Tomiyasu Arisawa

The Influence of Polymorphisms of Interleukin-17A and Interleukin-17F Genes on the Susceptibility to Ulcerative Colitis

We investigated the association between ulcerative colitis (UC) and polymorphisms of IL-17A (rs2275913, G-197A) and IL-17F (rs763780, 7488T/C) genes. We employed the multiplex PCR-SSCP method to detect gene polymorphisms. Both the numbers of -197A (IL-17A) and 7488T (IL-17F) alleles were significantly correlated to the development of UC. The frequencies of -197A/A and 7488T/T genotypes in the UC group were significantly higher than those in the non-UC group. An adjusted analysis revealed that -197A and 7488T alleles were independent risk factors for the developing UC. In addition, both polymorphisms were significantly associated with the pancolitis phenotype. Furthermore, -197A allele was significantly correlated to the chronic relapsing phenotype and -197A/A homozygote was more frequent in steroid-dependent cases, whereas 7488T allele was correlated with the chronic continuous phenotype. Our results provided the first evidence that -197A (IL-17A) and 7488T (IL-17F) alleles may influence the susceptibility to and pathophysiological features of UC independently.

Toll-like receptor 2 -196 to 174del polymorphism influences the susceptibility of Japanese people to gastric cancer.

Toll like receptors (TLR) play important roles in the signaling of many pathogen‐related molecules and endogenous proteins associated with immune activation. The –196 to –174del polymorphism affects the TLR2 gene and alters its promoter activity. We investigated the influence of the TLR2–196 to –174del polymorphism on the occurrence of non‐cardiac gastric cancer (NCGC) in a Japanese population. The study was carried out with 289 patients with NCGC, 309 non‐cancer patients with abdominal discomfort and 146 healthy controls. The –196 to –174del TLR2 polymorphism was investigated using the allele‐specific polymerase chain reaction method in all of the subjects. The –196 to –174del/del genotype of TLR2 showed a significantly higher frequency in NCGC patients than in healthy controls (adjusted odds ratio [OR] = 6.06; 95% confidence interval [CI] = 1.86–19.72). Similarly, the frequency of the –196 to –174del/del genotype was significantly higher among NCGC patients than in non‐cancer patients (adjusted OR = 2.02; 95% CI = 1.22–3.34). The same genotype was associated with an increased risk of both intestinal (OR = 2.00, 95% CI = 1.12–3.60) and diffuse‐type (OR = 2.05; 95% CI = 1.11–3.79) histopathology. There were no significant associations between TLR2 genotypes and tumor stage and anatomical location. Our data suggest that the –196 to –174del/del genotype of TLR2 may increase the risk of gastric cancer in the Japanese population. (Cancer Sci 2007; 98: 1790–1794)

Evidence-based clinical practice guidelines for functional dyspepsia

General interest in functional gastrointestinal disorders is increasing among Japanese doctors as well as patients. This increase can be attributed to a number of factors, including recent increased interest in quality of life and advances in our understanding of the pathophysiology of gastrointestinal disease. Japan recently became the world’s first country to list “functional dyspepsia” as a disease name for national insurance billing purposes. However, recognition and understanding of functional dyspepsia (FD) remain poor, and no standard treatment strategy has yet been established. Accordingly, the Japanese Society of Gastroenterology (JSGE) developed an evidence-based clinical practice guideline for FD, consisting of five sections: concept, definition, and epidemiology; pathophysiology; diagnosis; treatment; and prognosis and complications. This article summarizes the Japanese guideline, with particular focus on the treatment section. Once a patient is diagnosed with FD, the doctor should carefully explain the pathophysiology and benign nature of this condition, establish a good doctor–patient relationship, and then provide advice for daily living (diet and lifestyle modifications, explanations, and reassurance). The proposed pharmacological treatment is divided into two steps: initial treatment including an acid inhibitory drug (H2RA or PPI) or prokinetics, (strong recommendation); second-line treatment including anxiolytics, antidepressants, and Japanese traditional medicine (weak recommendation). H. pylori eradication, strongly recommended with a high evidence level, is positioned separately from other treatment flows. Conditions that do not respond to these treatment regimens are regarded as refractory FD. Patients will be further examined for other organic disorders or will be referred to specialists using other approaches such as psychosomatic treatment.

Selenoprotein S (SEPS1) gene -105G>A promoter polymorphism influences the susceptibility to gastric cancer in the Japanese population

BackgroundInflammation is a key factor in the process of carcinogenesis from chronic gastritis induced by Helicobacter pylori. Selenoprotein S (SEPS1) is involved in the control of the inflammatory response in the endoplasmic reticulum (ER). Recently the -105G>A polymorphism in the promoter of SEPS1 was shown to increase pro-inflammatory cytokine expression. We examined the association between this polymorphism and the risk of gastric cancer.MethodsWe took stomach biopsies during endoscopies of 268 Japanese gastric cancer patients (193 males and 75 females, average age 65.3), and 306 control patients (184 males and 122 females, average age 62.7) and extracted the DNA from the biopsy specimens. All subjects provided written informed consent. For the genotyping of the SEPS1 promoter polymorphism at position -105G>A, PCR-RFLP methods were used and the PCR products were digested with PspGI.Logistic-regression analysis was used to estimate odds ratios (OR) and 95% confidence intervals (CI), adjusting for age, sex, and H. pylori infection status.ResultsAmong cases, the distribution of genotypes was as follows: 88.4% were GG, 11.2% were GA, and 0.4% were AA. Among controls, the distribution was as follows: 92.5% were GG, 7.2% were GA, and 0.3% were AA. Among males, carrying the A allele was associated with an increased odds of gastric cancer, compared with the GG genotype (OR: 2.0, 95% CI 1.0–4.1, p = 0.07). Compared with the GG genotype, carrying the A allele was significantly associated with increased risks of intestinal type gastric cancer (OR: 2.0, 95%CI 1.0–3.9, p < 0.05) as well as of gastric cancer located in the middle third of the stomach (OR: 2.0, 95%CI 1.0–3.9, p < 0.05).ConclusionThe -105G>A promoter polymorphism of SEPS1 was associated with the intestinal type of gastric cancer. This polymorphism may influence the inflammatory conditions of gastric mucosa. Larger population-based studies are needed for clarifying the relation between inflammatory responses and SEPS1 polymorphism.

Homozygous 825T Allele of the GNB3 Protein Influences the Susceptibility of Japanese to Dyspepsia

The role of genetics in the susceptibility to functional dyspepsia (FD) is not well established. Recently, two different associations were reported between FD and G-protein beta3 (GNB3) subunit gene polymorphism. We aim to clarify the association between GNB3 protein C825T polymorphism and dyspepsia in the Japanese population. Eight-nine dyspeptics and 94 nondyspeptic subjects enrolled in this study. All subjects underwent gastroscopy and patients with significant upper gastrointestinal findings were excluded. Other diseases were also excluded by face-to-face history and physical examination. GNB3 protein C825T polymorphisms were determined by polymerase chain reaction-restriction fragment-length polymorphism. H. pylori infection status was examined by histology or antibody against H. pylori. Nonsignificant correlation was found between GNB3 protein homozygous 825T and unexplained dyspepsia (ORxa0=xa01.65, 95% CI: 0.87–3.13). However, among H. pylori-negative subjects, homozygous GNB3 protein 825T significantly increased the risk of dyspepsia (16.7% versus 40.5%; CC versus TT; ORxa0=xa05.10, 95% CI: 1.21–21.43, CC versus others; ORxa0=xa03.40, 95% CI: 1.16–9.93, respectively). This significant association remained after logistic regression analysis with adjustment for sex and age (CC versus TT; ORxa0=xa05.73, 95% CI: 1.27–25.82, CC versus others; ORxa0=xa03.08, 95% CI: 1.02–9.25). No significant correlation was found between GNB3 polymorphism and any dyspeptic symptoms. Our data suggest that the homozygous 825T allele of GNB3 protein is associated with dyspepsia in the H. pylori-negative Japanese population. The role of genetics in the development of dyspepsia needs further evaluation.

A Polymorphism of microRNA 27a Genome Region Is Associated With the Development of Gastric Mucosal Atrophy in Japanese Male Subjects

Noncoding microRNAs regulate the expression of various mRNAs. We attempted to clarify the relationship between miR-27a genome polymorphism and chronic gastritis. The study was performed in 179 patients with no evidence of gastric malignancy. The severity of histologic chronic gastritis was classified according to the updated Sydney system. The frequency of miR-27a G allele was 34.6%. Although the frequencies of miR-27a G allele were increased in subjects with peptic ulcer or severe mucosal atrophy, no significant differences were seen. The miR-27a polymorphism showed an interaction with gender in relation to gastric mucosal atrophy (P=.090). In only male subjects, the miR-27a polymorphism was associated with the gastric mucosal atrophy (P=.039) and both atrophy and metaplasia scores in G/G group were significantly higher than those in the other groups. The miR-27a genome region polymorphism may be an important definitive factor to develop the gastric mucosal atrophy in Japanese male subjects.

Risk prediction of gastric cancer by analysis of aberrant DNA methylation in non-neoplastic gastric epithelium.

Background: Aberrant DNA methylation is one of the major events in carcinogenesis. Promoter DNA methylation is also present in various non-neoplastic tissues including gastric epithelium as age-related phenomenon, suggesting that it occurs early in the process of tumorigenesis. Aim: We aimed to clarify the relationship of aberrant DNA methylation in non-neoplastic gastric epithelia with the risk of gastric cancer, Helicobactor pylori infection, and the degree of H. pylori-induced gastritis. Methods: 89 patients enrolled in this study. The status of aberrant DNA methylation was compared in two groups of patients: 43 cases with gastric cancer (mean age 65.9 years [29–91], F:M = 0.30, intestinal type [n = 25], diffuse type [n = 18]) and 46 age- and sex-matched patients without gastric cancer (peptic ulcer diseases [n = 11], gastritis [n = 35]) as a control group. Genomic DNA was extracted directly from non-neoplastic epithelia of antral biopsies obtained by endoscopy. The promoter methylation status of the p14 and p21 genes was determined by methylation-specific-polymerase chain reaction (MSP). The promoter methylation status of the p16 gene was quantified by digital densitographic analysis following MSP. The degree of gastritis in the antrum was assessed according to the updated Sydney system. The PG I/II ratio was calculated based on the data of serum PG I and PG II levels measured by radioimmunoassay. Results: In all 89 subjects, CpG island methylation was found in 25.8% for p14, 52.8% for p16, 1.1% for p21. Among non-cancer patients, the methylation frequency of the p14 gene was significantly higher in H. pylori-positive than in H. pylori-negative patients (38.5 vs. 10.0%, p = 0.03). The mean (± SD) methylation levels of the p16 gene in non-neoplastic gastric epithelium was significantly higher in gastric cancer cases both in all patients and in H. pylori-positive patients (0.45 ± 0.31 vs. 0.20 ± 0.17; p = 0.019, 0.45 ± 0.31 vs. 0.20 ± 0.17; p = 0.016, respectively). The methylation level of the p16 gene was also associated with the presence of intestinal-type gastric cancer (p = 0.017). The methylation level of the p16 gene was significantly higher in patients with intestinal metaplasia (IM) than those without (p = 0.04). Furthermore, the methylation level of the p16 gene was correlated with lower PG l/ll ratio (p = 0.04). The methylation of the p21gene was found in only 1 patient with gastric cancer. Conclusions: Our data suggest that promoter of the p14 gene may be one of the specific regions whose methylation is closely associated with H. pylori infection. Methylation levels of the p16 gene seem to be accumulated in the progression of gastric mucosal atrophy and IM, and thus may be associated with the presence of gastric cancer especially for intestinal-type histopathology.

Genetic polymorphisms of CD14 and Toll-like receptor-2 (TLR2) in patients with ulcerative colitis

Background and Aim:u2002 Ulcerative colitis (UC) is a multifactorial disease resulting from a complex interaction of genetic and environmental factors. Identifying genetic variants that alter the innate immune response is highly relevant to understanding the pathogenesis of UC. The aim of this study was to investigate the association between CD14 and Toll‐like receptor‐2 (TLR2) genetic polymorphisms and chronic UC in Japanese patients.

Promoter methylation of protease-activated receptor (PAR2) is associated with severe clinical phenotypes of ulcerative colitis (UC).

Tryptase acting at protease-activated receptor 2 (PAR2) contributes to the pathogenesis of Inflammatory bowel diseases (IBDs). DNA methylation has been shown to be an important mechanism in gene silencing. We attempted to clarify the relationship between the promoter methylation of PAR2 and ulcerative colitis (UC). 84 UC patients enrolled in the study. UC patients were classified by disease behavior, severity and extent of disease. For rectal inflammatory mucosal specimens from all the patients, and normal terminal ileum from 23 patients, promoter methylation of PAR2 gene was quantified by digital densitographic analysis following to methylation-specific polymerase chain reaction (MSP). The mean methylation levels of the PAR2 gene in all 84 subjects was 38.4xa0±xa019.6%. Although mean methylation levels in rectal inflammatory mucosa, and paired normal terminal ileum did not vary, methylation levels of PAR2 gene was significantly higher in total colitis than rectal colitis (total colitis vs. rectal colitis; 42.9xa0±xa019.6% vs. 34.5xa0±xa018.9%, Pxa0=xa00.046). The higher methylation levels were also associated with Steroid-dependent (Pxa0=xa00.002) and refractory (Pxa0=xa00.007) UC. Our data suggest that PAR2 methylation status in rectal mucosa correlates with more severe disease phenotypes of UC.

ABSENCE OF COMMON POLYMORPHISMS OF TOLL LIKE RECEPTOR 4 (TLR4): ASP299GLY, THR399ILE IN PATIENTS WITH GASTRODUODENAL DISEASES IN JAPAN

Host genetic factors may play a key role in determining the long-term outcome of the Helicobacter pylori (H. pylori) infection. Toll-like receptor 4 (TLR4) mediated recognition of lipo-polysaccharide (LPS) is required for efficient recognition of gram-negative bacterial infections. The aim of this study is to investigate the effects of common polymorphisms of TLR4 Asp299Gly, Thr399Ile in patients with gastroduodenal diseases in Japanese population. The study was performed in 149 gastric cancer (GC) cases (mean age 64.0 ± 12.4, M:F = 109:40) and 94 patients without evidence of GC (mean age 64.1 ± 12.3, M:F = 65:25) as the control group. TLR4 Asp299Gly, Thr399Ile were determined by Polymerase chain reaction-length of polymorphisms (PCR-RFLP) in all the patients. Asp299Gly, Thr399Ile were not detected in all 243 patients enrolled in this study. In conclusion, our data suggest that TLR4 Asp299Gly, Thr399Ile are very rare in Japanese population and thus they may not be a important factor in determining the outcome of H. pylori infected individuals in Japan.