor-associated sialylated glycan, and demonstrate its potential for multimodal cancer therapy. FG129, obtained through BALB/c mouse immunizations with liposomes containing membrane glycan extracts from the colorectal cancer cell line LS180, is an mIgG1κ that targets sialyl-di-Lewis^a-containing glycoproteins. FG129, as well as its chimeric human IgG1 variant, CH129, binds with nanomolar functional affinity to a range of colorectal, pancreatic, and gastric cancer cell lines. FG129 targets 74% (135/182) of pancreatic, 50% (46/92) of gastric, 36% (100/281) of colorectal, 27% (89/327) of ovarian, and 21% (42/201) of non-small cell lung cancers, by IHC. In our pancreatic cancer cohort, high FG129 glyco-epitope expression was significantly associated with poor prognosis (P = 0.004). Crucially, the glyco-epitope displays limited normal tissue distribution, with FG129 binding weakly to a small percentage of cells within gallbladder, ileum, liver, esophagus, pancreas, and thyroid tissues. Owing to glyco-epitope internalization, we validated payload delivery by CH129 through monomethyl auristatin E (MMAE) or maytansinoid (DM1 and DM4) conjugation. All three CH129 drug conjugates killed high-binding colorectal and pancreatic cancer cell lines with (sub)nanomolar potency, coinciding with significant in vivo xenograft tumor control by CH129-vcMMAE. CH129, with its restricted normal tissue distribution, avid tumor binding, and efficient payload delivery, is a promising candidate for the treatment of sialyl-di-Lewis^a-expressing solid tumors, as an antibody-drug conjugate or as an alternative cancer immunotherapy modality.

Single molecule characterization of individual extracellular vesicles from pancreatic cancer

Biofluid-accessible extracellular vesicles (EVs) may represent a new means to improve the sensitivity and specificity of detecting disease. However, current methods to isolate EVs encounter challenges when they are used to select specific populations. Moreover, it has been difficult to comprehensively characterize heterogeneous EV populations at the single vesicle level. Here, we robustly assessed heterogeneous EV populations from cultured cell lines via nanoparticle tracking analysis, proteomics, transcriptomics, transmission electron microscopy, and quantitative single molecule localization microscopy (qSMLM). Using qSMLM, we quantified the size and biomarker content of individual EVs. We applied qSMLM to patient plasma samples and identified a pancreatic cancer-enriched EV population. Our goal is to advance single molecule characterization of EVs for early disease detection.

Abbreviations: EV: Extracellular Vesicle; qSMLM: quantitative Single Molecule Localization Microscopy; PDAC: Pancreatic Ductal Adenocarcinoma; EGFR: epidermal growth factor receptor 1; CA19-9: carbohydrate antigen 19-9; SEC: size exclusion chromatography; WGA: wheat germ agglutinin; AF647: Alexa Fluor 647; Ab: antibody; HPDEC: Healthy Pancreatic Ductal Epithelial Cell; TEM: Transmission Electron Microscopy.

The glycosylation landscape of pancreatic cancer

Pancreatic adenocarcinoma is a lethal disease with a 5-year survival rate of <5%, the lowest of all types of cancer. The diagnosis of pancreatic cancer relies on imaging and tissue biopsy, and the only curative therapy is complete surgical resection. Pancreatic cancer has the propensity to metastasise at an early stage and the majority of patients are diagnosed when surgery is no longer an option. Hence, there is an urgent need to identify biomarkers to enable early diagnosis, and to develop new therapeutic strategies. One approach for this involves targeting cancer-associated glycans. The most widely used serological marker in pancreatic cancer is the carbohydrate antigen CA 19-9 which contains a glycan known as sialyl Lewis A (sLeA). The CA 19-9 assay is used routinely to monitor response to treatment, but concerns have been raised about its sensitivity and specificity as a diagnostic biomarker. In addition to sLeA, a wide range of alterations to other important glycans have been observed in pancreatic cancer. These include increases in the sialyl Lewis X antigen (sLex), an increase in truncated O-glycans (Tn and sTn), increased branched and fucosylated N-glycans, upregulation of specific proteoglycans and galectins, and increased O-GlcNAcylation. Growing evidence supports crucial roles for glycans in all stages of cancer progression, and it is well established that glycans regulate tumour proliferation, invasion and metastasis. The present review describes the biological significance of glycans in pancreatic cancer, and discusses the clinical value of exploiting aberrant glycosylation to improve the diagnosis and treatment of this deadly disease.

Antibodies to a CA 19-9 Related Antigen Complex Identify SOX9 Expressing Progenitor Cells In Human Foetal Pancreas and Pancreatic Adenocarcinoma

The Sialyl Lewis A antigen, or CA 19-9, is the prototype serum biomarker for adenocarcinoma of the pancreas. Despite extensive clinical study of CA 19-9 in gastrointestinal malignancies, surprisingly little is known concerning the specific cell types that express this marker during development, tissue regeneration and neoplasia. SOX9 is a transcription factor that plays a key role in these processes in foregut tissues. We report the biochemistry and tissue expression of the GCTM-5 antigen, a pancreatic cancer marker related to, but distinct from, CA19-9. This antigen, defined by two monoclonal antibodies recognising separate epitopes on a large glycoconjugate protein complex, is co-expressed with SOX9 by foregut ductal progenitors in the developing human liver and pancreas, and in pancreatic adenocarcinoma. These progenitors are distinct from cell populations identified by DCLK1, LGR5, or canonical markers of liver and pancreatic progenitor cells. Co-expression of this antigen complex and SOX9 also characterises the ductal metaplasia of submucosal glands that occurs during the development of Barrett’s oesophagus. The GCTM-5 antigen complex can be detected in the sera of patients with pancreatic adenocarcinoma. The GCTM-5 epitope shows a much more restricted pattern of expression in the normal adult pancreas relative to CA19-9. Our findings will aid in the identification, characterisation, and monitoring of ductal progenitor cells during development and progression of pancreatic adenocarcinoma in man.

The sTRA Plasma Biomarker: Blinded Validation of Improved Accuracy Over CA19-9 in Pancreatic Cancer Diagnosis

PURPOSE

The CA19-9 biomarker is elevated in a substantial group of patients with pancreatic ductal adenocarcinoma (PDAC), but not enough to be reliable for the detection or diagnosis of the disease. We hypothesized that a glycan called sTRA (sialylated tumor-related antigen) is a biomarker for PDAC that improves upon CA19-9.

EXPERIMENTAL DESIGN

We examined sTRA and CA19-9 expression and secretion in panels of cell lines, patient-derived xenografts, and primary tumors. We developed candidate biomarkers from sTRA and CA19-9 in a training set of 147 plasma samples and used the panels to make case-control calls, based on predetermined thresholds, in a 50-sample validation set and a blinded, 147-sample test set.

RESULTS

The sTRA glycan was produced and secreted by pancreatic tumors and models that did not produce and secrete CA19-9. Two biomarker panels improved upon CA19-9 in the training set, one optimized for specificity, which included CA19-9 and 2 versions of the sTRA assay, and another optimized for sensitivity, which included 2 sTRA assays. Both panels achieved statistical improvement (P < 0.001) over CA19-9 in the validation set, and the specificity-optimized panel achieved statistical improvement (P < 0.001) in the blinded set: 95% specificity and 54% sensitivity (75% accuracy), compared with 97%/30% (65% accuracy). Unblinding produced further improvements and revealed independent, complementary contributions from each marker.

CONCLUSIONS

sTRA is a validated serological biomarker of PDAC that yields improved performance over CA19-9. The new panels may enable surveillance for PDAC among people with elevated risk, or improved differential diagnosis among patients with suspected pancreatic cancer.

Human Organoids Share Structural and Genetic Features with Primary Pancreatic Adenocarcinoma Tumors

Patient-derived pancreatic ductal adenocarcinoma (PDAC) organoid systems show great promise for understanding the biological underpinnings of disease and advancing therapeutic precision medicine. Despite the increased use of organoids, the fidelity of molecular features, genetic heterogeneity, and drug response to the tumor of origin remain important unanswered questions limiting their utility. To address this gap in knowledge, primary tumor- and patient-derived xenograft (PDX)-derived organoids, and 2D cultures for in-depth genomic and histopathologic comparisons with the primary tumor were created. Histopathologic features and PDAC representative protein markers (e.g., claudin 4 and CA19-9) showed strong concordance. DNA- and RNA-sequencing (RNAseq) of single organoids revealed patient-specific genomic and transcriptomic consistency. Single-cell RNAseq demonstrated that organoids are primarily a clonal population. In drug response assays, organoids displayed patient-specific sensitivities. In addition, the in vivo PDX response to FOLFIRINOX and gemcitabine/abraxane treatments were examined, which was recapitulated in vitro with organoids. This study has demonstrated that organoids are potentially invaluable for precision medicine as well as preclinical drug treatment studies because they maintain distinct patient phenotypes and respond differently to drug combinations and dosage. IMPLICATIONS: The patient-specific molecular and histopathologic fidelity of organoids indicate that they can be used to understand the etiology of the patient's tumor and the differential response to therapies and suggests utility for predicting drug responses.

A systematic review on metabolomics-based diagnostic biomarker discovery and validation in pancreatic cancer

INTRODUCTION

Metabolomics is an emerging approach for early detection of cancer. Along with the development of metabolomics, high-throughput technologies and statistical learning, the integration of multiple biomarkers has significantly improved clinical diagnosis and management for patients.

OBJECTIVES

In this study, we conducted a systematic review to examine recent advancements in the oncometabolomics-based diagnostic biomarker discovery and validation in pancreatic cancer.

METHODS

PubMed, Scopus, and Web of Science were searched for relevant studies published before September 2017. We examined the study designs, the metabolomics approaches, and the reporting methodological quality following PRISMA statement. RESULTS AND CONCLUSION: The included 25 studies primarily focused on the identification rather than the validation of predictive capacity of potential biomarkers. The sample size ranged from 10 to 8760. External validation of the biomarker panels was observed in nine studies. The diagnostic area under the curve ranged from 0.68 to 1.00 (sensitivity: 0.43-1.00, specificity: 0.73-1.00). The effects of patients' bio-parameters on metabolome alterations in a context-dependent manner have not been thoroughly elucidated. The most reported candidates were glutamic acid and histidine in seven studies, and glutamine and isoleucine in five studies, leading to the predominant enrichment of amino acid-related pathways. Notably, 46 metabolites were estimated in at least two studies. Specific challenges and potential pitfalls to provide better insights into future research directions were thoroughly discussed. Our investigation suggests that metabolomics is a robust approach that will improve the diagnostic assessment of pancreatic cancer. Further studies are warranted to validate their validity in multi-clinical settings.

Circulating biomarkers for early diagnosis of pancreatic cancer: facts and hopes

Pancreatic cancer (PC) is characterized by extremely high mortality and poor prognosis, which are largely ascribed to difficulties in early diagnosis and limited therapeutics. Although there is a sufficient window for intervention before preneoplastic lesions progress to invasive disease, effective early detection of PC remains difficult using current biomarkers and imaging techniques. Biomarkers with satisfactory diagnostic efficacy and convenient analysis methods are urgently required. In this review, we summarized recent advances in the identification of biomarkers in circulation for early detection of PC. A number of novel circulating biomarkers, such as metabolites, cell-free DNA (cfDNA), noncoding RNA, and exosomes, that show promising diagnostic value have been discovered using advances in sequencing techniques and "omics" analyses. Panels comprising several biomarkers may also exhibit better diagnostic performance. In the future, we need more efficient circulating biomarkers for the identification of noninvasive precursor lesions and early disease. Collaborative large-scale studies are also required to show the clinical validity and applicability of potential biomarkers.

Genetic correction improves prediction efficiency of serum tumor biomarkers on digestive cancer risk in the elderly Chinese cohort study

Although serum tumor biomarkers alpha-fetoprotein (AFP), carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA) have been used in digestive cancer risk prediction, the prediction efficiency remains unsatisfactory. The aim of this study was to evaluate whether genetic correction could improve the efficiency of these biomarkers for prediction of digestive cancer risk. We conducted a prospective analysis in 9,808 healthy individuals based on a cohort study in the elderly Chinese population. The genotypes of reported single nucleotide polymorphisms (SNPs) associated with serum AFP, CA19-9 and CEA were used to estimate the genetic corrected levels of these markers. Unconditional logistic regression analysis was performed to evaluate the risk of digestive cancer. The Harrell's C-statistic was used to evaluate the discriminative ability of the raw levels and genetic corrected levels of biomarkers on digestive cancer risk. Up to October 2013, a total of 172 individuals were newly diagnosed with digestive cancer. With the genetic correction, higher odds ratios (ORs) for digestive cancer risk were found for the genetic corrected levels of tumor biomarkers compared with their raw serum levels (1.57 vs. 1.65 for AFP; 1.19 vs. 1.21 for CA19-9; 1.09 vs. 1.10 for CEA, respectively). The same results were observed in the Harrell's C-statistic analyses. Genetic correction improved the prediction efficiency of tumor biomarkers on the digestive cancer risk in an elderly Chinese population. Our findings provide evidence for further studies of genetic effects on tumor biomarker to improve the predictive efficiency on cancer risk.

Endoscopic Evaluation in the Workup of Pancreatic Cancer

Early diagnosis and accurate staging of pancreatic cancer is very important to plan optimal management strategy. Endoscopy plays an important role in the diagnosis and management of pancreatic cancer. Endoscopic ultrasound imaging (EUS) is the most sensitive modality for diagnosis, especially for small pancreatic tumors; it also allows tissue acquisition for histological diagnosis. Computed tomography scanning and EUS play complementary roles in staging and are comparable in determining resectability. Endoscopic retrograde cholangiopancreatography allows tissue sampling but is limited to palliative biliary drainage in most cases. In this article, we review the role of endoscopy in the diagnosis and management of pancreatic adenocarcinoma, with special emphasis on the use of endoscopic ultrasound and endoscopic retrograde cholangiopancreatography (ERCP).

Gemcitabine-Based Regional Intra-Arterial Infusion Chemotherapy in Patients With Advanced Pancreatic Adenocarcinoma

The present study was carried out to investigate the prognostic factors in patients who received intra-arterial infusion for advanced pancreatic cancer. In addition, the detailed procedure of intra-arterial infusion chemotherapy was described. A total of 354 patients with advanced unresectable pancreatic adenocarcinoma were recruited from January 2012, to April 2015, at Zhongshan Hospital Fudan University, Shanghai, China. Demographic and clinic characteristics of the patients were extracted from electronic medical records. Restricted cubic spline was used to assess the nonliner regression between baseline CA19-9 value and overall survival. Kaplan-Meier analysis and Cox proportional hazard models were used to estimate the association between overall survival and clinical characteristics. Of all 354 included patients, 230 (65%) were male (male/female ratio = 1.8), and 72 (20%) patients were diagnosed with detectable distant metastases. Pretreatment CA19-9 value of patients with metastases was significantly higher as compared to those with locally advanced cancer (median: 922.30 vs 357.00 U/mL, P = 0.0090). Totally 274 patients completed 1 cycle of intra-arterial infusion, whereas 80 patients received 2 or more cycles of the chemotherapy. For all the 354 patients, median OS was 7.0 months (95% CI: 6.0, 8.0 months) with a 6-, 12-, and 18-month survival rate of 0.48, 0.28, and 0.18, respectively. The median OS of patients, who received 1 cycle of intra-arterial infusion therapy, was 6.0 months (95% CI: 5.0, 8.0 months), which was similar to 7.0 months (95% CI: 6.0, 9.0 months) in patients who received 2 or more cycles. Restricted cubic spline revealed the nonline association between baseline CA19-9 and prognosis. The Cox proportional hazard model showed that age, CA19-9 baseline, CA19-9 value, and tumor location were significantly associated with the OS. In conclusion, the gemcitabine-based RIAC presented a potential treatment method for advanced pancreatic adenocarcinoma. Young age, pretreatment CA19-9 value <1000 U/mL, and tumor located at the head of pancreas indicated better response to the regional intra-arterial chemotherapy and better overall survival.

A Synthetic Glycopeptide Vaccine for the Induction of a Monoclonal Antibody that Differentiates between Normal and Tumor Mammary Cells and Enables the Diagnosis of Human Pancreatic Cancer

In studies within the realm of cancer immunotherapy, the synthesis of exactly specified tumor-associated glycopeptide antigens is shown to be a key strategy for obtaining a highly selective biological reagent, that is, a monoclonal antibody that completely differentiates between tumor and normal epithelial cells and specifically marks the tumor cells in pancreas tumors. Mucin MUC1, which is overexpressed in many prevalent cancers, was identified as a promising target for this strategy. Tumor-associated MUC1 differs significantly from that expressed by normal cells, in particular by altered glycosylation. Structurally defined tumor-associated MUC1 cannot be isolated from tumor cells. We synthesized MUC1-glycopeptide vaccines and analyzed their structure-activity relationships in immunizations; a monoclonal antibody that specifically distinguishes between human normal and tumor epithelial cells was thus generated.

Glycans related to the CA19-9 antigen are elevated in distinct subsets of pancreatic cancers and improve diagnostic accuracy over CA19-9

BACKGROUND AND AIMS

The CA19-9 antigen is the current best biomarker for pancreatic cancer, but it is not elevated in about 25% of pancreatic cancer patients at a cutoff that gives a 25% false-positive rate. We hypothesized that antigens related to the CA19-9 antigen, which is a glycan called sialyl-Lewis A (sLeA), are elevated in distinct subsets of pancreatic cancers.

METHODS

We profiled the levels of multiple glycans and mucin glycoforms in plasma from 200 subjects with either pancreatic cancer or benign pancreatic disease, and we validated selected findings in additional cohorts of 116 and 100 subjects, the latter run blinded and including cancers that exclusively were early-stage.

RESULTS

We found significant elevations in two glycans: an isomer of sLeA called sialyl-Lewis X, present both in sulfated and non-sulfated forms; and the sialylated form of a marker for pluripotent stem cells, type 1 N-acetyl-lactosamine. The glycans performed as well as sLeA as individual markers and were elevated in distinct groups of patients, resulting in a 3-marker panel that significantly improved upon any individual biomarker. The panel gave 85% sensitivity and 90% specificity in the combined discovery and validation cohorts, relative to 54% sensitivity and 86% specificity for sLeA; and it gave 80% sensitivity and 84% specificity in the independent test cohort, as opposed to 66% sensitivity and 72% specificity for sLeA.

CONCLUSIONS

Glycans related to sLeA are elevated in distinct subsets of pancreatic cancers and yield improved diagnostic accuracy over CA19-9.

Controlled Film Architectures to Detect a Biomarker for Pancreatic Cancer Using Impedance Spectroscopy

The need for analytical devices for detecting cancer at early stages has motivated research into nanomaterials where synergy is sought to achieve high sensitivity and selectivity in low-cost biosensors. In this study, we developed a film architecture combining self-assembled monolayer (SAM) and layer-by-layer (LbL) films of polysaccharide chitosan and the protein concanavalin A, on which a layer of anti-CA19-9 antibody was adsorbed. Using impedance spectroscopy with this biosensor, we were capable of detecting low concentrations of the antigen CA19-9, an important biomarker for pancreatic cancer. The limit of detection of 0.69U/mL reached is sufficient for detecting pancreatic cancer at very early stages. The selectivity of the biosensor was inferred from a series of control experiments with samples of cell lines that were tested positive (HT29) and negative (SW620) for the biomarker CA19-9, in addition to the lack of changes in the capacitance value for other analytes and antigen that are not related to this type of cancer. The high sensitivity and selectivity are ascribed to the very specific antigen-antibody interaction, which was confirmed with PM-IRRAS and atomic force microscopy. Also significant is that used information visualization methods to show that different cell lines and commercial samples containing distinct concentrations of CA19-9 and other analytes can be easily distinguished from each other. These computational methods are generic and may be used in optimization procedures to tailor biosensors for specific purposes, as we demonstrated here by comparing the performance of two film architectures in which the concentration of chitosan was varied.

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.

Definitive Characterization of CA 19-9 in Resectable Pancreatic Cancer Using a Reference Set of Serum and Plasma Specimens

The validation of candidate biomarkers often is hampered by the lack of a reliable means of assessing and comparing performance. We present here a reference set of serum and plasma samples to facilitate the validation of biomarkers for resectable pancreatic cancer. The reference set includes a large cohort of stage I-II pancreatic cancer patients, recruited from 5 different institutions, and relevant control groups. We characterized the performance of the current best serological biomarker for pancreatic cancer, CA 19–9, using plasma samples from the reference set to provide a benchmark for future biomarker studies and to further our knowledge of CA 19–9 in early-stage pancreatic cancer and the control groups. CA 19–9 distinguished pancreatic cancers from the healthy and chronic pancreatitis groups with an average sensitivity and specificity of 70–74%, similar to previous studies using all stages of pancreatic cancer. Chronic pancreatitis patients did not show CA 19–9 elevations, but patients with benign biliary obstruction had elevations nearly as high as the cancer patients. We gained additional information about the biomarker by comparing two distinct assays. The two CA 9–9 assays agreed well in overall performance but diverged in measurements of individual samples, potentially due to subtle differences in antibody specificity as revealed by glycan array analysis. Thus, the reference set promises be a valuable resource for biomarker validation and comparison, and the CA 19–9 data presented here will be useful for benchmarking and for exploring relationships to CA 19–9.

Lectin Microarray-Based Sero-Biomarker Verification Targeting Aberrant O-Linked Glycosylation on Mucin 1

Glycoform of mucin 1 (MUC1) in cancerous cells changes markedly with cell differentiation, and thus, qualitative detection and verification of the MUC1 glycosylation changes have potential diagnostic value. We have developed an ultrasensitive method to detect the changes in cholangiocarcinoma (CC), which produces MUC1, and applied it in the diagnostics development. The focused glycan analysis using 43-lectin-immobilized microarray could obtain the glycan profiles of sialylated MUC1 in 5 μL of sera. The high-throughput analysis detected disease-specific alterations of glycosylation, and the statistical analysis confirmed that use of Wisteria floribunda agglutinin (WFA) alone produced a diagnostic score sufficient for discriminating 33 CC cases from 40 hepatolithiasis patients and 48 normal controls (p < 0.0001). The CC-related glycosylation change was verified by the lectin-antibody sandwich ELISA with WFA in two cohorts: (1) 78 Opisthorchis viverrini infected patients without CC and 78 with CC, (2) 33 CC patients and 40 hepatolithiasis patients (the same cohort used for the above lectin microarray). The WFA positivity distinguished patients with CC (opisthorchiasis: p < 0.0001, odds ratio = 1.047; hepatolithiasis: p = 0.0002, odds ratio = 1.018). Sensitive detection of qualitative alterations of sialylated MUC1 glycosylation is indispensable for the development of our glycodiagnostic test for CC.

Upregulation of glycans containing 3' fucose in a subset of pancreatic cancers uncovered using fusion-tagged lectins

The fucose post-translational modification is frequently increased in pancreatic cancer, thus forming the basis for promising biomarkers, but a subset of pancreatic cancer patients does not elevate the known fucose-containing biomarkers. We hypothesized that such patients elevate glycan motifs with fucose in linkages and contexts different from the known fucose-containing biomarkers. We used a database of glycan array data to identify the lectins CCL2 to detect glycan motifs with fucose in a 3' linkage; CGL2 for motifs with fucose in a 2' linkage; and RSL for fucose in all linkages. We used several practical methods to test the lectins and determine the optimal mode of detection, and we then tested whether the lectins detected glycans in pancreatic cancer patients who did not elevate the sialyl-Lewis A glycan, which is upregulated in ∼75% of pancreatic adenocarcinomas. Patients who did not upregulate sialyl-Lewis A, which contains fucose in a 4' linkage, tended to upregulate fucose in a 3' linkage, as detected by CCL2, but they did not upregulate total fucose or fucose in a 2' linkage. CCL2 binding was high in cancerous epithelia from pancreatic tumors, including areas negative for sialyl-Lewis A and a related motif containing 3' fucose, sialyl-Lewis X. Thus, glycans containing 3' fucose may complement sialyl-Lewis A to contribute to improved detection of pancreatic cancer. Furthermore, the use of panels of recombinant lectins may uncover details about glycosylation that could be important for characterizing and detecting cancer.

Glycan motif profiling reveals plasma sialyl-lewis x elevations in pancreatic cancers that are negative for sialyl-lewis A

The sialyl-Lewis A (sLeA) glycan forms the basis of the CA19-9 assay and is the current best biomarker for pancreatic cancer, but because it is not elevated in ∼25% of pancreatic cancers, it is not useful for early diagnosis. We hypothesized that sLeA-low tumors secrete glycans that are related to sLeA but not detectable by CA19-9 antibodies. We used a method called motif profiling to predict that a structural isomer of sLeA called sialyl-Lewis X (sLeX) is elevated in the plasma of some sLeA-low cancers. We corroborated this prediction in a set of 48 plasma samples and in a blinded set of 200 samples. An antibody sandwich assay formed by the capture and detection of sLeX was elevated in 13 of 69 cancers that were not elevated in sLeA, and a novel hybrid assay of sLeA capture and sLeX detected 24 of 69 sLeA-low cancers. A two-marker panel based on combined sLeA and sLeX detection differentiated 109 pancreatic cancers from 91 benign pancreatic diseases with 79% accuracy (74% sensitivity and 78% specificity), significantly better than sLeA alone, which yielded 68% accuracy (65% sensitivity and 71% specificity). Furthermore, sLeX staining was evident in tumors that do not elevate plasma sLeA, including those with poorly differentiated ductal adenocarcinoma. Thus, glycan-based biomarkers could characterize distinct subgroups of patients. In addition, the combined use of sLeA and sLeX, or related glycans, could lead to a biomarker panel that is useful in the clinical diagnosis of pancreatic cancer. Précis: This paper shows that a structural isomer of the current best biomarker for pancreatic cancer, CA19-9, is elevated in the plasma of patients who are low in CA19-9, potentially enabling more comprehensive detection and classification of pancreatic cancers.

The detection and discovery of glycan motifs in biological samples using lectins and antibodies: new methods and opportunities

Recent research has uncovered unexpected ways that glycans contribute to biology, as well as new strategies for combatting disease using approaches involving glycans. To make full use of glycans for clinical applications, we need more detailed information on the location, nature, and dynamics of glycan expression in vivo. Such studies require the use of specimens acquired directly from patients. Effective studies of clinical specimens require low-volume assays, high precision measurements, and the ability to process many samples. Assays using affinity reagents-lectins and glycan-binding antibodies-can meet these requirements, but further developments are needed to make the methods routine and effective. Recent advances in the use of glycan-binding proteins involve improved determination of specificity using glycan arrays; the availability of databases for mining and analyzing glycan array data; lectin engineering methods; and the ability to quantitatively interpret lectin measurements. Here, we describe many of the challenges and opportunities involved in the application of these new approaches to the study of biological samples. The new tools hold promise for developing methods to improve the outcomes of patients afflicted with diseases characterized by aberrant glycan expression.

Glycoprotein biomarker panel for pancreatic cancer discovered by quantitative proteomics analysis

Pancreatic cancer is a lethal disease where specific early detection biomarkers would be very valuable to improve outcomes in patients. Many previous studies have compared biosamples from pancreatic cancer patients with healthy controls to find potential biomarkers. However, a range of related disease conditions can influence the performance of these putative biomarkers, including pancreatitis and diabetes. In this study, quantitative proteomics methods were applied to discover potential serum glycoprotein biomarkers that distinguish pancreatic cancer from other pancreas related conditions (diabetes, cyst, chronic pancreatitis, obstructive jaundice) and healthy controls. Aleuria aurantia lectin (AAL) was used to extract fucosylated glycoproteins and then both TMT protein-level labeling and label-free quantitative analysis were performed to analyze glycoprotein differences from 179 serum samples across the six different conditions. A total of 243 and 354 serum proteins were identified and quantified by label-free and TMT protein-level quantitative strategies, respectively. Nineteen and 25 proteins were found to show significant differences in samples between the pancreatic cancer and other conditions using the label-free and TMT strategies, respectively, with 7 proteins considered significant in both methods. Significantly different glycoproteins were further validated by lectin-ELISA and ELISA assays. Four candidates were identified as potential markers with profiles found to be highly complementary with CA 19–9 (p < 0.001). Obstructive jaundice (OJ) was found to have a significant impact on the performance of every marker protein, including CA 19–9. The combination of α-1-antichymotrypsin (AACT), thrombospondin-1 (THBS1), and haptoglobin (HPT) outperformed CA 19–9 in distinguishing pancreatic cancer from normal controls (AUC = 0.95), diabetes (AUC = 0.89), cyst (AUC = 0.82), and chronic pancreatitis (AUC = 0.90). A marker panel of AACT, THBS1, HPT, and CA 19–9 showed a high diagnostic potential in distinguishing pancreatic cancer from other conditions with OJ (AUC = 0.92) or without OJ (AUC = 0.95).

CA 19-9: handle with care

Since its inception in the mid-1980s of the 20th century testing for carbohydrate antigen 19-9 (CA 19-9) has raised expectation for an earlier diagnosis and accurate monitoring of several malignant diseases. After almost 30 years, the available evidences have confirmed the appropriateness and usefulness of determining CA 19-9 levels as a prognostic indicator and as a reliable tool for monitoring pancreatic and gastrointestinal cancer, but concerns have been raised about its applications in screening, which is actually not recommended, and in the diagnosis of malignancies, due to several interferences that limit the specificity and to the insufficient sensitivity of this marker. In this paper we aimed to review the basic concepts of CA 19-9 testing and its current applications, with a major focus on the most recent evidences dealing with assay interference, methods comparison and monitoring of malignant diseases. The prognostic value and monitoring recommendations for pancreatic, gastric and colorectal cancers are described in depth.

Modulation of glycan recognition by clustered saccharide patches

All cells in nature are covered with a dense and complex array of glycan chains. Specific recognition and binding of glycans is a critical aspect of cellular interactions, both within and between species. Glycan-protein interactions tend to be of low affinity but high specificity, typically utilizing multivalency to generate the affinity required for biologically relevant binding. This review focuses on a higher level of glycan organization, the formation of clustered saccharide patches (CSPs), which can constitute unique ligands for highly specific interactions. Due to technical challenges, this aspect of glycan recognition remains poorly understood. We present a wealth of evidence for CSPs-mediated interactions, and discuss recent advances in experimental tools that are beginning to provide new insights into the composition and organization of CSPs. The examples presented here are likely the tip of the iceberg, and much further work is needed to elucidate fully this higher level of glycan organization.

Production of a recombinant antibody specific for i blood group antigen, a mesenchymal stem cell marker

Multipotent mesenchymal stem/stromal cells (MSCs) offer great promise for future regenerative and anti-inflammatory therapies. Panels of functional and phenotypical markers are currently used in characterization of different therapeutic stem cell populations from various sources. The i antigen (linear poly-N-acetyllactosamine) from the Ii blood group system has been suggested as a marker for MSCs derived from umbilical cord blood (UCB). However, there are currently no commercially available antibodies recognizing the i antigen. In the present study, we describe the use of antibody phage display technology to produce recombinant antibodies recognizing a structure from the surface of mesenchymal stem cells. We constructed IgM phage display libraries from the lymphocytes of a donor with an elevated serum anti-i titer. Antibody phage display technology is not dependent on immunization and thus allows the generation of antibodies against poorly immunogenic molecules, such as carbohydrates. Agglutination assays utilizing i antigen–positive red blood cells (RBCs) from UCB revealed six promising single-chain variable fragment (scFv) antibodies, three of which recognized epitopes from the surface of UCB-MSCs in flow cytometric assays. The amino acid sequence of the V_H gene segment of B12.2 scFv was highly similar to the V_H4.21 gene segment required to encode anti-i specificities. Further characterization of binding properties revealed that the binding of B12.2 hyperphage was inhibited by soluble linear lactosamine oligosaccharide. Based on these findings, we suggest that the B12.2 scFv we have generated is a prominent anti-i antibody that recognizes i antigen on the surface of both UCB-MSCs and RBCs. This binder can thus be utilized in UCB-MSC detection and isolation as well as in blood group serology.

The Marker State Space (MSS) method for classifying clinical samples

The development of accurate clinical biomarkers has been challenging in part due to the diversity between patients and diseases. One approach to account for the diversity is to use multiple markers to classify patients, based on the concept that each individual marker contributes information from its respective subclass of patients. Here we present a new strategy for developing biomarker panels that accounts for completely distinct patient subclasses. Marker State Space (MSS) defines “marker states” based on all possible patterns of high and low values among a panel of markers. Each marker state is defined as either a case state or a control state, and a sample is classified as case or control based on the state it occupies. MSS was used to define multi-marker panels that were robust in cross validation and training-set/test-set analyses and that yielded similar classification accuracy to several other classification algorithms. A three-marker panel for discriminating pancreatic cancer patients from control subjects revealed subclasses of patients based on distinct marker states. MSS provides a straightforward approach for modeling highly divergent subclasses of patients, which may be adaptable for diverse applications.

Glycoprotein disease markers and single protein-omics

Glycoproteins are well represented among biomarkers for inflammatory and cancer diseases. Secreted and membrane-associated glycoproteins make excellent targets for noninvasive detection. In this review, we discuss clinically applicable markers of cancer diseases and methods for their analysis. High throughput discovery continues to supply marker candidates with unusual glycan structures, altered glycoprotein abundance, or distribution of site-specific glycoforms. Improved analytical methods are needed to unlock the potential of these discoveries in validated clinical assays. A new generation of targeted quantitative assays is expected to advance the use of glycoproteins in early detection of diseases, molecular disease classification, and monitoring of therapeutic interventions.

Therapeutic targeting of Lewis(y) and Lewis(b) with a novel monoclonal antibody 692/29

Background

Several monoclonal antibodies (mAbs) recognising Lewis^y, such as BR96, have reached the clinic but have failed to show good anti-tumour responses with an acceptable level of toxicity. No Lewis^b mAbs have been trialled in patients. In this study we compare the specificity of three mAbs; BR96 (Lewis^y), 2-25 LE (Lewis^b) and 692/29 that recognises a unique facet of both Lewis^y and Lewis^b. We then assessed the in vivo therapeutic effect of 692/29 using xenograft models.

Methodology/Principal Findings

Using a glycan array, each mAb was shown to display a different binding pattern with only 692/29 binding to both Lewis^y and Lewis^b. 692/29 was able to kill tumour cells over-expressing Lewis^y/b directly, as well as by antibody and complement mediated cytotoxicity (ADCC/CDC), but failed to kill cells expressing low levels of these haptens. In contrast, BR96, directly killed cells expressing either high or low levels of Lewis^y perhaps explaining its toxicity in patients. 2-25 LE failed to cause any direct killing but did mediate ADCC/CDC. Both 692/29 and BR96 bound to >80% of a panel of over 400 colorectal tumours whereas 2-25 LE showed lower reactivity (52%). 692/29 demonstrated more restricted normal tissue reactivity than both BR96 and 2-25 LE. 692/29 anti-Lewis^y/b mAb also showed good in vivo killing in xenograft models.

Conclusions/Significance

MAbs targeting both Lewis^y and Lewis^b may have a therapeutic advantage over mAbs targeting just one hapten. 692/29 has a more restricted normal tissue distribution and a higher antigen threshold for killing which should reduce its toxicity compared to a Lewis^y specific mAb. 692/29 has an ability to directly kill tumours whereas the anti-Lewis^b mAb does not. This suggests that Lewis^y but not Lewis^b are functional glycans. 692/29 showed good anti-tumour responses in vivo and is a strong therapeutic candidate.

Early diagnosis of pancreatic cancer: challenges and new developments

Pancreatic cancer is a lethal malignancy with its incidence almost equivalent to mortality. The complex pathophysiology, absence of early diagnostic and prognostic markers and unresponsiveness to radiation and chemotherapies are major barriers against successful therapy. Poor performance of therapeutic agents, even in the initial stage of invasive cases, emphasizes the importance of early detection for improved survival. The present review discusses the challenges and advances in biomarkers including serological signatures, circulating tumor cells, autoantibodies, epigenetic markers and miRNAs that are being explored to detect this cancer at early stages. Considering the long time gap between the development of malignant lesions and full-blown primary and metastatic pancreatic cancer, unique opportunities are being contemplated for the development of potential diagnostic and prognostic markers.