Non-metaplastic Mucosa Research Articles

Helicobacter pylori Eradication Reverses DNA Damage Response Pathway but Not Senescence in Human Gastric Epithelium.

Helicobacter pylori (H. pylori) infection induces DNA Double-Strand Breaks (DSBs) and consequently activates the DNA Damage Response pathway (DDR) and senescence in gastric epithelium. We studied DDR activation and senescence before and after the eradication of the pathogen. Gastric antral and corpus biopsies of 61 patients with H. pylori infection, prior to and after eradication treatment, were analyzed by means of immunohistochemistry/immunofluorescence for DDR marker (γH2AΧ, phosporylated ataxia telangiectasia-mutated (pATM), p53-binding protein (53BP1) and p53) expression. Samples were also evaluated for Ki67 (proliferation index), cleaved caspase-3 (apoptotic index) and GL13 staining (cellular senescence). Ten H. pylori (-) dyspeptic patients served as controls. All patients were re-endoscoped in 72-1361 days (mean value 434 days), and tissue samples were processed in the same manner. The eradication of the microorganism, in human gastric mucosa, downregulates γH2AΧ expression in both the antrum and corpus (p = 0.00019 and p = 0.00081 respectively). The expression of pATM, p53 and 53BP1 is also reduced after eradication. Proliferation and apoptotic indices were reduced, albeit not significantly, after pathogen clearance. Moreover, cellular senescence is increased in H. pylori-infected mucosa and remains unaffected after eradication. Interestingly, senescence was statistically increased in areas of intestinal metaplasia (IM) compared with adjacent non-metaplastic mucosa (p < 0.001). In conclusion, H. pylori infection triggers DSBs, DDR and senescence in the gastric epithelium. Pathogen eradication reverses the DDR activation but not senescence. Increased senescent cells may favor IM persistence, thus potentially contributing to gastric carcinogenesis.

Ultra-magnifying narrow-band imaging for endoscopic diagnosis of gastric intestinal metaplasia: a pilot image analysis study.

Background and study aims Narrow-band imaging (NBI) with or without magnification has recently been used for diagnosis of gastric intestinal metaplasia (GIM). Endocytoscopy is a newly developed endoscopic technique that enables ultra-high (500 ×) magnification of the digestive tract mucosa. This study aimed to analyze the ultra-magnifying NBI characteristics of GIM. Patients and methods This was a retrospective observational study conducted in a cancer referral center. Patients who underwent ultra-magnifying NBI of the gastric mucosa using endocytoscopy were eligible. A soft black cap was used for non-contact observation. We compared the characteristic findings of GIM by ultra-magnifying NBI of metaplastic and non-metaplastic mucosae. A reference standard for GIM in this study was conventional magnifying NBI findings of GIM. Results We obtained 28 images of metaplastic mucosa and 32 of non-metaplastic mucosa from 38 patients. Ultra-magnifying NBI revealed the cobblestone-like cellular structure in the marginal crypt epithelium of metaplastic and non-metaplastic mucosa. Diagnostic values (sensitivity, specificity, accuracy and kappa value [95 % confidence interval]) for the heterogeneous cellular structure and rough contour of the marginal crypt epithelium were 82 % (68 %–96 %), 94 % (85 %–100 %), 88 % (80 %–96 %), and 0.70, and 86 % (73 %–99 %), 94 % (85 %–100 %), 90 % (82 %–98 %), and 0.71, respectively. Conclusions The characteristic ultrastructural features of GIM were identified by ultra-magnifying NBI, warranting validation of diagnostic value in a prospective study.

Significance of HER2 and Ki-67 in Preneoplastic Lesions and Carcinoma of Gallbladder.

HER2 is an oncoprotein which is overexpressed in several cancers including breast and stomach. Several studies have shown that HER2 is overexpressed in gallbladder cancer and in precancerous lesions. The present study was undertaken to assess pattern and level of expression of HER2 in metaplasia, dysplasia, and different stages of gallbladder carcinoma, which would determine its suitability as a prognostic biomarker in neoplastic transformation of gallbladder epithelium. The study was also aimed at to find the significance of Ki-67 index in these lesions. One hundred and twenty-eight patients who underwent cholecystectomy comprised the study group. Among them, 108 (84.4%) specimens showing metaplasia, dysplasia, and carcinoma on routine histopathology were considered as cases and 20 (15.6%) specimens of chronic cholecystitis having non-metaplastic mucosa were considered as control. Immunohistochemistry (IHC) was performed for HER2 and Ki-67. For HER2 interpretation ASCO/CAP guideline for breast cancer was followed. Chi-square test was used to find out the significance of HER2 expression in dysplasia/metaplasia/carcinoma. The ANOVA and Tukey-Kramer Multiple Comparisons Test were used for determining the association of Ki-67 with malignant transformation. Overexpression of HER2 was observed in 48% (n = 12) of adenocarcinomas, 58% (n = 7) of high-grade dysplasia, 47% (n = 8) of low-grade dysplasia, and 74% (n = 25) of intestinal metaplasia. Ki-67 index increases in a non-linear fashion as the precursor lesions progress toward malignancy. In the future, these markers might be used as a prognostic biomarker for gallbladder carcinoma and its precursor lesions and it might become a valid indication for targeted therapies for gallbladder cancer.

High-definition CpG methylation of novel genes in gastric carcinogenesis identified by next-generation sequencing

Gastric cancers are the most frequent gastric malignancy and usually arise in the sequence of Helicobacter pylori-associated chronic gastritis. CpG methylation is a central mechanism of epigenetic gene regulation affecting cancer-related genes, and occurs early in gastric carcinogenesis. DNA samples from non-metaplastic gastric mucosa with variable levels of gastritis (non-metaplastic mucosa), intestinal metaplasia, or gastric cancer were screened with methylation arrays for CpG methylation of cancer-related genes and 30 gene targets were further characterized by high-definition bisulfite next-generation sequencing. In addition, data from The Cancer Genome Atlas were analyzed for correlation of methylation with gene expression. Overall, 13 genes had significantly increased CpG methylation in gastric cancer vs non-metaplastic mucosa (BRINP1, CDH11, CHFR, EPHA5, EPHA7, FGF2, FLI1, GALR1, HS3ST2, PDGFRA, SEZ6L, SGCE, and SNRPN). Further, most of these genes had corresponding reduced expression levels in gastric cancer compared with intestinal metaplasia, including novel hypermethylated genes in gastric cancer (FLI1, GALR1, SGCE, and SNRPN), suggesting that they may regulate neoplastic transformation from non-malignant intestinal metaplasia to cancer. Our data suggest a tumor-suppressor role for FLI1 in gastric cancer, consistent with recently reported data in breast cancer. For the genes with strongest methylation/expression correlation, namely FLI1, the expression was lowest in microsatellite-unstable tumors compared with other gastric cancer molecular subtypes. Importantly, reduced expression of hypermethylated BRINP1 and SGCE was significantly associated with favorable survival in gastric cancer. In summary, we report novel methylation gene targets that may have functional roles in discrete stages of gastric carcinogenesis and may serve as biomarkers for diagnosis and prognosis of gastric cancer.

The different expression of carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) and possible roles in gastric carcinomas

The purpose of this study was to investigate the expression of carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) and its effects on promoting angiogenesis in gastric adenocarcinomas. Paraffin wax sections of 222 patients with gastric adenocarcinomas having undergone surgery between 2001 and 2006 were classified into three histotypes: intestinal, diffuse, and mixed carcinomas following the Laurén classification. Immunohistochemistry (IHC) was used to study the distribution of CEACAM1, and double-labeling immunohistochemistry was used to observe the relationship between CEACAM1 expression and neovascularization in carcinoma areas. No CEACAM1 expression was found in normal non-metaplastic mucosa adjacent to the tumors; but in metaplastic mucosa, CEACAM1 was expressed on the apical surface. However, all of the collected gastric carcinomas expressed CEACAM1 with cytoplasmic or membranous staining. CEACAM1 was expressed mainly with a membranous pattern in the intestinal carcinomas, and with a cytoplasmic pattern in the diffuse carcinomas. There was a significant difference between the expression patterns and the histotypes ( P<0.0001). CEACAM1 expression was classified as high (⩾66% positive cells) and low (<66% positive cells), and high CEACAM1 expression was associated with lymph nodes metastasis ( P<0.05). High microvessel density (MVD) was observed more frequently in the tumors with membranous expression, and low MVD in the tumors with cytoplasmic staining ( P<0.0001). The transformation of CEACAM1 distribution from membrane to cytoplasm is an important incident for the reverse effects on the tumorous angiogenesis, and high expression of CEACAM1 facilitates the metastasis of carcinoma cells to lymph nodes. Moreover, the different distribution of CEACAM1 in the intestinal and diffuse carcinomas indicates a different tumorigenic pathway.

Id-1gene downregulation by sulindac sulfide and its upregulation during tumor development in gastric cancer

The molecular mechanisms underlying the chemopreventive effects of NSAIDs are not well understood and remain the subject of debate. One of the mechanistic possibilities involves alterations in gene expression. We examined gene expression profiles in SNU601 gastric cancer cells treated with sulindac sulfide (50 microM) for 24 hr. Microarray analysis showed that 1.3% (105/8170) of genes were induced or repressed more than 3-fold in cells treated with sulindac sulfide. Seven genes were selected and confirmed by reverse transcription-polymerase chain reaction. Inhibitor of differentiation/DNA binding-1 (Id-1) was downregulated in SNU601 cells treated with sulindac sulfide. Id-1 expression level was decreased dose-dependently by sulindac sulfide. In addition, the expression pattern of Id-1 was inversely related to that of nm23. We also examined Id-1 expression in human gastric cancer tissues and compared it with clinicopathologic parameters to study its biologic role in the cancers. Id-1 was frequently and strongly expressed in gastric cancer tissues compared with that in adjacent nonmetaplastic mucosa. Its immunoreactivity scores were positively correlated to Ki67 labeling indices and tumor progression, and is higher in intestinal type than in diffuse type. In summary, a number of genes, both induced and repressed, could be important in mediating sulindac sulfide-induced cell death in gastric cancer cells. Id-1, one of the repressed genes, is upregulated in gastric cancers and has positive role in tumor progression and histogenesis of intestinal-type cancers.

Effect of Helicobacter pylori eradication on epithelial cell turnover and p53 expression of the gastric mucosa in patients with chronic gastritis-comparison between intestinal metaplastic and non-metaplastic mucosa

Effect of Helicobacter pylori eradication on epithelial cell turnover and p53 expression of the gastric mucosa in patients with chronic gastritis-comparison between intestinal metaplastic and non-metaplastic mucosa

Effect of Helicobacter pylori eradication on epithelial cell turnover and p53 expression of the gastric mucosa in patients with chronic gastritis-comparison between intestinal metaplastic and non-metaplastic mucosa

Effect of Helicobacter pylori eradication on epithelial cell turnover and p53 expression of the gastric mucosa in patients with chronic gastritis-comparison between intestinal metaplastic and non-metaplastic mucosa

Mucosal expression of carcinoembryonic antigen and carbohydrate antigen 19-9 in patients with gastritis and gastric cancer.

Sixty-eight patients (45 males, 23 females) were studied in order to assess the usefulness of mucosal tissue concentrations of both carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) in detecting patients at high risk for gastric cancer. CEA and CA19-9 were assayed on cytosol obtained from multiple endoscopic biopsies of 41 patients with chronic superficial gastritis, 18 with chronic atrophic gastritis, and 9 with gastric cancer. Mucosal tissue concentrations of both CEA and CA19-9 increased from chronic superficial gastritis to chronic atrophic gastritis and to gastric cancer (p = 0.005 and p = 0.002, respectively). Mucosal CEA levels in patients with intestinal metaplasia (IM) were significantly higher than in nonmetaplastic mucosa (p = 0.04). Epithelial dysplasia was associated with higher, though not significant, tissue concentrations of both CEA and CA19-9 when compared with IM. Finally, a correlation between serum levels and tissue concentrations was observed only for CA19-9 (Pearson's correlation coefficient = 0.7). In conclusion, these data indicate that gastric mucosa of patients with chronic atrophic gastritis and intestinal metaplasia express high levels of both CA19-9 and CEA.

Gastric metaplasia in duodenal ulcer. Histochemical considerations of its pathophysiological significance.

Gastric metaplasia of the duodenal mucosa in biopsy specimens of healed duodenal ulcer and in surgical specimens of perforated duodenal ulcer was investigated using mucin histochemistry and the indirect immunoperoxidase method. Endoscopic methylene blue test was performed prior to biopsy. All specimens from areas showing no dye absorption revealed varying degrees of gastric metaplasia characterized by heterotopic occurrence of gastric-type foveolar cells mainly at the tips of stunted intestinal villi. On average, 31.8% of the total surface length of duodenal mucosa taken from areas showing no dye absorption was occupied by the metaplastic cells. They showed strong reactivities for periodic acid-Schiff (PAS) and galactose oxidase-Schiff sequences, while alcian blue and paradoxical concanavalin A staining, class III, were negative. Immunoperoxidase-PAS double staining revealed a few gastrin and somatostatin cells in foci of gastric metaplasia, but almost no cells containing motilin, secretin, cholecystokinin and gastric inhibitory peptide. Such endocrine cells were scattered in nonmetaplastic mucosa. While such metaplastic change has been regarded as a self-defence mechanism or adaptation of the duodenal mucosa against acid, a local decrease of normal endocrine cells, which allegedly function as acid receptors, may lead to alterations of gastroduodenal interaction. It is suggested that gastric metaplasia is important as one of the pathophysiological mechanisms involved in the recurrence of duodenal ulcer.

Gastric ulcer and carcinoma in fundic gland area.

The gastric ulcer and carcinoma in the fundic gland area were investigated with the surgically resected cases. 1. The frequency of the ulcer in the fundic gland area was 8.2% of 2194 cases of gastric ulcer and that of carcinoma in this area was 8.4% of 780 cases of gastric carcinoma. These two diseases showed high frequency in the age group of forty to fifty years withpreponderance in female. 2. The ulcers in the fundic gland area usually showed high acidity and high frequency of massive bleeding like as melena and hematemesis comparing with other lesions or the ulcers in other sites. 3. The ratio of the low-differentiated carcinomas to the well-differentiated ones was about 3.7 to 1 in the fundic gland area and 1 to 1.3 in the pyrolic gland area. 4. The frequency of the early gastric carcinomas was 27% and 41% in the fundic and pyrolic gland areas, respectively. 5. In the fundic gland area, as observed in the pyrolic gland area, the low-differentiated carcinomas usually occurred on the non-metaplastic mucosa and the majority of well-differentiated ones were frequently found in association with the intestinal metaplasia. 6. Although the solitary carcinoma in the anterior wall or greater curvature was found not infrequently, the solitary ulcer was not found in these sites in this series.

THE RELATIONSHIP OF GASTROINTESTINAL ENDOCRINE CELLS TO GASTRIC EPITHELIAL CHANGES WITH SPECIAL REFERENCE TO GASTRIC CANCER

Using advanced gastric adenocarcinoma and carcinoid as human material and gastric adenocarcinoma in rats induced by MNNG and in mice by localized X-irradiation of the stomach as experimental material, a pathological study was made on the relationship of gastric endocrine cells to gastric cancer. The results of the present study suggest that most of the endocrine cells in the cancer tissue are derived from the differentiation of cancer cells. Therefore, the following three may be given as the aformentioned relationship, that is, 1) carcinoid of endocrine cell origin, 2) endocrine cell carcinoma showing undifferentiated adenocarcinoma, and 3) endocrine cell cloning developed from the differentiation of cancer cell of adenocarcinoma. There is the possibility that most of 2) are of 3) origin and thus 2) and 3) should be discriminated from 1), having a functioning tumor in rare cases. The significance of reactive hyperplasia of endocrine cells in the non-metaplastic mucosa of the stomach around cancer and atypical epithelium is not yet determined, but that of EC cell seems at least to be related with the development of intestinal metaplasia in the gastric mucosa.