Serum fucosylation changes in oral cancer and oral precancerous conditions: alpha-L-fucosidase as a marker

Identification of stemness-related glycosylation changes in head and neck squamous cell carcinoma

BACKGROUND

Altered glycosylation is a hallmark of cancer associated with therapy resistance and tumor behavior. In this study, we investigated the glycosylation profile of stemness-related proteins OCT4, CIP2A, MET, and LIMA1 in HNSCC tumors.

METHODS

Tumor, adjacent normal tissue, and blood samples of 25 patients were collected together with clinical details. After tissue processing, lectin-based glycovariant screens were performed.

RESULTS

Strong correlation between glycosylation profiles of all four stemness-related proteins was observed in tumor tissue, whereas glycosylation in tumor tissue, adjacent normal tissue, and serum was differential.

CONCLUSIONS

A mannose- and galactose-rich glycosylation niche associated with stemness-related proteins was identified.

Assessment of Serum Fucose Level among Oral Squamous Cell Carcinoma Patients: A Case-Control Study

Background

Serum glycoproteins, which are made up of various monosaccharides, are altered in malignancy, a disorder of cellular conduct. L-fucose, a methyl pentose that serves as the last sugar in the majority of plasma glycoproteins, is one of the monosaccharides. Numerous illness conditions and cancers have been linked to increased levels of protein-bound fucose.

Materials and Methods

In the current study, the serum fucose levels of patients with oral squamous cell carcinoma (OSCC) and healthy individuals were assessed and compared. The present study included a total of 30 OSCC patients and 30 healthy controls. The Winzler method was used to estimate the serum L-fucose levels using a spectrophotometer (Spectronic 20, Thermo Fisher Scientific, USA).

Results

Age and sex had no effect on serum fucose levels. In contrast to healthy individuals, OSCC patients' mean serum fucose levels significantly increased. In conclusion, patients with OSCC can benefit from the use of serum fucose as an investigative biomarker.

Oral Sources of Salivary Metabolites

The oral cavity is very diverse, where saliva plays an important role in maintaining oral health. The metabolism of saliva has been used to investigate oral diseases as well as general diseases, mainly to detect diagnostic biomarkers. There are many sources of salivary metabolites in the mouth. The online English language search and PubMed databases were searched to retrieve relevant studies on oral salivary metabolites. The physiological balance of the mouth is influenced by many factors that are reflected in the salivary metabolite profile. Similarly, the dysbiosis of microbes can alter the salivary metabolite profile, which may express oral inflammation or oral diseases. This narrative review highlights the factors to be considered when examining saliva and its use as a diagnostic biofluid for different diseases. Salivary metabolites, mainly small molecular metabolites may enter the bloodstream and cause illness elsewhere in the body. The importance of salivary metabolites produced in the oral cavity as risk factors for general diseases and their possible relationship to the body’s function are also discussed.

alpha2,3 sialic acid processing enzymes expression in gastric cancer tissues reveals that ST3Gal3 but not Neu3 are associated with Lauren's classification, angiolymphatic invasion and histological grade

Gastric cancer (GC) is one of the leading causes of cancer-related deaths worldwide. Despite progress in the last decades, there are still no reliable biomarkers for the diagnosis of and prognosis for GC. Aberrant sialylation is a widespread critical event in the development of GC. Neuraminidases (Neu) and sialyltransferases (STs) regulate the ablation and addition of sialic acid during glycoconjugates biosynthesis, and they are a considerable source of biomarkers in various cancers. This study retrospectively characterized Neu3 and ST3Gal3 expression by immunohistochemistry in 71 paraffin-embedded GC tissue specimens and analyzed the relationship between their expression and the clinicopathological parameters. Neu3 expression was markedly increased in GC tissues compared with non-tumoral tissues (p<0.0001). Intratumoral ST3Gal3 staining was significantly associated with intestinal subtype (p=0.0042) and was negatively associated with angiolymphatic invasion (p=0.0002) and higher histological grade G3 (p=0.0066). Multivariate analysis revealed that ST3Gal3 positivity is able to predict Lauren's classification. No associations were found between Neu3 staining and clinical parameters. The in silico analysis of mRNA expression in GC validation cohorts corroborates the significant ST3Gal3 association with higher histological grade observed in our study. These findings suggest that ST3Gal3 expression may be an indicator for aggressiveness of primary GC.

Dual role of fucosidase in cancers and its clinical potential

Glycosidases and glycosyltransferases greatly impact malignant phenotype of tumors though genetics and epigenetics mechanisms. As the member of glycoside hydrolase (GH) families 29A, α-L-fucosidases (AFUs) are involved in the hydrolysis of terminal L-fucose residues linked via α-1,2, α-1,3, α-1,4 or α-1,6 to the reducing end of N-acetyl glucosamine (GlcNAc) of oligosaccharide chains. The defucosylation process mediated by AFUs contributes to the development of various diseases, such as chronic inflammatory diseases, immune disorders, and autoimmune diseases by reducing the interaction between fucosylated adhesion molecules supporting leukocyte extravasation. AFUs also impair crucial cell-extracellular matrix (ECM) interactions and presumably subsequent cell signaling pathways, which lead to changes in tumor function and behavior. There are two isoforms of AFUs in human, namely α-L-fucosidase 1 (FUCA1) and α-L-fucosidase 2 (FUCA2), respectively. FUCA1 is a p53 target gene and can hydrolyze different fucosylation sites on epidermal growth factor receptor (EGFR), thereby determining the activation of EGFR. FUCA2 mediates the adhesion between Helicobacter pylori and gastric mucosa and is upregulated in 24 tumor types. Besides, based on the participation of AFU in signaling pathways and tumor progression, we discuss the prospect of AFU as a therapeutic target.

Altered mRNA Expression of Fucosyltransferases and Fucosidase Predicts Prognosis in Human Oral Carcinoma

Aberrant protein glycosylation is known to be associated with the development of various cancers. Although fucosylation is essential for normal biological functions, alterations in fucosylation are strongly implicated in cancer and increasing metastatic potential. Altered fucosyltarnsferases (FUTs) and fucosidases are found to be involved in many types of malignancies. In this study, we examined the mRNA expressions of fucosidase (FUCA1) and FUTs (FUTs (FUT3, FUT4, FUT5, FUT6, FUT8) in human oral cancer tissues. All FUTs and FUCA1 were significantly (P ≤0.05) down-regulated in malignant tissues in comparison with their adjacent normal tissues. The relationship between the clinicopathological parameters and the expression of FUTs and FUCA1 revealed that higher mRNA levels of FUT4, FUT5, and FUT8 and lower levels of FUT3 were associated with progression of disease and lymph node metastasis in oral carcinoma indicating their role in oral cancer progression. Collectively, results suggest that elevated mRNA levels of FUT4, FUT5 and FUT8 may be used as worst prognostic indicators for oral carcinoma.

Differential Glycosylation Levels in Saliva from Patients with Lung or Breast Cancer: A Preliminary Assessment for Early Diagnostic Purposes

Glycans play a fundamental role in several biological processes, such as cell-cell adhesion, signaling, and recognition. Similarly, abnormal glycosylation is involved in many pathological processes, among which include tumor growth and progression. Several highly glycosylated proteins found in blood are currently used in clinical practice as cancer biomarkers (e.g., CA125, PSA, and CA19-9). The development of novel non-invasive diagnostic procedures would greatly simplify the screening and discovery of pathologies at an early stage, thus also allowing for simpler treatment and a higher success rate. In this observational study carried out on 68 subjects diagnosed with either breast or lung cancer and 34 healthy volunteers, we hydrolyzed the glycoproteins in saliva and quantified the obtained free sugars (fucose, mannose, galactose, glucosamine, and galactosamine) by using high-performance anion-exchange chromatography with pulsed-amperometric detection (HPAEC-PAD). The glycosidic profiles were compared by using multivariate statistical analysis, showing differential glycosylation patterns among the three categories. Furthermore, Receiver Operating Characteristics (ROC) analysis allowed obtaining a reliable and minimally invasive protocol able to discriminate between healthy and pathological subjects.

ABO Blood Groups and Its Association with Oral Cancer, Oral Potentially Malignant Disorders and Oral Submucous Fibrosis- A Systematic Review and Meta-Analysis

Objective:

The study aimed to evaluate the association between ABO blood groups and oral cancer, other potentially malignant disorders (OPMD), and oral submucous fibrosis (OSMF).

Materials and methods:

A search was conducted in Medline, Cochrane databases, Google Scholar, Scopus, Web of Science and Directory of Open Access Journals (DOAJ) for studies evaluating ABO blood groups as risk factors for oral cancer and OPMD among cases and controls. The PRISMA guidelines were followed for the meta-analysis. Participants included patients with oral cancer, and OPMD diagnosed using histopathologic investigations. Sub-group analysis was conducted to evaluate the association between blood groups and OSMF. Quality was evaluated using the Risk of Bias Assessment tool. Fixed effects model was used to assess the odds ratio for the association.

Results:

There were 1,352, 414, and 299 cases of oral cancer, OPMD, and OSMF and 11,699, 7,382 and 7,307 controls for analysis respectively. Blood group A was significantly associated with both oral cancer (Odds ratio: 1.27 [95% CI, 1.10, 1.47], P= 0.001) and OPMD (Odds ratio: 1.33 [95% CI, 1.01, 1.47], P= 0.04). No association was noted between blood group B and AB with oral cancer, OPMD, and OSMF. Blood group O was significantly associated with lower chances of oral cancer (Odds ratio: 0.81 [95% CI, 0.71, 0.93], P= 0.002).

Conclusion:

Meta-analysis suggests blood group A has a greater risk for developing oral cancer and OPMD. Blood group O was associated with lower chances of oral cancer. No association was noted between ABO blood group system with OSMF.

The Repertoire of Glycan Alterations and Glycoproteins in Human Cancers

Cancer as the leading cause of death worldwide has many issues that still need to be addressed. Since the alterations on the glycan compositions or/and structures (i.e., glycosylation, sialylation, and fucosylation) are common features of tumorigenesis, glycomics becomes an emerging field examining the structure and function of glycans. In the past, cancer studies heavily relied on genomics and transcriptomics with relatively little exploration of the glycan alterations and glycoprotein biomarkers among individuals and populations. Since glycosylation of proteins increases their structural complexity by several orders of magnitude, glycome studies resulted in highly dynamic biomarkers that can be evaluated for cancer diagnosis, prognosis, and therapy. Glycome not only integrates our genetic background with past and present environmental factors but also offers a promise of more efficient patient stratification compared with genetic variations. Therefore, studying glycans holds great potential for better diagnostic markers as well as developing more efficient treatment strategies in human cancers. While recent developments in glycomics and associated technologies now offer new possibilities to achieve a high-throughput profiling of glycan diversity, we aim to give an overview of the current status of glycan research and the potential applications of the glycans in the scope of the personalized medicine strategies for cancer.

Changes in Protein Glycosylation in Head and Neck Squamous Cell Carcinoma

Glycosylation is an important posttranslational modification of proteins, and it has a profound influence on diverse life processes. An abnormal polysaccharide structure and mutation of the glycosylation pathway are closely correlated with human cancer progression. Glycoproteins such as EGFR, E-cadherin, CD44, PD-1/PD-L1, B7-H3 and Muc1 play important roles in the progression of head and neck squamous cell carcinoma (HNSCC), and their levels of glycosylation and changes in glycosyl structure are closely linked to HNSCC progression and malignant transformation. The regulation of protein glycosylation in HNSCC provides potential strategies to control cancer stem cell (CSC) subgroup expansion, epithelial-mesenchymal transition (EMT), tumor-related immunity escape and autophagy. Glycoproteins with altered glycosylation can be used as biomarkers for the early diagnosis, monitoring and prognostication of HNSCC. However, the glycobiology of cancer is still a new field that needs to be deeply studied, especially in HNSCC.

Salivary Markers in Relation to Oral Squamous Cell Carcinoma in Smokeless Tobacco Users: A Literature Review

Context: Nicotine and carcinogens are present in smokeless tobacco products. Oral, esophageal, and pancreatic cancers have been seen in Smokeless tobacco users. This article aims at reviewing the available literature and summarizing the application of salivary markers in smokeless tobacco users and their association with oral squamous cell carcinoma. Evidence Acquisition: The terms “saliva or salivary”, “markers or biomarkers”, “smokeless tobacco or Chewing tobacco or snuff”, and “oral cancer or oral carcinoma or oral squamous cell carcinoma” were searched in PubMed, MEDLINE, Google Scholar, and Google databases. Original and review English-written articles published over the past 20 years were reviewed, and the appropriate papers were chosen and intently studied. A data form designed by the author was used to write the proper results. Results: Our initial search identified 135 articles, 35 of which met the criteria for entering the final study and were contained for review. In summary, these studies described 20 markers found in the saliva of smokeless tobacco users linked to oral cancer. Conclusions: In this review study, some salivary markers such as cytokines, immunoglobulins, antioxidants, etc. were reviewed. In this review, it was shown that similar changes in these markers occur in patients with cancer and smokeless tobacco users. With the development of these diagnostic markers, these may be used as a screening tool for the early detection of cancer in smokeless tobacco users.

Salivary L-fucose as a biomarker for oral potentially malignant disorders and oral cancer

Background

The objective of this study was to evaluate the serum and salivary L-fucose in oral potentially malignant disorders (OPMDs) and oral cancer (OC) in order to investigate the possibility of using this as biomarker for early diagnosis.

Materials and Methods

The study included 85 participants, who were grouped as control (30), OPMDs patients (25), and OC patients (30). Serum and unstimulated whole saliva were collected from participants of all groups and fucose estimation was done using spectrophotometry. The results were tabulated and analyzed statistically.

Results

The mean serum L-fucose levels in normal, OPMDs, and OC group were 3.49, 19.18, and 35.75 mg/dl, respectively, while the levels of salivary L-fucose were 3.18, 7.02, and 11.66 mg/dl, respectively. A highly significant rise (P < 0.001) in serum and salivary L-fucose was observed in the study participants compared to control.

Conclusions

The present study showed a significant and gradual increase in serum and salivary L-fucose from control to OPMDs to OC. From this study, we suggest that L-fucose can be used as a reliable biomarker and saliva can be used as a diagnostic fluid for screening and early detection of OC.

Serum N-Glycome analysis reveals pancreatic cancer disease signatures

Background &Aims

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer type with loco‐regional spread that makes the tumor surgically unresectable. Novel diagnostic tools are needed to improve detection of PDAC and increase patient survival. In this study we explore serum protein N‐glycan profiles from PDAC patients with regard to their applicability to serve as a disease biomarker panel.

Methods

Total serum N‐glycome analysis was applied to a discovery set (86 PDAC cases/84 controls) followed by independent validation (26 cases/26 controls) using in‐house collected serum specimens. Protein N‐glycan profiles were obtained using ultrahigh resolution mass spectrometry and included linkage‐specific sialic acid information. N‐glycans were relatively quantified and case‐control classification performance was evaluated based on glycosylation traits such as branching, fucosylation, and sialylation.

Results

In PDAC patients a higher level of branching (OR 6.19, P‐value 9.21 × 10⁻¹¹) and (antenna)fucosylation (OR 13.27, P‐value 2.31 × 10⁻⁹) of N‐glycans was found. Furthermore, the ratio of α2,6‐ vs α2,3‐linked sialylation was higher in patients compared to healthy controls. A classification model built with three glycosylation traits was used for discovery (AUC 0.88) and independent validation (AUC 0.81), with sensitivity and specificity values of 0.85 and 0.71 for the discovery set and 0.75 and 0.72 for the validation set.

Conclusion

Serum N‐glycome analysis revealed glycosylation differences that allow classification of PDAC patients from healthy controls. It was demonstrated that glycosylation traits rather than single N‐glycan structures obtained in this clinical glycomics study can serve as a basis for further development of a blood‐based diagnostic test.

Down-regulation of SLC35C1 induces colon cancer through over-activating Wnt pathway

The canonical Wnt signalling pathway is a critical pathway involved in the proliferation of cells. It has been well-established that it plays the central role during colorectal carcinogenesis and development. Yet the exact molecular mechanism of how the canonical Wnt pathway is fine-tuned remains elusive. We found that SLC35C1, a GDP-fucose transporter, negatively regulates the Wnt signalling pathway. We show here that SLC35C1 is reduced in all colon cancer by both immunohistochemistry images and TCGA data, whereas β-catenin is increased. Down-regulation of SLC35C1 is also detected by real-time PCR in stage 3 and stage 4 colorectal cancer tissues. Moreover, analysing the TCGA database with cBioPortal reveals the negative correlation of SLC35C1 mRNA level to the expression of β-catenin. Reduced SLC35C1 significantly promotes cell proliferation and colony formation of HEK293 cells. Meanwhile, in HEK293 cells silencing SLC35C1 activates canonical Wnt pathway, whereas overexpressing SLC35C1 inhibits it. Consistently, the reduction of SLC35C1 in HEK293 cells also elevated the mRNA level of Wnt target genes C-myc, Axin2 and Cyclin D1, as well as the secretion of Wnt3a. In conclusion, we identified SLC35C1 as a negative regulator of the Wnt signalling pathway in colon cancer. Decreased SLC35C1 may cause over-activation of Wnt signalling in colorectal cancer.

Increase of MAL-II Binding Alpha2,3-Sialylated Glycan Is Associated with 5-FU Resistance and Short Survival of Cholangiocarcinoma Patients

Background and objectives: Sialylation plays important roles in tumor progression. Our present study aimed to demonstrate the alteration of sialylation and its role in cholangiocarcinoma (CCA). Materials and Methods: The α2,3- and α2,6-sialylation in CCA tissue was analyzed by lectin-histochemistry using Maackia amurensis lectin-II (MAL-II) and Sambucus nigra agglutinin (SNA). CCA cell lines were treated with the pan-sialylation inhibitor 3Fax-peracetyl-Neu5Ac (3F-Sia) followed by proliferation and chemosensitivity assays. Results: MAL-II binding α2,3-Sialylated Glycan (MAL-SG) and SNA binding α2,6-Sialylated Glycan (SNA-SG) were both elevated in CCA compared with hyperplastic/dysplastic (HP/DP) and normal bile ducts (NBD). The positive staining for MAL-SG or SNA-SG were found in 82% (61/74) of the CCA cases. Higher expression of MAL-SG in CCA was associated with shorter survival of the patients. The median survival of patients with high and low MAL-SG were 167 and 308 days, respectively, with overall survival of 233 days, suggesting the involvement of MAL-SG in CCA progression. MAL-SG expression of CCA cell lines was markedly decreased after treatment with 3F-Sia for 48 to 72 h. While proliferation of CCA cells were not affected by 3F-Sia treatment, their susceptibility to 5-fluorouracil (5-FU) was significantly enhanced. These results suggest that sialylation is involved in the development of 5-FU resistance and the sialylation inhibitor 3F-Sia can be used as a chemosensitizer for CCA. Conclusions: Sialylation is critically involved in the development of chemoresistance of CCA, and sialylation inhibitors may be used as a chemosensitizer in CCA treatment.

Terminal fucose mediates progression of human cholangiocarcinoma through EGF/EGFR activation and the Akt/Erk signaling pathway

Aberrant glycosylation is recognized as a cancer hallmark that is associated with cancer development and progression. In this study, the clinical relevance and significance of terminal fucose (TFG), by fucosyltransferase-1 (FUT1) in carcinogenesis and progression of cholangiocarcinoma (CCA) were demonstrated. TFG expression in human and hamster CCA tissues were determined using Ulex europaeus agglutinin-I (UEA-I) histochemistry. Normal bile ducts rarely expressed TFG while 47% of CCA human tissues had high TFG expression and was correlated with shorter survival of patients. In the CCA-hamster model, TFG was elevated in hyperproliferative bile ducts and gradually increased until CCA was developed. This evidence indicates the involvement of TFG in carcinogenesis and progression of CCA. The mechanistic insight was performed in 2 CCA cell lines. Suppression of TFG expression using siFUT1 or neutralizing the surface TFG with UEA-I significantly reduced migration, invasion and adhesion of CCA cells in correlation with the reduction of Akt/Erk signaling and epithelial-mesenchymal transition. A short pulse of EGF could stimulate Akt/Erk signaling via activation of EGF-EGFR cascade, however, decreasing TFG using siFUT1 or UEA-I treatment reduced the EGF-EGFR activation and Akt/Erk signaling. This evidence provides important insight into the relevant role and molecular mechanism of TFG in progression of CCA.

Is Salivary Sialic Acid a Reliable Biomarker in the Detection of Oral Potentially Malignant Disorder and Oral Squamous Cell Carcinoma

Purpose

Glycoprotein is an important constituent of saliva, and the observed increase in salivary glycoproteins such as sialic acid in oral potentially malignant disorder (OPMDs) and OSCC has stimulated the interest of researchers to explore it as a possible biomarker.

Methods

The study used 60 subjects, who were divided into three groups: Group I-20 subjects who were clinically and histopathologically diagnosed with OSCC; Group II-20 subjects who were clinically and histopathologically diagnosed with OPMDs; and Group III-20 healthy subjects with good oral hygiene and with no systemic disorders detected. Two millilitres of unstimulated salivary samples was collected in a pre-sterilized container to analyse total salivary sialic acid (TSA) levels using a sialic acid kit and UV spectrophotometer.

Results

The TSA levels in OSCC (545.45 ± 100.04) were much higher when compared to the level in OPMDs (169.80 ± 66.43) and in healthy subjects (25.45 ± 16.07). Statically significant correlation was observed between different grades of OSCC. Moreover, sialic acid showed 100% sensitivity and specificity between all the three groups. Statistical analysis was done with Kruskal-Wallis, followed by Mann-Whitney post hoc test at P < 0.05. The results suggested the utility of sialic acid as an efficient biomarker.

The Diverse Contributions of Fucose Linkages in Cancer

Fucosylation is a post-translational modification of glycans, proteins, and lipids that is responsible for many biological processes. Fucose conjugation via α(1,2), α(1,3), α(1,4), α(1,6), and O'- linkages to glycans, and variations in fucosylation linkages, has important implications for cancer biology. This review focuses on the roles that fucosylation plays in cancer, specifically through modulation of cell surface proteins and signaling pathways. How L-fucose and serum fucosylation patterns might be used for future clinical diagnostic, prognostic, and therapeutic approaches will be discussed.

Ascites from Ovarian Cancer Induces Novel Fucosylated Proteins

Ovarian cancer is considered to be the most lethal type of gynecological cancer. During the advanced stages of ovarian cancer, an accumulation of ascites is observed. Fucosylation has been classified as an abnormal post-translational modification that is present in many diseases, including ovarian cancer. Ovarian cancer cells that are cultured with ascites stimulation change their morphology; concomitantly, the fucosylation process is altered. However, it is not known which fucosylated proteins are modified. The goal of this work was to identify the differentially fucosylated proteins that are expressed by ovarian cancer cell lines that are cultured with ovarian cancer patients' ascites. Aleuria aurantia lectin was used to detect fucosylation, and some changes were observed, especially in the cell membrane. Affinity chromatography and mass spectrometry (MALDI-TOF) were used to identify 6 fucosylated proteins. Four proteins (Intermediate filament family orphan 1 [IFFO1], PHD finger protein 20-like protein 1 [PHF20L1], immunoglobulin gamma 1 heavy chain variable region partial [IGHV1-2], and Zinc finger protein 224 [ZNF224]) were obtained from cell cultures stimulated with ascites, and the other two proteins (Peregrin [BRPF1] and Dystrobrevin alpha [DTNA]) were obtained under normal culture conditions. The fucosylated state of some of these proteins was further analyzed. The experimental results show that the ascites of ovarian cancer patients modulated the fucosylation process. The PHD finger protein 20-like protein 1, Zinc finger protein 224 and Peregrin proteins colocalize with fucosylation at different levels.

Serum fucose level in oral cancer, leukoplakia, and oral sub mucous fibrosis: A biochemical study

AIMS

To estimate the serum fucose levels in clinically and histopathologically diagnosed oral cancer, oral leukoplakia, and oral submucous fibrosis cases. To compare and correlate the severity of dysplasia or histopathological grading of the premalignant and malignant lesions with serum fucose levels.

OBJECTIVE

To determine the role of serum fucose as a reliable biomarker for early detection of malignant transformation of potentially malignant lesions and conditions and prediction of biologic behavior of the malignant lesions.

MATERIAL AND METHOD

The intended study shall include 100 participants divided into 4 groups. Groups I, II, and III will include 25 clinically and histological diagnosed cases of oral leukoplakia, oral submucous fibrosis, and oral cancer, and 25 normal control group. Fucose was measured according to the method of Dische and Shettles as adopted by Winzler.

STATISTICAL ANALYSIS

Statistical analysis will be done using SPSS statistical software (Version 10), and the levels of significance will be analyzed using the paired and unpaired t-tests.

RESULT

In subjects of 4 groups were age- and gender-matched and comparable thus these may also not influence the study outcome measure (fucose levels). ANOVA revealed significantly different fucose levels among the groups (F = 17.00, P < 0.001). Mean fucose level did not differ (P > 0.05) between oral leukoplakia, oral submucous fibrosis, and oral cancer (84.5%) groups. The increase in mean fucose levels with severity was the highest in the oral cancer group followed by oral submucous fibrosis and oral leukoplakia group. The mean fucose levels did not differ between mild and moderate grades (P > 0.05) in all the 3 groups.

CONCLUSION

The evaluation of serum l-fucose would be of good help in assessing early malignant change in increasing the accuracy of clinical diagnosis and also in assessing the spread and invasiveness of oral cancer, oral submucous fibrosis, and leukoplakia.

Salivary N-glycosylation as a biomarker of oral cancer: A pilot study

Reliable biomarkers for oral cancer (OC) remain scarce, and routine tests for the detection of precancerous lesions are not routine in the clinical setting. This study addresses a current unmet need for more sensitive and quantitative tools for the management of OC. Whole saliva was used to identify and characterize the nature of glycans present in saliva and determine their potential as OC biomarkers. Proteins obtained from whole saliva were subjected to PNGase F enzymatic digestion. The resulting N-glycans were analyzed with weak anion exchange chromatography, exoglycosidase digestions coupled to ultra-high performance liquid chromatography and/or mass spectrometry. To determine N-glycan changes, 23 individuals with or without cancerous oral lesions were analyzed using Hydrophilic interaction ultra performance liquid chromatography (HILIC–UPLC), and peak-based area relative quantitation was performed. An abundant and complex salivary N-glycomic profile was identified. The main structures present in saliva were neutral oligosaccharides consisting of high mannose, hybrid and complex structures, followed by smaller fractions of mono and di-sialylated structures. To determine if differential N-glycosylation patterns distinguish between OC and control groups, Mann–Whitney testing and principle component analysis (PCA) were used. Eleven peaks were shown to be statistically significant (P ≤ 0.05), while PCA analysis showed segregation of the two groups based on their glycan profile. N-glycosylation changes are active in the oral carcinogenic process and may serve as biomarkers for early detection to reduce morbidity and mortality. Identifying which N-glycans contribute most in the carcinogenic process may lead to their use in the detection, prognosis and treatment of OC.

Mapping human N-linked glycoproteins and glycosylation sites using mass spectrometry

N-linked glycoprotein is a highly interesting class of proteins for clinical and biological research. Over the last decade, large-scale profiling of N-linked glycoproteins and glycosylation sites from biological and clinical samples has been achieved through mass spectrometry-based glycoproteomic approaches. In this paper, we reviewed the human glycoproteomic profiles that have been reported in more than 80 individual studies, and mainly focused on the N-glycoproteins and glycosylation sites identified through their deglycosylated forms of glycosite-containing peptides. According to our analyses, more than 30,000 glycosite-containing peptides and 7,000 human glycoproteins have been identified from five different body fluids, twelve human tissues (or related cell lines), and four special cell types. As the glycoproteomic data is still missing for many organs and tissues, a systematical glycoproteomic analysis of various human tissues and body fluids using a uniform platform is still needed for an integrated map of human N-glycoproteomes.

Glycoproteomic identification of novel plasma biomarkers for oral cancer

Oral cancer with high incidence rates is occurring in many countries including in India, Pakistan, Bangladesh, Sri Lanka and Taiwan. Smoking, alcoholism, and betel nut chewing are considered to be the main risk factors for oral cancer. Further, deaths from oral cancer have increased year by year. Although several oral cancer-associated biomarkers have been reported, very few useful biomarkers have been applied for early diagnosis. Therefore, the investigation of oral cancer-specific biomarkers is urgently needed. We previously investigated N-glycomes of oral cancer cells and patient plasma. We found that both mRNA levels of FUT8 and core-fucosylated glycoproteins increase in cases of oral cancer relative to normal cases. In this study we aim to discover novel core-fucosylated glycoprotein biomarkers for oral cancer diagnosis with glycoproteomic approaches. First, forty plasma samples obtained from the Human Bioinformation Bank of NCKUH were subjected to AAL (Aleuria aurantia lectin) affinity chromatography. Core-fucosylated proteins were collected and applied for LC-MS/MS followed by electrophoresis. Fourteen proteins were identified, and expression levels of proteins in plasma were verified by western blot. Expression levels of some glycoproteins were elevated in the oral cancer group, including ceruloplasmin, haptoglobin, and leucin-rich alpha-2-glycoprotein 1 (LRG1). However, levels of some glycoproteins decreased in the cancer group, including apolipoprotein A-I (apo A-I) and apolipoprotein A-IV (apo A-IV). Via ELISA analysis, we found that apo A-IV and apo A-IV/total protein ratios were decreased in plasma accompanied with cancer stages. The LRG1/total protein ratio was found to increase while plasma levels of LRG1 were not found to differ between the oral cancer plasma and normal groups. An ROC curve analysis reveals strong diagnosis performance when combining apo A-IV levels and LRG1/total protein ratios. Taken together, apo A-IV and LRG1, given their strong performance in detecting oral cancer, can serve as useful biomarkers and may be used as a useful tool for oral cancer screening and early diagnosis.

Role of aberrant glycosylation enzymes in oral cancer progression

BACKGROUND:

Carcinogenesis, a multistep process involves sequential changes during neoplastic transformation. The various hallmarks of cancer aid in cell survival, proliferation, and dissemination. Aberrant glycosylation, a recently defined hallmark of cancer, is influenced by glycosylation enzymes during carcinogenesis. Therefore, the present study measured α-2,3 and α-2,6 sialyltransferase (ST), sialidase, and α-L-fucosidase activity in patients with oral precancerous conditions (OPC) and oral cancer patients.

SUBJECTS:

The study enrolled 100 oral cancer patients, 50 patients with OPC, 100 healthy controls, and 46 posttreatment follow-ups of oral cancer patients. Blood and saliva were collected from all the participants.

MATERIALS AND METHODS:

Sialidase activity was measured by spectrofluorimetric method, α-2,3 and α-2,6 ST by ELISA using biotinylated lectins, and α-L-fucosidase by spectrophotometric method.

RESULTS:

The results depicted increased levels of sialidase, α-2,3 and α-2,6 ST, α-L-fucosidase in patients with OPC and oral cancer patients. Receiver operating characteristic curve indicated significant discriminatory efficacy in distinguishing controls and oral cancer patients for serum and salivary sialidase and α-L-fucosidase activity, and serum α-2,6 ST. Furthermore, serum and salivary α-L-fucosidase activity and serum sialidase activity significantly distinguished controls and patients with OPC. Serum and salivary sialidase, α-L-fucosidase, and serum α-2,3 ST activity were higher in patients with metastasis as compared to nonmetastatic patients. Higher values of serum α-L-fucosidase activity were significantly associated with low-overall survival.

CONCLUSION:

The increased levels of enzymes correlated with tumor initiation, progression, and metastasis in oral cancer patients. The alterations in glycosyltransferases/glycosidases thus support the view of glycosylation as a hallmark of cancer.

Potential role of nuclear magnetic resonance spectroscopy to identify salivary metabolite alterations in patients with head and neck cancer

The analysis of the salivary metabolomic profile may offer an early phase approach to assess the changes associated with a wide range of diseases including head and neck cancer. The aim of the present study was to investigate the potential of nuclear magnetic resonance (NMR) spectroscopy for detecting the salivary metabolic changes associated with head and neck squamous cell carcinoma (HNSCC). Unstimulated whole-mouth saliva samples collected from HNSCC patients (primary tumour was located either in the larynx or in the oral cavity) and healthy controls were analysed by ¹H-NMR spectroscopy. Reliably identified salivary metabolites were quantified and the determined concentration values were compared group-wise using a Mann-Whitney U-test. Multivariate discrimination function analysis (DFA) was conducted to identify such a combination of metabolites, when considered together, that gives maximum discrimination between the groups. HNSCC patients exhibited significantly increased concentrations of 1,2-propanediol (P=0.032) and fucose (P=0.003), while proline levels were significantly decreased (P=0.043). In the DFA model, the most powerful discrimination was achieved when fucose, glycine, methanol and proline were considered as combined biomarkers, resulting in a correct classification rate of 92.1%, sensitivity of 87.5% and specificity of 93.3%. To conclude, NMR spectrometric analysis was revealed to be a feasible approach to study the metabolome of saliva that is sensitive to metabolic changes in HNSCC and straightforward to collect in a non-invasive manner. Salivary fucose was of particular interest and therefore, controlled longitudinal studies are required to assess its clinical relevance as a diagnostic biomarker in HNSCC.

Serum N-glycome characterization and anti-carbohydrate antibody profiling in oral squamous cell carcinoma patients

Glycosylation is a protein post translational modification which plays important role in protein function, stabilization, trafficking, and turnover. Alteration of protein glycosylation is a common phenomenon during tumor progression, migration, invasion, angiogenesis, as well as metastasis. Hence, aberrant glycan structures and the induced corresponding anti-carbohydrate antibodies are potential biomarkers for cancer diagnosis. In this study, serum N-glycomes and anti-carbohydrate antibodies from normal populations and oral squamous cell carcinoma (OSCC) patients were investigated. Total serum proteins were lyophilized and subjected to chemical reduction, alkylation and trypsin digestion. The N-glycans were released, purified, permethylated, and analyzed using MALDI-TOF-Mass spectrometry. In addition, the serum anti-carbohydrate antibody profiles were also investigated by carbohydrate microarray. We found that the relative abundances of seven N-glycans were decreased or increased in serum of OSCC with diagnostic accuracy greater than 75%. The relative abundances of total tri-antennary and tetra-antennary glycans with varying degrees of fucosylation and sialylation were also increased in serum N-glycomes of OSCC. In an independent validation group of forty-eight OCCC patients, most of the high-molecular weight serum N-glycans showed significantly high sensitivity and specificity according to the identified cutoff values. Furthermore, the serum levels of two IgM antibodies were elevated accompanied with the decreased levels of nine IgG antibodies in patient serum. Taken together, these serum N-glycans and antibodies identified in this study should be considered as the candidates of potential biomarkers for OSCC diagnosis.

Correlation of serum levo-fucose levels as a biomarker with tumor node metastasis staging in oral cancer patients

Background:

oral cancer is a result of disordered cellular behavior initiated by various stimuli which is characterized by the alteration of serum glycoproteins consisting of different monosaccharides. One of these is levo-fucose (L-fucose), a methyl pentose. Elevated levels of protein-bound fucose have been reported in various malignancies.

Aim:

The present study attempted to correlate levels of serum L-fucose as a biomarker with the various tumor node metastasis (TNM) stages of oral cancer.

Methodology:

The study was carried out on 90 subjects consisting of 30 healthy controls and 60 histopathologically proven oral squamous cell carcinoma (OSCC) cases. The serum fucose level estimation was done based on the method adopted by Winzler. Statistical analysis included independent sample's t-test, one-way ANOVA test, Karl–Pearson correlation test, and Tukey's HSD post hoc test to evaluate the significance and variability of values between groups.

Results:

Significant elevation in serum fucose levels was noticed among OSCC patients when compared with the controls and a progressive ascent of L-fucose levels were noted as the stage of severity increased. Serum fucose levels were independent of histopathological grading, age, and sex.

Conclusion:

Serum L-fucose levels were increased in OSCC patients, and a positive correlation was observed between serum L-fucose levels and TNM staging of OSCC. Thus, serum L-fucose can be used as an effective diagnostic and prognostic biomarker in OSCC patients.

Pathophysiologic processes have an impact on the plasma metabolomic signature of endometriosis patients

OBJECTIVE

To evaluate potential variations in the plasma metabolomic profile of endometriosis patients as a consequence of pathophysiologic alterations associated with this disorder.

DESIGN

Prospective study. For each subject, a plasma sample was collected after overnight fasting and before surgery.

SETTING

University medical center.

PATIENT(S)

The clinical cohort included 50 endometriosis patients, diagnosed at early (n = 6) and advanced (n = 44) stages of the disease, and 23 healthy women. All volunteers underwent diagnostic laparoscopy to visually confirm the presence or absence of endometriotic lesions.

INTERVENTION(S)

Metabolomic profiling of plasma samples based on ¹H-nuclear magnetic resonance (NMR) spectroscopy in combination with statistical approaches.

MAIN OUTCOME MEASURE(S)

Comparative identification of metabolites present in plasma from endometriosis patients and healthy women.

RESULT(S)

The plasma metabolomic profile of endometriosis patients was characterized by increased concentration of valine, fucose, choline-containing metabolites, lysine/arginine, and lipoproteins and decreased concentration of creatinine compared with healthy women. Metabolic alterations identified in the plasma metabolomic profile of endometriosis patients correlate with pathophysiologic events previously described in the progression of this disease.

CONCLUSION(S)

The results highlight the potential of ¹H-NMR-based metabolomics to characterize metabolic alterations associated with endometriosis in plasma samples. This information could be useful to get a better understanding of the molecular mechanisms involved in the pathogenesis of endometriosis, thus facilitating the noninvasive diagnosis of this pathology at early stages.

Fucose: A biomarker in grading of oral cancer

INTRODUCTION

Early diagnosis of cancer helps a great deal in the management of oral cancer patients. Number of proteinous markers have been employed for this purpose. Majority of them are not specific. Recently conjugated oligosaccharide with proteins and lipids have gained considerable importance in the present postgenomics and postproteomic period in the diagnostic and prognostics of cancer cases.

MATERIALS AND METHODS

In this study, serum fucose levels were estimated in 50 control cases and 75 cases of oral cancer by the method of Dische and Shettles as adopted by Winzler.

RESULTS

Serum fucose levels were found to be significantly higher in oral cancer cases (46.63 ± 5.29 mg/dl) as compared to the control cases (7.22 ± 0.26 mg/dl). The stepwise elevated serum fucose levels were found to be correlated with the histopathological grading of oral cancer.

CONCLUSIONS

Estimation of such fucose conjugated proteins is suggestive to be good biomarkers in the diagnosis of oral cancer cases as well as in assessing the prognosis of such cases.

Intrinsic hepatocyte dedifferentiation is accompanied by upregulation of mesenchymal markers, protein sialylation and core alpha 1,6 linked fucosylation

Alterations in N-linked glycosylation have long been associated with cancer but for the most part, the reasons why have remained poorly understood. Here we show that increased core fucosylation is associated with de-differentiation of primary hepatocytes and with the appearance of markers indicative of a transition of cells from an epithelial to a mesenchymal state. This increase in core fucosylation was associated with increased levels of two enzymes involved in α-1,6 linked fucosylation, GDP-mannose 4, 6-dehydratase (Gmds) and to a lesser extent fucosyltransferase 8 (Fut8). In addition, the activation of cancer-associated cellular signaling pathways in primary rat hepatocytes can increase core fucosylation and induce additional glycoform alterations on hepatocyte proteins. Specifically, we show that increased levels of protein sialylation and α-1,6-linked core fucosylation are observed following activation of the β-catenin pathway. Activation of the Akt signaling pathway or induction of hypoxia also results in increased levels of fucosylation and sialylation. We believe that this knowledge will help in the better understanding of the genetic factors associated with altered glycosylation and may allow for the development of more clinically relevant biomarkers.

Serum total antioxidant capacity in oral carcinoma patients

Context:

Oxidative stress is a major determinant in carcinogenesis and serum total antioxidant capacity (TAC) indirectly reflects the level of oxidative stress. Although oral cancer is the third most frequent cancer in Indian population, there are no standard noninvasive marker for early detection and monitoring therapeutic response in oral cancer patients.

Aims:

This study was carried out to investigate implications of serum TAC in oral cancer by evaluating pre- and post-operative levels in oral cancer patients.

Settings and Designs:

It was a prospective single blinded study.

Subjects and Methods:

Serum TAC was measured using ferric-reducing antioxidant power assay. Pre- and post-operative values were estimated and compared in 30 oral cancer patients who underwent surgery.

Statistical Analysis Used:

Paired t-test was used to compare pre- and post-operative values.

Results:

Compared to the normal value, both pre- and post-operative serum TAC were significantly low in oral cancer patients. However, there was no statistically significant difference between pre- and postoperative levels.

Conclusions:

In this study, low mean serum TAC was detected in oral cancer patients. However, its diagnostic and prognostic significance in oral cancer needs further investigation.

Durable remission of renal cell carcinoma in conjuncture with graft versus host disease following allogeneic stem cell transplantation and donor lymphocyte infusion: rule or exception?

Allogeneic stem cell transplantation (alloSCT) followed by donor lymphocyte infusion (DLI) can be applied as immunotherapeutic intervention to treat malignant diseases. Here, we describe a patient with progressive metastatic clear cell renal cell carcinoma (RCC) who was treated with T cell depleted non-myeloablative alloSCT and DLI resulting in disease regression accompanied by extensive graft versus host disease (GVHD). We characterized the specificity of this immune response, and detected a dominant T cell population recognizing a novel minor histocompatibility antigen (MiHA) designated LB-FUCA2-1V. T cells specific for LB-FUCA2-1V were shown to recognize RCC cell lines, supporting a dominant role in the graft versus tumor (GVT) reaction. However, coinciding with the gradual disappearance of chronic GVHD, the anti-tumor effect declined and 3 years after alloSCT the metastases became progressive again. To re-initiate the GVT reaction, escalating doses of DLI were given, but no immune response could be induced and the patient died of progressive disease 8.5 years after alloSCT. Gene expression studies illustrated that only a minimal number of genes shared expression between RCC and professional antigen presenting cells but were not expressed by non-malignant healthy tissues, indicating that in patients suffering from RCC, GVT reactivity after alloSCT may be unavoidably linked to GVHD.

Quantitative evaluation and correlation of serum glycoconjugates: Protein bound hexoses, sialic acid and fucose in leukoplakia, oral sub mucous fibrosis and oral cancer

BACKGROUND

Cancer is one of the most common causes of mortality and morbidity today, with more than 10 million new cases and more than 6 million deaths each year worldwide. Globally Oral Cancer is the sixth most common cause of cancer related death. India accounts for 86% of the world's oral cancer cases. Often it proceeds by pre cancerous conditions and lesions. In search for biological markers with diagnostic value, we investigated serum glycoconjugates like protein bound hexoses, fucose and sialic acid in these diseases.

MATERIALS AND METHODS

For this Study 27 newly diagnosed Oral leukoplakia, 27 OSMF and 26 Oral Cancer patients, 40 healthy controls who are non tobacco users and 40 healthy controls who are tobacco users were selected. In all these groups we estimated serum glycoconjugates.

RESULTS

We observed no difference in serum glycoconjugates levels between tobacco and non tobacco controls (P > 0.05), but very high levels in oral cancer, Leukoplakia and oral sub mucous fibrosis (OSMF) patients (P < 0.001) when compared to control groups. Fucose levels were significant (P < 0.05) of all the glycoconjugates between OSMF and Leukoplakia.

CONCLUSION

The serum glycoconjugates whose levels were very high in OSMF, Leukoplakia and Oral Cancer, do have a significant diagnostic and prognostic value in these diseases.

Identification of novel tumor markers for oral squamous cell carcinoma using glycoproteomic analysis

BACKGROUND

Oral cancer, the largest subset of head and neck cancer, has become one of the most lethal malignancies during the last two decades. Although several diagnostic tools have been applied for the early detection of oral malignancies, it is still urgent to identify novel tumor markers. In this study, we explored the cell surface N-glycomes of primary cultured human oral keratinocytes (HOK), immortalized human gingival keratinocytes (SG cells), and oral squamous cell carcinoma (OC2).

METHODS

Enzymatically hydrolyzed cell surface N-glycans were analyzed by MALDI-TOF mass spectrometry.

RESULTS

High levels of fucosylated N-glycans, especially core-fucosylated N-glycans, were observed on the OC2 cell surface whereas the major N-glycans on SG and HOK cells were high mannose type. In addition, the mRNA expression level of fucosyltransferase 8 was elevated significantly in OC2 cells than in SG and HOK cells. Core-fucosylated glycoproteins of OC2 cells were then purified with lectin affinity chromatography and a key adhesion molecule in cancer cells, CD147, was identified. Finally, overexpression of cell surface CD147 was confirmed on OC2 cells and oral cancer tissues (tissue array).

CONCLUSIONS

CD147 was discovered by glycoproteomic approaches and suggested to be a potential novel tumor marker for oral cancer diagnosis.

Glycoprotein electrophoretic patterns have potential to monitor changes associated with neoplastic transformation in oral cancer

Alterations in glycoproteins, important cell surface constituents, have long been associated with various malignancies. The present investigation therefore explored the clinical significance of a glycoproteomics approach in patients with oral precancerous conditions (OPC) and patients with oral cancer. The study included 80 oral cancer patients, 50 patients with OPC, and 84 controls. Native polyacrylamide gel electrophoresis followed by Schiff’s staining was carried out to study the alterations in glycoproteins. The results showed significant elevation (p<0.0001) of 192 kDa, 170 kDa, 116 kDa and 44 kDa glycoproteins in oral cancer patients and patients with OPC compared with controls. The odds ratio indicated a significantly higher risk for oral cancer among users and especially chewers of tobacco. The levels of all the glycoprotein bands (192 kDa, 170 kDa, 116 kDa and 44 kDa) were higher in patients with a habit of tobacco use (WHT) than in patients with no habit of tobacco (NHT) and were also higher in WHT controls than in NHT controls. Moreover, a 230 kDa glycoprotein consistently appeared only in individuals with tobacco habits and an increasing trend was observed from WHT controls to patients with OPC to WHT oral cancer patients. In conclusion, the results indicated the potential utility of glycoprotein alterations in monitoring sequential changes occurring due to tobacco consumption during neoplastic transformation.

Iminosugar-ferrocene conjugates as potential anticancer agents

We prepared a series of new iminosugar-ferrocene hybrids displaying potent inhibition of fucosidase (bovine kidney) and inactivation of MDA-MB-231 breast cancer cells proliferation at low micromolar concentrations. The synthetic route brought to light an unprecedented isomerisation of a 2-ethanalylpyrrolidine.

Glycomic and proteomic profiling of pancreatic cyst fluids identifies hyperfucosylated lactosamines on the N-linked glycans of overexpressed glycoproteins

Pancreatic cancer is now the fourth leading cause of cancer deaths in the United States, and it is associated with an alarmingly low 5-year survival rate of 5%. However, a patient's prognosis is considerably improved when the malignant lesions are identified at an early stage of the disease and removed by surgical resection. Unfortunately, the absence of a practical screening strategy and clinical diagnostic test for identifying premalignant lesions within the pancreas often prevents early detection of pancreatic cancer. To aid in the development of a molecular screening system for early detection of the disease, we have performed glycomic and glycoproteomic profiling experiments on 21 pancreatic cyst fluid samples, including fluids from mucinous cystic neoplasms and intraductal papillary mucinous neoplasms, two types of mucinous cysts that are considered high risk to undergo malignant transformation. A total of 80 asparagine-linked (N-linked) glycans, including high mannose and complex structures, were identified. Of special interest was a series of complex N-linked glycans containing two to six fucose residues, located predominantly as substituents on β-lactosamine extensions. Following the observation of these "hyperfucosylated" glycans, bottom-up proteomics experiments utilizing a label-free quantitative approach were applied to the investigation of two sets of tryptically digested proteins derived from the cyst fluids: 1) all soluble proteins in the raw samples and 2) a subproteome of the soluble cyst fluid proteins that were selectively enriched for fucosylation through the use of surface-immobilized Aleuria aurantia lectin. A comparative analysis of these two proteomic data sets identified glycoproteins that were significantly enriched by lectin affinity. Several candidate glycoproteins that appear hyperfucosylated were identified, including triacylglycerol lipase and pancreatic α-amylase, which were 20- and 22-fold more abundant, respectively, following A. aurantia lectin enrichment.

Analysis of the reaction coordinate of alpha-L-fucosidases: a combined structural and quantum mechanical approach

The enzymatic hydrolysis of alpha-L-fucosides is of importance in cancer, bacterial infections, and fucosidosis, a neurodegenerative lysosomal storage disorder. Here we show a series of snapshots along the reaction coordinate of a glycoside hydrolase family GH29 alpha-L-fucosidase unveiling a Michaelis (ES) complex in a (1)C(4) (chair) conformation and a covalent glycosyl-enzyme intermediate in (3)S(1) (skew-boat). First principles metadynamics simulations on isolated alpha-L-fucose strongly support a (1)C(4)<-->(3)H(4)<-->(3)S(1) conformational itinerary for the glycosylation step of the reaction mechanism and indicate a strong "preactivation" of the (1)C(4) complex to nucleophilic attack as reflected by free energy, C1-O1/O5-C1 bond length elongation/reduction, C1-O1 bond orientation, and positive charge development around the anomeric carbon. Analysis of an imino sugar inhibitor is consistent with tight binding of a chair-conformed charged species.

Nontargeted urinary metabolite profiling of a mouse model of Crohn's disease

Crohn's disease is an inflammatory disorder of the bowel, believed to arise from the dysregulation of intestinal mucosal immunity. The interleukin-10-deficient (IL10-/-) mouse, which develops intestinal inflammation in the presence of gut microflora, serves as a mouse model of Crohn's disease. Nontargeted urinary metabolite profiling was carried out to identify systemic metabolic changes associated with the development of intestinal inflammation caused by IL10-deficiency. Spot urine samples, collected from IL10-/- and wildtype mice at ages 5.5, 7, 8.5, and 10.5 weeks old were analyzed by gas chromatography-mass spectrometry (GCMS). The data were analyzed using XCMS software, multiple t tests, and ANOVA. Among the key metabolic differences detected were elevated urinary levels of xanthurenic acid and fucose in IL10-/- mice relative to wildtype, indicating upregulation of tryptophan catabolism and perturbed fucosylation in IL10-/- mice. Three short-chain dicarboxylic acid metabolites were decreased in urine of IL10-/- mice relative to wildtype, suggesting the downregulation of fatty acid oxidation in IL10-/- mice. These metabolic differences were reproducible in an independent set of mice. This study demonstrates that nontargeted GCMS metabolite profiling of IL10-/- mice can provide insights into the metabolic effects of IL10-deficiency and identify potential markers of intestinal inflammation.

Identification of predictive biomarkers for response to trastuzumab using plasma FUCA activity and N-glycan identified by MALDI-TOF-MS

The aim of this study was to identify glycobiological biomarkers that indicate sensitivity to trastuzumab, a humanized monoclonal antibody against HER2 in plasma samples from breast cancer patients. Plasma samples were obtained from 24 breast cancer patients treated with trastuzumab monotherapy. The catalytic activities of plasma alpha1-6, fucosyltransferase (FUT8) and alpha-L fucosidase (FUCA) were analyzed using high-performance liquid chromatography (HPLC) and spectrophotometer, respectively. The plasma N-glycan profiles were investigated using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Plasma FUT8 activity was not significantly correlated with either the clinical response or progression-free survival (PFS). On the other hand, plasma FUCA activity was significantly correlated with PFS (p < 0.05). The MALDI-TOF-MS analysis of the plasma N-glycan profile revealed that the expression of 2534 m/z N-glycan was lower in patients with progressive disease (PD) and was correlated with PFS. Low expression of 2534 m/z N-glycan discriminated between PD and non-PD with 75% sensitivity and 82% specificity. We demonstrated that the plasma FUCA activity and 2534 m/z N-glycan may be predictive biomarkers of sensitivity to trastuzumab. Our results suggest that glycosylation analysis may provide useful information for determining clinical cancer therapy and provide novel insight into biomarker studies using glycobiological tools in the field of breast cancer.