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Table S1. Differentially methylated CpGs of non-clustered PCDHs by H. pylori eradication in the whole-genome methylation profiling. Table S2. The association between major characteristics and methylation of four PCDH genes. Table S3. Associations between DNA methylation levels and expression. Table S4. PCR primers and experiment condition of candidate genes. Details for immunohistochemical staining

Figure S1. Representative pictures of immunohistochemical staining for PCDH10 and PCDH17 (20X) PCDH10 and PCDH17 were expressed in the membrane and cytoplasm of epithelial and some stromal cell. (a, b) Representative pictures of immunohistochemical staining for PCDH10 negative and positive expression. (c, d) Representative pictures of immunohistochemical staining for PCDH17 negative and positive expression.

Background and Aim: Methylation alterations may be involved in Helicobacter pylori-associated gastric carcinogenesis. This study aims to explore the potential H.pylori-associated methylation biomarkers in blood leukocyte and gastric mucosa. Methods: Five candidate H.pylori-associated aberrant methylation genes were selected from the previous genome-wide profiling panels and validated in blood leukocyte and gastric mucosa in multi-stages (case-control validation between H.pylori positive and negative subjects and self-control validation before and after anti-H.pylori treatment). Results: GNAS methylation level was decreased in blood leukocyte (62.07% v.s. 46.33%, p

Background and aim Dietary strategies that contribute to reducing incidence of Helicobacter pylori infection without negative side effects are highly desirable owing to worldwide bacterial prevalence and carcinogenesis potential. The aim of this study was to determine dosage effect of daily cranberry consumption on H. pylori suppression over time in infected adults to assess the potential of this complementary management strategy in a region with high gastric cancer risk and high prevalence of H. pylori infection. Methods This double‐blind, randomized, placebo‐controlled trial on 522 H. pylori‐positive adults evaluated dose–response effects of proanthocyanidin‐standardized cranberry juice, cranberry powder, or their placebos on suppression of H. pylori at 2 and 8 weeks by 13C‐urea breath testing and eradication at 45 days post‐intervention. Results H. pylori‐negative rates in placebo, low‐proanthocyanidin, medium‐proanthocyanidin, and high‐proanthocyanidin cranberry juice groups at week 2 were 13.24%, 7.58%, 1.49%, and 13.85% and at week 8 were 7.35%, 7.58%, 4.48%, and 20.00%, respectively. Consumption of high‐proanthocyanidin juice twice daily (44 mg proanthocyanidin/240‐mL serving) for 8 weeks resulted in decreased H. pylori infection rate by 20% as compared with other dosages and placebo (P

Objective: Upper gastrointestinal (UGI) cancers, predominantly gastric cancer (GC) and esophageal cancer (EC), are malignant tumor types with high morbidity and mortality rates. Accumulating studies have focused on metabolomic profiling of UGI cancers in recent years. In this systematic review, we have provided a collective summary of previous findings on metabolites and metabolomic profiling associated with GC and EC. Methods: A systematic search of three databases (Embase, PubMed, and Web of Science) for molecular epidemiologic studies on the metabolomic profiles of GC and EC was conducted. The Newcastle–Ottawa Scale (NOS) was used to assess the quality of the included articles. Results: A total of 52 original studies were included for review. A number of metabolites were differentially distributed between GC and EC cases and non-cases, including those involved in glycolysis, anaerobic respiration, tricarboxylic acid cycle, and protein and lipid metabolism. Lactic acid, glucose, citrate, and fumaric acid were among the most frequently reported metabolites of cellular respiration while glutamine, glutamate, and valine were among the most commonly reported amino acids. The lipid metabolites identified previously included saturated and unsaturated free fatty acids, aldehydes, and ketones. However, the key findings across studies to date have been inconsistent, potentially due to limited sample sizes and the majority being hospital-based case-control analyses lacking an independent replication group. Conclusions: Studies on metabolomics have thus far provided insights into etiological factors and biomarkers for UGI cancers, supporting the potential of applying metabolomic profiling in cancer prevention and management efforts.

Background The effectiveness of endoscopic screening on gastric cancer has not been widely investigated in China and the screening interval of repeated screening has not been determined. Methods In a population-based prospective study, we included 375,800 individuals, 14,670 of whom underwent endoscopic screening (2012–2018). We assessed the associations between endoscopic screening and risk of incident gastric cancer and gastric cancer-specific mortality, and examined changes in overall survival and disease-specific survival following screening. The optimal screening interval for repeated endoscopy for early detection of gastric cancer was explored. Results Ever receiving endoscopic screening significantly decreased the risk of invasive gastric cancer (age- and sex-adjusted relative risk [RR] 0.69, 95 % confidence interval [CI] 0.52–0.92) and gastric cancer-specific mortality (RR 0.33, 95 %CI 0.20–0.56), particularly for noncardia gastric cancer. Repeated screening strengthened the beneficial effect on invasive gastric cancer-specific mortality of one-time screening. Among invasive gastric cancers, screening-detected individuals had significantly better overall survival (RR 0.18, 95 %CI 0.13–0.25) and disease-specific survival (RR 0.18, 95 %CI 0.13–0.25) than unscreened individuals, particularly for those receiving repeated endoscopy. For individuals with intestinal metaplasia or low grade intraepithelial neoplasia, repeated endoscopy at an interval of Conclusion Endoscopic screening prevented gastric cancer occurrence and death, and improved its prognosis in a population-based study. Repeated endoscopy enhanced the effectiveness. Screening interval should be based on gastric lesion severity.

Background Molecular features underlining the multistage progression of gastric lesions and development of early gastric cancer (GC) are poorly understood, restricting the ability to GC prevention and management. Methods We portrayed proteomic landscape and explored proteomic signatures associated with progression of gastric lesions and risk of early GC. Tissue proteomic profiling was conducted for a total of 324 subjects. A case-control study was performed in the discovery stage (n=169) based on populations from Linqu, a known high-risk area for GC in China. We then conducted two-stage validation, including a cohort study from Linqu (n = 56), with prospective follow-up for progression of gastric lesions (280-473 days), and an independent case-control study from Beijing (n = 99). Findings There was a clear distinction in proteomic features for precancerous gastric lesions and GC. We derived four molecular subtypes of gastric lesions and identified subtype-S4 with the highest progression risk. We found 104 positively-associated and 113 inversely-associated proteins for early GC, with APOA1BP, PGC, HPX and DDT associated with the risk of gastric lesion progression. Integrating these proteomic signatures, the ability to predict progression of gastric lesions was significantly strengthened (areas-under-the-curve=0.88 (95%CI: 0.78-0.99) vs. 0.56 (0.36-0.76), Delong's P = 0.002). Immunohistochemistry assays and examination at mRNA level validated the findings for four proteins. Interpretation We defined proteomic signatures for progression of gastric lesions and risk of early GC, which may have translational significance for identifying particularly high-risk population and detecting GC at an early stage, improving potential for targeted GC prevention. Funding The funders are listed in the Acknowledgement.

ObjectiveGastrointestinal microbiota may be involved in Helicobacter pylori-associated gastric cancer development. The aim of this study was to explore the possible microbial mechanisms in gastric carcinogenesis and potential dysbiosis arising from H. pylori infection.DesignDeep sequencing of the microbial 16S ribosomal RNA gene was used to investigate alterations in paired gastric biopsies and stool samples in 58 subjects with successful and 57 subjects with failed anti-H. pylori treatment, relative to 49 H. pylori negative subjects.ResultsIn H. pylori positive subjects, richness and Shannon indexes increased significantly (both pH. pylori positive mucosa was associated with advanced gastric lesions (chronic atrophic gastritis and intestinal metaplasia/dysplasia) and could be reversed by eradication. Strong coexcluding interactions between Helicobacter and Fusobacterium, Neisseria, Prevotella, Veillonella, Rothia were found only in advanced gastric lesion patients, and were absent in normal/superficial gastritis group. Changes in faecal microbiota included increased Bifidobacterium after successful H. pylori eradication and more upregulated drug-resistant functional orthologs after failed treatment.ConclusionH. pylori infection contributes significantly to gastric microbial dysbiosis that may be involved in carcinogenesis. Successful H. pylori eradication potentially restores gastric microbiota to a similar status as found in uninfected individuals, and shows beneficial effects on gut microbiota.

Gastric cancer (GC) is the fifth most common cancer and the third leading cause of cancer death worldwide (1). It is imperative to identify patients with GC at a high risk for poor prognosis, so that timely and appropriate treatment strategy can be applied. Although a considerable proportion of patients are diagnosed at an advanced stage, patient outcomes can vary significantly even for patients with similar clinical features. The host heterogeneity in somatic or germline changes may have led to different prognosis. Several studies have examined both genetic and epigenetic alterations as potential prognostic factors for GC. Alternative patterns of messenger RNA (mRNA) expression involved in cycle regulation (2), cell adhesion (3), angiogenesis (4), and tumor carcinogenesis (5) have been reported to play an important role in forecasting survival outcome of GC. One study examined the gene expression profile of 65 patients with GC based on DNA microarray data and reported 6 mRNAs associated with GC prognosis (6). Another study reported 3 mRNAs associated with GC survival based on DNA microarray data of 21 patients with GC (7). A recent study reported 25 mRNAs associated with GC prognosis using DNA microarray data of 78 patients with GC (8). These studies were limited by either small sample size or lacking suitable validation datasets, restricting the possible application of the reported mRNAs associated with GC prognosis in clinical practices. Therefore, it is imperative to identify novel mRNA signatures robustly associated with GC survival. The booming development in high-throughput transcriptome sequencing and microarray technologies have provided opportunities to establish mRNA signatures associated with GC survival. In the present study, we took advantage of the publicly available databases to establish novel mRNA signatures, which may predict GC prognosis. Discovery of potential mRNAs was conducted among 441 patients with GC based on the Cancer Genome Atlas (TCGA), with information on clinical characteristics and vital status. Gene ontology functional enrichment analysis and pathway enrichment analysis were conducted to interrogate the possible biological functions. The independent external microarray data from the Gene Expression Omnibus (GEO) was used to validate these candidate mRNAs. A risk score model was then constructed using the validated mRNAs to testify the potential predictive value of integrated mRNA signature for GC prognosis.

Gastric cancer (GC) is one of the major cancers in China and all over the world. Most GCs are diagnosed at an advanced stage with unfavorable prognosis. Along with some other countries, China has developed the government-funded national screening programs for GC and other major cancers. GC screening has been shown to effectively decrease the incidence of and mortality from GC in countries adopting nationwide screening programs (Japan and Korea) and in studies based on selected Chinese populations. The screening of GC relies mostly on gastroendoscopy, the accuracy, reliability and safety of which have been indicated by previous studies. However, considering its invasive screening approach, requirements on skilled endoscopists and pathologists, and a high cost, developing noninvasive methods to amend endoscopic screening would be highly needed. Numerous studies have examined biomarkers for GC screening and the combination of biomarkers involving pepsinogen, gastrin, and Helicobacter pylori antibodies has been proposed for risk stratification, seeking to narrow down the high-risk populations for further endoscopy. Despite all the achievements of endoscopic screening, evidence on appropriate screening age, intervals for repeated screening, novel biomarkers promoting precision prevention, and health economics need to be accumulated to inform policymakers on endoscopic screening in China. With the guide of Health China 2030 Planning Outline, we have golden opportunities to promote prevention and control of GC. In this review, we summarize the characteristics of screening programs in China and other East Asian countries and introduce the past and current approaches and strategies for GC screening, aiming for featuring the latest advances and key challenges, and illustrating future visions of GC screening.

Background Few studies have examined prognostic outcomes-associated molecular signatures other than overall survival (OS) for gastric cancer (GC). We aimed to identify DNA methylation biomarkers associated with multiple prognostic outcomes of GC in an epigenome-wide association study. Methods Based on the Cancer Genome Atlas (TCGA), DNA methylation loci associated with OS (n = 381), disease-specific survival (DSS, n = 372), and progression-free interval (PFI, n = 383) were discovered in training set subjects (false discovery rates P-values n = 247). Gene set enrichment analyses were conducted to explore the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways simultaneously enriched for multiple GC prognostic outcomes. Methylation correlated blocks (MCBs) were identified for co-methylation patterns associated with GC prognosis. Based on key CpGs, risk score models were established to predict four prognostic outcomes. Spearman correlation analyses were performed between key CpG sites and their host gene mRNA expression. Results We newly identified DNA methylation of seven CpGs significantly associated with OS, DSS, and PFI of GC, including cg10399824 (GRK5), cg05275153 (RGS12), cg24406668 (MMP9), cg14719951(DSC3), and cg25117092 (MED12L), and two in intergenic regions (cg11348188 and cg11671115). Except cg10399824 and cg24406668, five of them were also significantly associated with DFI of GC. Neuroactive ligand-receptor interaction pathway was suggested to play a key role in the effect of DNA methylation on GC prognosis. Consistent with individual CpG-level association, three MCBs involving cg11671115, cg14719951, and cg24406668 were significantly associated with multiple prognostic outcomes of GC. Integrating key CpG loci, two risk score models performed well in predicting GC prognosis. Gene body DNA methylation of cg14719951, cg10399824, and cg25117092 was associated with their host gene expression, whereas no significant associations between their host gene expression and four clinical prognostic outcomes of GC were observed. Conclusions We newly identified seven CpGs associated with OS, DSS, and PFI of GC, with five of them also associated with DFI, which might inform patient stratification in clinical practices.

Additional file 1: Supplementary Table S1. Detailed information on gene set enrichment analyses for gene body DNA methylation in relation to four clinical endpoints of GC patients in TCGA.

In addition to Helicobacter pylori (H.pylori), gastric microbiota may be involved in carcinogenesis process. However, the longitudinal study to assess changes in the gastric microbiota associated with the development of gastric carcinogenesis is still limited. The aim of this study is to explore dynamic microbial alterations in gastric cancer (GC) development based on a 4-year endoscopic follow-up cohort in Linqu County, China. Microbial alterations were investigated by deep sequencing of the microbial 16S ribosomal RNA gene in 179 subjects with various gastric lesions, and validated in paired gastric biopsies prospectively collected before and after lesion progression and in non-progression controls. Significant differences were found in microbial diversity and community structure across various gastric lesions, with 62 candidate differential taxa between at least two lesion groups. Further validations identified Helicobacter, Bacillus, Capnocytophaga and Prevotella to be associated with lesion progression-to-dysplasia (DYS)/GC (all P < 0.05), especially for subjects progressing from intestinal metaplasia (IM) to DYS/GC. The combination of the four genera in a microbial dysbiosis index showed a significant difference after lesion progression-to-DYS/GC compared to controls (P = 0.027). The panel including the four genera identified subjects after progression-to-DYS/GC with an area under the receiver-operating curve (AUC) of 0.941. Predictive significance was found before lesion progression-to-DYS/GC with an AUC = 0.776 and an even better AUC (0.927) for subjects progressing from IM to DYS/GC. Microbiota may play different roles at different stages in gastric carcinogenesis. A panel of bacterial genera associated with gastric lesions may help to assess gastric microbial dysbiosis and show potential predictive values for lesion progression. Our findings provide new clues for the microbial mechanism of H.pylori-associated carcinogenesis.

Objective To identify serum biomarkers that may predict the short or long term outcomes of anti-Helicobacter pylori (H. pylori) treatment, a follow-up study was performed based on an intervention trial in Linqu County, China. Methods A total of 529 subjects were selected randomly from 1,803 participants to evaluate total anti-H. pylori immunoglobulin G (IgG) and 10 specific antibody levels before and after treatment at 1-, 2- and 7.3-year. The outcomes of anti-H. pylori treatment were also parallelly assessed by13C-urea breath test at 45-d after treatment and 7.3-year at the end of follow-up. Results We found the medians of anti-H. pylori IgG titers were consistently below cut-off value through 7.3 years in eradicated group, however, the medians declined in recurrence group to 1.2 at 1-year after treatment and slightly increased to 2.0 at 7.3-year. While the medians were significantly higher (>3.0 at 2- and 7.3-year) among subjects who failed the eradication or received placebo. For specific antibody responses, baseline seropositivities of FliD and HpaA were reversely associated with eradication failure [for FliD, odds ratio (OR)=0.44, 95% confidence interval (95% CI): 0.27-0.73; for HpaA, OR=0.32, 95% CI: 0.17-0.60]. The subjects with multiple positive specific antibodies at baseline were more likely to be successfully eradicated in a linear fashion (Ptrend=0.006). Conclusions Our study suggested that total anti-H. pylori IgG level may serve as a potential monitor of long-term impact on anti-H. pylori treatment, and priority forH. pylori treatment may be endowed to the subjects with multiple seropositive antibodies at baseline, especially for FliD and HapA.

Background: Telomeres have long been found to be involved in cancer development, while little was known about the dynamic changes of telomere length in carcinogenesis process.Methods: The present study longitudinally investigated telomere alterations of cell-free DNA (cfDNA) in 86 gastric cancer (GC) subjects recruited through a 16-year prospective cohort with 2–4 serums collected before each GC-diagnosis from baseline and three follow-up time-points (a total of 276 samples). As the control, 86 individual-matched cancer-free subjects were enrolled with 276 serums from the matched calendar year.Results: In the 73 pairs of baseline serums from GC and control subjects, shortened telomeres showed increased subsequent GC risk [odds ratio (OR) = 9.17, 95% CI: 2.72–31.25 for 1 unit shortening]. In each baseline gastric lesion category, higher risks of GC progression were also found with shortened cfDNA telomeres; ORs per 1 unit shortening were 6.99 (95% CI: 1.63–30.30) for mild gastric lesions, 6.06 (95% CI: 1.89–19.61) for intestinal metaplasia and 15.63 (95% CI: 1.91–125.00) for dysplasia. With all measurements from baseline and follow-up time-points, shortened telomeres also showed significant association with GC risk (OR = 7.37, 95% CI: 2.06–26.32 for 1 unit shortening). In temporal trend analysis, shortened telomeres were found in GC subjects compared to corresponding controls more than 3 years ahead of GC-diagnosis (most P < 0.05), while no significant difference was found between two groups within 3 years approaching to GC-diagnosis.Conclusion: Our findings suggest that telomere shortening may be associated with gastric carcinogenesis, which supports further etiological study and potential biomarker for risk stratification.

Objective To assess the effects of Helicobacter pylori treatment, vitamin supplementation, and garlic supplementation in the prevention of gastric cancer. Design Blinded randomized placebo controlled trial. Setting Linqu County, Shandong province, China. Participants 3365 residents of a high risk region for gastric cancer. 2258 participants seropositive for antibodies to H pylori were randomly assigned to H pylori treatment, vitamin supplementation, garlic supplementation, or their placebos in a 2×2×2 factorial design, and 1107 H pylori seronegative participants were randomly assigned to vitamin supplementation, garlic supplementation, or their placebos in a 2×2 factorial design. Interventions H pylori treatment with amoxicillin and omeprazole for two weeks; vitamin (C, E, and selenium) and garlic (extract and oil) supplementation for 7.3 years (1995-2003). Main outcome measures Primary outcomes were cumulative incidence of gastric cancer identified through scheduled gastroscopies and active clinical follow-up through 2017, and deaths due to gastric cancer ascertained from death certificates and hospital records. Secondary outcomes were associations with other cause specific deaths, including cancers or cardiovascular disease. Results 151 incident cases of gastric cancer and 94 deaths from gastric cancer were identified during 1995-2017. A protective effect of H pylori treatment on gastric cancer incidence persisted 22 years post-intervention (odds ratio 0.48, 95% confidence interval 0.32 to 0.71). Incidence decreased significantly with vitamin supplementation but not with garlic supplementation (0.64, 0.46 to 0.91 and 0.81, 0.57 to 1.13, respectively). All three interventions showed significant reductions in gastric cancer mortality: fully adjusted hazard ratio for H pylori treatment was 0.62 (95% confidence interval 0.39 to 0.99), for vitamin supplementation was 0.48 (0.31 to 0.75), and for garlic supplementation was 0.66 (0.43 to 1.00). Effects of H pylori treatment on both gastric cancer incidence and mortality and of vitamin supplementation on gastric cancer mortality appeared early, but the effects of vitamin supplementation on gastric cancer incidence and of garlic supplementation only appeared later. No statistically significant associations were found between interventions and other cancers or cardiovascular disease. Conclusions H pylori treatment for two weeks and vitamin or garlic supplementation for seven years were associated with a statistically significant reduced risk of death due to gastric cancer for more than 22 years. H pylori treatment and vitamin supplementation were also associated with a statistically significantly reduced incidence of gastric cancer. Trial registration ClinicalTrials.gov NCT00339768.

Importance Metabolic deregulation plays an important role in gastric cancer (GC) development. To date, no studies have comprehensively explored the metabolomic profiles along the cascade of gastric lesions toward GC. Objective To draw a metabolic landscape and define metabolomic signatures associated with the progression of gastric lesions and risk of early GC. Design, setting, and participants A 2-stage, population-based cohort study was initiated in 2017 in Linqu County, Shandong Province, China, a high-risk area for GC. Prospective follow-up was conducted during the validation stage (June 20, 2017, to May 27, 2020). A total of 400 individuals were included based on the National Upper Gastrointestinal Cancer Early Detection Program in China. The discovery stage involved 200 individuals with different gastric lesions or GC (high-grade intraepithelial neoplasia or invasive GC). The validation stage prospectively enrolled 152 individuals with gastric lesions who were followed up for 118 to 1063 days and 48 individuals with GC. Exposures Metabolomic profiles and metabolite signatures were examined based on untargeted plasma metabolomics assay. Main outcomes and measures The risk of GC overall and early GC (high-grade intraepithelial neoplasia), and progression of gastric lesions. Results Of the 400 participants, 124 of 200 (62.0%) in the discovery set were men; mean (SD) age was 56.8 (7.5) years. In the validation set, 136 of 200 (68.0%) were men; mean (SD) age was 57.5 (8.1) years. Distinct metabolomic profiles were noted for gastric lesions and GC. Six metabolites, including α-linolenic acid, linoleic acid, palmitic acid, arachidonic acid, sn-1 lysophosphatidylcholine (LysoPC)(18:3), and sn-2 LysoPC(20:3) were significantly inversely associated with risk of GC overall and early GC (high-grade intraepithelial neoplasia). Among these metabolites, the first 3 were significantly inversely associated with gastric lesion progression, especially for the progression of intestinal metaplasia (α-linolenic acid: OR, 0.42; 95% CI, 0.18-0.98; linoleic acid: OR, 0.43; 95% CI, 0.19-1.00; and palmitic acid: OR, 0.32; 95% CI, 0.13-0.78). Compared with models including only age, sex, Helicobacter pylori infection, and gastric histopathologic findings, integrating these metabolites significantly improved the performance for predicting the progression of gastric lesions (area under the curve [AUC], 0.86; 95% CI, 0.70-1.00 vs AUC, 0.69; 95% CI, 0.50-0.88; P = .02) and risk of early GC (AUC, 0.83; 95% CI, 0.58-1.00 vs AUC, 0.61; 95% CI, 0.31-0.91; P = .03). Conclusions and relevance This study defined metabolite signatures that might serve as meaningful biomarkers for assessing high-risk populations and early diagnosis of GC, possibly advancing targeted GC prevention and control.

Subaqueous volcanic-hydrothermal field is a complex hybrid geological system, where sediments originated from volcanic, hydrothermal, lacustrine, terrestrial, and biotic sources are mixed. Recent petrological studies on such sediments have indicated a potential relationship between volcanic-hydrothermal activities and oil generation and accumulation. Here, we explore the mechanisms of sedimentation and oil accumulation in well-laminated organic-rich fine-grained sedimentary rocks in Permian Lucaogou Formation deposited in the lacustrine Santanghu rift basin, NW China. We conducted petrographic, carbon and oxygen isotopic, and organic geochemical analyses of fifty-four core samples from three wells (forty-eight samples from Well W1, two from W2, four from W3) designed for tight oil exploration. Four main observations and interpretations are: 1) The fine-grained sediments are a mixture of volcanic-hydrothermal detrital feldspar grains, authigenic quartz crystals, and primary lacustrine dolomite, forming interbedded tuffaceous shale and dolostone; 2) authigenic quartz crystals were precipitated from acidic hydrothermal fluids, whereas fine-grained angular alkaline feldspars were derived from subaqueous volcanic eruption; 3) the TOC content and oil generation potential increase with increased mixing of feldspars and carbonate minerals. Hence, the dolomite-bearing tuffaceous shale and tuffaceous dolostone are the best source rocks; and 4) the fine-grained sedimentary rocks are interpreted as a subaqueous volcanic-hydrothermal deposit that controls the source potential. The sedimentary processes of an ancient sediment-hosted geothermal system and its implications on hydrocarbon source rocks and accumulation were first identified. Algal bloom induced by subaqueous eruptions is the main cause for episodic deposition of organic matter and extreme heterogeneity in both lithofacies and source-rock distribution. The results suggest that cone-shaped buildups on seismic sections, which were formed by volcanic-hydrothermal deposits and contain highly-mixed feldspar and carbonate sediments, are the best hydrocarbon reservoirs, and demonstrate a strong relationship between volcanic-hydrothermal activities and hydrocarbon accumulation in an extensional tectonic setting.

Nonclustered protocadherins (PCDH) family is a group of cell–cell adhesion molecules. We have found differentially methylated genes in the nonclustered PCDHs family associated with Helicobacter pylori (H. pylori) infection in prior genome-wide methylation analysis. To further investigate the methylation and expression of nonclustered PCDHs encoding genes in H. pylori--related gastric carcinogenesis process, four candidate genes including PCDH7, PCDH10, PCDH17, and PCDH20 were selected, which were reported to be tumor suppressors for digestive cancers. A total of 747 participants with a spectrum of gastric lesions were enrolled from a high-risk population of gastric cancer. Promoter methylation levels of four genes were significantly higher in H. pylori–positive subjects than the negative group (all P < 0.001). Elevated methylation levels of PCDH10 and PCDH17 were observed with the increasing severity of gastric lesions (both Ptrend < 0.001). In the protein expression analysis, PCDH17 expression was inversely associated with gastric lesions; the OR [95% confidence interval (CI)] was 0.49 (0.26–0.95) for chronic atrophic gastritis (CAG), 0.31 (0.15–0.63) for intestinal metaplasia, and 0.38 (0.19–0.75) for indefinite dysplasia and dysplasia, compared with superficial gastritis. In addition, PCDH10 expression was significantly lower in CAG (OR, 0.40; 95% CI, 0.24–0.68). The inverse association between methylation and protein expression of PCDH10 and PCDH17 was further supported when we explored the methylation and mRNA expression in The Cancer Genome Atlas database (all P < 0.001). Our study found elevated promoter methylation and decreased expression of PCDH10 and PCDH17 in advanced gastric lesions, suggesting that elevated PCDH10 and PCDH17 methylation may be an early event in gastric carcinogenesis. Cancer Prev Res; 11(11); 717–26. ©2018 AACR.

Helicobacter pylori (H. pylori) infection and cytokine-mediated inflammatory responses play important roles in gastric cancer (GC) pathogenesis. To investigate an association between genetic polymorphisms in interleukin (IL)-1β, IL-4R, IL-8, IL-10, IL-16, IL-18RAP, IL-22, and IL-32 and risks of GC and its precursors, a population-based study was conducted in Linqu County. Genotypes were determined by Sequenom MassARRAY platform in 132 GC cases and 1198 subjects with gastric lesions. The H. pylori status was determined by (13)C-urea breath test ((13)C-UBT) or enzyme-linked immunosorbent assay (ELISA). Among 11 candidate single nucleotide polymorphisms (SNPs), subjects carrying IL-18RAP rs917997 AA genotype were associated with risk of GC [adjusted odds ratio (OR) = 1.83, 95 % confidence interval (CI) 1.14-2.92] or chronic atrophic gastritis (CAG; OR = 1.55, 95 % CI 1.07-2.24). The risk of GC was also increased in subjects carrying IL-32 rs2015620 A allele (AA + AT; OR = 1.92, 95 % CI 1.09-3.39). Moreover, elevated risks of CAG (OR = 2.64, 95 % CI 1.89-3.69), intestinal metaplasia (IM; OR = 5.58, 95 % CI 3.86-8.05), and dysplasia (DYS; OR = 1.64, 95 % CI 1.18-2.26) were observed in subjects with IL-22 rs1179251 CC genotype. Stratified analysis indicated that risks of GC and its precursors were elevated in subjects with IL-32 rs2015620 A allele (AA + AT) or IL-22 rs1179251 CC genotype and H. pylori infection, and significant interactions between these two SNPs and H. pylori infection were found. These findings suggested that IL-18RAP rs917997, IL-32 rs2015620, IL-22 rs1179251, and interactions between these polymorphisms and H. pylori infection were associated with risks of gastric lesions. Genetic polymorphisms of interleukins may play crucial roles in H. pylori-induced gastric carcinogenesis.

The performance of diagnostic tests in intervention trials of Helicobacter pylori (H.pylori) eradication is crucial, since even minor inaccuracies can have major impact. To determine the cut-off point for 13C-urea breath test (13C-UBT) and to assess if it can be further optimized by serologic testing, mathematic modeling, histopathology and serologic validation were applied. A finite mixture model (FMM) was developed in 21,857 subjects, and an independent validation by modified Giemsa staining was conducted in 300 selected subjects. H.pylori status was determined using recomLine H.pylori assay in 2,113 subjects with a borderline 13C-UBT results. The delta over baseline-value (DOB) of 3.8 was an optimal cut-off point by a FMM in modelling dataset, which was further validated as the most appropriate cut-off point by Giemsa staining (sensitivity = 94.53%, specificity = 92.93%). In the borderline population, 1,468 subjects were determined as H.pylori positive by recomLine (69.5%). A significant correlation between the number of positive H.pylori serum responses and DOB value was found (rs = 0.217, P 13C-UBT in community-based studies, and a second method to determine H.pylori status for subjects with borderline value of 13C-UBT was necessary and recommended.

Objective To assess the effects of Helicobacter pylori treatment, vitamin supplementation, and garlic supplementation in the prevention of gastric cancer. Design Blinded randomized placebo controlled trial. Setting Linqu County, Shandong province, China. Participants 3365 residents of a high risk region for gastric cancer. 2258 participants seropositive for antibodies to H pylori were randomly assigned to H pylori treatment, vitamin supplementation, garlic supplementation, or their placebos in a 2×2×2 factorial design, and 1107 H pylori seronegative participants were randomly assigned to vitamin supplementation, garlic supplementation, or their placebos in a 2×2 factorial design. Interventions H pylori treatment with amoxicillin and omeprazole for two weeks; vitamin (C, E, and selenium) and garlic (extract and oil) supplementation for 7.3 years (1995-2003). Main outcome measures Primary outcomes were cumulative incidence of gastric cancer identified through scheduled gastroscopies and active clinical follow-up through 2017, and deaths due to gastric cancer ascertained from death certificates and hospital records. Secondary outcomes were associations with other cause specific deaths, including cancers or cardiovascular disease. Results 151 incident cases of gastric cancer and 94 deaths from gastric cancer were identified during 1995-2017. A protective effect of H pylori treatment on gastric cancer incidence persisted 22 years post-intervention (odds ratio 0.48, 95% confidence interval 0.32 to 0.71). Incidence decreased significantly with vitamin supplementation but not with garlic supplementation (0.64, 0.46 to 0.91 and 0.81, 0.57 to 1.13, respectively). All three interventions showed significant reductions in gastric cancer mortality: fully adjusted hazard ratio for H pylori treatment was 0.62 (95% confidence interval 0.39 to 0.99), for vitamin supplementation was 0.48 (0.31 to 0.75), and for garlic supplementation was 0.66 (0.43 to 1.00). Effects of H pylori treatment on both gastric cancer incidence and mortality and of vitamin supplementation on gastric cancer mortality appeared early, but the effects of vitamin supplementation on gastric cancer incidence and of garlic supplementation only appeared later. No statistically significant associations were found between interventions and other cancers or cardiovascular disease. Conclusions H pylori treatment for two weeks and vitamin or garlic supplementation for seven years were associated with a statistically significant reduced risk of death due to gastric cancer for more than 22 years. H pylori treatment and vitamin supplementation were also associated with a statistically significantly reduced incidence of gastric cancer. Trial registration ClinicalTrials.gov NCT00339768 .

Gastric cancer (GC) is a consequence of multifactorial and multistep processes. Helicobacter pylori (H. pylori) infection plays a crucial role in gastric carcinogenesis. Long non-coding RNAs (lncRNAs) have shown great potential as powerful cancer biomarkers. To investigate the possible roles of lncRNAs and H. pylori infection in GC development, we measured expression levels of three lncRNAs (H19, LINC00152, uc001lsz) in serum from a total of 285 Chinese participants using reverse transcription-quantitative polymerase chain reaction. We found significant associations between high expression of both H19 and LINC00152 in serum and increased risk of GC; the adjusted OR for H19 was 2.17 (95% CI: 1.21-3.88), and for LINC00152 was 2.09 (95% CI: 1.18-3.70). Further analyses indicated an elevated risk of GC in subjects with both high H19 expression and H. pylori infection (OR: 13.75, 95% CI: 4.75-39.84). Significant joint effect between LINC00152 and H. pylori infection on risk of GC was also found (OR: 17.49, 95% CI: 4.78-63.92). Serum H19 and LINC00152 may serve as potential biomarkers for diagnosis of GC, particularly for those with H. pylori infection.

Background Genetic variants of nucleotide-binding oligomerization domain-containing protein (NOD) may influence the outcome of Helicobacter pylori (H. pylori) infection and gastric carcinogenesis. To explore genetic variants of NOD1 and NOD2 in association with gastric cancer (GC) and its precursors, a population-based study was conducted in Linqu County, China. Methods TagSNPs of NOD1 and NOD2 were genotyped by Sequenom MASS array in 132 GCs, and 1,198 subjects with precancerous gastric lesions, and were correlated with evolution of gastric lesions in 766 subjects with follow-up data. Results Among seven tagSNPs, NOD1 rs2709800 and NOD2 rs718226 were associated with gastric lesions. NOD1 rs2709800 TG genotype carriers had a decreased risk of intestinal metaplasia (IM, OR: 0.53; 95% CI: 0.31–0.92), while NOD2 rs718226 G allele (AG/GG) showed increased risks of dysplasia (DYS, OR: 2.96; 95% CI: 1.86–4.71) and GC (OR: 2.35; 95% CI: 1.24–4.46). Moreover, an additive interaction between rs718226 and H. pylori was found in DYS or GC with synergy index of 3.08 (95% CI: 1.38–6.87) or 3.99 (95% CI: 1.55–10.22), respectively. The follow-up data indicated that NOD2 rs2111235 C allele (OR: 0.52; 95% CI: 0.32–0.83) and rs7205423 G allele (OR: 0.56; 95% CI: 0.35–0.89) were associated with decreased risk of progression in H. pylori-infected subjects. Conclusions NOD1 rs2709800, NOD2 rs718226, rs2111235, rs7205423 and interaction between rs718226 and H. pylori infection may be related to risk of gastric lesions.

Genetic polymorphisms of Toll-like receptor (TLR) 1 and 10 may influence Helicobacter pylori (H. pylori) susceptibility. To evaluate associations between TLR1 and 10 polymorphisms, H. pylori infection, and precancerous gastric lesions, a population-based study was conducted in a high-risk Chinese population. Three single-nucleotide polymorphisms, TLR1 rs4833095, TLR10 rs10004195, and TLR10 rs4129009 were genotyped by TaqMan SNP genotyping assay in 2553 participants with diverse gastric lesions. The status of H. pylori infection was determined by (13)C-urea breath test. TLR1 rs4833095 T and TLR10 rs10004195 T alleles were the minor alleles and showed in linkage disequilibrium (D'=0.98, r(2)=0.73) in the Chinese population. A decreased risk of H. pylori infection was observed in subjects with TLR1 rs4833095 CT genotype [adjusted odds ratio (OR)=0.80; 95% confidence interval (CI): 0.66-0.96] or T allele (OR=0.82; 95%CI: 0.69-0.99). Moreover, subjects carrying TLR1 rs4833095 TT genotype were associated with reduced risks of chronic atrophic gastritis (CAG, OR=0.66; 95%CI: 0.45-0.97) and intestinal metaplasia (IM, OR=0.57; 95%CI: 0.36-0.90). The risk of CAG was also decreased in subjects carrying TLR10 rs10004195 T allele (OR=0.75; 95%CI: 0.57-0.99). Furthermore, haplotype analysis indicated that haplotype TT of rs4833095 and rs10004195 had a protective effect on H. pylori infection (OR=0.83; 95%CI: 0.72-0.96) or precancerous gastric lesions (OR=0.78; 95%CI: 0.64-0.96 for CAG, and OR=0.74; 95%CI: 0.57-0.96 for IM). These findings suggest that TLR1 rs4833095 and TLR10 rs10004195 may play crucial roles in H. pylori susceptibility and gastric pathogenesis.

To determine the distributions of six Helicobacter pylori (Hp)-specific antibodies in a high-risk population of gastric cancer (GC) and explore the relationship between Hp virulence factors and precancerous gastric lesions.Based on the two intervention trials conducted in Linqu County, the seropositivities for CagA, VacA, GroEL, UreA, HcpC and GGT were assessed by recombinant immunoassay (recomLine) in 623 participants with H. pylori infection determined by (13)C-urea breath test ((13)C-UBT) and/or enzyme linked immunosorbent assay (ELISA).In a total of 623 participants were detected by recomLine analysis, of which 594 were Hp-positive. The seropositivities rates of CagA, VacA, GroEL, UreA, HcpC and GGT were 84.0%, 38.2%, 66.7%, 17.7%, 58.8% and 42.8%, respectively. A total of 523 participants were determined as type I infection of Hp, accounting for 88.1%. Compared with superficial gastritis (SG), the infection rate of Hp type I was higher in the chronic atrophic gastritis (CAG) (P = 0.001).The results of this population-based study suggest that the virulence factors of Hp may be related to the development of GC in a Chinese high-risk population. The recomLine analysis may serve as a tool for identification of Hp strains and prediction of high-risk population of GC.

Helicobacter pylori-specific proteins are involved in gastric carcinogenesis. To investigate the seroprevalence of six H. pylori-specific antibodies in patients with different gastric histology, and the impact of seropositivities on the evolution of precancerous gastric lesions, a follow-up study was conducted in Linqu County, China. The seropositivities for CagA, VacA, GroEL, UreA, HcpC and gGT were assessed by recomLine analysis in 573 H. pylori-positive subjects and correlated with evolution of precancerous gastric lesions. We found that the score of H. pylori recomLine test was significantly increased in subjects with chronic atrophic gastritis (CAG, p0.0001) or intestinal metaplasia (IM, p = 0.0125), and CagA was an independent predictor of advanced gastric lesions, adjusted odds ratios (ORs) were 2.54 (95% CI = 1.42-4.55) for IM and 2.38 (95% CI = 1.05-5.37) for dysplasia (DYS). Moreover, seropositivities for CagA and GroEL were identified as independent predictors for progression of gastric lesions in a longitudinal study, and ORs were 2.89 (95% CI = 1.27-6.59) and 2.20 (95% CI = 1.33-3.64), respectively. Furthermore, the risk of progression was more pronounced in subjects with more than three positive antigens (p(for) trend = 0.0003). This population-based study revealed that seropositivities for CagA and GroEL might be potential markers to identify patients infected with high-risk H. pylori strains, which are related to the development of GC in a Chinese high-risk population, and recomLine test might serve as a tool for risk stratification.

A simple and reliable method was developed for the determination of serum copper and zinc in different chemical forms by graphite furnace atomic absorption spectrometry (GFAAS) with ethanol-EDTA precipitation. The serum and ethanol were mixed with volume ratio 1 : 2. The mixture was incubated at 70 degrees C and ultra-centrifuged to precipitate proteins. Zinc and copper can be released from albumin after EDTA treating. Thus, macroglobulin-zinc, ceruloplasmin-copper, and albumin-bound zinc or copper could be determined by two proposed precipitation steps. The determination limit of copper (3sigma) was 1.2 microg x L(-1) and the recovery was 92.3%-104%, while the determination limit of zinc (3sigma) was 0.098 microg x L(-1), and the recovery was 90%-107%. This two-step precipitation method can be used to determine serum zinc and copper in various chemical forms in tumor, Wilson patients and heathy human.