Bile Salts at Low pH Cause Dilation of Intercellular Spaces in In Vitro Stratified Primary Esophageal Cells, Possibly by Modulating Wnt Signaling.

BACKGROUND: The presence of dilated intercellular spaces in the stratified squamous lining of the esophagus is the pathognomonic feature of reflux esophagitis secondary to gastroesophageal reflux disease (GERD). In addition to stomach acid, bile salts are major constituents of gastroesophageal refluxate. The aim of our study was to determine the effect of bile salts cocktail at different pHs on epithelial junctions in an in vitro transwell model of stratified esophageal squamous epithelium. DISCUSSION: Human telomerase reverse transcriptase (hTERT) immortalized primary esophageal EPC1 cells were grown on polyester transwell surfaces in calcium-enriched media. The cells exhibited gradual stratification into an 11-layered squamous epithelium over 7 days, together with epithelial barrier function as indicated by increased transepithelial electrical resistance (TEER). This stratified epithelium demonstrated well-formed tight junctions, adherens junctions, and desmosomes as visualized by immunofluorescence and electron microscopy. When exposed to short pulses of bile salts at pH 5, but not either condition alone, there was loss of stratification and decrease in TEER, concomitant with disruption of adherens junctions, tight junctions, and desmosomes, leading to the appearance of dilated intercellular spaces. At the cellular level, bile salts at pH 5 activated the Wnt pathway (indicated by increased ß-catenin Ser552 phosphorylation). CONCLUSION: In conclusion, in our in vitro transwell model bile salts at pH 5, but not bile salts or media at pH 5 alone, modulate Wnt signaling, disrupt different junctional complexes, and cause increased permeability of stratified squamous esophageal epithelium. These changes approximate the appearance of dilated intercellular space similar to that found in GERD patients.

Macrophage subtype predicts lymph node metastasis in oesophageal adenocarcinoma and promotes cancer cell invasion in vitro.

BACKGROUND: Currently, there is a lack of ideal biomarkers for predicting nodal status in preoperative stage of oesophageal adenocarcinoma (EAC) to aid optimising therapeutic options. We studied the potential of applying subtype macrophages to predict lymph node metastasis and prognosis in EAC. MATERIAL AND METHODS: Fifty-three EAC resection specimens were immunostained with CD68, CD40 (M1), and CD163 (M2). Lymphatic vessel density (LVD) was estimated with the staining of D2-40. Subsequently, we tested if M2d macrophage could promote EAC cell migration and invasion. RESULTS: In EAC without neoadjuvant treatment, an increase in M2-like macrophage was associated with poor patient survival, independent of the locations of macrophages in tumour. The M2/M1 ratio that represented the balance between M2- and M1-like macrophages was significantly higher in nodal-positive EACs than that in nodal-negative EACs, and inversely correlated with patient overall survival. The M2/M1 ratio was not related to LVD. EAC cell polarised THP1 cell into M2d-like macrophage, which promoted EAC cell migration and invasion. Neoadjuvant therapy appeared to diminish the correlation between the M2/M1 ratio and survival. CONCLUSIONS: The ratio of M2/M1 macrophage may serve as a sensitive marker to predict lymph node metastasis and poor prognosis in EAC without neoadjuvant therapy. M2d macrophage may have important roles in EAC metastasis.

Quality indicators for the management of Barrett's esophagus, dysplasia, and esophageal adenocarcinoma: international consensus recommendations from the American Gastroenterological Association Symposium.

The development of and adherence to quality indicators in gastroenterology, as in all of medicine, is increasing in importance to ensure that patients receive consistent high-quality care. In addition, government-based and private insurers will be expecting documentation of the parameters by which we measure quality, which will likely affect reimbursements. Barrett's esophagus remains a particularly important disease entity for which we should maintain up-to-date guidelines, given its commonality, potentially lethal outcomes, and controversies regarding screening and surveillance. To achieve this goal, a relatively large group of international experts was assembled and, using the modified Delphi method, evaluated the validity of multiple candidate quality indicators for the diagnosis and management of Barrett's esophagus. Several candidate quality indicators achieved >80% agreement. These statements are intended to serve as a consensus on candidate quality indicators for those who treat patients with Barrett's esophagus.

BMP-driven NRF2 activation in esophageal basal cell differentiation and eosinophilic esophagitis.

Tissue homeostasis requires balanced self-renewal and differentiation of stem/progenitor cells, especially in tissues that are constantly replenished like the esophagus. Disruption of this balance is associated with pathological conditions, including eosinophilic esophagitis (EoE), in which basal progenitor cells become hyperplastic upon proinflammatory stimulation. However, how basal cells respond to the inflammatory environment at the molecular level remains undetermined. We previously reported that the bone morphogenetic protein (BMP) signaling pathway is critical for epithelial morphogenesis in the embryonic esophagus. Here, we address how this pathway regulates tissue homeostasis and EoE development in the adult esophagus. BMP signaling was specifically activated in differentiated squamous epithelium, but not in basal progenitor cells, which express the BMP antagonist follistatin. Previous reports indicate that increased BMP activity promotes Barrett's intestinal differentiation; however, in mice, basal progenitor cell-specific expression of constitutively active BMP promoted squamous differentiation. Moreover, BMP activation increased intracellular ROS levels, initiating an NRF2-mediated oxidative response during basal progenitor cell differentiation. In both a mouse EoE model and human biopsies, reduced squamous differentiation was associated with high levels of follistatin and disrupted BMP/NRF2 pathways. We therefore propose a model in which normal squamous differentiation of basal progenitor cells is mediated by BMP-driven NRF2 activation and basal cell hyperplasia is promoted by disruption of BMP signaling in EoE.

The Durability of Endoscopic Therapy for Treatment of Barrett's Metaplasia, Dysplasia, and Mucosal Cancer After Nissen Fundoplication.

INTRODUCTION: Radiofrequency ablation (RFA) ± endoscopic resection (EMR) is an established treatment strategy for neoplastic Barrett's and intramucosal cancer. Most patients are managed with proton pump inhibitors. The incidence of recurrent Barrett's metaplasia, dysplasia, or cancer after complete eradication is up to 43 % using this strategy. We hypothesize the addition of fundoplication should result in a lower recurrence rates after complete eradication. METHODS: Multi-institutional retrospective review of patients undergoing endotherapy followed by Nissen fundoplication RESULTS: A total of 49 patients underwent RFA ± EMR followed by Nissen fundoplication. Complete remission of intestinal metaplasia (CR-IM) was achieved in 26 (53 %) patients, complete remission of dysplasia (CR-D) in 16 (33 %) patients, and 7 (14 %) had persistent neoplastic Barrett's. After fundoplication, 18/26 (70 %) remained in CR-IM. An additional 10/16 CR-D achieved CR-IM and 4/7 with persistent dysplasia achieved CR-IM. One patient progressed to LGD while no patient developed HGD or cancer. CONCLUSION: Endoscopic therapy for Barrett's dysplasia and/or intramucosal cancer followed by fundoplication results in similar durability of CR-IM to patients being managed with PPIs alone after endoscopic therapy. However, fundoplication may be superior in preventing further progression of disease and the development of cancer. Fundoplication is an important strategy to achieve and maintain CR-IM, and facilitate eradication of persistent dysplasia.

International Consensus on Standardization of Data Collection for Complications Associated With Esophagectomy: Esophagectomy Complications Consensus Group (ECCG).

INTRODUCTION: Perioperative complications influence long- and short-term outcomes after esophagectomy. The absence of a standardized system for defining and recording complications and quality measures after esophageal resection has meant that there is wide variation in evaluating their impact on these outcomes. METHODS: The Esophageal Complications Consensus Group comprised 21 high-volume esophageal surgeons from 14 countries, supported by all the major thoracic and upper gastrointestinal professional societies. Delphi surveys and group meetings were used to achieve a consensus on standardized methods for defining complications and quality measures that could be collected in institutional databases and national audits. RESULTS: A standardized list of complications was created to provide a template for recording individual complications associated with esophagectomy. Where possible, these were linked to preexisting international definitions. A Delphi survey facilitated production of specific definitions for anastomotic leak, conduit necrosis, chyle leak, and recurrent nerve palsy. An additional Delphi survey documented consensus regarding critical quality parameters recommended for routine inclusion in databases. These quality parameters were documentation on mortality, comorbidities, completeness of data collection, blood transfusion, grading of complication severity, changes in level of care, discharge location, and readmission rates. CONCLUSIONS: The proposed system for defining and recording perioperative complications associated with esophagectomy provides an infrastructure to standardize international data collection and facilitate future comparative studies and quality improvement projects.

Neoadjuvant treatment response in negative nodes is an important prognosticator after esophagectomy.

BACKGROUND: The current American Joint Committee on Cancer Seventh Edition (AJCC7) pathologic staging for esophageal adenocarcinoma (EAC) is derived from data assessing the outcomes of patients having undergone esophagectomy without neoadjuvant treatment and has unclear significance in patients who have received multimodality therapy. Lymph nodes with evidence of neoadjuvant treatment effect without residual cancer cells may be observed and are not traditionally considered in pathologic reports, but may have prognostic significance. METHODS: All patients who underwent esophagectomy after completing neoadjuvant therapy for EAC at our institution between 2006 and 2012 were reviewed. Slides of pathologic specimens were reexamined for locoregional treatment-response nodes lacking viable cancer cells but with evidence of acellular mucin pools, central fibrosis, necrosis, or calcifications suggesting prior tumor involvement. Kaplan-Meier survival functions were estimated, and Cox proportional hazards regression models were used to compare staging models. RESULTS: Ninety patients (82 men) underwent esophagectomy after neoadjuvant therapy for EAC (mean age, 61.8 ± 8.9 years). All patients received preoperative chemotherapy, and 50 patients also underwent preoperative radiotherapy. Median Kaplan-Meier survival was 55.6 months, and 5-year survival was 35% (95% confidence interval, 19% to 62%). A total of 100 treatment-response nodes were found in 38 patients. For patients with limited nodal disease (62 ypN0-N1), the presence of treatment-response nodes was associated with significantly worse survival (p = 0.03) compared with patients lacking such nodes. Adjusting for patient age and AJCC7 pathologic stage showed the presence of treatment-response nodes significantly increased the risk of death (hazard ratio, 2.7; 95% confidence interval, 1.1 to 6.9; p = 0.04). When stage-adjusted survival was modeled, counting treatment-response nodes as positive nodes offered a better model fit than ignoring them. CONCLUSIONS: Treatment-response lymph nodes detected from esophagectomy specimens in patients having undergone neoadjuvant chemotherapy or combined chemoradiation for EAC provide valuable prognostic information, particularly in patients with limited nodal disease. The current practice of considering lymph nodes lacking viable cancer cells, but with evidence of tumor necrosis, as pathologically negative likely results in understaging. Future efforts at revising the staging system for EAC should consider incorporating treatment-response lymph nodes in the analysis.

24-h multichannel intraluminal impedance-pH monitoring may be an inadequate test for detecting gastroesophageal reflux in patients with mixed typical and atypical symptoms.

BACKGROUND: The detection of gastroesophageal reflux (GERD) via pH testing is the key component of the evaluation of patients considered for antireflux surgery. Two common pH testing systems exist, a multichannel, intraluminal impedance-pH monitoring (MII-pH) catheter, and wireless (Bravo(®)) capsule; however, discrepancies between the two systems exist. In patients with atypical symptoms, MII-pH catheter is often used preferentially. We aimed to elucidate the magnitude of this discrepancy and to assess the diagnostic value of MII-pH and the Bravo wireless capsule in a population of patients with mixed respiratory and typical symptoms. METHODS: The study population consisted of 66 patients tested with MII-pH and Bravo pH testing within 90 days between July 2009 and 2013. All patients presented with laryngo-pharyngo-respiratory (LPR) symptoms. Patient demographics, symptomatology, manometric and endoscopic findings, and pH monitoring parameters were analyzed. Patients were divided into four comparison groups: both pH tests positive, MII-pH negative/Bravo positive, MII-pH positive/Bravo negative, and both pH tests negative. RESULTS: Nearly half of the patients (44%) had discordant pH test results. Of these, 90% (26/29) had a negative MII-pH but positive Bravo study. In this group, the difference in the DeMeester score was large, a median of 29.3. These patients had a higher BMI (28.5 vs. 26.1, p = 0.0357), were more likely to complain of heartburn (50 vs. 23%, p = 0.0110), to have a hiatal hernia, (85 vs. 53%, p = 0.0075) and a structurally defective lower esophageal sphincter (LES, 85 vs. 58%, p = 0.0208). CONCLUSIONS: In patients with LPR symptoms, we found a high prevalence of discordant esophageal pH results, most commonly a negative MII-pH catheter and positive Bravo. As these patients exhibited characteristics consistent with GERD (heartburn, defective LES, hiatal hernia), the Bravo results are likely true. A 24-h MII-pH catheter study may be inadequate to diagnose GERD in this patient population.

Ambulatory esophageal pH monitoring.

The development and advancement of ambulatory esophageal pH monitoring has provided a key tool with which pathologic esophageal acid exposure can be objectively measured; although not perfect, it provides the clinician with arguably the most important piece of information in the diagnosis and management of patients with gastroesophageal reflux disease. It is also important to emphasize that, although esophageal pH monitoring can reliably measure esophageal acid exposure, assessing the relationship of abnormal findings and the patients' symptoms is a much more complex matter and, of course, the key to successful treatment outcomes.

Cyclin E involved in early stage carcinogenesis of esophageal adenocarcinoma by SNP DNA microarray and immunohistochemical studies.

BACKGROUND: Cyclin E is a cell cycle regulator which is critical for driving G1/S transition. Abnormal levels of cyclin E have been found in many cancers. However, the level changes of cyclin E in esophageal adenocarcinoma and its precancerous lesion have not been well studied. Here, we focus on the gene amplification and expression of cyclin E in these lesions, and aim to ascertain the relationship with clinicopathological characteristics. METHODS: Genomic DNA was analyzed from 116 esophageal adenocarcinoma and 26 precancerous lesion patients using Affymetrix SNP 6.0 arrays. The protein overexpression of cyclin E was also detected using immunohistochemistry from tissue microarrays containing esophageal adenocarcinoma and precancerous lesions. Patient survival and other clinical data were collected and analyzed. The intensity and percentage of the cyclin E expressing cells in tissue microarrays were scored by two pathologists. Fisher exact tests and Kaplan-Meier methods were used to analyze data. RESULTS: By genomic analysis, cyclin E was amplified in 19.0% of the EAC samples. By immunohistochemistry, high expression of cyclin E was observed in 2.3% of squamous mucosa tissues, 3.7% in columnar cell metaplasia, 5.8% in Barrett's esophagus, 19.0% in low grade dysplasia, 35.7% in high grade dysplasia, and 16.7% in esophageal adenocarcinoma. The differences in cyclin E high expression between neoplastic groups and non-dysplasia groups are statistically significant (p < 0.05). The prognosis for patients with high cyclin E expression appeared slightly better than for those with low cyclin E expression although this was not statistically significant (p = 0.13). CONCLUSIONS: The expression of cyclin E significantly increases from non-dysplasia esophageal lesion to low and high grade dysplasia, suggesting that cyclin E plays an important role in the early stage of carcinogenesis. Importantly, cyclin E is also amplified and highly expressed in a subset of esophageal adenocarcinoma patients, but this increase is not associated with worse prognosis.

Comparison of cancer-associated genetic abnormalities in columnar-lined esophagus tissues with and without goblet cells.

OBJECTIVE: To determine and compare the frequency of cancer-associated genetic abnormalities in esophageal metaplasia biopsies with and without goblet cells. BACKGROUND: Barrett's esophagus is associated with increased risk of esophageal adenocarcinoma (EAC), but the appropriate histologic definition of Barrett's esophagus is debated. Intestinal metaplasia (IM) is defined by the presence of goblet cells whereas nongoblet cell metaplasia (NGM) lacks goblet cells. Both have been implicated in EAC risk but this is controversial. Although IM is known to harbor genetic changes associated with EAC, little is known about NGM. We hypothesized that if NGM and IM infer similar EAC risk, then they would harbor similar genetic aberrations in genes associated with EAC. METHODS: Ninety frozen NGM, IM, and normal tissues from 45 subjects were studied. DNA copy number abnormalities were identified using microarrays and fluorescence in situ hybridization. Targeted sequencing of all exons from 20 EAC-associated genes was performed on metaplasia biopsies using Ion AmpliSeq DNA sequencing. RESULTS: Frequent copy number abnormalities targeting cancer-associated genes were found in IM whereas no such changes were observed in NGM. In 1 subject, fluorescence in situ hybridization confirmed loss of CDKN2A and amplification of chromosome 8 in IM but not in a nearby NGM biopsy. Targeted sequencing revealed 11 nonsynonymous mutations in 16 IM samples and 2 mutations in 19 NGM samples. CONCLUSIONS: This study reports the largest and most comprehensive comparison of DNA aberrations in IM and NGM genomes. Our results show that IM has a much higher frequency of cancer-associated mutations than NGM.

Eliminating a need for esophagectomy: endoscopic treatment of Barrett esophagus with early esophageal neoplasia.

Over the past several years, endoscopic ablation and resection have become a new standard of care in the management of Barrett esophagus (BE) with high-grade dysplasia (HGD) or intramucosal adenocarcinoma (IMC). Risk factors for failure of endoscopic therapy and the need for subsequent esophagectomy have not been well elucidated. The aims of this study were to determine the efficacy of radiofrequency ablation (RFA) with or without endoscopic mucosal resection (EMR) in the management of BE with HGD or IMC, to discern factors predictive of endoscopic treatment failure, and to assess the effect of endoscopic therapies on esophagectomy volume at our institution. Data were obtained retrospectively for all patients who underwent endoscopic therapies or esophagectomy for a diagnosis of BE with HGD or IMC in our department between January 1, 2004, and December 31, 2012. Complete remission (CR) of BE or HGD or IMC was defined as 2 consecutive biopsy sessions without BE or HGD or IMC and no subsequent recurrence. Recurrence was defined by the return of BE or HGD or IMC after initial remission. Progression was defined as worsening of HGD to IMC or worsening of IMC to submucosal neoplasia or beyond. Overall, 57 patients underwent RFA with or without EMR for BE with HGD (n = 45) or IMC (n = 12) between 2007 and 2012, with a median follow-up duration of 35.4 months (range: 18.5-52.0 months). The 57 patients underwent 181 ablation sessions and more than half (61%) of patients underwent EMR as a component of treatment. There were no major procedural complications or deaths, with only 2 minor complications including 1 symptomatic stricture requiring dilation. Multifocal HGD or IMC was present in 43% (25/57) of patients. CR of IMC was achieved in 100% (12/12) at a median of 6.1 months, CR of dysplasia was achieved in 79% (45/57) at a median of 11.5 months, and CR of BE was achieved in 49% (28/57) at a median of 18.4 months. Following initial remission, 28% of patients (16/57) had recurrence of dysplasia (n = 12) or BE (n = 4). Progression to IMC occurred in 7% (4/57). All patients without CR continue endoscopic treatment. No patient required esophagectomy or developed metastatic disease. Overall, 6 patients died during the follow-up interval, none from esophageal cancer. Factors associated with failure to achieve CR of BE included increasing length of BE (6.0 ± 0.6 vs 4.0 ± 0.6cm, P = 0.03) and shorter duration of follow-up (28.5 ± 3.8 months vs 49.0 ± 5.8 months, P = 0.004). Shorter surveillance duration (17.8 ± 7.6 months vs 63.9 ± 14.4 months, P = 0.009) and shorter follow-up (21.1 ± 6.1 months vs 43.2 ± 4.1 months) were the only significant factors associated with failure to eradicate dysplasia. Our use of esophagectomy as primary therapy for BE with HGD or IMC has diminished since we began using endoscopic therapies in 2007. From a maximum of 16 esophagectomies per year for early Barrett neoplasia in 2006, we performed only 3 esophageal resections for such early disease in 2012, all for IMC, and we have not performed an esophagectomy for HGD since 2008. Although recurrence of BE or dysplasia/IMC was not uncommon, RFA with or without EMR ultimately resulted in CR of IMC in all patients, CR of HGD in the majority (79%), and CR of BE in nearly half (49%). No patient treated endoscopically for HGD or IMC subsequently required esophagectomy. In patients with BE with HGD or IMC, RFA and EMR are safe and highly effective. The use of endoscopic therapies appears justified as the new standard of care in most cases of BE with early esophageal neoplasia.

Gastroesophageal reflux disease, proton-pump inhibitor use and Barrett's esophagus in esophageal adenocarcinoma: Trends revisited.

PURPOSE: Screening for esophageal adenocarcinoma (EAC) has not become policy in part over concerns in identifying the high-risk group. It is often claimed that a significant proportion of patients developing EAC do not report preexisting reflux symptoms or prior treatment for gastroesophageal reflux disease (GERD). As such, our aim was to assess the prevalence of GERD symptoms, proton pump inhibitor (PPI) use and Barrett's esophagus (BE) and their impact on survival in patients undergoing esophagectomy for EAC. METHODS: The study population consisted of 345 consecutive patients who underwent esophagectomy for EAC between 2000 and 2011 at a university-based medical center. Patients with a diagnosis of esophageal squamous cell carcinoma and those who underwent esophagectomy for benign disease were excluded. The prevalence of preoperative GERD symptoms, defined as presence of heartburn, regurgitation or epigastric pain, PPI use (>6 months) and BE, defined by the phrases "Barrett's esophagus," "intestinal epithelium," "specialized epithelium," or "goblet cell metaplasia" in the patients' preoperative clinical notes were retrospectively collected. Overall long-term and stage-specific survival was compared in patients with and without the presence of preoperative GERD symptoms, PPI use, or BE. RESULTS: The majority of patients (64%; 221/345) had preoperative GERD symptoms and a history of PPI use (52%; 179/345). A preoperative diagnosis of BE was present in 34% (118/345) of patients. Kaplan-Meier survival analysis revealed a marked survival advantage in patients undergoing esophagectomy who had preoperative GERD symptoms, PPI use or BE diagnosis (P ≤ .001). The survival advantage remained when stratified for American Joint Committee on Cancer stage in patients with preoperative PPI use (P = .015) but was less pronounced in patients with GERD symptoms or BE (P = .136 and P = .225, respectively). CONCLUSION: These data show that the oft-quoted statistic that the majority of patients with EAC do not report preexisting GERD or PPI use is false. Furthermore, a diagnosis of BE is present in a surprisingly high proportion of patients (34%). There is a distinct survival advantage in patients with preoperative GERD symptoms, PPI use, and BE diagnosis, which may not be simply owing to earlier stage at diagnosis. Screening may affect survival outcomes in more patients with EAC than previously anticipated.

Preoperative diagnostic workup before antireflux surgery: an evidence and experience-based consensus of the Esophageal Diagnostic Advisory Panel.

BACKGROUND: Gastroesophageal reflux disease (GERD) is a very prevalent disorder. Medical therapy improves symptoms in some but not all patients. Antireflux surgery is an excellent option for patients with persistent symptoms such as regurgitation, as well as for those with complete symptomatic resolution on acid-suppressive therapy. However, proper patient selection is critical to achieve excellent outcomes. STUDY DESIGN: A panel of experts was assembled to review data and personal experience with regard to appropriate preoperative evaluation for antireflux surgery and to construct an evidence and experience-based consensus that has practical application. RESULTS: The presence of reflux symptoms alone is not sufficient to support a diagnosis of GERD before antireflux surgery. Esophageal objective testing is required to physiologically and anatomically evaluate the presence and severity of GERD in all patients being considered for surgical intervention. It is critical to document the presence of abnormal distal esophageal acid exposure, especially when antireflux surgery is considered, and reflux-related symptoms should be severe enough to outweigh the potential side effects of fundoplication. Each testing modality has a specific role in the diagnosis and workup of GERD, and no single test alone can provide the entire clinical picture. Results of testing are combined to document the presence and extent of the disease and assist in planning the operative approach. CONCLUSIONS: Currently, upper endoscopy, barium esophagram, pH testing, and manometry are required for preoperative workup for antireflux surgery. Additional studies with long-term follow-up are required to evaluate the diagnostic and therapeutic benefit of new technologies, such as oropharyngeal pH testing, multichannel intraluminal impedance, and hypopharyngeal multichannel intraluminal impedance, in the context of patient selection for antireflux surgery.

Bile acid at low pH reduces squamous differentiation and activates EGFR signaling in esophageal squamous cells in 3-D culture.

BACKGROUND: Barrett's esophagus is a preneoplastic metaplasia in which the normal squamous epithelium of the esophagus changes to an intestinal, columnar phenotype due to long-term gastro-esophageal reflux. The major components of this reflux are bile and stomach acid. Previous in vitro studies on the effect of bile and acid on esophageal cells have predominantly relied on transformed esophageal squamous cells or cancer cells grown in monolayer culture. DISCUSSION: In this study, we expanded our previous work using an immortalized primary esophageal squamous cell line (EPC1). We demonstrate that EPC1 cells form a multi-layer, stratified epithelium when grown on polyester transwell filters in media supplemented with calcium. When exposed to short pulses of bile and pH 5, but not either condition alone, EPC1 cells demonstrate a reduction in stratification layers and reduced expression of squamous epithelium-specific genes. Bile at pH 5 also causes activation of epidermal growth factor receptor and down-stream pathways. Blocking epidermal growth factor receptor activation partially attenuates the effects of bile acid and pH 5. These results suggest that bile at low pH, but not bile or low pH alone, promotes loss of differentiation status of stratified squamous esophageal epithelium in vitro, possibly by initiating a mucosal repair response through epidermal growth factor activation.

Treatment strategies for esophageal cancer.

The treatment of esophageal cancer has evolved considerably in the past decade and depends largely on the extent of disease at the time of presentation. For disease confined to the esophageal mucosa, endoscopic therapy is replacing esophagectomy as the standard of care. For locoregional disease, neoadjuvant chemoradiation followed by esophagectomy is the best strategy for optimizing long-term survival. In the minority of patents who present with metastatic disease, the prognosis is poor. Palliative therapies available for these patients include chemotherapy, radiation, endoscopic therapies to ameliorate obstruction or bleeding, and surgical intervention to optimize nutritional status or to relieve obstruction.

Sox2 cooperates with inflammation-mediated Stat3 activation in the malignant transformation of foregut basal progenitor cells.

Sox2 regulates the self-renewal of multiple types of stem cells. Recent studies suggest it also plays oncogenic roles in the formation of squamous carcinoma in several organs, including the esophagus where Sox2 is predominantly expressed in the basal progenitor cells of the stratified epithelium. Here, we use mouse genetic models to reveal a mechanism by which Sox2 cooperates with microenvironmental signals to malignantly transform epithelial progenitor cells. Conditional overexpression of Sox2 in basal cells expands the progenitor population in both the esophagus and forestomach. Significantly, carcinoma only develops in the forestomach, where pathological progression correlates with inflammation and nuclear localization of Stat3 in progenitor cells. Importantly, co-overexpression of Sox2 and activated Stat3 (Stat3C) also transforms esophageal basal cells but not the differentiated suprabasal cells. These findings indicate that basal stem/progenitor cells are the cells of origin of squamous carcinoma and that cooperation between Sox2 and microenvironment-activated Stat3 is required for Sox2-driven tumorigenesis.