Association between cyclin D1 (CCND1) polymorphism and gastric cancer risk in Japanese population

BACKGROUND/AIMS

A complex interaction of genetic and environmental factors is relevant in gastric carcinogenesis. Cyclin D1 (CCND1) is known to regulate function in G1 arrest and therefore, may play an important role in carcinogenesis. The present study aimed to clarify the effect of G870A polymorphism of the CCND1 gene on the risk of gastric cancer (GC) in a Japanese population.

METHODOLOGY

Restriction fragment length polymorphism analysis was performed for polymorphisms at 870GA in the CCND1 gene in 392 GC and 359 cancer-free subjects including 203 H. pylori positive gastritis and 156 H. pylori negative healthy stomach

RESULTS

Non significant association was found between CCND1 G870A genotypes and risk of GC when compared to that of all non-cancer subjects (AA vs. GG+GA: OR = 1.13, 95% CI = 0.81-1.58, A carrier vs. GG: OR = 1.13, 95% CI = 0.81-1.56), healthy stomach(AA vs. GG+GA: OR = 1.27, 95% CI = 0.81-2.00, A carrier vs. GG: OR = 1.13, 95% CI = 0.8-1.84) and gastritis. (AA vs. GG+GA: OR = 1.03, 95% CI = 0.7-1.53, p = 0.92, A carrier vs. GG: 1.06, 95% CI = 0.72-1.56, p = 0.77) No association was found between CCND1 genotypes and any of clinico-pathological features of GC.

CONCLUSION

It appears that the G870 polymorphism of CCND1 is not associated with the risk of GC in the Japanese population.

CD14 promoter-159 polymorphism is associated with reduced risk of intestinal-type gastric cancer in a Japanese population

Host genetic factors may play a key role in determining the long-term outcome of the Helicobacter pylori infection. Toll-like receptor 4 (TLR4) and CD14-mediated recognition of lipo-polysaccharide (LPS) is required for efficient recognition of gram-negative bacterial infections. We investigated the effects of common polymorphisms of TLR4 Asp299Gly, Thr399Ile, and CD14 promoter-C159T on the risk of gastric cancer including its subtypes and clinicopathologic features. We also investigated the effects of these polymorphisms on histologic degree of H. pylori-induced gastritis. 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, Peptic ulcer diseases = 43.6%, gastritis = 56.4%) as the control group. TLR4 Asp299Gly, Thr399Ile, and CD14 promoter-C159T were determined by PCR-RFLP in all the patients. Gastritis scores of non-cancerous gastric mucosa were assessed according to the updated Sydney system in H. pylori-positive subjects (n = 179). The frequencies of CD14-260 TT and T carrier were significantly lower in patents with intestinal-type gastric cancer than in controls (OR = 0.31; 95%CI = 0.12-0.78, OR = 0.38; 95%CI = 0.18-0.81, respectively). Compared to patients older than 61 years, the atrophy score in antrum was significantly lower in TT and CT patients. TLR4 Asp299Gly and Thr399Ile were not detected in all the patients. Our data suggests that CD14 promoter-159TT and T carrier were associated with a lower risk of developing gastric mucosal atrophy in H. pylori-infected patients of more than 61 years of age, and these genotypes may reduce the risk of intestinal-type gastric cancer.

Chronic nonsteroidal anti-inflammatory drug (NSAID) use suppresses multiple CpG islands hyper methylation (CIHM) of tumor suppressor genes in the human gastric mucosa

There have been reports showing a protective role of nonsteroidal anti-inflammatory drugs (NSAIDs) against gastrointestinal cancers. CpG island hyper methylation (CIHM) of tumor suppressor genes is a major event in carcinogenesis. We investigated the CIHM status of non-cancerous gastric mucosa in chronic NSAID users and non-users and assessed the effect of NSAIDs on CIHM. Gastric mucosa samples were obtained from 51 chronic NSAID users and 180 non-users. CIHM of p14(ARF), p16(INK4a), death-associated protein kinase (DAP-kinase), and E-cadherin (CDH1) genes were determined by methylation-specific PCR. CIHM high was defined as two or more CpG islands methylated. CIHM of p14, p16, CDH1, and CIHM high were lower in chronic NSAID users than in non-users (p14: non-users vs users = 32.2%vs 9.8%, P = 0.003; p16: non-users vs users = 35.0%vs 15.7%, P = 0.02; CDH1: non-users vs users = 36.1%vs 9.8%, P = 0.0009; CIHM high: non-users vs users = 44.4%vs 17.6%, P = 0.0009). NSAID use was also associated with decreased number of CIHM by anova (R = -0.32, P < 0.0001). Multivariate logistic regression analysis with adjustment for sex, age, Helicobacter pylori infection, and NSAID use revealed that NSAID use was inversely correlated with all four CIHM and CIHM high as an independent factor (p14: odds ratio [OR] = 0.17, 95% confidence interval [CI] = 0.06-0.48; p16: OR = 0.32, 95% CI = 0.14-0.75; DAP-kinase: OR = 0.45, 95% CI = 0.22-0.92; CDH1: OR = 0.18, 95% CI = 0.06-0.48; CIHM high: OR = 0.21, 95% CI = 0.09-0.49). No association was found between CIHM status and the duration or dose of NSAIDs. Chronic NSAID use suppresses CIHM in human gastric mucosa. NSAIDs may have a suppressive role against methylation-related gastric carcinogenesis.

779 TC of CCK-1 intron 1 is associated with postprandial syndrome (PDS) in Japanese male subjects

BACKGROUND/AIMS

The role of genetics in the susceptibility to functional dyspepsia (FD) is not well established. Cholecystokinin (CCK) is released from enteroendocrine cells in the duodenal mucosa after food ingestion and signals satiation through peripheral or central actions. A common polymorphisms of CCK and it's receptor gene has been shown to be associated with panic disorder and schizophrenia. It was investigated the prevalence of CCK polymorphism in dyspeptic patients in a Japanese population.

METHODOLOGY

A total of 124 dyspeptic patients, 119 non-symptomatic healthy controls participated in this study. Dyspeptic patients were also classified by Rome III criteria. T779C of Cholecystokinin (CCK)-1 intron 1, by polymerase chain reaction-restriction fragment length polymorphism. H. pylori infection status was examined by histology or antibody against H. pylori.

RESULTS

Although frequency of CCK-1 polymorphisms in overall dyspeptic patients, subgroups by Roma III criteria and non-symptomatic healthy controls did not show any significant differences, 779 T carriers significantly increased the risk of postprandial syndrome (PDS) in male subjects (53.5% vs, 84.2; OR = 4.63, 95% CI = 1.24-17.31, p = 0.018). This significant association was also remained after logistic regression analysis with adjustment for age and H. pylori infection status (OR = 4.99, 95% CI = 1.31-18.95, p = 0.018). In female and different H. pylori infection status, no significant association was observed between CCK-1 polymorphisms and dyspepsia.

CONCLUSION

Our data suggest that the 779 T carriers of CCK-1 intron 1 is associated with an increased risk of PDS in Japanese male subjects.

Effect of RANTES promoter genotype on the severity of intestinal metaplasia in Helicobacter pylori-infected Japanese subjects

BACKGROUND

A complex interaction of host genetic and environmental factors may be relevant in the development of Helicobacter pylori (H. pylori)-related gastro-duodenal diseases. RANTES is a potent chemoattractant peptide for memory T lymphocytes and eosinophils, and has been shown to be enhanced in H. pylori-infected gastric mucosa. We aimed to clarify the effect of RANTES functional promoter polymorphism on the risk of gastro-duodenal diseases in a Japanese population.

METHODS

Four hundred and eighty-three subjects, comprising 106 gastric ulcer, 52 duodenal ulcer, and 325 non-ulcer subjects, were included in this study. Restriction fragment length polymorphism (RFLP) analysis was performed for polymorphisms at -28 C/G in the RANTES gene promoter region. Gastritis scores of antral gastric mucosa were assessed according to the updated Sydney system.

RESULTS

There were no significant differences in the RANTES promoter genotype distributions among non-ulcer subjects, ulcer patients, and gastric and duodenal ulcers. However, the degree of intestinal metaplasia was significantly lower among G carriers in H. pylori-infected subjects aged 60 years or older (C/C vs. G carriers; 1.28 +/- 1.02 vs. 0.83 +/- 0.89, P = 0.0357). In addition, we also found that the same genotype held a lower risk of more severe intestinal metaplasia in H. pylori-infected female subjects (C/C vs. G carriers; 0.91 +/- 1.03 vs. 0.41 +/- 0.73, P = 0.0443).

CONCLUSION

The polymorphism of RANTES promoter is not associated with the susceptibility to peptic ulcer diseases, but the -28 G carrier is associated with a reduced risk of developing more severe intestinal metaplasia in H. pylori-positive subjects aged 60 years and older and in female subjects.

Association of polymorphism of the p22PHOX component of NADPH oxidase in gastroduodenal diseases in Japan

OBJECTIVE

Superoxide has been implicated in the pathogenesis of Helicobacter pylori-related diseases through inflammation. NADPH oxidase, a major source of superoxide generation, plays a critical role in H. pylori-related gastric inflammation. The aim of this study was to clarify the effect of the p22PHOX C242T polymorphism, an essential component of NADPH oxidase in the risk of gastroduodenal diseases, on the severity of H. pylori-induced gastritis in a Japanese population.

MATERIAL AND METHODS

The study comprised 436 patients attending the Endoscopy Center of Fujita Health University Hospital. The p22PHOX C242T polymorphism was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Gastritis scores of antral gastric mucosa were assessed according to the updated Sydney system.

RESULTS

The 436 patients represented 106 gastric ulcers (24.3%), 48 duodenal ulcers (11.0%), and 282 non-ulcer subjects (64.7%). No association was found between p22PHOX polymorphism and the risk of ulcer diseases compared to non-ulcer subjects. However, among H. pylori-positive subjects, the degree of intestinal metaplasia tended to be lower in 242T carriers aged more than 60 years (p=0.0488). The same allele also decreased the risk of developing a more severe intestinal metaplasia in H. pylori-positive female subjects (p=0.0441).

CONCLUSIONS

Our data suggest that the p22PHOX 242T allele is associated with a reduced risk of developing a more severe intestinal metaplasia in subjects older than 60 years of age and in female subjects with H. pylori infection.

Genetic polymorphism of interleukin-17A and -17F genes in gastric carcinogenesis

Interleukin-17A (IL-17A) and IL-17F play a role in tissue inflammation by inducing release of proinflammatory and neutrophil-mobilizing cytokines. We investigated the associations between gastric cancer and polymorphisms of IL-17A (rs2275913, G-197A) and -17F (rs763780, 7488 T/C) genes. The study was performed in 811 subjects (524 without gastric cancer and 287 with gastric cancer). We used the multiplex PCR-SSCP method to detect gene polymorphisms. Overall, the number of IL-17A/-197A allele was significantly correlated to the development of gastric cancer (OR, 1.42; 95% CI, 1.09-1.85; p = 0.010). The frequency of IL-17A/-197 A/A homozygote was also significantly higher in gastric cancer group than in non-cancer group (OR, 3.02; 95% CI, 1.86-4.91; p < 0.0001). The IL-17A/G-197A polymorphism was more closely correlated to intestinal-type cancer than diffuse-type cancer. In addition, IL-17A/-197A allele carriers had an increased risk of the development of gastric mucosal atrophy (OR, 1.68; 95% CI, 1.06-2.65; p = 0.026), and a positive relationship between the inflammation score and the number of -197A allele was observed (p = 0.022). We concluded that G-197A polymorphism of IL-17A gene was significantly associated with the development of gastric cancer, especially intestinal-type cancer.

CD14 promoter-159 polymorphism is associated with reduced risk of intestinal-type gastric cancer in a Japanese population

Host genetic factors may play a key role in determining the long-term outcome of the Helicobacter pylori infection. Toll-like receptor 4 (TLR4) and CD14-mediated recognition of lipo-polysaccharide (LPS) is required for efficient recognition of gram-negative bacterial infections. We investigated the effects of common polymorphisms of TLR4 Asp299Gly, Thr399Ile, and CD14 promoter-C159T on the risk of gastric cancer including its subtypes and clinicopathologic features. We also investigated the effects of these polymorphisms on histologic degree of H. pylori-induced gastritis. 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, Peptic ulcer diseases = 43.6%, gastritis = 56.4%) as the control group. TLR4 Asp299Gly, Thr399Ile, and CD14 promoter-C159T were determined by PCR-RFLP in all the patients. Gastritis scores of non-cancerous gastric mucosa were assessed according to the updated Sydney system in H. pylori-positive subjects (n = 179). The frequencies of CD14-260 TT and T carrier were significantly lower in patents with intestinal-type gastric cancer than in controls (OR = 0.31; 95%CI = 0.12-0.78, OR = 0.38; 95%CI = 0.18-0.81, respectively). Compared to patients older than 61 years, the atrophy score in antrum was significantly lower in TT and CT patients. TLR4 Asp299Gly and Thr399Ile were not detected in all the patients. Our data suggests that CD14 promoter-159TT and T carrier were associated with a lower risk of developing gastric mucosal atrophy in H. pylori-infected patients of more than 61 years of age, and these genotypes may reduce the risk of intestinal-type gastric cancer.

Effect of cyclin D1 (CCND1) polymorphism on gastric premalignant condition

BACKGROUND

Cyclin D1 (CCND1) is known to regulate function in G1 arrest and therefore may play an important role in carcinogenesis. The aim of this study was to investigate the effect of G870A polymorphism of the CCND1 gene on gastric precancerous condition, on histological chronic gastritis, and on the risk of peptic ulcer diseases.

METHODS

Restriction fragment length polymorphism analysis was performed for polymorphisms at 870GA in the CCND1 gene in 524 cancer-free subjects, including 111 gastric and 54 duodenal ulcers, and 359 non-ulcer subjects. Gastritis scores of antral gastric mucosa were assessed according to the updated Sydney system in 384 subjects.

RESULTS

CCND1 genotype was significantly associated with the severity of intestinal metaplasia by the Kruskal-Wallis test, and this tendency was especially stronger among older subjects of 61 years or older (overall subjects: p=0.035, 61 years approximately : p=0.007). We also found that the 870AA genotype held a significant high risk of intestinal metaplasia [Helicobacter pylori infection adjusted odds ratio (OR)=1.8, 95% confidence interval (CI)=1.03-3.15, p=0.04]. The same genotype was more closely associated with the risk of intestinal metaplasia in older subjects of 61 years or older (H. pylori infection adjusted OR=3.45, 95% CI=1.48-8.08, p=0.004). A non-significant association was found between CCND1 G870A genotypes and the risk of peptic ulcer diseases as well as histological severity of acute or chronic inflammation.

CONCLUSIONS

It appears that the G870A polymorphism of CCND1 is associated with gastric premalignant condition especially in older subjects.

COMT gene Val158Met polymorphism influences the severity of intestinal metaplasia in H. pylori infected older subjects

BACKGROUND/AIMS

A complex interaction of host genetic and environmental factors may be relevant in the development of Helocobacter pylori (H. pylori) related gastroduodenal diseases. Catechol-O-methyltransferase (COMT) is expressed catalyzes the methylation of various endobiotic and xenobiotic substances and thus might protect DNA from oxidative damage. We aimed to clarify the effect of COMT functional polymorphism on the severity of histological gastritis in a Japanese population.

METHODOLOGY

203 subjects were included in this study. Restriction fragment length polymorphism analysis was performed for polymorphisms at codon 158 in the COMT gene. Gastritis scores of antral gastric mucosa were assessed according to the updated Sydney system.

RESULTS

COMT genotype distribution in the study subjects was 158Val/Val (51.2%), 84Val/Met (41.4%), and 15Met/Met (7.4%). It was within the Hardy-Weinberg equilibrium (p = 0.73). In over all subjects, the degree of intestinal metaplasia tended to be lower among 158Met/Met when compared to Val/Val (Val/Val vs. Met/Met; 0.59 +/- 0.93 vs. 0.13 +/- 0.52, p = 0.052). Among H. pylori infected subjects, the degree of intestinal metaplasia was significantly lower among 158Met carriers in 50 years or older age (Val/Val vs. Met carriers; 1.20 +/- 1.06 vs. 0.75 +/- 1.08, p = 0.0436). No significant association was found between COMT genotypes and the degree of gastritis in different gender

CONCLUSION

Our data suggest that COMT gene 158Met polymorphism is associate with a reduced risk of developing more severe intestinal metaplasia in H. pylori infected older subjects.

Effect of polymorphisms in the 3'-untranslated region (3'-UTR) of VEGF gene on gastric pre-malignant condition

BACKGROUND

A complex interaction of host genetic and environmental factors may be relevant in Helicocobacter pylori-related gastric carcinogenesis. We investigated the effect of VEGF gene polymorphisms on the risk of gastric pre-malignant condition.

PATIENTS AND METHODS

The G1612A and C936T polymorphisms in the 3'-untranslated region (3'-UTR) of the VEGF gene were genotyped in 337 cancer-free individuals. The presence of intestinal metaplasia in the gastric antrum was assessed in all. Gastritis scores were also assessed according to the updated Sydney system.

RESULTS

The 1612 GA genotype held a significantly higher incidence of intestinal metaplasia in H. pylori-positive individuals more than 65 years of age (OR = 4.05, 95% CI = 1.08-15.15, p = 0.038). The degree of intestinal metaplasia was also higher among individuals with 1612 GA in the same generation (GG vs. GA; 0.98 +/- 0.87 vs. 1.55 +/- 0.96, p = 0.026).

CONCLUSION

The G1612A but not the C936T polymorphism of the VEGF gene is associated with gastric pre-malignant condition in older individuals.

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 38.4 +/- 19.6%. 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; 42.9 +/- 19.6% vs. 34.5 +/- 18.9%, P = 0.046). The higher methylation levels were also associated with Steroid-dependent (P = 0.002) and refractory (P = 0.007) UC. Our data suggest that PAR2 methylation status in rectal mucosa correlates with more severe disease phenotypes of UC.

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

BACKGROUND

Inflammation 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.

METHODS

We 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.

RESULTS

Among 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).

CONCLUSION

The -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.

Effect of promoter methylation of multidrug resistance 1 (MDR1) gene in gastric carcinogenesis

BACKGROUND

The altered expression of multidrug resistance 1 (MDR1) contributes to various types of carcinogenesis and their disease progression. Hypermethylation of CpG islands located in the promoter regions is involved in gene silencing at the transcriptional level. The methylation status of MDR1 gene promoter was investigated in gastric cancer in relation to various clinicopathological features.

PATIENTS AND METHODS

The methylation of the MDR1 promoter was estimated in both antral non-neoplastic mucosa and cancer lesions in 83 patients with gastric cancer using a methylation-specific PCR method.

RESULTS

The methylation ratio (MR) of the cancer lesions (31.3 +/- 20.5) was significantly higher than that of non non-neoplastic mucosa (20.9 +/- 31.3, p = 0.0004). The MR was especially high in Lauren's intestinal cancer (p < 0.0001). A higher MR was also observed in more advanced stage (p = 0.005) and lymph vessel invasion-positive cases (p = 0.002).

CONCLUSION

The promoter methylation of MDR1 seems to have a significant role in carcinogenesis and tumor progression in the stomach.

Mannan-binding lectin (MBL) polymorphism and gastric cancer risk in Japanese population

BACKGROUND

Mannan-binding lectin (MBL) is believed to be an important constituent of the innate immune system. It has been reported that the codon 54 G/A polymorphism of exon-1 affects the MBL2 gene and alters its activity.

AIMS

We investigated the association between polymorphism of the MBL2 gene and gastric cancer risk as well as Helicobacter pylori infection in a Japanese population.

METHODS

The study cohort comprised 388 gastric cancer patients and 144 healthy volunteers. Polymorphism at codon 54 of exon 1 of the MBL2 gene was investigated by PCR-based restriction fragment length polymorphism analysis.

RESULTS

There was no significant difference in the distribution of the MBL2 genotype among the gastric cancer patients and healthy controls. However, the carrier of the A allele was more prevalent among patients with a more advanced stage gastric cancer [odds ratio (OR) 1.68, 95% confidence interval (CI) 1.05-2.67; P = 0.03] and also had an increased risk of gastric cancer among patients 65 years of age or younger (OR = 1.6, 95%CI = 1.01-2.52, <0.05).

CONCLUSION

The codon 54 polymorphism of the MBL2 gene is associated with more advanced phenotypes of gastric cancer and the risk of gastric cancer in Japanese patients 65 years of age or younger.

Genetic variant of the p22PHOX component of NADPH oxidase C242T and the incidence of gastric cancer in Japan

BACKGROUND/AIMS

Reactive oxygen species has been implicated in the development of gastric cancer. NADPH oxidase, a major source of superoxide generation play a critical role in H. pylori related gastric inflammation. We aimed to clarify the effect of C242T polymorphism of p22PHOX, an essential component of NADPH oxidase on the risk of gastric cancer, gastric ulcer and duodenal ulcer in a Japanese population.

MATERIALS AND METHOD

376 gastric cancer patients and 436 cancer-free subjects participated in this study. The p22PHOX C242T polymorphism was determined by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

In the non-cancer subjects, the p22PHOX genotype distribution was 365CC (83.7%), 63CT (15.4%), and 4TT (0.9%). Meanwhile, the p22PHOX genotype distribution in gastric cancer was 311CC (82.7%), 63CT (16.8%), and 2TT (0.5%). There was no significant difference between two groups in the distribution of T carrier frequency (OR=1.04, 95% CI=0.71-1.53). No association was also observed between p22PHOX genotypes and Lauren's classification, tumor stage and anatomical locations.

CONCLUSION

It appears that the C242T polymorphism of p22PHOX is not associated with the incidence of gastric cancer in the Japanese population.

Genetic polymorphisms of cyclooxygenase-1 (COX-1) are associated with functional dyspepsia in Japanese women

BACKGROUND

Prostaglandins (PGs), catalyzed from arachidonic acid by cyclooxygenase (COX), are involved in a variety of physiological processes in the stomach. COX-1 has been regarded as a constitutively expressed enzyme that generates prostaglandins for gastrointestinal integrity. We investigated the association between the potentially functional polymorphism T-1676C in the COX-1 gene promoter and functional dyspepsia (FD) in the Japanese population.

METHODS

The study was performed in 272 subjects (185 with no upper abdominal symptoms and 87 with FD). We employed the PCR-SSCP method to detect the gene polymorphism.

RESULTS

Overall, female sex had a 2-2.5-fold risk for the development of FD compared with male sex, whereas the COX-1 gene polymorphism and Helicobacter pylori infection were not associated with susceptibility to FD. However, in female subjects, -1676T allele carriers had a significantly increased risk for the development of FD (OR 2.70, 95%CI 1.04-6.99, p = 0.041), especially the epigastric pain syndrome (EPS) subgroup (OR 4.07, 95%CI 1.15-14.4, p = 0.029).

CONCLUSIONS

Our results provide the first evidence that the COX-1 gene polymorphism is significantly associated with the development of the EPS subgroup of FD in female subjects.

No association between a genetic variant of the p22PHOX component of NADPH oxidase C242T and ulcerative colitis

BACKGROUND/AIMS

Reactive oxygen species has been implicated in the development of ulcerative colitis (UC). NADPH oxidase, a major source of superoxide generation play a critical role in H. pylori related gastric inflammation. We aimed to clarify the effect of C242T polymorphism of p22PHOX, an essential component of NADPH oxidase on the risk of UC in a Japanese population.

METHODOLOGY

123 UC patients and 459 healthy control (HC) subjects participated in this study. The p22PHOX C242T polymorphism was determined by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

In the HC group, the p22 PHOX genotype distribution was 379C/C (82.6%), 79C/T (17.2%), and 5T/T (1.2%). Meanwhile, the p22 PHOX geno type distribution in UC group was 96C/C (78.0%), 26C/T (21.1%), and 1T/T (0.9%). No significant difference of the p22 PHOX genotype distribution was observed between HC and UC groups. (C/C vs. T/T; OR=0.80, 95% CI=0.09-6.84, C/C vs. C/T; OR=1.37, 95% CI=0.83-2.25, C/C vs. T carriers; OR=1.33, 95% CI=0.82-2.18, T/T vs. others; OR=0.74, 95% CI =0.09-6.43). No association was also found between p22PHOX gene polymorphism and different clinicopathological features of UC such as gender, age, age of onset, clinical type, extension of colitis and response to treatment.

CONCLUSIONS

It appears that the C242T polymorphism of p22 PHOX is not associated with the incidence of gastric cancer in the Japanese population.

Serotonin-2A receptor gene T102C polymorphism in patients with dyspeptic symptoms

BACKGROUND/AIMS

The role of genetics in the susceptibility to functional dyspepsia (FD) is unclear. Serotonin (5-HT) is expressed in gastro-intestinal tract and modulates the sensory-motor functions in the digestive tract. Genetic association has been reported between C102T polymorphism in the gene encoding 5-HT 2A receptor (5HTR2A) and various diseases. We aimed to clarify the association between 5HTR2A C102T polymorphism and dyspeptic symptom in a Japanese population.

METHODOLOGY

91 dyspeptics and 93 non-dyspeptic subjects enrolled in this study. Dyspeptic symptoms were divided into 9 categories. 5HTR2A gene T102C polymorphism was determined by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

In the non-dyspeptics, the 5HTR2A geno type distribution was 21TT (22.6%), 50TC (53.8%), and 22CC (23.6%). Meanwhile, the 5HTR2A genotype distribution in dyspeptics was 30 TT (33.0%), 40 TC (43.9%), and 21 CC (23.1%). There was no significant difference between the two groups in the genotype distribution. We did not find any association between 5HTR2A genotypes and dyspeptic patients in different gender and H. pylori infection status. Also, no correlation was found between 5HTR2A polymorphism and any of the 9 different dyspeptic symptoms.

CONCLUSIONS

Our results suggest that 5HTR2A polymorphism is unlikely to be associated with susceptibility of dyspeptic symptoms. The role of genetics to the development of dyspepsia needs further evaluation.

A polymorphism in the 3'-utr of cyclooxygenase-2 and the risk of gastric cancer

A polymorphism within the 3'-UTR 8473T↷C of the cyclooxygenase-2 (COX-2) gene, which plays a role in gastrointestinal cancer development, has been associated with susceptibility to malignant disease. Here, we report on the interaction between the COX-2 3'-UTR T↷C polymorphism and gastric cancer development. DNA from 121 Japanese patients with gastric cancer and 126 age-matched control patients was examined for the COX-2 polymorphism by PCR-RFLP. Odds ratios and the 95% confidence interval (CI) were calculated. Homozygous carriage of the COX-2 8473C allele tended to be associated with an increased risk of gastric cancer compared to the T allele homozygotes of the subjects (OR=3.70; 95% CI, 0.96-14.25). The CC allele was associated with a significant increased risk of diffuse-type gastric cancer (OR=5.29; 95% CI, 1.18-23.70). These findings suggest that the COX-2 3'-UTR 8473T↷C polymorphism could be used as a marker for genetic susceptibility to gastric cancer in Japanese populations.

Association of endoscopic appearances with dyspeptic symptoms

BACKGROUND

The relationship between endoscopic appearances such as endoscopic gastritis and duodenitis and dyspeptic symptoms has not been clearly demonstrated. We aimed to clarify the association of endoscopic appearances with Helicobacter pylori infection, histological severity of gastritis, and dyspeptic symptoms in a Japanese population.

METHODS

We enrolled 87 dyspeptic and 93 nondyspeptic subjects in this study. All subjects underwent gastroscopy, and patients with active peptic ulcer disease, reflex esophagitis with erosion, polyps >1 cm, or cancer were excluded. Endoscopic appearances in patients with dyspeptic symptoms and in those without were assessed retrospectively on the basis of endoscopic images. The degree of atrophy by the Kimura-Takemoto classification system was also assessed. Helicobacter pylori infection status was examined by histology or antibody against H. pylori. Histological severity of inflammation and glandular atrophy in the antrum were assessed according to the updated Sydney System. The odds ratio (OR) and 95% confidence interval (CI) were calculated by logistic regression using the variables age, sex, H. pylori infection status, and all endoscopic appearances.

RESULTS

The degree of atrophy tended to be lower among dyspeptic patients (P = 0.06). Among all endoscopic appearances, the liner redness (friability) in the antrum (OR = 3.90, 95% CI = 1.20-12.64) and duodenal ulcer (DU) scarring (OR = 3.41, 95% CI = 1.08-10.79) were independently associated with dyspepsia. Histological severity of inflammation and glandular atrophy were not associated with dyspeptic symptoms. Also, no correlation was found between endoscopic appearances and any of the different subgroups of dyspeptic symptoms. Patients with friability in the antrum and DU scar, which correlated with dyspeptic symptom showed some of communal symptoms such as epigastric pain, epigastric discomfort, hypochondriac pain, early satiation/postprandial fullness, and belching, but they differed considerably with respect to H. pylori positivity and the histological severity of gastritis.

CONCLUSIONS

Some endoscopic appearances such as friability in the antrum and DU scarring may be associated with dyspeptic symptoms, and endoscopic appearances may be useful markers to perform clinical implementation reflecting an individual's pathophysiology of dyspeptic symptoms.