Acss2/HIF-2 signaling facilitates colon cancer growth and metastasis.

The microenvironment of solid tumors is characterized by oxygen and glucose deprivation. Acss2/HIF-2 signaling coordinates essential genetic regulators including acetate-dependent acetyl CoA synthetase 2 (Acss2), Creb binding protein (Cbp), Sirtuin 1 (Sirt1), and Hypoxia Inducible Factor 2α (HIF-2α). We previously shown in mice that exogenous acetate augments growth and metastasis of flank tumors derived from fibrosarcoma-derived HT1080 cells in an Acss2/HIF-2 dependent manner. Colonic epithelial cells are exposed to the highest acetate levels in the body. We reasoned that colon cancer cells, like fibrosarcoma cells, may respond to acetate in a pro-growth manner. In this study, we examine the role of Acss2/HIF-2 signaling in colon cancer. We find that Acss2/HIF-2 signaling is activated by oxygen or glucose deprivation in two human colon cancer-derived cell lines, HCT116 and HT29, and is crucial for colony formation, migration, and invasion in cell culture studies. Flank tumors derived from HCT116 and HT29 cells exhibit augmented growth in mice when supplemented with exogenous acetate in an Acss2/HIF-2 dependent manner. Finally, Acss2 in human colon cancer samples is most frequently localized in the nucleus, consistent with it having a signaling role. Targeted inhibition of Acss2/HIF-2 signaling may have synergistic effects for some colon cancer patients.

Itraconazole Exerts Its Antitumor Effect in Esophageal Cancer By Suppressing the HER2/AKT Signaling Pathway.

Itraconazole, an FDA-approved antifungal, has antitumor activity against a variety of cancers. We sought to determine the effects of itraconazole on esophageal cancer and elucidate its mechanism of action. Itraconazole inhibited cell proliferation and induced G1-phase cell-cycle arrest in esophageal squamous cell carcinoma and adenocarcinoma cell lines. Using an unbiased kinase array, we found that itraconazole downregulated protein kinase AKT phosphorylation in OE33 esophageal adenocarcinoma cells. Itraconazole also decreased phosphorylation of downstream ribosomal protein S6, transcriptional expression of the upstream receptor tyrosine kinase HER2, and phosphorylation of upstream PI3K in esophageal cancer cells. Lapatinib, a tyrosine kinase inhibitor that targets HER2, and siRNA-mediated knockdown of HER2 similarly suppressed cancer cell growth in vitro Itraconazole significantly inhibited growth of OE33-derived flank xenografts in mice with detectable levels of itraconazole and its primary metabolite, hydroxyitraconazole, in esophagi and tumors. HER2 total protein and phosphorylation of AKT and S6 proteins were decreased in xenografts from itraconazole-treated mice compared to xenografts from placebo-treated mice. In an early phase I clinical trial (NCT02749513) in patients with esophageal cancer, itraconazole decreased HER2 total protein expression and phosphorylation of AKT and S6 proteins in tumors. These data demonstrate that itraconazole has potent antitumor properties in esophageal cancer, partially through blockade of HER2/AKT signaling.

Randomized Trial of Medical versus Surgical Treatment for Refractory Heartburn.

BACKGROUND: Heartburn that persists despite proton-pump inhibitor (PPI) treatment is a frequent clinical problem with multiple potential causes. Treatments for PPI-refractory heartburn are of unproven efficacy and focus on controlling gastroesophageal reflux with reflux-reducing medication (e.g., baclofen) or antireflux surgery or on dampening visceral hypersensitivity with neuromodulators (e.g., desipramine). METHODS: Patients who were referred to Veterans Affairs (VA) gastroenterology clinics for PPI-refractory heartburn received 20 mg of omeprazole twice daily for 2 weeks, and those with persistent heartburn underwent endoscopy, esophageal biopsy, esophageal manometry, and multichannel intraluminal impedance-pH monitoring. If patients were found to have reflux-related heartburn, we randomly assigned them to receive surgical treatment (laparoscopic Nissen fundoplication), active medical treatment (omeprazole plus baclofen, with desipramine added depending on symptoms), or control medical treatment (omeprazole plus placebo). The primary outcome was treatment success, defined as a decrease of 50% or more in the Gastroesophageal Reflux Disease (GERD)-Health Related Quality of Life score (range, 0 to 50, with higher scores indicating worse symptoms) at 1 year. RESULTS: A total of 366 patients (mean age, 48.5 years; 280 men) were enrolled. Prerandomization procedures excluded 288 patients: 42 had relief of their heartburn during the 2-week omeprazole trial, 70 did not complete trial procedures, 54 were excluded for other reasons, 23 had non-GERD esophageal disorders, and 99 had functional heartburn (not due to GERD or other histopathologic, motility, or structural abnormality). The remaining 78 patients underwent randomization. The incidence of treatment success with surgery (18 of 27 patients, 67%) was significantly superior to that with active medical treatment (7 of 25 patients, 28%; P = 0.007) or control medical treatment (3 of 26 patients, 12%; P<0.001). The difference in the incidence of treatment success between the active medical group and the control medical group was 16 percentage points (95% confidence interval, -5 to 38; P = 0.17). CONCLUSIONS: Among patients referred to VA gastroenterology clinics for PPI-refractory heartburn, systematic workup revealed truly PPI-refractory and reflux-related heartburn in a minority of patients. For that highly selected subgroup, surgery was superior to medical treatment. (Funded by the Department of Veterans Affairs Cooperative Studies Program; ClinicalTrials.gov number, NCT01265550.).

Microbial Sensing by Intestinal Myeloid Cells Controls Carcinogenesis and Epithelial Differentiation.

Physiologic microbe-host interactions in the intestine require the maintenance of the microbiota in a luminal compartment through a complex interplay between epithelial and immune cells. However, the roles of mucosal myeloid cells in this process remain incompletely understood. In this study, we identified that decreased myeloid cell phagocytic activity promotes colon tumorigenesis. We show that this is due to bacterial accumulation in the lamina propria and present evidence that the underlying mechanism is bacterial induction of prostaglandin production by myeloid cells. Moreover, we show that similar events in the normal colonic mucosa lead to reductions in Tuft cells, goblet cells, and the mucus barrier of the colonic epithelium. These alterations are again linked to the induction of prostaglandin production in response to bacterial penetration of the mucosa. Altogether, our work highlights immune cell-epithelial cell interactions triggered by the microbiota that control intestinal immunity, epithelial differentiation, and carcinogenesis.

Laparoscopic ischemic conditioning of the stomach increases neovascularization of the gastric conduit in patients undergoing esophagectomy for cancer.

BACKGROUND AND OBJECTIVES: Gastric ischemic preconditioning has been proposed to improve blood flow and reduce the incidence of anastomotic complications following esophagectomy with gastric pull-up. This study aimed to evaluate the effect of prolonged ischemic preconditioning on the degree of neovascularization in the distal gastric conduit at the time of esophagectomy. METHODS: A retrospective review of a prospectively maintained database identified 30 patients who underwent esophagectomy. The patients were divided into three groups: control (no preconditioning, n = 9), partial (short gastric vessel ligation only, n = 8), and complete ischemic preconditioning (left and short gastric vessel ligation, n = 13). Microvessel counts were assessed, using immunohistologic analysis to determine the degree of neovascularization at the distal gastric margin. RESULTS: The groups did not differ in age, gender, BMI, pathologic stage, or cancer subtype. Ischemic preconditioning durations were 163 ± 156 days for partial ischemic preconditioning, compared to 95 ± 50 days for complete ischemic preconditioning (P = 0.2). Immunohistologic analysis demonstrated an increase in microvessel counts of 29% following partial ischemic preconditioning (P = 0.3) and 67% after complete ischemic preconditioning (P < 0.0001), compared to controls. CONCLUSIONS: Our study indicates that prolonged ischemic preconditioning is safe and does not interfere with subsequent esophagectomy. Complete ischemic preconditioning increased neovascularization in the distal gastric conduit.

Clinical Implications of Histologic Abnormalities in Ileocolonic Biopsies of Patients With Crohn's Disease in Remission.

BACKGROUND: For patients with Crohn's disease (CD) who have colonoscopy during periods of clinical remission, the utility of taking ileocolonic biopsy specimens to assess disease activity is disputed. GOALS: We explored the clinical implications of histologic disease activity in such patients. STUDY: We reviewed medical records of CD patients who underwent elective colonoscopy while in clinical remission at our VA Medical Center from 2000 to 2013, and who had at least 6 months of follow-up. We correlated endoscopic and histologic disease activity with the subsequent development of flares. RESULTS: We identified 62 CD patients who had a total of 103 colonoscopies during clinical remission; 55 colonoscopies revealed complete endoscopic healing and 48 showed active disease. Flares within 6, 12, and 24 months of colonoscopy were not more common in patients with endoscopic activity than those with complete endoscopic healing. In contrast, patients with any of 5 histologic features of active inflammation (erosions, cryptitis, crypt abscess, increased neutrophils, or increased eosinophils in the lamina propria) had more flares than patients without those changes (P<0.05). Among the individual histologic features, an increase in eosinophils or neutrophils in the lamina propria and cryptitis were associated with higher flare rates (P<0.05). CONCLUSIONS: For CD patients who have a colonoscopy while in clinical remission, biopsy seems to provide important prognostic information beyond that provided by endoscopic assessment of disease activity alone. In particular, increased eosinophils or neutrophils in the lamina propria and cryptitis are strongly associated with an increased risk of clinical flares within 1 to 2 years.

Digital Papillary Adenocarcinoma: Presentation, Natural History and Management.

Digital papillary adenocarcinoma (DPA) is a rare malignant tumor of the sweat glands that often presents as a solitary painless mass on the digits of the hands or feet. We present a rare case of DPA on the ankle in a 54 year-old African American man. Although the most common location for digital papillary adenocarcinoma is on the hands and feet, it can present in other locations. Treatment modalities and concerns such as the level of margin resection, degree of negative margins, and the need for a sentinel lymph node biopsy might be different if the tumor is encountered in locations other than the digits. In the following manuscript, we discuss the natural history of this rare tumor including a review of the current literature with emphasis on documented treatment strategies as well as the approach in treating patients with a unique presentation.

Copper metabolism domain-containing 1 represses genes that promote inflammation and protects mice from colitis and colitis-associated cancer.

BACKGROUND & AIMS: Activation of the transcription factor nuclear factor-κB (NF-κB) has been associated with the development of inflammatory bowel disease (IBD). Copper metabolism MURR1 domain containing 1 (COMMD1), a regulator of various transport pathways, has been shown to limit NF-κB activation. We investigated the roles of COMMD1 in the pathogenesis of colitis in mice and IBD in human beings. METHODS: We created mice with a specific disruption of Commd1 in myeloid cells (Mye-knockout [K/O] mice); we analyzed immune cell populations and functions and expression of genes regulated by NF-κB. Sepsis was induced in Mye-K/O and wild-type mice by cecal ligation and puncture or intraperitoneal injection of lipopolysaccharide (LPS), colitis was induced by administration of dextran sodium sulfate, and colitis-associated cancer was induced by administration of dextran sodium sulfate and azoxymethane. We measured levels of COMMD1 messenger RNA in colon biopsy specimens from 29 patients with IBD and 16 patients without (controls), and validated findings in an independent cohort (17 patients with IBD and 22 controls). We searched for polymorphisms in or near COMMD1 that were associated with IBD using data from the International IBD Genetics Consortium and performed quantitative trait locus analysis. RESULTS: In comparing gene expression patterns between myeloid cells from Mye-K/O and wild-type mice, we found that COMMD1 represses expression of genes induced by LPS. Mye-K/O mice had more intense inflammatory responses to LPS and developed more severe sepsis and colitis, with greater mortality. More Mye-K/O mice with colitis developed colon dysplasia and tumors than wild-type mice. We observed a reduced expression of COMMD1 in colon biopsy specimens and circulating leukocytes from patients with IBD. We associated single-nucleotide variants near COMMD1 with reduced expression of the gene and linked them with increased risk for ulcerative colitis. CONCLUSIONS: Expression of COMMD1 by myeloid cells has anti-inflammatory effects. Reduced expression or function of COMMD1 could be involved in the pathogenesis of IBD.

Clinical implications of histologic abnormalities in colonic biopsy specimens from patients with ulcerative colitis in clinical remission.

BACKGROUND: For patients with ulcerative colitis (UC) who have colonoscopy while their disease is in clinical remission, the clinical implications of finding histologic abnormalities of colitis are not clear. METHODS: We reviewed the medical records of patients with UC who had elective colonoscopy at our VA Medical Center while their UC was in clinical remission and who had at least 6 months of follow-up data available. The Mayo endoscopic subscore was used to assess endoscopic disease activity. Biopsies were evaluated for specific changes in the following general categories: acute inflammation, chronic inflammation, epithelial damage, and architectural distortion. RESULTS: We identified 51 patients with UC who had a total of 84 colonoscopies (at least 1 year apart) while they were in clinical remission. Forty colonoscopies revealed no endoscopic activity (Mayo subscore 0) and 44 showed endoscopic activity (Mayo subscore 1, 2, or 3). Although flares were approximately twice as common in patients with endoscopic activity as in those with an endoscopically normal mucosa, the difference was not statistically significant. On histologic evaluation, in contrast, the presence of basal lymphoplasmacytosis, basally located lymphoid aggregates, erosions and/or ulcerations of the epithelium, or moderate to marked architectural distortion all were significant predictors of clinical flares by 6 and 12 months. CONCLUSIONS: For patients with UC who have colonoscopy while their disease is in clinical remission, colonic biopsy seems to provide important prognostic information beyond that provided by the endoscopic assessment of disease activity alone.

Histopathologic diagnosis of eosinophilic conditions in the gastrointestinal tract.

Eosinophils, a constitutive component of the columnar-lined gastrointestinal tract, play an essential role in allergic responses and parasitic infections. The tissue density of these cells also increases in a variety of conditions of uncertain etiology. With the exception of the esophageal squamous epithelium, in which no eosinophils are normally present, the population of normal eosinophils in the remainder of the luminal gut is poorly defined. Therefore, histopathologists must rely on their subjective judgment to determine when a diagnosis of eosinophilic gastritis, enteritis, or colitis should be rendered. Eosinophilic esophagitis is currently the best defined and most studied eosinophilic condition of the digestive tract; therefore, the confidence in accurate diagnosis is increasing. In contrast, the characteristic clinicopathologic features of eosinophilic conditions affecting other parts of the digestive tract remain somewhat elusive. This review was designed to present pathologists with simple and practical information for the biopsy-based histopathologic diagnosis of eosinophilic esophagitis, gastritis, enteritis, and colitis. It was prepared by critically reviewing more than 200 articles on the topic, along with incorporating evidence accumulated through our own collective experience. We anticipate that by increasing pathologists' confidence in reporting these abnormal but often nameless eosinophilic infiltrates, we can help better define and characterize their significance.

Absence of focally enhanced gastritis in macaques with idiopathic colitis.

BACKGROUND: Focally enhanced gastritis has been described in association with Crohn's disease and ulcerative colitis, but is rare in the general population. The study aim was to test whether idiopathic colitis in macaques was associated with any characteristic changes of the gastric mucosa resembling similar changes in humans. METHODS: The presence or absence of idiopathic colitis was established by gross and microscopic examination of the colons of rhesus macaques (Macaca mulatta), which died at the Oregon National Primate Research Center. Gastric tissue specimens were compared between a case population of 26 macaques with idiopathic colitis and a control population of 21 macaques without colitis. The specimens were histologically assessed by two independent pathologists blinded to the presence or absence of idiopathic colitis. Differences between cases and controls were compared using a two-sided Fisher's exact test. RESULTS: Of the 26 cases of macaques with colitis, 11 animals (42%) harbored signs of chronic gastritis. Of the 21 control macaques without colitis, nine animals (43%) harbored signs of chronic gastritis, P = 1.0000. Of all animals with gastritis, 1/11 animals with colitis and 2/9 control animals showed rare active gastritis as evidenced by the presence of neutrophils, P = 0.5658. Lymphocytic infiltrates of the gastric mucosa were seen in 4/11 colitis cases and 0/9 controls, P = 0.0942. No gastric specimens with focally enhanced gastritis were found among any of the case or control animals. CONCLUSIONS: Unlike chronic inflammatory bowel disease in humans, idiopathic colitis in macaques is not associated with focally enhanced gastritis or any other type of specific gastritis.

Frequent occurrence of gastritis and duodenitis in patients with inflammatory bowel disease.

BACKGROUND: The purpose was to study the epidemiology of Helicobacter-negative gastritis among a large group of patients with inflammatory bowel disease (IBD) and healthy controls. METHODS: From a computerized database of surgical pathology reports we selected 5493 patients who underwent colonoscopy and upper gastrointestinal endoscopy with biopsy results from both procedures. The presence of gastritis and duodenitis was compared among 550 case subjects with IBD and 4943 healthy control subjects. The results are expressed as prevalence rates, as well as age- and sex-adjusted odds ratios with 95% confidence intervals. RESULTS: Any type gastritis was found in 13% of controls and 25% of IBD patients (Crohn's disease [CD] 33%, ulcerative colitis [UC] 19%). Duodenitis was found in 1% of controls and 13% of IBD patients (CD 26%, UC 3%). In subjects younger than 18 years the prevalence of gastritis and duodenitis were 53% and 40% in CD, respectively, and 38% and 0% in UC, respectively. Similar prevalence rates were found in men and women. The odds ratio for Helicobacter-negative chronic active gastritis associated with CD was 11.7 (7.5-18.0) and with UC 2.8 (1.4-5.0). The corresponding values for focally enhanced gastritis were 40.1 (15.5-114.9) in CD and 0 in UC. CONCLUSIONS: Helicobacter-negative gastritis and duodenitis occur significantly more often in patients with IBD than healthy controls. Such upper gastrointestinal inflammation appears to be particularly common in CD and younger patients.

Ileal biopsy: Clinical indications, endoscopic and histopathologic findings in 10,000 patients.

BACKGROUND: Ileal biopsies are often reported as having a low yield. Data from endoscopy practices in the private setting are lacking. AIMS: To correlate the frequency of histologic abnormalities in ileal biopsies with clinical indications and ileoscopic appearances. METHODS: Retrospective analysis of clinical, endoscopic, and histopathologic data from a large database. RESULTS: We studied 9785 unique adult patients (median age 46 years, 61.4% women) with ileal biopsies. The most common symptoms were diarrhoea (52.2%) and abdominal pain (37.1%). Ileoscopy was reported as being normal in 75.1% patients. Subjects screened for cancer had the highest prevalence of abnormal endoscopic findings (63.3%); patients with known or suspected Crohn's had the highest prevalence abnormal ileal histology (36.4%). Overall, 5.0% of ileal biopsies obtained from patients with normal endoscopy and 47.4% of biopsies from patients with an endoscopically abnormal ileum had significant histopathologic findings. CONCLUSIONS: In adults, biopsies from the endoscopically normal ileum rarely provide clinically relevant information and cannot be recommended. In contrast, half of the adult patients with an endoscopically abnormal ileum have significant histopathologic findings in ileal biopsies. Therefore, ileoscopy associated with a sensible use of the ileal biopsy is a valuable complement to the colonoscopy.

Eosinophilic gastritis: histopathological characterization and quantification of the normal gastric eosinophil content.

There is limited information about normal eosinophil counts in the gastric mucosa. The purpose of this study was to evaluate the histopathology of 60 patients whose biopsies showed increased eosinophils in the gastric mucosa. We also investigated the eosinophil content in gastric biopsies from normal controls (matched for age, sex, and zip code), from patients with Helicobacter pylori gastritis, and patients with Crohn's disease. Eosinophils were counted in five random high-power fields (HPFs) and reported in eosinophils/mm(2). Involvement of the muscularis mucosae or submucosa, sheets of eosinophils, and infiltration of the gastric epithelium were also evaluated. The median eosinophil count in the study patients was 539 eosinophils/mm(2); mean±SD=653±418 eosinophils/mm(2); range 127-2108. Sheets of eosinophils were seen in 38 patients, 27 showed involvement of the muscularis mucosae or submucosa. There were 7 patients without epithelial infiltration by eosinophils, whereas 34 were tallied as rare and 19 were scored as abundant. No study patient had no evidence of H. pylori. The mean eosinophil count for the 135 normal controls was 15.5±16.8 SD eosinophils/mm(2) (range 0-110); in the 93 controls with H. pylori gastritis the mean eosinophil count was 25±32.6 SD eosinophils/mm(2) (range 0-219); and for the 53 controls with Crohn's disease it was 31.4±44.4 SD eosinophils/mm(2) (range 0-203). There were no significant differences between the counts in biopsies from the antrum and corpus, and no significant variations by age, geographic location, or season. This study confirms that, in the United States population, the normal gastric eosinophilic counts are usually <38 eosinophils/mm(2). We recommend 'histological eosinophilic gastritis' for the diagnosis of gastric biopsies that show an average density ≥127 eosinophils/mm(2) (or ≥30 eosinophils per HPF) in at least five HPFs in the absence of known associated causes of eosinophilia.

Gastric cardiac polyps: a clinicopathologic study of 330 cases.

As endoscopists have become more skilled in sampling the gastroesophageal junction, pathologists are being increasingly challenged to characterize previously unknown or neglected findings. One such example is the cardiac polyp. Originally described in the radiology literature as the sentinel fold, the first histologic descriptions of polyps at the gastroesophageal junction did not appear until less than a decade ago. Current clinicopathologic information is limited and somewhat conflicting. This study was designed to define the clinical, endoscopic, and histopathologic associations in patients with cardiac polyps. Using an electronic database, we extracted information on all patients who had a distal esophageal or esophagogastric junctional biopsy during a 24-month period. We then reviewed the slides of 330 adult patients diagnosed with a cardiac polyp and used semiquantitative or qualitative scales to score foveolar hyperplasia, inflammation, erosion or ulcers, epithelial type, and metaplasia. As controls we used 120,487 patients who had biopsies from the same anatomic sites during the same period, but were not diagnosed with a cardiac polyp. There were no significant differences among any clinical indications for esophagogastroduodenoscopy between study and control patients. Endoscopically, a polyp or nodule at the gastroesophageal junction was noted in 59.1% of the patients who had a histopathologic diagnosis of cardiac polyp. Histologically, Barrett mucosa, active esophagitis, and Helicobactor pylori gastritis were all significantly less common in patients with a cardiac polyp than in controls. Although relatively infrequent, synchronous hyperplastic polyps elsewhere in the stomach were significantly more common in patients than in controls. In conclusion, this large series suggests that cardiac polyps are rare but histologically distinct lesions. They are benign and are not uniquely associated with esophagitis, Barrett esophagus, gastroesophageal reflux disease, reactive gastropathy, or gastritis, with or without H. pylori.

Malignant transformation of non-neoplastic Barrett's epithelial cells through well-defined genetic manipulations.

BACKGROUND: Human Barrett's cancer cell lines have numerous, poorly-characterized genetic abnormalities and, consequently, those lines have limited utility as models for studying the early molecular events in carcinogenesis. Cell lines with well-defined genetic lesions that recapitulate various stages of neoplastic progression in Barrett's esophagus would be most useful for such studies. METHODOLOGY/PRINCIPAL FINDINGS: To develop such model cell lines, we started with telomerase-immortalized, non-neoplastic Barrett's epithelial (BAR-T) cells, which are spontaneously deficient in p16, and proceeded to knock down p53 using RNAi, to activate Ras by introducing oncogenic H-Ras(G12V), or both. BAR-T cells infected with either p53 RNAi or oncogenic H-Ras(G12V) alone maintained cell-to-cell contact inhibition and did not exhibit anchorage-independent growth in soft agar. In contrast, the combination of p53 RNAi knockdown with expression of oncogenic H-Ras(G12V) transformed the p16-deficient BAR-T cells, as evidenced by their loss of contact inhibition, by their formation of colonies in soft agar, and by their generation of tumors in immunodeficient mice. CONCLUSIONS/SIGNIFICANCE: Through these experiments, we have generated a number of transformed and non-transformed cell lines with well-characterized genetic abnormalities recapitulating various stages of carcinogenesis in Barrett's esophagus. These lines should be useful models for the study of carcinogenesis in Barrett's esophagus, and for testing the efficacy of chemopreventive and chemotherapeutic agents.

Biomarkers and molecular diagnosis of gastrointestinal and pancreatic neoplasms.

Standard protocols for the diagnosis of neoplasms in the gastrointestinal tract are based on histopathologic analysis in combination with clinical information. With the completion of the Human Genome Project in 2003, our understanding of the contribution of genetics to human disease has increased exponentially. This knowledge is gradually being incorporated into clinical decision-making. However, the rate at which molecular biomarkers are validated for use in mainstream clinical applications has lagged far behind that of biomarker discovery. Nevertheless, a number of molecular biomarkers are available for use in the diagnosis and management of gastrointestinal tract neoplasms. This article reviews the most common molecular biomarkers currently available for neoplasms of the luminal gastrointestinal tract and pancreas. In neoplasms of the esophagus, for which no biomarkers are currently used in routine clinical practice, those that have shown the most promise in early clinical validation studies are discussed.

Acid and bile salt-induced CDX2 expression differs in esophageal squamous cells from patients with and without Barrett's esophagus.

BACKGROUND & AIMS: It is not clear why only a minority of patients with gastroesophageal reflux disease (GERD) develop Barrett's esophagus. We hypothesized that differences among individuals in molecular pathways activated when esophageal squamous epithelium is exposed to reflux underlie the development of Barrett's metaplasia. METHODS: We used esophageal squamous cell lines from patients who had GERD with Barrett's esophagus (normal esophageal squamous [NES]-B3T and NES-B10T) and without Barrett's esophagus (NES-G2T and NES-G4T) to study effects of acid and bile salts on expression of the CDX2 gene. Bay 11-705, Ad5 inhibitor kappaB(IkappaB)alpha-SR, and site-directed mutagenesis were used to explore effects of nuclear factor-kappaB (NF-kappaB) inhibition on CDX2 promoter activity; DNA binding of the NF-kappaB subunits p50 and p65 was assessed by chromatin immune-precipitation. RESULTS: Acid and bile salts increased CDX2 messenger RNA (mRNA), protein, and promoter activity in NES-B3T and NES-B10T cells, but not in NES-G2T or NES-G4T cells. Inhibition of NF-kappaB abolished the increase in CDX2 promoter activity. Increased CDX2 promoter activity was associated with nuclear translocation of p50, which bound to the promoter. We found CDX2 mRNA in 7 of 10 esophageal squamous biopsy specimens from patients with Barrett's esophagus, but in only 1 of 10 such specimens from patients who had GERD without Barrett's esophagus. CONCLUSIONS: Acid and bile salts induce CDX2 mRNA and protein expression in esophageal squamous cells from patients with Barrett's esophagus, but not from GERD patients without Barrett's esophagus. We speculate that these differences in acid- and bile salt-induced activation of molecular pathways may underlie the development of Barrett's metaplasia.