Serum Helicobacter pylori NapA antibody as a potential biomarker for gastric cancer

Helicobacter pylori-related serum indicators: Cutting-edge advances to enhance the efficacy of gastric cancer screening

Helicobacter pylori (H. pylori) infection induces pathological changes via chronic inflammation and virulence factors, thereby increasing the risk of gastric cancer development. Compared with invasive examination methods, H. pylori-related serum indicators are cost-effective and valuable for the early detection of gastric cancer (GC); however, large-scale clinical validation and sufficient understanding of the specific molecular mechanisms involved are lacking. Therefore, a comprehensive review and analysis of recent advances in this field is necessary. In this review, we systematically analyze the relationship between H. pylori and GC and discuss the application of new molecular biomarkers in GC screening. We also summarize the screening potential and application of anti-H. pylori immunoglobulin G and virulence factor-related serum antibodies for identifying GC risk. These indicators provide early warning of infection and enhance screening accuracy. Additionally, we discuss the potential combination of multiple screening indicators for the comprehensive analysis and development of emerging testing methods to improve the accuracy and efficiency of GC screening. Although this review may lack sufficient evidence due to limitations in existing studies, including small sample sizes, regional variations, and inconsistent testing methods, it contributes to advancing personalized precision medicine in high-risk populations and developing GC screening strategies.

Fn-Dps, a novel virulence factor of Fusobacterium nucleatum, disrupts erythrocytes and promotes metastasis in colorectal cancer

Fusobacterium nucleatum (Fn) is a critical colorectal cancer (CRC)-associated bacterium. DNA hunger/stationary phase protective proteins (Dps) are bacterial ferritins that protect DNA from oxidative stress. However, little is known about the regulatory roles of Fn-Dps towards host cellular functions. Here, we identified Fn-Dps from the culture supernatant of Fn by mass spectrometry, and prepared the recombinant of Fn-Dps protein. We show a novel virulence protein of Fn, Fn-Dps, which lyses and disrupts erythrocytes by the competition for iron acquisition. Also, Fn-Dps facilitates intracellular survival of Fn in macrophages by upregulating the expression of the chemokine CCL2/CCL7. In addition, Fn-Dps can elicit a strong humoral immune response, and mucosal immunization with Fn-Dps conferred protection against Fn in the intestinal tract. Moreover, a high level of anti-Fn-Dps antibody was prevalent in populations, and elevated anti-Fn-Dps antibody levels were observed in CRC patients. Furthermore, Fn-Dps promotes the migration of CRC cells via the CCL2/CCL7-induced epithelial-mesenchymal transition (EMT) and promotes CRC metastasis in vivo.

Helicobacter pylori virulence dupA gene: risk factor or protective factor?

Helicobacter pylori is the etiological agent of chronic gastritis, peptic ulcer, and gastric cancer. The duodenal ulcer-promoting gene dupA, which is located in the plasticity region of the H. pylori genome, is homologous to the virB gene which encodes a type IV secretion protein in Agrobacterium tumefaciens. Studies have shown associations between H. pylori dupA-positive strains and gastroduodenal diseases. However, whether dupA acts as a risk factor or protective factor in these diseases remains unclear. Therefore, in this study, we aimed to verify the presence of the dupA gene in infectious H. pylori strains in the Brazilian mid-west and to investigate its association with the clinical outcomes of patients with dyspepsia. Additionally, the phylogenetic origin of the strains was determined. Gastric biopsies from 117 patients with dyspepsia were analyzed using histological and molecular techniques. The hpx gene (16S rRNA) was used to screen for H. pylori infection, and positive samples were then subjected to dupA gene detection and sequencing. The estimated prevalence of H. pylori infection was 64.1%, with the dupA gene being detected in a high proportion of infectious strains (70.7%). Furthermore, a risk analysis revealed that for women, a dupA-positive H. pylori infection increased the chance of developing gastritis by twofold. The partial dupA sequences from isolated infectious strains in this work are similar to those of strains isolated in westerns countries. This study provides useful insights for understanding the role of the H. pylori dupA gene in disease development.

FRA-1 suppresses apoptosis of Helicobacter pylori infected MGC-803 cells

Previous research has demonstrated a correlation between elevated expression of Fos-related antigen 1 (FRA-1) and malignancies. Nevertheless, the role of FRA-1 in Helicobacter pylori infected gastric cancer cells remains vague. Our study aims to investigate whether FRA-1 plays a role in the apoptosis of MGC-803 induced by H. pylori and possible mechanisms. MGC-803 cells were used in vitro to establish a cell model of H. pylori infection. After stimulation with H. pylori, the expression of FRA-1 was increased in MGC-803 cells. H. pylori infection promoted the apoptosis of MGC-803 cells, and led to cell cycle arrest and increased oxidative stress levels. Furthermore, the knockdown of FRA-1 reinforced these changes. H. pylori decreased the expression of Bcl2, Caspase3 and Caspase9, while increased the level of BAX, Cleaved-Caspase3 and Cleaved-Caspase9; in addition, it led to the decrease of major proteins in Ras/Erk and PI3K/AKT signaling pathway. As expected, these changes were augmented by FRA-1 knockdown. Our results demonstrated that high expression of FRA-1 induced by H. pylori suppresses apoptosis in MGC-803 cells which may be regulated by oxidative stress and cycle arrest through caspase family, Ras/Erk and PI3K/AKT signaling pathway.

Serum Helicobacter pylori FliD antibody and the risk of gastric cancer

FliD and CagA are important virulence factors of H. pylori. We aimed to evaluate the screening values of FliD and CagA for gastric cancer (GC). Serum samples were obtained from 232 cases and 266 controls in a case-control study. Unconditional multivariate logistic regression with odds ratios (ORs) and 95% confidence intervals (CIs) was used to analyze the relationships between FliD, CagA and GC. The sensitivities, specificities and receiver operating characteristic (ROC) curves were calculated. Finally, the combined screening values of FliD, FlaA, NapA and CagA were assessed based on discriminant analysis. In all subjects, the associations of FliD and CagA with GC were evident with ORs (95% CIs) of 7.6 (4.7-12.3) and 2.5 (1.6-3.8), respectively (*p<0.001). The areas under ROC curves (AUCs) for FliD and CagA were 0.800 and 0.653, respectively. The AUC for the combination of FliD, FlaA and NapA was 0.915, which represented an increase of 0.115 over that of FliD alone (*p<0.001). These findings indicate that the FliD antibody is associated with GC and could exhibit high validity as a biomarker in screening for GC patients. The combination of FliD, FlaA and NapA improved the screening validity.

Combination of OipA, BabA, and SabA as candidate biomarkers for predicting Helicobacter pylori-related gastric cancer

Helicobacter pylori (H. pylori ) infection is a major cause of chronic gastritis and is highly related to duodenal ulcer (DU) and gastric cancer (GC). To identify H. pylori-related GC biomarkers with high seropositivity in GC patients, differences in levels of protein expression between H. pylori from GC and DU patients were analyzed by isobaric tag for relative and absolute quantitation (iTRAQ). In total, 99 proteins showed increased expression (>1.5-fold) in GC patients compared to DU patients, and 40 of these proteins were categorized by KEGG pathway. The four human disease-related adhesin identified, AlpA, OipA, BabA, and SabA, were potential GC-related antigens, with a higher seropositivity in GC patients (n = 76) than in non-GC patients (n = 100). Discrimination between GC and non-GC patients was improved using multiple antigens, with an odds ratio of 9.16 (95% CI, 2.99-28.07; p < 0.0001) for three antigens recognized. The optimized combination of OipA, BabA, and SabA gave a 77.3% correct prediction rate. A GC-related protein microarray was further developed using these antigens. The combination of OipA, BabA, and SabA showed significant improvement in the diagnostic accuracy and the protein microarray containing above antigens should provide a rapid and convenient diagnosis of H. pylori-associated GC.

Serum Antibodies against Helicobacter pylori Neutrophil Activating Protein in Carriers of IL-4 C-590T Genetic Polymorphism Amplify the Risk of Gastritis and Gastric Cancer

BACKGROUND

Gastric cancer arises, mainly, on an inflammatory background. Helicobacter pylori neutrophil activating (HP-NAP) protein functions as a potent pro-inflammatory mediator. Similarly, IL-4 plays a critical role in the inflammation pathway, the levels of which are altered by C to T transition at position -590 in its promoter region. Here, we have aimed to assess the risk of gastritis and gastric cancer in the co-presence of these two inflammation modulating mediators.

METHODS

Gastritis (n=58) and gastric cancer (n=31) patients were evaluated and compared with H. pylori-positive asymptomatic controls (n=46), for serum antibodies against recombinant HP-NAP and IL-4 C-590T single nucleotide polymorphism using immunoblotting and PCR-RFLP, respectively. Multivariable logistic regression, adjusting for age, gender and ethnicity, was used for data analysis.

RESULTS

In terms of susceptibility to gastritis, seropositivity to HP-NAP projected a risk impact of 4.62 fold (OR=4.62, 95% CI=1.50-14.22), which when present in IL-4 -590 T carriers augmented the risk up to 9.7 fold (OR=9.70, 95% CI=2.06-45.69). A similar pattern, but of a stronger magnitude, occurred for the risk of gastric cancer, which was estimated at 9.07 fold (OR=9.07, 95% CI=1.99-42.0) for HP-NAP-seropositive subjects and was drastically amplified (OR=33.64, 95% CI=2.06-548.68), when double-positive (HP-NAP seropositive/IL-4 -590 T carrier) subjects were examined against double negatives (HP-NAP seronegative/IL-4 -590 CC).

CONCLUSION

Our preliminary data indicate that serum antibodies against HP-NAP represent a state of risk, which is further exacerbated in IL-4 -590 T carriers. These biomarkers, if validated in larger prospective studies, can be used to screen for gastric cancer susceptibility.

Novel class of Bi(iii) hydroxamato complexes: synthesis, urease inhibitory activity and activity against H. pylori

Reaction of Bi(NO3)3 with benzohydroxamic acid (Bha) and salicylhydroxamic acid (Sha) gives the novel Bi(iii) complexes [Bi2(Bha-1H)2(μ-Bha-1H)2(η(2)-NO3)2] () and [Bi6(CH3OH)2(η(1)-NO3)2(η(2)-NO3)(OH2)2(Sha-1H)12](NO3)2 (). X-ray crystal structure of reveals two hydroxamato coordination modes; bidentate bridging (O, O') and bidentate non-bridging (O, O') and of reveals one coordination mode; bidentate bridging (O, O'). , specifically designed to and demonstrated to inhibit the activity of urease, exhibits excellent antibacterial activity against three strains of Helicobacter pylori with MIC ≥ 16 μg mL(-1).

Aberrant methylation of PCDH10 and RASSF1A genes in blood samples for non-invasive diagnosis and prognostic assessment of gastric cancer

Background. Assessment of DNA methylation of specific genes is one approach to the diagnosis of cancer worldwide. Early stage detection is necessary to reduce the mortality rate of cancers, including those occurring in the stomach. For this purpose, tumor cells in circulating blood offer promising candidates for non-invasive diagnosis. Transcriptional inactivation of tumor suppressor genes, like PCDH10 and RASSF1A, by methylation is associated with progression of gastric cancer, and such methylation can therefore be utilized as a biomarker.

Methods. The present research was conducted to evaluate DNA methylation in these two genes using blood samples of gastric cancer cases. Clinicopathological data were also analyzed and cumulative survival rates generated for comparison.

Results. High frequencies of PCDH10 and RASSF1A methylations in the gastric cancer group were noted (94.1% and 83.2%, respectively, as compared to 2.97% and 5.45% in 202 matched controls). Most patients (53.4%) were in severe stage of the disease, with a median survival time of 8.4 months after diagnosis. Likewise, the patients with metastases, or RASSF1A and PCDH10 methylations, had median survival times of 7.3, 7.8, and 8.4 months, respectively. A Kaplan–Meier analysis showed that cumulative survival was significantly lower in those cases positive for methylation of RASSF1A than in their negative counterparts. Similarly, whereas almost 100% of patients positive for PCDH10 methylation had died after five years, none of the negative cases died over this period. Notably, the methylations of RASSF1A and PCDH10 were found to be higher in the late-stage patients and were also significantly correlated with metastasis and histology.

Conclusions.PCDH10 and RASSF1A methylations in blood samples can serve as potential non-invasive diagnostic indicators in blood for gastric cancer. In addition to RASSF1A methylation, tumor stage proved to be a major prognostic factor in terms of survival rates.

Diagnosis of Helicobacter pylori: Changes towards the Future

Since the first evidence demonstrating the dramatically high incidence of H. pylori infection and the subsequent medical challenges it incurs, health management of H. pylori infection has been a high priority for health authorities worldwide. Despite a decreasing rate of infection in western countries, prevalence of H. pylori infection in developing and in some industrial countries is still very high. Whereas treatment and vaccination against H. pylori is a contemporary issue in medical communities, selective treatment and prior high-throughput screening of the subject population is a major concern of health organizations. So far, diagnostic tests are either elaborative and require relatively advanced medical care infrastructure or they do not fulfill the criteria recommended by the Maastricht IV/Florence consensus report. In this review, in light of recent scientific studies, we highlight current and possible future approaches for the diagnosis of H. pylori. We point out that novel non-invasive tests may not only cover the requirements of gold standard methods in H. pylori detection but also offer the potential for risk stratification of infection in a high throughput manner.