Effects of -1018G>A polymorphism of HRH2 (rs2607474) on the severity of gastric mucosal atrophy

BACKGROUND AND AIM

Histamine plays important physiological roles in upper gastrointestinal tract and acts via the H2 receptor. A polymorphism -1018 G>A (rs2067474) was identified in an enhancer element of the HRH2 promoter. We attempted to clarify the associations of this polymorphism with the progression of gastric mucosal atrophy.

METHODS

Gastric mucosa samples were obtained from 398 subjects with no malignancies. The rs2067474 genotype was determined by PCR-SSCP method. The degree of gastritis was assessed in 366 subjects and serum pepsinogen (PG) I/II levels were measured in 108 subjects. The subjects with atrophy score higher or equal to 2 and metaplasia score higher or equal to1 were classified into the severe atrophic gastritis group (SA group).

RESULTS

The -1018G>A minor allele frequencies in SA and non-SA groups were 8.02% and 13.3%, respectively (p=0.057). The -1018 GG homozygote had a significantly high risk for gastric mucosal atrophy (OR: 2.03, 95%CI: 1.03-4.01, p=0.042). In H. pylori positive subjects, GG homozygote was a more significant risk factor for gastric mucosal atrophy (OR: 2.32, 95%CI: 1.12-4.81, p=0.023). In addition, in the subjects older than 60 years, GG homozygote had also a significant risk for gastric mucosal atrophy (OR: 2.63, 95%CI: 1.15-6.00, p=0.022). In -1018 GG homozygote, PG I/II ratio was significantly lower in H. pylori positive than negative subjects and was significantly decreased with age (p=0.0032 by ANOVA), whereas it was not in the A carrier.

CONCLUSIONS

Our results suggest that HRH2 -1018 GG homozygote is a risk factor for the severity of gastric mucosal atrophy under the influence of H. pylori infection, especially in older subjects.

NFKB1 polymorphism is associated with age-related gene methylation in Helicobacter pylori-infected subjects

CpG island aberrant methylation is shown to be an important mechanism in gene silencing. The important role of NF-κB in the inflammatory response to H. pylori colonization has been indicated. We investigated the influence of NFKB1 polymorphisms, -94 ins/del (rs28362491) and -449 C>G (rs72696119), on the aberrant gene methylation under H. pylori infection. Gastric mucosal samples were obtained from sub-subjects without malignancies. Methylation status of genes (p14ARF, p16INK4a, DAPK and CDH1) was determined by methylation-specific PCR (MSP). The genotyping of NFKB1 was performed by PCR-SSCP. There was a strong allelic association between rs28362491 and rs72696119, and all H. pylori-infected -94 del/del homozygotes had a -449 GG genotype. The -94 del/del homozygosity was significantly associated with risk for development of CpG island high methylation (CIHM) (two or more gene methylations), especially DAPK and CDH1 methylations, and the number of methylated genes was significantly higher in -94 del/del homozygotes than in ins/del and ins/ins (ins carrier) H. pylori-infected elder subjects. In addition, this methylated gene number was significantly increased with age in H. pylori-infected del/del homozygotes, but not in infected ins carriers. Furthermore, the inflammation score was significantly higher in H. pylori-infected del/del homozygotes compared to ins carriers. NFKB1 -94 ins/del ATTG polymorphism (rs28362491) was significantly associated with the increased risk for the development of age-related gene methylation in non-cancerous gastric mucosa under H. pylori-induced inflammation.

Association between common genetic variant of HRH2 and gastric cancer risk

Histamine plays important physiological roles in the upper gastrointestinal tract and acts via the H2 receptor. The -1018 G>A (rs2067474) in an enhancer element of the promoter and non-synonymous rs79385261 (Asn46Thr) were identified in HRH2. We attempted to clarify the associations of these polymorphisms with gastric carcinogenesis. The study was performed in 321 patients with gastric cancer and 599 subjects with no evidence of gastric malignancies on upper gastroduodenal endoscopy. The genotypes were determined using a one-tube multiplex PCR-SSCP method. The degree of gastritis was assessed in 496 subjects and serum pepsinogen (PG) I/II levels were measured in 124 subjects without gastric cancer. The minor allele of Asn46Thr could not be detected. The frequencies of the -1018 A allele in the non-GC and GC groups were 13.5% and 8.26%, respectively (p=0.00077). Overall, -1018 GG homozygotes had an increased risk for developing gastric cancer (OR 1.68; 95% CI 1.17-2.42; p=0.0052), especially intestinal type cancer (OR 1.94; 95% CI 1.23-3.08; p=0.0047). In subjects aged >60 years, the adjusted risk for gastric cancer among individuals who were -1018 GG homozygotes was 1.87 (range 1.19-2.93; p=0.0065) compared with A carriers. In the gastric cancer cases located in the antrum and at comparative advanced stage, -1018 GG homozygosity was a significantly increased risk factor. In subjects >60 years, the metaplasia score was significantly higher in -1018 GG homozygotes than A carriers. Both atrophy and metaplasia scores were significantly increased with age only in -1018 GG homozygotes. The PG I/II ratio was significantly decreased in H. pylori positive GG homozygotes than negative GG homozygotes and positive A carriers. Our results suggest that -1018 GG homozygosity of HRH2 may be associated with the severity of gastric mucosal atrophy. This genotype has an increased risk for the subsequent development of gastric cancer, especially intestinal type, at advanced age.

Genetic polymorphisms of IL17A and pri-microRNA-938, targeting IL17A 3'-UTR, influence susceptibility to gastric cancer

We report an association between gastric cancer (GC) and polymorphisms in IL17A, rs2275913 (-197 G > A), rs3748067 (*1249 C > T), and pri-miR-938, rs2505901 (T > C). We employed the multiplex PCR-SSCP method to detect gene polymorphisms in 337 GC cases and 587 controls. The minor allele frequency of rs2275913 was significantly higher, and those of rs3748067 and rs2505901 significantly lower, in GC cases than controls. The rs2275913 AA homozygote was associated with an increased risk (OR, 2.38; 95%CI, 1.63-3.46; p < 0.0001) for the development of both intestinal and diffuse types of GC. The rs3748067 T polymorphism was associated with a decreased risk for intestinal GC (OR, 0.511; 95%CI, 0.272-0.962; p = 0.037), whereas rs2505901 C locus carried a decreased risk overall for GC (OR, 0.733; 95%CI, 0.545-0.985; p = 0.039). In addition, rs3748067 T allele was inversely correlated with lymph node metastasis. Our results suggest that polymorphisms in both IL17A and pri-miR-938 contribute to cancer risk susceptibility and therefore can affect the development of gastric cancer.

Presence of minimal change esophagitis closely correlates with pathological conditions in the stomach

INTRODUCTION

It is suggested that minimal change (grade M) esophagitis is a spectrum of gastric acid reflux disease. We evaluated the clinical significance of grade M esophagitis, including its subtypes (reddish change: MR and whitish change: MW), especially with attempt to pathological conditions in the stomach that relates to gastric acid secretion.

MATERIALS AND METHODS

Using 241 subjects undergoing esophagogastroduodenoscopy for various indications, we investigated the association between grade M esophagitis with histological and serological severity of gastritis and endoscopic degree of atrophy. We also examined its association with ulcer diseases and various symptoms.

RESULTS

When grade M cases were divided into MR and MW, all MR cases had MW in considerable degrees. Dyspeptic symptoms were more likely to be associated with H. pylori negative grade M cases, while presence of duodenal ulcer and its scar were associated with Helicobacter pylori-positive grade M cases. In all subjects, histological parameters, especially in the corpus, were lower in grade M cases compared to normal appearance. In grade M cases, degree of acute and chronic inflammation, and atrophy in corpus were lowest in cases that have grade MR. Grade M cases were also associated with higher pepsinogen I/II ratio and lower endoscopic atrophy.

CONCLUSIONS

Pathological conditions of the stomach relate to higher gastric acid secretion correlates with grade M esophagitis. In grade M cases, appearance of MR may reflect higher gastric acid secretion or severe acid reflux than cases that have grade MW only.

Correlation between magnifying narrow band imaging and histopathology in gastric protruding/or polypoid lesions: a pilot feasibility trial

Background

Several study showed usefulness of microscopic capillaries, seen by magnifying narrow band imaging (NBI) endoscopy for predicting histopathology among superficial depressed or flat elevated gastric neoplasia (GN). Here we assessed the diagnostic efficacy of magnifying NBI for predicting histopathology among gastric protruding/or polypoid lesions.

Methods

Using endoscopic pictures of magnifying NBI from 95 protruding/or polypoid lesions (19 fundic gland polyps: FGP, 47 hyperplastic polyps: HP, and 29 GN), fine mucosal patterns were classified into four categories: small round, prolonged, villous or ridge, and unclear patterns, and micro vascular patterns were classified into five categories: honey comb, dense vascular, fine net work, core vascular, and unclear patterns.

Results

Most suggestive micro vascular patterns for predicting FGP, and HP were honeycomb (sensitivity 94.7%, specificity 97.4%), and dense vascular patterns (sensitivity 93.6%, specificity 91.6%), respectively. Fine net work, core vascular, and unclear patterns presented higher specificity (97%, 100%, and 100%) for predicting GN, and diagnostic efficacy of combined of those patterns was favorable (sensitivity 86.2%, specificity 97.0%).

Conclusion

Micro vascular patterns by using magnifying NBI provides meaningful information for predicting the histopathology of gastric protruding/or polypoid lesions.

Usefulness of transnasal endoscopy where endoscopic submucosal dissection is difficult

BACKGROUND

Early gastric cancer located from the pyloric ring to inside the duodenal bulb (DB) is not easily treated by endoscopic submucosal dissection (ESD). The endoscope needs to be reversed inside the DB to set the resection line at a safe distance from the anal side. Because of the space limitations and limited flexibility of conventional endoscopy (CE), there have been increasing possibilities of complications. Here we report a new ESD technique using a transnasal endoscope (TN-E) that is reversed inside the DB.

METHODS

The subjects were 5 patients with early gastric cancer or adenoma, at locations ranging from the pyloric ring to inside the DB, who were all treated by ESD. We compared results in these patients (TN-E group) with results in five patients with similar disease characteristics who were treated by ESD before July 2008, when the TN-E treatment method was introduced (CE group). In the TN-E group, after marking by CE, we switched the endoscope to the TN-E, and performed the reversing procedure inside the DB, and cut the anal side of the lesion in a semicircle. We switched back to CE to dissect the remaining half on the oral side. We compared the average resection time, en-bloc resection rate, and safety margin between the TN-E and CE groups.

RESULTS

Reversing inside the DB and the anal-side procedures proved easy and there were no complications. No bleeding or perforation occurred. The average resection times and en-bloc resection rates were not different between the two groups. All the resections by the TN-E were more than 5 mm away from the tumor margin, whereas a resection rate with a safety margin of more than 5 mm was 80% by CE.

CONCLUSIONS

In conclusion, the TN-E was safe and effective for use inside the DB. ESD using the TN-E contributed to accurate pathological diagnosis, because the size of the resected specimen was sufficient to prevent the burning effect caused by the ESD.

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.

A Genetic Variant of the CD14 C-159T in Patients with Functional Dyspepsia (FD) in Japanese Subjects

Inflammatory changes in the gastric mucosa are commonly observed in Japanese patients with functional dyspepsia (FD). However, detailed data regarding the relationship between the genetic regulatory factors of inflammation and FD are not available. CD14 is an important mediator of the inflammatory response in the first line of host defense by recognition of Lipopolysaccharide (LPS). We aimed to investigate the association between CD14 promoter C-159T polymorphism and FD in a Japanese population. 108 patients with FD and 99 non-dyspeptic subjects enrolled in this study. Dyspeptic symptoms were divided according to Rome III criteria. CD14 gene C-159T polymorphism was determined by polymerase chain reaction-restriction fragment length polymorphism. In the non-dyspeptics, the CD14 genotype distribution was 28CC (28.3%), 51CT (51.5%), 21TT (21.2%). Meanwhile, the CD14 genotype distribution in FD was 31CC (28.4%), 56CT (51.4%), 22TT (20.2%). The genotype distribution was not significantly different. There was no significant difference between two groups in the genotype distribution. We did not found any association between CD14 genotypes and dyspeptic patients in different gender and Helicobacter pylori infection status. No significant association was also found between CD14 polymorphism and any of different subtypes of FD according to Rome III while there was a weak correlation between TT genotype and PDS in male subjects (TT vs others, OR = 3.18, 95% CI = 0.98−10.26, p = 0.06). In conclusion, our results suggest that CD14 polymorphism is unlikely to associate with susceptibility of dyspeptic symptoms. The role of inflammation related-gene polymorphisms to the development of dyspepsia needs to further evaluation.

Analysis of Beta-Tubulin Gene Exon 4 Mutations in Advanced Stage III or IV Gastric Cancer

The mechanisms that cause chemoresistance of gastric cancer have yet to be elucidated. Taxanes and promising agents that were recently approved for treatment of advanced or recurrent gastric cancer. Mutations of beta-tubulin, which is a target of taxianes, have been shown to confer chemoresistance against these agents. The aim of the present study is to investigate the presence of mutations of the beta-tubulin in gastric cancer tissues. Sixty-six patients with advanced stage III or IV gastric cancer patients enrolled in this study. Paired samples of gastric cancer tissue and normal mucosa were obtained by endoscopy. The guanosine 5'-triphosphate (GTP)-binding site in exon 4 of the beta-tubulin gene was examined by polymerase chain reaction single-strand conformational polymorphism (PCR-SSCP) analysis, followed by sequencing of the products with abnormally shifted bands. SSCP analysis showed abnormal bands upstream of the GTP-binding site in 7 of the 66 patients, but sequence analysis found no nucleotide substitutions in these patients. Three variant bands were also detected down stream of the the GTP-binding site, but the sequences of the 3 products corresponded to those of two independent pseudogenes. Thus, none of the tumor samples showed mutation of the beta-tubulin exon 4 GTP-binding site. In conclusion, these findings suggest that mutations of the beta-tubulin gene are rare and are unlikely to be an important cause of taxane resistance to taxians.

Characterization of human-type monoclonal antibodies against reduced form of hemin binding protein 35 from Porphyromonas gingivalis

BACKGROUND AND OBJECTIVE

The gram-negative anaerobe Porphyromonas gingivalis has been implicated as an important pathogen in the development of adult periodontitis, and its colonization of subgingival sites is critical in the pathogenic process. We previously identified a 35 kDa surface protein (hemin binding protein 35; HBP35) from P. gingivalis that exhibited coaggregation activity, while additional analysis suggested that this protein possessed an ability to bind heme molecules. For development of passive immunotherapy for periodontal diseases, human-type monoclonal antibodies have been prepared using HBP35 as an antigen in TransChromo mice. In the present study, we focused on a single antibody, TCmAb-h13, which is known to inhibit heme binding to recombinant HBP35. The aim of our investigation was to clarify the redox-related function of HBP35 and consider the benefits of human-type monoclonal antibodies.

MATERIAL AND METHODS

To examine the antigen recognition capability of TCmAbs with immunoblotting and Biacore techniques, we used the native form as well as several Cys-to-Ser variants of recombinant HBP35.

RESULTS

We found that the redox state of recombinant HBP35 was dependent on two Cys residues, (48) C and (51) C, in the thioredoxin active center (WCGxCx). Furthermore, TCmAb-h13 recognized the reduced forms of recombinant HBP35, indicating its inhibitory effect on P. gingivalis growth.

CONCLUSION

Hemin binding protein 35 appears to be an important molecule involved in recognition of the redox state of environmental conditions. In addition, TCmAb-h13 had an inhibitory effect on heme binding to recombinant HBP35, thereby interfering with P. gingivalis growth.

Polymorphism of the salt sensitivity gene angiotensinogen and gastric cancer risk

A high-salt diet is a risk factor for gastric cancers other than those caused by Helicobacter pylori. The angiotensinogen (AGT) M235T polymorphism has been associated with salt sensitivity. The aim of the present study was to clarify the association between the AGT M235T polymorphism and gastric cancer. The AGT M235T polymorphism was genotyped using PCR-RFLP analysis in 206 gastric cancers and 210 control biopsies. A logistic-regression analysis was performed to identify an odds ratio to determine whether a correlation exists between genetic polymorphism and risk in patients with gastric cancer as compared to the control samples. Statistical significance was determined using the Mann Whitney U and Chi-square tests. The genotype distribution was found to be MM=9 (4.4%), MT=57 (27.7%), and TT=140 (67.9%) in samples from patients with gastric cancer and MM=8 (3.8%), MT=60 (28.6%) and TT=142 (67.6%) in the control samples. The odds ratio of gastric cancer of the MM genotype associated with the T carrier was 1.0 (0.4-2.7) (P=0.95). The distribution pattern of AGT M235T polymorphism in the gastric cancer cases and controls was not found to be significantly different in this study. Thus, it can be concluded that other sites of AGT polymorphism or other salt sensitivity genes may be associated with gastric cancer.

Usefulness of magnifying narrow-band imaging endoscopy in the Helicobacter pylori-related chronic gastritis

Combining the narrow-band imaging (NBI) system and magnifying endoscopy allows simple and clear visualization of microscopic structures of the superficial mucosa and its capillary patterns, which may be useful for precise endoscopic diagnosis in the gastrointestinal tract, being more closely to histopathological diagnosis. In the non-neoplastic gastric mucosa, there have been reports showing a potential usefulness of magnifying NBI for the diagnosis of Helicobacter pylori infection, degree of histological gastritis, and intestinal metaplasia. We have shown that magnifying NBI appearances in the non-neoplastic gastric mucosa also predicts pepsinogen levels, which indicates extension of gastric atrophy in the entire stomach, and gastric cancer occurrence. Furthermore, we have shown that magnifying NBI appearances predicts the result of H. pylori treatment. Clear visualization of fine mucosal and capillary patterns, obtained by magnifying NBI, allows prediction of the histological condition, more in detail without biopsy, and it may also be useful for less invasive, and cost-effective endoscopic gastric cancer surveillance, and prediction of H. pylori eradication.

Association between genetic polymorphisms related to DNA repair or xenobiotic pathways and gastric premalignant conditions

BACKGROUND

Genetic factors related to DNA repair or xenobiotic pathways might confer different degrees of susceptibility to Helicobacter pylori (H. pylori)-related gastric carcinogenesis. The association between XRCC1 Arg399Gln, and Arg194Trp, GSTP1 Ile104Val, and GSTT1, GSTM1 null polymorphisms with gastric intestinal metaplasia, severity of histological gastritis, and peptic ulcer diseases were evaluated in a Japanese population.

PATIENTS AND METHODS

XRCC1 Arg399Gln and Arg194Trp, GSTP1 Ile104Val and GSTT1, GSTM1 null polymorphisms were genotyped in 280 cancer-free individuals, including 52 gastric and 31 duodenal ulcer patients.

RESULTS

Among the five polymorphisms, a significant association between the GSTT1 and GSTM1 null genotypes and increased risk of intestinal metaplasia was found (GSTT1 null: OR=2.42, 95% CI=1.28-4.60, p=0.007, GSTM1 null: OR=2.18, 95% CI=1.15-4.13, p=0.019). When the severity of gastric atrophy was classified into the following three groups: non-atrophy (NA) (atrophy score=0 and metaplasia score=0); severe atrophy (SA) (atrophy score≥2 or metaplasia score≥2) and mild atrophy (MA) (all others), both the GSTT1 and GSTM1 null genotypes held significantly higher risk for developing more severe gastric atrophy (GSTT1 null, SA vs. others: OR=1.95, 95% CI=1.07-3.52, p=0.028, GSTM1 null, NA vs. others: OR=2.57, 95% CI=1.16-5.67, p=0.019, SA vs. others: OR=1.90, 95% CI=1.06-3.42, p=0.032). A significant association was also found between GSTM1 null genotype and increased risk of ulcer diseases (all ulcers: OR=2.42, 95% CI=1.37-4.26, p=0.002, gastric ulcer: OR=2.18, 95% CI=1.11-4.29, p=0.025, duodenal ulcer: OR=2.62, 95% CI=1.15-6.00, p=0.023).

CONCLUSION

Both the GSTT1 and GSTM1 null genotypes are associated with gastric pre-malignant conditions.

Polymorphisms of DNA repair and xenobiotic genes predispose to CpG island methylation in non-neoplastic gastric mucosa

BACKGROUND

Genetic factors, related to DNA repair or xenobiotic pathways might confer different degrees of susceptibility to gastric carcinogenesis. CpG island hyper methylation (CIHM) is a major event in gastric carcinogenesis. We evaluated the association between XRCC1, GSTP1, GSTT1 and GSTM1 polymorphisms with CIHM status in non-neoplastic gastric mucosa.

METHODS

XRCC1 Arg399Gln, and Arg194Trp, GSTP1 Ile104Val, and GSTT1, GSTM1 null polymorphisms were genotyped in 415 cancer free subjects, in relation to four candidate CpG (p14, p16, DAP-kinase and CDH1) loci, assessed by Methylation-Specific-Polymerase Chain Reaction (MSP). CIHM high was defined as two or more CpG islands methylated.

RESULTS

 Significant association between XRCC1 codon 399 Gln/Gln genotype and reduced susceptibility to CIHM of DAP-kinase (adjusted OR = 0.30, 95%CI = 0.13-0.71, p = .0055) and CIHM high (OR = 0.42, 95%CI = 0.19-0.97, p = .04). XRCC1 codon 399 Gin/Gln genotype also presented lower number of CIHM when compared with both Arg/Gln, and Arg/Arg + Arg/Gln genotypes (p = .02, .046, respectively) When subjects were divided according to age (>50 and <50), an association was found between GSTM1 null genotype and increased susceptibility to CIHM high in the 50 years and older generations (OR = 1.63, 95%CI = 1.01-2.62, p = .045).

CONCLUSION

XRCC1 codon 399 Gln/Gln genotype is associated with reduced susceptibility to CIHM especially DAP-kinase. GSTM1 null genotype may increase the susceptibility to CIHM especially in older patients. Genetic factors, related to DNA repair or xenobiotic pathways may have a role in CIHM-related gastric carcinogenesis.

Effect of polymorphisms of IL-1β and TNF-α genes on CpG island hyper methylation (CIHM) in the nonneoplastic gastric mucosa

CpG island hyper methylation (CIHM) is one of the major events in gastric carcinogenesis. To evaluate the influence of host genetic factors in CIHM related carcinogenesis, we investigated the association between common polymorphisms in IL-1β and TNF-α genes, with CIHM status in the nonneoplastic gastric mucosa. Polymorphisms in the IL-1β gene (-31T>C and -511C>T) and the TNF-α gene (-857C>T) were genotyped in 385 cancer-free subjects. CIHM of four candidate genes: p16 (INK4a), p14 (ARF), E-cadherin (CDH1), and death-associated protein kinase (DAP-kinase), were determined by methylation-specific-polymerase chain reaction (MSP). CIHM high was defined as two or more CpG islands methylated. CIHM of all four genes and CIHM high were significantly associated with Helicobacter pylori infection status. In over all, significant marginal association was found between IL-1β-511 TT genotype and reduced susceptibility to CIHM of DAP-kinase (adjusted OR = 0.48, 95% CI = 0.29-0.78) and CIHM high (adjusted OR = 0.53, 95% CI = 0.32-0.86). This association was more enhanced in subjects 65 yr or younger age. We also found positive association between TNF-α-857T carrier and increased susceptibility to CIHM of CDH (adjusted OR = 1.78, 95% CI = 1.01-3.16), and CIHM high (adjusted OR = 1.86, 95% CI = 1.04-3.33) in the same generation. The mean number of CIHM was lower in subjects with IL-1β-511TT genotype, while the mean number was higher in subjects with TNF-α-857 T carrier especially in subjects 65 yr and younger patients. IL-1β-511 TT genotype is associated with reduced susceptibility to CIHM especially in younger generation. Furthermore, the TNF-α-857T carrier is associated with increased susceptibility of CIHM in the same generation.

Host genetic factors, related to inflammatory response, influence the CpG island methylation status in colonic mucosa in ulcerative colitis

BACKGROUND

CpG island hypermethylation (CIHM) in gene promoter is frequently observed in the colonic mucosa in ulcerative colitis (UC), and is strongly involved in UC-associated colorectal carcinogenesis (CRC). The influence of common single nucleotide polymorphisms (SNPs) related to inflammatory immune response on the individual susceptibility to CIHM status in the non-neoplastic rectal mucosa in UC patients was evaluated.

PATIENTS AND METHODS

Ten candidate SNPs, multidrug resistance 1 (MDR1) 3435 (C>T), regulated upon activation, normal T-cell expressed and secreted (RANTES)-28 (C>G), heat-shock protein (HSP)70-2 1267 (B>A), NADPH oxidase p22PHOX 242 (C>T), Toll-like receptor (TLR)2-196 to -174 (ins >del), CD14-159 (C>T), Mannan-binding lectin (MBL)2 codon 54 (G>A), tumor necrosis factor-α(TNF-α) -857 (C>T), interleukin-1β(IL-1β)-511 (C>T), and IL-1β -31 (T>C) were genotyped in 58 UC patients without neoplastic lesions, in relation to CIHM in the rectal mucosa of three candidate CpG (p14, p16 and E-cadherin: CDH1) loci, assessed by methylation-specific-polymerase chain reaction (MSP). High CIHM was defined as two or more CpG islands methylated.

RESULTS

The CD14-159TT genotype held a significantly higher susceptibility to CIHM of the p16 promoter (OR=3.82, 95%CI=1.06-13.79, p=0.04) A significant association was also found between the IL-1β-31TC genotype and reduced susceptibility to high CIHM (OR=0.14, 95%CI=0.22-0.94, p=0.04). The p22PHOX 242CT genotype and MBL2 codon 54 A carrier (GA+AA) were significantly associated with a lower mean number of CIHM (p=0.029, 0.046, respectively).

CONCLUSION

CD14 -159, IL-1β-31, p22PHOX 242 and MBL2 codon 54 SNPs may influence the CIHM status in the rectal mucosa of UC patients and may therefore be substantially involved in UC-associated carcinogenesis.

Functional promoter polymorphisms of macrophage migration inhibitory factor in peptic ulcer diseases

Macrophage migration inhibitory factor (MIF) is a key proinflammatory mediator, which plays a pivotal role in inflammatory and immune diseases. We attempted to clarify the association of functional polymorphisms of MIF gene promoter with the development of gastro-duodenal ulcer. The study was performed in 471 stocked DNAs obtained from the subjects, including 93 healthy volunteers, with no evidence of gastric malignancy. We employed the PCR-SSCP method to detect gene polymorphisms. In all 471 DNAs, 92 and 43 were obtained from gastric and duodenal ulcer patients, respectively. By an unadjusted analysis, infection with Helicobacter pylori (H. pylori), male gender and non-steroidal anti-inflammatory drug (NSAID/aspirin) use were significantly associated with a risk for developing a gastric ulcer, whereas MIF promoter polymorphisms were not. On the other hand, infection with H. pylori, male gender and 7-CATT repeat at position -794 were significantly associated with the development of a duodenal ulcer, whereas NSAID/ aspirin use was not. By the analysis after adjustment for age, gender, NSAID/aspirin use and H. pylori infection status, 7/7-CATT homozygote had a significantly increased risk for the development of duodenal ulcers (OR, 6.31; 95% CI, 1.50-26.6; p=0.012). No factors were significantly associated with the development of peptic ulcers in NSAID/aspirin users. Our results suggested that tetranucleotide repeat polymorphism of MIF gene promoter might be associated with the development of duodenal ulcers.

Changes in gastric mucosal patterns seen by magnifying NBI during H. pylori eradication

BACKGROUND

Magnifying narrow-band imaging (NBI) endoscopy visualizes superficial gastric mucosal and capillary patterns. We aimed to investigate changes in gastric mucosal patterns seen by magnifying NBI endoscopy after Helicobacter pylori eradication.

METHODS

Gastric mucosal patterns in non-pathological gastric corpus were observed by magnifying NBI endoscopy before and 12 weeks after H. pylori eradication in thirty patients. By using paired photographs of each case, changes in NBI mucosal patterns during H. pylori eradication were judged in a consensus manner by three blinded endoscopists.

RESULTS

At 12 weeks after H. pylori eradication, 20 of 24 subjects who had been successfully treated showed remarkable changes in gastric mucosal patterns (sensitivity 83.3%, specificity 100%). In the specimens from these subjects, the patterns of enlarged or elongated pits were improved to small oval or pinhole-like round pits, and the density of fine irregular vessels was decreased. Histological assessment showed alleviation of chronic inflammation in all subjects (p < 0.0001), while such a change was not observed for four subjects showing severe gastric atrophy and intestinal metaplasia. When the subjects were divided according to the presence of severe gastric atrophy, the diagnostic efficacy of magnifying NBI for predicting the results of H. pylori eradication was excellent in subjects without severe gastric atrophy and intestinal metaplasia (sensitivity and specificity, 100%). However, no change in the NBI mucosal pattern was observed in subjects with severe gastric atrophy and intestinal metaplasia, regardless of the H. pylori eradication result.

CONCLUSIONS

At least in subjects without severe gastric atrophy or intestinal metaplasia, successful H. pylori eradication treatment shows improvements in gastric mucosal patterns with the use of magnifying NBI endoscopy early after successful treatment.

Effect of genetic polymorphisms related to DNA repair and the xenobiotic pathway on the prognosis and survival of gastric cancer patients

BACKGROUND

A number of association studies have focused on the effect of polymorphisms related to DNA repair or the xenobiotic pathway, on the susceptibility to gastric cancer (GC). Here, the possible association between common polymorphisms in the X-ray repair cross-complementing groups (XRCC) 1, and glutathione-S-transferase (GST) genes and various clinicopathological characteristics, including overall survival, in GC patients were evaluated.

PATIENTS AND METHODS

XRCC1 Arg399Gln, and Arg194Trp, GSTP1 Ile104Val, and GSTT1, GSTM1 null polymorphisms were determined in 130 GC patients.

RESULTS

XRCC1 codon 194 Trp carriers (Trp/Trp + Arg/Trp) held a significantly higher risk of venous invasion (OR = 3.76, 95%CI = 1.05-13.51, p = 0.043). A similar trend was also found for the XRCC1 codon 194 Trp/Trp genotype (OR = 2.15, 95% CI = 0.87-5.34, p = 0.099). The frequencies of the XRCC1 codon 399 Gln/Gln and Arg/Gln genotypes tended to be lower in lymphatic invasion-positive GC (XRCC1 codon 399 Gln/Gln: OR = 0.27, 95% CI = 0.06-1.15, p = 0.075, Gln/Gln + Arg/Gln: OR = 0.46, 95% CI = 0.20-1.06, p = 0.069), while the frequencies of the XRCC1 codon 194 Trp/Trp genotype tended to be higher in lymphatic invasion-positive GC (XRCC1 codon 194 Trp/Trp: OR = 7.70, 95% CI = 0.95-62.60, p = 0.056). The patients with the GSTT1 null genotype showed significantly better overall survival than the patients with the GSTT1 present genotype (p = 0.019).

CONCLUSION

XRCC1 codon 194 Trp carrier status is correlated with more aggressive biological behavior of GC, such as venous invasion, and the GSTT1 null genotype is associated with better survival in GC patients.

Effect of IL-1β and TNF-α polymorphisms on the prognosis and survival of gastric cancer patients

So far, a number of association studies have focused on the effect of polymorphisms in IL-1β and TNF-α genes on the susceptibility to gastric cancer (GC). Here, we evaluate the possible association between common polymorphisms in the IL-1β and TNF-α genes with various clinicopathological characteristics, including overall survival of GC patients. Restriction fragment length polymorphism analysis was performed for IL-1β-31(T > C) and IL-1β-511(C > T) and TNF-α-857 (C > T) polymorphisms in 130 GC patients. IL-1β-31CC and IL-1β-511TT genotypes held a significantly lower risk of lymphatic invasion (IL-1β-31CC vs. others: adjusted OR = 0.39, 95% CI = 0.15-0.96, P = 0.04, IL-1β-511TT vs. others: adjusted OR = 0.23, 95% CI = 0.08-0.67, P = 0.007). The IL-1β-31CC and IL-1β-511TT genotypes were weakly associated with reduced risk of venous invasion (IL-1β-31CC vs. others: adjusted OR = 0.35, 95% CI = 0.12-1.05, P = 0.06, IL-1β-511TT vs. others: adjusted OR = 0.32, 95% CI = 0.08-1.20, P = 0.09). The IL-1β-511TT genotype was also weakly associated with reduced risk of lymph node metastasis (IL-1β-511TT vs. others: adjusted OR = 0.42, 95% CI = 0.17-1.04, P = 0.06). When the TNF-α-857CT and TNF-α-857-TT genotypes were considered as T carrier, the patients with TNF-α-857T carrier showed significantly better overall survival than patients with CC genotype (P = 0.011). GC patients who have both IL-1β-31 CC and IL-1β-511 TT genotypes and have at least one of protective genotypes (IL-1β-31 CC, IL-1β-511 TT, TNF-α-857 T carrier) were also associated with better prognostic factors, such as lymphatic and venous invasion better survival. IL-1β-31CC, IL-1β-511TT genotype, and TNF-α-857T carrier may have protective effect against GC progression.

Association between polymorphisms in the XRCC1 and GST genes, and CpG island methylation status in colonic mucosa in ulcerative colitis

CpG island hypermethylation (CIHM) is frequently observed in the colonic mucosa in ulcerative colitis (UC) and is deeply involved in UC-associated colorectal carcinogenesis. We evaluated the influence of common polymorphisms related to DNA repair or xenobiotic pathway (XRCC1, GSTP1, GSTT1, and GSTM1) on the individual susceptibility to CIHM status in the non-neoplastic rectal mucosa in UC patients. XRCC1 Arg399Gln and Arg194Trp, GSTP1 Ile104Val, and GSTT1, GSTM1 null polymorphisms were genotyped in 84 UC patients without neoplastic lesions, in relation to CIHM in the rectal mucosa of three candidate CpG loci (p14, p16, and CDH1) assessed by methylation-specific polymerase chain reaction. XRCC1 codon 399 Arg/Gln genotype (odds ratio (OR) = 0.31, 95%CI = 0.12-0.81, p = 0.017) and 399 Gln carrier (GlnGln+Arg/Gln: OR = 0.30, 95%CI = 0.12-0.76, p = 0.01) were significantly associated with reduced susceptibility to CIHM of the CDH1 promoter. GSTP1 Val carrier (Ile Val+Val/Val) also held a significantly lower susceptibility to CIHM of the p16 promoter (OR = 0.26, 95%CI = 0.08-0.86, p = 0.028). In contrast, GSTT1 present genotype (OR = 3.16, 95%CI = 1.27-7.89, p = 0.01) was significantly associated with increased susceptibility to CIHM of the same gene. XRCC1 codon 399 Gln/Gln genotype was significantly associated with lower mean number of CIHM when compared to the Arg/Arg genotype (1.53 ± 1.01 vs. 0.63 ± 1.06, p = 0.024). In addition, the GSTP1 Ile/Val carrier (Ile/Val+Val/Val) was also significantly associated with lower mean number of CIHM (1.43 ± 1.03 vs. 0.84 ± 1.07, p = 0.03). XRCC1 Arg399Gln and GSTP1 Ile104Val polymorphisms may influence the CIHM status in the rectal mucosa of UC patients and may be substantially involved in UC-associated carcinogenesis.

The G-protein β3 polymorphism is associated with diffuse type gastric cancer in Japanese

From epidemiological evidence a high salt diet is a risk factor for gastric cancer, independent of Helicobacter pylori infection, and animal studies have shown that salt promotes carcinogenesis. The G-protein β 3(GNB3) C825T polymorphism has been linked with hypertension, salt sensitivity and multiple diseases. Our aim in this study was to clarify any association of the GNB3 C825T polymorphism with gastric cancer risk in Japanese. We examined 161 patients with gastric cancer and 183 control subjects. All underwent stomach biopsy by endoscopic procedures, and extracted DNA was genotyped using a primer pair including the GNB3 C825T polymorphism area by PCR-based restriction fragment length polymorphism (PCR-RFLP). Logistic-regression analysis was performed to assess the impact of the genetic polymorphism. Overall comparison of genotype frequency showed the CT genotype in control patients to be relatively infrequent, but no statistically significant differences were found. However, on comparison of subtypes of gastric cancer (intestinal and diffuse), a significantly increased risk of diffuse type of gastric cancer was foudn for the TT genotype (odds ratio compared to CC, 3.1, 95%CI 1.1-8.6, p=0.03). In conclusion, the TT genotype of GNB3 was associated with diffuse type of gastric cancer. The mechanism of the GNB3 polymorphism interaction with gastric cancer development needs to be clarified by future study.

Association between common genetic variants in pre-microRNAs and gastric cancer risk in Japanese population

BACKGROUND

Common single-nucleotide polymorphisms (SNPs) in microRNAs (miRNA) have been shown to be associated with susceptibility to several human cancers. We evaluated the associations of three SNPs (rs11614913, rs2910164, and rs3746444) in pre-miRNAs (miR-196a2, miR-146a, and miR-499) with the risk of gastric cancer (GC) and peptic ulcer diseases, and with the severity of Helicobacter pylori-induced gastritis in Japanese population.

METHODS

The rs11614913 (C>T), rs2910164 (G>C), and rs3746444 (A>G) SNPs were genotyped in 552 GC, and 697 non-cancer subjects, including 141 gastric and 73 duodenal ulcer, and 483 non-ulcer subjects. The degree of histologic gastritis was classified according to the updated Sydney System, and the serum pepsinogen levels were measured in selected 579 and 204 cases.

RESULTS

The rs2910164 CC genotype held a significantly higher risk of GC when compared to non-cancer subjects (adjusted odds ratio (OR) = 1.30, 95% confidence interval (CI) = 1.02-1.66, p =.03). Similarly, the rs2910164 C carrier was associated with higher risk of GC when compared to both non-cancer and non-ulcer subjects (OR = 1.39, 95%CI = 1.00-1.93, p =.05, adjusted OR = 1.57, 95%CI = 1.09-2.27, p =.016, respectively). The rs2910164 CC genotype was associated with non-cardia and upper third, diffuse type and advanced stage GC. The rs11614913 TT genotype was associated with higher degree of mononuclear cell infiltration (score 0-1 vs 2∼, adjusted OR = 1.62, 95%CI = 1.05-2.49, p =.03).

CONCLUSIONS

The rs2910164 (G>C) SNP in the miR-146a is associated with susceptibility to GC. In addition, the rs11614913 (C>T) SNP in the miR-196a2 is associated with the degree of H. pylori-induced mononuclear cell infiltration.