Gastric cancer, Helicobacter pylori infection and other risk factors

Global, regional, and national burden of early-onset gastric cancer

OBJECTIVE

The burden of gastric cancer (GC) across different age groups needs updating. We determined the GC global, regional, and national burden profiles and changes in incidence for 3 sequential 5-year intervals from 2003 to 2017.

METHODS

The latest incidence and mortality estimates of GC from 185 countries and regions were extracted from the GLOBOCAN 2022 database. The 5-year interval age-standardised incidence rates (ASIRs) were evaluated using cancer registry data from volumes X-XII of the Cancer Incidence in Five Continents (CI5). Correlation analysis was used to evaluate the relationship between ASIR or the age-standardised mortality rate (ASMR) and the Human Development Index (HDI).

RESULTS

There was an estimated global 968,000 new GC cases and 660,000 deaths in 2022, with male predominance. GC ASIRs and ASMRs were 9.2 and 6.1 per 100,000 persons, respectively. East Asia had the highest burden, with 53.8% of cases and 48.2% of deaths among all geographic regions. There was a significant correlation between ASIR and HDI. Over three 5-year intervals from 2003 to 2017, the incidence of GC notably decreased in most countries but peaked at 2008-2012 in New Zealand, Turkey, and South Africa. Several countries in Europe, Oceania, and America suggest an increasingly concerning trend among younger individuals, especially females.

CONCLUSIONS

GC is a significant health issue, especially among males and in geographic regions with an HDI, such as eastern Asia. While the incidence of GC is decreasing in many countries due to prevention efforts and improved treatments, a rising trend persists among younger individuals. Comprehensive prevention strategies tailored to different age patterns are clearly needed.

Helicobacter pylori Secondary Antibiotic Resistance after One or More Eradication Failure: A Genotypic Stool Analysis Study

Helicobacter pylori (H. pylori) antibiotic resistance is the leading cause for unsuccessful eradication therapy. After one or more failures, the chance of encountering secondary antibiotic resistance increases. The aim of this study was to characterize genotypic secondary resistance in a cohort of southern Italian H. pylori patients with at least one previous failure. Such patients collected stool samples using a dedicated kit (THD fecal testTM), and bacterial DNA was extracted and amplified using RT-PCR. Resistance to clarithromycin, amoxicillin, metronidazole, levofloxacin, and tetracycline was assessed using a high-resolution melting curve. We enrolled 50 patients. A total of 72% of patients failed one previous antibiotic course, 16% failed two, 10% failed three, and 2% failed four. The rate of secondary antibiotic resistance was 16% for clarithromycin, 18% for metronidazole, 14% for amoxicillin, 14% for levofloxacin, and 2% for tetracycline. Among the eight clarithromycin-resistant patients, five (62.5%) previously received a clarithromycin-based regimen. The same rate was 33.3% (3/9) for metronidazole. The only tetracycline-resistant patient had received Pylera. In conclusion, our data seem to show that, even though secondary resistance is not very high, resistance to clarithromycin could be very likely related to previous exposure to this antibiotic.

A prospective study on Helicobacter pylori rapid urease test false negativity: is it time for its use in restricted situations?

BACKGROUND

Rapid urease test (RUT) is a diagnostic tool for Helicobacter pylori (H. pylori) diagnosis, based on the ability of the bacterium to produce urease. Despite it is considered simple, fast, and cheap, some conditions may cause false negativity. Therefore, the aim of this study was to compare RUT with currently recommended tests for H. pylori diagnosis.

METHODS

We enrolled consecutive patients who underwent upper endoscopy with histology, RUT, and urea breath test (UBT). Delta over baseline (DOB) >4% was considered positive for UBT. Diagnosis of infection was achieved when at least two tests were positive. The rate of false positivity of RUT was computed, and DOB value in RUT+ versus RUT- was compared by Mann-Whitney Test.

RESULTS

One hundred and sixteen consecutive patients with H. pylori infection were recruited. The male/female ratio was 35/81 and the mean age 45.2±13.1. Twenty-five patients (21.5%) were RUT-, despite being positive at both histology and UBT. On the other hand, in only two patients UBT and histology had discordant results. A full concordance of the three tests was observed in 89 patients (76.7%). DOB, additionally, was significantly higher in RUT+ patients (39.2±24.2%) than RUT- ones (26.3±18.5%; P=0.005).

CONCLUSIONS

RUT shows false negativity rate higher than 20%. Moreover, the RUT-negative patients showed a lower DOB at UBT, which is an indirect indicator of intragastric bacterial load. Therefore, it is presumable that H. pylori low amount may be a concurrent cause of false negativity. This study suggests that RUT-based H. pylori detection should be restricted to some specific conditions.

The Present and Future of Neoadjuvant and Adjuvant Therapy for Locally Advanced Gastric Cancer

Gastric cancer is a highly prevalent and lethal disease worldwide. Given the insidious nature of the presenting symptoms, patients are frequently diagnosed with advanced, unresectable disease. However, many patients will present with locally advanced gastric cancer (LAGC), which is often defined as the primary tumor extending beyond the muscularis propria (cT3-T4) or having nodal metastases (cN+) disease and without distant metastases (cM0). LAGC is typically treated with surgical resection and perioperative chemotherapy. The treatment of LAGC remains a challenge, given the heterogeneity of this disease, and the optimal multimodal treatment regimen may be different for different LAGC subtypes. However, many promising treatments are on the horizon based on knowledge of molecular subtypes and key biomarkers of LAGC, such as microsatellite instability, HER2, Claudin 18.2, FGFR2, and PD-L1. This review will expand upon the discussion of current standard neoadjuvant and adjuvant therapies for LAGC and explore the ongoing and future clinical trials for novel therapies, with information obtained from searches in PubMed and ClinicalTrials.gov.

Global Trend on Machine Learning in Helicobacter within One Decade: A Scientometric Study

Purpose

This study aims to create a science map, provide structural analysis, investigate evolution, and identify new trends in Helicobacter pylori (H. pylori) research articles.

Methods

All Helicobacter publications were gathered from the Web of Science (WoS) database from August 2010 to 2021. The data were required for bibliometric analysis. The bibliometric analysis was performed with Bibliometrix R Tool. Bibliometric data were analyzed using the Bibliometrix Biblioshiny R-package software.

Results

A total of 17,413 articles were reviewed and analyzed, with descriptive characteristics of the H. pylori literature included. In journals, 21,102 keywords plus and 20,490 author keywords were reported. These articles were also written by 56,106 different authors, with 262 being single-author articles. Most authors' abstracts, titles, and keywords included "Helicobacter-pylori." Since 2010, the total number of H. pylori-related publications has been decreasing. Gut, PLOS ONE, and Gastroenterology are the most influential H. pylori journals, according to source impact. China, the United States, and Japan are the countries with most affiliations and subjects. In addition, Seoul National University has published the most articles about H. pylori. According to the cloud word plot, the authors' most frequently used keywords are gastric cancer (GC), H. pylori, gastritis, eradication, and inflammation. "Helicobacter pylori" and "infection" have the steepest slopes in terms of the upward trend of words used in articles from 2010 to 2021. Subjects such as GC, intestinal metaplasia, epidemiology, peptic ulcer, eradication, and clarithromycin are included in the diagram's motor theme section, according to strategic diagrams. According to the thematic evolution map, topics such as Helicobacter pylori infection, B-cell lymphoma, CagA, Helicobacter pylori, and infection were largely discussed between 2010 and 2015. From 2016 to 2021, the top topics covered included Helicobacter pylori, H. pylori infection, and infection.

MiR-30e-3p inhibits gastric cancer development by negatively regulating THO complex 2 and PI3K/AKT/mTOR signaling

BACKGROUND

Gastric cancer (GC) is a common type of digestive cancer with high morbidity and mortality rates worldwide. Considerable effort has been expended in understanding the mechanism of GC development and metastasis. The current study therefore explores the involvement of microRNAs in the regulation of GC progression.

AIM

To explore the expression and function of miR-30e-3p in GC development.

METHODS

MiR-30e-3p was found to be downregulated in GC, with low levels thereof predicting poor outcomes among patients with GC. Functionally, we revealed that miR-30e-3p suppressed cell growth and metastatic behaviors of GC cells. Bioinformatics analysis predicted that THO complex 2 (THOC2) was a direct target of miR-30e-3p, and the interaction between miR-30e-3p and THOC2 was further validated by a luciferase reporter assay.

RESULTS

Our findings revealed that knockdown of THOC2 inhibited the growth and metastatic behaviors of GC cells. After investigating signaling pathways involved in miR-30e-3p regulation, we found that the miR-30e-3p/THOC2 axis regulated the PI3K/AKT/mTOR pathway in GC.

CONCLUSION

Our findings suggest the novel functional axis miR-30e-3p/THOC2 is involved in GC development and progression. The miR-30e-3p/THOC2 axis could be utilized to develop new therapies against GC.

Helicobacter pylori employs a general protein glycosylation system for the modification of outer membrane adhesins

Helicobacter pylori infection is associated with the development of several gastric diseases including gastric cancer. To reach a long-term colonization in the host stomach, H. pylori employs multiple outer membrane adhesins for binding to the gastric mucosa. However, due to the redundancy of adhesins that complement the adhesive function of bacteria, targeting each individual adhesin alone usually achieves nonideal outcomes for preventing bacterial adhesion. Here, we report that key adhesins AlpA/B and BabA/B in H. pylori are modified by glycans and display a two-step molecular weight upshift pattern from the cytoplasm to the inner membrane and from the inner membrane to the outer membrane. Nevertheless, this upshift pattern is missing when the expression of some enzymes related to lipopolysaccharide (LPS) biosynthesis, including the LPS O-antigen assembly and ligation enzymes WecA, Wzk, and WaaL, is disrupted, indicating that the underlying mechanisms and the involved enzymes for the adhesin glycosylation are partially shared with the LPS biosynthesis. Loss of the adhesin glycosylation not only reduces the protease resistance and the stability of the tested adhesins but also changes the adhesin-binding ability. In addition, mutations in the LPS biosynthesis cause a significant reduction in bacterial adhesion in the in vitro cell-line model. The current findings reveal that H. pylori employs a general protein glycosylation system related to LPS biosynthesis for adhesin modification and its biological significance. The enzymes required for adhesin glycosylation rather than the adhesins themselves are potentially better drug targets for preventing or treating H. pylori infection.

Incorporating Immunotherapy in the Management of Gastric Cancer: Molecular and Clinical Implications

Simple Summary

Gastric cancer is one of the most common malignant tumours worldwide, with the fifth and third highest morbidity and mortality, respectively, of all cancers. Survival is limited, as most of the patients are diagnosed at an advanced stage, and are not suitable for surgery with a curative intent. Chemotherapy has only modestly improved patients’ outcomes and is mainly given with a palliative intent. Immunotherapy has improved overall survival of patients with gastric cancer, and has thus become a new standard of care in clinic. In this review we discuss the strong molecular rationale for the administration of immunotherapy in this disease and analyse the clinical data supporting its use.

Abstract

Gastric cancer has a median survival of 11 months, and this poor prognosis has not improved over the last 30 years. Recent pre-clinical data suggest that there is high tumour-related neoantigen expression in gastric cancer cells, suggesting that a clinical strategy that enhances the host’s immune system against cancer cells may be a successful approach to improve clinical outcomes. Additionally, there has been an increasing amount of translational evidence highlighting the relevance of PD-L1 expression in gastric cancer cells, indicating that PD-1/PD-L1 inhibitors may be useful. Several molecular subgroups of gastric cancer have been identified to respond with excellent outcomes to immunotherapy, including microsatellite instable tumours, tumours bearing a high tumour mutational burden, and tumours related to a chronic EBV infection. In gastric cancer, immunotherapy has produced durable responses in chemo-refractory patients; however, most recently there has been a lot of enthusiasm as several large-scale clinical trials highlight the improved survival noted from the incorporation of immunotherapy in the first line setting for advanced gastric cancer. Our review aims to discuss current pre-clinical and clinical data supporting the innovative role of immunotherapy in gastric cancer.

Hedgehog Signaling: Linking Embryonic Lung Development and Asthmatic Airway Remodeling

The development of the embryonic lung demands complex endodermal-mesodermal interactions, which are regulated by a variety of signaling proteins. Hedgehog (Hh) signaling is vital for lung development. It plays a key regulatory role during several morphogenic mechanisms, such as cell growth, differentiation, migration, and persistence of cells. On the other hand, abnormal expression or loss of regulation of Hh signaling leads to airway asthmatic remodeling, which is characterized by cellular matrix modification in the respiratory system, goblet cell hyperplasia, deposition of collagen, epithelial cell apoptosis, proliferation, and activation of fibroblasts. Hh also targets some of the pathogens and seems to have a significant function in tissue repairment and immune-related disorders. Similarly, aberrant Hh signaling expression is critically associated with the etiology of a variety of other airway lung diseases, mainly, bronchial or tissue fibrosis, lung cancer, and pulmonary arterial hypertension, suggesting that controlled regulation of Hh signaling is crucial to retain healthy lung functioning. Moreover, shreds of evidence imply that the Hh signaling pathway links to lung organogenesis and asthmatic airway remodeling. Here, we compiled all up-to-date investigations linked with the role of Hh signaling in the development of lungs as well as the attribution of Hh signaling in impairment of lung expansion, airway remodeling, and immune response. In addition, we included all current investigational and therapeutic approaches to treat airway asthmatic remodeling and immune system pathway diseases.

The current and future incidence and mortality of gastric cancer in 185 countries, 2020-40: A population-based modelling study

Background

To examine global patterns of gastric cancer in 2020 and the projected burden in 2040.

Methods

Data on primary gastric cancer were extracted from the GLOBOCAN database for the year 2020. Age-standardized incidence and mortality rates were calculated by sex, country, world region and level of human development index (HDI) for 185 countries. The predicted burden of incidence and mortality in 2040 was calculated based on demographic projections.

Findings

In total, ∼1.1 million new cases and 770,000 deaths of gastric cancer were estimated in 2020. Incidence rates were on average 2-fold higher in males than females (15.8 and 7.0 per 100,000, respectively) with variation across countries. Highest incidence rates were observed in Eastern Asia for both males and females (32.5 and 13.2, respectively); males residing in Japan (48.1), Mongolia (47.2) and Korea (39.7) had the highest rates in the world. Incidence was lowest in Africa with incidence rates < 5 per 100,000. Highest mortality rates were observed in Eastern Asia for both males (21.1) and females (8.8). A lower share of deaths was observed in very high HDI countries compared to medium and low HDI countries. The annual burden of gastric cancer is predicted to increase to ∼1.8 million new cases and ∼1.3 million deaths by 2040.

Interpretation

These estimates of the global burden of gastric cancer pinpoint countries and regions of high incidence and mortality in need of cancer control initiatives. Primary prevention through eradication of H. pylori and behavioural changes such as reducing salt intake, smoking, obesity, and alcohol, remains key in stomach cancer control.

Funding

No direct funding was received. All authors had access to the included study data and all authors agreed with the final decision to submit for publication.

ARE THERE DIFFERENCES IN LAPAROSCOPIC GASTRECTOMY MORBIDITY AND MORTALITY BETWEEN YOUNG AND OLDER?

Background:

Due to the longer life expectancy and consequently an increase in the elderly population, a higher incidence of gastric cancer is expected in this population in the coming decades.

Aim:

To compare the results of laparoscopic GC surgical treatment between individuals aged<65 years (group I) and ≥ 65 years (group II), according to clinical, surgical, and histopathological characteristics.

Methods:

A observational retrospective study was performed by analyzing medical charts of patients with gastric cancer undergoing total or subtotal laparoscopic gastrectomy for curative purposes by a single oncologic surgery team.

Results:

Thirty-six patients were included in each group. Regarding the ASA classification, 31% of the patients in group I was ASA 1, compared to 3.1% in group II. The mean number of concomitant medications in group II was statistically superior to group I (5±4.21 x 1.42±3.08, p<0.001). Subtotal gastrectomy was the most performed procedure in both groups (69.4% and 63.9% in groups I and II, respectively) due to the high prevalence of distal tumors in both groups, 54.4% group I and 52.9% group II. According to Lauren's classification, group I presented a predominance of diffuse tumors (50%) and group II the intestinal type (61.8%). There was no difference between the two groups regarding the number of resected lymph nodes and lymph node metastases and the days of hospitalization and mortality.

Conclusion:

Laparoscopic gastrectomy showed to be a safe procedure, without a statistical difference in morbidity, mortality, and hospitalization time between both groups.

Helicobacter pylori co-infection with Epstein-Barr virus and the risk of developing gastric adenocarcinoma at an early age: Observational study infectious agents and cancer

Background

Gastric cancer (GC) is one of the leading causes of morbidity and mortality worldwide. The onset and progression of gastric cancer are attributed to numerous triggers, these triggers may be infection of the gastric epithelium by Helicobacter pylori (H. pylori), or by Epstein-Barr virus (EBV). Both agents can establish a lifelong persistent infection in the host, leading to chronic inflammation, which also contributes to cancer development. Objective: The objective of this study is to present the status of co-infection with H. pylori and EBV and the risk of developing adenocarcinoma at an early age in the population of Grand Casablanca.

Methods

In this study, 100 gastric tissue samples from patients with gastric cancer were examined for detection of H. pylori and EBV in tumor tissue using PCR techniques, and the clinical relevance was statistically analyzed.

Results

Results revealed an individual Epstein-Barr virus (EBV) infection observed in (40 %) of gastric carcinoma cases. Furthermore, the frequency of EBV infection was significantly different with intestinal and diffuse gastric cancer types [15 % vs. 85 %; <0.05]. The prevalence of individual H. pylori infections was 34 %, while the frequency of co-infection was 16 %. Moreover, no significant association was found between co-infection and sex, tumor grade, stage, and lymph node metastasis, but there was a significant association between co-infection and the age of GC patients.

Conclusion

Thus understanding the status of co-infection could clarify the process of gastric carcinogenesis, and application of this knowledge for clinical purposes could facilitate diagnosis, risk management, and prevention.

Determination of the frequency of H. pylori and EBV infections

Correlation between co-infection and age of gastric cancer patients

Evaluation of the clinicopathological features associated with the presence of infectious agents.

Helicobacter pylori GmhB enzyme involved in ADP-heptose biosynthesis pathway is essential for lipopolysaccharide biosynthesis and bacterial virulence

Helicobacter pylori infection is linked to serious gastric-related diseases including gastric cancer. However, current therapies for treating H. pylori infection are challenged by the increased antibiotic resistance of H. pylori. Therefore, it is in an urgent need to identify novel targets for drug development against H. pylori infection. In this study, HP0860 gene from H. pylori predicted to encode a D-glycero-D-manno-heptose-1,7-bisphosphate phosphatase (GmhB) involved in the synthesis of ADP-L-glycero-D-manno-heptose for the assembly of lipopolysaccharide (LPS) in the inner core region was cloned and characterized. We reported HP0860 protein is monomeric and functions as a phosphatase by converting D-glycero-D-manno-heptose-1,7-bisphosphate into D-glycero-D-manno-heptose-1-phosphate with a preference for the β-anomer over the α-anomer of sugar phosphate substrates. Subsequently, a HP0860 knockout mutant and its complementary mutant were constructed and their phenotypic properties were examined. HP0860 knockout mutant contained both mature and immature forms of LPS and could still induce significant IL-8 secretion after gastric AGS cell infection, suggesting other enzymatic activities in HP0860 knockout mutant might be able to partially compensate for the loss of HP0860 activity. In addition, HP0860 knockout mutant was much more sensitive to antibiotic novobiocin, had decreased adherence abilities, and caused less classic hummingbird phenotype on the infected AGS cells, indicating H. pylori lacking HP0860 is less virulent. Furthermore, the disruption of HP0860 gene altered the sorting of cargo proteins into outer membrane vesicles (OMVs). The above findings confirm the importance of HP0860 in LPS core biosynthesis and shed light on therapeutic intervention against H. pylori infection.

Gastric cancer prevention strategies: A global perspective

Gastric cancer (GC) is the fifth most common cancer worldwide, and mortality rates are still high. Primary preventive strategies, aimed to reduce risk factors and promote protective ones, will lead to a decrease in GC incidence. Helicobacter pylori infection is a well-established carcinogen for GC, and its eradication is recommended as the best strategy for the primary prevention. However, the role of other factors such as lifestyle, diet, and drug use is still under debate in GC carcinogenesis. Unfortunately, most patients with GC are diagnosed at late stages when treatment is often ineffective. Neoplastic transformation of the gastric mucosa is a multistep process, and appropriate diagnosis and management of preneoplastic conditions can reduce GC-related mortality. Several screening strategies in relation to GC incidence have been proposed in order to detect neoplastic lesions at early stages. The efficacy of screening strategies in reducing GC mortality needs to be confirmed. This review provides an overview of current international guidelines and recent literature on primary and secondary prevention strategies for GC.

Association of Symptoms with Eating Habits and Food Preferences in Chronic Gastritis Patients: A Cross-Sectional Study

Purpose

There is a lack of research on the relationship between symptoms and dietary factors of chronic gastritis (CG) patients, and the contribution of dietary management in relieving symptoms of CG patients has not attracted enough attention. This study aimed to identify the associations between different symptoms and dietary factors. Patients and Methods. All CG patients in this cross-sectional study were recruited from 3 hospitals in Beijing, China, from October 2015 to January 2016. Association Rule Mining analysis was performed to identify the correlations between gastrointestinal symptoms and dietary factors (including eating habits and food preferences), and subgroup analysis focused on gender differences.

Results

The majority of patients (58.17%) reported that their symptoms were related to dietary factors. About 53% reported that they had the habit of “eating too fast,” followed by “irregular mealtimes” (29.66%) and “eating leftover food” (28.14%). Sweets (27.57%), spicy foods (25.10%), and meat (24.33%) were the most popular among all participants. Stomachache and gastric distention were the most common symptoms and were both associated with irregular mealtimes, irregular meal sizes, eating out in restaurants, meats, barbecue, fried foods, sour foods, sweets, snacks, and salty foods (support >0.05 and lift >1.0). Their most strongly associated factors were irregular meal sizes, barbecues, and snacks (lift >1.2). In addition, irregular mealtimes, salty foods, and sweet foods may be important diet factors influencing the symptoms in CG patients (support >0.05 and lift >1.0), as they were associated with almost all dyspeptic symptoms in the whole group and subgroup analyses. Furthermore, alcohol, barbecue, and spicy foods were associated with almost all symptoms for males (support >0.05 and lift >1.0), but sweets were the only dietary factor associated with all symptoms for females (support >0.05 and lift >1.0).

Conclusion

This study has provided new data for the association of symptoms with eating habits and food preferences in CG patients. The role of individual daily management schemes, such as dietary or lifestyle programs, needs more attention.

HDAC3-dependent transcriptional repression of FOXA2 regulates FTO/m6A/MYC signaling to contribute to the development of gastric cancer

As one of the deadliest malignancies, gastric cancer (GC) is often accompanied by a low 5-year survival following initial diagnosis, which accounts for a substantial proportion of cancer-related deaths each year worldwide. Altered epigenetic modifications of cancer oncogenes and tumor suppressor genes emerge as novel mechanisms have been implicated the pathogenesis of GC. In the current study, we aim to elucidate whether histone deacetylase 3 (HDAC3) exerts oncogenic role in GC, and investigate the possible mechanism. Initially, we collected 64 paired cancerous and noncancerous tissues surgically resected from GC patients. Positive expression of HDAC3, FTO, and MYC in the tissues was measured using Immunohistochemistry. Meanwhile, GC cell line BGC-823/AGS was selected and treated with lentivirus vectors for alteration of HDAC3, FTO, or FOXA2 expressions, followed by detection on mRNA and protein levels of HDAC3, FOXA2, FTO, and MYC using reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot assays. The results demonstrated that the expressions of HDAC3, FTO and MYC were upregulated, while FOXA2 expression was downregulated in GC tissues and cells. After that, the cell viability, migration, and invasion of GC cells were assessed by CCK-8 and Transwell assays, revealing that HDAC3 accelerated GC cell viability, migration and invasion by degrading FOXA2. Subsequently, the binding relationship among HDAC3, FOXA2, FTO, and MYC was assessed by assays of immunoprecipitation, dual-luciferase reporter gene, and chromatin immunoprecipitation assay. Methylation of m6A mRNA in GC cells was detected via gene-specific m6A qPCR and dot-blot assays. The transcription factor FOXA2 was found to bind to the FTO gene promoter and decreased its expression, while FTO stabilized MYC mRNA by reducing m6A methylation of MYC in GC cells. In addition, HDAC3 was observed to maintain the FTO/m6A/MYC signaling and regulated GC progression, which was also supported by in vivo animal study data of GC cell tumorigenesis in nude mice. These key observations uncover the tumor-initiating activities of HDAC3 in GC through its regulation on FOXA2-mediated FTO/m6A/MYC axis, highlighting the potential of therapeutically targeting epigenetic modifications to combat GC.

MicroRNA-223-5p targets long non-coding RNA TP73 antisense RNA1 to promote the invasion of gastric cancer

Long non-coding RNA (lncRNA) TP73 antisense RNA 1 (TP73-AS1) has been characterized as an oncogenic lncRNA in GC. However, by analyzing The Cancer Genome Atlas (TCGA) dataset we observed the downregulation of TP73-AS1 in GC. In addition, TP73-AS1 is predicted to interact with microRNA-223-5p (miR-223-5p), which is also a critical player in cancer biology. This study was therefore carried out to investigate the roles of miR-223-5p and TP73-AS1 in gastric cancer (GC) and to explore the interactions between them. In this study, 68 GC patients were included as research subjects. Expression of miR-223-5p and TP73-AS1 was analyzed by RT-qPCR. Dual-luciferase assay and overexpression experiments were used to analyze gene interactions. Transwell assays were used to analyze cell invasion and migration. We found that miR-223-5p was upregulated and TP73-AS1 was downregulated in GC and they were inversely correlated. Altered miR-223-5p and TP73-AS1 expression predicted poor disease-specific survival. Dual-luciferase assay showed that miR-223-5p may bind TP73-AS1 and overexpression experiments showed that miR-223-5p overexpression downregulated TP73-AS1 in gastric cancer cells. Cell invasion and migration assays showed that miR-223-5p could promote the invasion and migration of gastric cancer cells, while TP73-AS1 could inhibit the invasion and migration of gastric cancer cells. In addition, miR-223-5p attenuated the effects of TP73-AS1 overexpression. Therefore, miR-223-5p may target TP73-AS1 to promote the invasion and migration of gastric cancer patients.

Sugar-Modified Analogs of Auranofin Are Potent Inhibitors of the Gastric Pathogen Helicobacter pylori

Helicobacter pylori (H. pylori) infection poses a worldwide public health crisis, as chronic infection is rampant and can lead to gastric ulcers, gastritis, and gastric cancer. Unfortunately, frontline therapies cause harmful side effects and are often ineffective due to antibiotic resistance. The FDA-approved drug auranofin is a gold complex with a Au(I) core coordinated with triethylphosphine and peracetylated thioglucose as the ligands. Auranofin is used for the treatment of rheumatoid arthritis and also displays potent activity against H. pylori. One of auranofin's modes of action involves cell death by disrupting cellular thiol-redox balance maintained by thioredoxin reductase (TrxR), but this disruption leads to unwanted side effects due to mammalian cell toxicity. Here, we developed and tested sugar-modified analogs of auranofin as potential antibiotics against H. pylori, with the rationale that modulating the sugar moiety would bias uptake by targeting bacterial cells and mitigating mammalian cell toxicity. Sugar-modified auranofin analogs displayed micromolar minimum inhibitory concentrations against H. pylori, maintained nanomolar inhibitory activity against the target enzyme TrxR, and caused reduced toxicity to mammalian cells. Taken together, our results suggest that structurally modifying the sugar component of auranofin has the potential to yield superior antibiotics for the treatment of H. pylori infection. Broadly, glyco-tailoring is an attractive approach for repurposing approved drugs.

Decursin inhibits tumor growth, migration, and invasion in gastric cancer by down-regulating CXCR7 expression

CXC chemokine receptor 7 (CXCR7) is highly expressed in various type of cancers and promotes cancer progression and metastasis. However, the biological role and regulation of CXCR7 in gastric cancer remains unclear, and little is known about compounds that modulate CXCR7. Here, we investigated the role of CXCR7 in gastric tumorigenesis, and the effects of decursin, which is derived from Angelica gigas Nakai, on CXCR7. Our results showed that CXCR7 significantly promoted growth of gastric cancer cells and increased migration and invasion, which was mediated by the STAT3/c-Myc pathway. We also confirmed that decursin had an antitumor effect through down-regulating the expression of CXCR7 in gastric cancer. Furthermore, apoptotic cell death was induced through the reduction of anti-apoptotic factors such as Bcl-2 in vitro and in vivo. Our findings show that CXCR7 in gastric cancer promotes cancer progression through the STAT3/c-Myc pathway and that decursin is a natural compound that may target CXCR7 in gastric cancer treatment.

Polymorphisms in IL-10 and TGF-β gene promoter are associated with lower risk to gastric cancer in a Mexican population

BACKGROUND

Helicobacter pylori infection is recognized as the main risk factor for gastric cancer (GC), the fifth most common neoplasia worldwide. H. pylori interacts with the immune system, disrupting the cytokine network and inducing chronic inflammation. This work aimed to evaluate the association between single nucleotide polymorphisms (SNPs) in selected cytokine gene promoters and GC.

METHODS

The study included 359 subjects, 125 GC patients, 109 intestinal metaplasia (IM) patients and 125 asymptomatic controls. DNA was extracted from white blood cells and nine SNPs in cytokine gene promoters were genotyped using predesigned 5'-endonulease assays. The association of the SNPs with IM and GC was evaluated using multinomial regression models.

RESULTS

Both genotypes, TC (OR = 0.51, 95% CI = 0.27-0.98) and TT (OR = 0.42, 95% CI = 0.20-0.91) in the locus - 509 of the TGF-β promoter were significantly associated with GC. The TT genotype in the locus - 819 of the IL-10 promoter was also significantly associated with GC (OR = 0.37, 95% CI = 0.17-0.81). No significant association was found with SNPs IL-4 -590 T/C (rs1800629), IL-6 -573G/C (rs1800796), IL-10 -592C/A (rs1800872), IL-10 -1082A/G (rs1800896), and, IFN-γ -1615C/T (rs2069705).

CONCLUSIONS

SNPs in TGFβ (- 509 C/T, rs1800469) and IL-10 (- 819 C/T, rs1800871) promoters were associated with a lower risk for GC in a Mexican population.

Bivariate Spatio-Temporal Shared Component Modeling: Mapping of Relative Death Risk due to Colorectal and Stomach Cancers in Iran Provinces

BACKGROUND

Gastrointestinal cancers make for nearly half fatal cancers with colorectal and stomach cancers' being listed among the ten most common in Iran. This research aims to determine the spatial pattern and temporal trend of death risk due to colorectal and stomach cancers among provinces of Iran and estimate the effect of shared and specific components as surrogates of risk factors for the aforementioned cancers on changes of death due to the cancers over time and place.

METHODS

In this ecological study, the data regarding death causes in colorectal and stomach cancers during 2006-2011 were obtained from the death registration system of the Iranian Ministry of Health. The estimation of relative risk (RR) of death due to the target cancers was performed applying Bayesian spatiotemporal shared component (SC) model in OpenBUGS software.

RESULTS

North-Western provinces ranked first regarding stomach cancer RR of death (RR >1.75). Furthermore, some North-Western and central provinces had the highest RR of death due to colorectal cancer (RR >1.5). The SC surrogating the risk factor shared between both cancers had the most effect in Northern, North-Western and western provinces, and the least effect in Southern and South-Eastern ones.

CONCLUSIONS

North and North-West of Iran found to be the high-risk area for death due to both stomach and colorectal cancers and South-East and South provinces shown to have the lowest RR. The obtained results can be illuminating to health resource allocation to the health policymakers.

Long-term gastric cancer risk in male smokers with atrophic corpus gastritis

OBJECTIVES

The aim of this study was to evaluate long-term gastric cancer risk in male smokers with and without atrophic gastritis.

MATERIALS AND METHODS

A total of 22,346 elderly male smokers participated in the Helsinki Gastritis Study between the years 1989 and 1993. Serum pepsinogen I (PGI) was measured for the men, and 2,132 men with low PGI (<25 µg/L; a marker of atrophic corpus gastritis) were invited to undergo gastroscopy because of increased gastric cancer risk. Endoscopy was performed to 1,327 men, who were followed up for a median of 13.6 years and a maximum of 25.3 years thereafter. In addition, the gastric cancer risk of men with low PGI was compared to that of the men with normal PGI and to the general Finnish male population of the same age.

RESULTS

Thirty-five cases of gastric cancer were diagnosed in men with gastroscopy during the follow-up. The incidence rate was 1.94 per 1000 patient years. The men with a history of gastric surgery (n = 180) due to a benign cause had even higher gastric cancer incidence (3.2 per 1000 patient-years). Gastric cancer risk was highest in men with marked intestinal metaplasia in primary biopsies. Compared to the general Finnish male population of the same age, the cancer risk was 1.13 times higher in male smokers with normal serum PGI, and 2.43 times higher in men with low serum PGI.

CONCLUSION

In male smokers, atrophic gastritis and intestinal metaplasia increase the risk of gastric cancer.

Beyond Tissue Stiffness and Bioadhesivity: Advanced Biomaterials to Model Tumor Microenvironments and Drug Resistance

Resistance to chemotherapy and pathway-targeted therapies poses a major problem in cancer research. While the fields of tumor biology and experimental therapeutics have already benefited from ex vivo preclinical tissue models, these models have yet to address the reasons for malignant transformations and the emergence of chemoresistance. With the increasing number of ex vivo models poised to incorporate physiological biophysical properties, along with the advent of genomic sequencing information, there are now unprecedented opportunities to better understand tumorigenesis and to design therapeutic approaches to overcome resistance. Here we discuss that new preclinical ex vivo models should consider - in addition to common biophysical parameters such as matrix stiffness and bioadhesivity - a more comprehensive milieu of tissue signaling, nuclear mechanics, immune response, and the gut microbiome.

The Hedgehog Signaling Pathway Emerges as a Pathogenic Target

The Hedgehog (Hh) signaling pathway plays an essential role in the growth, development, and homeostatis of many tissues in vertebrates and invertebrates. Much of what is known about Hh signaling is in the context of embryonic development and tumor formation. However, a growing body of evidence is emerging indicating that Hh signaling is also involved in postnatal processes such as tissue repair and adult immune responses. To that extent, Hh signaling has also been shown to be a target for some pathogens that presumably utilize the pathway to control the local infected environment. In this review, we discuss what is currently known regarding pathogenic interactions with Hh signaling and speculate on the reasons for this pathway being a target. We also hope to shed light on the possibility of using small molecule modulators of Hh signaling as effective therapies for a wider range of human diseases beyond their current use in a limited number of cancers.

Expression of podocalyxin-like protein is an independent prognostic biomarker in resected esophageal and gastric adenocarcinoma

BACKGROUND

Podocalyxin-like protein (PODXL) is a cell surface transmembrane glycoprotein, the expression of which has been associated with poor prognosis in a range of malignancies. The aim of this study was to investigate the impact of PODXL expression on survival in esophageal and gastric adenocarcinoma.

METHODS

The study cohort consists of a consecutive series of 174 patients with esophageal (including the gastroesophageal junction) or gastric adenocarcinoma, surgically treated between 2006 and 2010 and not subjected to neoadjuvant treatment. Immunohistochemical expression of PODXL was assessed in tissue microarrays with cores from primary tumors, lymph node metastases, intestinal metaplasia and adjacent normal epithelium. Survival analyses were performed on patients with no distant metastases and no macroscopic residual tumor.

RESULTS

In the majority of cases, expression of PODXL was significantly higher in cancer cells compared to normal epithelial cells and was significantly associated with lymph node metastases and high grade tumors. In esophageal adenocarcinoma, Kaplan-Meier analyses revealed that patients with PODXL negative tumors had a superior time to recurrence (TTR) and overall survival (OS) compared to patients with PODXL positive tumors. In gastric adenocarcinoma, patients with PODXL negative tumors had a superior TTR and a trend towards an improved OS. In esophageal and gastric adenocarcinoma combined, the prognostic significance of PODXL expression on TTR was confirmed in unadjusted Cox regression analysis (HR = 5.36, 95 % CI 1.68-17.06, p = 0.005) and remained significant in the adjusted model (HR = 3.39, 95 % CI 1.01-11.35, p = 0.048). Moreover, the impact of PODXL expression on OS was also confirmed in unadjusted analysis (HR = 2.52, 95 % CI 1.31-4.85, p = 0.006) and remained significant in the adjusted model (HR = 2.03, 95 % CI 1.04-3.98, p = 0.039).

CONCLUSIONS

In esophageal and gastric adenocarcinoma, PODXL expression is an independent prognostic biomarker for reduced time to recurrence and poor overall survival. This is the first report on the prognostic role of PODXL in esophageal adenocarcinoma and validates recent findings in gastric cancer.

Expression of IFITM1 as a prognostic biomarker in resected gastric and esophageal adenocarcinoma

BACKGROUND

There is an increasing amount of reports on IFITM1 (interferon-inducible transmembrane protein 1) in various malignancies. The aim of this study was to examine the expression of IFITM1 and its prognostic significance in gastroesophageal adenocarcinoma.

METHODS

Tissue samples were obtained from a consecutive cohort of 174 patients surgically treated between 2006 and 2010 for gastroesophageal (gastric, gastroesophageal junction and esophageal) adenocarcinoma, not subjected to neoadjuvant therapy. Expression of IFITM1 was examined using immunohistochemistry on tissue microarrays of primary tumors and paired samples of adjacent normal epithelium, intestinal metaplasia and lymph node metastases.

RESULTS

Expression of IFITM1 was significantly elevated in primary tumors and lymph node metastases compared to adjacent normal epithelium and intestinal metaplasia, regardless of tumor location. Overexpression of IFITM1 was associated with M0-disease (no distant metastases). In gastric cancer IFITM1 expression was significantly associated with improved TTR (time to recurrence) in Kaplan-Meier analysis and Cox regression, both in the unadjusted analysis (HR 0.33, 95 % CI 0.12-0.88) and in the adjusted analysis (HR 0.32, 95 % CI 0.12-0.87) but there was no significant impact on OS (overall survival). In esophageal adenocarcinoma expression of IFITM1 had no impact on TTR or OS in Kaplan-Meier-analyses, but in the adjusted Cox regression IFITM1 expression had a negative impact on both TTR (HR 3.05, 95 % CI 1.09-8.53) and OS (HR 2.71, 95 % CI 1.11-6.67).

CONCLUSIONS

IFITM1 was overexpressed in gastroesophageal adenocarcinoma and associated with M0-disease. In gastric cancer IFITM1 expression had a positive impact on TTR but in esophageal cancer it seemed to have an adverse impact on survival. The reason for the diverging prognostic impact of IFITM1 in esophageal and gastric cancer is unclear and warrants further studies.

HNF4α is a therapeutic target that links AMPK to WNT signalling in early-stage gastric cancer

BACKGROUND

Worldwide, gastric cancer (GC) is the fourth most common malignancy and the most common cancer in East Asia. Development of targeted therapies for this disease has focused on a few known oncogenes but has had limited effects.

OBJECTIVE

To determine oncogenic mechanisms and novel therapeutic targets specific for GC by identifying commonly dysregulated genes from the tumours of both Asian-Pacific and Caucasian patients.

METHODS

We generated transcriptomic profiles of 22 Caucasian GC tumours and their matched non-cancerous samples and performed an integrative analysis across different GC gene expression datasets. We examined the inhibition of commonly overexpressed oncogenes and their constituent signalling pathways by RNAi and/or pharmacological inhibition.

RESULTS

Hepatocyte nuclear factor-4α (HNF4α) upregulation was a key signalling event in gastric tumours from both Caucasian and Asian patients, and HNF4α antagonism was antineoplastic. Perturbation experiments in GC tumour cell lines and xenograft models further demonstrated that HNF4α is downregulated by AMPKα signalling and the AMPK agonist metformin; blockade of HNF4α activity resulted in cyclin downregulation, cell cycle arrest and tumour growth inhibition. HNF4α also regulated WNT signalling through its target gene WNT5A, a potential prognostic marker of diffuse type gastric tumours.

CONCLUSIONS

Our results indicate that HNF4α is a targetable oncoprotein in GC, is regulated by AMPK signalling through AMPKα and resides upstream of WNT signalling. HNF4α may regulate 'metabolic switch' characteristic of a general malignant phenotype and its target WNT5A has potential prognostic values. The AMPKα-HNF4α-WNT5A signalling cascade represents a potentially targetable pathway for drug development.

Withaferin A Inhibits Helicobacter pylori-induced Production of IL-1β in Dendritic Cells by Regulating NF-κB and NLRP3 Inflammasome Activation

Helicobacter pylori infection is associated with chronic gastritis, peptic ulcer, and gastric cancer. There is evidence that IL-1β is associated with the development of gastric cancer. Therefore, downregulation of H. pylori-mediated IL-1β production may be a way to prevent gastric cancer. Withaferin A (WA), a withanolide purified from Withania somnifera, is known to exert anti-inflammatory and anti-tumor effects. In the present study, we explored the inhibitory activity of WA on H. pylori-induced production of IL-1β in murine bone marrow-derived dendritic cells (BMDCs) and the underlying cellular mechanism. Co-treatment with WA decreased IL-1β production by H. pylori in BMDCs in a dose-dependent manner. H. pylori-induced gene expression of IL-1β and NLRP3 (NOD-like receptor family, pyrin domain containing 3) were also suppressed by WA treatment. Moreover, IκB-α phosphorylation by H. pylori infection was suppressed by WA in BMDCs. Western blot analysis revealed that H. pylori induced cleavage of caspase-1 and IL-1β, as well as increased procaspase-1 and pro IL-1β protein levels, and that both were suppressed by co-treatment with WA. Finally, we determined whether WA can directly inhibit ac tivation of the NLRP3 inflammasome. NLRP3 activators induced IL-1β secretion in LPS-primed macrophages, which was inhibited by WA in a dose-dependent manner, whereas IL-6 production was not affected by WA. Moreover, cleavage of IL-1β and caspase-1 by NLRP3 activators was also dose-dependently inhibited by WA. These findings suggest that WA can inhibit IL-1β production by H. pylori in dendritic cells and can be used as a new preventive and therapeutic agent for gastric cancer.

Role of Helicobacter pylori infection in gastric carcinogenesis: Current knowledge and future directions

Helicobacter pylori (H. pylori) plays a role in the pathogenesis of gastric cancer. The outcome of the infection depends on environmental factors and bacterial and host characteristics. Gastric carcinogenesis is a multistep process that is reversible in the early phase of mucosal damage, but the exact point of no return has not been identified. Therefore, two main therapeutic strategies could reduce gastric cancer incidence: (1) eradication of the already present infection; and (2) immunization (prior to or during the course of the infection). The success of a gastric cancer prevention strategy depends on timing because the prevention strategy must be introduced before the point of no return in gastric carcinogenesis. Although the exact point of no return has not been identified, infection should be eradicated before severe atrophy of the gastric mucosa develops. Eradication therapy rates remain suboptimal due to increasing H. pylori resistance to antibiotics and patient noncompliance. Vaccination against H. pylori would reduce the cost of eradication therapies and lower gastric cancer incidence. A vaccine against H. pylori is still a research challenge. An effective vaccine should have an adequate route of delivery, appropriate bacterial antigens and effective and safe adjuvants. Future research should focus on the development of rescue eradication therapy protocols until an efficacious vaccine against the bacterium becomes available.

Case–control study of Epstein–Barr virus and Helicobacter pylori serology in Latin American patients with gastric disease

Background:

Chronic tissue damage induced by Helicobacter pylori (HP)-driven inflammation is considered the main risk of gastric carcinoma (GC). Epstein–Barr virus (EBV) infection has also been associated with GC. In this study, we aim to address the role of EBV in inflammatory GC precursor lesions and its added risk to HP infection.

Methods:

Antibodies against EBV, HP and the bacterial virulence factor CagA were measured in sera from 525 Mexican and Paraguayan patients with gastric disease. Gastric samples were characterised according to the updated Sydney classification and associations were estimated between antibody responses and severity of both tissue damage and inflammation.

Results:

We found significant associations (odd ratios and trends) between EBV and HP copositivity and premalignant lesions and intestinal-type GC. The EBV and HP coinfection was also significantly associated with increased infiltration of immune cells. No association was found between EBV and the less inflammation-driven diffuse-type GC.

Conclusions:

Our study suggests that EBV co-participates with HP to induce severe inflammation, increasing the risk of progression to intestinal-type GC.

Structural and biochemical characterization of GTP cyclohydrolase II from Helicobacter pylori reveals its redox dependent catalytic activity

GTP cyclohydrolase II (GCHII), catalyzes the conversion of GTP to 2,5-diamino-6-β-ribosyl-4(3H)-pyrimidinone-5'-phosphate and has been shown to be essential for pathogens. Here we describe the biochemical, kinetic and structural characterization of GCHII from Helicobacter pylori (hGCHII). The crystal structure of hGCHII, unlike other GCHII structures, revealed that cysteines at the active site existed in oxidized state forming two disulfide bonds and lacked Zn(2+) that was shown to be indispensable for catalytic activity in other species. However, incubation of hGCHII with hydrogen peroxide, an oxidizing agent, followed by PAR-assay showed that Zn(2+) was intrinsically present, indicating that all cysteines at the catalytic site remained in reduced state. Moreover, site directed mutagenesis of catalytic site cysteines revealed that only three, out of four cysteines were essential for hGCHII activity. These results, though, indicated that hGCHII crystallized in oxidized form, the expulsion of Zn(2+) upon oxidation of catalytic cysteines revealed its ability to act in response to the redox environment. Exploring further, incubation of hGCHII with reversible thiol modifying agent S-methyl-methane-thiosulfonate resulted in loss of GCHII activity due to oxidation of its cysteine residues as revealed by mass spectrometry studies. However, addition of reducing agent DTT partially restored the hGCHII catalytic activity. Taken together, these results demonstrate that hGCHII can regulate its catalytic activity depending on the redox environment, a function hitherto unknown for GCHII.

Effect of Helicobacter pylori infection on gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is a common chronic disease of the digestive system. In recent years, due to the better understanding of Helicobacter pylori (H. pylori) and the wide clinical application of proton pump inhibitors, the rate of H. pylori infection is declining, while the incidence of GERD is increasing. This phenomenon suggests a possible relationship between H. pylori infection and the incidence of GERD. The pathogenesis of GERD is related to the dysfunction of the protective esophageal barrier, esophageal motility, gastric acidity and gastric emptying, and H. pylori infection may affect these factors to exert an impact on the incidence of GERD.

Epidemiology of Helicobacter pylori infection

Medline and PubMed databases were searched on epidemiology of Helicobacter pylori for the period of April 2013-March 2014. Several studies have shown that the prevalence of H. pylori is still high in most countries. In north European and North American populations, about one-third of adults are still infected, whereas in south and east Europe, South America, and Asia, the prevalence of H. pylori is often higher than 50%. H. pylori remains highly prevalent in immigrants coming from countries with high prevalence of H. pylori. However, the lower prevalence of infection in the younger generations suggests a further decline of H. pylori prevalence in the coming decades. Low socioeconomic conditions in childhood are confirmed to be the most important risk factors for H. pylori infection. Although the way the infection is transmitted is still unclear, interpersonal transmission appears to be the main route. Finally, H. pylori recurrence after successful eradication can still occur, but seems to be an infrequent event.

Brazilian consensus in gastric cancer: guidelines for gastric cancer in Brazil

BACKGROUND

In Brazil, gastric cancer is the fourth most common malignancy among men and sixth among women. The cause is multivariate and the risks are well known. It has prognosis and treatment defined by the location and staging of the tumor and number of lymph nodes resected and involved.

AIM

The Brazilian Consensus on Gastric Cancer promoted by ABCG was designed with the intention to issue guidelines that can guide medical professionals to care for patients with this disease.

METHODS

Were summarized and answered 43 questions reflecting consensus or not on diagnosis and treatment that may be used as guidance for its multidisciplinary approach. The method involved three steps. Initially, 56 digestive surgeons and related medical specialties met to formulate the questions that were sent to participants for answers on scientific evidence and personal experience. Summaries were presented, discussed and voted in plenary in two other meetings. They covered 53 questions involving: diagnosis and staging (six questions); surgical treatment (35 questions); chemotherapy and radiotherapy (seven questions) and anatomopathology, immunohistochemistry and perspective (five questions). It was considered consensus agreement on more than 70% of the votes in each item.

RESULTS

All the answers were presented and voted upon, and in 42 there was consensus.

CONCLUSION

It could be developed consensus on most issues that come with the care of patients with gastric cancer and they can be transformed in guidelines.

Eradication therapy in Helicobacter pylori-negative, gastric low-grade mucosa-associated lymphoid tissue lymphoma patients: a systematic review

AIM

To assess the remission rate of gastric low-grade B-cell mucosa-associated lymphoid tissue lymphoma after an eradication therapy in Helicobacter pylori-negative patients.

METHODS

We performed a systematic review with pooled analysis of published studies. Data were analyzed according to: (1) number of H. pylori-negative patients treated with only eradication therapy; (2) number of patients in whom the complete lymphoma remission was achieved; and (3) the method used to exclude H. pylori infection.

RESULTS

Overall, 11 studies with 110 patients met the inclusion criteria for this pooled analysis. H. pylori infection was excluded in all studies with at least 3 different diagnostic tests. Eradication therapy achieved a complete lymphoma regression in 17 (15.5%; 95% confidence interval, 8.7-22.2) patients.

CONCLUSIONS

Eradication therapy is successful in a small but distinct subgroup of H. pylori-negative patients with low-grade mucosa-associated lymphoid tissue lymphoma. On the basis of the generally indolent behavior of this neoplasia, before resorting to aggressive, costly, and potentially more toxic oncologic therapies, it would seem reasonable to attempt eradication therapy in all patients, irrespective of their H. pylori status.

Diversity of Helicobacter pylori genotypes in Iranian patients with different gastroduodenal disorders

AIM

To investigate the diversity of Helicobacter pylori (H. pylori) genotypes and correlations with disease outcomes in an Iranian population with different gastroduodenal disorders.

METHODS

Isolates of H. pylori from patients with different gastroduodenal disorders were analyzed after culture and identification by phenotypic and genotypic methods. Genomic DNA was extracted with the QIAamp DNA mini kit (Qiagen, Germany). After DNA extraction, genotyping was done for cagA, vacA (s and m regions), iceA (iceA1 , iceA2 ) and babA with specific primers for each allele using polymerase chain reaction (PCR). All patients' pathologic and clinical data and their relation with known genotypes were analyzed by using SPSS version 19.0 software. χ² test and Fisher's exact test were used to assess relationships between categorical variables. The level of statistical significance was set at P < 0.05.

RESULTS

A total of 71 isolates from 177 patients with different gastroduodenal disorders were obtained. Based on analysis of the cagA gene (positive or negative), vacA s-region (s1 or s2), vacA m-region (m1 or m2), iceA allelic type (iceA1 and iceA2 ) and babA gene (positive or negative), twenty different genotypic combinations were recognized. The prevalence of cagA, vacA s1 , vacA s2 , vacA m1 , vacA m2 , iceA1 , iceA2 , iceA1+iceA2 and babA were 62%, 78.9%, 19.7%, 21.1%, 78.9%, 15.5%, 22.5%, 40.8% and 95.8%, respectively. Interestingly, evaluation of PCR results for cagA in 6 patients showed simultaneous existence of cagA variants according to their size diversities that proposed mixed infection in these patients. The most prevalent genotype in cagA-positive isolates was cagA⁺/vacAs1m2 /iceA1 +A2 /babA+ and in cagA-negative isolates was cagA⁻/vacAs1m2 /iceA-/babA+. There were no relationships between the studied genes and histopathological findings (H. pylori density, neutrophil activity, lymphoid aggregation in lamina propria and glandular atrophy). The strains which carry cagA, vacAs1/m1 , iceA2 and babA genes showed significant associations with severe active chronic gastritis (P = 0.011, 0.025, 0.020 and 0.031, respectively). The vacAs1 genotype had significant correlation with the presence of the cagA gene (P = 0.013). Also, babA genotype showed associations with cagA (P = 0.024). In the combined genotypes, only cagA⁺/vacAs1m1 /iceA2 /babA+ genotype showed correlation with severe active chronic gastritis (P = 0.025).

CONCLUSION

This genotyping panel can be a useful tool for detection of virulent H. pylori isolates and can provide valuable guidance for prediction of the clinical outcomes.

Helicobacter pylori promotes invasion and metastasis of gastric cancer cells through activation of AP-1 and up-regulation of CACUL1

Infection with Helicobacter pylori is important in the development and progression of gastric cancer. However, the mechanisms that regulate this activation in gastric tumors remain elusive. CACUL1 has been cloned and identified as a novel gene that is expressed in many types of cancer and is involved in cell cycle regulation and tumor growth. The current study aimed to examine the expression of CACUL1 in gastric cancer samples and analyze its correlation with H. pylori infection. We found that CACUL1 was highly expressed in gastric cancer tissues and negatively correlated with gastric cancer differentiation and TNM stage. In addition, CACUL1 expression was high in H. pylori-infected tissues compared with H. pylori non-infected tissue. We found that H. pylori could up-regulate CACUL1 expression through activating protein 1. The up-regulation of CACUL1 expression could promote matrix metalloproteinase 9 and Slug expression to increase invasion and metastasis of tumor cells. These results suggested that H. pylori-triggered CACUL1 production occurred in an activating protein 1-dependent manner and regulated matrix metalloproteinase 9 and Slug expression to affect the invasion and metastasis of tumor cells. Therefore, CACUL1 is a potential therapeutic target for the treatment of aggressive gastric cancer.

Preferences for the "screen and treat" strategy of Helicobacter pylori to prevent gastric cancer in healthy Korean populations

BACKGROUND

Helicobacter pylori (HP) eradication may reduce the risk of gastric cancer, and professional guidelines recommend eradication based on patients' preference. However, little data exist regarding individual's preference for HP eradication to prevent gastric cancer. We explored healthy Korean populations' preference for HP "screen and treat" strategy and its associated factors.

METHODS

We conducted a cross-sectional survey with 604 healthy adults expected to undergo screening esophagogastroduodenoscopy during routine health checkups. Survey packages-including a decision aid about "screen and treat" strategy for the HP eradication-were sent to the eligible people 1-3 weeks before the health checkup. Within the survey package, we first assessed people's knowledge and experience with HP test and treatment, provided the decision aid, and evaluated participants' preference for screening and treatment for HP to prevent gastric cancer.

RESULTS

With the provision of the decision aid, most participants (73.7%) opted for the "screen and treat" strategy. Having family member(s) with gastric cancer (adjusted odds ratio (aOR) = 2.28; 95% confidence interval (CI), 1.16-4.47), previous treatment history of HP (aOR = 2.70; 95% CI, 1.38-5.29), and higher baseline knowledge (aOR = 1.16; 95% CI, 1.07-1.26) were significantly associated with accepting the strategy. Most participants (71.4%)-and even individuals who did not choose "screen and treat" strategy-agreed with the provision with the decision aid.

CONCLUSIONS

Individuals preferred to take the "screen and treat" strategy for the prevention of gastric cancer. Further intervention study is warranted to see if implementation of decisional support would improve decision quality and patient outcomes.

Opium: an emerging risk factor for gastric adenocarcinoma

Opium use has been associated with higher risk of cancers of the esophagus, bladder, larynx, and lung; however, no previous study has examined its association with gastric cancer. There is also little information on the associations between hookah (water pipe) smoking or the chewing of tobacco products and the risk of gastric cancer. In a case-control study in Golestan Province of Iran, we enrolled 309 cases of gastric adenocarcinoma (118 noncardia, 161 cardia and 30 mixed-location adenocarcinomas) and 613 matched controls. Detailed information on long-term use of opium, tobacco products and other covariates were collected using structured and validated lifestyle and food frequency questionnaires. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were obtained using conditional logistic regression models. Opium use was associated with an increased risk of gastric adenocarcinoma, with an adjusted OR (95% CI) of 3.1 (1.9-5.1), and this increased risk was apparent for both anatomic subsites (cardia and noncardia). There was a dose-response effect, and individuals with the highest cumulative opium use had the strongest association (OR: 4.5; 95% CI: 2.3-8.5). We did not find a statistically significant association between the use of any of the tobacco products and risk of gastric adenocarcinoma, overall or by anatomic subsite. We showed, for the first time, an association between opium use and gastric adenocarcinoma. Given that opium use is a traditional practice in many parts of the world, these results are of public health significance.

Helicobacter pylori eradication and reflux disease onset: Did gastric acid get "crazy"?

Gastroesophageal reflux disease (GORD) is highly prevalent in the general population. In the last decade, a potential relationship between Helicobacter pylori (H. pylori) eradication and GORD onset has been claimed. The main putative mechanism is the gastric acid hypersecretion that develops after bacterial cure in those patients with corpus-predominant gastritis. We performed a critical reappraisal of the intricate pathogenesis and clinical data available in this field. Oesophagitis onset after H. pylori eradication in duodenal ulcer patients has been ascribed to a gastric acid hypersecretion, which could develop following body gastritis healing. However, the absence of an acid hypersecretive status in these patients is documented by both pathophysiology and clinical studies. Indeed, duodenal ulcer recurrence is virtually abolished following H. pylori eradication. In addition, intra-oesophageal pH recording studies failed to demonstrated increased acid reflux following bacterial eradication. Moreover, oesophageal manometric studies suggest that H. pylori eradication would reduce - rather than favor - acid reflux into the oesophagus. Finally, data of clinical studies would suggest that H. pylori eradication is not significantly associated with either reflux symptoms or erosive oesophagitis onset, some data suggesting also an advantage in curing the infection when oesophagitis is already present. Therefore, the legend of “crazy acid” remains - as all the others - a fascinating, but imaginary tale.

Standard triple and sequential therapies for Helicobacter pylori eradication: an update

H. pylori infection remains a worldwide spread disease with a definite morbidity and mortality. Unfortunately, no current therapy regimen is able to cure the infection in all treated patients. The efficacy of the widely recommended triple therapies is decreasing, and a novel 10-day sequential therapy has been proposed. Data of 3 previous meta-analyses showed a significantly higher eradication rate following the sequential as compared to the 7-10 days triple therapies. The sequential therapy achieved significantly better results than triple therapies in children, elderly patients, non-ulcer dyspepsia patients, and in those infected with resistant strains towards either clarithromycin or metronidazole. We identified further 10 randomized trials. By pooling data, H. pylori infection was cured in 2,454 (86%; 95% CI: 84.7-87.3) out of 2,853 patients with the sequential therapy and in 2,320 (75.3%; 95% CI: 73.8-76.9) out of 3,079 patients treated with standard triple therapies (p<0.001), corresponding to a number to treat (NNT) of 9. The comparison between the 10-day sequential regimen and 14-day triple therapies deserves further investigations.

Helicobacter pylori therapy: Present and future

Helicobacter pylori (H. pylori) plays a crucial role in the pathogenesis of chronic active gastritis, peptic ulcer and gastric mucosa-associated lymphoid tissue-lymphoma, and is also involved in carcinogenesis of the stomach. H. pylori treatment still remains a challenge for physicians, since no current first-line therapy is able to cure the infection in all treated patients. Several factors may help in the eradication of therapy failure. We reviewed both bacterial and host factors involved in therapeutic management of the H. pylori infection. In addition, we evaluated data on the most successful therapy regimens - sequential and concomitant therapies - currently available for H. pylori eradication.

Follow-up of intestinal metaplasia in the stomach: When, how and why

Gastric cancer remains the second most frequent cause of cancer-related mortality in the world. Screening programs in some Asian countries are impractical in the majority of other countries worldwide. Therefore, follow-up of precancerous lesions is advisable for secondary gastric cancer prevention. Intestinal metaplasia (IM) is recognized as a precancerous lesion for gastric cancer, increasing the risk by 6-fold. IM is highly prevalent in the general population, being detected in nearly 1 of every 4 patients undergoing upper endoscopy. The IM prevalence rate is significantly higher in patients with Helicobacter pylori (H. pylori) infection, in first-degree relatives of gastric cancer patients, in smokers and it increases with patient age. IM is the “breaking point” in the gastric carcinogenesis cascade and does not appear to regress following H. pylori eradication, although the cure of infection may slow its progression. Gastric cancer risk is higher in patients with incomplete-type IM, in those with both antral and gastric body involvement, and the risk significantly increases with IM extension over 20% of the gastric mucosa. Scheduled endoscopic control could be cost-effective in IM patients, depending on the yearly incidence of gastric cancer in IM patients, the stage of gastric cancer at diagnosis discovered at surveillance, and the cost of endoscopy. As a pragmatic behavior, yearly endoscopic control would appear justified in all IM patients with at least one of these conditions: (1) IM extension > 20%; (2) the presence of incomplete type IM; (3) first-degree relative of gastric cancer patients; and (4) smokers. In the remaining IM patients, a less intensive (2-3 years) could be proposed.