Expression and significance of Tie-1 and Tie-2 receptors, and angiopoietins-1,2 and 4 in colorectal adenocarcinoma:Immunohistochemical analysis and correlation with clinicopathological factors

AIM: There is strong evidence that tyrosine kinases are involved in the regulation of tumor progression, cellular growth and differentiation. Recently, many kinds of tyrosine kinase receptors have been reported, among them Tie-1 and Tie-2 receptors constitute a major class.Angiopoietin (Ang)-1 is known as a ligand ofTie-2 tyrosine kinase receptor. The objective of this study was to establish a comprehensive Tie-1 and Tie-2 and Ang-1, 2 and 4expression profile in human colorectal adenocarcinomas.METHODS: We examined 96 cases of surgically resected human colorectal adenocarcinoma by immunohistochemistry and investigated the statistical correlation between the expressions of Ties and Angs and clinicopathological factors.RESULTS: Among the 96 cases of adenocarcinoma, 87(90.6%), 92 (95.8%), 83 (86.5%), 89 (92.7%), and 76cases (79.2%) showed positive staining in the cytoplasm of carcinoma cells for the Tie-1 and Tie-2 and Ang-1, 2and 4 proteins, respectively. Histologically, the expressions of Ties and Angs were variable. The expressions of Ties and Angs were correlated with several clinicopathological factors, but did not correlate with the presence of lymph node metastasis. Ties and Angs were highly expressed in human colorectal adenocarcinoma cells.CONCLUSION: These findings suggest that the Tie-Ang receptor-ligand complex is one of the factors involved in the cellular differentiation and progression of human colorectal adenocarcinoma.

Expression of mucosal addressin cell adhesion molecule 1 on vascular endothelium of gastric mucosa in patients with nodular gastritis

AIM:The interaction of mucosal addressin cell adhesion molecule 1 (MAdCAM-1) with integrin α4β7 mediates lymphocyte recruitment into mucosa-associated lymphoid tissue (MALT).Nodular gastritis is characterized by a unique military pattern on endoscopy representing increased numbers of lymphoid follicles with germinal center,strongly associated with H pylori infection.The purpose of this study was to address the implication of the MAdCAM-1/integrin β7 pathway in NG. METHODS:We studied 17 patients with NG and H pylori infection and 19 H pylori-positive and 14 H pylori-negative controls.A biopsy sample was taken from the antrum and snap-frozen for immunohistochemical analysis of MAdCAM- 1 and integrin β7.In simultaneous viewing of serial sections, the percentage of MAdCAM-1-positive to von Willebrand factor-positive vessels was calculated.We also performed immunostaining with anti-CD20,CD4,CD8 and CD68 antibodies to determine the lymphocyte subsets co- expressing integrin β7. RESULTS:Vascular endothelial MAdCAM-1 expression was more enhanced in gastric mucosa with than without H pylori infection.Of note,the percentages of MAdCAM-1-positive vessels were significantly higher in the lamina propria of NG patients than in H pylori-positive controls.Strong expression of MAdCAM-1 was identified adjacent to lymphoid follicles and dense lymphoid aggregates.Integrin β7-expressing mononuclear cells,mainly composed of CD20 and CD4 lymphocytes,were associated with vessels lined with MAdCAM-1-expressing endothelium.CONCLUSION: Our results suggest that the MAdCAM一1/ integrin a4p7 homing system may participate in gastric inflammation in response to H py/o}i-infection and contributes to MALT formation, typically leading to the development of NG.

Impact of endoscopically minimal involvement on IL-8 mRNA expression in esophageal mucosa of patients with non-erosive reflux disease

AIM:Little has been known about the pathogenesis of non- erosive reflux disease(NERD).Recent studies have implicated interleukin 8(IL-8)in the development and progression of gastroesophgeal reflux disease(GERD).The purpose of this study was to determine IL-8 RNA expression levels in NERD patients with or without subtle mucosal changes. METHODS:We studied 26 patients with NERD and 13 asymptomatic controls.Biopsy sample was taken from the esophagus 3 cm above the gastroesophageal junction and snap frozen for measurement of IL-8 mRNA levels by real-time quantitative polymerase chain reaction(PCR).We also examined mRNA expression of IL-8 receptors,CXCR-1 and -2 by reverse transcriptase PCR.The patients were endoscopically classified into grade M(mucosal color changes without visible mucosal break)and N(neither minimal involvement nor mucosal break)of the modified Los Angeles classification. RESULTS:The relative IL-8 mRNA expression levels were significantly higher in esophageal mucosa of NERD patients than those in esophageal mucosa of the controls.There was a significant difference in IL-8 mRNA levels between grades M and N.The CXCR-1 and -2 mRNAs were constitutively expressed in esophageal mucosa.CONCLUSION: Our results suggest that high IL-8 levels in esophageal mucosa may be involved in the pathogenesis of NERD through interaction with its receptors. NERD seems to be composed of a heterogeneous population in terms of not only endoscopically minimal involvement but also immune and inflammatory processes.

Impact of Helicobacter pylori infection on ghrelin and various neuroendocrine hormones in plasma

AIM: Ghrelin, an endogenous ligand for growth hormone secretagogue receptor, influences appetite, energy balance, gastric motility and acid secretion. The stomach is the main source of circulating ghrelin. There are inconsistent reports on the influence of Helicobacter pylori (H pylori) infection on circulating ghrelin levels. We sought to elucidate the relationship between ghrelin and various peptides in plasma, with special reference to H pylori.METHODS: Plasma ghrelin levels were measured by radioimmunoassay in 89 subjects who were referred for upper gastrointestinal endoscopy, consisting of 42 H pylori infected and 47 uninfected ones. Plasma gastrin,somatostatin, leptin, insulin-like growth hormone 1 (IGF-1)and chromogranin A concentrations were also measured.Twelve patients were treated with anti- H pylori regimen.RESULTS: Ghrelin circulating levels were greatly decreased in H pylori-positive than negative individuals (194.2±90.2fmol/mL and 250.4±84.1 respectively, P＜0.05), but did not significantly alter following the cure of infection (176.5±79.5 vs 191.3±120.4). There was a significant negative correlation between circulating ghrelin and leptin levels, as well as body mass index, for the whole and uninfected population, but not in H pylori-infected patients. Plasma ghrelin concentrations correlated positively with IGF-1 in H pylori-negative group and negatively with chromogranin A in the infected group.There were no significant correlations among circulating levels of ghrelin, gastrin and somatostatin irrespective of H pylori status.CONCLUSION: H pylori infection influences plasma ghrelin dynamics and its interaction with diverse bioactive peptides involved in energy balance, growth and neuroendocrine function.

Epstein-Barr virus-associated gastric carcinoma in Kazakhstan

AIM: To investigate the incidence of Epstein-Barr virus-associated gastric cancer (EBV-GC) in Kazakhstan and to compare it with that in Russia, Western and Asian countries in order to evaluate the significance of epidemiopathologic and ethnic factors. METHODS: In situ hybridization (ISH) of EBV-encoded small RNA-1 (EBER-1) was used to identify the presence of EBER-1 signal in 139 formalin-fixed and paraffin-embedded GC tissues from Kazakhstan. RESULTS: EBER-1 expression was observed in the nuclei of 10% of the cases of GC (14/139), but not in the surrounding normal mucosa. The incidence of the diffuse type of EBV-GC was significantly higher in Kazakhstan (14%, 13/91) than that of the intestinal type (2%, 1/48). Furthermore, the incidence was significantly higher in males (14%, 12/89) than in females (3.7%, 2/53) from all countries. The overall incidence of EBV-GC increased from 6.7% in Asian countries to 8.7% in Russia, 10.1% in Kazakhstan and 16% in Western countries. CONCLUSION: Geographical differences in the incidence of EBV-GC may reflect the epidemiologic factors and/or dietary habits independent of histological type and sex.

Sofalcone, a mucoprotective agent, increases the cure rate of Helicobacter pylori infection when combined with rabeprazole, amoxicillin and clarithromycin

AIM: The mucoprotective agents, sofalcone and polaprezinc have anti-Helicobacter pylori ( H pylori)activities. We determined the therapeutic effects of sofalcone and polaprezinc when combined with rabeprazole,amoxicillin and clarithromycin for Helicobacter pylori infection.METHODS: One hundred and sixty-five consecutive outpatients with peptic ulcer and H pylori infection were randomly assigned to one of the following three groups and medicated for 7 d. Group A: triple therapy with rabeprazole (10 mg twice daily), clarithromycin (200 mg twice daily) and amoxicillin (750 mg twice daily). Group B: sofalcone (100 mg thrice daily) plus the triple therapy.Group C: polaprezinc (150 mg twice daily) plus the triple therapy. Eradication was considered successful if 13C-urea breath test was negative at least 4 wk after cessation of eradication regimens or successive famotidine in the cases of active peptic ulcer.RESULTS: On intention-to-treat basis, H pyloricure wasachieved in 43 of 55 (78.2%) patients, 47 of 54 (87.0%)and 45 of 56 (80.4%) for the groups A, B and Crespectively. Using per protocol analysis, the eradication rates were 81.1% (43/53), 94.0% (47/50) and 84.9% (45/53) respectively. There was a significant difference in the cure rates between group A and B. Adverse events occurred in 10, 12 and 11 patients, from groups A, B and C respectively, but the events were generally mild.CONCLUSION: The addition of sofalcone, but not polaprezinc, significantly increased the cure rate of H pylori infection when combined with the rabeprazole-amoxicillinclarithromycin regimen.

Expression of CXC receptor 1 and 2 in esophageal mucosa of patients with reflux esophagitis

AIM: Interleukin 8 (IL-8) mediates neutrophil trafficking via its receptors. Recent studies have shown that IL-8 is likely involved in the development and progression of erosive reflux esophagitis (RE), yet little is known about the two distinct receptors, CXC receptor (CXCR)-1 and -2.The purpose of this study was to determine CXCR-1 and -2 messenger RNA expression levels in RE.METHODS: We studied 26 patients with RE and 15asymptomatic controls. Paired biopsy samples were taken from the esophagus 3 cm above the gastroesophageal junction; one biopsy was snap frozen for measurement of CXCR-1 and -2 mRNA levels by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR), and another was formalin-fixed for histopathological evaluation.We also examined the association of the expression levels of CXCR-1 and -2 mRNA with histopathological hallmarks of RE.RESULTS: The relative CXCR-1 and -2 mRNA expression levels were rather decreased in esophageal mucosa of patients with RE, compared to those in normal esophagus of controls. There were no significant difference in the relative mRNA expression levels of CXCR-1 and -2 among endoscopic grades of RE based on the Los Angeles classification. Each histopathological hallmark of GERD was not associated with the expression levels of CXCR-1 and -2 mRNA.CONCLUSION: Apart from overexpression of IL-8, the relative expression levels of CXCR-1 and -2 mRNA were rather lower than expected in the affected esophageal mucosa of patients with RE.

Enhanced production of leptin in gastric fundic mucosa with Helicobacter pyloriinfection

AIM: To determine the concentrations of leptin in plasma and gastric fundic mucosa in humans, with reference to Helicobacterpylori (Hpylori) infection, and their association with gastric mucosal levels of interleukin (IL)-1β, IL-6 and IL-8, METHODS: Plasma leptin concentrations were determined in 135 outpatients with non-ulcer dyspepsia, consisting of 95 H pylori- infected and 40 uninfected subjects, and 13 patients before and after cure of the infection with anti-H pylori regimen. Using biopsy samples that were endoscopically obtained from the middle corpus along the greater curvature, gastric leptin contents were measured by radioimmunoassay and the mucosal concentrations of IL-Iβ, IL-6 and IL-8 were measured by enzyme linked immunosorbent assay. We also analysed the expression of leptin in the fundic mucosa by reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry. RESULTS: The mucosal levels of leptin in the fundic mucosa of H pylori-infected patients were significantly higher than those of uninfected patients. The amount of gastric leptin correlated positively with the mucosal levels of IL-1β and IL-6, but not IL-8. Circulating leptin correlated with body mass index, but not with H pylori status, and there was no change in plasma leptin levels following cure of the infection. Leptin immunoreactive cells were noted in the lower half of the fundic glands, and its expression of messenger ribonucleic acid in the oxyntic mucosa was detected by RT-PCR. CONCLUSION: Leptin production is enhanced in H pylori-infected gastric mucosa. Gastric leptin may be involved in immune and inflammatory response during H pylori infection, through interaction with proinflammatory cytokines.

Pedunculated rectal carcinoid removed by endoscopic mucosal resection: A case report

Carcinoid tumors generally appear as yellow/gray or tan submucosal nodules. We experienced a case of pedunculated rectal carcinoid showing a mushroom-like appearance. The case was a forty years old woman who was admitted to our hospital due to rectal bleeding. Colonoscopy revealed a pedunculated polyp presenting a mushroom-shaped appearance measuring 13 mm in diameter in the rectum.The histological diagnosis of specimens obtained by biopsy was adenocarcinoma and transanal ultrasonography revealed the tumor localization within the submucosal layer in the rectum. Endoscopic mucosal resection (EMR) was performed.Histopathological examination established the diagnosis of carcinoid tumor in the rectum. Frequencies of the pedunculated type in rectal carcinoids were reported to be 2.4 % to 7.1% in the literature. Because of its rarity,pedunculated configuration may confuse the endoscopic diagnosis of carcinoids. Treatment for carcinoids of 1 to 1.5 cm in size remains controversial. Although such tumors are technically respectable by EMR, careful attention must be paid in dealing with these tumors because there may be unexpected behaviors of the tumors.

Helicobacter pyloristrain-specific modulation of gastric inflammation in Mongolian gerbils

AIM: The cag pathogenicity island (PAI) is one of potential virulence determinants of Helicobacter pylori. The Mongolian gerbil is a suitable experimental animal for the screening of virulence factors of H pylori.METHODS: Five-week-old Mongolian gerbils were inoculated with a standard H pylori strain (ATCC 43504)possessing the cag PAI or a clinical isolate lacking the genes' cluster (OHPC-0002). The animals were killed at 2, 4, 8, 24 and 48 wk after inoculation (n = 5 each), and macroscopic and histopathological findings in the stomachs were compared.RESULTS: In gerbils infected with ATCC 43504, a more severe degree of infiltration of polynuclear and mononuclear cells and lymphoid follicles was observed from 4 wk after inoculation compared to gerbils infected with OHPC-0002 especially in the antrum and transitional zone from the fundic to pyloric gland area. In addition,glandular atrophy, intestinal metaplasia, gastric ulcer and hyperplastic polyps were noted in gerbils infected with ATCC 43504, whereas only mild gastric erosions occurred in those infected with OHPC-0002.CONCLUSION: Our results indicate that the cag PAI could be directly involved in gastric immune and inflammatory responses in the Mongolian gerbils, leading to a more advanced gastric disease.

Concentrations of α-and β-defensins in gastric juice of patients with various gastroduodenal diseases

AIM: To determine the concentration of α-and β-defensins in gastric juice of patients with various gastroduodenal diseases. METHODS: Concentrations of human neutrophil peptides (HNPs) 1-3, the major forms of α-defensins, and human β-defensin (HBD)-1and HBD-2were measured by radioimmunoassay in plasma and gastric juice of 84 subjects, consisting of 54 Helicobacter pylori-infected and 30 uninfected subjects. They included 33 patients with chronic gastritis (CG), 12 with gastric ulcer (GU), 11 with duodenal ulcer (DU), 11 with benign gastric polyp (BGP) and 16 with normal mucosa (N group) on upper endoscopy. Plasma pepsinogen Ⅰ and Ⅱ levels, biomarkers for gastric mucosal inflammation and atrophy, were also measured. RESULTS: Gastric juice HNPs 1-3 levels in patients with CG, GU and BGP were significantly higher than those in patients with DU and N. Gastric juice HBD-2 concentrations in patients with CG and GU were significantly higher than those in the N group, but were significantly lower in DU patients than in GU patients. Gastric juice HBD-1 levels and plasma levels of these peptides were similar in the patient groups. Concentrations of gastric juice HNPs 1-3 and HBD-2 of in H pylori-infected patients were significantly different from those in uninfected subjects. HNPs 1-3 concentrations in gastric juice correlated negatively with plasma pepsinogen I levels and Ⅰ/Ⅱ ratios. HBD-2 levels in gastric juice correlated positively and negatively with plasma pepsinogen Ⅱ concentrations and Ⅰ/Ⅱratios, respectively. CONCLUSION: HNPs 1-3 and HBD-2 levels in gastric juice are diverse among various gastrointestinal diseases, reflecting the inflammatory and atrophic events of the background gastric mucosa affected by H pylori.

IL-11 up-regulates Tie-2 expression during the healing of gastric ulcers in rats

AIM: To investigate Tie-2 expression during the repair of acetic acid-induced gastric ulcers in rats treated with recombinant human IL-11 (rhIL-11) and in untreated control animals.METHODS: Gastric ulcers were induced in male Wistar rats by applying acetic acid to the fundus of the stomach. RhIL-11 (100μg/kg twice daily, subcutaneously) was administered from two days before ulcer induction and continued for five days after the induction. Control rats received bovine serum albumin. Gastric specimens were collected at 3 and 5 days after the induction of ulcer for immunohistochemical observation, Western blotting, and reverse transcription polymerase chain reaction (RT-PCR).RESULTS: Immunohistochemical and Western blot analysis demonstrated that Tie-2 expression was enhanced in the rhIL-11-treated rats compared with the control animals at both intervals.CONCLUSION: These findings suggested that IL-11 could accelerate ulcer healing, in part, by up-regulating Tie-2 expression and promoting angiogenesis.