Changes in blood microbiota profiles associated with liver fibrosis in obese patients: A pilot analysis.

The early detection of liver fibrosis among patients with nonalcoholic fatty liver disease (NAFLD) is an important clinical need. In view of the suggested role played by bacterial translocation in liver disease and obesity, we sought to investigate the relationship between blood microbiota and liver fibrosis (LF) in European cohorts of patients with severe obesity. We carried out a cross-sectional study of obese patients, well characterized with respect to the severity of the NAFLD, in the cohort FLORINASH. This cohort has been divided into a discovery cohort comprising 50 Spanish patients and then in a validation cohort of 71 Italian patients. Blood bacterial DNA was analyzed both quantitatively by 16S ribosomal DNA (rDNA) quantitative polymerase chain reaction and qualitatively by 16S rDNA targeted metagenomic sequencing and functional metagenome prediction. Spanish plasma bile acid contents were analyzed by liquid chromatography/mass spectrometry. The 16S rDNA concentration was significantly higher in patients of the discovery cohort with LF. By 16S sequencing, we found specific differences in the proportion of several bacterial taxa in both blood and feces that correlate with the presence of LF, thus defining a specific signature of the liver disease. Several secondary/primary bile acid ratios were also decreased with LF in the discovery cohort. We confirmed, in the validation cohort, the correlation between blood 16S rDNA concentration and LF, whereas we did not confirm the specific bacterial taxa signature, despite a similar trend in patients with more-severe fibrosis. CONCLUSION: Changes in blood microbiota are associated with LF in obese patients. Blood microbiota analysis provides potential biomarkers for the detection of LF in this population. (Hepatology 2016;64:2015-2027).

Correlation between mutational status and survival and second cancer risk assessment in patients with gastrointestinal stromal tumors: a population-based study.

BACKGROUND: Gastrointestinal stromal tumors are sarcomas of the digestive tract characterized by mutations mainly located in the c-KIT or in the platelet-derived growth factor receptor (PDGFR)-alpha genes. Mutations in the BRAF gene have also been described. Our purpose is to define the distribution of c-KIT, PDGFR and BRAF mutations in a population-based cohort of gastrointestinal stromal tumors (GIST) patients and correlate them with anatomical site, risk classification and survival. In addition, as most of the GIST patients have a long survival, second cancers are frequently diagnosed in them. We performed a second primary cancer risk assessment. METHODS: Our analysis was based on data from Tarragona and Girona Cancer Registries. We identified all GIST diagnosed from 1996 to 2006 and performed a mutational analysis of those in which paraffin-embedded tissue was obtained. Observed (OS) and relative survival (RS) were calculated according to risk classifications and mutational status. Multivariate analysis of variables for observed survival and was also done. RESULTS: A total of 132 GIST cases were found and we analyzed mutations in 108 cases. We obtained 53.7% of mutations in exon 11 and 7.4% in exon 9 of c-KIT gene; 12% in exon 18 and 1.9% in exon 12 of PDGFR gene and 25% of cases were wild type GIST. Patients with mutations in exon 11 of the c-KIT gene had a 5-year OS and RS of 59.6% and 66.3%, respectively. Patients with mutations in exon 18 of the PDGFR gene had a 5-year OS and RS of 84.6% and 89.7%. In multivariate analysis, only age and risk group achieved statistical significance for observed survival. GIST patients had an increased risk of second cancer with a hazard ratio of 2.47. CONCLUSIONS: This population-based study shows a spectrum of mutations in the c-KIT and PDGFR genes in GIST patients similar to that previously published. The OS and RS of GIST with the exon 18 PDGFR gene mutation could indicate that this subgroup of patients may be less aggressive and have a good prognosis, although less sensitive to treatment at recurrence. In our study, GIST patients have an increased risk of developing a second neoplasm.

Exploring the Associations of Inflammatory and Oxidative Stress Biomarkers with Pancreatic Diseases: An Observational and Mendelian Randomisation Study.

Identifying biomarkers linked to pancreatic ductal adenocarcinoma (PDAC) and chronic pancreatitis (CP) is crucial for early detection, treatment, and prevention. Methods: Association analyses of 10 serological biomarkers involved in cell signalling (IFN-γ, IL-6, IL-8, IL-10), oxidative stress (superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzyme activities, total glutathione (GSH), malondialdehyde (MDA) levels), and intestinal permeability proteins (zonulin, I-FABP2) were conducted across PDAC (n = 12), CP (n = 21) and control subjects (n = 23). A Mendelian randomisation (MR) approach was used to assess causality of the identified significant associations in two large genetic cohorts (FinnGen and UK Biobank). Results: Observational results showed a downregulation of SOD and GPx antioxidant enzyme activities in PDAC and CP patients, respectively, and higher MDA levels in CP patients. Logistic regression models revealed significant associations between CP and SOD activity (OR = 0.21, 95% CI [0.05, 0.89], per SD), GPx activity (OR = 0.28, 95% CI [0.10, 0.79], per SD), and MDA levels (OR = 2.05, 95% CI [1.36, 3.08], per SD). MR analyses, however, did not support causality. Conclusions: These findings would not support oxidative stress-related biomarkers as potential targets for pancreatic diseases prevention. Yet, further research is encouraged to assess their viability as non-invasive tools for early diagnosis, particularly in pre-diagnostic CP populations.

Characterization of Mesothelin Glycosylation in Pancreatic Cancer: Decreased Core Fucosylated Glycoforms in Pancreatic Cancer Patients' Sera.

Currently, there are no reliable biomarkers for the diagnosis of pancreatic cancer (PaC). Glycoproteomic approaches that analyze the glycan determinants on specific glycoproteins have proven useful to develop more specific cancer biomarkers than the corresponding protein levels. In PaC, mesothelin (MSLN) is a neo-expressed glycoprotein. MSLN glycosylation has not been described and could be altered in PaC. In this work, we aimed to characterize MSLN glycans from PaC cells and serum samples to assess their potential usefulness as PaC biomarkers. First, we analyzed MSLN glycans from PaC cell lines and then we developed an enzyme-linked lectin assay to measure core fucosylated-MSLN (Cf-MSLN) glycoforms. MSLN glycans from PaC cells were analyzed by glycan sequencing and through Western blotting with lectins. All of the cell lines secreted MSLN, with its three N-glycosylation sites occupied by complex-type N-glycans, which were mainly α2,3-sialylated, core fucosylated and highly branched. The Cf-MSLN glycoforms were quantified on PaC serum samples, and compared with MSLN protein levels. The Cf-MSLN was significantly decreased in PaC patients compared to control sera, while no differences were detected by using MSLN protein levels. In conclusion, Cf-MSLN glycoforms were differently expressed in PaC, which opens the way to further investigate their usefulness as PaC biomarkers.

Microfibril associated protein 4 (MFAP4) is a carrier of the tumor associated carbohydrate sialyl-Lewis x (sLex) in pancreatic adenocarcinoma.

Late diagnosis of pancreatic ductal adenocarcinoma (PDA) is one of the reasons of its low 5-year survival rate and it is due to its unspecific symptoms during the first stages of the disease and the lack of reliable serological markers. Since PDA shows an altered glycan expression, here we have focused on finding novel potential biomarkers, namely glycoproteins that express the tumor associated carbohydrate structure sialyl-Lewis x (sLex), which is described in PDA. Through a glycoproteomic approach, we have analyzed target proteins containing sLex from PDA tissues by 2DE and immunodetection techniques, and have identified by mass spectrometry the protein MFAP4 as a carrier of sLex in PDA. MFAP4 showed a higher expression in PDA tissues compared with pancreatic control tissues. In addition, the colocalization of sLex over MFAP4 was found only in PDA and not in control pancreatic tissues. The analysis of MFAP4 expression in PDA cell lines and their secretome, in combination with immunohistochemistry of pancreatic tissues, revealed that MFAP4 was not produced by PDA cells, but it was found in the pancreatic extracellular matrix. The specificity of MFAP4 glycoform containing sLex in PDA tissues shows its relevance as a potential PDA biomarker. SIGNIFICANCE: Despite advances in the field of cancer research, pancreatic ductal adenocarcinoma (PDA) lacks of a specific and sensitive biomarker for its early detection, when curative resection is still possible before metastases arise. Thus, efforts to discover new PDA biomarkers represent the first line in the fight against the increase of its incidence reported in recent years. Glycan alterations on glycoconjugates, such as glycoproteins have emerged as a rich source for the identification of novel cancer markers. In the present work, we aimed to shed light on novel biomarkers based on altered glycosylation in PDA, in particular those glycoproteins of PDA tissues carrying the tumor carbohydrate antigen sialyl-Lewis x (sLex). Through a glycoproteomic approach, we have shown that the glycoprotein MFAP4 carries sLex in PDA tissues and not in control pancreatic tissues. MFAP4 is found in the extracellular matrix in PDA and although its role in cancer progression is unclear, its sLex glycoform could be a potential biomarker in pancreatic ductal adenocarcinoma.

Quantitative structure-retention relationships applied to liquid chromatography gradient elution method for the determination of carbonyl-2,4-dinitrophenylhydrazone compounds.

A usual method for the determination of aldehydes and ketones in different matrices consists of a derivatization with 2,4-dinitrophenylhydrazine (DNPH) followed by HPLC-UV analysis. In the present work, a HPLC-UV gradient elution method has been applied to the analysis of 13 aldehydes and ketones-DNPH in automotive emission samples. In addition to these 13 compounds-DNPH, several carbonyl-DNPH compounds (linear, ramified and cyclic, saturated and unsaturated compounds) have been analyzed by HPLC-UV. Quantitative structure-retention relationships (QSRR) methods have been applied to predict the logarithm of capacity factor (logk') of carbonyl-DNPH compounds. According to its physicochemical meaning, combinations of 2 and 3 molecular descriptors have been proposed in order to achieve higher correlation with logk'. Using linear and non-linear QSRR methodologies, the resulting prediction models allowed the screening of the most probable carbonyl-DNPH derivative candidates that correspond to unknown compounds detected in automotive emission samples. This information has been useful for their identification by UPLC(®)-MS/MS. In addition, the chromatographic retention of different carbonyl-DNPH compound families was studied using two HPLC isocratic methods working with two orthogonal stationary phases (octadecylpolyethoxysilane and cyanopropyl). Differences between the retention indexes obtained for each column were used for classifying carbonyl-DNPH into compounds families.