Sa1846 Global and Gene Specific DNA Methylation Changes in Barrett's Epithelium and Adjacent Normal Mucosa

Abstract Background and aim Recent studies have proposed that commensal bacteria might be involved in the development and progression of gastrointestinal disorders such as colorectal cancer (CRC). Therefore, in this study, the relative abundance of Fusobacterium nucleatum, Bacteroides fragilis, Streptococcus bovis/gallolyticus, and Enteropathogenic Escherichia coli (EPEC) in CRC tissues, and their association with clinicopathologic characteristics of CRC was investigated in Iranian patients. Moreover, the role of these bacteria in the CRC-associated mutations including PIK3CA, KRAS, and BRAF was studied. Method To these ends, the noted bacteria were quantified in paired tumors and normal tissue specimens of 30 CRC patients, by TaqMan quantitative Real-Time Polymerase Chain Reaction (qPCR). Next, possible correlations between clinicopathologic factors and mutations in PIK3CA, KRAS, and BRAF genes were analyzed. Results In studied samples, B. fragilis was the most abundant bacteria that was detected in 66 and 60% of paired tumor and normal samples, respectively. Furthermore, 15% of the B. fragilis-positive patients were infected with Enterotoxigenic B. fragilis (ETBF) in both adenocarcinoma and matched adjacent normal samples. F. nucleatum was also identified in 23% of tumors and 13% of adjacent normal tissue samples. Moreover, the relative abundance of these bacteria determined by 2-ΔCT was significantly higher in CRC samples than in adjacent normal mucosa (p < 0.05). On the other hand, our findings indicated that S. gallolyticus and EPEC, compared to adjacent normal mucosa, were not prevalent in CRC tissues. Finally, our results revealed a correlation between F. nucleatum-positive patients and the KRAS mutation (p = 0.02), while analyses did not show any association between bacteria and mutation in PIK3CA and BRAF genes. Conclusion The present study is the first report on the analysis of different bacteria in CRC tissue samples of Iranian patients. Our findings revealed that F. nucleatum and B. fragilis might be linked to CRC. However, any link between gut microbiome dysbiosis and CRC remains unknown.

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Genome-wide analysis identifies critical DNA methylations within NTRKs genes in colorectal cancer

Journal of Translational Medicine ◽

10.1186/s12967-021-02740-6 ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Zijian Chen ◽

Zenghong Huang ◽

Yanxin Luo ◽

Qi Zou ◽

Liangliang Bai ◽

...

Keyword(s):

Colorectal Cancer ◽

Dna Methylation ◽

Promoter Methylation ◽

Expression Profiles ◽

Methylation Status ◽

Gene Promoter ◽

Normal Mucosa ◽

Suppressor Gene ◽

Survival Outcome ◽

Prognostic Models

Abstract Background Neurotrophic tropomyosin receptor kinases (NTRKs) are a gene family function as oncogene or tumor suppressor gene in distinct cancers. We aimed to investigate the methylation and expression profiles and prognostic value of NTRKs gene in colorectal cancer (CRC). Methods An analysis of DNA methylation and expression profiles in CRC patients was performed to explore the critical methylations within NTRKs genes. The methylation marker was validated in a retrospectively collected cohort of 229 CRC patients and tested in other tumor types from TCGA. DNA methylation status was determined by quantitative methylation-specific PCR (QMSP). Results The profiles in six CRC cohorts showed that NTRKs gene promoter was more frequently methylated in CRC compared to normal mucosa, which was associated with suppressed gene expression. We identified a specific methylated region within NTRK3 promoter targeted by cg27034819 and cg11525479 that best predicted survival outcome in CRC. NTRK3 promoter methylation showed independently predictive value for survival outcome in the validation cohort (P = 0.004, HR 2.688, 95% CI [1.355, 5.333]). Based on this, a nomogram predicting survival outcome was developed with a C-index of 0.705. Furthermore, the addition of NTRK3 promoter methylation improved the performance of currently-used prognostic model (AIC: 516.49 vs 513.91; LR: 39.06 vs 43.64, P = 0.032). Finally, NTRK3 promoter methylation also predicted survival in other tumors, including pancreatic cancer, glioblastoma and stomach adenocarcinoma. Conclusions This study highlights the essential value of NTRK3 methylation in prognostic evaluation and the potential to improve current prognostic models in CRC and other tumors.

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Audit of a Barrett's epithelium surveillance database

European Journal of Gastroenterology & Hepatology ◽

10.1097/00042737-200402000-00008 ◽

2004 ◽

Vol 16 (2) ◽

pp. 171-175 ◽

Cited By ~ 26

Author(s):

K K Basu ◽

B Pick ◽

J S de Caestecker

Keyword(s):

Barrett’S Epithelium ◽

Barrett's Epithelium ◽

Surveillance Database

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Banding Without Resection (Endoscopic Mucosal Ligation) as a Novel Approach for the Ablation of Short-Segment Barrett's Epithelium: Results of a Pilot Study

The American Journal of Gastroenterology ◽

10.1111/j.1572-0241.2007.01256.x ◽

2007 ◽

Vol 102 (8) ◽

pp. 1640-1645 ◽

Cited By ~ 8

Author(s):

Edgardo Diaz-Cervantes ◽

Antonio De-la-Torre-Bravo ◽

Stuart Jon Spechler ◽

Ernesto Torres-Durazo ◽

Sergio Sobrino-Cossio ◽

...

Keyword(s):

Pilot Study ◽

Short Segment ◽

Barrett’S Epithelium ◽

Novel Approach ◽

Barrett's Epithelium

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Canadian Consensus Conference on the Management of Gastroesophageal Reflux Disease in Adults – Update 2004

Canadian Journal of Gastroenterology ◽

10.1155/2005/836030 ◽

2005 ◽

Vol 19 (1) ◽

pp. 15-35 ◽

Cited By ~ 136

Author(s):

David Armstrong ◽

John K Marshall ◽

Naoki Chiba ◽

Robert Enns ◽

Carlo A Fallone ◽

...

Keyword(s):

Quality Of Life ◽

Reflux Disease ◽

Symptom Relief ◽

Management Strategies ◽

Consensus Conference ◽

Optimal Management ◽

Barrett’S Epithelium ◽

Barrett's Epithelium ◽

Gerd Symptoms

BACKGROUND: Gastroesophageal reflux disease (GERD) is the most prevalent acid-related disorder in Canada and is associated with significant impairment of health-related quality of life. Since the last Canadian Consensus Conference in 1996, GERD management has evolved substantially.OBJECTIVE: To develop up-to-date evidence-based recommendations relevant to the needs of Canadian health care providers for the management of the esophageal manifestations of GERD.CONSENSUS PROCESS: A multidisciplinary group of 23 voting participants developed recommendation statements using a Delphi approach; after presentation of relevant data at the meeting, the quality of the evidence, strength of recommendation and level of consensus were graded by participants according to accepted principles.OUTCOMES: GERD applies to individuals who reflux gastric contents into the esophagus causing symptoms sufficient to reduce quality of life, injury or both; endoscopy-negative reflux disease applies to individuals who have GERD and a normal endoscopy. Uninvestigated heartburn-dominant dyspepsia -- characterised by heartburn or acid regurgitation - includes erosive esophagitis or endoscopy-negative reflux disease, and may be treated empirically as GERD without further investigation provided there are no alarm features. Lifestyle modifications are ineffective for frequent or severe GERD symptoms; over-the-counter antacids or histamine H2-receptor antagonists are effective for some patients with mild or infrequent GERD symptoms. Proton pump inhibitors are more effective for healing and symptom relief than histamine H2-receptor antagonists; their efficacy is proportional to their ability to reduce intragastric acidity. Response to initial therapy - a once-daily proton pump inhibitor unless symptoms are mild and infrequent (fewer than three times per week) - should be assessed at four to eight weeks. Maintenance medical therapy should be at the lowest dose and frequency necessary to maintain symptom relief; antireflux surgery is an alternative for a small proportion of selected patients. Routine testing for Helicobacter pylori infection is unnecessary before starting GERD therapy. GERD is associated with Barrett's epithelium and esophageal adenocarcinoma but the risk of malignancy is very low. Endoscopic screening for Barrett's epithelium may be considered in adults with GERD symptoms for more than 10 years; Barrett's epithelium and low-grade dysplasia generally warrant surveillance; endoscopic or surgical management should be considered for confirmed high-grade dysplasia or malignancy.CONCLUSION: Prospective studies are needed to investigate clinically relevant risk factors for the development of GERD and its complications; GERD progression, on and off therapy; optimal management strategies for typical GERD symptoms in primary care patients; and optimal management strategies for atypical GERD symptoms, Barrett's epithelium and esophageal adenocarcinoma.

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