Barrett's Carcinogenesis Research Articles

Quantitative analysis of p16 methylation in Barrett's carcinogenesis

p16 hypermethylation in Barrett's carcinogenesis has been evaluated in studies which did not take into account sample heterogeneity and yielded qualitative (methylated/unmethylated) instead of accurate quantitative (percentage of CpG methylation) data. We aimed to measure the degree of p16 methylation in pure samples representing all the steps of Barrett's tumorogenesis and to evaluate the influence of sample heterogeneity in methylation analysis. Methods: 77 paraffin-embedded human esophageal samples were analyzed. Histological grading was established by two pathologists in: negative for dysplasia, indefinite for dysplasia, low-grade dysplasia, high-grade dysplasia and adenocarcinoma. Areas of interest were selected by laser-capture microdissection. p16 methylation was quantified by pyrosequencing. An adjacent section of the whole sample was also analyzed to compare methylation data. Results: After microdissection, we obtained 15 samples of squamous epithelium, 36 non-dysplastic Barrett's esophagus, 3 indefinite for dysplasia, 24 low-grade dysplasia, 4 high-grade dysplasia and 12 adenocarcinoma. Squamous epithelium showed the lowest methylation rates: 6% (IQR 5–11) vs. 11%(7–39.50) in negative/indefinite for dysplasia, p<0.01; 10.60%(6–24) in low-grade dysplasia, p<0.05; and 44.50%(9–66.75) in high-grade dysplasia/adenocarcinoma, p<0.01. This latter group also exhibited higher methylation rates than Barrett's epithelium with and without low-grade dysplasia (p<0.05). p16 methylation rates of microdissected and non-microdissected samples did not correlate unless the considered histological alteration comprised >71% of the sample. Conclusions: p16 methylation is an early event in Barrett's carcinogenesis which increases with the severity of histological alteration. p16 methylation rates are profoundly influenced by sample heterogeneity, so selection of samples is crucial in order to detect differences.

Relationship between Barrett's esophagus and colonic diseases: a role for colonoscopy in Barrett's surveillance.

Given that risk factors for Barrett's carcinogenesis are predictive, appropriate management and surveillance of Barrett's esophagus (BE) may be provided. The presence of colorectal neoplasms (CRNs) is a possible predictor of the development of BE and the progression to esophageal adenocarcinoma (EAC). We evaluated the relationship between BE or EAC and colonic diseases, including neoplasms and diverticulosis. Patients (N = 5606) who underwent both colonoscopy and esophagogastroduodenoscopy between January 2016 and December 2017 at three institutions were enrolled. The relationships between the presence of colonic diseases and BE or EAC and other clinical or endoscopic predictors of the presence of BE were investigated retrospectively. The prevalence of BE ≥ 1cm and ≥ 3cm in length was 13.0% and 0.52%, respectively. BE was closely related with the presence of colorectal adenoma (48.4% vs. 37.2% in non-BE; P < 0.001), adenocarcinoma (16.6% vs. 8.4%, P < 0.001) and colonic diverticulosis (CD) (34.1% vs. 29.3%, P < 0.001). In patients with long-segment BE, CRNs (79.3%, P < 0.001) and CD (48.2%, P = 0.038) were more common. EAC patients also had a statistically significantly higher incidence of CRNs than non-BE patients (87.5% vs. 45.6%, P = 0.027). Diverticulosis at the distal colon correlated significantly with EAC and BE (50.0%, P = 0.010 and 15.4%, P = 0.024, vs. 12.0% in non-BE). Multivariate analysis showed that CRNs (t = 8.55, P < 0.001), reflux esophagitis (t = 5.26, P < 0.001) and hiatal hernia (t = 11.68, P < 0.001) were predictors of BE. The presence of CRNs was strongly associated with BE and EAC. Therefore, colonoscopy may be useful for establishing a strategy for the surveillance of BE.

Preclinical models for the study of Barrett's carcinogenesis.

Barrett's esophagus (BE) is clinically significant, as it is the only known precursor lesion for esophageal adenocarcinoma. To develop improved therapies for the treatment of BE, a greater understanding of the disease process at the molecular genetic level is needed. However, achieving a greater understanding will require improved preclinical models so that the disease process can be more closely studied and novel therapies can be tested. Our concise review highlights progress in the development of preclinical models for the study of BE and identifies the most suitable model in which to test novel therapies.

High yield reproducible rat model recapitulating human Barrett's carcinogenesis.

AIMTo efficiently replicate the biology and pathogenesis of human esophageal adenocarcinoma (EAC) using the modified Levrat model of end-to-side esophagojejunostomy.METHODSEnd-to-side esophagojejunostomy was performed on rats to induce gastroduodenoesophageal reflux to develop EAC. Animals were randomly selected and serially euthanized at 10 (n = 6), 17 (n = 8), 24 (n = 9), 31 (n = 6), 38 (n = 6), and 40 (n = 6) wk postoperatively. The esophagi were harvested for downstream histopathology and gene expression. Histological evaluation was completed to determine respective rates of carcinogenic development. Quantitative reverse transcription-polymerase chain reaction was performed to determine gene expression levels of MUC2, CK19, and CK20, and results were compared to determine significant differences throughout disease progression stages.RESULTSThe overall study mortality was 15%. Causes of mortality included anastomotic leak, gastrointestinal hemorrhage, stomach ulcer perforation, respiratory infection secondary to aspiration, and obstruction due to tumor or late anastomotic stricture. 10 wk following surgery, 100% of animals presented with esophagitis. Barrett’s esophagus (BE) was first observed at 10 wk, and was present in 100% of animals by 17 wk. Dysplasia was confirmed in 87.5% of animals at 17 wk, and increased to 100% by 31 wk. EAC was first observed in 44.4% of animals at 24 wk and increased to 100% by 40 wk. In addition, two animals at 38-40 wk post-surgery had confirmed macro-metastases in the lung/liver and small intestine, respectively. MUC2 gene expression was progressively down-regulated from BE to dysplasia to EAC. Both CK19 and CK20 gene expression significantly increased in a stepwise manner from esophagitis to EAC.CONCLUSIONEsophagojejunostomy was successfully replicated in rats with low mortality and a high tumor burden, which may facilitate broader adoption to study EAC development, progression, and therapeutics.

Quantitative Shotgun Proteomics Unveils Candidate Novel Esophageal Adenocarcinoma (EAC)-specific Proteins

Esophageal cancer is the eighth most common cancer worldwide and the majority of patients have systemic disease at presentation. Esophageal adenocarcinoma (OAC), the predominant subtype in western countries, is largely resistant to current chemotherapy regimens. Selective markers are needed to enhance clinical staging and to allow targeted therapies yet there are minimal proteomic data on this cancer type. After histological review, lysates from OAC and matched normal esophageal and gastric samples from seven patients were subjected to LC MS/MS after tandem mass tag labeling and OFFGEL fractionation. Patient matched samples of OAC, normal esophagus, normal stomach, lymph node metastases and uninvolved lymph nodes were used from an additional 115 patients for verification of expression by immunohistochemistry (IHC).Over six thousand proteins were identified and quantified across samples. Quantitative reproducibility was excellent between technical replicates and a moderate correlation was seen across samples with the same histology. The quantitative accuracy was verified across the dynamic range for seven proteins by immunohistochemistry (IHC) on the originating tissues. Multiple novel tumor-specific candidates are proposed and EPCAM was verified by IHC.This shotgun proteomic study of OAC used a comparative quantitative approach to reveal proteins highly expressed in specific tissue types. Novel tumor-specific proteins are proposed and EPCAM was demonstrated to be specifically overexpressed in primary tumors and lymph node metastases compared with surrounding normal tissues. This candidate and others proposed in this study could be developed as tumor-specific targets for novel clinical staging and therapeutic approaches.

Mo2048 - Effect of Benzo[A]Pyrene Along with Acid and Bile is Highly Carcinogenic as Shown in Thein-Vitro Barrett's Esophagus Carcinogenesis (BEC) Model

Mo2048 - Effect of Benzo[A]Pyrene Along with Acid and Bile is Highly Carcinogenic as Shown in Thein-Vitro Barrett's Esophagus Carcinogenesis (BEC) Model

Squamous cell carcinoma antigen (SCCA) is up-regulated during Barrett's carcinogenesis and predicts esophageal adenocarcinoma resistance to neoadjuvant chemotherapy.

Squamous Cell Carcinoma Antigen (SCCA) is consistently overexpressed in many different solid tumors, and has been associated with both tumor aggressiveness and chemoresistance. No data, however, is currently available on SCCA expression during esophageal Barrett's carcinogenesis, nor on SCCA expression's role on esophageal adenocarcinoma chemoresistance. The SCCA immunohistochemical expression was assessed in a series of 100 biopsy samples covering the whole histological spectrum of Barrett's oncogenesis. Squamous native mucosa was characterized by a moderate to strong cytoplasmic and nuclear SCCA expression in suprabasal, medium, and superficial layers. On the other hand, almost half of the considered lesions did not express SCCA; the other half featured weak to moderate SCCA expression. The relationship between SCCA protein expression and tumor response to neoadjuvant chemotherapy was assessed in 90 esophageal adenocarcinoma specimens (40 biopsy and 50 surgery specimens), stratified according to Mandard tumor regression grade. As observed in other settings, the presence of SCCA expression clustered in the group of tumors characterized by a lower responsiveness to neoadjuvant treatments. The present results suggest an involvement of SCCA in a subset of Barrett-related tumors, and prompt to consider the SCCA-protein expression as response-predictive marker of neoadjuvant therapy in esophageal adenocarcinomas.

A non-endoscopic device to sample the oesophageal microbiota: a case-control study

SummaryBackgroundThe strongest risk factor for oesophageal adenocarcinoma is reflux disease, and the rising incidence of this coincides with the eradication of Helicobacter pylori, both of which might alter the oesophageal microbiota. We aimed to profile the microbiota at different stages of Barrett's carcinogenesis and investigate the Cytosponge as a minimally invasive tool for sampling the oesophageal microbiota.MethodsIn this case-control study, 16S rRNA gene amplicon sequencing was done on 210 oesophageal samples from 86 patients representing the Barrett's oesophagus progression sequence (normal squamous controls [n=20], non-dysplastic [n=24] and dysplastic Barrett's oesophagus [n=23], and oesophageal adenocarcinoma [n=19]), relevant negative controls, and replicates on the Illumina MiSeq platform. Samples were taken from patients enrolled in the BEST2 study at five UK hospitals and the OCCAMS study at six UK hospitals. We compared fresh frozen tissue, fresh frozen endoscopic brushings, and the Cytosponge device for microbial DNA yield (qPCR), diversity, and community composition.FindingsThere was decreased microbial diversity in oesophageal adenocarcinoma tissue compared with tissue from healthy control patients as measured by the observed operational taxonomic unit (OTU) richness (p=0·0012), Chao estimated total richness (p=0·0004), and Shannon diversity index (p=0·0075). Lactobacillus fermentum was enriched in oesophageal adenocarcinoma (p=0·028), and lactic acid bacteria dominated the microenvironment in seven (47%) of 15 cases of oesophageal adenocarcinoma. Comparison of oesophageal sampling methods showed that the Cytosponge yielded more than ten-times higher quantities of microbial DNA than did endoscopic brushes or biopsies using quantitative PCR (p<0·0001). The Cytosponge samples contained the majority of taxa detected in biopsy and brush samples, but were enriched for genera from the oral cavity and stomach, including Fusobacterium, Megasphaera, Campylobacter, Capnocytophaga, and Dialister. The Cytosponge detected decreased microbial diversity in patients with high-grade dysplasia in comparison to control patients, as measured by the observed OTU richness (p=0·0147), Chao estimated total richness (p=0·023), and Shannon diversity index (p=0·0085).InterpretationAlterations in microbial communities occur in the lower oesophagus in Barrett's carcinogenesis, which can be detected at the pre-invasive stage of high-grade dysplasia with the novel Cytosponge device. Our findings are potentially applicable to early disease detection, and future test development should focus on longitudinal sampling of the microbiota to monitor for changes in microbial diversity in a larger cohort of patients.FundingCancer Research UK, National Institute for Health Research, Medical Research Council, Wellcome Trust, The Scottish Government (RESAS).

Abstract 1258: Therapeutic potential of the cyclin- dependent kinase inhibitor on c-Myc overexpressing esophageal adenocarcinoma

Abstract Introduction: Esophageal adenocarcinoma (EAC) is now the fastest growing cancer in the western world and most EAC patients present with widespread metastatic disease, where current treatment is largely ineffective. Therefore, new therapeutic approaches are urgently needed. The transcription factor proto-oncogene c-Myc is a potent activator of tumorigenesis. Tumors with elevated c-Myc expression often exhibit highly aggressive phenotype. c-Myc amplification has been shown to be frequent in esophageal adenocarcinoma and has been implicated in Barrett's carcinogenesis. Emerging data suggests that synthetic lethal interactions between c-Myc pathway activation and small molecules inhibition involved in cell cycle signaling can be therapeutically exploited to preferentially kill tumor cells. In this study, we therefore investigated whether exploiting a synthetic-lethal approach dependent on elevated c-Myc signaling is effective in treating esophageal cancer with a cyclin-dependent kinase (CDK) inhibitor flavopiridol. Methods: Western blot analysis was done to see the expression of c-Myc and apoptotic signaling pathways in a panel of nine esophageal cancer cell lines. c-Myc overexpression and knockdown were performed using both genetic and novel chemical approaches. Cell viability assays were performed in 96-well plates using the colorimetric WST-1 reagent. Esophageal cancer tumors growth was measured in xenograft and a novel peritoneal disseminated metastatic survival model of immunodeficient mice. Results: Western blot analysis revealed frequent overexpression of c-Myc in EAC cell lines. In this panel of esophageal cancer cell lines tested more than 70% of EAC cell lines showed overexpression of c-Myc. When we tested these cell lines for their ability to form xenograft tumor and peritoneal dissemination, c-Myc overexpression correlated with accelerated EAC tumor growth in xenograft and peritoneal disseminated metastatic survival model of NOD/SCID mice. The xenograft tumor growth rate and formation rate of peritoneal cancer after injection of 5 million cells were highest in OE19 EAC cell line which showed the highest c-Myc expression. In addition, median animal survival with peritoneal dissemination was lowest for OE19 (55 days) whereas OACM5.1 C EAC cell line which had the lowest c-Myc expression didn't form any peritoneal tumor. EAC cell lines with elevated c-Myc expression are preferentially more sensitive to induction of apoptosis by CDK inhibitor flavopiridol compared to EAC cell lines with lower c-Myc expression. When we tested the role of c-Myc expression by upregulation/downregulation in this apoptotic effect we found that this effect is very much dependent on c-Myc expression. Conclusion: These results indicate that CDK inhibitor alone or in combination with other cytotoxic or targeted agents can be a potential therapy for c-Myc overexpressing EAC. Citation Format: Sazzad Hassan, Niranjan Awasthi, Margaret A. Schwarz, Roderich E. Schwarz, Urs V. Holzen. Therapeutic potential of the cyclin- dependent kinase inhibitor on c-Myc overexpressing esophageal adenocarcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1258.

Role of nitric oxide in the pathogenesis of Barrett’s-associated carcinogenesis

Barrett's esophagus (BE), a premalignant condition to Barrett's adenocarcinoma (BAC), is closely associated with chronic inflammation due to gastro-esophageal reflux. Caudal type homeobox 2 (CDX2), a representative marker of BE, is increased during the metaplastic and neoplastic transformation of BE. Nitric oxide (NO) has been proposed to be a crucial mediator of Barrett's carcinogenesis. We previously demonstrated that CDX2 might be induced directly under stimulation of large amounts of NO generated around the gastro-esophageal junction (GEJ) by activating epithelial growth factor receptor in a ligand-independent manner. Thus, we reviewed recent developments on the role of NO in Barrett's carcinogenesis. Notably, recent studies have reported that microbial communities in the distal esophagus are significantly different among groups with a normal esophagus, reflux esophagitis, BE or BAC, despite there being no difference in the bacterial quantity. Considering that microorganism components can be one of the major sources of large amounts of NO, these studies suggest that the bacterial composition in the distal esophagus might play an important role in regulating NO production during the carcinogenic process. Controlling an inflammatory reaction due to gastro-esophageal reflux or bacterial composition around the GEJ might help prevent the progression of Barrett's carcinogenesis by inhibiting NO production.

From Barrett metaplasia to esophageal adenocarcinoma: the molecular background.

The molecular landscape of Barrett's esophagus and Barrett-related neoplastic lesions is still far from being completely elucidated. Both in vitro and in vivo studies pinpointed the pathogenetic role of different morphogenic pathways (the para-homeobox, the Notch and the Sonic Hedgehog families in particular) implicated in the acquisition of the metaplastic phenotype of the esophageal mucosa. On the other hand, the most common genetic alterations observed during Barrett's carcinogenesis include disorders of major regulators of the cell cycle, as well as deregulation of the TGF-β/Smad and receptor tyrosine kinases signalling pathways. Recent comprehensive mutational profiling studies identified that the inactivation of the TP53 and of the SMAD4 tumour suppressor genes occurred in a stage-specific manner, confined to (high grade) dysplastic and neoplastic lesions, respectively. The next step will be the correlation of these findings into multidisciplinary diagnostic approaches integrating endoscopy, histology, molecular profiling and liquid biopsies. This will allow the introduction of innovative strategies for secondary prevention of esophageal adenocarcinoma based on biological rationales, and the implementation of potential novel therapeutic targets.

Animal Models of Barrett's Esophagus and Esophageal Adenocarcinoma-Past, Present, and Future.

Esophageal adenocarcinoma is the fastest rising cancer in the United States. It develops from long-standing gastroesophageal reflux disease which affects >20% of the general population. It carries a very poor prognosis with 5-year survival <20%. The disease is known to sequentially progress from reflux esophagitis to a metaplastic precursor, Barrett's esophagus and then onto dysplasia and esophageal adenocarcinoma. However, only few patients with reflux develop Barrett's esophagus and only a minority of these turn malignant. The reason for this heterogeneity in clinical progression is unknown. To improve patient management, molecular changes which facilitate disease progression must be identified. Animal models can provide a comprehensive functional and anatomic platform for such a study. Rats and mice have been the most widely studied but disease homology with humans has been questioned. No animal model naturally simulates the inflammation to adenocarcinoma progression as in humans, with all models requiring surgical bypass or destruction of existing antireflux mechanisms. Valuable properties of individual models could be utilized to holistically evaluate disease progression. In this review paper, we critically examined the current animal models of Barrett's esophagus, their differences and homologies with human disease and how they have shaped our current understanding of Barrett's carcinogenesis.

509 In Barrett's Epithelial Cells, Lipopolysaccharide (LPS) Induces TLR4 Signaling With Activation of the NLRP3 Inflammasome, Pro-Inflammatory Cytokine Secretion and Pyroptosis: A Potential Role for the Esophageal Microbiome in Barrett's Carcinogenesis

In Barrett's Epithelial Cells, Lipopolysaccharide (LPS) Induces TLR4 Signaling With Activation of the NLRP3 Inflammasome, Pro-Inflammatory Cytokine Secretion and Pyroptosis: A Potential Role for the Esophageal Microbiome in Barrett's Carcinogenesis Yuji Nadatani, Xiaofang Huo, Xi Zhang, Chunhua Yu, Qiuyang Zhang, Edaire Cheng, Toshio Watanabe, Yasuhiro Fujiwara, David H. Wang, Tetsuo Arakawa, Stuart J. Spechler, Rhonda F. Souza

Sa1884 BMP4 Induces SOX9 and Columnar Cytokeratin Expression in Esophageal Squamous Cells and Increases Proliferation in Barrett's Cells Through the p38MAPK Pathway: Potential Roles for BMP4-p38MAPK Signaling in Barrett's Pathogenesis and Carcinogenesis

Sa1884 BMP4 Induces SOX9 and Columnar Cytokeratin Expression in Esophageal Squamous Cells and Increases Proliferation in Barrett's Cells Through the p38MAPK Pathway: Potential Roles for BMP4-p38MAPK Signaling in Barrett's Pathogenesis and Carcinogenesis

Sa1957 Nano-Curcumin Inhibits Neoplastic Process in the Barrett's Epithelial Carcinogenesis Model

Introduction: Curcumin is a natural product commonly used as spice and has attracted considerable attention in recent years due to its great variety of beneficial biological and pharmacological activities. However, one limitation is its low bioavailability because it is almost insoluble in water at acidic or neutral pH. Utilization of nano-technology for the development of efficient anticancer drug delivery is one of the most challenging advances in medicine. Curcumin has been reported to attenuate induction of Cytochrome P450 (CYP) enzymes, and may be responsible for prevention of malignant transformation such as in normal embryonic kidney cells and non-tumorigenic prostate cells. Tobacco and dietary products such as charcoal grilled meat and smoked fish are pro-mutagens because of Benzo[a]pyrene (B[a]P), that undergoes enzymatic metabolism to its ultimate mutagens. This process occurs by induction of extrahepatic CYP members, particularly CYP1A1 and CYP1B1, CYP2U1, and CYP3A4 that are believed to be associated with cancer risk in humans. Using a novel in-vitro model of Barrett's Epithelial Carcinogenesis (BEC) (Int. J. Cancer, 128:274, 2011) we investigated if the carcinogenic process during BE to Esophageal Adenocarcinoma (EAC) is influenced by curcumin. Objective: We investigated the effects of Nano-curcumin against B[a]P induced DNA damage and extrahepatic CYP enzymes on the BEC model cells. Methods: The BEC model is developed by exposing hTERT immortalized benign epithelial cells to HCl (PH4) and glycochenodeoxy cholic acid (200 μM) for 5min/day for 70 weeks leading to transformation of BE cells. . BEC-0 untransformed cells and BEC-70W transformed cells were exposed to 25 μM B[a]P for 48 hrs with or without Nano-curcumin (5μM/30min pre-incubation). Indirect Immunofluorescence was performed to quantify DNA double strand breaks (DSBs) by measuring gamma-H2AX. Real Time qPCR was performed to analyze the expression of CYP1A1, CYP1B1, CYP2U1 and CYP3A4 genes. Fold change was determined by dividing the expression of each target gene to parallel untreated cells. Results: There was a 60% increase (p<0.001) of DSBs on BEC-0 and 47% increase (p<0.001) on BEC70W cells after B[a]P treatment, which can be inhibited (p<0.001) by Nano-curcumin preincubation. Gene expression profile shows a significant increase of CYP1A1, CYP1B1, CYP2U1 and CYP3A4 mRNA transcript after B[a]P treatment on BEC-0 cells, and to a lesser extent on BEC-70W cells. These CYP genes expressions can be inhibited to basal levels by Nano-curcumin. Conclusion: Our results show that Nano-curcumin effectively inhibits B[a]P related DNA damage, and extrahepatic induced CYP enzymes in early stages of the carcinogenesis process. This observation may have chemoprevention possibility in-vivo.

Abstract B05: MRI provides a more reliable method of esophageal tumor detection than endoscopy in a rat model

Abstract Background: The surgical rat model of end-to-side esophagojejunal anastomosis has proven utility in terms of its ability to replicate Barrett's carcinogenesis by inducing gastroduodenoesophageal reflux (GDER). Previously, visual endoscopic analysis has been shown as a valuable tool for monitoring natural history of disease, with biopsy allowing for analysis of molecular markers while avoiding animal sacrifice. However, due to the inherent model limitation of the extraluminal presentation of the majority of tumors, as well as the small size of endoscopic biopsies, adenocarcinoma histology has only been validated post-mortem, and therefore treatment efficacy studies have been limited to chemoprevention. The current study aims to test and establish MRI and / or endoscopic visualization for diagnosis and monitoring of esophageal cancer in the rat model, in order to enhance utilization of this promising de novo model to study treatment response of novel agents in established esophageal cancer. Methods: Chronic bile and acid reflux was induced in 24 Sprague-Dawley rats through a modified Levrat's model. At 40 weeks post-surgery, all animals underwent an endoscopy, T2-weighted turbo spin-echo (TSE) MRI scan and post-mortem histological analysis. A total of five esophageal surgeons and gastroenterologists participated in a blinded study and watched endoscopy videos to determine if esophageal tumor was present. Additionally, three radiology experts participated in a blinded study designed to assess correlated coronal and axial MRI scans and determine whether tumor was present. All videos and scans were studied in triplicate, and histology was used as the gold standard to assess accuracy of each participant's analysis. Results: The accuracy of MRI and endoscopic analysis to correctly identify histology was 69.6% and 57.4%, respectively. The ROC curve analysis showed average MRI rating (AUC = 0.77, p-value = 0.032) was a better discriminator of tumor status in rats than average endoscopy rating (AUC = 0.595, p-value = 0.450). Additionally, false positive rates of MRI and endoscopy were 10.1% and 16.5%, respectively. Inter-observer variability was in substantial agreement for MRI participants (average Kappa = 0.768); whereas endoscopic analysis did not show greater agreement than that what would be expected by chance. All cases where MRI participants agreed on the presence of tumor, histology confirmed the positive findings. Conclusions: MRI is a more reliable diagnostic method than endoscopy for esophageal tumor in rats. Endoscopic examination remains a valuable tool in terms of its ability to biopsy specimens for analysis of biomarker correlates for therapeutic efficacy; however, MRI is a more dependable technique in terms of confirming tumor presence and disease progression for utilization in a treatment model. Citation Format: Juliann E. Kosovec, Yoshihiro Komatsu, Christina L. Rotoloni, Diane V. Thompson, Ali H. Zaidi, Blair A. Jobe. MRI provides a more reliable method of esophageal tumor detection than endoscopy in a rat model. [abstract]. In: Proceedings of the AACR Special Conference: The Translational Impact of Model Organisms in Cancer; Nov 5-8, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2014;12(11 Suppl):Abstract nr B05.

Molecular epidemiology of and genetic susceptibility to esophageal cancer.

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on clonal evolution in Barrett's carcinogenesis; biomarkers for early detection of esophageal cancer; the role of the methylguanine methyl transferase biomarker in the management of adenocarcinoma; and the discovery of high-risk genes in families.

Transcribed ultraconserved noncoding RNAs (T-UCR) are involved in Barrett's esophagus carcinogenesis.

Barrett's esophagus (BE) involves a metaplastic replacement of native esophageal squamous epithelium (Sq) by columnar-intestinalized mucosa, and it is the main risk factor for Barrett-related adenocarcinoma (BAc). Ultra-conserved regions (UCRs) are a class non-coding sequences that are conserved in humans, mice and rats. More than 90% of UCRs are transcribed (T-UCRs) in normal tissues, and are altered at transcriptional level in tumorigenesis. To identify the T-UCR profiles that are dysregulated in Barrett's mucosa transformation, microarray analysis was performed on a discovery set of 51 macro-dissected samples obtained from 14 long-segment BE patients. Results were validated in an independent series of esophageal biopsy/surgery specimens and in two murine models of Barrett's esophagus (i.e. esophagogastric-duodenal anastomosis). Progression from normal to BE to adenocarcinoma was each associated with specific and mutually exclusive T-UCR signatures that included up-regulation of uc.58-, uc.202-, uc.207-, and uc.223- and down-regulation of uc.214+. A 9 T-UCR signature characterized BE versus Sq (with the down-regulation of uc.161-, uc.165-, and uc.327-, and the up-regulation of uc.153-, uc.158-, uc.206-, uc.274-, uc.472-, and uc.473-). Analogous BE-specific T-UCR profiles were shared by human and murine lesions. This study is the first demonstration of a role for T-UCRs in the transformation of Barrett's mucosa.

Sa1839 Atonal Homolog 1 (ATOH1) Upregulates Gastric-and Intestinal-Type Protein Expression in Esophageal Squamous Cells, and Increases Proliferation in Barrett's Cells: Potential Roles for ATOH1 in Barrett's Pathogenesis and Carcinogenesis

in response to DCA treatment. 14% of the K14-Cdx2 mice treated with DCA developed two nodules each at the SCJ, whereas none of the K14-Cdx2 mice receiving water alone developed nodules. In contrast, 70% of the IL-1β mice, and an equal number of Cdx2/IL1β mice developed nodular disease at the SCJ after DCA treatment. All DCA treatmentassociated nodules were histologically consistent with metaplasia. However overall the double-transgenic mice had half as many nodules as IL-1β mice. Cdx2 did not affect IL-1β mRNA levels in the double transgenic mice, nor was the inflammation associated with IL1β expression reduced in the Cdx2/IL-1β mice compared to IL-1β mice, as determined by CD45R+ cell infiltration in the esophagi and forestomach. Moreover, cell proliferation rates were not altered by Cdx2 expression, as EdU incorporation was not significantly different. Lastly, the morphologic appearance of the nodules in all three lines, K14-Cdx2, L2-IL-1β, and K14-Cdx2/L2-IL-1β mice was similar, with abundant alcian blue expressing goblet cells detected, along with expression of other markers of intestinalization. Further molecular characterization of the metaplastic nodules by cDNA microarray profiling is underway. Conclusion: Ectopic expression of Cdx2 in the IL-1Beta mouse model for BE reduces the nodular intestinal metaplasia disease burden. These studies raise new questions as to the specific role of inflammation and intestinal transcription factors in the development of Barrett's esophagus in humans.

Tu1667 Genomic Changes Correlate With Transformed Phenotype in a Dynamic in-Vitro Model of Barrett's Carcinogenesis

Tu1667 Genomic Changes Correlate With Transformed Phenotype in a Dynamic in-Vitro Model of Barrett's Carcinogenesis