Development Of Gastric Adenocarcinoma Research Articles

Abstract 1730: Unraveling the oncogenic potential of KDM2A with gastric organoids

Abstract Background: Gastric adenocarcinoma (GAC), prevalent and often lethal, imposes a serious global health challenge. Therefore, it is critical to identify novel oncogenes (drivers) that can be therapeutically targeted. Of epigenetic modifications, histone lysine methylation is a hallmark of epigenetic and transcriptional regulation of gene expression. Therefore, investigating the involvement of histone methylation modifiers in GAC is paramount to gaining a comprehensive understanding of the disease but also to discover novel targets. Our analysis of the GAC genome indicates that these epigenetic modifiers are amplified in GAC. Objective and Hypothesis: The overall objective is to define the oncogenic role of KDM2A in GAC pathogenesis and progression. The central hypothesis is that KDM2A promotes GAC by upregulating the expression of oncogenic proteins via the activation of epigenomic signatures/pathways.KDM2A (FBXL11) is a histone lysine demethylase that demethylates H3K36me2 and represses target genes involved in various biological processes, including cell proliferation, DNA damage repair, and stem cell maintenance. Previously, we reported that KDM2A was necessary for the tumorigenic and metastatic capabilities of non-small lung cancer cells through transcriptionally repressing the expression of DUSP3 and HDAC3, which led to activation of ERK signaling and upregulation of cell cycle-associated genes. Results: Our analysis of the GAC genome indicates that KDM2A is one of the top demethylases frequently amplified and overexpressed (14%). In addition, KDM2A expression was significantly higher in GAC samples than in normal tissues, and high expression of KDM2A was associated with poor survival in GAC patients. To examine the effect of KDM2A knockdown on characteristics of GAC, we used gastric organoids generated from KDM2Aflox/flox mouse stomach. We expressed wild-type (Flag-KDM2A) and catalytic mutant (Flag-KDM2A-mut) in these organoids. Ectopic expression of KDM2A wild-type, but not mutant, increased the proliferation of organoids. We showed that KDM2A knockdown decreased the proliferation and invasion of two GAC cells, GA0518 and AGS. In addition, we determine the effect of overexpression of KDM2A on cell proliferation by comparing the control organoids to KDM2A overexpressed using IHC staining of Ki-67 (a proliferation marker) and other activated oncogenic signaling PI3KCA/mTOR/AKT, EGFR. We showed that GA5018 cells were very sensitive to the KDM2A inhibitor (daminozide) alone and in combination with erlotinib (EGFRi inhibitor) and RAD001 (RAD1 mTOR inhibitor). Significance and Innovation: In contrast to advances in cellular signaling pathways in GAC pathogenesis, how GAC development is epigenetically regulated remains largely unknown. Our results from using organoids indicate that KDM2A is an oncoprotein. Citation Format: Shilpa S. Dhar, Calena Brown, Constantin Zod, Jaffer A. Ajani, Min Gyu Lee. Unraveling the oncogenic potential of KDM2A with gastric organoids [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1730.

Helicobacter pylori CagA protein induces gastric cancer stem cell-like properties through the Akt/FOXO3a axis.

The presence of Helicobacter pylori (H. pylori) infection poses a substantial risk for the development of gastric adenocarcinoma. The primary mechanism through which H. pylori exerts its bacterial virulence is the cytotoxin CagA. This cytotoxin has the potential to induce inter-epithelial mesenchymal transition, proliferation, metastasis, and the acquisition of stem cell-like properties in gastric cancer (GC) cells infected with CagA-positive H. pylori. Cancer stem cells (CSCs) represent a distinct population of cells capable of self-renewal and generating heterogeneous tumor cells. Despite evidence showing that CagA can induce CSCs-like characteristics in GC cells, the precise mechanism through which CagA triggers the development of GC stem cells (GCSCs) remains uncertain. This study reveals that CagA-positive GC cells infected with H. pylori exhibit CSCs-like properties, such as heightened expression of CD44, a specific surface marker for CSCs, and increased ability to form tumor spheroids. Furthermore, we have observed that H. pylori activates the PI3K/Akt signaling pathway in a CagA-dependent manner, and our findings suggest that this activation is associated with the CSCs-like characteristics induced by H. pylori. The cytotoxin CagA, which is released during H. pylori infection, triggers the activation of the PI3K/Akt signaling pathway in a CagA-dependent manner. Additionally, CagA inhibits the transcription of FOXO3a and relocates it from the nucleus to the cytoplasm by activating the PI3K/Akt pathway. Furthermore, the regulatory function of the Akt/FOXO3a axis in the transformation of GC cells into a stemness state was successfully demonstrated.

Microsatellite instability in precancerous changes in the gastric mucosa

Microsatellite instability is a widely known and sought after tumor marker. Among other things, its prevalence and role in the development of gastric adenocarcinoma are being studied. However, the profile of microsatellite instability during precancerous changes in the gastric mucosa (atrophy, intestinal metaplasia, epithelial dysplasia) remains insufficiently studied. The purpose of this literature review is to assess the possibility of using microsatellite instability status as a diagnostic and predictive marker of precancerous changes and lesions of the gastric mucosa. A systematic review of publications in the PubMed database was conducted using a search query based on the combination of the terms “microsatellite instability” (“MSI”), “stomach/gastric cancer/adenocarcinoma”, “stomach/gastric dysplasia/intraepithelial neoplasia”, “stomach/gastric precancerous lesions” for the period from 1997 to 2023. Review articles were excluded from the search results. The systematic review included 11 relevant publications. Despite the lack of a uniform methodology and diversity in the study groups, all publications demonstrated an increase in the level of microsatellite instability in the range from normal (unchanged) gastric mucosa and/or its precancerous changes to gastric cancer: among precancerous changes in the gastric mucosa, the most common subject of study was intestinal metaplasia, where levels of microsatellite instability ranged from 0 to 53.3%, while its levels in gastric cancer ranged from 32.6 to 76.7%. The results of the studies included in the review may indicate a possible predictive role of microsatellite instability in precancerous changes in the gastric mucosa in relation to the risk of developing cancer.

Bioinformatics analysis identifies coagulation factor II receptor as a potential biomarker in stomach adenocarcinoma

Coagulation factor 2 thrombin receptor (F2R), a member of the G protein-coupled receptor family, plays an important role in regulating blood clotting through protein hydrolytic cleavage mediated receptor activation. However, the underlying biological mechanisms by which F2R affects the development of gastric adenocarcinoma are not fully understood. This study aimed to systematically analyze the role of F2R in gastric adenocarcinoma. Stomach adenocarcinoma (STAD)-related gene microarray data and corresponding clinicopathological information were downloaded from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Differential expression genes (DEGs) associated with F2R were analyzed using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), gene set enrichment analysis (GSEA), and protein–protein interaction (PPI) networks. F2R mRNA expression data were utilized to estimate stromal cell and immune cell scores in gastric cancer tissue samples, including stromal score, immune score, and ESTIMATE score, derived from single-sample enrichment studies. Analysis of TCGA and GEO databases revealed significantly higher F2R expression in STAD tissues compared to normal tissues. Patients with high F2R expression had shorter survival times than those with low F2R expression. F2R expression was significantly correlated with tumor (T) stage, node (N) stage, histological grade and pathological stage. Enrichment analysis of F2R-related genes showed that GO terms were mainly related to circulation-mediated human immune response, immunoglobulin, cell recognition and phagocytosis. KEGG analysis indicated associations to extracellular matrix (ECM) receptor interactions, neuroactive ligand-receptor interactions, the phosphoinositide-3-kinase-protein kinase B/Akt (PI3K-AKT) signaling pathway, the Wnt signaling pathway and the transforming growth factor-beta (TGF-β) signaling pathway. GSEA revealed connections to DNA replication, the Janus kinase/signal transducers and activators of transcription (JAK-STAT) signaling pathway, the mitogen-activated protein kinase (MAPK) signaling pathway and oxidative phosphorylation. Drug sensitivity analysis demonstrated positive correlations between F2R and several drugs, including BEZ235, CGP-60474, Dasatinib, HG-6-64-1, Aazopanib, Rapamycin, Sunitinib and TGX221, while negative correlation with CP724714, FH535, GSK1904529A, JNK-9L, LY317615, pyrimidine, rTRAIL and Vinorelbine. Knocking down F2R in GC cell lines resulted in slowed proliferation, migration, and invasion. All statistical analyses were performed using R software (version 4.2.1) and GraphPad Prism 9.0. p < 0.05 was considered statistically significant. In conclusion, this study underscores the significance of F2R as a potential biomarker in gastric adenocarcinoma, shedding light on its molecular mechanisms in tumorigenesis. F2R holds promise for aiding in the diagnosis, prognosis, and targeted therapy of STAD.

CEACAM5 and TROP2 define metaplastic and dysplastic transitions in human antral gastric precancerous lesions and tumors.

Mucosal gastric atrophy and intestinal metaplasia (IM) increase the risk for the development of gastric cancer (GC) as they represent a field for development of dysplasia and intestinal-type gastric adenocarcinoma. We have investigated the expression of two dysplasia markers, CEACAM5 and TROP2, in human antral IM and gastric tumors to assess their potential as molecular markers. In the normal antral mucosa, weak CEACAM5 and TROP2 expression was only observed in the foveolar epithelium, while inflamed antrum exhibited increased expression of both markers. Complete IM exhibited weak CEACAM5 expression at the apical surface, but no basolateral TROP2 expression. On the other hand, incomplete IM demonstrated high levels of both CEACAM5 and TROP2 expression. Notably, incomplete IM with dysplastic morphology (dysplastic incomplete IM) exhibited higher levels of CEACAM5 and TROP2 expression compared to incomplete IM without dysplastic features (simple incomplete IM). In addition, dysplastic incomplete IM showed diminished SOX2 and elevated CDX2 expression compared to simple incomplete IM. CEACAM5 and TROP2 positivity in incomplete IM was similar to that of gastric adenomas and GC. Significant association was found between CEACAM5 and TROP2 positivity and histology of GC. These findings support the concept that incomplete IM is more likely associated with GC development. Overall, our study provides evidence of the heterogeneity of gastric IM and the distinct expression profiles of CEACAM5 and TROP2 in dysplastic incomplete IM. Our findings support the potential use of CEACAM5 and TROP2 as molecular markers for identifying individuals with a higher risk of GC development in the context of incomplete IM.

FOXD2 regulations IQGAP3 mediated Ca2+ signaling pathway to facilitate gastric adenocarcinoma cell promotion.

As a transcriptional factor, the Forkhead box (FOX) gene family is closely connected with apoptosis, proliferation, and other cellular processes. FOXD2, as one descendant of the FOX gene family, has been mentioned in many articles to show a high expression in several cancers. However, whether FOXD2 has a connection with gastric adenocarcinoma remains an unanswered question. Expression of FOXD2 and IQGAP3 in gastric adenocarcinoma was evaluated by bioinformatics analysis, which was further detected by real-time quantitative PCR (qRT-PCR) and western blot. The downstream target genes of FOXD2 were also mined by bioinformatics analysis. Pathway enrichment analysis was then performed on the target genes. Chromatin immunoprecipitation assay (ChIP) and dual-luciferase reporter assay were conducted to validate the regulatory relationship between FOXD2 and its downstream target gene IQGAP3. Methyl thiazolyl tetrazolium assay (MTT), combined with cell colony formation assay, was employed to assess the effect of FOXD2 and IQGAP3 on the proliferation of gastric adenocarcinoma cells. Intracytoplasmic Ca2+ concentration was measured by Fluo-3 fluorescence staining. FOXD2 showed a high expression in gastric adenocarcinoma tissues and cells, and FOXD2 silencing considerably attenuated gastric adenocarcinoma cell proliferation. IQGAP3, a downstream target gene of FOXD2, had a positive connection with the expression of FOXD2. The binding relationship between FOXD2 and the promoter region of IQGAP3 was further verified by ChIP and dual-luciferase reporter assays. The results of cell function experiments indicated that FOXD2 could promote gastric adenocarcinoma cell proliferation by transcriptionally activating IQGAP3 to induce an increase in intracellular Ca2+ level. This study confirmed that FOXD2 increased intracellular Ca2+ level through transcriptional activation of IQGAP3, which in turn propelled the proliferation of gastric adenocarcinoma cells, revealing the considerable significance of FOXD2 in the development of gastric adenocarcinoma.

Role of the CagY antenna projection in Helicobacter pylori Cag type IV secretion system activity.

Helicobacter pylori strains containing the cag pathogenicity island (PAI) are associated with the development of gastric adenocarcinoma and peptic ulcer disease. The cag PAI encodes a secreted effector protein (CagA) and a type IV secretion system (Cag T4SS). Cag T4SS activity is required for the delivery of CagA and non-protein substrates into host cells. The Cag T4SS outer membrane core complex (OMCC) contains a channel-like domain formed by helix-loop-helix elements (antenna projections, AP) from 14 copies of the CagY protein (a VirB10 ortholog). Similar VirB10 antenna regions are present in T4SS OMCCs from multiple bacterial species and are predicted to span the outer membrane. In this study, we investigated the role of the CagY antenna region in Cag T4SS OMCC assembly and Cag T4SS function. An H. pylori mutant strain with deletion of the entire CagY AP (∆AP) retained the capacity to produce CagY and assemble an OMCC, but it lacked T4SS activity (CagA translocation and IL-8 induction in AGS gastric epithelial cells). In contrast, a mutant strain with Gly-Ser substitutions in the unstructured CagY AP loop retained Cag T4SS activity. Mutants containing CagY AP loops with shortened lengths were defective in CagA translocation and exhibited reduced IL-8-inducing activity compared to control strains. These data indicate that the CagY AP region is required for Cag T4SS activity and that Cag T4SS activity can be modulated by altering the length of the CagY AP unstructured loop.

High-Salt Diet Exacerbates H. pylori Infection and Increases Gastric Cancer Risks.

Gastric cancer ranks as the fifth-leading contributor to global cancer incidence and the fourth-highest in terms of cancer-related mortality. Helicobacter pylori (H. pylori) infection leads to inflammation and ulceration, atrophic and chronic gastritis, and eventually, increases the risk of developing gastric adenocarcinoma. In this paper, we delve into the combined impact of a high-salt diet (HSD) and concurrent H. pylori infection, which act as predisposing factors for gastric malignancy. A multitude of mechanisms come into play, fostering the development of gastric adenocarcinoma due to the synergy between an HSD and H. pylori colonization. These encompass the disruption of mucosal barriers, cellular integrity, modulation of H. pylori gene expression, oxidative stress induction, and provocation of inflammatory responses. On the whole, gastric cancer patients were reported to have a higher median sodium intake with respect to healthy controls. H. pylori infection constitutes an additional risk factor, with a particular impact on the population with the highest daily sodium intake. Consequently, drawing from epidemiological discoveries, substantial evidence suggests that diminishing salt intake and employing antibacterial therapeutics could potentially lower the susceptibility to gastric cancer among individuals.

Clinical significance of CD155 expression and correlation with cellular components of tumor microenvironment in gastric adenocarcinoma.

CD155 is recently emerging as a promising target in malignancies. However, the relationship between CD155 expression and tumor microenvironment (TME) cell infiltration in gastric adenocarcinoma (GAC) has rarely been clarified. We measured CD155 expression in specimens of gastric precancerous disease and GAC by immunohistochemistry. The association of CD155 expression with GAC progression and cells infiltration in TME was evaluated through 268 GAC tissues and public dataset analysis. We showed that the expression of CD155 was positively correlated with the pathological development of gastric precancerous disease (r = 0.521, P < 0.0001). GAC patients with high CD155 expression had a poorer overall survival (P = 0.033). Moreover, CD155 expression correlated with aggressive clinicopathological features including tumor volume, tumor stage, lymph node involvement, and cell proliferation (P <0.05). Remarkably, CD155 expression positively related to the infiltration of CD68+ macrophages in TME (P = 0.011). Meanwhile, the positive correlation was observed between CD155 and CD31 (P = 0.026). In addition, patients with high CD155 expression combined with low CD3, CD4, CD8, IL-17, IFN-γ or CD19 expression as well as those with high CD155 and α-SMA expression showed significantly worse overall survival (P < 0.05). CD155 may play a pivotal role in the development of GAC through both immunological and non-immunological mechanisms and be expected to become a novel target of immunotherapy in GAC patients.

METTL3 regulates N6-methyladenosine modification of ANGPTL3 mRNA and potentiates malignant progression of stomach adenocarcinoma

BackgroundN6-methyladenosine (m6A) is associated with mammalian mRNA biogenesis, decay, translation and metabolism, and also contributes greatly to gastrointestinal tumor formation and development. Therefore, the specific mechanisms and signaling pathways mediated by methyltransferase-like 3 (METTL3), which catalyzes the formation of m6A chemical labeling in stomach adenocarcinoma (STAD), are still worth exploring.MethodsQuantitative real-time PCR (qRT-PCR) was constructed to detect the expression of METTL3 in gastric cancer cell lines and patient tissues. The biological function of METTL3 was investigated in vitro/in vivo by Cell Counting Kit-8, colony formation assay, Transwell assay and nude mouse tumorigenesis assay. Based on the LinkedOmics database, the genes co-expressed with METTL3 in the TCGA STAD cohort were analyzed to clarify the downstream targets of METTL3. Methylated RNA immunoprecipitation-qPCR (MeRIP-qPCR) and RNA stability analysis were employed to explore the mechanism of METTL3 in gastric cancer progression.ResultsWe analyzed TCGA data and found that METTL3 was frequently elevated in STAD, and demonstrated that METTL3 was present at high levels in clinical STAD tissues and cells. High METTL3 expression was more likely to have advanced TNM tumors and distant metastasis. On the other hand, METTL3 silencing effectively impeded the higher oncogenic capacity of AGS and HGC27 cells in vivo and in vitro, as reflected by slowed cell growth and diminished migration and invasion capacities. Continued mining of the TCGA dataset identified the co-expression of angiopoietin-like 3 (ANGPTL3) and METTL3 in STAD. Lower level of ANGPTL3 was related to increased level of METTL3 in STAD samples and shorter survival times in STAD patients. ANGPTL3 enrichment limited the growth and metastasis of STAD cells. Besides, ANGPTL3 mRNA levels could be decreased by METTL3-dominated m6A modifications, a result derived from a combination of MeRIP-qPCR and RNA half-life experiments. Importantly, the inhibitory effect of METTL3 silencing on cancer could be reversed to some extent by ANGPTL3 inhibition.ConclusionsOverall, our findings suggested that METTL3 functioned an oncogenic role in STAD by reducing ANGPTL3 expression in an m6A-dependent manner. The discovery of the METTL3-ANGPTL3 axis and its effect on STAD tumor growth will contribute to further studies on the mechanisms of gastric adenocarcinoma development.

Computer analysis of abnormal proliferation and transformation cells in gastric mucosa and its clinical significance

ABSTRACT To investigate the image computer analysis of abnormally proliferating transformed cells of gastric mucosa and its clinical significance. The pathological pictures of gastric adenomatous polyp cells, abnormally proliferating altered cells, and tubular adenocarcinoma cells in the stomach mucosa were assessed by image computer method on a total of 96 gastroscopic biopsy and ESD resection specimens. The data of cytoplasmic area, nuclear area, nuclear-cytoplasmic ratio, nuclear factor and N-heterotypic index of gastric adenomatous polyps, abnormal proliferative transformation and gastric intramucosal tubular adenocarcinoma were collected, and the mean, standard deviation and variance were calculated respectively. Standard Error, Maximum, Minimum Parameters and Statistical Structure. There were substantial discrepancies between gastric mucosal gastric adenomatous polyp cells and gastric mucosal abnormally proliferating transformed cells, according to the five data in the abnormal cells in the stomach mucosal proliferation area (p < 0.01); There was no significant difference between cells (p > 0.05). Computer analysis of cell images can provide quantitative values for the pathological diagnosis of gastric adenomatous polyp cells, abnormally proliferating transformed cells and tubular adenocarcinoma cells in the gastric mucosa, especially the degree of atypical proliferation. The monitoring of abnormally proliferated and transformed cells in gastric mucosa is of great significance for clinicians to accurately treat and track cell transformation, and to control the occurrence and development of gastric adenocarcinoma.

Risk factors in the development of gastric adenocarcinoma in the general population: A cross-sectional study of the Wuwei Cohort.

Several risk factors have been identified for the development of gastric adenocarcinoma (GAC), where the control group was usually a healthy population. However, it is unclear at what stage known risk factor exert their influence toward the progression to cancer. Based on the Wuwei Cohort, we enrolled 1,739 patients with chronic non-atrophic gastritis (no-CAG), 3,409 patients with chronic atrophic gastritis (CAG), 1,757 patients with intestinal metaplasia (IM), 2,239 patients with low-grade dysplasia (LGD), and 182 patients with high-grade dysplasia (HGD) or GAC to assess the risk factors between each two consecutive stages from no-CAG to GAC/HGD using adjusted logistic regression. We found that different groups of risk factors were associated with different stages. Age, occupation of farmer, low annual family income, Helicobacter pylori (H. pylori) infection, drinking, eating hot food, histories of gastritis and peptic ulcer were associated with the development of CAG. Age, illiteracy, H. pylori infection, smoking, eating hot food, eating quickly, and histories of gastritis and gallbladder diseases were associated with the progression to IM from CAG. Male, occupation of farmer and history of peptic ulcer were associated with the development of LGD from IM. Age, male and polyp history appeared to be risk factors associated with the development of GAC/HGD from LGD. In conclusion, it seems that most risk factors function more as a set of switches that initiated the GAC carcinogenesis. H. Pylori eradication and control of other risk factors should be conducted before IM to decrease the incidence of GAC.

Penetrance of Gastric Adenocarcinoma Susceptibility Genes: A Systematic Review.

Gastric adenocarcinoma (GAC) is the fifth most common cancer in the world, and the presence of germline pathogenic variants has been linked with approximately 5% of gastric cancer diagnoses. Multiple GAC susceptibility genes have been identified, but information regarding the risk associated with pathogenic variants in these genes remains obscure. We conducted a systematic review of existing studies reporting the penetrance of GAC susceptibility genes. A structured search query was devised to identify GAC-related papers indexed in MEDLINE/PubMed. A semi-automated natural language processing algorithm was applied to identify penetrance papers for inclusion. Original studies reporting the penetrance of GAC were included and the full-text articles were independently reviewed. Summary statistics, effect estimates, and precision parameters from these studies were compiled into a table using a predetermined format to ensure consistency. Forty-five studies were identified reporting the penetrance of GAC among patients harboring mutations in 13 different genes: APC, ATM, BRCA1, BRCA2, CDH1, CHEK2, MLH1, MSH2, MSH6, PMS2, MUTYH-Monoallelic, NBN, and STK11. Our systematic review highlights the importance of testing for germline pathogenic variants in patients before the development of GAC. Management of patients who harbor a pathogenic mutation is multifactorial, and clinicians should consider cancer risk for each applicable gene-cancer association throughout the screening and management process. The scarcity of studies we found investigating the risk of GAC among patients with pathogenic variants in GAC susceptibility genes highlights the need for more investigations that focus on producing robust risk estimates for gene-cancer associations.

Clarithromycin-, and metronidazole-resistant Helicobacter pylori isolated from raw and ready-to-eat meat in Mansoura, Egypt

Helicobacter pylori (H. pylori), classified as a class-I carcinogen, is one of the leading medical pathogens of global concern associated mainly with the development of gastric adenocarcinomas and gastric mucosa-associated lymphoid tissue lymphomas; nevertheless, its prevalence in food especially meat and meat products is not fully covered. Additionally, the resistance of H. pylori towards clarithromycin is increasing worldwide and consider the leading cause of H. pylori treatment failure. Thus, the present study was designed to determine the prevalence, molecular characterization, and antimicrobial resistance profiles of clarithromycin-, and metronidazole-resistant H. pylori isolated from raw and ready-to-eat meat samples retailed in Mansoura city, Egypt. Among the 250 samples tested, H. pylori were molecularly confirmed in 40.8 % (49/120) of raw meat products and in 29.2 % (38/130) of ready-to-eat meat products. Precisely, 53.3 % (32/60), 56.7 % (17/30), 40 % (8/20), 55 % (11/20), 60 % (12/20), 13.3 % (4/30), and 15 % (3/20) of raw ground beef, beef burger, beef burger sandwiches, beef shawarma sandwiches, beef kofta sandwiches, beef luncheon, and beef sausage sandwiches, respectively were positive for H. pylori. Of the 204 biochemically-identified H. pylori isolates, 53.9 % (110/204) were molecularly confirmed by PCR through the detection of glmM, cagA, or vacA genes, which were detected at an incidence of 95.5 % (105/110), 77.3 % (85/110), and 20.9 % (23/110) among the isolates, respectively. The antimicrobial sensitivity testing revealed that all of the 110 (100 %) molecularly-confirmed H. pylori isolates were multidrug-resistant (MDR; resistant to four or more antibiotics). Interestingly, 100 % and 61.8 % of H. pylori isolated from raw and ready-to-eat meat were resistant to metronidazole and clarithromycin, respectively which consider alarming results as metronidazole and clarithromycin are the mainstay antibiotics in the treatment of H. pylori infections. Additionally, 94.5 %, 94.5 %, 24.5 %, 23.6 %, and 13.6 % of isolates were resistant to vancomycin, sulphamethoxazole-trimethoprim, imipenem, levofloxacin, and nitrofurantoin, respectively. The widespread contamination of examined raw and ready-to-eat meat product samples with MDR H. pylori isolates could constitute a tremendous public health hazard. Further studies concerning the prevalence and possible methods of elimination of H. pylori in different food categories distributed in the various provinces in Egypt as well as in other countries is required for a better understanding the H. pylori as an emerging foodborne pathogen.

The Efficacy of Cancer Immunotherapies Is Compromised by Helicobacter pylori Infection.

Helicobacter pylori infects the gastric mucosa of a large number of humans. Although asymptomatic in the vast majority of cases, H pylori infection can lead to the development of peptic ulcers gastric adenocarcinoma and mucosa-associated lymphoid tissue (MALT) lymphoma. Using a variety of mechanisms, H pylori locally suppresses the function of the host immune system to establish chronic infection. Systemic immunomodulation has been observed in both clinical and pre-clinical studies, which have demonstrated that H pylori infection is associated with reduced incidence of inflammatory diseases, such as asthma and Crohn’s disease. The introduction of immunotherapies in the arsenal of anti-cancer drugs has revealed a new facet of H pylori-induced immune suppression. In this review, we will describe the intimate interactions between H pylori and its host, and formulate hypothtyeses describing the detrimental impact of H pylori infection on the efficacy of cancer immunotherapies.

The TNF-Alpha Inducing Protein is Associated With Gastric Inflammation and Hyperplasia in a Murine Model of Helicobacter pylori Infection.

Helicobacter pylori (H. pylori) is a Gram-negative bacterium that colonizes the human stomach leading to the development of chronic gastritis, peptic ulcers and gastric adenocarcinoma. A combination of host, environment and bacterial virulence factors contribute to disease development. The H. pylori TNFα inducing protein (Tipɑ) is a virulence factor shown to induce multiple pro-inflammatory cytokines in addition to TNFα in vitro. The goal of the present study was to elucidate the role of Tipα in promoting inflammation in vivo and to identify the molecular pathways associated with Tipα associated virulence. Mice were infected with wild-type Sydney strain (SS1) or a tipα mutant (Δtipα) for 1 month and 4 months. We also completed a second 4 months infection including a 1:1 SS1 to Δtipα co-infected group in addition to SS1 and Δtipα infected groups. The expression of TNFα, and KC were significantly higher in the SS1 infected group compared to both uninfected control (naïve) and Δtipα groups. Mice infected with Tipα expressing SS1 induced more severe histological gastritis and developed hyperplasia compared to Δtipα infected mice. Microarray analysis of gastric epithelial cells co-cultured with recombinant Tipα (rTipα) demonstrates up-regulation of the NFκB pathway. This data suggest Tipα plays an important role in H. pylori induced inflammation.

Analysis of the nervus vagus effect on gastric adenocarcinoma development

Analysis of the nervus vagus effect on gastric adenocarcinoma development

Two Distinct Etiologies of Gastric Cancer: Infection and Autoimmunity.

Gastric cancer is a leading cause of mortality worldwide. The risk of developing gastric adenocarcinoma, which comprises >90% of gastric cancers, is multifactorial, but most associated with Helicobacter pylori infection. Autoimmune gastritis is a chronic autoinflammatory syndrome where self-reactive immune cells are activated by gastric epithelial cell autoantigens. This cause of gastritis is more so associated with the development of neuroendocrine tumors. However, in both autoimmune and infection-induced gastritis, high risk metaplastic lesions develop within the gastric mucosa. This warrants concern for carcinogenesis in both inflammatory settings. There are many similarities and differences in disease progression between these two etiologies of chronic gastritis. Both diseases have an increased risk of gastric adenocarcinoma development, but each have their own unique comorbidities. Autoimmune gastritis is a primary cause of pernicious anemia, whereas chronic infection typically causes gastrointestinal ulceration. Both immune responses are driven by T cells, primarily CD4+ T cells of the IFN-γ producing, Th1 phenotype. Neutrophilic infiltrates help clear H. pylori infection, but neutrophils are not necessarily recruited in the autoimmune setting. There have also been hypotheses that infection with H. pylori initiates autoimmune gastritis, but the literature is far from definitive with evidence of infection-independent autoimmune gastric disease. Gastric cancer incidence is increasing among young women in the United States, a population at higher risk of developing autoimmune disease, and H. pylori infection rates are falling. Therefore, a better understanding of these two chronic inflammatory diseases is needed to identify their roles in initiating gastric cancer.

Epstein-Barr Virus associated gastric carcinoma in a patient with germline STAT3 gain-of-function mutation

Abstract Introduction/Objective Signal transducer and activator of transcription 3 (STAT3) is a transcription factor involved in inflammation, proliferation, differentiation and survival. STAT3 gain-of-function (GoF) disorders are characterized by immune dysregulation and present with polyendocrinopathy, enteropathy, X-linked syndrome (IPEX)- or autoimmune lymphoproliferative syndrome (ALPS)-like features. While patients with STAT-3 GoF are known to have an increased risk for hematologic malignancies, neither solid tumors nor an increased risk for EBV-associated disorders have been described. We report the first case of an EBV-associated solid organ tumor in a patient with STAT-3 GoF. Methods/Case Report A 21-year-old male with germline mutation in STAT3 (variant p. M329K) presented with early satiety, abdominal pain and worsening of chronic anemia. Serology showed high EBV DNA PCR levels. Endoscopy showed multiple nodular lesions in the stomach, which were biopsied to reveal EBV-associated high-grade dysplasia and intramucosal adenocarcinoma. Initiation of chemotherapy with a poor response led to a total gastrectomy. Gross examination of the specimen showed a 7.9 x 6.5 x 1.8 cm tan-brown, exophytic mass in the posterior wall of the body and antrum, involving the greater curvature. Histology revealed an adenocarcinoma with tubulovillous morphology extending into the lamina propria, without invasion into the muscularis mucosa or submucosa. EBER in-situ hybridization was diffusely positive in the tumor cells. The background mucosa showed severe chronic active and atrophic gastritis with intestinal metaplasia and low-grade dysplasia. All the seventy examined lymph nodes were negative for metastasis. Helicobacter-like organisms were not seen. Results (if a Case Study enter NA) NA Conclusion This is the first report of a solid tumor in a patient with STAT3 GoF mutation. The role of the patient’s underlying immune dysregulation disorder in the development of EBV-associated gastric adenocarcinoma is unclear and warrants further investigation. The case also highlights the importance of a close clinical follow-up in this patient population, as unexpected malignancies can develop at younger ages.

Kimura–Takemoto Classification: A Tool to Predict Gastric Intestinal Metaplasia Progression to Advanced Gastric Neoplasia

Gastric cancer is a leading cause of morbidity and mortality worldwide. Gastric intestinal metaplasia (GIM) has been described as a key histologic step in the development of gastric adenocarcinoma. However, not all people with GIM develop malignancy. We studied the factors associated with progression to dysplasia and advanced gastric neoplasia (aGN) in patients with baseline GIM. Retrospective cohort analysis of patients with baseline GIM and subsequent endoscopic evaluation at Cleveland Clinic Florida and Ohio Main Campus between 2005 and 2017. Demographic and exposure risk factors, as well as Kimura-Takemoto classification (KTc), were used as variables for hazards ratio (HR) and Kaplan-Meier survival-free analysis for aGN and any form of dysplasia progression. There were 708 patients identified with GIM; 29 patients (4.1%) progressed to any degree of dysplasia. From these, LGD was present in 12 cases (1.7%), HGD in 4 cases (0.6%), and gastric cancer in 13 cases (1.8%), for a total of 17 aGN cases. KTc was associated with dysplasia and aGN progression (p < 0.001), and no cases progressed if KTc findings were absent. Open-type KTc was associated with aGN (HR 6.36, p < 0.001) and any dysplasia progression (HR 13.34, p < 0.001) compared to closed-type or absent KTc features. No other factors were associated with aGN or dysplasia progression. Open-type KTc was also associated with shorter cancer survival-free progression. Patients with baseline GIM present a higher progression risk to aGN, dysplasia, or cancer if concomitant KTc findings are present, particularly an open-type KTc pattern.