Helicobacter pylori in gastric carcinogenesis

Helicobacter pylori Seroprevalence and Its Associations with Sociodemographic Characteristics, Environmental Factors, and Gastrointestinal Complaints: A Cross-Sectional Study in the Adult Population of Kaunas City, Lithuania

Background and Objectives: Helicobacter pylori, classified as a Group I carcinogen, is the main risk factor for gastric cancer, one of the leading causes of cancer mortality globally. Lithuania reports one of the highest gastric cancer rates in Europe, yet recent large-scale epidemiological data on H. pylori prevalence are lacking. This study aimed to assess the current seroprevalence of H. pylori in Lithuanian adults and its associations with sociodemographic, environmental factors, and dyspeptic symptoms. Materials and Methods: A cross-sectional study was conducted between 2020 and 2023 at the Lithuanian University of Health Sciences in Kaunas city. Randomly selected adults aged 25-69 years underwent venous blood sampling for H. pylori IgG antibody testing (Serion ELISA) and completed a questionnaire on demographic-environmental factors and dyspeptic symptoms in the past 30 days. Subjects previously treated for H. pylori were excluded from seroprevalence analysis. Seroprevalence was compared across age groups using χ2 and Z-tests with Bonferroni correction. Multivariable logistic regression identified factors associated with H. pylori seropositivity. The selected level of statistical significance was p < 0.05. Results: A total of 1046 adults (mean age 47.2 years, SD = 11.5; 50% males) participated in the study. The overall age-standardized H. pylori seroprevalence was 63.1% (95% CI 60.4-66.7). Seropositivity increased with age, peaking at 80.3% in males aged 55-69. Higher seroprevalence was observed among those with basic education and those lacking access to municipal or heated water during childhood. Regression analysis revealed that male sex, aging, and lower education were significantly associated with H. pylori seropositivity. No significant link was found between H. pylori seroprevalence and gastrointestinal complaints. Conclusions: H. pylori seroprevalence remains high in Lithuanian adults, highlighting the need for ongoing surveillance and consideration of screening strategies. H. pylori infection was linked to sociodemographic and environmental factors but not dyspeptic complaints.

Application of an organoid-based model to explore Helicobacter pylori-human gastric epithelium interaction in vitro

Helicobacter pylori infection causes histopathologic changes in gastric epithelial cells, resulting in conditions such as gastritis, gastric ulcers, and ultimately, gastric cancer. To date, various experimental models, including cell lines and animal studies, have been employed to investigate these pathological processes. However, each model presents its limitations. This study compared the re-cultured three-dimensional organoids from infected single cells, apical-out, and two-dimensional (2D) organoids models to better understand the mechanisms underlying the epithelial changes caused by H. pylori infection in the human stomach. Thus, we analyzed the epithelial cell responses, inflammatory mediator expressions, apical-junctional complex alterations, and H. pylori infection interactions in these organoid models. Moreover, we revealed that the high accessibility and experimental efficiency of the apical-out and 2D models enable easier manipulation and faster analysis of H. pylori infection compared to the single-cell infection model. These results indicate the potential of various organoid models in H. pylori infection studies to provide essential data that help in understanding the mechanisms of epithelial changes and in developing new therapeutic strategies for gastric pathology.

Non-coding RNAs as potential mediators of resistance to lung cancer immunotherapy and chemotherapy

Lung cancer is a common cause of cancer-related death globally. The majority of lung cancer patients initially benefit from chemotherapy and immunotherapy. However, as the treatment cycle progresses and the disease evolves, the emergence of acquired resistance leads to treatment failure. Many researches have shown that non-coding RNAs (ncRNAs) not only influence lung cancer progression but also act as potential mediators of immunotherapy and chemotherapy resistance in lung cancer, mediating drug resistance by regulating multiple targets and pathways. In addition, the regulation of immune response by ncRNAs is dualistic, forming a microenvironment for inhibits/promotes immune escape through changes in the expression of immune checkpoints. The aim of this review is to understand the effects of ncRNAs on the occurrence and development of lung cancer, focusing on the role of ncRNAs in regulating drug resistance of lung cancer.

Comparative Analysis of Oral Prevotella intermedia, Tannerella forsythia, Streptococcus sanguinis, and Streptococcus mutans in Patients with Esophageal Squamous Cell Carcinoma and Healthy Controls in Mthatha, South Africa

The microbiome plays a crucial role in cancer development, influencing fundamental processes such as cell proliferation, apoptosis, immune system regulation, and host metabolism. Recent studies have highlighted a possible relationship between esophageal cancer and the oral microbiota, making oral microflora a possible risk factor. The bacteria Prevotella intermedia, Tannerella forsythia, Streptococcus sanguinis, and Streptococcus mutans, implicated in various oral pathologies, were of interest in this study, which was initiated to examine their potential role in the etiology of esophageal squamous cell carcinoma (ESCC). To achieve this, a case-control design was used, with whole saliva samples collected from 24 healthy controls and 24 patients with esophageal squamous cell carcinoma. DNA was then extracted, and real-time PCR was performed to quantify the presence of the targeted bacteria in both groups. The results showed that all the bacteria studied were present in the saliva of both patients with ESCC and healthy controls. However, expression levels were significantly higher in patients with ESCC. Specifically, a marked increase in the presence of P. intermedia, T. forsythia, S. sanguinis, and S. mutans was observed in the patients with cancer compared to the healthy controls. In short, this study highlights a significant imbalance in the microbial flora, with an increased abundance of selected bacteria in patients with ESCC. The monitoring of these bacteria could thus be exploited to track patients who are at risk. Their integration into diagnostic and therapeutic strategies would offer new prospects for the early diagnosis and improved prognosis of patients at risk of ESCC.

Immunoinformatic strategy for developing multi-epitope subunit vaccine against Helicobacter pylori

Helicobacter pylori is a gram-negative bacterium that persistently infects the human stomach, leading to peptic ulcers, gastritis, and an increased risk of gastric cancer. The extremophilic characteristics of this bacterium make it resistant to current drug treatments, and there are no licensed vaccines available against H. pylori. Computational approaches offer a viable alternative for designing antigenic, stable, and safe vaccines to control infections caused by this pathogen. In this study, we employed an immunoinformatic strategy to design a set of candidate multi-epitope subunit vaccines by combining the most potent B and T cell epitopes from three targeted antigenic proteins (BabA, CagA, and VacA). Out of the 12 hypothetical vaccines generated, two (HP_VaX_V1 and HP_VaX_V2) were found to be strongly immunogenic, non-allergenic, and structurally stable. The proposed vaccine candidates were evaluated based on population coverage, molecular docking, immune simulations, codon adaptation, secondary mRNA structure, and in silico cloning. The vaccine candidates exhibited antigenic scores of 1.19 and 1.01, with 93.5% and 90.4% of the most rama-favored regions, respectively. HP_VaX_V1 and HP_VaX_V2 exhibited the strongest binding affinity towards TLR-7 and TLR-8, as determined by molecular docking simulations (ΔG = -20.3 and -20.9, respectively). Afterward, multi-scale normal mode analysis simulation revealed the structural flexibility and stability of vaccine candidates. Additionally, immune simulations showed elevated levels of cell-mediated immunity, while repeated exposure simulations indicated rapid antigen clearance. Finally, in silico cloning was performed using the expression vector pET28a (+) with optimized restriction sites to develop a viable strategy for large-scale production of the chosen vaccine constructs. These analyses suggest that the proposed vaccines may elicit potent immune responses against H. pylori, but laboratory validation is needed to verify their safety and immunogenicity.

Immune cell changes in Helicobacter pylori infection-induced glandular epithelial cell damage of the gastric mucosa

OBJECTIVE

The purpose of this study was to investigate the relationship between Helicobacter pylori (H. pylori) infection-induced changes in gastric mucosal immune cells and glandular epithelial cell damage and the histopathological characteristics of these changes.

METHODS

We performed a detailed histomorphometry and immunohistochemical analysis of a total of 1635 H. pylori-infected gastric mucosal specimens.

RESULTS

Stage-wise features were as follows: Early stage of infection: H. pylori was colonized in the mucous layer, and very few neutrophils were visible in the layer. Gastric surface epithelial cell infection stage: H. pylori specifically and selectively adhered to the cytoplasm of the surface mucous cells, with the presence of a small number of neutrophils, eosinophils, and lymphocytes infiltration, which is termed early immune response. Compensatory mucous neck cell hyperplasia stage: proliferation of stem cells in the deep gastric pit and infiltration of a large number of lymphocytes in the superficial layer of lamina propria were observed, which is termed immune cell mobilization counterinsurgency. Lamina propria lesion stage: excessive upward migration of the proliferative area. Infiltration of a large number of lymphocytes, plasma cells, monocytes, macrophages, and other immune cells was observed in the whole layer of the gastric mucosa, which is termed automatic replication of immune cells. Abnormal proliferative transformation stage: presence of intranuclear milky globular body cells or signet-ring cell-like heterotypic cells at the junction of the gastric pit and the gastric gland, with proliferation of large numbers of immune cells and vacuolar degeneration of immune cells, which is termed the proliferation and degeneration of immune cells. Intraepithelial neoplasia stage: clonal hyperplasia of epithelial cells and immunosuppression.

CONCLUSION

For controlling the occurrence and development of gastric cancer and effective immune intervention, it is essential to grasp the relationship between H. pylori infection-induced changes in gastric mucosal immune cells and glandular epithelial cell damage and its histopathological characteristics.

Insights into Helicobacter pylori macrolide resistance: a comprehensive systematic review and meta-analysis

Background

Helicobacter pylori infection is a primary global health concern. However, the widespread use of antibiotics, particularly macrolides such as clarithromycin, has increased resistance among H. pylori strains. This study aimed to investigate the prevalence of macrolide resistance in H. pylori in different world regions.

Methods

This systematic literature search was performed using the appropriate search syntax after searching PubMed, Embase, Web of Science, and Scopus databases between May 2015 and December 2023. Statistical analysis was performed using Pooled and random effects model in R and the metafor package.

Results

A total of 7,768 articles were retrieved. After a thorough evaluation, 155 studies (by 178 reports) were finally eligible for inclusion in this systematic review and meta-analysis. According to the results, the majority of studies (178 reports from 43 countries) assessed clarithromycin susceptibility, with a pooled prevalence of 33.3% and high heterogeneity between studies (I 2 = 98.57%, p < 0.001). The rate of erythromycin resistance was moderate (22.8%, 10 reports), while azithromycin resistance was 34.4% (4 reports). Subgroup analysis revealed significant differences in the prevalence of resistance based on geographic location, continent, and year of publication. Clarithromycin resistance increased from 29.1% (2015-2019) to 36.5% (2020-2023).

Conclusion

This study highlights the critical challenges of macrolide resistance in treating H. pylori infection. The high prevalence and geographic variation underscore the need for tailored treatment strategies based on regional resistance patterns. Furthermore, continuously monitoring resistance trends and investigating contributing factors are essential to optimize treatment.

Systematic review registration

https://www.crd.york.ac.uk/prospero; CRD42024557749.

miR-1286, a Tumor Suppressor of Gastric Cancer, Serves as a Promising Biomarker for Screening Gastric Cancer from Gastritis

Gastric cancer (GC) is one of the crucial causes of cancer-associated death worldwide. This study aimed to investigate the biological function of miR-1286 in GC progression in vitro, evaluate the clinical value of serum miR-1286 to screen GC patients and explore its relationship with helicobacter pylori (HP) infection and peritoneal metastasis in GC patients. Expression of miR-1286 was measured by RT-qPCR. Cell Counting Kit-8 assay was utilized for measuring GC cell proliferation ability. The migration and invasion abilities of GC cells were measured using Transwell assays. Serum samples were obtained from 108 GC patients, 62 gastritis cases and 62 healthy volunteers. The diagnostic performance of miR-1286 was assessed using ROC analysis, and the predictive value of miR-1286 for peritoneal metastasis onset was analyzed using logistic regression analysis. miR-1286 played as a tumor suppressor in GC progression by inhibiting GC cell proliferation, migration and invasion. In GC patients, significantly decreased miR-1286 was observed compared to gastritis and healthy controls, and had considerable diagnostic accuracy to distinguish GC from the controls. A significant association was found between miR-1286 expression and HP infection, peritoneal metastasis and TNM stage. Moreover, miR-1286 was lowly expressed in GC patients with peritoneal metastasis, and independently predicted the occurrence of peritoneal metastasis in GC. miR-1286 acts as a tumor suppressor and a biomarker in GC, and is closely associated with HP infection and peritoneal metastasis onset. The methods to regulate miR-1286 may be novel strategies to improve the treatment of GC.

Hypoxia exacerbates the malignant transformation of gastric epithelial cells induced by long-term H. pylori infection

Helicobacter pylori is a microaerophilic Gram-negative bacterium that resides in the human stomach and is classified as a class I carcinogen for gastric cancer. Numerous studies have demonstrated that H. pylori infection plays a role in regulating the function of host cells, thereby contributing to the malignant transformation of these cells. However, H. pylori infection is a chronic process, and short-term cellular experiments may not provide a comprehensive understanding of the in vivo situation, especially when considering the lower oxygen levels in the human stomach. In this study, we aimed to investigate the mechanisms underlying gastric cell dysfunction after prolonged exposure to H. pylori under hypoxic conditions. We conducted a co-culture experiment using the gastric cell line GES-1 and H. pylori for 30 generations under intermittent hypoxic conditions. By closely monitoring cell proliferation, migration, invasion, autophagy, and apoptosis, we revealed that sustained H. pylori stimulation under hypoxic conditions significantly influences the function of GES-1 cells. This stimulation induces epithelial-mesenchymal transition and contributes to the propensity for malignant transformation of gastric cells. To confirm the in vitro results, we conducted an experiment involving Mongolian gerbils infected with H. pylori for 85 weeks. All the results strongly suggest that the Nod1 receptor signaling pathway plays a crucial role in H. pylori-related apoptosis and autophagy. In summary, continuous stimulation by H. pylori affects the functioning of gastric cells through the Nod1 receptor signaling pathway, increasing the likelihood of cell carcinogenesis. The presence of hypoxic conditions further exacerbates this process.IMPORTANCEDeciphering the collaborative effects of Helicobacter pylori infection on gastric epithelial cell function is key to unraveling the development mechanisms of gastric cancer. Prior research has solely examined the outcomes of short-term H. pylori stimulation on gastric epithelial cells under aerobic conditions, neglecting the bacterium's nature as a microaerophilic organism that leads to cancer following prolonged stomach colonization. This study mimics a more genuine in vivo infection scenario by repeatedly exposing gastric epithelial cells to H. pylori under hypoxic conditions for up to 30 generations. The results show that chronic exposure to H. pylori in hypoxia substantially increases cell migration, invasion, and epithelial-mesenchymal transition, while suppressing autophagy and apoptosis. This highlights the significance of hypoxic conditions in intensifying the carcinogenic impact of H. pylori infection. By accurately replicating the in vivo gastric environment, this study enhances our comprehension of H. pylori's pathogenic mechanisms in gastric cancer.

Oral Hygiene With Neutral Electrolyzed Water and Systemic Therapy Increases Gastric Helicobacter pylori Eradication and Reduces Recurrence

OBJECTIVES

Helicobacter pylori gastric infection strongly correlates with gastric diseases such as chronic gastritis, functional dyspepsia, and complications such as peptic ulcers and gastric cancer. In developing countries, systemic therapies are not usually successful due to elevated antibiotic resistance. Additionally, oral H. pylori infection and periodontal disease correlate with gastric treatment failures. This study aimed to explore the effect of an integral therapy, comprising oral hygiene and concomitant systemic treatment, to increase the eradication of gastric infection and recurrences.

MATERIALS AND METHODS

A prospective, randomized, four-arm, parallel-group, open-label clinical trial was conducted to investigate the efficacy of integral therapy to eradicate gastric H. pylori infection and avoid recurrences in double-positive (real-time PCR oral and gastric infection) patients. Oral hygiene involved mouthwash with neutral electrolyzed water (NEW), with or without periodontal treatment. One hundred patients were equally distributed into four groups: NS, NS-PT, NEW, and NEW-PT. All patients had concomitant systemic therapy and additionally, the following oral treatments: mouthwash with normal saline (NS), periodontal treatment and mouthwash with normal saline (NS-PT), mouthwash with NEW (NEW), and periodontal treatment and mouthwash with NEW (NEW-PT). Gastric and oral infection and symptoms were evaluated one and four months after treatments.

RESULTS

Integral therapy with NEW-PT increased gastric eradication rates compared with NS or NS-PT (84%-96% vs. 20%-56%; p < 0.001). Even more, a protective effect of 81.2% (RR = 0.1877; 95% CI: 0.0658-0.5355; p = 0.0018) against recurrences and 76.6% (RR = 0.2439; 95% CI: 0.1380-0.4310; p < 0.001) against treatment failure (eradication of infection and associated symptoms) was observed in patients from the NEW and NEW-PT groups.

CONCLUSIONS

Implementation of oral hygiene and systemic treatment can increase the eradication of gastric infection, associated symptoms, and recurrences. NEW is recommended as an antiseptic mouthwash due to its efficacy and short- and long-term safety.

The prevalence and risk factors of Helicobacter pylori infection and cagA virulence gene carriage in adults in the Navajo Nation

Background

American Indian and Alaska Native people in the United States experience high rates of stomach cancer. Helicobacter pylori infection is a significant risk factor for stomach cancer, and H. pylori strains that carry the cagA gene are linked to greater gastrointestinal disease severity. Yet, little is known about H. pylori and cagA infections in American Indian and Alaska Native people, particularly at the tribal level. We assessed the prevalence and risk factors of H. pylori infection and cagA gene carriage in tribal members from the Navajo Nation.

Materials and Methods

We conducted a cross-sectional study with adults from the Navajo Nation. Stool samples collected from participants were analyzed with droplet digital PCR for H. pylori 16S ribosomal and cagA virulence genes. Self-administered health and food questionnaires were mailed to participants to collect information on sociodemographic, health, lifestyle, and environmental risk factors for H. pylori infection. Logistic regression assessed the association between risk factors and H. pylori infection and cagA gene carriage.

Results

Among 99 adults, the median age was 45 (age range: 18 to 79 years), and 73.7% were female. About 56.6% (95% CI: 46.2-66.5) of participants were infected with H. pylori. Of H. pylori-infected participants, 78.6% (95% CI: 65.6-88.4) were cagA-gene positive. No significant associations of relevant risk factors with H. pylori and cagA-gene positive infections were noted.

Conclusions

In a community-based study population, a substantial proportion of adult tribal members had H. pylori and cagA-gene positive infections. Given these high proportions, culturally appropriate prevention strategies and interventions addressing H. pylori infections present an avenue for additional research and stomach cancer prevention in the Navajo Nation.

A prominent role of LncRNA H19 in H. pylori CagA induced DNA damage response and cell malignancy

Helicobacter pylori (H. pylori), together with its CagA, has been implicated in causing DNA damage, cell cycle arrest, apoptosis, and the development of gastric cancer. Although lncRNA H19 is abundantly expressed in gastric cancer and functions as a pro-oncogene, it remains unclear whether lncRNA H19 contributes to the oncogenic process of H. pylori CagA. This study investigates the role of H19 in the DNA damage response and malignancy induced by H. pylori. It was observed that cells infected with CagA+ H. pylori strain (GZ7/cagA) showed significantly higher H19 expression, resulting in increased γH2A.X and p-ATM expression and decreased p53 and Rad51 expression. Faster cell migration and invasion was also observed, which was reversed by H19 knockdown in H. pylori. YWHAZ was identified as an H19 target protein, and its expression was increased in H19 knockdown cells. GZ7/cagA infection responded to the increased YWHAZ expression induced by H19 knockdown. In addition, H19 knockdown stimulated cells to enter the G2-phase and attenuated the effect of GZ7/cagA infection on the cellular S-phase barrier. The results suggest that H. pylori CagA can upregulate H19 expression, participate in the DNA damage response and promote cell migration and invasion, and possibly affect cell cycle arrest via regulation of YWHAZ.

Gastric Cancer Survivorship: Multidisciplinary Management, Best Practices and Opportunities

PURPOSE

Gastric cancer is the 5th most common malignancy worldwide. As early detection increases and treatments for gastric cancer improve, the number of gastric cancer survivors grows.

METHODS

Here, we review the diagnosis and management of gastric cancer and discuss important considerations for gastric cancer survivorship including cancer surveillance, weight loss, malnutrition, fatigue, specific complications related to surgery and radiation, quality of life in gastric cancer survivorship, health behavior, and models of survivorship.

RESULTS

Multimodality therapy with chemotherapy and surgery can result in chronic toxicities in multiple organ systems. This emphasizes the need for a multidisciplinary survivorship care model including cancer surveillance, management of chronic toxicities, and optimization of modifiable risk factors with long-term involvement of appropriate providers.

CONCLUSION

Adequately caring for gastric cancer survivors requires a coordinated, multidisciplinary approach.

Detection of H. pylori outer membrane protein (HopQ) biomarker using electrochemical impedimetric immunosensor with polypyrrole nanotubes and carbon nanotubes nanocomposite on screen-printed carbon electrode

Helicobacter pylori (H. pylori) is classified as a class I carcinogen that colonizes the human gastrointestinal (GI) tract. The detection at low concentrations is crucial in combatting H. pylori. HopQ protein is located on H. pylori's outer membrane and is expressed at an early stage of contamination, which signifies it as an ideal biomarker. In this study, we presented the development of an electrochemical impedimetric immunosensor for the ultra-sensitive detection of HopQ at low concentrations. The sensor employed polypyrrole nanotubes (PPy-NTs) and carboxylated multi-walled carbon nanotubes (MWCNT-COOH) nanocomposite. PPy-NTs were chosen for their excellent conductivity, biocompatibility, and redox capabilities, simplifying sample preparation by eliminating the need to add redox probes upon measurement. MWCNT-COOH provided covalent binding sites for HopQ antibodies (HopQ-Ab) on the biosensor surface. Characterization of the biosensor was performed using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), contact angle measurements, and electrochemical impedance spectroscopy (EIS), complemented by numerical semiempirical quantum calculations. The results demonstrated a dynamic linear range of 5 pg/mL to 1.063 ng/mL and an excellent selectivity, with the possibility of excluding interference using EIS data, specifically charge transfer resistance and double-layer capacitance as multivariants for the calibration curve. Using two EIS components, the limit of detection is calculated to be 2.06 pg/mL. The biosensor was tested with a spiked drinking water sample and showed a signal recovery of 105.5% when detecting 300 pg/mL of HopQ. This novel H. pylori biosensor offers reliable, simple, portable, and rapid screening of the bacteria.

Co-administration of amoxicillin-loaded chitosan nanoparticles and inulin: A novel strategy for mitigating antibiotic resistance and preserving microbiota balance in Helicobacter pylori treatment

Helicobacter pylori (H. pylori) is a causative agent of various gastrointestinal diseases and eradication mainly relies on antibiotic treatment, with (AMX) being a key component. However, rising antibiotic resistance in H. pylori necessitates the use of antibiotics combination therapy, often disrupting gut microbiota equilibrium leading to further health complications. This study investigates a novel strategy utilizing AMX-loaded chitosan nanoparticles (AMX-CS NPs), co-administered with prebiotic inulin to counteract H. pylori infection while preserving microbiota health. Following microbroth dilution method, AMX displayed efficacy against H. pylori, with a MIC50 of 48.34 ± 3.3 ng/mL, albeit with a detrimental impact on Lactobacillus casei (L. casei). The co-administration of inulin (500 μg/mL) with AMX restored L. casei viability while retaining the lethal effect on H. pylori. Encapsulation of AMX in CS-NPs via ionic gelation method, resulted in particles of 157.8 ± 3.85 nm in size and an entrapment efficiency (EE) of 86.44 ± 2.19 %. Moreover, AMX-CS NPs showed a sustained drug release pattern over 72 h with no detectable toxicity on human dermal fibroblasts cell lines. Encapsulation of AMX into CS NPs also reduced its MIC50 against H. pylori, while its co-administration with inulin maintained L. casei viability. Interestingly, treatment with AMX-CS NPs also reduced the expression of the efflux pump gene hefA in H. pylori. This dual treatment strategy offers a promising approach for more selective antimicrobial treatment, minimizing disruption to healthy microbial communities while effectively addressing pathogenic threats.

Helicobacter pylori Eradication Can Reverse Rho GTPase Expression in Gastric Carcinogenesis

Background/Aims

Altered DNA methylation is a key mechanism of epigenetic modification in gastric cancer (GC). This study aimed to evaluate the changes in epigenetic and genetic expression of multiple Rho GTPases in Helicobacter pylori-related gastric carcinogenesis by comparing H. pylori-positive GCs and negative controls.

Methods

The messenger RNA expression and methylation of Rho GTPases (RhoA, Rac1, DOCK180, ELMO1, and CDC42) were evaluated in H. pylori-negative (control) human gastric tissues and H. pylori-positive GCs by using real-time reverse transcription-polymerase chain reaction and the quantitative MethyLight assay, respectively. Changes in expression and methylation levels of the genes were also compared between H. pylori-eradicated and -persistent GCs at 1-year follow-up.

Results

In GCs, the methylation and expression levels of DOCK180 and ELMO1 were higher than in controls, while RhoA and Rac1 had lower levels than controls. CDC42 had the same expression pattern as DOCK180 and ELMO1 without DNA methylation. Although methylation levels of DOCK180 and ELMO1 had no difference between H. pylori-eradicated and -persistent GCs at the index endoscopic resection, those of H. pylori-persistent GCs increased and H. pylori-eradicated GCs decreased for 1 year. The expression levels of DOCK180, ELMO1, and CDC42 in H. pylori-persistent GCs were higher than those in H. pylori-eradicated GCs over 1 year, unlike those of RhoA and Rac1. The methylation levels at index and the degrees of change over time of RhoA and Rac1 had no difference between H. pylori-persistent and -eradicated GCs.

Conclusions

Epigenetic alterations of DOCK180 and ELMO1 are involved in H. pylori-related gastric carcinogenesis. This epigenetic field could be improved by H. pylori eradication.

Impact of gut microbiome in the development and treatment of pancreatic cancer: Newer insights

The gut microbiome plays an important role in the variation of pharmacologic response. This aspect is especially important in the era of precision medicine, where understanding how and to what extent the gut microbiome interacts with drugs and their actions will be key to individualizing therapy. The impact of the composition of the gut microbiome on the efficacy of newer cancer therapies such as immune checkpoint inhibitors and chimeric antigen receptor T-cell treatment has become an active area of research. Pancreatic adenocarcinoma (PAC) has a poor prognosis even in those with potentially resectable disease, and treatment options are very limited. Newer studies have concluded that there is a synergistic effect for immunotherapy in combination with cytotoxic drugs, in the treatment of PAC. A variety of commensal microbiota can affect the efficacy of conventional chemotherapy and immunotherapy by modulating the tumor microenvironment in the treatment of PAC. This review will provide newer insights on the impact that alterations made in the gut microbial system have in the development and treatment of PAC.

Novel Sensitive Electrochemical Immunosensor Development for the Selective Detection of HopQ H. pylori Bacteria Biomarker

Helicobacter pylori (H. pylori) is a highly contagious pathogenic bacterium that can cause gastrointestinal ulcers and may gradually lead to gastric cancer. H. pylori expresses the outer membrane HopQ protein at the earliest stages of infection. Therefore, HopQ is a highly reliable candidate as a biomarker for H. pylori detection in saliva samples. In this work, an H. pylori immunosensor is based on detecting HopQ as an H. pylori biomarker in saliva. The immunosensor was developed by surface modification of screen-printed carbon electrodes (SPCE) with MWCNT-COOH decorated with gold nanoparticles (AuNP) followed by HopQ capture antibody grafting on SPCE/MWCNT/AuNP surface using EDC/S-NHS chemistry. The sensor performance was investigated utilizing various methods, such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscope (SEM) coupled with energy-dispersive X-ray spectroscopy (EDX). H. pylori detection performance in spiked saliva samples was evaluated by square wave voltammetry (SWV). The sensor is suitable for HopQ detection with excellent sensitivity and linearity in the 10 pg/mL-100 ng/mL range, with a 2.0 pg/mL limit of detection (LOD) and an 8.6 pg/mL limit of quantification (LOQ). The sensor was tested in saliva at 10 ng/mL, and recovery of 107.6% was obtained by SWV. From Hill's model, the dissociation constant Kd for HopQ/HopQ antibody interaction is estimated to be 4.60 × 10^-10 mg/mL. The fabricated platform shows high selectivity, good stability, reproducibility, and cost-effectiveness for H. pylori early detection due to the proper choice of biomarker, the nanocomposite material utilization to boost the SPCE electrical performance, and the intrinsic selectivity of the antibody-antigen approach. Additionally, we provide insight into possible future aspects that researchers are recommended to focus on.

Establishment of a modified Kyoto classification scoring model and its significance in the diagnosis of Helicobacter pylori current infection

BACKGROUND AND AIMS

We aimed to establish a modified model of the Kyoto classification score and verify its accuracy for predicting Helicobacter pylori (HP) infection during endoscopy.

METHODS

Patients who underwent gastroscopy from June 2020 to March 2021 were included in this study. Atrophy, intestinal metaplasia, hypertrophy of the gastric fold, nodularity, diffuse redness, sticky mucus, spotty redness, xanthoma, map-like redness, fundic gland polyp, and regular arrangement of collecting venules (RAC) were recorded according to the Kyoto classification of gastritis. The HP infection status of participants was determined by a ¹³C breath test, anti-HP antibody, and histopathologic hematoxylin and eosin staining. The modified Kyoto classification scoring model was established based on univariate analysis and logistic regression analysis. The modified scoring model was used to judge the status of HP infection in patients undergoing gastroscopy from July to September 2021 and to evaluate the accuracy of the prediction.

RESULTS

Of 667 participants in the derivation dataset, 326 cases had HP infection and 341 cases did not. Atrophy, hypertrophy of the gastric fold, nodularity, diffuse redness, sticky mucus, and spotty redness were associated with HP current infection. Thus, a new scoring model, termed the modified Kyoto classification scoring model, was constructed that included atrophy, hypertrophy of the gastric fold, nodularity, diffuse redness, sticky mucus, spotty redness, fundic gland polyp, and RAC as indicators. To test the model, 808 subjects, including 251 HP-positive patients, comprised the validation dataset.

CONCLUSIONS

The modified Kyoto classification scoring model improved the accuracy of endoscopic determination of HP current infection and has clinical application potential in the Chinese population.

The lung, the niche, and the microbe: Exploring the lung microbiome in cancer and immunity

The lung is a complex and unique organ system whose biology is strongly influenced by environmental exposure, oxygen abundance, connection to extrapulmonary systems via a dense capillary network, and an array of immune cells that reside in the tissue at steady state. The lung also harbors a low biomass community of commensal microorganisms that are dynamic during both health and disease with the capacity to modulate regulatory immune responses during diseases such as cancer. Lung cancer is the third most common cancer worldwide with the highest mortality rate amongst cancers due to the difficulty of an early diagnosis. This review discusses the current body of work addressing the interactions between the lung microbiota and the immune system, and how these two components of the pulmonary system are linked to lung cancer development and outcomes. Bringing in lessons from broader studies examining the effects of the gut microbiota on cancer outcomes, we highlight many challenges and gaps in this nascent field.

Correlations between Endoscopic and Histopathological Assessment of Helicobacter pylori-Induced Gastric Pathology-A Cross-Sectional Retrospective Study

Helicobacter pylori (H. pylori) infects about half of the world’s population and can lead to premalignant lesions and gastric cancer. Updated data about the correlation of histopathological diagnostics with endoscopic diagnostics are scarce. The objective of this study was to identify the concordance between endoscopic and histopathologic findings, with a focus on premalignant lesions. We performed a cross sectional, retrospective study over a 4-year period (2017−2021) on adult patients with dyspeptic symptoms and positive RUT (rapid urease test) in a single hospital centre, with a total of 133 patients infected with H. pylori being included in the study. Statistical associations between endoscopic appearance and histopathological results were found for atrophic antral gastritis (p = 0.001), intestinal metaplasia of the antrum (p = 0.018), gastric polyps (p < 0.001) and gastric corpus cancer (p = 0.012). Females were more likely to be diagnosed through endoscopy with gastric atrophy or intestinal metaplasia (p = 0.031), while chronic atrophic gastritis in corpus was more prevalent in patients older than 65 (p = 0.024). Overall, our study reveals only 21% concordance between Giemsa stain and RUT, highlighting the importance of combining rapid testing with endoscopic and histopathological diagnostic methods for a more accurate early diagnosis and prevention of gastric cancer.

Insulin-like growth factor 1 serum levels in different stages of gastric cancer and their association with Helicobacter pylori status

High serum insulin-like growth factor 1 (IGF-1) and positive Helicobacter pylori (H. pylori) may increase the risk of gastric cancer (GC). We aimed to investigate IGF-1 serum levels in different stages of GC patients and their association with H. pylori status. A total of 90 participants, including 60 GC patients and 30 noncancerous (NC) individuals, were included in the present study. IGF-1 serum levels and candidate proteins were assessed using enzyme-linked immunosorbent and immunohistochemistry techniques. Likewise, Giemsa staining was applied to detect H. pylori infection. The candidate genes' expression, including IGF-1R, PI3KCA, AKT1, mTOR1, KRAS, BRAF, and ERK1, was also evaluated by a real-time PCR assay. The results of advanced GC stages indicated a significantly high IHC score for IGF-1R and phosphorylated AKT, mTOR, and ERK proteins compared to the early stages. Moreover, IGF-1 serum levels and the expression of candidate genes were considerably increased in the advanced GC patients compared to the early stages and the positive H. pylori status compared to the negative H. pylori status (P < 0.05). As a result, high IGF-1 serum levels and positive H. pylori status may be correlated with gastric tumor progression, and the inhibition of IGF-1 and the eradication of H. pylori infection might be new therapeutic targets in GC patients.

Human gastric fibroblasts ameliorate A20-dependent cell survival in co-cultured gastric epithelial cells infected by Helicobacter pylori

Crosstalk within the gastric epithelium, which is closely in contact with stromal fibroblasts in the gastric mucosa, has a pivotal impact in proliferation, differentiation and transformation of the gastric epithelium. The human pathogen Helicobacter pylori colonises the gastric epithelium and represents a risk factor for gastric pathophysiology. Infection of H. pylori induces the activation of the transcription factor nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), which is involved in the pro-inflammatory response but also in cell survival. In co-cultures with human gastric fibroblasts (HGF), we found that apoptotic cell death is reduced in the polarised human gastric cancer cell line NCI-N87 or in gastric mucosoids during H. pylori infection. Interestingly, suppression of apoptotic cell death in NCI-N87 cells involved an enhanced A20 expression regulated by NF-κB activity in response to H. pylori infection. Moreover, A20 acts as an important negative regulator of caspase-8 activity, which was suppressed in NCI-N87 cells during co-culture with gastric fibroblasts. Our results provide evidence for NF-κB-dependent regulation of apoptotic cell death in cellular crosstalk and highlight the protective role of gastric fibroblasts in gastric epithelial cell death during H. pylori infection.

Ten-day concomitant and sequential therapy for Helicobacter pylori effective in region with high antibiotic resistance rates

BACKGROUND

Increasing antibiotic-resistant Helicobacter pylori (H. pylori) strains complicate efforts to eradicate infection. In regions with high dual resistance to both clarithromycin and metronidazole, bismuth quadruple therapy is recommended. But, with lack of easy availability of bismuth, the (non-bismuth) concomitant and sequential regimens are used commonly as first-line therapy. Recent reports indicate suboptimal results with sequential therapy in such regions. We aimed to compare the efficacy of concomitant therapy vs. sequential therapy in the eradication of H. pylori in a region with high antibiotic resistance rates, and to compare adherence rates and adverse events with the regimens.

METHODS

One hundred and twenty-four consecutive H. pylori-infected patients (diagnosed using rapid urease test or urea breath test) were randomized to receive sequential or concomitant therapy for 10 days each. Four weeks after treatment completion, urea breath test was done to confirm eradication of the infection. Cure rates were compared between the two regimens and note was made of adherence rates and adverse events.

RESULTS

Concomitant therapy showed a statistically non-significant higher cure rate compared to sequential therapy in intention-to-treat (87.1% vs. 81.4%%, p = 0.46) and per-protocol (94.7% vs. 83.9%, p = 0.07) analyses. Both the regimens were well tolerated and showed similar adherence rates (p = 1.00) and incidence of adverse events (p = 0.44).

CONCLUSION

In a region with high dual resistance, both concomitant and sequential therapy for H. pylori infection achieved eradication rates >80%, but concomitant therapy showed a statistically non-significant higher cure rate, with similar adherence and adverse event profiles.

Tumor Molecular and Microenvironment Characteristics in EBV-Associated Malignancies as Potential Therapeutic Targets: Focus on Gastric Cancer

Although most people are infected with Epstein-Barr Virus (EBV) during their lifetime, only a minority of them develop an EBV-associated malignancy. EBV acts in both direct and indirect ways to transform infected cells into tumor cells. There are multiple ways in which the EBV, host, and tumor environment interact to promote malignant transformation. This paper focuses on some of the mechanisms that EBV uses to transform the tumor microenvironment (TME) of EBV-associated gastric cancer (EBVaGC) for its benefit, including overexpression of Indoleamine 2,3-Dioxygenase 1 (IDO1), synergism between H. pylori and EBV co-infection, and M1 to M2 switch. In this review, we expand on different modalities and combinatorial approaches to therapeutically target this mechanism.

The interaction of Helicobacter pylori with cancer immunomodulatory stromal cells: New insight into gastric cancer pathogenesis

Gastric cancer is the fourth most common cause of cancer-linked deaths in the world. Gastric tumor cells have biological characteristics such as rapid proliferation, high invasiveness, and drug resistance, which result in recurrence and poor survival. Helicobacter pylori (H. pylori) has been proposed as a first-class carcinogen for gastric cancer according to the 1994 world health organization (WHO) classification. One of the important mechanisms by which H. pylori affects the gastric environment and promotes carcinogenesis is triggering inflammation. H. pylori induces an inflammatory response and a plethora of different signal transduction processes, leading to gastric mucosal disturbance, chronic gastritis, and a multi-step complex pathway that initiates carcinogenesis. It seems undeniable that the interaction between various cell types, including immune cells, gastric epithelium, glands, and stem cells, is vital for the progression and development of carcinogenesis concerning H. pylori. The interactions of H. pylori with surrounding cells play a key role in cancer progression. In this review, we discuss the interplay between H. pylori and tumor-supportive cells, including mesenchymal stem cells (MSCs), cancer-associated fibroblasts (CAFs), tumor-associated macrophages (TAMs), and myeloid derived-suppressor cells (MDSCs) in gastric cancer. It is hoped that clarifying the specific mechanisms for 'cross-talk' between H. pylori and these cells will provide promising strategies for developing new treatments.

The role of infections in the causation of cancer in Kenya

Cancer constitutes a major health care burden in the world today with the situation worsening in resource poor settings as seen in most Sub-Saharan African (SSA) countries. Infections constitute by far the most common risk factors for cancer in SSA and being a typical country in this region, Kenya has experienced an upsurge in the incidence of various types of cancers in the last few decades. Although there is limited population-based data in Kenya of infections-associated cancers, this review provides an up-to-date literature-based discussion on infections-associated cancers, their pathogenesis, and preventive approaches in the country. The primary infectious agents identified are largely viral (human immunodeficiency virus, human papillomavirus (HPV), Kaposi's sarcoma-associated herpes virus, Epstein-Barr virus, hepatitis B virus (HBV), hepatitis C virus), and also bacterial: Helicobacter pylori and parasitic: Schistosomiasis haematobium. Cancers associated with infections in Kenya are varied but the predominant ones are Non-Hodgkin lymphoma, Kaposi's sarcoma, Hodgkin lymphoma, Burkitt's lymphoma, cervical, liver, and gastric cancers. The mechanisms of infections-induced carcinogenesis are varied but they mainly seem to stem from disruption of signaling, chronic inflammation, and immunosuppression. Based on our findings, actionable cancer-preventive measures that are economically feasible and aligned with existing infrastructure in Kenya include screening and treatment of infections, implementation of cancer awareness and screening, and vaccination against infections primarily HBV and HPV. The development of vaccines against other infectious agents associated with causation of cancer remains also as an important goal in cancer prevention.

Cancer Stem Cells in Tumor Microenvironment of Adenocarcinoma of the Stomach, Colon, and Rectum

Gastrointestinal adenocarcinomas are one of the world's deadliest cancers. Cancer stem cells and the tissue microenvironment are highly regulated by cell and molecular mechanisms. Cancer stem cells are essential for maintenance and progression and are associated with resistance to conventional treatments. This article reviews the current knowledge of the role of the microenvironment during the primary establishment of gastrointestinal adenocarcinomas in the stomach, colon, and rectum and its relationship with cancer stem cells. We also describe novel developments in cancer therapeutics, such as targeted therapy, and discuss the advantages and disadvantages of different treatments for improving gastrointestinal cancer prognosis.

USP48 and A20 synergistically promote cell survival in Helicobacter pylori infection

The human pathogen Helicobacter pylori represents a risk factor for the development of gastric diseases including cancer. The H. pylori-induced transcription factor nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) is involved in the pro-inflammatory response and cell survival in the gastric mucosa, and represents a trailblazer of gastric pathophysiology. Termination of nuclear NF-κB heterodimer RelA/p50 activity is regulated by the ubiquitin-RING-ligase complex elongin-cullin-suppressor of cytokine signalling 1 (ECS^SOCS1), which leads to K48-ubiquitinylation and degradation of RelA. We found that deubiquitinylase (DUB) ubiquitin specific protease 48 (USP48), which interacts with the COP9 signalosome (CSN) subunit CSN1, stabilises RelA by deubiquitinylation and thereby promotes the transcriptional activity of RelA to prolong de novo synthesis of DUB A20 in H. pylori infection. An important role of A20 is the suppression of caspase-8 activity and apoptotic cell death. USP48 thus enhances the activity of A20 to reduce apoptotic cell death in cells infected with H. pylori. Our results, therefore, define a synergistic mechanism by which USP48 and A20 regulate RelA and apoptotic cell death in H. pylori infection.

Saccharomyces boulardii Allows Partial Patients to Avoid Reusing Bismuth Quadruple for Helicobacter pylori Rescue Therapy: A Single-Center Randomized Controlled Study

Background

The increasing rate of drug resistance often leads to Helicobacter pylori (H. pylori) eradication failure and needs the rescue therapy. Thus, the exploration of new rescue therapeutic regimens is important. The present study was designed to test the beneficial effects of Saccharomyces boulardii (S.boulardii) prior to H. pylori rescue therapy basing on bismuth quadruple.

Methods

One hundred H. pylori-infected patients were randomly divided into two groups: study group and control group. Patients in the study group (n=50) underwent two-stages therapy: patients started with S.boulardii monotherapy for 2 weeks, and then tested for H. pylori infection after resting for 4 weeks without any therapy, patients who were still positive for H. pylori continued with bismuth quadruple eradication therapy. For the control group (n=50), all patients were observed and were not treated with any gastric drugs or antibiotics for 6 weeks, then those who were still positive for H. pylori received the same eradication therapy as the study group. Eradication rate, adverse events and the cost-effectiveness of two regimens were analyzed in this study.

Results

The H.pylori eradication rate of ITT (intent-to-treat) analysis and PP (per-protocol) analysis in the first phase of treatment were significantly higher in the study group than the control groups respectively (28.0% vs 2.0%, p<0.001 and 30.4% vs 2.1% p<0.001). For the total treatment effect, there were no significant differences in the eradication rate of ITT analysis (78.0% vs 80.0%) or PP analysis (90.7% vs 88.9%) between the study group and the control group. The cost‐effectiveness ratio of the study group was slightly higher than that of the control group (8.95 vs 8.55). There were two patients in the study group and four patients in the control group with the adverse events, respectively. There was no significant difference on the incidence of adverse events between the two groups (p=0.68).

Conclusion

S.boulardii may serve as a beneficial treatment option before H. pylori rescue therapy since it callowed partial patients to avoid reusing bismuth quadruple.

Analysis of cathepsin S expression in gastric adenocarcinoma and in Helicobacter pylori infection

BACKGROUND

Recent experimental studies have suggested a potential link between cathepsin S (CTTS) and gastric adenocarcinoma progression. Herein, we aimed to evaluate the expression of CTTS in gastric adenocarcinoma in patients who underwent curative-intent surgical resection.

METHODS

This was a cross-sectional study that included two groups: gastric adenocarcinoma (n = 42) and gastritis (n = 50). The gastritis group was then subdivided into H. pylori-positive (n = 25) and H. pylori-negative (n = 25) groups. Gastric tissue samples were analysed to determine CTTS expression through immunohistochemistry. Samples were obtained by oesophagogastroduodenoscopy or surgical specimens.

RESULTS

In patients with gastritis, the age ranged from 18 to 78 years. Among them, 34% were male, and 66% were female. In patients with gastric adenocarcinoma, the age ranged from 37 to 85 years. Among them, 50% were male. When comparing the expression of CTTS between the two groups, only 16% of the gastritis samples had an expression higher than 25%. Alternatively, among patients with gastric adenocarcinoma, 19% had expression between 25-50%, 14.3% between 51-75%, and 26.2% had expression higher than 75% (p < 0.001). In the gastritis group, CTTS expression was significantly higher in patients with a positive test for H. pylori than negative test for H. pylori: 87.5% and 38.5%, respectively (p<0.001). There was no statistically significant association between CTTS positivity and clinicopathological variables, including tumour staging, histological type, angiolymphatic invasion, recurrence, current status and death.

CONCLUSION

CTTS expression is higher in gastric adenocarcinoma samples. Patients with gastritis due to H. pylori also show a higher expression of CTTS than patients with negative results for this bacterium.

Prevalence of Helicobacter pylori in Non-Cardia Gastric Cancer in China: A Systematic Review and Meta-Analysis

Non-cardia gastric cancer was significantly associated with Helicobacter pylori (H. pylori) infection. Reducing H. pylori prevalence was an important prevention strategy for non-cardia gastric cancer. However, national-level data on the H. pylori prevalence in non-cardia gastric cancer were limited in China. Therefore, we conducted this study to estimate the pooled prevalence of H. pylori in non-cardia gastric cancer in China. We searched PubMed, Embase, the Cochrane Library, China National Knowledge Infrastructure (CNKI), Wan Fang, and VIP Database for Chinese Technical Periodicals for studies reporting H. pylori prevalence in non-cardia gastric cancer in China which were published before September 1, 2021. Pooled prevalence was calculated using a random-effect model. Subgroup analysis and meta-regression were used to explore the potential sources of heterogeneity. Egger’s test and funnel plot were used to assess publication bias. A total number of 55 studies with 5324 cases of non-cardia gastric cancer were included in this study. The pooled prevalence of H. pylori in non-cardia gastric cancer in China was 66.5% (95%CI: 62%-71%, I²=93.8%, P<0.0001). In subgroup analysis, a significant difference in the prevalence of H. pylori in non-cardia gastric cancer was noted when stratified by geographic region of China (P=0.0112). The highest H. pylori prevalence (78.9%, 95%CI: 69.9%-87.8%) was noted in Northwest China and the lowest (53.1%, 95%CI: 38.9%-67.3%) was in North China. In meta-regression, a significant association between H. pylori prevalence and geographic region was found, while type of sample, H. pylori testing method, diagnosis period, detection timing, type of study design, quality grade, publication year, and sample size were not associated with the prevalence of H. pylori in non-cardia gastric cancer (P>0.05). A large proportion of non-cardia gastric cancers were associated with H. pylori infection in China, emphasizing the possible benefits of H. pylori eradication for the prevention and control of non-cardia gastric cancer.

An Overview of Autophagy in Helicobacter pylori Infection and Related Gastric Cancer

Helicobacter pylori (H. pylori) infection is considered a class I carcinogen in the pathogenesis of gastric cancer. In recent years, the interaction relationship between H. pylori infection and autophagy has attracted increasing attention. Most investigators believe that the pathogenesis of gastric cancer is closely related to the formation of an autophagosome-mediated downstream signaling pathway by H. pylori infection-induced cells. Autophagy is involved in H. pylori infection and affects the occurrence and development of gastric cancer. In this paper, the possible mechanism by which H. pylori infection affects autophagy and the progression of related gastric cancer signaling pathways are reviewed.

Helicobacter species binding to the human gastric mucosa

Helicobacter pylori infects half of the world population, being associated with several gastric disorders, such as chronic gastritis and gastric carcinoma. The Helicobacter genus also includes other gastric helicobacters, such as H. heilmannii¸ H. ailurogastricus, H. suis, H. felis, H. bizzozeronii, and H. salomonis. These gastric helicobacters colonize both the human and animal stomach. The prevalence of gastric non-Helicobacter pylori Helicobacter (NHPH) species in humans has been described as low, and the in vitro binding to the human gastric mucosa was never assessed. Herein, human gastric tissue sections were used for the evaluation of the tissue glycophenotype and for the binding of gastric NHPH strains belonging to different species. Histopathological evaluation showed that 37.5% of the patients enrolled in our cohort presented chronic gastritis, while the presence of neutrophil or eosinophilic activity (chronic active gastritis) was observed in 62.5% of the patients. The secretor phenotype was observed in 68.8% of the individuals, based on the expression of Lewis B antigen and binding of the UleX lectin. The in vitro binding assay showed that all the NHPH strains evaluated were able to bind, albeit in low frequency, to the human gastric mucosa. The H. heilmannii, H. bizzozeronii, and H. salomonis strains displayed the highest binding ability both to the gastric superficial epithelium and to the deep glands. Interestingly, we observed binding of NHPH to the gastric mucosa of individuals with severe chronic inflammation and intestinal metaplasia, suggesting that NHPH binding may not be restricted to the healthy gastric mucosa or slight chronic gastritis. Furthermore, the in vitro binding of NHPH strains was observed both in secretor and non-secretor individuals in a similar frequency. In conclusion, this study is the first report of the in vitro binding ability of gastric NHPH species to the human gastric mucosa. The results suggest that other glycans, besides the Lewis antigens, could be involved in the bacterial adhesion mechanism; however, the molecular intervenients remain unknown.

H. pylori CagA activates the NLRP3 inflammasome to promote gastric cancer cell migration and invasion

OBJECTIVE

The CagA (cytotoxin-related gene A, CagA) protein is an important factor for the pathogenicity of Helicobacter pylori (H. pylori). Although H. pylori has previously been shown to activate the NLRP3 inflammasome, it remains unclear what role CagA plays in this process. In the current study, we aimed to investigate the effect of CagA on NLRP3 activation and how it is linked to gastric cancer cell migration and invasion.

METHODS

CagA positive H. pylori strain (Hp/CagA⁺) and CagA gene knockout mutant (Hp/ΔCagA) infected and the pcDNA3.1/CagA plasmid transfected gastric epithelial cell lines, respectively. The morphological alterations of cells under a microscope; the NLRP3 inflammasome-related markers: NLRP3, caspase-1, and ASC protein levels were detected by Western blot, IL-1β and IL-18 levels were determined by ELISA; cell migration and invasion were determined by transwell assay; and the pyroptosis levels and intracellular ROS were determined by flow cytometry analysis. Then, pretreated with 5 mM NAC for 2 h and subsequently transfected with the pcDNA3.1/CagA plasmid for 48 h, the effects of NAC pretreatment on CagA-induced NLRP3 inflammasome-related markers expression and cell pyroptosis were examined, finally assessed the effect of CagA on migration and invasion in NLRP3-silenced cells.

RESULTS

We found that Hp/CagA⁺ strain infection and pcDNA3.1/CagA vector transfection result in NLRP3 inflammasome activation, generation of intracellular ROS, and increased invasion and migration of gastric cancer cells. Moreover, we found that ROS inhibition via NAC effectively blocks NLRP3 activation and pyroptosis. Silencing of NLRP3 reduces the effects of CagA on gastric cancer cell migration and invasion.

CONCLUSION

Our study shows that CagA can promote the invasion and migration of gastric cancer cells by activating NLRP3 inflammasome pathway. These findings provide novel insights into the mechanism of gastric cancer induction by H. pylori.

Microbiota and IPF: hidden and detected relationships

Lung microbiota (LM) is an interesting new way to consider and redesign pathogenesis and possible therapeutic approach to many lung diseases, such as idiopathic pulmonary fibrosis (IPF), which is an interstitial pneumonia with bad prognosis. Chronic inflammation is the basis but probably not the only cause of lung fibrosis and although the risk factors are not completely clear, endogenous factors (e.g. gastroesophageal reflux) and environmental factors like cigarette smoking, industrial dusts, and precisely microbial agents could contribute to the IPF development. It is well demonstrated that many bacteria can cause epithelial cell injuries in the airways through induction of a host immune response or by activating flogosis mediators following a chronic, low-level antigenic stimulus. This persistent host response could influence fibroblast responsiveness suggesting that LM may play a role in repetitive alveolar injury in IPF. We reviewed literature regarding not only bacteria but also the role of virome and mycobiome in IPF. In fact, some viruses such as hepatitis C virus or certain fungi could be etiological agents or co-factors in the IPF progress. We aim to illustrate how the cross-talk between different local microbiotas throughout specific axis and immune modulation governed by microorganisms could be at the basis of lung dysfunctions and IPF development. Finally, since the future direction of medicine will be personalized, we suggest that the analysis of LM could be a goal to research new therapies also in IPF.

Role of Helicobacter pylori and Other Environmental Factors in the Development of Gastric Dysbiosis

Microbiomes are defined as complex microbial communities, which are mainly composed of bacteria, fungi, and viruses residing in diverse regions of the human body. The human stomach consists of a unique and heterogeneous habitat of microbial communities owing to its anatomical and functional characteristics, that allow the optimal growth of characteristic bacteria in this environment. Gastric dysbiosis, which is defined as compositional and functional alterations of the gastric microbiota, can be induced by multiple environmental factors, such as age, diet, multiple antibiotic therapies, proton pump inhibitor abuse, H. pylori status, among others. Although H. pylori colonization has been reported across the world, chronic H. pylori infection may lead to serious consequences; therefore, the infection must be treated. Multiple antibiotic therapy improvements are not always successful because of the lack of adherence to the prescribed antibiotic treatment. However, the abuse of eradication treatments can generate gastric dysbiotic states. Dysbiosis of the gastric microenvironment induces microbial resilience, due to the loss of relevant commensal bacteria and simultaneous colonization by other pathobiont bacteria, which can generate metabolic and physiological changes or even initiate and develop other gastric disorders by non-H. pylori bacteria. This systematic review opens a discussion on the effects of multiple environmental factors on gastric microbial communities.

Pathogens and Carcinogenesis: A Review

Cancer is a global health problem associated with genetics and unhealthy lifestyles. Increasingly, pathogenic infections have also been identified as contributors to human cancer initiation and progression. Most pathogens (bacteria, viruses, fungi, and parasites) associated with human cancers are categorized as Group I human carcinogens by the International Agency for Research on Cancer, IARC. These pathogens cause carcinogenesis via three known mechanisms: persistent infection that cause inflammation and DNA damage, initiation of oncogene expression, and immunosuppression activity of the host. In this review, we discuss the carcinogenesis mechanism of ten pathogens, their implications, and some future considerations for better management of the disease. The pathogens and cancers described are Helicobacter pylori (gastric cancer), Epstein-Barr virus (gastric cancer and lymphoma), Hepatitis B and C viruses (liver cancer), Aspergillus spp. (liver cancer), Opisthorchis viverrine (bile duct cancer), Clonorchis sinensis (bile duct cancer), Fusobacterium nucleatum (colorectal cancer), Schistosoma haematobium (bladder cancer); Human Papillomavirus (cervical cancer), and Kaposi's Sarcoma Herpes Virus (Kaposi's sarcoma).

Novel Anthocyanin-Based Colorimetric Assay for the Rapid, Sensitive, and Quantitative Detection of Helicobacter pylori

Several different diagnostic tests have been reported for rapid, sensitive, and economical detection of bacterial pathogens, but most lack widespread and practical use in the clinic. In this study, we used anthocyanins from red cabbage (Brassica oleracea) as a natural pH indicator and, for the first time, incorporated this agent into a simple, rapid, and economical colorimetric strategy for the detection of Helicobacter pylori (H. pylori) (RCE@test). We prepared two sets of RCE@test solutions (test 1 is purple, and test 2 is blue) in different forms, including liquid, adsorbed filter paper, and agar, and investigated the performance of each RCE@test as a function of the test volume, H. pylori concentration, and reaction time. To elucidate the effect of the pathophysiological environment on these RCE@tests, H. pylori in an artificial gastric fluid was also detected. The 10 and 1 CFU/mL H. pylori suspensions were detected in 15 min and 3 h, respectively, and the limit of detection was determined down to 1 CFU/mL. We experimentally demonstrated the advantages of the RCE@test for detection of H. pylori by comparing it to a commercially available rapid urease test, the "CLO test (Campylobacter-like organism test)". In addition to colorimetric detection by the naked eyes, RGB (Red Green Blue) and Delta-E analysis in image-processing software was run to quantitatively monitor changes of color in the RCE@test using a smartphone application. Finally, we propose that this test provides simple, effective, rapid, and inexpensive detection and that it can be easily implemented for clinical use.

Sustained Exposure to Helicobacter pylori Lysate Inhibits Apoptosis and Autophagy of Gastric Epithelial Cells

Helicobacter pylori is designated as a class I carcinogen of human gastric cancer following long-term infection. During this process, H. pylori bacteria persist in proliferation and death, and release bacterial components that come into contact with gastric epithelial cells and regulate host cell function. However, the impact of long-term exposure to H. pylori lysate on the pathological changes of gastric cells is not clear. In this study, we aimed to investigate the regulation and mechanisms involved in gastric cell dysfunction following continuous exposure to H. pylori lysate. We co-cultured gastric cell lines GES-1 and MKN-45 with H. pylori lysate for 30 generations, and we found that sustained exposure to H. pylori lysate inhibited GES-1 cell invasion, migration, autophagy, and apoptosis, while it did not inhibit MKN-45 cell invasion or migration. Furthermore, Mongolian gerbils infected with H. pylori ATCC 43504 strains for 90 weeks confirmed the in vitro results. The clinical and in vitro data indicated that sustained exposure to H. pylori lysate inhibited cell apoptosis and autophagy through the Nod1-NF-κB/MAPK-ERK/FOXO4 signaling pathway. In conclusion, sustained exposure to H. pylori lysate promoted proliferation of gastric epithelial cells and inhibited autophagy and apoptosis via Nod1-NF-κB/MAPK-ERK/FOXO4 signaling pathway. In the process of H. pylori-induced gastric lesions, H. pylori lysate plays as an "accomplice" to carcinogenesis.

Epidemiology of esophageal cancer: update in global trends, etiology and risk factors

Esophageal cancer is the eighth most common type of cancer worldwide and constitutes the sixth leading cause of cancer deaths. It is characterized by its high mortality rate, poor prognosis at time of diagnosis and variability based on geographic location. Present day, the prevalence of esophageal cancer is in transition. Although esophageal squamous cell carcinoma continues to be the most prevalent type worldwide, esophageal adenocarcinoma is quickly becoming the most prevalent type in developed countries. Risk factors for the development of esophageal squamous cell carcinoma include low socioeconomic status, consumption of tobacco, alcohol, hot beverages, and nitrosamines. Additionally, micronutrient deficiencies have also been linked to the development of esophageal squamous cell cancer. These include vitamin C, vitamin E, and folate. With respect to esophageal adenocarcinoma, risk factors include Barrett's esophagus, gastroesophageal reflux disease, obesity, and tobacco consumption. Screening for esophageal cancer will likely play an essential role in prevention, and consequently, mortality in the future. Present day, there are no established guidelines for esophageal squamous cell cancer screening. Guidelines for esophageal adenocarcinoma are more well established but lack concrete evidence in the form of randomized controlled trials. This review will discuss the epidemiology, risk factors, and current prevention strategies for esophageal cancer in depth. It is our aim to raise awareness on the aforementioned topics to increase public health efforts in eradicating this disease.

Non‑coding RNAs that regulate the Wnt/β‑catenin signaling pathway in gastric cancer: Good cop, bad cop? (Review)

Gastric cancer (GC) is one of the most common causes of cancer‑related mortality worldwide. Despite remarkable progress in the diagnosis and treatment of GC, a large number of cases are diagnosed as advanced GC, and treatment failure occurs. Emerging evidence has shown that non‑coding RNAs (ncRNAs), especially microRNAs (miRNAs) and long non‑coding RNAs (lncRNAs), play a vital role in the tumorigenesis and development of GC. Moreover, the pathogenesis of GC is closely related to aberrant activation of the Wnt (Wingless‑type MMTV integration site family) signaling pathway. ncRNAs serve as potential novel biomarkers in the clinical examination, prognosis and therapeutic targeting of GC. Furthermore, dysregulation of ncRNAs has been demonstrated to affect tumor initiation, epithelial‑mesenchymal transition (EMT), angiogenesis, tumor development, invasion, metastasis and resistance to therapy via the Wnt/β‑catenin signaling pathway. This review focuses on the role of ncRNAs in modulating the Wnt/β‑catenin signaling pathway in the pathogenesis of GC, which may provide a reference for the clinical diagnosis and treatment of GC.

Dysregulated Expression of Apoptosis-Associated Genes and MicroRNAs and Their Involvement in Gastric Carcinogenesis

PURPOSE

Analyze the expression of caspase-9, Smac/DIABLO, XIAP, let-7a, and let-7b in patients with normal gastric tissue, chronic gastritis, and gastric adenocarcinoma.

METHODS

The expression of caspase-9, Smac/DIABLO, XIAP, let-7a, and let-7b by qRT-PCR was analyzed in 158 samples from 53 patients with normal gastric mucosa, 86 with chronic gastritis, and 19 with gastric cancer.

RESULTS

The comparison between the gastric cancer and the control group revealed a decreased expression of caspase-9 in gastric cancer tissues; considering the Helicobacter pylor presence, comparable results were revealed. Smac/DIABLO was increased in gastric cancer cells, while XIAP demonstrated no significant difference in the gene expression. The microRNA analysis revealed a decreased expression of let-7a and let-7b in samples positive to H. pylori infection and in gastric cancer group, regardless of the presence of the bacterium.

CONCLUSION

Our study provided some evidence of low activity of the intrinsic apoptosis pathway, as well as the influence of H. pylori on let-7a and let-7b expression.

Gastroprotective effect of phytoncide extract from Pinus koraiensis pinecone in Helicobacter pylori infection

For centuries, herbs have been used by traditional therapists around the world to treat gastrointestinal tract disorders, such as gastritis. We hypothesized that the anti-Helicobacter pylori properties of phytoncide, which is extracted from pinecone waste, would facilitate use as a natural gastroprotective product to treat gastrointestinal tract disorders. Thus, we investigated in vitro antibacterial efficacy against H. pylori by agar diffusion assay. To determine the gastroprotective properties of phytoncide, we conducted hematoxylin and eosin staining, performed assays for the detection of the cytotoxin gene, and evaluated pro-inflammatory cytokine expression in H. pylori-infected C57BL/6 mice. Phytoncide significantly inhibited the survival of H. pylori in the gastrointestinal system of C57BL/6 mice. Reduction of gastric severity in H. pylori-infected mice was associated with reductions in the expression levels of pro-inflammatory cytokines in the gastric mucosa, and of the cytotoxin CagA gene in phytoncide treated groups (P < 0.05 and P < 0.01). In conclusion, phytoncide significantly inhibited the growth of H. pylori in gastro tissue, possibly due to the abundant α-pinene present in the phytoncide as detected by HPLC analysis. Further studies are needed to validate our findings, but we suggest that phytoncide has the potential to be used as a natural ingredient in anti-H. pylori products.

Diagnosis and Management of Gastric Intestinal Metaplasia: Current Status and Future Directions

Gastric intestinal metaplasia (GIM) is a known premalignant condition of the human stomach along the pathway to gastric cancer (GC). Histologically, GIM represents the replacement of normal gastric mucosa by mucin-secreting intestinal mucosa. Helicobacter pylori infection is the most common etiologic agent of GIM development worldwide. The prevalence of GIM is heterogeneous among different regions of the world and correlates with the population endemicity of H. pylori carriage, among other environmental factors. GC remains the third leading cause of cancer-related mortality globally. GIM is usually diagnosed by upper endoscopy with biopsy, and histologic scoring systems have been developed to risk-stratify patients at highest risk for progression to GC. Several recent endoscopic imaging modalities may improve the optical detection of GIM and early GC. Appropriate surveillance of GIM may be cost effective and represents an opportunity for the early diagnosis and therapy of GC. Certain East Asian nations have established population-level programs for the screening and surveillance of GIM; guidelines regarding GIM surveillance have also recently been published in Europe. By contrast, few data exist regarding the appropriateness of surveillance of GIM in the United States. In this review, we discuss the pathogenesis, epidemiology, diagnosis, and management of GIM with an emphasis on the role of appropriate endoscopic surveillance.

Gastric Damage and Cancer-Associated Biomarkers in Helicobacter pylori-Infected Children

Helicobacter pylori (H. pylori) is well-known to be involved in gastric carcinogenesis, associated with deregulation of cell proliferation and epigenetic changes in cancer-related genes. H. pylori infection is largely acquired during childhood, persisting long-term in about half of infected individuals, a subset of whom will go on to develop peptic ulcer disease and eventually gastric cancer, however, the sequence of events leading to disease is not completely understood. Knowledge on carcinogenesis and gastric damage-related biomarkers is abundant in adult populations, but scarce in children. We performed an extensive literature review focusing on gastric cancer related biomarkers identified in adult populations, which have been detected in children infected with H. pylori. Biomarkers were related to expression levels (RNA or protein) and/or methylation levels (DNA) in gastric tissue or blood of infected children as compared to non-infected controls. In this review, we identified 37 biomarkers of which 24 are over expressed, three are under expressed, and ten genes are significantly hypermethylated in H. pylori-infected children compared to healthy controls in at least 1 study. Only four of these biomarkers (pepsinogen I, pepsinogen II, gastrin, and SLC5A8) have been studied in asymptomatically infected children. Importantly, 13 of these biomarkers (β-catenin, C-MYC, GATA-4, DAPK1, CXCL13, DC-SIGN, TIMP3, EGFR, GRIN2B, PIM2, SLC5A8, CDH1, and VCAM-1.) are consistently deregulated in infected children and in adults with gastric cancer. Future studies should be designed to determine the clinical significance of these changes in infection-associated biomarkers in children and their persistence over time. The effect of eradication therapy over these biomarkers in children if proven significant, could lead to modifications in treatment guidelines for younger populations, and eventually promote the development of preventive strategies, such as vaccination, in the near future.

Cathepsin S as a target in gastric cancer

Cathepsin S (Cat S) is a protein expressed in some epithelial cells, which appears to be associated with cancer metastasis and recurrence. The abnormal expression of Cat S has been reported to be associated with the progression of certain types of gastrointestinal neoplasms, including gastric cancer (GC). There is a need to identify novel biomarkers and therapeutic targets associated with the growth, invasion and migration of GC cells, in order to develop non-invasive diagnostic and prognostic procedures and design new therapeutic approaches. The aim of the present study was to assess the association between Cat S and oncogenic processes implicated in the development of GC, focusing on the diagnostic and therapeutic potential of this molecule in GC. A search was conducted through the PubMed and Cochrane Central Register of Controlled Trials electronic databases for relevant literature published between 2003 and 2018, using the mesh terms 'cathepsin S' and 'cancer' and 'gastric cancer'.