Light blue crest and ridge/villous patterns in the uninvolved gastric antrum by magnifying NBI endoscopy correlate with serum pepsinogen and gastric cancer occurrence.

BACKGROUND/AIMS: Combining the magnifying endoscopy and the narrow-band imaging (NBI) system is an endoscopic imaging technique for the enhanced visualization of mucosal microscopic structure and capillaries of the superficial mucosal layer. Light blue crest (LBC) and, ridge/villous pattern have been thought to be suggestive signs for gastric intestinal metaplasia (IM) of magnifying NBI endoscopy. Since the IM is related to gastric cancer risk (GC), the prevalence of LBC and ridge/villous pattern in the nonneoplastic gastric antrum was examined in relation to gastric cancer (GC) risk and serological severity of gastritis. METHODOLOGY: In 100 subjects including 13 GC patients, gastric mucosal pattern were examined using magnifying NBI. The mucosal patterns in the antrum were classified according to the presence of LBC or ridge/villous pattern. Serum pepsinogen (PG) levels were also examined. RESULTS: The sensitivity and specificity for predicting IM was the best when LBC and ridge/villous patterns were combined (sensitivity 95.2%, specificity 98.7%). Both LBC and ridge/villous pattern showed lower serum PGI and PGI/II ratio than those without (P = 0.046, 0.0005, respectively.) In particular, PGI/II ratio was lowest in ridge/villous pattern. The LBC and ridge/villous pattern showed higher incidence of all GC and diffuse GC compared to those without (P = 0.002, 0.002, respectively). CONCLUSIONS: LBC and ridge/villous pattern in uninvolved gastric antrum by magnifying NBI endoscopy are useful signs for predicting gastric atrophy in the entire stomach and GC risk.

Examination of serum pepsinogen in functional dyspepsia.

BACKGROUND/AIMS: Although serum pepsinogen (PG) is considered as a marker of gastric atrophy, it also reflects gastric acid secretion, which closely influences dyspeptic symptoms. We investigated serum PG levels and PGI/PGII ratios in dyspeptic patients, in relation to various different subtypes of symptoms including Rome III classifications. METHODOLOGY: Serum PGs were measured in 75 subjects with dyspeptic symptoms and 42 asymptomatic healthy subjects. RESULTS: PG II level was significantly higher (p=0.0001) and PG I/II ratio was significantly lower (p<0.0001) in subjects with H. pylori infection than those without, while no associations were found between PG levels and usage of H2 receptor antagonists or proton-pump inhibitors. In all subjects with pain in stomach, abdominal bloating and PDS-like symptoms according to Rome III criteria, presented significantly higher levels of PGI, compared to subjects without symptoms (p=0.043, 0.015 and 0.037, respectively). In addition, burning sensation and abdominal pain presented significantly higher PGI/II ratios (p=0.0005 and 0.003, respectively), and higher PGI/II ratio was also positively correlated with a number of symptoms (p=0.04). When subjects were divided according to H. pylori infection status, higher PGI/II ratio was significantly associated with abdominal pain in H. pylori negative subjects (p=0.03), while higher PGI level was significantly associated with functional esophageal disorders (FEG) according to Rome III criteria, and higher number of dyspeptic symptoms in H. pylori positive subjects (p=0.016). CONCLUSIONS: Our data suggest that subjects with higher PGI level, and PG I/II ratio are more likely to develop several dyspeptic symptoms.

Synergistic effect of IL-1ß and TNF-α polymorphisms on the H. pylori-related gastric pre-malignant condition.

BACKGROUND/AIMS: We investigated the effect of IL-1ß and TNF-α polymorphisms, and its synergistic effect with age, gender and H. pylori status on the gastric pre-malignant condition. METHODOLOGY: IL-1ß-31(T>C) and -511(C>T) and TNF-α-857 (C>T) polymorphisms were genotyped in 123 cancer free subjects. Degree of histological gastritis in both antrum and corpus, and extension of endoscopic gastric atrophy were also evaluated. RESULTS: Significant associations were found between degrees of mononuclear cell infiltration (p=0.007) and atrophy (p=0.01) in the antrum with IL-1ß-31(T>C) polymorphism, and degree of endoscopic gastric atrophy with both IL-1ß-31(T>C), -511(C>T) polymorphisms (p=0.03, 0.04, respectively). When subjects were divided into the 3 groups according to the histological severity of gastric mucosal atrophy: the non-atrophic gastritis (NA) group (atrophy score=0 and metaplasia score=0), the severe atrophic gastritis (SA) group (atrophy score>=2 or metaplasia score>=2), and the mild atrophic gastritis (MA) group (all others), synergistic effect was found between numbers of IL-1ß-31C, IL-1ß-511T variant alleles with co-factors on the development of gastric atrophy in the antrum (gender + H. pylori + number of IL-1ß-31C allele: p=0.001, age + gender + H. pylori + number of IL-1ß-31C allele: p=0.0008, gender + H. pylori + number of IL-1ß-511T allele: p=0.016, age + gender + H. pylori + number of IL-1ß-511T allele: p=0.013), while such association was found for TNF-α-857 T allele in the antrum and all genotypes in the corpus. CONCLUSIONS: IL-1ß-31C, IL-1ß-511T variant alleles may accelerate gastric mucosal inflammation and atrophy, not only by themselves, but also through the interaction with co-factors.

Role of heat-shock protein (HSP) 70-2 genotype in peptic ulcer in Japanese population.

BACKGROUND/AIMS: There have been reports showing the protective role of inducible heat-shock protein (HSP) 70 in gastric epithelial cells. An A to G transition at the 1267 position HSP70-2 gene has been shown to be associated with a different level of HSP70 mRNA expression. We aimed to clarify the effect of HSP70-2 polymorphism on the risk of peptic ulcer diseases in a Japanese population. METHODOLOGY: A total of 519 subjects participated in this study. All subjects underwent upper gastroscopy. Restriction fragment length polymorphism analysis was performed for polymorphisms at 1267 of HSP70-2 gene in all the subjects. RESULTS: After gastroscopy, 109, 53 and 357 subjects were diagnosed as gastric ulcer, duodenal ulcer and non-ulcer subjects, respectively. Although, there were no significant differences of HSP70-2 genotype distributions among nonulcer subjects, overall ulcer, gastric and duodenal ulcers when the subjects were divided into two groups according to age distribution, logistic regression analysis showed that the BB genotype increased the risk of duodenal ulcer in subjects 60 years and older. (Gender, status of H. pylori infection and NSAID use adjusted OR=3.12, 95%CI=1.33-7.35, p=0.009). CONCLUSIONS: It appears that polymorphism of HSP70-2 gene is not directly associated with the susceptibility to peptic ulcer diseases but BB genotype is associated with an increased risk of duodenal ulcer in older subjects in the Japanese population.

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.

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.

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.

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 polymorphisms of IL-1ß 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-1ß and TNF-α genes, with CIHM status in the nonneoplastic gastric mucosa. Polymorphisms in the IL-1ß 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-1ß-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-1ß-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-1ß-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.

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

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 study of common genetic variants in pre-microRNAs in patients with ulcerative colitis.

BACKGROUND: Common single-nucleotide polymorphisms (SNPs) in microRNAs (miRNA) have been shown to be associated with susceptibility to several human diseases. 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 ulcerative colitis (UC) in a Japanese population. METHODS: The rs11614913 (T > C), rs2910164 (C > G), and rs3746444 (A > G) SNPs were genotyped in 170 UC and 403 control subjects. RESULTS: The rs3746444 AG genotype was significantly higher among the UC group (odds ratio (OR) = 1.51, 95% CI = 1.03-2.21, p = 0.037). The rs3746444 AG genotype was associated with onset at an older age (OR = 1.70, 95% CI = 1.04-2.78, p = 0.035), left-sided colitis and pancolitis (left-sided colitis, OR = 2.10, 95% CI = 1.12-3.94, p = 0.024; pancolitis, OR = 1.81, 95% CI = 1.09-3.01, p = 0.028, left-sided colitis + pancolitis, OR = 1.91, 95% CI = 1.26-2.92, p = 0.003), higher number of times hospitalized (OR = 2.63, 95% CI = 1.22-5.69, p = 0.017), steroid dependence (OR = 2.63, 95% CI = 1.27-5.44, p = 0.014), and refractory phenotypes (OR = 2.76, 95% CI = 1.46-5.21, p = 0.002) while the rs3746444 AA genotype was inversely associated with the number of times hospitalized (2∼, OR = 0.36, 95% CI = 0.17-0.79, p = 0.012), steroid dependence (OR = 0.42, 95% CI = 0.21-0.88, p = 0.021), and refractory phenotypes (OR = 0.38, 95% CI = 0.20-0.72, p = 0.003). The rs1161913 TT genotype also held a significantly higher risk of refractory phenotype (T/T vs. T/C + C/C, OR = 2.21, 95% CI = 1.17-4.18, p = 0.016). CONCLUSIONS: Our results provided the first evidence that rs3746444 SNP may influence the susceptibility to UC, and both rs3746444 and rs11614913 SNPs may influence the pathophysiological features of UC.

Gastrointestinal Stromal Tumor of the Stomach with Narrow Stalk-Like Based, Uneven Protruding Appearance Presenting with Severe Acute Anemia despite Small Size.

We report the case of a 56-year-old woman who had a gastrointestinal stromal tumor (GIST) of the stomach. She was admitted to our hospital for epigastric pain, nausea, and severe acute anemia (hemoglobin level 4.3 g/dl). Esophagogastroduodenoscopy revealed a narrow stalk-like based, hemorrhagic and uneven protruding lesion in the lesser curvature of the gastric upper corpus. Although the tumor was less than 2 cm in diameter and was probably a benign GIST according to histology, laparoscopy-assisted local resection was needed because the patient had continuous severe anemia and epigastric pain. Histological assessment showed that the elongated spindle-like tumor cells originated from the intrinsic muscle layer, and was shown with growth to the mucosal side, cropping out to the surface in most areas of the protruding lesion. Only a small part of the tumor was within nontumoral gastric mucosa. Most of the tumor cells demonstrated immunoreactivity for KIT and CD34 in the cytoplasm but not for αSMA, S100, and desmin. Mitotic activity (0/50 high power field) and the labeling index for MIB-1 (about 1%) were low. The GIST of the stomach described in this report was a rare case with a narrow stalk-like based, uneven protruding mass presenting with severe acute anemia despite small size.

Association between cyclin D1 polymorphism with CpG island promoter methylation status of tumor suppressor genes in gastric cancer.

BACKGROUND: CpG island hypermethylation of tumor suppressor genes is highly involved in gastric carcinogenesis, and enhanced cell proliferation could accelerate this process. Cyclin D1 regulates cell cycle function and may play a role in methylation-related carcinogenesis. AIMS: We investigated the association between Cyclin D1 gene G870A polymorphism and the methylation status of tumor suppressor genes in gastric cancer. METHODS: Polymorphisms at G870A in the Cyclin D1 gene were genotyped, and methylation status of the p14, p16, DAP-kinase, and CDH1 genes were determined by methylation-specific-polymerase chain reaction in 139 gastric cancer tissues. CIHM high was defined as three or more methylated CpG islands. RESULTS: Although no association was found between methylation status and different stages and Lauren's subtypes, patients with CIHM of DAP-kinase showed significantly worse survival than those without (p = 0.017). In addition, the number of methylated sites was also associated with survival curves (p = 0.0397). The 870G carrier a significantly lower prevalence of CIHM high compared to the AA genotype in advanced-stage gastric cancer (adjusted OR = 0.32, p = 0.047). A weak correlation between the same genotypes and CIHM of p14 were found in the same subtype (adjusted OR = 0.32, p = 0.052). The mean methylation number was significantly lower in G carriers than in AA genotypes in advanced-stage gastric cancer (p = 0.017). CONCLUSIONS: Genetic polymorphism of CCND1 is associated with CIHM status in gastric cancer, especially in the advanced stage, but is independent of clinico-pathological features.

CpG island promoter methylation (CIHM) status of tumor suppressor genes correlates with morphological appearances of gastric cancer.

UNLABELLED: CpG island hypermethylation (CIHM) of tumor suppressor genes is one of the major events in the gastric carcinogenesis. We aimed to investigate the association between CIHM status of tumor suppressor genes and clinicopathological and morphological characteristics of gastric cancer. PATIENTS AND METHODS: CIHM of p14, p16, Death-associated protein kinase (DAPK) and E-cadherin (CDH1) genes were determined by methylation-specific-polymerase chain Reaction in 146 gastric cancer tissues. CIHM-high was defined as three or more methylated CpG islands. RESULTS: CIHM pf p14 was found in 70 (47.9%) cases, in 26 (17.8%) for p16, in 104 (71.2%) for CDH1 and in 127 (87.0%) for DAPK. CIHM-high was also found in 63 cases (43.2%). No association was found between between CIHM status and different staging, Lauren's subtypes, anatomic location, venous and lymphatic invasion, lymph node metastasis, distant metastasis, or peritoneal dissemination. However, among early gastric cancer cases, the depressed type with ulceration presented a significantly lower prevalence of CIHM of DAPK. In addition, Borrmann type IV cases presented significantly lower prevalence of CIHM-high among advanced gastric cancer. The Borrmann type IV cases also presented lower mean methylation number. CONCLUSION: The present results suggest that CIHM of DAPK and CIHM-high were associated with the morphological appearance of depressed type with ulceration in early gastric cancer, and Borrmann type IV advanced gastric cancer, respectively.

Increased number of CpG island hypermethylation in tumor suppressor genes of non-neoplastic gastric mucosa correlates with higher risk of gastric cancer.

BACKGROUND/AIM: We investigated the relationship of gastric cancer (GC) and CpG island hypermethylation (CIHM) in tumor suppressor genes of non-neoplastic gastric mucosa. METHODS: Gastric mucosa samples were obtained from 125 GC and 180 non-GC subjects. CIHM of p14, p16, DAP-kinase and CDH1 genes were determined by methylation-specific polymerase chain reaction. High CIHM was defined as three or all methylated CpG islands. RESULTS: Rates of CIHM of p14, CDH1, DAP-kinase, and high CIHM were significantly higher in all GC samples than non-GC samples (p14: 32.2 vs. 50.4%; OR = 1.70, 95% CI = 1.03-2.80, p = 0.04, CDH1: 36.1 vs. 84.0%; OR = 8.65, 95% CI = 14.74-15.77, p < 0.0001, DAP-kinase: 42.2 vs. 83.2%; OR = 5.98, 95% CI = 3.37-10.62, p < 0.0001, and high CIHM: 44.4 vs. 80.8%; OR = 4.40, 95% CI = 2.51-7.72, p < 0.0001). CIHM in CDH1 and DAP-kinase were associated with a greater risk of GC including all of its different subtypes. An increased number of CIHM was associated with an increased risk of all GC (1 CIHM; OR = 2.33, 95% CI = 0.82-6.64, p = 0.11, 2 CIHM; OR = 4.89, 95% CI = 1.79-13.37, p = 0.002, 3 CIHM; OR = 9.43, 95% CI = 3.20-27.78, p < 0.0001, and all CIHM OR = 24.71, 95% CI = 6.70-91.18, p < 0.0001). Three and all CIHM were closely associated with a higher risk of intestinal-type GC, Helicobacter pylori-positive infection status, male gender, and middle and older GC while 3 CIHM was closely associated with a higher risk of diffuse-type GC, H. pylori-negative infection status and younger GC. CONCLUSIONS: CIHM of CDH1 and DAP-kinase in non-neoplastic gastric mucosa corresponded to a risk of GC regardless of histological subtype, H. pylori infection status, gender and generation. An increased number of CIHM correlates with a higher GC risk including its various clinico-pathological subtypes.

Association between IL-17A, -17F and MIF polymorphisms predispose to CpG island hyper-methylation in gastric cancer.

CpG island hyper-methylation (CIHM) is one of the major events in the gastric carcinogenesis. IL-17A, -17F and MIF have a crucial role in the gastric inflammation and carcinogenesis. Recently, we showed that the genetic polymorphisms of MIF-794-CATT repeat are associated with CIHM status in the non-neoplastic gastric mucosa. Consequently, the CIHM status in the gastric cancer tissue, in relation to IL-17A (-197G>A), -17F (7488T>C), and MIF (-173G>C and -794 tetranucleotide repeats) polymorphisms was investigated. Gastric cancer tissues were obtained from 102 patients. CIHM of p14, p16, DAP-kinase and CDH1 genes were determined by methylation-specific polymerase chain reaction (MSP). CIHM high was defined as three or all CpG islands methylated. We employed the PCR-SSCP (multiplex PCR for IL-17A and -17F) method to detect the gene polymorphisms. We did not find significant association between CIHM status and IL-17F (7488T>C) and MIF (-173G>C) polymorphisms. However, concerning the IL-17A (-197G>A) polymorphism, we found that IL-17A G carrier (GG+GA) held a significantly higher risk of CIHM of p16 (OR=11.22, 95% CI=1.38-91.17, p=0.024) and CIHM high (OR=3.51, 95% CI=1.15-10.68, p=0.027). An association was also found between the 7-CATT repeat carrier (5/7 + 6/7 + 7/7) of the MIF polymorphism (-794-CATT) and reduced risk of CIHM of CDH1 (OR=0.36, 95% CI=0.14-0.92, p=0.032). No association was found between CHIM status and homozygote genotypes of each repeat (-794-CATT 5/5, 6/6, and 7/7). The present results provided evidence that the genetic polymorphisms of IL-17A, and MIF-794-CATT repeat are associated with CIHM status in the gastric cancer. Genetic polymorphisms of IL-17A, and MIF-794-CATT repeat may be involved in methylation-related carcinogenesis in the stomach.

Vitamin E protects against stress-induced gastric mucosal lesions in rats more effectively than vitamin C.

In this study, we examined the protective effects of vitamin E (VE) against gastric mucosal lesions induced by water immersion restraint stress (WIRS) in rats in comparison with that of vitamin C (VC). The gastric mucosa of rats with 6 h of WIRS showed lesions with bleeding, decrease in nonprotein SH, VC, VE, and adherent mucus concentrations and constitutive nitric oxide synthase activity, and increase in lipid peroxide and NOx (nitrite/nitrate) concentrations and myeloperoxidase, xanthine oxidase, and inducible nitric oxide synthase activities. Either VE (0.05 or 0.5 mmol/kg) or VC (0.5 or 1.5 mmol/kg) was orally administered to rats with 6 h of WIRS just before the onset of the stress. Both doses of pre-administered VE prevented gastric mucosal lesion development and attenuated all these changes in gastric mucosal components and enzymes studied, whereas only the higher dose of pre-administered VC suppressed the changes in all parameters studied. These results indicate that orally administered VE protects against WIRS-induced gastric mucosal lesions in rats more effectively than orally administered VC. These results also suggest that the administered VE protects against gastric mucosal lesions in rats with WIRS through its antioxidant and anti-inflammatory actions in the gastric mucosa in the same way as the administered VC.

Association between common genetic variants in pre-microRNAs and the clinicopathological characteristics and survival of gastric cancer patients.

Common single-nucleotide polymorphisms (SNPs) in microRNAs (miRNAs) have been shown to be associated with susceptibility to several types of human cancer. We evaluated the association between three SNPs (rs11614913, rs2910164 and rs3746444) in pre-miRNAs (miR-196a2, miR-146a and miR-499) and various clinicopathological characteristics, including CpG island hypermethylation (CIHM) status and overall survival in gastric cancer (GC) patients. rs11614913 (T>C), rs2910164 (C>G) and rs3746444 (A>G) SNPs were genotyped in 127 GC patients. CIHM of p14, p16, DAP-kinase and CDH1 genes was determined by methylation-specific polymerase chain reaction in the cancer tissues. A significant marginal association was found between the rs11614913 CC genotype and polypoid or elevated type morphology in early-stage GC (OR=6.29, 95% CI 1.18-33.47, p=0.03). The rs2910164 CC and CG genotypes were associated with increased susceptibility to CIHM of DAP-kinase (CC+CG, OR=5.48, 95% CI 1.30-23.10, p=0.02; CC, OR=6.93, 95% CI 1.37-35.02, p=0.02; CG, OR=4.24, 95% CI 0.87-20.78, p=0.07). The 11614913 TT and TC genotypes were associated with a higher number of CIHM (no. of CIHM 0-1 vs. 2-4; TT+TC, OR=3.67, 95% CI 0.98-13.72, p=0.05; TC, OR=4.08, 95% CI 1.04-15.97, p=0.04). When the subjects were divided according to age group, the combined rs11614913 TT+TC genotype tended to be associated with worse overall survival than the CC genotype in patients younger than 65 years of age (p=0.05). The combined rs2910164 CG+GG genotype also tended to be associated with worse overall survival than the CC genotype in the same age group (p=0.09). It appears that rs11614913 and rs2910164 SNPs in pre-miRNAs (miR-196a2 and miR-146a) affect the clinicopathological characteristics of GC, including its morphological appearance, CIHM status and overall survival.

Chronic aspirin use suppresses CDH1 methylation in human gastric mucosa.

There have been reports showing a protective role of aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) against gastrointestinal cancers. E-cadherin (CDH1) is an adhesion molecule involved in tumour invasion/metastasis. Silencing of CDH1 by promoter CpG island methylation was shown in gastric cancer, precancerous lesion, and Helicobacter pylori-infected chronic gastritis. We investigated the methylation status of CDH1 in noncancerous gastric mucosa in chronic aspirin user, and assessed its effect on methylation-associated carcinogenesis. Gastric mucosa samples from antrum were obtained from 217 cancer-free subjects, including 37 chronic aspirin users and 180 subjects with no history of chronic or occasional intake of aspirin. Methylation-specific polymerase chain reaction (PCR), i.e., MSP, was performed for CDH1 gene promoter. In all 217 subjects, CDH1 methylation was detected for 69 subjects (31.7%). CDH1 methylation more frequently occurred in H. pylori-infection-positive subjects (P < 0.0001), while chronic aspirin users had a significantly lower risk of CDH1 methylation [nonuser versus user 36.1% versus 10.8%; odds ratio (OR) = 0.21, 95% confidence interval (CI) = 0.07-0.63, P = 0.005]. Logistic regression analysis showed that chronic aspirin use was the independent factor for lower risk of CDH1 methylation (adjusted OR = 0.21, 95%CI = 0.07-0.66, P = 0.008). Chronic aspirin use was associated with lower risk of CDH1 methylation in H. pylori-positive subjects (nonuser versus user 49.5% versus 19.0%; OR = 0.24, 95%CI = 0.08-0.76, P = 0.01). Similar trend was also found in H. pylori-negative subjects (P = 0.07). No association was found between CDH1 methylation status, and duration and dose of aspirin. Our data suggest that chronic aspirin use is associated with reduced risk of CDH1 methylation in human gastric mucosa. Aspirin may have suppressive role against methylation-related gastric carcinogenesis.