Objective To evaluate the gastric microbiome in patients with chronic superficial gastritis (CSG) and intestinal metaplasia (IM) and investigate the influence of Helicobacter pylori (H. pylori) on the gastric microbiome. Methods Gastric mucosa tissue samples were collected from 54 patients with CSG and IM, and the patients were classified into the following four groups based on the state of H. pylori infection and histology: H. pylori-negative CSG (n=24), H. pylori-positive CSG (n=14), H. pylori-negative IM (n=11), and H. pylori-positive IM (n=5). The gastric microbiome was analyzed by 16S rRNA gene sequencing. Results H. pylori strongly influenced the bacterial abundance and diversity regardless of CSG and IM. In H. pylori-positive subjects, the bacterial abundance and diversity were significantly lower than in H. pylori-negative subjects. The H. pylori-negative groups had similar bacterial composition and bacterial abundance. The H. pylori-positive groups also had similar bacterial composition but different bacterial relative abundance. The relative abundance of Neisseria, Streptococcus, Rothia, and Veillonella were richer in the I-HP group than in G-HP group, especially Neisseria (t=175.1, P<0.001). Conclusions The gastric microbial abundance and diversity are lower in H. pylori- infected patients regardless of CSG and IM. Compared to H. pylori-positive CSG group and H. pylori-positive IM, the relative abundance of Neisseria, Streptococcus, Rothia, and Veillonella is higher in H. pylori-positive patients with IM than in H. pylori-positive patients with CSG, especially Neisseria.
Gastric Mucosa/microbiology* ; Gastritis, Atrophic/microbiology* ; Gastrointestinal Microbiome/genetics* ; Helicobacter Infections/microbiology* ; Helicobacter pylori/genetics* ; Humans ; Metaplasia ; RNA, Ribosomal, 16S/genetics* ; Stomach Neoplasms

BACKGROUND/AIMS: This study was aimed to investigate the polymorphism of interleukin-1beta(IL-1B) and IL-1 receptor antagonist (IL-1RN) gene and the relationship between genotypes and development of gastric adenocarcinoma in Korean, and to investigate the role of Helicobactor pylori (H. pylori) infection. METHODS: The study population comprised of 258 patients with gastric adenocarcinoma. They were classified according to Lauren's classification and the status of H. pylori infection. Genomic DNA was extracted from the gastric tissue. As a control, genomic DNA from peripheral lymphocyte of 100 healthy individuals was used. The amplified products of -511 bp and -31 bp fragments in the IL-1B by PCR were digested by restriction enzyme and separated for RFLP. Variable number tandem repeats were amplified and subjected to RFLP of IL-1RN. RESULTS: There was no significant difference in the genotype of IL-1B-511T and IL-1B-31C between the adenocarcinoma group and the control group. IL-1RN allele 1 homozygote in the intestinal type showed high frequency of 91.7% (p=0.007). In the H. pylori-positive group of the adenocarcinoma, the frequency of IL-1B-31C was significantly higher than that of H. pylori-negative group (p=0.045). CONCLUSIONS: The single nucleotide polymorphism of IL-1B-31C may contribute to the development of the gastric adenocarcinoma in the H. pylori-positive population.
Adenocarcinoma/*genetics/microbiology ; Aged ; English Abstract ; Female ; Helicobacter Infections/complications ; Helicobacter pylori ; Humans ; Interleukin-1/*genetics ; Male ; Middle Aged ; *Polymorphism, Single Nucleotide ; Stomach Neoplasms/*genetics/microbiology

OBJECTIVETo study the distribution of IL-10 gene polymorphisms in patients with gastroduodenal diseases in Hubei Han population and their association with helicobacter pylori (Hp) infection.

METHODSSix hundred and five patients with gastroduodenal diseases (220 gastric cancer, 196 chronic gastritis and 189 gastroduodenal ulcer) and 624 healthy controls were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for IL-10 -1082, -819, -592 gene polymorphisms. Hp infection status was determined by ELISA.

RESULTS(1) There was significant difference of IL-10 -1082 AG+GG genotypes between gastric cancer group and gastric cancer-free and healthy control groups (P<0.05). (2) There was no significant difference of IL-10 -592 and IL-10 -819 gene polymorphisms among gastric cancer, gastric cancer-free and healthy control groups (P>0.05). (3) The frequency of IL-10 -1082 AG+GG genotypes in the Hp positive gastric cancer patients was significantly higher than that of control groups (P<0.05).

CONCLUSIONS(1) Genotypes AG+GG of IL-10 -1082 were associated with gastric cancer in Hubei Han population. (2) The IL-10 -1082 AG+GG genotypes were associated with Hp infection in patients with gastric cancer.

Adult ; Aged ; Case-Control Studies ; China ; ethnology ; Duodenal Diseases ; ethnology ; genetics ; microbiology ; Female ; Genetic Association Studies ; Genotype ; Helicobacter Infections ; ethnology ; genetics ; microbiology ; Humans ; Interleukin-10 ; genetics ; Male ; Middle Aged ; Polymorphism, Genetic ; Risk Factors ; Stomach Neoplasms ; ethnology ; genetics ; microbiology

Intestinal metaplasia (IM) has been regarded as a premalignant condition. However, the pathogenesis of IM is not fully understood. The aim of this study was to evaluate the role of CDX1 and CDX2 in the formation of IM and the progression to dysplasia and gastric cancer (GC). A total of 270 subjects included 90 with GC, dysplasia and age- and sex-matched controls. Real-time PCR (RT-PCR) was performed with body specimens for CDX1 and CDX2. The expression of CDX2 was significantly higher in H. pylori positive group than H. pylori negative group (P = 0.045). CDX1 and CDX2 expression increased proportional to the IM grade of the body (P < 0.001). CDX2 expression was significantly higher in incomplete type of IM than in complete type (P = 0.045). The expression of CDX1 in dysplasia group was significantly higher than in the control group (P = 0.001); in addition, CDX1 and CDX2 in cancer group was significantly higher than control group (P < 0.001, and P < 0.001, respectively). Aberrant expression of CDX1 and CDX2 correlated with H. pylori infection and grade of IM in the body. Furthermore, the results suggest that CDX1 and CDX2 play a role in the progression to GC and dysplasia.
Aged ; Female ; Helicobacter Infections/complications/microbiology ; Helicobacter pylori/isolation & purification ; Homeodomain Proteins/*genetics/metabolism ; Humans ; Intestinal Diseases/*genetics/microbiology/pathology ; Male ; Metaplasia/pathology ; Middle Aged ; Polymerase Chain Reaction ; Precancerous Conditions/metabolism/pathology ; Stomach Neoplasms/etiology/*genetics/microbiology

Epidemiological data including our studies demonstrated the association between Helicobacter pylori (H. pylori) infection and gastric cancer. However, this significant clinical outcome happens only in a small portion of infected person. This suggests that other contributors including host genetic and environmental factors might be involved in the disease process. Studies on the association between virulent strains of H. pylori and clinical outcomes failed to show significant results in Korea. Cytokine gene polymorphism such as interleukin-1 (IL-1) has been thought to play a role in gastric carcinogenesis. Our studies showed the controversial role of IL-1, TNF-A, IL-10 and IL-2 gene polymorphisms in the development of gastric cancer in Korea. Chronic infection and inflammation leading to tumorigenesis are mediated in part through the recognition of various stimuli by toll-like receptors (TLRs). Our studies on the polymorphisms of TLR4 and TLR2 showed no mutant form in Koreans. These discrepancies might reflect the genetic differences between Caucasians and Koreans or might be due to prevalent genetic polymorphisms with masked effect in gastric carcinogenesis in Koreans. As other candidate risk factors, there are constant or inconsistent results on the effect of dietary intake in gastric cancer. There are numerous similar risk for gastric carcinogenesis with different risk ratio including environmental factors in Caucasians and Koreans. Under the background of prevalent H. pylori infection and genetic polymorphisms, environmental factors including diet may potentiate their role in gastric carcinogenesis in Koreans.
Cytokines/genetics ; Diet ; Genetic Predisposition to Disease ; Helicobacter Infections/*complications/microbiology ; *Helicobacter pylori/pathogenicity ; Humans ; Korea ; *Polymorphism, Genetic ; Risk Factors ; Stomach Neoplasms/*etiology/genetics/microbiology ; Toll-Like Receptor 4/genetics ; Tumor Markers, Biological ; Virulence Factors

OBJECTIVETo investigate the effect of Helicobacter pylori-encoded CagA on biological behavior of gastric adenocarcinoma AGS cells.

METHODSWith experiment-control system of the wild-type CagA positive strain and isogenic CagA negative mutant strain of Helicobacter pyroli (Hp) were used as control and experimental groups, respectively. The cell contact, migration and invasion were examined by light and electron microscopy and invasion assay.

RESULTSThe AGS cells infected by Hp strain with positive wild-type CagA showed more severely changed tight junction, wider intercellular space, loss of cell contacts, and higher migrating and invasive ability.

CONCLUSIONHp CagA may lead to loss of cell contacting and higher migrating and invading ability of gastic cells, and accelerates the malignant progress of tumor.

Adenocarcinoma ; microbiology ; pathology ; ultrastructure ; Antigens, Bacterial ; genetics ; Bacterial Proteins ; genetics ; Cell Line, Tumor ; Cell Movement ; Extracellular Space ; Helicobacter pylori ; genetics ; pathogenicity ; Humans ; Intercellular Junctions ; ultrastructure ; Mutation ; Stomach Neoplasms ; microbiology ; pathology ; ultrastructure

OBJECTIVETo clarify the role of these cyclins in human gastric cancer.

METHODS38 gastric cancer patients, 29 first degree relatives of gastric cancer patients, as well as 18 healthy subjects were included. The mRNA expression of cyclins D1, D2, D3 and E in gastric biopsies was evaluated by RT-PCR analysis using specific primers. Histomorphological features such as intestinal metaplasia, atrophy, H. pylori infection and severity of gastritis were determined by the updated Sydney System.

RESULTSSignificant mRNA overexpression was found for cyclins D2, D3 and E compared with healthy normal specimen, but cyclin D1 expression was not different between tumor and normal tissues. In addition, cyclin D2 and D3 overexpression was significantly more frequent in first degree relatives than in healthy controls (P < 0.05). Among the various pathological findings, the overexpression of cyclins D2 and E was associated with intestinal metaplasia, and the overexpression of cyclin D3 was associated with intestinal metaplasia as well as atrophy. The overexpression of cyclins D2 and D3 was significantly correlated with H. pylori infection. No correlation was observed between the overexpression of cyclin D1 and any pathological variables.

CONCLUSIONThe overexpression of cyclins D2, D3 and E is a frequent event in patients with gastric cancer and their first degree relatives and may be an early event in gastric carcinogenesis.

Adult ; Aged ; Aged, 80 and over ; Cyclin D1 ; genetics ; Cyclin D2 ; Cyclin D3 ; Cyclin E ; genetics ; Cyclins ; genetics ; Family Health ; Gastritis ; genetics ; Gene Expression Regulation, Neoplastic ; Helicobacter Infections ; genetics ; microbiology ; Helicobacter pylori ; growth & development ; Humans ; Middle Aged ; RNA, Messenger ; genetics ; metabolism ; Stomach ; metabolism ; microbiology ; pathology ; Stomach Neoplasms ; genetics ; pathology

Gastric cancer is one of the most common malignancies and a leading cause of cancer mortality worldwide. The pathogenesis mechanisms of gastric cancer are still not fully clear. Inactivation of tumor suppressor genes and activation of oncogenes caused by genetic and epigenetic alterations are known to play significant roles in carcinogenesis. Accumulating evidence has shown that epigenetic silencing of the tumor suppressor genes, particularly caused by hypermethylation of CpG islands in promoters, is critical to carcinogenesis and metastasis. Here, we review the recent progress in the study of methylations of tumor suppressor genes involved in the pathogenesis of gastric cancer. We also briefly describe the mechanisms that induce tumor suppressor gene methylation and the status of translating these molecular mechanisms into clinical applications.
Apoptosis ; Cell Adhesion ; Cell Cycle ; CpG Islands ; genetics ; DNA Methylation ; DNA Repair ; Epigenesis, Genetic ; Genes, Tumor Suppressor ; Helicobacter Infections ; genetics ; Helicobacter pylori ; Humans ; Neoplasm Invasiveness ; Promoter Regions, Genetic ; genetics ; Stomach Neoplasms ; genetics ; metabolism ; microbiology ; pathology ; Tumor Suppressor Proteins ; genetics ; metabolism

Gastric cancer is the second leading cause of cancer-related mortality and the fourth most common cancer globally. There are, however, distinct differences in incidence rates in different geographic regions. While the incidence rate of gastric cancer has been falling, that of gastric cardia cancers is reportedly on the rise in some regions. Helicobacter pylori (H. pylori) infection is a major risk factor of non-cardia gastric cancer, and data has emerged concerning the role of H. pylori eradication for primary prevention of gastric cancer. Dietary, lifestyle and metabolic factors have also been implicated. Although addressing these other factors may contribute to health, the actual impact in terms of cancer prevention is unclear. Once irreversible histological changes have occurred, endoscopic surveillance would be necessary. A molecular classification system offers hope for molecularly tailored, personalised therapies for gastric cancer, which may improve the prognosis for patients.
Female ; Global Health ; Helicobacter Infections ; complications ; prevention & control ; Helicobacter pylori ; Humans ; Incidence ; Male ; Obesity ; complications ; Risk Factors ; Stomach Neoplasms ; epidemiology ; genetics ; microbiology ; prevention & control

Cancer is a collection of complex diseases in which cell proliferation and apoptosis are dysregulated due to the acquisition of genetic changes in cancer cells. These genetic changes, combined with the interrelated physiologic adaptations of neo-angiogenesis, recruitment of stromal support tissues, and suppression of immune recognition, are measurable characteristics in tumor gene expression profiles and biochemical pathways. These measures can lead to identification of disease drivers and, ultimately, can be used to assign therapy. With advances in RNA sequencing technologies, the ability to simultaneously measure all genetic and gene expression changes with a single technology is now possible. The ability to create a comprehensive catalog of genotypic and phenotypic changes in a collection of histologically similar but otherwise distinct tumors should allow for a more precise positioning of existing targeted therapies and identification of new targets for intervention.
Animals ; Asian Continental Ancestry Group ; Cell Transformation, Neoplastic ; genetics ; Disease Models, Animal ; Drug Discovery ; Genes, Tumor Suppressor ; Helicobacter pylori ; Humans ; Neoplasms ; genetics ; Oncogenes ; Signal Transduction ; Stomach Neoplasms ; genetics ; microbiology ; therapy