High levels of aromatic amino acids in gastric juice during the early stages of gastric cancer progression.

BACKGROUND: Early-stage gastric cancer is mostly asymptomatic and can easily be missed easily by conventional gastroscopy. Currently, there are no useful biomarkers for the early detection of gastric cancer, and their identification of biomarkers is urgently needed. METHODS: Gastric juice was obtained from 185 subjects that were divided into three groups: non-neoplastic gastric disease (NGD), advanced gastric cancer and early gastric cancer (EGC). The levels of aromatic amino acids in the gastric juice were quantitated using high-performance liquid chromatography. RESULTS: The median values (25th to 75th percentile) of tyrosine, phenylalanine and tryptophan in the gastric juice were 3.8 (1.7-7.5) µg/ml, 5.3 (2.3-9.9) µg/ml and 1.0 (0.4-2.8) µg/ml in NGD; 19.4 (5.8-72.4) µg/ml, 24.6 (11.5-73.7) µg/ml and 8.3 (2.1-28.0) µg/ml in EGC. Higher levels of tyrosine, phenylalanine and tryptophan in the gastric juice were observed in individuals of EGC groups compared those of the NGD group (NGD vs. EGC, P<0.0001). For the detection of EGC, the areas under the receiver operating characteristic curves (AUCs) of each biomarker were as follows: tyrosine, 0.790 [95% confidence interval (CI), 0.703-0.877]; phenylalanine, 0.831 (95% CI, 0.750-0.911); and tryptophan, 0.819 (95% CI, 0.739-0.900). The sensitivity and specificity of phenylalanine were 75.5% and 81.4%, respectively, for detection of EGC. A multiple logistic regression analysis showed that high levels of aromatic amino acids in the gastric juice were associated with gastric cancer (adjusted β coefficients ranged from 1.801 to 4.414, P<0.001). CONCLUSION: Increased levels of tyrosine, phenylalanine and tryptophan in the gastric juice samples were detected in the early phase of gastric carcinogenesis. Thus, tyrosine, phenylalanine and tryptophan in gastric juice could be used as biomarkers for the early detection of gastric cancer. A gastric juice analysis is an efficient, economical and convenient method for screening early gastric cancer development in the general population

Non-pylori Helicobacters (NHPHs) Induce Shifts in Gastric Microbiota in Helicobacter pylori-Infected Patients

To explore the effects of gastric non-H. pylori Helicobacter species(NHPH) on the structure and potential function of gastric microbiota, we employed 16S rRNA gene sequencing on 164 gastric biopsy specimens from NHPH (H. suis, H. felis, H. salomonis) /H. pylori coinfection individuals, H. pylori monoinfection individuals and healthy controls. The results demonstrated that marked structural and functional variations between H. pylori mono- and coinfection samples (HPHS, HPHF, HPHM). The changes in bacterial structure induced by NHPH are mainly attributed to their ability of gastric acid secretion inhibition as well as bacterial chemotaxis. Both the HPHS and HPHF groups showed significant increases in phylotype richness and significant decreases in β diversity, but this trend was not found in HPHM group. Regarding the top five phyla and top thirty-five genera, the HPHS and HPHF groups had similar variation trends in relative abundance. The increased relative abundance levels of the genera Vibrio, Pseudoalteromonas, Photobacterium, and Clostridium were associated with increases in predicted signal transduction/metabolic pathways among the three coinfection groups. The relative abundance levels of bacteria involved in the formation of N-nitroso compounds were significantly decreased in the HPHS and HPHF groups (e.g., Streptococcus, Neisseria, Haemophilus, Veillonella, Clostridium, etc.). The significantly decreased relative abundance levels of the phyla Firmicutes and Bacteroidetes in the HPHS and HPHF groups were associated with the observed increases in predicted lipid metabolism pathways. The results in this study implied that NHPH can arouse the variation of structure and function of gastric microbiota, which may pave the way to further research on the pathogenesis of gastric diseases

Effect of 5-Aza-2’-deoxycytidine on immune-associated proteins in exosomes from hepatoma

AIM: To study the effect of 5-Aza-2’-deoxycytidine (5-Aza-CdR) on heat shock protein 70 (HSP70), human leucocyte antigen-I (HLA-I) and NY-ESO-1 proteins in exosomes produced by hepatoma cells, HepG2 and Hep3B

Operating condition for Quantitative HPLC.

a<p>0.05% (v/v) trifluoroacetic acid/water;</p>b<p>pure acetonitrile.</p

The measurement of protein and aromatic amino acids in gastric juice.

a<p>The three groups (NGD, AGC and EGC) were compared using the Kruskal-Wallis test;</p>***<p>Compared with the NGD group using Dunn's test. The <i>P</i> value is less than 0.001;</p>b<p>Comparisons were carried out between AGC and EGC using Dunn's multiple comparison post hoc tests were used. <i>P</i> values were calculated (tyrosine, 0.811; phenylalanine, 0.781; tryptophan, 0.691; protein, 0.044 which is less than the significance level of 0.017).</p