Cigarette smoke is one of the risk factors for gastric cancer and nicotine has been reported to promote tumor growth. Deregulation of microRNA (miRNA) and cyclooxygenase-2 (COX-2) expressions are hallmarks of many cancers including gastric cancer. Here, we used an miRNA array platform covering a panel of 95 human miRNAs to examine the expression profile in nicotine-treated gastric cancer cells. We found that miR-16 and miR-21 were upregulated upon nicotine stimulation, transfection with anti-miR-16 or anti-miR-21 significantly abrogated cell proliferation. In contrast, ectopic miR-16 or miR-21 expression exhibited a similar stimulatory effect on cell proliferation as nicotine. Nicotine-mediated IkappaBα degradation and nuclear factor-kappa B (NF-κB) translocation dose-dependently. Knockdown of NF-κB by short interfering RNA (siRNA) or specific inhibitor (Bay-11-7085) markedly suppressed nicotine-induced cell proliferation and upregulation of miR-16 and miR-21. Interestingly, NF-κB-binding sites were located in both miR-16 and miR-21 gene transcriptional elements and we showed that nicotine enhanced the binding of NF-κB to the promoters of miR-16 and miR-21. Furthermore, activation of COX-2/prostaglandin E (PGE) signaling in response to nicotine was mediated by the action of prostaglandin E receptors (EP2 and EP4). EP2 or EP4 siRNA or antagonists impaired the nicotine-mediated NF-κB activity, upregulation of miR-16 and miR-21 and cell proliferation. Taken together, these results suggest that miR-16 and miR-21 are directly regulated by the transcription factor NF-κB and yet nicotine-promoted cell proliferation is mediated via EP2/4 receptors. Perhaps this study may shed light on the development of anticancer drugs to improve the chemosensitivity in smokers. © The Author 2010. Published by Oxford University Press. All rights reserved.

Vivian yvonne Shin    Hongchuan Jin    Kaion Ng    Alfred Cheng    Wilson Chong    Wong Christine Y. P.    Wai keung Leung    沈祖堯     Kent man Chu   

Carcinogenesis

2011

Objective: Gastroesophageal reflux disease (GERD) is thought to be less prevalent in China than in Western countries. However, essential population-based endoscopy data are lacking for this country. Material and methods. As part of a wider study, 3600 individuals selected randomly from the Shanghai region were asked to undergo endoscopy. Participants completed a general information questionnaire and a Chinese version of the Reflux Disease Questionnaire. When sufficient numbers were available, associations were assessed using multiple logistic regression or the Wilcoxon rank-sum test. Results. Of 3153 (87.6%) individuals who completed the survey, 1030 (32.7%) agreed to endoscopy and 1029 endoscopies were suitable for analysis. Symptom-defined GERD was more prevalent in the endoscopy group (4.7%) than in the non-endoscopy group (1.7%). Prevalence estimates were 6.4% for reflux esophagitis, 1.8% for endoscopically suspected esophageal metaplasia and 0.7% for hiatus hernia. Reflux esophagitis was more prevalent in patients with symptom-defined GERD than in those without (12.5% [6/48] vs. 6.1% [60/981]), and was significantly associated with reflux symptoms of any frequency or severity (OR = 2.10, 95% CI 1.13-3.89) and with negative Helicobacter pylori infection (OR = 0.44, 95% CI 0.25-0.80). Only 28.8% of participants with reflux esophagitis had heartburn and/or regurgitation symptoms. Epigastric burning was significantly more severe and frequent in participants with reflux esophagitis than in those without (p = 0.05). Conclusions. Reflux esophagitis is less prevalent in China than reported in Western countries. Further work is needed to establish why reflux esophagitis appears less symptomatic in China than in Western countries. © 2011 Informa Healthcare.

Duowu Zou    Jia He    马修强    陈洁    Yanfang Gong    Xiaohua Man    Li Gao    王瑞    Yanfang Zhao    Xiaoyan Yan    Wenbin Liu    Wernersson    Johansson Saga    Dent John    沈祖堯     李兆申   

Scandinavian Journal of Gastroenterology

2011

The paired box 5 (PAX5) is a member of PAX transcription factors family involved in the regulation of embryonic development. However, the role of PAX5 in carcinogenesis is largely unclear. We identified that PAX5 is involved in human cancer by methylation-sensitive representational difference analysis. We examined the biological functions and related molecular mechanisms of PAX5 in hepatocellular carcinoma (HCC). Promoter methylation of PAX5 was evaluated by methylation-specific polymerase chain reaction (PCR) and bisulfite genomic sequencing (BGS). The functions of ectopic PAX5 expression were determined by viability assay, colony formation, and cell cycle analyses, along with in vivo tumorigenicity assays. The PAX5 target signal pathway was identified by promoter luciferase assay, chromosome immunoprecipitation (ChIP), and pathway PCR array. PAX5 is expressed in normal human liver tissue, but silenced or down-regulated in 83% (10/12) of HCC cell lines. The mean expression level of PAX5 was significantly lower in primary HCCs as compared to their adjacent normal tissues (P < 0.0001). The promoter methylation contributes to the inactivation of PAX5. Restoring PAX5 expression in silenced HCC cell lines suppressed cell proliferation, induced apoptosis in vitro, and inhibited tumor growth in nude mice (P < 0.0001). The pathway luciferase reporter assay indicated that PAX5 activated p53 and p21 signaling. ChIP analysis demonstrated that PAX5 directly bound to the p53 promoter. The antitumorigenic function of PAX5 was at least up-regulated by p53 and its downstream targets including tumor necrosis factor, Fas ligand, leucine-rich repeats, and death domain-containing, poly(rC) binding protein 4, p21, and growth arrest and DNA-damage-inducible alpha. Conclusion: PAX5 is frequently inactivated by promoter methylation in HCC. PAX5 appears to be a functional tumor suppressor involved in liver carcinogenesis through direct regulation of the p53 signaling pathway. © 2010 American Association for the Study of Liver Diseases.

Liu Wei-Li    Xiaoxing Li    Eagle Chu    Minnieyy Go    Xu Lixia    Zhao Guijun    Li Li-Li    戴宁    Si Jian-Min    Qian Tao    沈祖堯     Jun Yu   

Hepatology

2011

Introduction: Efficacy of a continuous high-dose intravenous infusion of esomeprazole, followed by an oral regimen after successful endoscopic therapy for peptic ulcer bleeding (PUB) was established in the PUB study (ClinicalTrials. gov identifier: NCT00251979). Mortality rates and detailed safety and tolerability results from this study are reported here. Methods: This was a double-blind, randomized study in patients ≥18 years with overt signs of upper gastrointestinal bleeding, following endoscopic diagnosis of a single gastric or duodenal ulcer (≥5 mm) with stigmata indicating current/ recent bleeding (Forrest class Ia, Ib, IIa, or IIb). Postendoscopic hemostasis, patients received intravenous esomeprazole (80 mg/30 minutes, then 8 mg/hour for 71.5 hours) or placebo. Postinfusion, all patients received open-label oral esomeprazole 40 mg once daily for 27 days. Mortality rates were analyzed using Fisher's exact test; other safety variables were analyzed descriptively. Results: A total of 767 patients were randomized; 764 comprised the safety analysis set (375 patients received esomeprazole, 389 placebo). Baseline characteristics were similar across the two treatment groups. Three deaths from the esomeprazole treatment group and eight from the placebo group occurred during the trial (0.8% versus 2.1%; P=0.22). From these 11 all-cause deaths, one (esomeprazole group; rebleeding from duodenal ulcer) occurred during the 72-hour intravenous treatment phase. Adverse event (AE) frequency was similar for the two groups over the intravenous treatment phase (esomeprazole, 39.2%; placebo, 41.9%), with gastrointestinal disorders being most commonly reported (12.3% and 19.8%, respectively). Serious AEs were mostly related to bleeding events. Infusion-site reactions (mild, transient) were reported in 4.3% of esomeprazole-treated patients versus 0.5% of placebo patients. These did not lead to treatment discontinuation. Conclusion: Esomeprazole, given as a continuous high-dose intravenous infusion followed by an oral regimen after successful endoscopic therapy for PUB, was well tolerated, with no apparent safety concerns from either the high-dose intravenous treatment or oral phases. © 2010 Springer Healthcare.

Ernst johan Kuipers    沈祖堯     Alan Barkun    Joachim Mossner    Jensen    Stuart    James Lau    Ahlbom    Tore Lind    Kilhamn Jan   

Advances in Therapy

2011

Background and study aims: Endoscopic therapy of upper gastrointestinal bleeding remains challenging with conventional endoscopic devices. Use of Hemospray, where a nanopowder with clotting abilities is sprayed onto the bleeding site, had been highly effective for management of arterial bleeding in a heparizined animal model. The safety and effectiveness of Hemospray for hemostasis of active peptic ulcer bleeding in humans was evaluated. Patients and methods: In a prospective, single-arm, pilot clinical study, consecutive adults with confirmed peptic ulcer bleeding (Forrest score Ia or Ib), who had all given informed consent to participation, underwent upper gastrointestinal endoscopy and application of Hemospray within 24 hours of hospital admission once hemodynamically stable. Up to two applications of Hemospray, not exceeding a total of 150 g were allowed. Bleeding recurrence was monitored post procedurally, by second-look endoscopy (72 hours post treatment), and by phone at 30 days. Rate of hemostasis, recurrent bleeding, mortality, need for surgical intervention, and treatment-related complications were assessed. Results: 20 patients were recruited (18 men, 2 women; mean age 60.2 years). Acute hemostasis was achieved in 95 % (19 / 20) of patients; 1 patient had a pseudoaneurysm requiring arterial embolization. Bleeding recurred in 2 patients within 72 hours (shown by hemoglobin drop); neither had active bleeding identified at the 72-hour endoscopy. No mortality, major adverse events, or treatment- or procedure-related serious adverse events were reported during 30-day follow-up. Conclusion: These pilot results indicate that Hemospray is safe in humans. Hemospray was effective in achieving acute hemostasis in active peptic ulcer bleeding. © Georg Thieme Verlag KG Stuttgart - New York.

沈祖堯     Luo    胡志    Jessica Ching    Francis Chan    James Lau    MacK    Ducharme Richard W.    Okolo III Patrick I.    Marcia irene Canto    Anthony Kalloo    Giday   

Endoscopy

2011

Aims: Post-infectious irritable bowel syndrome (PI-IBS) is a subset of IBS which occurs after an episode of acute gastrointestinal infections. The mechanisms of PI-IBS are not fully understood. Currently, numerous animal models have been used in the study of PI-IBS. This article reviews the strengths and weaknesses of these models. Methods: All relevant articles were identified by searching in Ovid SP from 1962, the year the term PI-IBS was coined, up to December 31, 2009. The types of model were categorized as either post-infectious or post-inflammatory, and the characteristics of each kind of model were listed. Results: Based on our literature search, 268 articles were identified. Of those articles, 50 were included in this review. The existing PI-IBS models include infection with bacteria (e.g., Campylobacter jejuni, Salmonella enterica, and Campylobacter rodentium), and infection with parasites (e.g., Trichinella spiralis, Nippostrongylus brasiliensis, and Cryptosporidium parvum). The post-inflammatory IBS models are commonly induced with chemical agents, such as acetic acid, deoxycholic acid, dextran sulfate sodium, mustard oil, zymosan, and trinitrobenzene sulfonic acid (TNBS). TNBS is the most commonly used agent for post-inflammatory IBS models, but the experimental protocol varies. These models have one or more aspects similar to IBS patients. Conclusions: Different methods have been used for the development of post-infectious or post-inflammatory IBS models. Each model has its weaknesses and strengths. More studies are needed to establish post-infection IBS models using more common pathogens. A standard protocol in developing TNBS-induced post-inflammatory IBS model is needed. © 2010 Springer.

Hongyan Qin    胡志    Tong Xu-Dong    沈祖堯     徐宏喜    Zhaoxiang Bian   

Journal of Gastroenterology

2011

Background and Aim: Helicobacter pylori infection remains common in East Asia, though its prevalence is decreasing in Western countries. H. pylori-related atrophic gastritis (AG) may reduce the likelihood of gastroesophageal reflux disease (GERD). We investigated the prevalence of H. pylori infection and AG and their association with endoscopic findings and symptom-defined GERD in Shanghai. Methods: A representative random sample of 3600 Shanghai residents aged 18-80years was invited to complete a general information questionnaire and a Chinese version of the Reflux Disease Questionnaire, to provide blood samples for H. pylori serology and pepsinogen (PG) I/II assay (to detect AG, defined as PGI<70μg/L and/or PGI/PGII<7), and to undergo endoscopy. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by multivariate logistic regression. Results: A total of 1022 Shanghai residents underwent endoscopy and were valid for inclusion in the study. Of these, 71.7% tested positive for H. pylori, 63.8% had AG and 30.5% had moderate/severe AG (PGI<50μg/L and/or PGI/PGII<5). Helicobacter pylori infection was equally common in all age groups. Severity of AG increased with age in women. Reflux esophagitis was inversely associated with AG (OR, 0.23 [CI, 0.09-0.55] for moderate/severe AG compared with no H. pylori or gastritis). However, symptom-defined GERD showed no clear association with AG. Conclusions: Helicobacter pylori infection and AG are very common in Shanghai, and the infection is acquired early in life. Atrophic gastritis is inversely associated with reflux esophagitis but is not significantly associated with symptom-defined GERD. © 2011 Journal of Gastroenterology and Hepatology Foundation and Blackwell Publishing Asia Pty Ltd.

Duowu Zou    Jia He    马修强    Wenbin Liu    陈洁    Xingang Shi    Ye Ping    Yanfang Gong    Yanfang Zhao    王瑞    Xiaoyan Yan    Xiaohua Man    Li Gao    Dent John    沈祖堯     Wernersson    Johansson Saga    李兆申   

Journal of Gastroenterology and Hepatology (Australia)

2011

Prostaglandin E (EP) receptor is positively related with COX-2, which is involved in cancer biology. A mechanistic study on how 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) promotes gastric carcinogenesis is lacking. Recently, we found that nicotine promoted tumor growth through upregulation of the COX-2/prostaglandin E pathway. This extended our study on the involvement of EP receptors in gastric carcinogenesis. Both in vitro and in vivo studies showed that NNK promoted cancer cell growth with concomitant EP2 and EP4 upregulation. We found that NNK stimulated vascular endothelial growth factor (VEGF) and angiogenesis, but suppressed apoptosis by increasing Bcl2 and decreasing caspase-3 expressions. Both EP2 and EP4 siRNA significantly impaired these tumorigenic actions of NNK in xenograft tumor. Cell cycle analysis showed that NNK increased S phase entry with increased cyclin D1 and the associated cyclin-dependent kinase 4/6, and downregulation of p21 and p27. The p38 phosphorylation was EP2/4-dependent, and SB203580 (p38 inhibitor) suppressed NNK-induced prostaglandin E , VEGF, and cell proliferation. Antagonists of EP2 or EP4 abolished the elevated VEGF and VEGF receptor-2. These data strongly indicate that EP2/4 are important for NNK-promoted gastric carcinogenesis, thus providing a framework for future evaluation of EP antagonist(s) as anticancer drugs for smokers. © 2011 Japanese Cancer Association.

Vivian yvonne Shin    Hongchuan Jin    Kaion Ng    Chihin Cho    Leung Wai K.    沈祖堯     Kent man Chu   

Cancer Science

2011

Background: The biological pathways and functional properties by which misexpressed microRNAs (miRNAs) contribute to liver carcinogenesis have been intensively investigated. However, little is known about the upstream mechanisms that deregulate miRNA expressions in this process. In hepatocellular carcinoma (HCC), hepatitis B virus (HBV) X protein (HBx), a transcriptional trans-activator, is frequently expressed in truncated form without carboxyl-terminus but its role in miRNA expression and HCC development is unclear. Methods: Human non-tumorigenic hepatocytes were infected with lentivirus-expressing full-length and carboxyl-terminal truncated HBx (Ct-HBx) for cell growth assay and miRNA profiling. Chromatin immunoprecipitation microarray was performed to identify the miRNA promoters directly associated with HBx. Direct transcriptional control was verified by luciferase reporter assay. The differential miRNA expressions were further validated in a cohort of HBV-associated HCC tissues using real-time PCR. Results: Hepatocytes expressing Ct-HBx grew significantly faster than the full-length HBx counterparts. Ct-HBx decreased while full-length HBx increased the expression of a set of miRNAs with growth-suppressive functions. Interestingly, Ct-HBx bound to and inhibited the transcriptional activity of some of these miRNA promoters. Notably, some of the examined repressed-miRNAs (miR-26a, -29c, -146a and -190) were also significantly down-regulated in a subset of HCC tissues with carboxyl-terminal HBx truncation compared to their matching non-tumor tissues, highlighting the clinical relevance of our data. Conclusion: Our results suggest that Ct-HBx directly regulates miRNA transcription and in turn promotes hepatocellular proliferation, thus revealing a viral contribution of miRNA deregulation during hepatocarcinogenesis. © 2011 Yip et al.

Yip Wing-Kit    Alfred Cheng    Zhu Ranxu    Raymond wai ming Lung    Tsang Daisy Pui-Fong    Lau Suki Shuk-Kei    Yangchao Chen    Sung Jonathan Gabriel    Paul Lai    Kaion Ng    于俊    王昭春    Kafai To    Vincent Wong    沈祖堯     Henry lik yuen Chan   

PLoS ONE

2011

Upper gastrointestinal bleeding (UGIB), especially peptic ulcer bleeding, remains one of the most important cause of hospitalisation and mortality world wide. In Asia, with a high prevalence of Helicobacter pylori infection, a potential difference in drug metabolism, and a difference in clinical management of UGIB due to variable socioeconomic environments, it is considered necessary to re-examine the International Consensus of Non-variceal Upper Gastrointestinal Bleeding with emphasis on data generated from the region. The working group, which comprised experts from 12 countries from Asia, recommended the use of the Blatchford score for selection of patients who require endoscopic intervention and which would allow early discharge of patients at low risk. Patients' comorbid conditions should be included in risk assessment. A pre-endoscopy proton pump inhibitor (PPI) is recommended as a stop-gap treatment when endoscopy within 24 h is not available. An adherent clot on a peptic ulcer should be treated with endoscopy combined with a PPI if the clot cannot be removed. Routine repeated endoscopy is not recommended. High-dose intravenous and oral PPIs are recommended but low-dose intravenous PPIs should be avoided. COX-2 selective non-steroidal anti-inflammatory drugs combined with a PPI are recommended for patients with very high risk of UGIB. Aspirin should be resumed soon after stabilisation and clopidogrel alone is no safer than aspirin plus a PPI. When dual antiplatelet agents are used, prophylactic use of a PPI reduces the risk of adverse gastrointestinal events.

沈祖堯     Francis Chan    陈旻湖    Jessica Ching    Khek yu Ho    Kachintorn Udom    Nayoung Kim    James Lau    Menon    Abdul aziz Rani    Nageshwar duvvuru Reddy    José Sollano    Sugano Kentaro    Kelvin kf Tsoi    Chunying Wu    Yeomans Neville    Vakil Namish    Khean lee Goh   

Gut

2011