Helicobacter pylori and gastric cancer

Helicobacter pylori upregulates circPGD and promotes development of gastric cancer

PURPOSE

Helicobacter pylori (H. pylori) has unique biochemical traits and pathogenic mechanisms, which make it a substantial cause of gastrointestinal cancers. Circular RNAs (circRNAs) have concurrently been identified as an important participating factor in the pathophysiology of several different cancers. However, the underlying processes and putative interactions between H. pylori and circRNAs have received very little attention. To address this issue, we explored the interaction between H. pylori and circRNAs to investigate how they might jointly contribute to the occurrence and development of gastric cancer.

METHODS

Changes in circPGD expression in H. pylori were detected using qRT-PCR. Cell proliferation and migration changes were assayed by colony formation, the CCK-8 assay and the transwell assay. Apoptosis was measured by flow cytometry. Western blot was conducted to detect changes in cell migration, apoptosis, proliferation and inflammation-associated proteins. QRT-PCR was used to measure changes in circPGD and inflammation-associated factors.

RESULTS

We found that H. pylori induced increased circPGD expression in infected human cells and facilitated gastric cancer progression in three ways by promoting cell proliferation and migration, enhancing the inflammatory response, and inhibiting apoptosis.

CONCLUSIONS

CircPGD appears to play a role in H. pylori-related gastric cancer and may thus be a viable, novel target for therapeutic intervention.

The role of metal ions in the occurrence, progression, drug resistance, and biological characteristics of gastric cancer

Metal ions exert pivotal functions within the human body, encompassing essential roles in upholding cell structure, gene expression regulation, and catalytic enzyme activity. Additionally, they significantly influence various pathways implicated in divergent mechanisms of cell death. Among the prevailing malignant tumors of the digestive tract worldwide, gastric cancer stands prominent, exhibiting persistent high mortality rates. A compelling body of evidence reveals conspicuous ion irregularities in tumor tissues, encompassing gastric cancer. Notably, metal ions have been observed to elicit distinct contributions to the progression, drug resistance, and biological attributes of gastric cancer. This review consolidates pertinent literature on the involvement of metal ions in the etiology and advancement of gastric cancer. Particular attention is directed towards metal ions, namely, Na, K, Mg, Ca, Fe, Cu, Zn, and Mn, elucidating their roles in the initiation and progression of gastric cancer, cellular demise processes, drug resistance phenomena, and therapeutic approaches.

Association of meat consumption with the risk of gastrointestinal cancers: a systematic review and meta-analysis

BACKGROUND

The association between gastrointestinal cancer and types of meat consumption, including red meat, processed meat, or a combination of both, remains disputable. Therefore, we performed a systematic review and meta-analysis of prospective cohort studies to estimate the association between meat consumption and gastrointestinal cancer risk.

METHODS

PubMed, EmBase, and the Cochrane library databases were searched systematically for eligible studies that investigated the relation between meat consumption and the risk of developing gastrointestinal cancers, including esophageal cancer (EC), gastric cancer (GC), colorectal cancer (CRC), colon cancer (CC), rectal cancer (RC), pancreatic cancer (PC), and hepatocellular carcinoma (HCC) throughout February, 2023. The pooled relative risk (RR) with 95% confidence interval (CI) was assigned as an effect estimate and calculated using a random-effects model with inverse variance weighting.

RESULTS

Forty cohorts comprising 3,780,590 individuals were selected for the final quantitative analysis. The summary results indicated that a higher red meat consumption was associated with an increased risk of CRC (RR: 1.09; 95% CI: 1.02-1.16; P = 0.007) and CC (RR: 1.13; 95% CI: 1.03-1.25; P = 0.011). Moreover, a higher processed meat consumption was associated with an increased risk of CRC (RR: 1.19; 95% CI: 1.13-1.26; P < 0.001), CC (RR: 1.24; 95% CI: 1.13-1.26; P < 0.001), and RC (RR: 1.24; 95% CI: 1.08-1.42; P = 0.002). Furthermore, a higher total consumption of red and processed meat was associated with an increased risk of CRC (RR: 1.13; 95% CI: 1.06-1.20; P < 0.001), CC (RR: 1.17; 95% CI: 1.04-1.33; P = 0.012), and RC (RR: 1.20; 95% CI: 1.04-1.39; P = 0.016). Finally, the strength of higher consumption of total red and processed meat with the risk of GC, and higher consumption of red meat with the risk of RC in subgroup of high adjusted level was lower than subgroup of moderate adjusted level, while the strength of higher consumption of processed meat with the risk of RC and HCC in subgroup of follow-up ≥ 10.0 years was higher than subgroup of follow-up < 10.0 years.

CONCLUSIONS

This study found that meat consumption was associated with an increased risk of CRC, CC, and RC, and dietary intervention could be considered an effective strategy in preventing CRC.

Meat and dairy products intake is associated with gastric cancer: Case-control study findings

Countries experiencing a significant shift toward Western lifestyle are facing an increased risk of gastric cancer (GC). While many studies have explored the link between diet and GC, the role of meat and dairy consumption remains uncertain. To delve deeper into this association, we conducted a case-control study in Jordan involving 173 GC cases and 314 controls, matched by age and marital status. Using a validated food frequency questionnaire, we assessed the intake of different dairy and meat products. The adjusted odds ratios and corresponding 95% confidence intervals indicated a strong correlation between high intake of red meat, milk, and buttermilk and GC. Our multinomial logistic regression analysis revealed that daily consumption of red meat (≥1 serving/day; OR, 3.34 [95% CI 1.85-6.03, p value of trend <.001], ≥1 serving/day) and weekly intake of milk (2-3 servings/week; OR, 2.04 [95% CI 1.14-3.64, p value of trend = .041]) and buttermilk (2-3 servings/week; OR, 2.07 [95% CI 1.12-3.83, p value of trend = .018], per 2-3 servings/week) were significantly associated with an increased risk of GC. Furthermore, consuming cooked eggs daily (OR = 2.44, 95% CI 1.24-4.79, p trend <.001) or weekly (OR, 3.34, 95% CI 1.58-7.10, p value of trend <.001) was also associated with an increased risk of GC. These findings highlight the potential health risks associated with excessive meat and some dairy products consumption and suggest that a balanced intake of these products, along with eggs, may help prevent GC.

Role of Helicobacter pylori in Gastric Carcinoma: A Review

Gastric cancer (GC) is one of the leading causes of cancer-related deaths globally. Gastritis caused by Helicobacter pylori (H. pylori) is a potent cause of gastrointestinal malignancies. The majority of all humans on the planet have H. pylori invasion in their stomachs, yet only a few diseased people develop GC. The human gastrointestinal system contains a broad population of microorganisms in addition to H. pylori. H. pylori heterogeneity has been studied because not all H. pylori diseases result in cancer. Individuals in the adult age group account for the bulk of gastric carcinoma cases. H. pylori has various strains, which is beneficial for its survival in host cell epithelium for a longer duration of time. Along with H. pylori, oral microbes have a major role in the pathogenicity of gastric carcinoma. The complex ecology of oral microbiota helps to defend against infections, preserve homeostasis, and regulate the immune system. In contrast, oral microbiota is involved in various mechanisms like anti-apoptotic activity, suppression of the immune system of the host, and initiation of chronic inflammation. These oral microbes are also responsible for the development of mutations. Interactions between the host immune system and bacteria promote the progression of cancer. For this review, various research articles were studied, and information was collected using databases like PubMed and Google Scholar. This review emphasizes on the role of H. pylori in gastric carcinoma, its pathogenesis, the role of various virulence factors and risk factors related to it, the role of oral microbiota in gastric carcinoma pathogenesis, diagnostic modalities, treatment options, and preventive measures for gastric carcinoma.

Event dependent overall survival in the population-based LIFE-Adult-Study

BACKROUND

Information about the direct comparability of big data of epidemiological cohort studies and the general population still is lacking, especially regarding all-cause mortality rates. The aim of this study was to investigate the overall survival and the influence of several diagnoses in the medical history on survival time, adjusted to common risk factors in a populations-based cohort.

METHODS

From 10,000 subjects of the population-based cohort LIFE-Adult-Study (Leipzig Research Centre for Civilization Diseases), the medical history and typical risk factors such as age, smoking status and body-mass-index (BMI) were assessed. The survival status was identified from the saxonian population register. Univariate and multivariate analyses were used to determine the influence of the medical history and risk factors on overall survival. To develope an optimal model, the method by Collet [1] was used.

RESULTS

The mortality rate of the participants is approximately half the mortality rate expected for the german population. The selection bias in epidemiological studies needs to be considered whenever interpreting results of epidemiological cohort studies. Nevertheless we have shown that several diagnoses proved to have a negative influence on overall survival time even in this relatively healthy cohort. This study showed the significantly increased mortality risk if the following diseases are reported in medical history of the participants in a large population-based cohort study including adults aged 18 and over: diabetes mellitus (HR 1.533, p = 0.002), hypertension (HR 1.447, p = 0.005), liver cirrhosis (HR 4.251, p < 0.001), osteoporosis (HR 2.165, p = 0.011), chronic bronchitis (HR 2.179, p < 0.001), peptic ulcer disease (HR 1.531, p = 0.024) and cancer (HR 1.797, p < 0.001). Surprisingly, asthma has the opposite effect on survival time (HR 0.574, p = 0.024), but we believe this may be due to an overrepresentation of mild to moderate asthma and its management, which includes educating patients about a healthy lifestyle.

CONCLUSION

In the LIFE-Adult-Study, common risk factors and several diseases had relevant effect on overall survival. However, selection bias in epidemiological studies needs to be considered whenever interpreting results of epidemiological cohort studies. Nevertheless it was shown that the general cause-and-effect principles also apply in this relatively healthy cohort.

The upregulation of circFNDC3B aggravates the recurrence after endoscopic submucosal dissection (ESD) in early gastric cancer (EGC) patients

It has been reported that the expression of CD44 variant 9 could be utilized as a predictive marker for the recurrence in early gastric cancer (EGC) after endoscopic submucosal dissection (ESD). And circFNDC3B was proved to increase the migration and invasion of gastric cancer (GC) cells. In this study, we recruited 96 EGC patients after ESD treatment and grouped them into High circFNDC3B expression group (High expression group) and Low circFNDC3B expression group (Low expression group). Accordingly, we found that the recurrence-free rate in the High expression group was lower than that in the Low expression group. In the High expression group, the relative expression of miR-942 and miR-510 was both suppressed while the relative expression of CDH1 mRNA and CD44 mRNA/protein was increased compared with those in the Low expression group. CircFNDC3B was found to target miR-942 and miR-510 and suppress their expressions respectively. Moreover, miR-942 was found to target CD44 mRNA while miR-510 was found to target CDH1 mRNA. The overexpression of circFNDC3B led to the down-regulation of miR-942 and miR-510, which accordingly resulted in the up-regulation of CD44 and CDH1 in MKN28 cells. Moreover, we found H. pylori infection could promote the expression of circFNDC3B, which also resulted in up-regulated CD44 and CDH1 mRNA level in rTip-α cultivated MKN28 cells. In summary, our study demonstrated that a higher level of circFNDC3B could lead to the increased expression of CD44 and CDH1 via modulating the signaling pathways of miR-942/CD44 and miR-510/CDH1 in EGC patients. And the up-regulation of CD44 and CDH1 would accordingly result in a higher recurrence rate of EGC patients treated by ESD.

Helicobacter Pylori Variants with ABC-Type Tyrosine Phosphorylation Motif in Gastric Biopsies of Ghanaian Patients

BACKGROUND

Helicobacter pylori pathogenicity and disease severity are determined by the tyrosine phosphorylation motifs of CagA protein. This study is aimed at detecting the presence of H. pylori and identifying the CagA tyrosine phosphorylation motifs in Ghanaian patients. Material and Methods. A total of 94 archival genomic DNA samples from gastric biopsies were used for the study, and H. pylori was detected by amplifying the 16S rRNA gene. The 3'-end variable region of the cagA gene was amplified, and the entire 3'-end was sequenced and translated into amino acids.

RESULTS

H. pylori was detected in 53.2% (50/94) of the samples, and all the detected bacteria harboured the cagA gene. Two variants of the bacteria were identified based on the size of the amplified cagA gene: 207 bp and 285 bp. The 207 bp and 285 bp variants accounted for 74% and 22%, respectively, and 4% showed both fragments. Translated amino acid sequence of the cagA gene showed EPIYA-A, EPIYA-B, and EPIYA-C (ABC type) motifs, indicating the Western variant. The CagA protein C-terminal showed insertion of amino acids in the sequence flanking the EPIYA-A motif at the N-terminal and a complete deletion of the EPIYA-CC and EPIYA-CCC motifs together with the flanking sequences.

CONCLUSIONS

H. pylori identified were Western variant (ABC type) with unique amino acid insertions, suggesting unique variants in Ghanaian patients. Further investigation is however required to understand the role of the molecular diversity of the variant in gastric disease outcome.

Red and processed meat consumption and cancer outcomes: Umbrella review

The purpose of this umbrella review was to evaluate the quality of evidence, validity and biases of the associations between red and processed meat consumption and multiple cancer outcomes according to existing systematic reviews and meta-analyses. The umbrella review identified 72 meta-analyses with 20 unique outcomes for red meat and 19 unique outcomes for processed meat. Red meat consumption was associated with increased risk of overall cancer mortality, non-Hodgkin lymphoma (NHL), bladder, breast, colorectal, endometrial, esophageal, gastric, lung and nasopharyngeal cancer. Processed meat consumption might increase the risk of overall cancer mortality, NHL, bladder, breast, colorectal, esophageal, gastric, nasopharyngeal, oral cavity and oropharynx and prostate cancer. Dose-response analyses revealed that 100 g/d increment of red meat and 50 g/d increment of processed meat consumption were associated with 11%-51% and 8%-72% higher risk of multiple cancer outcomes, respectively, and seemed to be not correlated with any benefit.

Recent Advances in the Definition and Management of Functional Dyspepsia

In 2016, the Rome criteria were updated as Rome IV, and only minor changes were introduced for functional dyspepsia (FD). The major symptoms of FD now include not only postprandial fullness, but also epigastric pain and burning, and early satiation at above the "bothersome" level. Investigations into the effect of meal ingestion on symptom generation have indicated that not only postprandial fullness and early satiety but also epigastric pain and burning sensation and nausea (not vomiting) may increase after meals. Helicobacter pylori infection is considered to be the cause of dyspepsia if successful eradication leads to sustained resolution of symptoms for more than 6 months, and such a condition has been termed H. pylori-associated dyspepsia. Prompt esophagogastroduodenoscopy and H. pylori "test and treat" may be beneficial, especially in regions with a high prevalence of gastric cancer, such as east Asia. In terms of treatment, acotiamide, tandospirone, and rikkunshito are newly listed in Rome IV as treatment options for FD. Clinical studies in the field of FD should be strictly based on the Rome IV criteria until the next Rome V is published in 2026.

The PI3K/Akt/mTOR signaling pathway in gastric cancer; from oncogenic variations to the possibilities for pharmacologic interventions

Genetic and epigenetic alterations have been under concentrated investigations for many years in order to unearth the molecules regulating human cancer pathogenesis. However, the identification of a wide range of dysregulated genes and their protein products has raised a question regarding how the results of this large collection of alterations could converge into a formation of one malignancy. The answer may be found in the signaling cascades that regulate the survival and metabolism of the cells. Aberrancies of each participant molecule of such cascades may well result in augmented viability and unlimited proliferation of cancer cells. Among various signaling pathways, the phosphatidylinositol-3-kinase (PI3K) axis has been shown to be activated in about one-third of human cancers. One of the malignancies that is mostly affected by this axis is gastric cancer (GC), one of the most fatal cancers worldwide. In the present review, we aimed to illustrate the significance of the PI3K/Akt/mTOR axis in the pathogenesis of GC and also provided a wide perspective about the application of the inhibitors of this axis in the therapeutic strategies of this malignancy.

Differences and similarities between cancer and somatic stem cells: therapeutic implications

Over the last decades, the cancer survival rate has increased due to personalized therapies, the discovery of targeted therapeutics and novel biological agents, and the application of palliative treatments. Despite these advances, tumor resistance to chemotherapy and radiation and rapid progression to metastatic disease are still seen in many patients. Evidence has shown that cancer stem cells (CSCs), a sub-population of cells that share many common characteristics with somatic stem cells (SSCs), contribute to this therapeutic failure. The most critical properties of CSCs are their self-renewal ability and their capacity for differentiation into heterogeneous populations of cancer cells. Although CSCs only constitute a low percentage of the total tumor mass, these cells can regrow the tumor mass on their own. Initially identified in leukemia, CSCs have subsequently been found in cancers of the breast, the colon, the pancreas, and the brain. Common genetic and phenotypic features found in both SSCs and CSCs, including upregulated signaling pathways such as Notch, Wnt, Hedgehog, and TGF-β. These pathways play fundamental roles in the development as well as in the control of cell survival and cell fate and are relevant to therapeutic targeting of CSCs. The differences in the expression of membrane proteins and exosome-delivered microRNAs between SSCs and CSCs are also important to specifically target the stem cells of the cancer. Further research efforts should be directed toward elucidation of the fundamental differences between SSCs and CSCs to improve existing therapies and generate new clinically relevant cancer treatments.

Individual and synergistic protective properties of Salvia officinalis decoction extract and sulfasalazine against ethanol-induced gastric and small bowel injuries

The present study was carried out to determine the phytochemical composition of Salvia officinalis flowers decoction extract (SOFDE) as well as its individual and/or synergistic actions with sulfasalazine against ethanol (EtOH)-induced peptic ulcer in Wistar rats. In this respect, rats were divided into six groups of eight animals each: control, EtOH, EtOH + sulfasalazine (SULF, 100 mg kg^-1, b.w., p.o.), mixture: MIX (SOFDE, 50 mg kg^-1 b.w., p.o. + SULF, 50 mg kg^-1, b.w., p.o.) and EtOH + two doses of SOFDE (100 and 200 mg kg^-1 b.w., p.o.). In vitro, the phytochemical and the antioxidant properties were determined using colorimetric analysis. HPLC-PDA/ESI-MS assay was used to identify the distinctive qualitative profile of phenolic compounds. Our results firstly indicated that SOFDE is rich in total tannins, flavonols, anthocyanins and a moderate concentration of total carotenoids. Chromatographic techniques allowed the identification of 13 phenolic compounds and the major ones are quinic acid, protocatechuic acid, gallic acid and salviolinic acid. SOFDE also exhibited an important in vitro antioxidant activity using the β-carotene bleaching method. In vivo, SOFDE and the mixture provide significant protection against ethanol-induced gastric and duodenal macroscopic and histological alterations. Also, SOFDE alone or in combination with SULF, showed a significant protection against the secretory profile disturbances, lipid peroxidation, antioxidant enzyme activities and non-enzymatic antioxidant level depletion induced by alcohol administration. Importantly, we showed that EtOH acute intoxication increased gastric and intestinal calcium, free iron, magnesium and hydrogen peroxide (H₂O₂) levels, while SOFDE/MIX treatment protected against all these intracellular mediators' deregulation. We also showed that alcohol treatment significantly increased the C-reactive protein (CRP) and alkaline phosphatase (ALP) activities in plasma. The SOFDE and MIX treatment significantly protected against alcohol-induced inflammation. More importantly, we showed in the present work that the mixture exerted a more important effect than SOFDE and SULF each alone indicating a possible synergism between these two molecules. In conclusion, our data suggests that SOFDE and SULF exerted a potential synergistic protective effect against all the macroscopic, histological and biochemical disturbances induced by EtOH intoxication. This protection might be related in part to its antioxidant and anti-inflammatory properties as well as by negatively regulating Fenton reaction components such as H₂O₂ and free iron.

Syzygium aromaticum L.: Traditional herbal medicine against cagA and vacA toxin genes-producing drug resistant Helicobacter pylori

The Pan-Drug Resistant (PDR), Helicobacter pylori remains an intractable challenge in public health worldwide and this pathogenicity is mainly due to the presence of a cytotoxin-associated gene A (CagA) and vacuolating cytotoxin A (VacA). On the other hand, plant extracts such as Syzygium aromaticum contain a diverse array of secondary metabolites, which could be potentially used to combat H. pylori pathogens. To our knowledge, this is the first report on the biomedical potential of S. aromaticum extract against cytotoxin-associated genes producing PDR H. pylori. In this investigation, out of 45 gastric antral biopsy specimens of dyspeptic patients, 20 strains were confirmed as H. pylori. Eight (40%) out of 20 strains were PDR H. pylori while the rest of the strains were Multi-Drug Resistant (MDR) strains. Genotypic analyses of PDR H. pylori strains showed that cagA and vacA genes were found to be 75% and 87.5%, respectively and m2s2 was the most common subtype of vacA gene. S. aromaticum showed a significant higher anti-H. pylori activity compared to that of Cinnamomum zeylanicum and Thymus vulgaris. Eugenol was the major phenolic compound (28.14%) detected in the methanolic extract of S. aromaticum. Clearly, results of the toxicological assessment confirmed the safety of S. aromaticum for use. Hence, these results suggest that S. aromaticum could be a new useful natural antimicrobial agent that could potentially combat cytotoxin genes-producing drug-resistant H. pylori. Moreover, these findings provide a scientific basis for the development of antimicrobial agents from traditional herbal medicines for gastroprotection against gastric ulcer.

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Helicobacter pylori remains an intractable challenge in public health worldwide.

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CagA and VacA genes are H. pylori pathogenicity dependent.

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Eight strains of H. pylori were proven to pan-drug resistant.

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The cagA and vacA genes were found to be 75% and 87.5%, respectively.

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Syzygium aromaticum extract showed a significant higher anti-H. pylori activity.

Effect of Red, Processed, and White Meat Consumption on the Risk of Gastric Cancer: An Overall and Dose⁻Response Meta-Analysis

Whether the risk of gastric cancer varies by the types of meat consumption still remains disputable. The purpose of this meta-analysis was to identify the exact associations that red, processed, and white meat have with gastric cancer. We searched relevant studies in Medline, EMBASE, and the Cochrane Library before November 2018, including cohort and case-control studies. We used random-effect models to estimate the adjusted relative risk (RR), and Egger’s tests to evaluate publication bias. Through stepwise screening, 43 studies were included in this analysis (11 cohort studies and 32 case-control studies with 16,572 cases). In a meta-analysis for the highest versus lowest categories of meat consumption, both red (RR: 1.41, 95% confidence interval (CI): 1.21–1.66) and processed (RR: 1.57, 95% CI: 1.37–1.81) meat consumption were positively associated with gastric cancer risk, while white meat consumption was negatively associated with gastric cancer risk (RR: 0.80, 95% CI: 0.69–0.92). In a dose–response meta-analysis, the RRs of gastric cancer were 1.26 (95% CI: 1.11–1.42) for every 100 g/day increment in red meat consumption, 1.72 (95% CI: 1.36–2.18) for every 50 g/day increment in processed meat consumption, and 0.86 (95% CI: 0.64–1.15) for every 100 g/day increment in white meat consumption. The increase of white meat consumption may reduce the risk of gastric cancer, while red or processed meat may increase the risk of gastric cancer. Further studies are required to identify these associations, especially between white meat and gastric cancer.

CAPZA1 determines the risk of gastric carcinogenesis by inhibiting Helicobacter pylori CagA-degraded autophagy

Helicobacter pylori-derived CagA, a type IV secretion system effector, plays a role as an oncogenic driver in gastric epithelial cells. However, upon delivery into gastric epithelial cells, CagA is usually degraded by macroautophagy/autophagy. Hence, the induction of autophagy in H. pylori-infected epithelial cells is an important host-protective ability against gastric carcinogenesis. However, the mechanisms by which autophagosome-lysosome fusion is regulated, are unknown. Here, we report that enhancement of LAMP1 (lysosomal associated membrane protein 1) expression is necessary for autolysosome formation. LAMP1 expression is induced by nuclear translocated LRP1 (LDL receptor related protein 1) intracellular domain (LRP1-ICD) binding to the proximal LAMP1 promoter region. Nuclear translocation of LRP1-ICD is enhanced by H. pylori infection. In contrast, CAPZA1 (capping actin protein of muscle Z-line alpha subunit 1) inhibits LAMP1 expression via binding to LRP1-ICD in the nuclei. The binding of CAPZA1 to LRP1-ICD prevents LRP1-ICD binding to the LAMP1 proximal promoter. Thus, in CAPZA1-overexpressing gastric epithelial cells infected with H. pylori, autolysosome formation is inhibited and CagA escapes autophagic degradation. These findings identify CAPZA1 as a novel negative regulator of autolysosome formation and suggest that deregulation of CAPZA1 expression leads to increased risk of gastric carcinogenesis. Abbreviations: CagA: cytotoxin-associated gene A; CAPZA1: capping actin protein of muscle Z-line alpha subunit 1; ChIP: chromatin immunoprecipitation; GTF2I: general transcription factor IIi; HDAC: histone deacetylase; LAMP1: lysosomal associated membrane protein 1; LRP1: LDL receptor related protein 1; LRP1-ICD: CagA intracellular domain; qPCR: quantitative polymerase chain reaction; VacA: vacuolating cytotoxin.

High FNDC1 expression correlates with poor prognosis in gastric cancer

Gastric cancer is a common human cancer worldwide. Fibronectin is an important extracellular matrix protein that has been implicated in many cancers and is known to be associated with proliferation and migration. Fibronectin type III domain containing 1 (FNDC1) contains a major component of the structural domain of fibronectin. The objectives of the present study were to measure FNDC1 expression in gastric cancer tissues and evaluate its value as a potential prognostic marker for gastric cancer. FNDC1 protein expression was analyzed by immunohistochemistry in 98 samples of gastric cancer tissue and 25 adjacent normal tissues. The associations between FNDC1 level and various clinicopathological characteristics were assessed, and the correlation between FNDC1 expression levels and prognosis of patients with gastric cancer was analyzed using a Kaplan-Meier analysis. It was demonstrated that FNDC1 expression in gastric cancer tissues and adjacent tissues was significantly different. FNDC1 expression levels were significantly higher in gastric cancer tissues compared with normal gastric tissues (P<0.001). Among the clinicopathological characteristics evaluated, clinical stage (P<0.001), T classification (P<0.001), N classification (P<0.001) and pathological differentiation (P=0.044) were significantly associated with high FNDC1 expression. Higher FNDC1 expression level was significantly correlated with poorer survival. The present findings suggest that FNDC1 expression levels may be a promising prognostic biomarker for gastric cancer.

Clinicopathologic implications of immune classification by PD-L1 expression and CD8-positive tumor-infiltrating lymphocytes in stage II and III gastric cancer patients

We co-assessed PD-L1 expression and CD8⁺ tumor-infiltrating lymphocytes in gastric cancer (GC), and categorized into 4 microenvironment immune types. Immunohistochemistry (PD-L1, CD8, Foxp3, E-cadherin, and p53), PD-L1 mRNA in situ hybridization (ISH), microsatellite instability (MSI), and EBV ISH were performed in 392 stage II/III GCs treated with curative surgery and fluoropyrimidine-based adjuvant chemotherapy, and two public genome databases were analyzed for validation. PD-L1⁺ was found in 98/392 GCs (25.0%). The proportions of immune types are as follows: PD-L1⁺/CD8^High, 22.7%; PD-L1⁻/CD8^Low, 22.7%; PD-L1⁺/CD8^Low, 2.3%; PD-L1⁻/CD8^High, 52.3%. PD-L1⁺/CD8^High type accounted for majority of EBV⁺ and MSI-high (MSI-H) GCs (92.0% and 66.7%, respectively), and genome analysis from public datasets demonstrated similar pattern. PD-L1⁻/CD8^High showed the best overall survival (OS) and PD-L1⁻/CD8^Low the worst (P < 0.001). PD-L1 expression alone was not associated with OS, however, PD-L1⁻/CD8^High type compared to PD-L1⁺/CD8^High was independent favorable prognostic factor of OS by multivariate analysis (P = 0.042). Adaptation of recent molecular classification based on EBV, MSI, E-cadherin, and p53 showed no significant survival differences. These findings support the close relationship between PD-L1/CD8 status based immune types and EBV⁺, MSI-H GCs, and their prognostic significance in stage II/III GCs.

Is There a Correlation between Helicobacter Pylori and Enterohepatic Helicobacter Species and Gallstone Cholecystitis?

BACKGROUND

Cholecystitis is a common surgical condition. Recently, several authors have reported that DNA of bile tolerant Helicobacter spp. has been found in the human bile colonizing the biliary tract. The aim of this study was to evaluate the association between the presence of Helicobacter spp. and gallstone cholecystitis.

METHODS

In this case-control study, gallstones, bile, and gallbladder mucosa were collected from 25 patients without gallstone disease, 24 with acute cholecystitis, and 28 with chronic cholecystitis. The presence of Helicobacter pylori (H. pylori), Helicobacter bilis (H. bilis), Helicobacter hepaticus (H. hepaticus) , and Helicobacter pullorum (H. pullorum) were investigated by polymerase chain reaction (PCR) using species-specific primers.

RESULTS

In this study, 77 subjects with acute and chronic cholecystitis and control groups with a mean age of 46.85 ± 14.53 years, including 58 (67.25%) women and 19 (32.75%) men were included. DNA of 10 Helicobacter spp. was detected in the bile of the patients with cholecystitis including eight H. pylori and two H. bilis. However, we could not detect H. hepaticus and H. pullorum DNA in the samples. Moreover, there was an association between H. pylori and acute cholecystitis (p = 0.048), which was found to be stronger in 31-40-year-olds group (p = 0.003).

CONCLUSION

We found an association between the presence of H. pylori DNA and acute gallstone cholecystitis. There is not statistically significant correlation between three enterohepatic Helicobacter spp. ( H. bilis, H. hepaticus , and H. pullorum) and cholelithiasis. Given the low sample size of the patients, more studies are required to clear the clinical role of Helicobacter spp. in the gallstone disease and cholecystitis.

Downregulation of liver-intestine cadherin enhances cisplatin-induced apoptosis in human gastric cancer BGC823 cells

Gastric cancer is the fourth most common type of cancer. Liver-intestine cadherin (CDH17) has been found to be involved in the proliferation and apoptosis of gastric cancer cells. Cisplatin is one of the most widely used antineoplastic agents in the treatment of solid tumor and hematological malignancies. However, the mechanism of enhancing cisplatin-inducing effects on human gastric cancer BGC823 cells by blocking CDH17 gene, both in vitro and in vivo, remains to be clarified. In this study, we investigated the signaling pathway by which cisplatin induces apoptosis by blocking CDH17 gene in gastric cancer BGC823 cells. Our results indicate that down-expression of CDH17 gene can enhance apoptosis-inducing effects of cisplatin on human gastric cancer BGC823 cells. The expression levels of Bax and Cyt-c proteins were upregulated, but the expression levels of Bcl-2 and Bcl-xL proteins were downregulated by blocking CDH17 gene in gastric cancer BGC823 cells after treatment with cisplatin. Moreover, down-expression of CDH17 enhanced the efficacy of cisplatin-induced inhibition of tumor growth in nude mice via apoptosis induction. Down-expression of CDH17 gene can significantly improve apoptosis-inducing effects of cisplatin in vitro and in vivo, which is a new strategy to improve chemotherapeutic effects on gastric cancer.

PTEN Gene Induces Cell Invasion and Migration via Regulating AKT/GSK-3β/β-Catenin Signaling Pathway in Human Gastric Cancer

BACKGROUND

Abnormality of PTEN gene and Wnt/β-catenin signaling have been strongly implicated in various malignant cancers. Recently, it has been noted that a functional interaction/cross-talk was found between the PTEN/PI3K/AKT and Wnt/β-catenin, which plays a key role in the development of cancers. However, few related studies on gastric cancer are available.

AIM

We examined the expression of PTEN and β-catenin in gastric cancer tissues and detected whether down-regulation of PTEN promotes the migration and invasion in gastric cancer cells along with its underlying mechanism.

MATERIALS AND METHODS

Immunocytochemistry, a wound healing assay, a Matrigel invasion assay, an immunofluorescence staining were performed to detect expression of PTEN and β-catenin in gastric cancer and adjacent normal tissues, cell migration, cell invasion, and the effects of PTEN knockdown on β-catenin in cells, respectively. Further, MMP-2 and MMP-9 activities were analyzed by zymography assay. The changes in related proteins were further quantified by western blotting.

RESULTS

Low expression of PTEN was found in majority of gastric cancer tissues, which showed significant associations with differentiation grade in gastric cancer patients. Further, a negative correlation was revealed between PTEN and β-catenin protein expression in gastric cancer tissues (r = - 0.546, P < 0.01). Additionally, PTEN knockdown promoted the migration and invasion of cells and caused an obvious increase in p-AKT, p-GSK-3β, β-catenin, E-cadherin, MMP-7, MMP-2, and MMP-9 in gastric cancer cells.

CONCLUSION

Our results indicated PTEN gene might induce cell invasion and migration via regulating AKT/GSK-3β/β-catenin signaling pathway, playing a vital role in the progression of gastric cancer.

Insulin-like growth factor binding protein-1 (IGFBP-1) upregulated by Helicobacter pylori and is associated with gastric cancer cells migration

Insulin-like growth factor binding protein-1 (IGFBP-1), a secreted protein, implicated of various cells in mediating the proliferation, migration, invasion, adhesion, survival and so on. In this study, we assessed the expression and release of IGFBP-1 from gastric cancer cells with H. pylori 26695 infection and the biological functions of IGFBP-1 in gastric cancer cells. The results showed that the expression and release of IGFBP-1 were increased in gastric cancer cells (MGC-803, BGC-823, SGC-7901) infected with H. pylori 26695. In addition, the upregulation of IGFBP-1 was dose-dependent in BGC-823 cells infected with H. pylori 26695 but not time-dependent. The upregulation of IGFBP-1 got to peak at 12h after H. pylori 26695 infection and then decreased over time. Subsequently, we measured its functions by silencing and overexpressing IGFBP1 which suggested that overexpression of IGFBP-1 could inhibit the migration of BGC-823 and SGC-7901 cells. However, knocking down the IGFBP-1 could increase the migration of BGC-823 and SGC-7901 cells. Functional findings illustrated that IGFBP-1 was implicated in H. pylori 26695-induced MMP-9 expression in BGC-823 cells. In addition, overexpressing IGFBP1 reduce the promoting effect of MMP-9 on the BGC-823 cells migration. In summary, we demonstrated that IGFBP-1 suppress the migration of BGC-823 cells and play a protective role in the process of H. pylori-induced gastric cancer.

The Application of the Rome IV Criteria to Functional Esophagogastroduodenal Disorders in Asia

The Rome criteria were amended as Rome IV. For functional esophageal disorders, the exclusion criteria have been more specifically revised based on further understanding of other esophageal disorders, including eosinophilic esophagitis and spastic and hypercontractile motor disorders. Another revised point is the more restrictive definition of gastroesophageal reflux disease, indicating that sensitivity to a physiological reflux burden may be placed more firmly within the functional group. For functional dyspepsia (FD), only minor changes were introduced, mainly to improve specificity. Among the major symptoms of FD, not only postprandial fullness, but also epigastric pain, epigastric burning, and early satiation should be "bothersome." Investigation on the effect of meal ingestion on symptom generation has indicated that not only postprandial fullness and early satiety, but also epigastric pain, epigastric burning sensation and nausea (not vomiting) may increase after meals. Helicobacter pylori infection is considered a possible cause of dyspepsia if successful eradication leads to sustained resolution of symptoms for more than 6 months, and such status can be termed as "H. pylori-associated dyspepsia." Prompt esophagogastroduodenoscopy and H. pylori testing and treatment would be more beneficial, especially in Asia, which has a high prevalence of gastric cancer. Acotiamide, tandospirone, and rikkunshito are the newly listed as treatment options for FD. For further therapeutic development, clinical studies based on the strict Rome IV criteria should be performed.

Gastric cancer and family history

Gastric cancer is associated with high morbidity and mortality rates worldwide. Identifying individuals at high risk is important for surveillance and prevention of gastric cancer. Having first-degree relatives diagnosed with gastric cancer is a strong and consistent risk factor for gastric cancer, but the pathogenic mechanisms behind this familial aggregation are unclear. Against this background, we reviewed the risk factors for gastric cancer in those with a first-degree relative with gastric cancer, and the possible causes for familial clustering of gastric cancer including bacterial factors, inherited genetic susceptibility, environmental factors or a combination thereof. Among individuals with a family history, current or past Helicobacter pylori infection, having two or more first-degree affected relatives or female gender was associated with an increased risk of developing gastric cancer. To date, no specific single nucleotide polymorphism has been shown to be associated with familial clustering of gastric cancer. H. pylori eradication is the most important strategy for preventing gastric cancer in first-degree relatives of gastric cancer patients, particularly those in their 20s and 30s. Early H. pylori eradication could prevent the progression to intestinal metaplasia and reduce the synergistic effect on gastric carcinogenesis in individuals with both H. pylori infection and a family history. Endoscopic surveillance is also expected to benefit individuals with a family history. Further large-scale, prospective studies are warranted to evaluate the cost-effectiveness and optimal time point for endoscopy in this population. Moreover, genome-wide association studies that incorporate environmental and dietary factors on a 'big data' basis will increase our understanding of the pathogenesis of gastric cancer.

Hostile takeover: Manipulation of HIF-1 signaling in pathogen-associated cancers (Review)

Hypoxia-inducible factor (HIF)-1 is a central regulator in the adaptation process of cell response to hypoxia (low oxygen). Emerging evidence has demonstrated that HIF-1 plays an important role in the development and progression of many types of human diseases, including pathogen-associated cancers. In the present review, we summarize the recent understandings of how human pathogenic agents including viruses, bacteria and parasites deregulate cellular HIF-1 signaling pathway in their associated cancer cells, and highlight the common molecular mechanisms of HIF-1 signaling activated by these pathogenic infection, which could act as potential diagnostic markers and new therapeutic strategies against human infectious cancers.

Recent developments and innovations in gastric cancer

Gastric cancer has an important place in the worldwide incidence of cancer and cancer-related deaths. It can metastasize to the lymph nodes in the early stages, and lymph node metastasis is an important prognostic factor. Surgery is a very important part of gastric cancer treatment. A D2 lymphadenectomy is the standard surgical treatment for cT1N+ and T2-T4 cancers, which are potentially curable. Recently, the TNM classification system was reorganized, and the margins for gastrectomy and lymphadenectomy were revised. Endoscopic, laparoscopic and robotic treatments of gastric cancer have progressed rapidly with development of surgical instruments and techniques, especially in Eastern countries. Different endoscopic resection techniques have been identified, and these can be divided into two main categories: endoscopic mucosal resection and endoscopic submucosal dissection. Minimally invasive surgery has been reported to be safe and effective for early gastric cancer, and it can be successfully applied to advanced gastric cancer with increasing experience. Cytoreductive surgery and hyperthermıc intraperıtoneal chemotherapy were developed as a combined treatment modality from the results of experimental and clinical studies. Also, hyperthermia increases the antitumor activity and penetration of chemotherapeutics. Trastuzumab which is a monoclonal antibody interacts with human epidermal growth factor (HER) 2 and is related to gastric carcinoma. The anti-tumor mechanism of trastuzumab is not clearly known, but mechanisms such as interruption of the HER2-mediated cell signaling pathways and cell cycle progression have been reported previously. H. pylori is involved in 90% of all gastric malignancies and Japanese guidelines strongly recommend that all H. pylori infections should be eradicated regardless of the associated disease. In this review, we present innovations discussed in recent studies.

Familial Clustering of Gastric Cancer: A Retrospective Study Based on the Number of First-Degree Relatives

This comprehensive cross-sectional study aimed to identify factors contributing to familial aggregation of gastric cancer (GC). A total of 1058 GC patients and 1268 controls were analyzed separately according to the presence or absence of a first-degree relative of GC (GC-relative). Logistic regression analysis adjusted for age, gender, residence during childhood, smoking, alcohol intake, monthly income, spicy food ingestion, Helicobacter pylori status and host cytokine polymorphisms was performed. Cytotoxin-associated gene A (cagA) positivity was a distinctive risk factor for GC in the family history (FH)-positive group (odds ratio [OR], 2.39; 95% confidence interval [CI], 1.42-4.00), while current/ex-smoker, moderate to strong spicy food ingestion, and non-B blood types were more closely associated with GC in the FH-negative group. Among the FH-positive group, alcohol consumption showed a synergistic carcinogenic effect in the at least 2 GC-relatives group compared to the 1 GC-relative group (1.71 vs. 9.58, P for interaction = 0.026), and this was dose-dependent. In the subjects with ≥2 GC-relatives, TGFB1-509T/T was a risk factor for GC (OR 23.74; 95% CI 1.37-410.91), as were rural residency in childhood, alcohol consumption, spicy food ingestion, and cagA positivity. These results suggest that subjects with FH may be a heterogeneous group in terms of gastric cancer susceptibility. Especially, subjects with ≥2 GC-relatives should undergo risk stratification including TGFB1-509T/T and alcohol consumption.

Helicobacter pylori eradication therapy for functional dyspepsia: Systematic review and meta-analysis

AIM: To evaluate whether Helicobacter pylori (H. pylori) eradication therapy benefits patients with functional dyspepsia (FD).

METHODS: Randomized controlled trials (RCTs) investigating the efficacy and safety of H. pylori eradication therapy for patients with functional dyspepsia published in English (up to May 2015) were identified by searching PubMed, EMBASE, and The Cochrane Library. Pooled estimates were measured using the fixed or random effect model. Overall effect was expressed as a pooled risk ratio (RR) or a standard mean difference (SMD). All data were analyzed with Review Manager 5.3 and Stata 12.0.

RESULTS: This systematic review included 25 RCTs with a total of 5555 patients with FD. Twenty-three of these studies were used to evaluate the benefits of H. pylori eradication therapy for symptom improvement; the pooled RR was 1.23 (95%CI: 1.12-1.36, P < 0.0001). H. pylori eradication therapy demonstrated symptom improvement during long-term follow-up at ≥ 1 year (RR = 1.24; 95%CI: 1.12-1.37, P < 0.0001) but not during short-term follow-up at < 1 year (RR = 1.26; 95%CI: 0.83-1.92, P = 0.27). Seven studies showed no benefit of H. pylori eradication therapy on quality of life with an SMD of -0.01 (95%CI: -0.11 to 0.08, P = 0.80). Six studies demonstrated that H. pylori eradication therapy reduced the development of peptic ulcer disease compared to no eradication therapy (RR = 0.35; 95%CI: 0.18-0.68, P = 0.002). Eight studies showed that H. pylori eradication therapy increased the likelihood of treatment-related side effects compared to no eradication therapy (RR = 2.02; 95%CI: 1.12-3.65, P = 0.02). Ten studies demonstrated that patients who received H. pylori eradication therapy were more likely to obtain histologic resolution of chronic gastritis compared to those who did not receive eradication therapy (RR = 7.13; 95%CI: 3.68-13.81, P < 0.00001).

CONCLUSION: The decision to eradicate H. pylori in patients with functional dyspepsia requires individual assessment.

hTERT mediates gastric cancer metastasis partially through the indirect targeting of ITGB1 by microRNA-29a

Human telomerase reverse transcriptase (hTERT) plays a key role in tumor invasion and metastasis, but the mechanism of its involvement in these processes is not clear. The purpose of this study is to investigate the possible molecular mechanism of hTERT in the promotion of gastric cancer (GC) metastasis. We found that the up-regulation of hTERT in gastric cancer cells could inhibit the expression of miR-29a and enhance the expression of Integrin β1 (ITGB1). In addition, the invasive capacity of gastric cancer cells was also highly increased after hTERT overexpression. Our study also found that the restoration of miR-29a suppressed the expression of ITGB1 and inhibited GC cell metastasis both in vitro and in vivo. Taken together, our results suggested that hTERT may promote GC metastasis through the hTERT-miR-29a-ITGB1 regulatory pathway.

Helicobacter pylori in gastric carcinogenesis

Gastric cancer still is a major concern as the third most common cancer worldwide, despite declining rates of incidence in many Western countries. Helicobacter pylori (H. pylori) is the major cause of gastric carcinogenesis, and its infection insults gastric mucosa leading to the occurrence of atrophic gastritis which progress to intestinal metaplasia, dysplasia, early gastric cancer, and advanced gastric cancer consequently. This review focuses on multiple factors including microbial virulence factors, host genetic factors, and environmental factors, which can heighten the chance of occurrence of gastric adenocarcinoma due to H. pylori infection. Bacterial virulence factors are key components in controlling the immune response associated with the induction of carcinogenesis, and cagA and vacA are the most well-known pathogenic factors. Host genetic polymorphisms contribute to regulating the inflammatory response to H. pylori and will become increasingly important with advancing techniques. Environmental factors such as high salt and smoking may also play a role in gastric carcinogenesis. It is important to understand the virulence factors, host genetic factors, and environmental factors interacting in the multistep process of gastric carcinogenesis. To conclude, prevention via H. pylori eradication and controlling environmental factors such as diet, smoking, and alcohol is an important strategy to avoid H. pylori-associated gastric carcinogenesis.

Relationship between body mass index and the risk of early gastric cancer and dysplasia regardless of Helicobacter pylori infection

BACKGROUND

Obesity is known to be associated with an increased risk of gastric cardia cancer but not with noncardia cancer. In terms of gastric dysplasia, few studies have evaluated its relationship with obesity. In addition, no study on the relationship between obesity and the risk of gastric cancer has analyzed the status of Helicobacter pylori infection.

METHODS

A case-control study was designed to investigate the relationship between obesity and the risk of gastric cancer and dysplasia adjusted for the status of H. pylori infection in Koreans. Nine hundred ninety-eight gastric cancer patients, 313 gastric dysplasia patients, and 1,288 subjects with normal endoscopic findings were included.

RESULTS

As gender differences could be the largest confounding factor, the risk of gastric cancer and dysplasia with an increasing body mass index (BMI) was analyzed in men and women, separately, and was adjusted for age, smoking, drinking, family history of gastric cancer, H. pylori infection, atrophic gastritis, intestinal metaplasia, and serum pepsinogen I/pepsinogen II ratio. Obesity (BMI 25 kg/m(2) or greater but less than 30 kg/m(2)) was associated with increased risk of early gastric cancer [adjusted odds ratio (aOR) 1.657; 95 % confidence interval (CI) 1.086-2.528; P = 0.019] and well or moderately differentiated adenocarcinoma (aOR 1.566; 95 % CI 1.011-2.424; P = 0.044) compared with normal BMI status (BMI < 23 kg/m(2)) in men. Obesity was related to gastric dysplasia (aOR 2.086; 95 % CI 1.011-4.302; P = 0.047) in women.

CONCLUSIONS

The effect of obesity on gastric cancer showed a gender difference. That is, in men it was related to increased risk of early gastric cancer and well or moderately differentiated adenocarcinoma, but it was associated with gastric dysplasia in women regardless of H. pylori infection in Korea. Further research into this difference is necessary.

Helicobacter pylori Infection in Thailand: A Nationwide Study of the CagA Phenotype

Background

The risk to develop gastric cancer in Thailand is relatively low among Asian countries. In addition, the age-standardized incidence rate (ASR) of gastric cancer in Thailand varies with geographical distribution; the ASR in the North region is 3.5 times higher than that in the South region. We hypothesized that the prevalence of H. pylori infection and diversity of CagA phenotype contributes to the variety of gastric cancer risk in various regions of Thailand.

Methods

We conducted a nationwide survey within Thailand. We determined H. pylori infection prevalence by detecting H. pylori, using histochemical and immunohistochemical methods. The anti-CagA antibody and anti-East-Asian type CagA antibody (α-EAS Ab), which showed high accuracy in several East Asian countries, were used to determine CagA phenotype.

Results

Among 1,546 patients from four regions, including 17 provinces, the overall prevalence of H. pylori infection was 45.9% (710/1,546). Mirroring the prevalence of H. pylori infection, histological scores were the lowest in the South region. Of the 710 H. pylori-positive patients, 93.2% (662) were immunoreactive with the anti-CagA antibody. CagA-negative strain prevalence in the South region was significantly higher than that in other regions (17.9%; 5/28; p < 0.05). Overall, only 77 patients (11.6%) were immunoreactive with the α-EAS Ab. There were no differences in the α-EAS Ab immunoreactive rate across geographical regions.

Conclusions

This is the first study using immunohistochemistry to confirm H. pylori infections across different regions in Thailand. The prevalence of East-Asian type CagA H. pylori in Thailand was low. The low incidence of gastric cancer in Thailand may be attributed to the low prevalence of precancerous lesions. The low incidence of gastric cancer in the South region might be associated with the lower prevalence of H. pylori infection, precancerous lesions, and CagA-positive H. pylori strains, compared with that in the other regions.

Molecular Epidemiology of Helicobacter pylori Infection in Nepal: Specific Ancestor Root

Prevalence of Helicobacter pylori infection in Nepal, a low-risk country for gastric cancer, is debatable. To our knowledge, no studies have examined H. pylori virulence factors in Nepal. We determined the prevalence of H. pylori infection by using three different tests, and the genotypes of virulence factors were determined by PCR followed by sequencing. Multilocus sequence typing was used to analyze the population structure of the Nepalese strains. The prevalence of H. pylori infection in dyspeptic patients was 38.4% (56/146), and was significantly related with source of drinking water. In total, 51 strains were isolated and all were cagA-positive. Western-type-cagA (94.1%), cagA pre-EPIYA type with no deletion (92.2%), vacA s1a (74.5%), and m1c (54.9%) were the predominant genotypes. Antral mucosal atrophy levels were significantly higher in patients infected with vacA s1 than in those infected with s2 genotypes (P = 0.03). Several Nepalese strains were H. pylori recombinants with genetic features of South Asian and East Asian genotypes. These included all East-Asian-type-cagA strains, with significantly lesser activity and inflammation in the corpus than the strains of the specific South Asian genotype (P = 0.03 and P = 0.005, respectively). Although the population structure confirmed that most Nepalese strains belonged to the hpAsia2 population, some strains shared hpEurope- and Nepalese-specific components. Nepalese patients infected with strains belonging to hpEurope showed higher inflammation in the antrum than strains from the Nepalese specific population (P = 0.05). These results support that ancestor roots of Kathmandu`s people not only connected with India alone.

In vivo histopathology using endocytoscopy for non-neoplastic changes in the gastric mucosa: a prospective pilot study (with video)

BACKGROUND

Endocytoscopy (EC), as a novel ultrahigh magnification technology, enables in vivo histopathological diagnoses of the GI tract. EC is particularly exceptional when comparing dysplastic and neoplastic tissue with normal tissue. There are, however, no detailed data for minute or minimal changes in the gastric mucosa.

OBJECTIVE

To describe non-neoplastic EC patterns of the gastric mucosa correlated with histopathological findings and to determine any relationship with Helicobacter pylori (HP) infection.

DESIGN

A pilot prospective study.

SETTING

Tertiary care referral center.

PATIENTS

Sixty-four participants undergoing upper endoscopy for various indications.

METHODS

Antral mucosal patterns on EC were divided into 4 categories: type 1 (normal), each papilla/pit has round smooth structure; type 2 (gastritis), extended, notched, and distorted structure with some necrotic tissue; type 3(atrophy), neighboring papilla/pit take on a lobulated appearance; type 4 (intestinal metaplasia [IM]), goblet cells are identified in a completely stained crypt. Target biopsy specimens were obtained from the region identified with these patterns, and multiple HP tests were performed.

RESULTS

HP positivity was 0%, 40.9%, 50.0%, and 58.3% in types 1, 2, 3, and 4, respectively. The sensitivity and specificity of types 2+3+4 for HP positivity were 100％ and 42.5%, respectively. The positive predictive values of type 1 for normal, type 2 for chronic gastritis, type 3 for atrophic gastritis, and type 4 for IM were 100%, 62.5%, 40.0%, and 100%, respectively. The sensitivity and specificity of types 3+4 for atrophic gastritis to IM were 87.0% and 95.1%, respectively.

LIMITATIONS

Small, single-center, pilot study.

CONCLUSIONS

EC can differentiate gastric mucosal patterns of minimal, non-neoplastic change and appears to reliably exclude HP infection.

Total, caffeinated and decaffeinated coffee and tea intake and gastric cancer risk: results from the EPIC cohort study

Prospective studies examining the association between coffee and tea consumption and gastric cancer risk have shown inconsistent results. We investigated the association between coffee (total, caffeinated and decaffeinated) and tea consumption and the risk of gastric cancer by anatomical site and histological type in the European Prospective Investigation into Cancer and Nutrition study. Coffee and tea consumption were assessed by dietary questionnaires at baseline. Adjusted hazard ratios (HRs) were calculated using Cox regression models. During 11.6 years of follow up, 683 gastric adenocarcinoma cases were identified among 477,312 participants. We found no significant association between overall gastric cancer risk and consumption of total coffee (HR 1.09, 95%-confidence intervals [CI]: 0.84-1.43; quartile 4 vs. non/quartile 1), caffeinated coffee (HR 1.14, 95%-CI: 0.82-1.59; quartile 4 vs. non/quartile 1), decaffeinated coffee (HR 1.07, 95%-CI: 0.75-1.53; tertile 3 vs. non/tertile 1) and tea (HR 0.81, 95%-CI: 0.59-1.09; quartile 4 vs. non/quartile 1). When stratified by anatomical site, we observed a significant positive association between gastric cardia cancer risk and total coffee consumption per increment of 100 mL/day (HR 1.06, 95%-CI: 1.03-1.11). Similarly, a significant positive association was observed between gastric cardia cancer risk and caffeinated coffee consumption (HR 1.98, 95%-CI: 1.16-3.36, p-trend=0.06; quartile 3 vs. non/quartile 1) and per increment of 100 mL/day (HR 1.09, 95%-CI: 1.04-1.14). In conclusion, consumption of total, caffeinated and decaffeinated coffee and tea is not associated with overall gastric cancer risk. However, total and caffeinated coffee consumption may be associated with an increased risk of gastric cardia cancer. Further prospective studies are needed to rule out chance or confounding.

Prevalence of Helicobacter pylori infection and atrophic gastritis in patients with dyspeptic symptoms in Myanmar

AIM: To survey the detailed analyses for Helicobacter pylori (H. pylori) infection and gastric mucosal status in Myanmar.

METHODS: A total of 252 volunteers with dyspeptic symptoms (155 female and 97 male; mean age of 43.6 ± 14.2 years) was participated in Yangon and Mandalay. The status of H. pylori infection was determined based on 5 different tests including rapid urease test, culture, histology, immunohistochemistry and serology. Histological scores were evaluated according to the update Sydney system and the Operative Link for Gastritis Assessment system. Pepsinogen (PG) I and PG II were measured using enzyme-linked immunosorbent assays.

RESULTS: The overall prevalence of H. pylori infection was 48.0%. There was no relationship between age and infection rate. Even in young group (less than 29 years old), the H. pylori infection rate was relatively high (41.9%). The prevalence of H. pylori infection was significantly higher in Yangon than that of Mandalay. H. pylori infection was significantly associated with the presence of gastric mucosal atrophy. All 7 subjects with peptic ulcer were infected with H. pylori. Although H. pylori-positive subjects showed stronger gastritis than H. pylori-negative subjects, most cases had mild gastritis.

CONCLUSION: We revealed the prevalence of H. pylori infection in patients with dyspeptic symptoms in Myanmar. The H. pylori infection was a risk factor for peptic ulcer and stronger gastritis.

Do we need to eradicate Helicobacter pylori in patients with GORD?

Eradication of Helicobacter pylori should not be avoided because of complicated reflux symptoms. Previously, although H. pylori eradication in patients with GORD was considered to induce unfavourable effects that worsen reflux symptoms, recent reports indicates that it can have favourable consequences by reducing symptoms and therefore improving quality of life, especially in GORD patients without severe corpus atrophy or severe hiatal herniation.

Histological changes of gastric mucosa after Helicobacter pylori eradication: a systematic review and meta-analysis

AIM

To systematically review pathological changes of gastric mucosa in gastric atrophy (GA) and intestinal metaplasia (IM) after Helicobacter pylori (H. pylori) eradication.

METHODS

A systematic search was made of PubMed, Web of Science, EMBASE, ClinicalTrials.gov, OVID and the Cochran Library databases for articles published before March 2013 pertaining to H. pylori and gastric premalignant lesions. Relevant outcomes from articles included in the meta-analysis were combined using Review Manager 5.2 software. A Begg's test was applied to test for publication bias using STATA 11 software. χ(2) and I(2) analyses were used to assess heterogeneity. Analysis of data with no heterogeneity (P > 0.1, I (2) < 25%) was carried out with a fixed effects model, otherwise the causes of heterogeneity were first analyzed and then a random effects model was applied.

RESULTS

The results of the meta-analysis showed that the pooled weighted mean difference (WMD) with 95%CI was 0.23 (0.18-0.29) between eradication and non-eradication of H. pylori infection in antral IM with a significant overall effect (Z = 8.19; P <0.00001) and no significant heterogeneity (χ(2) = 27.54, I(2) = 16%). The pooled WMD with 95%CI was -0.01 (-0.04-0.02) for IM in the corpus with no overall effect (Z = 0.66) or heterogeneity (χ(2) = 14.87, I(2) =0%) (fixed effects model). In antral GA, the pooled WMD with 95% CI was 0.25 (0.15-0.35) with a significant overall effect (Z = 4.78; P < 0.00001) and significant heterogeneity (χ(2) = 86.12, I(2) = 71%; P < 0.00001). The pooled WMD with 95% CI for GA of the corpus was 0.14 (0.04-0.24) with a significant overall effect (Z = 2.67; P = 0.008) and significant heterogeneity (χ(2) = 44.79, I(2) = 62%; P = 0.0003) (random effects model).

CONCLUSION

H. pylori eradication strongly correlates with improvement in IM in the antrum and GA in the corpus and antrum of the stomach.

Association of CD14/-260 polymorphism with gastric cancer risk in Highland Tibetans

AIM: To investigate the relationship between CD14-260 and -651 polymorphisms and the risk of developing gastric cancer.

METHODS: DNA was extracted from peripheral blood samples obtained from 225 Tibetans with gastric cancer and 237 healthy Tibetans, and analyzed using the polymerase chain reaction/ligase detection (PCR/LDR) method to determine the genotypes at -260 and -651 loci of the CD14 promoter. The allele frequencies, genotype frequencies, and haplotypes were analyzed for their association with gastric cancer risk using online SHEsis software. The luciferase reporter assay and point mutation analysis were used to construct in vitro plasmids expressing a C/T homozygote at the -260 locus of the CD14 promoter.

RESULTS: The frequencies of CC, CT and TT genotypes in the CD14-260 C/T locus in gastric cancer patients were 19.1%, 38.7% and 42.2%, respectively, whereas they were 33.3%, 32.5% and 34.2%, respectively, in healthy control subjects. CT genotype carriers were more frequently found among gastric cancer patients than healthy controls (OR = 2.076; 95%CI: 1.282-3.360). Also, TT genotype carriers were more frequently found among gastric cancer patients (OR = 2.155; 95%CI: 1.340-3.466). Compared to the C allele of CD14/-260, the T allele was associated with an increased risk for gastric cancer (OR = 1.574; 95%CI: 1.121-2.045). Furthermore, the frequencies of CC, CT and TT in the CD14-651 C/T locus in gastric cancer patients were 64.4%, 29.3% and 6.2%, respectively, while they were 56.5%, 35.0% and 8.4%, respectively, in the healthy control subjects (P > 0.05). Data obtained using the luciferase reporter assay showed that the p260T homozygote was associated with greater CD14 promoter activity (P < 0.01).

CONCLUSION: CD14/-260 polymorphism is associated with gastric cancer risk in Highland Tibetans and affects CD14 promoter activity, thereby regulating CD14 expression.

Early-onset diffuse gastric cancer associated with a de novo large genomic deletion of CDH1 gene

A 41-year-old man with no familial history of gastric cancer was diagnosed as with intramucosal early gastric cancer. Two months after the first endoscopic submucosal dissection for signet-ring cell carcinoma (SRCC), the appearance of previously unrecognized multiple erosions of SRCC was noticed. Pathological examination after a total gastrectomy and Roux-en-Y reconstruction with D2 lymph node dissection were performed. Postoperative pathological examination revealed 90 and more lesions, which tempted the attending pathologist to refer to genetic tests for the predisposition though the patient had no familial history of gastric cancer. There were no mutations in all the exons of CDH1 with conventional DNA sequencing, but multiplex ligation-dependent probe amplification, and reverse transcription-polymerase chain reaction analyses disclosed a large genomic deletion (c.1566-?_1711+?del), leading to the mRNA with loss of the exon 11. Among family members, his son was found to be a carrier of this change, while his parents were negative for the familial CDH1 mutation, implying that this change is a de novo event in the proband. The present report is the first description of a de novo large genomic deletion of CDH1 gene associated with early-onset diffuse gastric cancer. When the clinician finds a relatively-young patient who has multiple SRCCs, CDH1 germline mutation should be considered, even for patients with no familial history.

Molecular approaches and modern clinical strategies for the management of Helicobacter pylori infection in Japan

Thirty years have passed since Warren and Marshall's discovery of Helicobacter pylori (H. pylori). Since then, not only peptic ulcer diseases and chronic gastritis but also non-cardia gastric cancers have been recognized as diseases originating from H. pylori infection. Several combination therapies consisting of multiple antibiotics have been developed as first- or second-line regimens to eradicate H. pylori infection. Our extensive experience in the field of anti-H. pylori medicine suggests that clinicians should consider a possible role for unidentified, invisible pathogens to elucidate the pathogenesis and improve the treatment of refractory diseases of unknown etiology.

Associations between the four toll-like receptor polymorphisms and the risk of gastric cancer: a meta-analysis

PURPOSE

The association between Toll-like receptor 2 (TLR2) -196 to -174del polymorphism and Toll-like receptor 4 (TLR4) polymorphisms (Asp299Gly, Thr399Ile, and 3725G>C) and gastric cancer risk are still conflicting. For better understanding of the effects of these four polymorphisms on gastric cancer risk, a meta-analysis was performed.

METHODS

An extensive search was performed to identify all case-control studies investigating such associations. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess the relationship.

RESULTS

A total of 21 studies (3,436 cases and 4,239 controls) were found to be eligible for meta-analysis. In the overall analysis, a significantly increased risk was observed in TLR4 Asp299Gly polymorphism (G allele vs. A allele: OR=1.84, 95%CI: 1.41, 2.39; GA vs. AA: OR=1.89, 95%CI: 1.43, 2.48; Recessive model: OR=1.90, 95%CI: 1.44, 2.49) and TLR4 Thr399Ile polymorphism (T allele vs. C allele: OR=1.97, 95%CI: 1.22, 3.18; TC vs. CC: OR=1.94, 95%CI: 1.19, 3.15; Recessive model: OR=1.98, 95%CI: 1.21, 3.21), whereas no associations were found in any genetic models of TLR2 -196 to -174del and TLR4 3725G>C polymorphisms. Similar results were found in the subgroup analyses by ethnicity. However, we detected that A allele carriers of the TLR4 Asp299Gly polymorphism might have an increase risk of gastric cancer in the Helicobacter pylori-positive population (G allele vs. A allele: OR=2.01, 95%CI: 1.22, 3.31).

CONCLUSION

The results of this meta-analysis indicate that the TLR4 Asp299Gly and Thr399Ile polymorphisms are risk factors for gastric cancer development.

Endoscopic diagnosis of gastric intestinal metaplasia: a prospective multicenter study

BACKGROUND

Intestinal metaplasia (IM) of the gastric mucosa has long attracted attention as a premalignant lesion involved in gastric carcinogenesis. However, endoscopic diagnosis of IM has remained unclear for a long time. In recent years, the methylene blue staining technique and narrow-band imaging (NBI) magnifying endoscopy have facilitated clinical diagnosis of IM, although these methods have some problems due to their complexity. Simple methods for diagnosis of IM using conventional endoscopy and the indigo carmine contrast (IC) method are necessary.

PATIENTS AND METHODS

This study was a multicenter, prospective, randomized, comparative study involving 10 facilities. The appearance of IM was examined using conventional and IC methods with an electronic endoscope.

RESULTS

Subjects included 163 patients, of whom 87 and 76 underwent conventional and IC methods, respectively. Sensitivity, specificity, and receiver operating characteristic/area under thecurve (ROC/AUC) of conventional and IC methods for the detection of IM in the gastric antrum showed that diagnostic performance of the conventional method was higher, but not significantly, than that of the IC method. Sensitivity, specificity and ROC/AUC of conventional and IC methods for the detection of IM in the gastric body showed that the IC method yielded better (but not significantly better) results than the conventional method.

CONCLUSION

The diagnostic performance of the conventional method did not significantly differ from that of the IC method. A villous appearance, whitish mucosa, and rough mucosal surface, as observed by both methods, and areae gastricae pattern, as observed by the IC method, were useful indicators for endoscopic diagnosis of IM.

[Molecular pathology of gastric cancer]

Gastric cancer is one of the most common cancers worldwide. In recent decades, major advancements in the understanding of the epidemiology, pathology and pathogenesis of gastric cancer have been witnessed. Infections with Helicobacter pylori or Epstein-Barr virus, dietary and lifestyle factors contribute to the risk of developing gastric cancer. With respect to pathogenesis at least three distinct types of gastric cancer exist, (1) proximal, (2) distal diffuse and (3) distal non-diffuse types. Genetic and epigenetic alterations are related to oncogene mutations and tumor suppressor gene inactivation. Canonical oncogenic pathways such as the WNT/β-catenin signaling pathway are de-regulated in gastric cancer. Hereditary and familial type gastric cancers are currently linked to CDH1 gene mutations and various genetic polymorphisms determining disease susceptibility. Molecular subtypes of gastric cancer have been identified which separate diffuse from intestinal type gastric cancer and are not entirely congruent with the histopathological phenotype according to Laurén but may influence chemosensitivity. Putative cancer stem cell markers of gastric cancer have been found (e.g. ADAM17, CD133, FZD7, LGR5) and correlate with patient prognosis. Thus, molecular phenotyping of gastric cancer is still in its infancy and the search for novel diagnostic, prognostic and predictive biomarkers continues.

CD44 variant 9 expression in primary early gastric cancer as a predictive marker for recurrence

BACKGROUND

Multiple early gastric cancers (EGCs) may develop in 6-14% of patients even after achieving curative endoscopic submucosal dissection (ESD); however, a useful biomarker for predicting recurrence is not available. The present study investigated whether the expression of CD44 variant 9 (CD44v9), a functional cancer stem cell marker, in the primary gastric cancer tissue represents an indicator of recurrence.

METHODS

Eighty-eight patients who underwent ESD for EGC from 2008 to 2010 were enrolled and monitored for recurrence for 3 years. The expression levels of CD44v9 in the tissue of initial EGCs were evaluated by immunohistochemistry, and the recurrence rate was compared between CD44v9-positive and CD44v9-negative groups. The mucin phenotype and expression of microRNA-21 (miR-21) and programmed cell death protein 4 (PDCD4) were also analysed.

RESULTS

The recurrence rate of EGC was significantly higher in the CD44v9-positive group than in the CD44v9-negative group (hazard ratio (HR), 21.8; 95% confidence interval (CI), 5.71-83.1). However, mucin phenotypes and the expression of miR-21 and PDCD4 did not predict recurrence after ESD. Meanwhile, grade of gastric atrophy was also identified as a significant marker of multiple recurrence (HR, 4.95; 95% CI, 1.30-18.8).

CONCLUSION

CD44 variant 9 expression represents a potential predictive marker for recurrence in EGC.

Reactive oxygen species-induced autophagic degradation of Helicobacter pylori CagA is specifically suppressed in cancer stem-like cells

Sustained expression of CagA, the type IV secretion effector of Helicobacter pylori, is closely associated with the development of gastric cancer. However, we observed that after translocation, CagA is degraded by autophagy and therefore short lived. Autophagy and CagA degradation are induced by the H. pylori vacuolating cytotoxin, VacA, which acted via decreasing intracellular glutathione (GSH) levels, causing reactive oxygen species (ROS) accumulation and Akt activation. Investigating this further, we found that CagA specifically accumulated in gastric cells expressing CD44, a cell-surface marker associated with cancer stem cells. The autophagic pathway in CD44-positive gastric cancer stem-like cells is suppressed because of their resistance to ROS, which is supported by increased intracellular GSH levels. These findings provide a molecular link between H. pylori and gastric carcinogenesis through the specific accumulation of CagA in gastric cancer stem-like cells.