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Silberg DG, Dubow J, Bast A. Randomized Controlled Trials in Celiac Disease: Expressing the Patient's Voice. Gastroenterology 2024; 166:941-942. [PMID: 38242236 DOI: 10.1053/j.gastro.2024.01.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 01/11/2024] [Indexed: 01/21/2024]
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VOS MIRIAMB, Dimick-Santos L, Mehta R, Omokaro SO, Taminiau J, Schabel E, Kleiner DE, Szitanyi P, Socha P, Schwimmer JB, Noviello S, Silberg DG, Torstenson R, Miller V, Lavine JE, Baldyga W, Banerjee R, Behling C, Boulos S, Burgess G, Calboli D, Charles E, Christian R, Cohen-Bacrie C, Cosma-Roman D, Danzer CP, Delaet I, Delegge M, Dimick-Santos L, DiProspero N, Donohue K, Fischer L, Fitzpatrick E, Fried M, Hagerty D, Hale P, Hildick K, Hum D, Jamil K, Jiang L, Karpen S, Kelly M, Kleiner DE, Kohli R, Kordy K, Krieger N, Lavine J, Lee L, Lefebvre E, Lopez P, Lyons E, Malahias L, Megnien S, Mehta R, Mesenbrink P, Miller V, Minnick P, Murray C, Nghiem T, Nicholson N, Noviello S, Omokaro SO, Pang W, Percival L, Peres D, Powell M, Roman D, Root M, Sampson C, Sanyal A, Schabel E, Schwarz K, Schwimmer JB, Seyedkazemi S, Shapiro D, Shringarpure R, Silberg D, Smith E, Socha P, Squires R, Szitanyi P, Taminiau J, Torstenson R, Treem W, Vig P, Vos M, Yamashita M, Zemel M. Factors to Consider in Development of Drugs for Pediatric Nonalcoholic Fatty Liver Disease. Gastroenterology 2019; 157:1448-1456.e1. [PMID: 31520612 PMCID: PMC8996263 DOI: 10.1053/j.gastro.2019.08.048] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 08/13/2019] [Accepted: 08/17/2019] [Indexed: 02/07/2023]
Affiliation(s)
- MIRIAM B. VOS
- Emory University School of Medicine, Atlanta, Georgia
| | | | - Ruby Mehta
- US Food and Drug Administration, Bethesda, Maryland
| | | | | | - Elmer Schabel
- Bundesinstitut für Arzneimittel und Medizinprodukte, Bonn, Germany
| | - David E Kleiner
- National Cancer Institute, Center for Cancer Research, Bethesda, Maryland
| | - Peter Szitanyi
- General University Hospital, Charles University, Prague, Czech Republic
| | - Piotr Socha
- Children's Memorial Health Institute, Warsaw, Poland
| | - Jeffrey B Schwimmer
- University of California, San Diego School of Medicine, La Jolla, California
| | | | | | | | | | - Joel E Lavine
- Columbia University Medical Center, New York, New York.
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Siebers N, Palmer M, Silberg DG, Jennings L, Bliss C, Martin PT. Absorption, Distribution, Metabolism, and Excretion of [ 14C]-Volixibat in Healthy Men: Phase 1 Open-Label Study. Eur J Drug Metab Pharmacokinet 2018; 43:91-101. [PMID: 28702877 PMCID: PMC5794849 DOI: 10.1007/s13318-017-0429-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Background and Objectives Volixibat is a potent inhibitor of the apical sodium-dependent bile acid transporter in development for the treatment of nonalcoholic steatohepatitis. This phase 1, open-label study investigated the absorption, distribution, metabolism, and excretion of [14C]-volixibat in heathy men. Methods Eligible men (n = 8) aged 18–50 years (body mass index 18.0–30.0 kg/m2; weight >50 kg) received a single oral dose of [14C]-volixibat 50 mg containing ~5.95 µCi radioactivity. The primary objectives were to assess the pharmacokinetics of [14C]-volixibat and to determine the total radioactivity in whole blood, plasma, urine, and feces at pre-selected time points over 6 days. The secondary objectives were to characterize metabolites and to assess the safety and tolerability. Results Low concentrations of volixibat (range 0–0.179 ng/mL) were detected in plasma up to 8 h following administration; the pharmacokinetic parameters could not be calculated. No radioactivity was observed in plasma or whole blood. The percentage (mean ± standard deviation) of total radioactivity in urine was 0.01 ± 0.007%. The vast majority (92.3 ± 5.25%) of volixibat was recovered in feces (69.2 ± 33.1% within 24 h). Unchanged volixibat was the only radioactive component detected in feces. Adverse events were mild in severity and mostly gastrointestinal. Changes in laboratory values were not clinically meaningful. Conclusions Following oral administration, [14C]-volixibat was excreted unchanged from the parent compound almost exclusively via fecal excretion, indicating that the drug is minimally absorbed. Consistent with other studies, adverse events were primarily gastrointestinal in nature. ClinicalTrials.gov identifier NCT02571192. Electronic supplementary material The online version of this article (doi:10.1007/s13318-017-0429-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Nicholas Siebers
- Covance Clinical Research Unit, 3402 Kinsman Boulevard, Madison, WI, 53704, USA.
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Taylor F, Reasner DS, Carson RT, Deal LS, Foley C, Iovin R, Lundy JJ, Pompilus F, Shields AL, Silberg DG. Development of a Symptom-Based Patient-Reported Outcome Instrument for Functional Dyspepsia: A Preliminary Conceptual Model and an Evaluation of the Adequacy of Existing Instruments. Patient 2018; 9:409-18. [PMID: 27020447 PMCID: PMC5021747 DOI: 10.1007/s40271-016-0164-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVES The aim was to document, from the perspective of the empirical literature, the primary symptoms of functional dyspepsia (FD), evaluate the extent to which existing questionnaires target those symptoms, and, finally, identify any missing evidence that would impact the questionnaires' use in regulated clinical trials to assess treatment efficacy claims intended for product labeling. METHODS A literature review was conducted to identify the primary symptoms of FD and existing symptom-based FD patient-reported outcome (PRO) instruments. Following a database search, abstracts were screened and articles were retrieved for review. The primary symptoms of FD were organized into a conceptual model and the PRO instruments were evaluated for conceptual coverage as well as compared against evidentiary requirements presented in the FDA's PRO Guidance for Industry. RESULTS Fifty-six articles and 16 instruments assessing FD symptoms were reviewed. Concepts listed in the Rome III criteria for FD (n = 7), those assessed by existing FD instruments (n = 34), and symptoms reported by patients in published qualitative research (n = 6) were summarized in the FD conceptual model. Except for vomiting, all of the identified symptoms from the published qualitative research reports were also specified in the Rome III criteria. Only three of the 16 instruments, the Dyspepsia Symptom Severity Index (DSSI), Nepean Dyspepsia Index (NDI), and Short-Form Nepean Dyspepsia Index (SF-NDI), measure all seven FD symptoms defined by the Rome III criteria. Among these three, each utilizes a 2-week recall period and 5-point Likert-type scale, and had evidence of patient involvement in development. Despite their coverage, when these instruments were evaluated in light of regulatory expectations, several issues jeopardized their potential qualification for substantiation of a labeling claim. CONCLUSIONS No existing PRO instruments that measured all seven symptoms adhered to the regulatory principles necessary to support product labeling. As such, the development of a new FD symptom PRO instrument is supported.
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Affiliation(s)
| | - David S Reasner
- Study Endpoints, Ironwood Pharmaceuticals, Inc., 301 Binney Street, Cambridge, MA, 02142, USA.
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Palmer M, Jennings L, Silberg DG, Bliss C, Martin P. A randomised, double-blind, placebo-controlled phase 1 study of the safety, tolerability and pharmacodynamics of volixibat in overweight and obese but otherwise healthy adults: implications for treatment of non-alcoholic steatohepatitis. BMC Pharmacol Toxicol 2018; 19:10. [PMID: 29548345 PMCID: PMC5857122 DOI: 10.1186/s40360-018-0200-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 03/07/2018] [Indexed: 12/13/2022] Open
Abstract
Background Accumulation of toxic free cholesterol in hepatocytes may cause hepatic inflammation and fibrosis. Volixibat inhibits bile acid reuptake via the apical sodium bile acid transporter located on the luminal surface of the ileum. The resulting increase in bile acid synthesis from cholesterol could be beneficial in patients with non-alcoholic steatohepatitis. This adaptive dose-finding study investigated the safety, tolerability, pharmacodynamics, and pharmacokinetics of volixibat. Methods Overweight and obese adults were randomised 3:1 to double-blind volixibat or placebo, respectively, for 12 days. Volixibat was initiated at a once-daily dose of 20 mg, 40 mg or 80 mg. Based on the assessment of predefined safety events, volixibat dosing was either escalated or reduced. Other dose regimens (titrations and twice-daily dosing) were also evaluated. Assessments included safety, tolerability, stool hardness, faecal bile acid (FBA) excretion, and serum levels of 7α-hydroxy-4-cholesten-3-one (C4) and lipids. Results All 84 randomised participants (volixibat, 63; placebo, 21) completed the study, with no serious adverse events at doses of up to 80 mg per day (maximum assessed dose). The median number of daily bowel evacuations increased from 1 (range 0–4) to 2 (0–8) during volixibat treatment, and stool was looser with volixibat than placebo. Volixibat was minimally absorbed; serum levels were rarely quantifiable at any dose or sampling time point, thereby precluding pharmacokinetic analyses. Mean daily FBA excretion was 930.61 μmol (standard deviation [SD] 468.965) with volixibat and 224.75 μmol (195.403) with placebo; effects were maximal at volixibat doses ≥20 mg/day. Mean serum C4 concentrations at day 12 were 98.767 ng/mL (standard deviation, 61.5841) with volixibat and 16.497 ng/mL (12.9150) with placebo. Total and low-density lipoprotein cholesterol levels decreased in the volixibat group, with median changes of − 0.70 mmol/L (range − 2.8 to 0.4) and − 0.6990 mmol/L (− 3.341 to 0.570), respectively. Conclusions This study indicates that maximal inhibition of bile acid reabsorption, as assessed by FBA excretion, occurs at volixibat doses of ≥20 mg/day in obese and overweight adults, without appreciable change in gastrointestinal tolerability. These findings guided dose selection for an ongoing phase 2 study in patients with non-alcoholic steatohepatitis. Trial registration ClinicalTrials.gov identifier: NCT02287779 (registration first received 6 November 2014). Electronic supplementary material The online version of this article (10.1186/s40360-018-0200-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Melissa Palmer
- Global Development Lead Hepatology, Shire, 300 Shire Way, Lexington, MA, 02421, USA.
| | - Lee Jennings
- Global Development Lead Hepatology, Shire, 300 Shire Way, Lexington, MA, 02421, USA
| | - Debra G Silberg
- Shire International GmbH, Zahlerweg 10, 6301, Zug, Switzerland
| | - Caleb Bliss
- Global Development Lead Hepatology, Shire, 300 Shire Way, Lexington, MA, 02421, USA
| | - Patrick Martin
- Global Development Lead Hepatology, Shire, 300 Shire Way, Lexington, MA, 02421, USA
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Fuller G, Bolus R, Whitman C, Talley J, Erder MH, Joseph A, Silberg DG, Spiegel B. PRISM, a Patient-Reported Outcome Instrument, Accurately Measures Symptom Change in Refractory Gastroesophageal Reflux Disease. Dig Dis Sci 2017; 62:593-606. [PMID: 28116591 DOI: 10.1007/s10620-016-4440-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 12/29/2016] [Indexed: 12/22/2022]
Abstract
BACKGROUND Most patients with gastroesophageal reflux disease (GERD) experience relief following treatment with proton pump inhibitors (PPIs) (Vakil et al. in Am J Gastroenterol 101:1900-1920, 2006; Everhart and Ruhl in Gastroenterology 136:376-386, 2009). As many as 17-44% of patients, however, exhibit only partial response to therapy. Most extant GERD patient-reported outcome (PRO) instruments fail to meet development best practices as described by the FDA (Talley and Wiklund in Qual Life Res 14:21-33, 2005; Van Pinxteren et al. in Cochrane Database Syst Rev 18:CD002095, 2004; El-Serag et al. in Aliment Pharmacol Ther 32:720-737, 2010). AIM To develop and validate a PRO instrument for clinical trials involving patients with GERD who are PPI partial responders. METHODS We prepared a systematic literature review, held patient focus groups, convened an expert panel, and conducted cognitive interviews to establish content validity. Eligible participants took PPI therapy for at least 8 weeks, had undergone an upper endoscopy, and scored at least 8 points on the GerdQ [6]. Qualitative data guided development of 26 draft items. Items were reviewed by expert panels and debriefed with patients. The resulting 21-item instrument underwent psychometric evaluation during a Phase IIB trial. RESULTS During the trial, confirmatory factor analysis (n = 220) resulted in a four-factor model displaying the highest goodness of fit. All domains had a high inter-item correlation (Cronbach's α > 0.8). Test-retest reliability and convergent validity were strong, with highly significant (p < 0.01) correlations between average weekly PRISM scores and severity anchors and significant (p < 0.05) correlations with anchor subscales. Cumulative distribution functions revealed significant differences between responders and non-responders. CONCLUSIONS Analysis in a clinical trial setting demonstrated strong psychometric properties suggesting validity of PRISM. Developed in line with FDA guidance on PROs, PRISM represents an important new outcome measure for patients with GERD with a partial response to PPI therapy.
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Affiliation(s)
- Garth Fuller
- Cedars-Sinai Center for Outcomes Research and Education (CS-CORE), 116 N. Robertson Blvd.Suite 400, Los Angeles, CA, 90048, USA
| | - Roger Bolus
- Cedars-Sinai Center for Outcomes Research and Education (CS-CORE), 116 N. Robertson Blvd.Suite 400, Los Angeles, CA, 90048, USA.,UCLA Fielding School of Public Health, Los Angeles, CA, USA.,, 1016 Quail Gardens Ct, Encinitas, CA, 92024, USA
| | - Cynthia Whitman
- Cedars-Sinai Center for Outcomes Research and Education (CS-CORE), 116 N. Robertson Blvd.Suite 400, Los Angeles, CA, 90048, USA.,, 44 16th Street, Hermosa Beach, CA, 90254, USA
| | - Jennifer Talley
- Cedars-Sinai Center for Outcomes Research and Education (CS-CORE), 116 N. Robertson Blvd.Suite 400, Los Angeles, CA, 90048, USA
| | - M Haim Erder
- M. H. Erder Health Economics, Inc, Livingston, NJ, USA
| | | | | | - Brennan Spiegel
- Cedars-Sinai Center for Outcomes Research and Education (CS-CORE), 116 N. Robertson Blvd.Suite 400, Los Angeles, CA, 90048, USA. .,UCLA Fielding School of Public Health, Los Angeles, CA, USA. .,Department of Medicine, Cedars-Sinai Health System, Cedars-Sinai Medical Center, Los Angeles, CA, USA. .,VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA.
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Miner PB, Silberg DG, Ruth M, Miller F, Pandolfino J. Dose-dependent effects of lesogaberan on reflux measures in patients with refractory gastroesophageal reflux disease: a randomized, placebo-controlled study. BMC Gastroenterol 2014; 14:188. [PMID: 25407279 PMCID: PMC4289246 DOI: 10.1186/1471-230x-14-188] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Accepted: 05/29/2014] [Indexed: 01/09/2023] Open
Abstract
Background The γ-aminobutyric acid type B-receptor agonist lesogaberan (AZD3355) has been developed for use in patients with gastroesophageal reflux disease (GERD) symptoms despite proton pump inhibitor (PPI) therapy (partial responders). This study aimed to explore the dose–response effect of lesogaberan on reflux episodes in partial responders. Methods In this randomized, single-centre, double-blind, crossover, placebo-controlled study, partial responders taking optimised PPI therapy were given 30, 90, 120 and 240 mg doses of lesogaberan. Each dose was given twice (12 h apart) during a 24-h period, during which impedance–pH measurements were taken. Results Twenty-five patients were included in the efficacy analysis and 27 in the safety analysis. The effect of lesogaberan on the mean number of reflux episodes was dose-dependent, and all doses significantly reduced the mean number of reflux episodes relative to placebo. Lesogaberan also dose-dependently reduced the mean number of acid reflux episodes (except the 30 mg dose) and weakly acid reflux episodes (all doses) significantly, relative to placebo. Regardless of dose, lesogaberan had a similar effect on the percentage of time with esophageal pH < 4 [mean reduction: 68.5% (30 mg), 54.2% (90 mg), 65.9% (120 mg), 72.1% (240 mg); p < 0.05 except 90 mg dose]. No adverse events led to discontinuation and no serious adverse events occurred during active treatment. Conclusions Lesogaberan inhibited reflux in a dose-dependent manner in partial responders taking optimised PPI therapy, and these effects were significant versus placebo. All lesogaberan doses were well tolerated and were not associated with clinically relevant adverse events. Trial registration ClinicalTrials.gov identifier:
NCT01043185.
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Affiliation(s)
- Philip B Miner
- Oklahoma Foundation for Digestive Research, 535 NW 9th Street, Suite 325, Oklahoma City, OK, USA.
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Abstract
OBJECTIVE Lesogaberan (AZD3355) is a novel γ-aminobutyric acid B-type receptor agonist designed to treat gastro-oesophageal reflux disease (GERD) by inhibiting transient lower oesophageal sphincter relaxations. A randomised, double-blind, placebo-controlled, multi-centre phase IIb study was performed to assess the efficacy and safety of lesogaberan as an add-on to proton pump inhibitor (PPI) therapy in patients with GERD who are partially responsive to PPI therapy (ClinicalTrials.gov reference: NCT01005251). DESIGN In total, 661 patients were randomised to receive 4 weeks of placebo or 60, 120, 180 or 240 mg of lesogaberan twice daily, in addition to ongoing PPI therapy. Symptoms were measured using the Reflux Symptom Questionnaire electronic Diary. Response to treatment was defined as having an average of ≥ 3 additional days per week of not more than mild GERD symptoms during treatment compared with baseline. RESULTS In the primary analysis, 20.9%, 25.6%, 23.5% and 26.2% of patients responded to the 60, 120, 180 and 240 mg twice daily lesogaberan doses, respectively, and 17.9% responded to placebo. The response to the 240 mg twice daily dose was statistically significantly greater than the response to placebo using a one-sided test at the predefined significance level of p < 0.1. However, the absolute increases in the proportions of patients who responded to lesogaberan compared with placebo were low. Lesogaberan was generally well tolerated, although six patients receiving lesogaberan developed reversible elevated alanine transaminase levels. CONCLUSIONS In patients with GERD symptoms partially responsive to PPI therapy, lesogaberan was only marginally superior to placebo in achieving an improvement in symptoms.
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Affiliation(s)
- Nicholas J Shaheen
- Center for Esophageal Diseases and Swallowing, Department of Medicine, School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
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Abstract
PURPOSE The goal of this retrospective analysis was to assess how well predictive models could determine which patients would develop liver chemistry signals during clinical trials based on their pretreatment (baseline) information. PATIENTS AND METHODS Based on data from 24 late-stage clinical trials, classification models were developed to predict liver chemistry outcomes using baseline information, which included demographics, medical history, concomitant medications, and baseline laboratory results. RESULTS Predictive models using baseline data predicted which patients would develop liver signals during the trials with average validation accuracy around 80%. Baseline levels of individual liver chemistry tests were most important for predicting their own elevations during the trials. High bilirubin levels at baseline were not uncommon and were associated with a high risk of developing biochemical Hy's law cases. Baseline γ-glutamyltransferase (GGT) level appeared to have some predictive value, but did not increase predictability beyond using established liver chemistry tests. CONCLUSION It is possible to predict which patients are at a higher risk of developing liver chemistry signals using pretreatment (baseline) data. Derived knowledge from such predictions may allow proactive and targeted risk management, and the type of analysis described here could help determine whether new biomarkers offer improved performance over established ones.
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Affiliation(s)
- Zhaohui Cai
- AstraZeneca Pharmaceuticals, Wilmington, DE, USA.
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Niazi M, Silberg DG, Miller F, Ruth M, Holmberg AA. Evaluation of the pharmacokinetic interaction between lesogaberan (AZD3355) and esomeprazole in healthy subjects. Drugs R D 2011; 10:243-51. [PMID: 21171670 PMCID: PMC3586101 DOI: 10.2165/11588180-000000000-00000] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Background: Transient lower esophageal sphincter relaxations (TLESRs) have been identified as a primary cause of reflux events in patients with gastroesophageal reflux disease (GERD). GABAB receptor agonists such as lesogaberan (AZD3355) have been shown to inhibit TLESRs in healthy subjects and patients with GERD, and, therefore, offer a novel therapeutic add-on strategy to acid suppression for the management of GERD. As lesogaberan is being developed as an add-on treatment for the management of patients with GERD who have a partial response to proton pump inhibitor (PPI) therapy, it is important to rule out any clinically important pharmacokinetic drug-drug interaction between lesogaberan and PPIs. Objective: To evaluate the effect of esomeprazole on the pharmacokinetics and safety of lesogaberan and vice versa. Study Design: This was an open-label, randomized, three-way crossover study. The study was open to healthy adult male and female subjects. The study subjects received treatment with, in random order, lesogaberan (150mg twice daily [dose interval 12 hours]), esomeprazole (40 mg once daily), and a combination of both, during 7-day treatment periods. Main Outcome: The presence or absence of pharmacokinetic interactions between lesogaberan and esomeprazole was assessed by measuring the steady-state area under the plasma concentration-time curves during the dosing interval (AUCτ) and the maximum observed plasma concentration (Cmax) for lesogaberan and esomeprazole. Results: Thirty male subjects (mean age 23.2 years, 97% Caucasian) were randomized to treatment and 28 subjects completed the study (one subject was lost to follow-up, and one subject discontinued due to an adverse event). The 95% confidence intervals of the geometric mean ratios for AUCτ and Cmax of lesogaberan and esomeprazole administered alone and concomitantly were within the recognized boundaries of bioequivalence (0.8–1.25). No new safety concerns were raised during this study. The number of patients with adverse events during treatment with lesogaberan alone (n = 17) and concomitantly with esomeprazole (n = 18) were comparable but higher than with esomeprazole alone (n = 10). Paresthesia (episodic, mild, and transient), pharyngitis, and flatulence were the most frequently reported adverse events. Conclusions: There was no observed pharmacokinetic interaction between lesogaberan and esomeprazole when concomitantly administered to healthy subjects, and concomitant therapy was well tolerated. Trial registration number (clinicaltrials.gov): NCT00684190
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Boeckxstaens GE, Beaumont H, Hatlebakk JG, Silberg DG, Björck K, Karlsson M, Denison H. A novel reflux inhibitor lesogaberan (AZD3355) as add-on treatment in patients with GORD with persistent reflux symptoms despite proton pump inhibitor therapy: a randomised placebo-controlled trial. Gut 2011; 60:1182-8. [PMID: 21402616 DOI: 10.1136/gut.2010.235630] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE o evaluate the efficacy and tolerability of add-on treatment with lesogaberan (AZD3355), a novel reflux inhibitor, in patients with persistent gastro-oesophageal reflux disease (GORD) symptoms despite proton pump inhibitor (PPI) therapy. METHODS double-blind, placebo-controlled, randomised, parallel-group, multicentre phase IIA study was carried out in outpatient clinics. The study group comprised 244 adult patients with persistent GORD symptoms (heartburn and/or regurgitation) of at least mild intensity and for 3 days of 7 days before enrolment, despite ≥6 weeks of continuous PPI therapy. Patients received either lesogaberan (65 mg twice daily) or placebo in addition to PPI therapy for a period of 4 weeks. Symptom intensity, based on the Reflux Disease Questionnaire, was recorded twice daily. Treatment response (defined as at most one 24 h period with heartburn or regurgitation of not more than mild intensity during the last 7 days of treatment). Time to response, proportion of symptom-free days and measures of tolerability were also analysed. RESULTS total of 232 (114 lesogaberan- and 118 placebo-treated patients) of the 244 randomised patients were analysed for efficacy. Treatment with lesogaberan, compared with placebo, resulted in a significantly larger proportion of responders to treatment (16% vs 8% of patients; p=0.026) and cumulative proportion of responders over time (log-rank p=0.0195). Lesogaberan was well tolerated: adverse events of mostly mild to moderate intensity were reported in 45% of patients on lesogaberan and in 37% on placebo. CONCLUSIONS esogaberan add-on therapy to PPIs significantly improved heartburn and regurgitation symptoms; however, the proportion of responders was small. Clinical trial number NCT00394472.
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Affiliation(s)
- Guy E Boeckxstaens
- Department of Gastroenterology, University Hospital Leuven, Catholic University of Leuven, Herestraat 49, 3000 Leuven, Belgium.
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Boeckxstaens GE, Beaumont H, Mertens V, Denison H, Ruth M, Adler J, Silberg DG, Sifrim D. Effects of lesogaberan on reflux and lower esophageal sphincter function in patients with gastroesophageal reflux disease. Gastroenterology 2010; 139:409-17. [PMID: 20451523 DOI: 10.1053/j.gastro.2010.04.051] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Revised: 04/15/2010] [Accepted: 04/29/2010] [Indexed: 01/03/2023]
Abstract
BACKGROUND & AIMS Transient lower esophageal sphincter relaxations (TLESRs) are a major mechanism behind reflux. This study assessed the effects of lesogaberan (AZD3355), a novel gamma-aminobutyric acid type B receptor agonist, on reflux and lower esophageal sphincter (LES) function when used as add-on treatment in patients with reflux symptoms despite proton pump inhibitor (PPI) treatment. METHODS In this randomized, double-blind, placebo-controlled, crossover study, patients received lesogaberan (65 mg) or placebo twice on day 1 (morning/evening) and once on day 2 (morning), in addition to existing PPI treatment. Patients consumed a standardized meal 45-60 minutes after morning doses. Ambulatory impedance-pH monitoring was conducted for 24 hours after the first dose on day 1. Stationary manometry and impedance-pH monitoring was conducted for 4 hours after the third dose on day 2. RESULTS Of 27 randomized patients, 21 were included in the per-protocol efficacy analysis. During the 24 hours after treatment start, lesogaberan reduced the mean number of reflux events by approximately 35% compared with placebo. During the 3 postprandial hours on day 2, lesogaberan reduced the geometric mean number of TLESRs by 25% and increased geometric mean LES pressure by 28% compared with placebo. The most common adverse events were headache (placebo: 11/27 patients; lesogaberan: 8/25 patients) and paresthesia (transient; placebo: 3/27 patients; lesogaberan: 5/25 patients). CONCLUSIONS In patients with reflux symptoms despite PPI treatment, lesogaberan decreased the number of TLESRs and reflux episodes, and increased LES pressure compared with placebo. These findings support further evaluation of lesogaberan as an add-on treatment in patients partially responding to PPIs.
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Abstract
OBJECTIVES The primary objective was to assess gastroesophageal reflux disease (GERD) symptom resolution rates with esomeprazole by erosive esophagitis (EE) status, and the secondary objective was to evaluate potential predictors of the presence of EE and heartburn resolution. BACKGROUND Patients with GERD who have EE have higher reported symptom resolution rates than those with nonerosive reflux disease (NERD) when treated with proton pump inhibitors (PPIs). STUDY This open-label multicenter study included adults with GERD symptoms. Patients were stratified by EE status after endoscopy and received once-daily esomeprazole 40 mg for 4 weeks. Questionnaires determined symptom response rates, and baseline predictors of EE or heartburn resolution were evaluated. Potential predictors, including years with GERD, history of EE, and time to relief with antacids, were examined. RESULTS Heartburn resolution rates at 4 weeks were higher for patients with EE than NERD (69% [124/179] vs. 48% [85/177]; p < 0.0001). Multivariate models had moderate predictive ability for EE (c-index, 0.76) and poor predictive ability (c-index, 0.57) for heartburn resolution. However, faster heartburn relief with antacid use, particularly within 15 min, was predictive of EE and heartburn resolution. CONCLUSIONS Patients with EE have higher heartburn resolution rates than patients with NERD after treatment, although recall bias may be possible. Fast relief with antacid use is predictive of EE and heartburn resolution with a PPI and suggests that a history of antacid relief may provide corroborative evidence to empiric PPI therapy in determining whether patients with heartburn have acid reflux disease. ClinicalTrials.Gov IDENTIFIER: NCT00242736.
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Affiliation(s)
- Roy C Orlando
- University of North Carolina Division of Gastroenterology & Hepatology, Chapel Hill, NC 27599-7032, USA.
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14
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Spechler SJ, Barker PN, Silberg DG. Clinical trial: intragastric acid control in patients who have Barrett's oesophagus--comparison of once- and twice-daily regimens of esomeprazole and lansoprazole. Aliment Pharmacol Ther 2009; 30:138-45. [PMID: 19438416 DOI: 10.1111/j.1365-2036.2009.04032.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
BACKGROUND Gastric acid control is important for treatment of gastro-oesophageal reflux disease associated with Barrett's oesophagus. Substantial indirect evidence suggests that gastric acid control may have a chemopreventive role in Barrett's oesophagus. AIM To compare the pharmacodynamic efficacy of esomeprazole and lansoprazole at two dosages for intragastric pH control with Barrett's oesophagus. METHODS Patients with Barrett's oesophagus received open-label consecutive treatment (a 15-day period of once-daily dosing followed by a 10-day period of twice-daily dosing) with esomeprazole (40-mg capsules) and lansoprazole (30-mg capsules) in random order with no washouts. Twenty-four-hour intragastric pH was recorded on the last day of each dosing period. The primary end point was the percentage of time with intragastric pH > 4.0. RESULTS In the per-protocol once- (n = 46) and twice-daily (n = 41) analyses, the percentage of time with intragastric pH > 4.0 was significantly (P < 0.0001) longer after once- (67.1%) or twice-daily (81.2%) esomeprazole than after once- (50.8%) or twice-daily (64.3%) lansoprazole. The proportion of patients with intragastric pH > 4.0 for >12 h was significantly higher for esomeprazole than lansoprazole with once- (P = 0.004) and twice-daily (P = 0.016) dosing. CONCLUSION Esomeprazole 40 mg is significantly more effective than lansoprazole 30 mg in controlling intragastric pH with Barrett's oesophagus.
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Affiliation(s)
- S J Spechler
- VA North Texas Healthcare System and the University of Texas Southwestern Medical Center, Dallas, TX 75216, USA.
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15
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Kong J, Nakagawa H, Isariyawongse BK, Funakoshi S, Silberg DG, Rustgi AK, Lynch JP. Induction of intestinalization in human esophageal keratinocytes is a multistep process. Carcinogenesis 2009; 30:122-30. [PMID: 18845559 PMCID: PMC2722140 DOI: 10.1093/carcin/bgn227] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2008] [Revised: 08/28/2008] [Accepted: 09/24/2008] [Indexed: 12/22/2022] Open
Abstract
Barrett's esophagus (BE) is the replacement of normal squamous esophageal mucosa with an intestinalized columnar epithelium. The molecular mechanisms underlying its development are not understood. Cdx2 is an intestine-specific transcription factor that is ectopically expressed in BE, but its role in this process is unclear. Herein, we describe a novel cell culture model for BE. Retroviral-mediated Cdx2 expression in immortalized human esophageal keratinocytes [EPC-human telomerase reverse transcriptase (hTERT)] could transiently be established but not maintained and was associated with a reduction in cell proliferation. Coexpression of cyclin D1, but not a dominant-negative p53, rescued proliferation in the Cdx2-expressing cells. Cdx2 expression in the EPC-hTERT.D1 cells decreased cell proliferation but did not induce intestinalization. We investigated for other treatments to enhance intestinalization and found that acidic culture conditions uniformly killed EPC-hTERT.D1.Cdx2 cells. However, treatment with 5-aza-2-deoxycytidine (5-AzaC) to demethylate epigenetically silenced genes did appear to be tolerated. Multiple Cdx2 target genes, markers of intestinal differentiation and markers of BE, were induced by this 5-AzaC treatment. More interestingly, the expression level of several of these genes was enhanced only in the EPC-hTERT.D1-Cdx2 cells treated with 5-AzaC. Two of these, SLC26a3/DRA (downregulated in adenoma) and Na+/H+ exchanger 2 (NHE2), were not previously known to be elevated in BE; however, we confirmed their elevation in BE tissue samples. 5-AzaC treatment also induced cell senescence, even at low doses. We conclude that ectopic proliferation signals, alterations in epigenetic gene regulation and the inhibition of tumor suppressor mechanisms are required for Cdx2-mediated intestinalization of human esophageal keratinocytes in BE.
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Affiliation(s)
- Jianping Kong
- Department of Medicine, Division of Gastroenterology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hiroshi Nakagawa
- Department of Medicine, Division of Gastroenterology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Brandon K. Isariyawongse
- Department of Medicine, Division of Gastroenterology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Shinsuke Funakoshi
- Department of Medicine, Division of Gastroenterology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Debra G. Silberg
- Department of Medicine, Division of Gastroenterology, University of Pennsylvania, Philadelphia, PA 19104, USA
- AstraZeneca LP, Wilmington, DE 19850-5437, USA
| | - Anil K. Rustgi
- Department of Medicine, Division of Gastroenterology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - John P. Lynch
- Department of Medicine, Division of Gastroenterology, University of Pennsylvania, Philadelphia, PA 19104, USA
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Stairs DB, Nakagawa H, Klein-Szanto A, Mitchell SD, Silberg DG, Tobias JW, Lynch JP, Rustgi AK. Cdx1 and c-Myc foster the initiation of transdifferentiation of the normal esophageal squamous epithelium toward Barrett's esophagus. PLoS One 2008; 3:e3534. [PMID: 18953412 PMCID: PMC2568822 DOI: 10.1371/journal.pone.0003534] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2008] [Accepted: 09/28/2008] [Indexed: 01/16/2023] Open
Abstract
Background Barrett's esophagus is a premalignant condition whereby the normal stratified squamous esophageal epithelium undergoes a transdifferentiation program resulting in a simple columnar epithelium reminiscent of the small intestine. These changes are typically associated with the stratified squamous epithelium chronically exposed to acid and bile salts as a result of gastroesophageal reflux disease (GERD). Despite this well-defined epidemiologic association between acid reflux and Barrett's esophagus, the genetic changes that induce this transdifferentiation process in esophageal keratinocytes have remained undefined. Methodology/Principal Findings To begin to identify the genetic changes responsible for transdifferentiaiton in Barrett's esophagus, we performed a microarray analysis of normal esophageal, Barrett's esophagus and small intestinal biopsy specimens to identify candidate signaling pathways and transcription factors that may be involved. Through this screen we identified the Cdx1 homeodomain transcription factor and the c-myc pathway as possible candidates. Cdx1 and c-myc were then tested for their ability to induce transdifferentiation in immortalized human esophageal keratinocytes using organotypic culturing methods. Analyses of these cultures reveal that c-myc and cdx1 cooperate to induce mucin production and changes in keratin expression that are observed in the epithelium of Barrett's esophagus. Conclusions/Significance These data demonstrate the ability of Cdx1 and c-myc to initiate the earliest stages of transdifferentiation of esophageal keratinocytes toward a cell fate characteristic of Barrett's esophagus.
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Affiliation(s)
- Douglas B Stairs
- Division of Gastroenterology, Department of Medicine, Abramson Cancer Center, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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17
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Drossman DA, Danilewitz M, Naesdal J, Hwang C, Adler J, Silberg DG. Randomized, double-blind, placebo-controlled trial of the 5-HT1A receptor antagonist AZD7371 tartrate monohydrate (robalzotan tartrate monohydrate) in patients with irritable bowel syndrome. Am J Gastroenterol 2008; 103:2562-9. [PMID: 18775020 DOI: 10.1111/j.1572-0241.2008.02115.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES To investigate the efficacy and safety of the 5-hydroxytrypamine 1A (5-HT(1A)) receptor antagonist AZD7371 tartrate monohydrate (robalzotan tartrate monohydrate), termed AZD7371 here, in patients with irritable bowel syndrome (IBS). METHODS Patients meeting the Rome II criteria for IBS (N = 402) were randomized to treatment with AZD7371 20 mg or 5 mg or matching placebo tablets twice daily for 12 wk. The patients completed daily and weekly diary assessments, reporting abdominal discomfort or pain and description of bowel movements. They also completed validated symptom and quality-of-life questionnaires. RESULTS Neither AZD7371 regimen was significantly more effective than placebo in providing adequate relief from IBS symptoms in at least 2 out of 4 wk per month over the 12 wk of treatment. There was also no significant difference between the treatment groups and placebo in the change in score in the validated symptom and quality-of-life questionnaires. Overall, 22.1% of patients experienced adverse events (AEs) attributed to the study medication: 44 of 133 (33.1%) in the 20 mg AZD7371 group, 27 of 131 (20.6%) in the 5 mg AZD7371 group, and 17 of 134 (12.7%) in the placebo group. Also, 31 of 57 (54%) of AEs leading to discontinuation were central nervous system-related. Hallucinations or hallucination-like AEs were reported by eight patients taking AZD7371, and by none of the patients in the placebo group. After these events led to discontinuation in six patients, the study was prematurely terminated. CONCLUSIONS In view of the AE profile and lack of efficacy in IBS, the clinical development of AZD7371 has been stopped.
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Affiliation(s)
- Douglas A Drossman
- Division of Gastroenterology and Hepatology, University of North Carolina Center for Functional GI and Motility Disorders, Chapel Hill, North Carolina 27599-7080, USA
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18
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Katz PO, Ginsberg GG, Hoyle PE, Sostek MB, Monyak JT, Silberg DG. Relationship between intragastric acid control and healing status in the treatment of moderate to severe erosive oesophagitis. Aliment Pharmacol Ther 2007; 25:617-28. [PMID: 17305763 DOI: 10.1111/j.1365-2036.2006.03235.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
AIM To assess the relationship between the percentage of time intragastric pH >4.0 and healing of erosive oesophagitis. METHODS In this proof-of-concept study, adults with endoscopically verified Los Angeles grade C or grade D erosive oesophagitis were randomly assigned to oral esomeprazole 10 or 40 mg once daily for 4 weeks. On day 5, patients underwent 24-h pH monitoring. At 4 weeks, erosive oesophagitis healing status was endoscopically assessed. Investigators scored gastro-oesophageal reflux disease symptoms on a 4-point scale [none to severe (0-3)] before and 4 weeks after treatment. The percentage of time intragastric pH was >4.0 and healing status were correlated and tested for significance using a Spearman rank correlation (r). RESULTS 103 patients had evaluable data (mean age, 48.7 years; 65% men). Mean percentages of time with intragastric pH >4.0 on day 5 in patients with healed and unhealed erosive oesophagitis were 61% and 42%, respectively (P = 0.0002), indicating that erosive oesophagitis healing rates were positively related to the percentage of time intragastric pH was >4.0. Greater intragastric acid control correlated with lower final daytime and night-time heartburn and acid regurgitation symptom scores (r = -0.029, -0.029 and -0.021; P = 0.003, 0.003 and 0.032, respectively). CONCLUSION A positive relationship between intragastric acid control and erosive oesophagitis healing was demonstrated.
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Affiliation(s)
- P O Katz
- Albert Einstein Medical Center, Philadelphia, PA 19141, USA.
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19
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Goldstein JL, Miner PB, Schlesinger PK, Liu S, Silberg DG. Intragastric acid control in non-steroidal anti-inflammatory drug users: comparison of esomeprazole, lansoprazole and pantoprazole. Aliment Pharmacol Ther 2006; 23:1189-96. [PMID: 16611280 DOI: 10.1111/j.1365-2036.2006.02867.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Studies to date have not directly compared the pharmacodynamic efficacies of different proton pump inhibitors in controlling intragastric acidity in patients treated with non-steroidal anti-inflammatory drugs. AIM To compare acid suppression with once-daily esomeprazole 40 mg, lansoprazole 30 mg and pantoprazole 40 mg in patients receiving non-selective or cyclo-oxygenase-2-selective non-steroidal anti-inflammatory drug therapy. METHODS In this multicentre, open-label, comparative, three-way crossover study, adult patients (n = 90) receiving non-steroidal anti-inflammatory drugs were randomized to one of six treatment sequences. At the study site, patients were administered esomeprazole 40 mg, lansoprazole 30 mg and pantoprazole 40 mg for 5 days each, with a washout period of > or =10 days between each treatment. Twenty-four-hour pH testing was performed on day 5 of each dosing period. RESULTS The mean percentage of time during the 24-h pH monitoring period that gastric pH was >4.0 was significantly greater with esomeprazole (74.2%) compared with lansoprazole (66.5%; P < 0.001) and pantoprazole (60.8%; P < 0.001), and significantly greater with esomeprazole (P < 0.05) than with the comparators regardless of whether using non-selective vs. cyclo-oxygenase-2-selective non-steroidal anti-inflammatory drugs. CONCLUSIONS At the doses studied, esomeprazole treatment provides significantly greater gastric acid suppression than lansoprazole or pantoprazole in patients receiving non-selective or cyclo-oxygenase-2-selective non-steroidal anti-inflammatory drugs.
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Affiliation(s)
- J L Goldstein
- Department of Medicine, Section of Digestive Diseases and Nutrition, University of Illinois at Chicago, IL 60612, USA.
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20
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Xiao F, Crissey MAS, Lynch JP, Kaestner KH, Silberg DG, Suh E. Intestinal metaplasia with a high salt diet induces epithelial proliferation and alters cell composition in the gastric mucosa of mice. Cancer Biol Ther 2005; 4:669-75. [PMID: 15970710 DOI: 10.4161/cbt.4.6.1734] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Intestinal metaplasia of the gastric mucosa is an important component in the pathway to adenocarcinoma. The mechanisms that induce the progression from intestinal metaplasia to cancer have not been elucidated. High dietary salt has been known as one of the risk factors for gastric cancer development in humans. Therefore, we investigated the role of high salt diet on gastric epithelial cell proliferation and differentiation, using our mouse model that ectopically expressed Cdx2 homeodomain transcription factor and induced an intestinal metaplastic phenotype in the gastric epithelia. Sixty Cdx2 transgenic and sixty age-matched wild-type littermates were studied. Fifty-percent Cdx2 transgenic and wild type mice were administered a high-salt diet and the other fifty-percent was fed a standard diet starting at 12 weeks after birth. At 10, 20 and 40 weeks after initiation of the diets, histopathological changes were determined by Hemotoxylin and Eosin, alcian blue, and periodic acid-Schiff (PAS) staining. Cell types and cell kinetics were assessed by immunohistochemistry. At 52 weeks, significant alterations in pathology were observed in the Cdx2 transgenic mice fed a high-salt diet, including elongation of gastric pits, reduction of the glandular zone in the gastric corpus, and deepening of glands in the antrum. In the Cdx2 transgenic mice fed a high salt diet, the parietal and chief cells were significantly decreased in the gastric corpus. A significant increase in cell proliferation and apoptosis in the corpus and antrum were observed in Cdx2 transgenic mice fed a high-salt diet as compared to wild-type littermates. Taken together, these data implicate that intestinal metaplasia in concert with a high-salt diet induces epithelial proliferation, apoptosis, and alters cellular types in the gastric mucosa of mice. Alteration in the composition of the gastric epithelium may play a role in influencing the microenvironment to engender susceptibility to carcinogens.
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Affiliation(s)
- Fang Xiao
- Gastroenterology Division, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
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21
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Wang ML, Shin ME, Knight PA, Artis D, Silberg DG, Suh E, Wu GD. Regulation of RELM/FIZZ isoform expression by Cdx2 in response to innate and adaptive immune stimulation in the intestine. Am J Physiol Gastrointest Liver Physiol 2005; 288:G1074-83. [PMID: 15576623 DOI: 10.1152/ajpgi.00442.2004] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Host immune responses to commensal flora and enteric pathogens are known to influence gene expression in the intestinal epithelium. Although the Cdx family of caudal-related transcription factors represents critical regulators of gene expression in the intestinal epithelium, the effect of intestinal immune responses on Cdx expression and function has not been determined. We have shown that bacterial colonization and Th2 immune stimulation by intestinal nematode infection induce expression of the intestinal goblet cell-specific gene RELM beta. In this study, we investigated the transcriptional regulation of resistin-like molecule/found in inflammatory zone (RELM/FIZZ, RELM beta) and its isoforms RELM alpha and RELM gamma to ascertain the role of Cdx in modifying intestinal gene expression associated with innate and adaptive immune responses. Analysis of the RELM beta promoter showed that Cdx2 plays a critical role in basal gene activation in vitro. This was confirmed in vivo using transgenic mice, where ectopic gastric and hepatic expression of Cdx2 induces expression of RELM beta, but not RELM alpha or RELM gamma, exclusively in the stomach. Although there was no quantitative change in colonic Cdx2 mRNA expression, protein distribution, or phosphorylation of Cdx2, bacterial colonization induced expression of RELM beta, but not RELM alpha or RELM gamma. In contrast, parasitic nematode infections activated colonic expression of all three RELM isoforms without alteration in Cdx2 expression. These results demonstrated that Cdx2 participates in directing intestine-specific expression of RELM beta in the presence of commensal bacteria and that adaptive Th2 immune responses to intestinal nematode infections can activate intestinal goblet cell-specific gene expression independent of Cdx2.
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Affiliation(s)
- Mei-Lun Wang
- Division of Gastroenterology and Nutrition, The Children's Hospital of Philadelphia, Pennsylvania 19104-6144, USA
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22
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Katz JP, Perreault N, Goldstein BG, Actman L, McNally SR, Silberg DG, Furth EE, Kaestner KH. Loss of Klf4 in mice causes altered proliferation and differentiation and precancerous changes in the adult stomach. Gastroenterology 2005; 128:935-45. [PMID: 15825076 DOI: 10.1053/j.gastro.2005.02.022] [Citation(s) in RCA: 186] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND & AIMS The epithelial zinc-finger transcription factor Klf4 (formerly GKLF) regulates cellular proliferation and differentiation in vitro. Klf4 null mice die by postnatal day 1 and show changes in epithelial differentiation of skin and colon. METHODS We used tissue-specific gene ablation to generate mice lacking Klf4 in their gastric epithelia. Klf4 mutant mice and controls were killed for histology, immunohistochemistry, quantitative real-time polymerase chain reaction (qPCR), and serum gastrin levels. Klf4 messenger RNA (mRNA) levels were analyzed in Foxa3-Cdx2 transgenic mice and controls. Human gastric cancers and matched normal tissue were used for qPCR and immunohistochemistry for KLF4. RESULTS Klf4 mutant mice survive to adulthood and show increased proliferation and altered differentiation of their gastric epithelia. Klf4 mutants also display aberrant expression of acidic mucins and TFF2/SP-positive cells, findings characteristic of premalignant conditions, but no inflammation, intestinal metaplasia, dysplasia, or cancer up to 1 year of age. Expression of KLF4 is nearly absent in human gastric cancer, suggesting that failure to activate KLF4 during normal cellular differentiation may be a common feature of gastric cancers. p21 WAF1/CIP1 is an in vivo target of Klf4, but Klf4 is not a mediator of Cdx2. CONCLUSIONS Loss of a single genetic factor, Klf4, leads to dramatic changes in the gastric epithelia of mice, and Klf4 is part of a regulatory pathway involving p21 WAF1/CIP1 but not Cdx2. Thus, Klf4 is critical for normal gastric epithelial homeostasis.
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Affiliation(s)
- Jonathan P Katz
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104-6145, USA
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Rankin EB, Xu W, Silberg DG, Suh E. Putative intestine-specific enhancers located in 5' sequence of the CDX1 gene regulate CDX1 expression in the intestine. Am J Physiol Gastrointest Liver Physiol 2004; 286:G872-80. [PMID: 14715525 DOI: 10.1152/ajpgi.00326.2003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
CDX1 is a homeobox transcription factor that plays a critical role in intestinal epithelial cell growth and differentiation. CDX1 gene expression is tightly regulated in a temporal and cell-type specific manner. However, very little is known about the regulatory mechanisms that direct CDX1 gene expression in the intestine. To elucidate these mechanisms, we employed a series of transgenic mouse studies using the 5' flanking sequences of the human CDX1 gene. Transgenic mice containing nucleotides between -5667 and +68 relative to the transcription start site of the CDX1 gene demonstrated ectopic expression of the transgene in the brain and gastric smooth muscle. However, transgenic expression of the nucleotides -15601 to +68 of the CDX1 gene was restricted to the intestinal epithelium, which was identical to endogenous CDX1 gene expression. Taken together, the upstream sequences between -15601 and -5667 contain regulatory elements that direct transgene expression specifically to the intestinal epithelium. Furthermore, DNase I hypersensitivity assays revealed two active chromatin regions in the CDX1 gene (hypertensive sites 1 and 2) located at approximately -5.8 and -6.8 kb upstream of the CDX1 gene, respectively, which may function as potential intestine-specific enhancers.
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Affiliation(s)
- Erinn B Rankin
- Gastroenterology Div., Dept. of Medicine, Univ. of Pennsylvania, Ste. 600, 415 Curie Blvd., Philadelphia, PA 19104, USA
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Brembeck FH, Schreiber FS, Deramaudt TB, Craig L, Rhoades B, Swain G, Grippo P, Stoffers DA, Silberg DG, Rustgi AK. The mutant K-ras oncogene causes pancreatic periductal lymphocytic infiltration and gastric mucous neck cell hyperplasia in transgenic mice. Cancer Res 2003; 63:2005-9. [PMID: 12727809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
A frequent genetic alteration found in premalignant stages of pancreatic adenocarcinoma is K-ras oncogene point mutation. The mechanistic basis for the inability of K-ras mutation to transform pancreatic ductal cells is unclear, although cooperating events with p16 inactivation, p53 mutation, and SMAD 4 mutation are recognized to be necessary. We have generated a novel mouse model in which the cytokeratin 19 promoter, specifically active in pancreatic ductal cells but not other cell types of the pancreas, is fused to mutant K-ras. This is of direct relevance to human pancreatic cancer because premalignant lesions are found specifically in ductal cells. There is dramatic periductal lymphocytic infiltration in the pancreata of transgenic mice, predominantly CD4+ T lymphocytes, which may act as an adaptive immune response to activated ras-mediated signaling. In addition, gene array analysis reveals an induction of N-cadherin in transgenic mice pancreatic ductal cells, the significance of which relates to promotion of cell adhesion and deterrence of cell migration. Apart from these important biological considerations, there is parallel activity of the cytokeratin 19 promoter in the stem cell region of the gastric epithelium, namely in mucous neck cells. Activated K-ras in this context causes mucous neck cell hyperplasia, a precursor to gastric adenocarcinoma. There is concomitant parietal cell decrease, which is a key step toward gastric adenocarcinoma. Taken together, we have defined how mutant K-ras signaling modulates important molecular events in the initiating events of pancreatic and gastric carcinogenesis.
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Affiliation(s)
- Felix H Brembeck
- Gastrointestinal Unit, Abramson Cancer Center and Family Cancer Research Institute, University of Pennsylvania, Philadelphia 19014, USA
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Almeida R, Silva E, Santos-Silva F, Silberg DG, Wang J, De Bolós C, David L. Expression of intestine-specific transcription factors, CDX1 and CDX2, in intestinal metaplasia and gastric carcinomas. J Pathol 2003; 199:36-40. [PMID: 12474224 DOI: 10.1002/path.1246] [Citation(s) in RCA: 212] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Intestinal metaplasia (IM) is part of a stepwise sequence of alterations of the gastric mucosa, leading ultimately to gastric cancer, and is strongly associated with chronic Helicobacter pylori infection. The molecular mechanisms underlying the onset of IM remain elusive. The aim of this study was to assess the putative involvement of two intestine-specific transcription factors, CDX1 and CDX2, in the pathogenesis of gastric IM and gastric carcinoma. Eighteen foci of IM and 46 cases of gastric carcinoma were evaluated by immunohistochemistry for CDX1 and CDX2 expression. CDX1 was expressed in all foci of IM and in 41% of gastric carcinomas; CDX2 was expressed in 17/18 foci of IM and in 54% of gastric carcinomas. In gastric carcinomas, a strong association was observed between the expression of CDX1 and CDX2, as well as between the intestinal mucin MUC2 and CDX1 and CDX2. No association was observed between the expression of CDX1 and CDX2 and the histological type of gastric carcinoma. In conclusion, these results show that aberrant expression of CDX1 and CDX2 is consistently observed in IM and in a subset of gastric carcinomas. The association of CDX1 and CDX2 with expression of the intestinal mucin MUC2, both in IM and in gastric carcinoma, indirectly implies that CDX1 and CDX2 may be involved in intestinal differentiation along the gastric carcinogenesis pathway.
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Affiliation(s)
- Raquel Almeida
- Institute of Molecular Pathology and Immunology, University of Porto (IPATIMUP), 4200 Porto, Portugal.
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Boudreau F, Rings EHHM, Swain GP, Sinclair AM, Suh ER, Silberg DG, Scheuermann RH, Traber PG. A novel colonic repressor element regulates intestinal gene expression by interacting with Cux/CDP. Mol Cell Biol 2002; 22:5467-78. [PMID: 12101240 PMCID: PMC133930 DOI: 10.1128/mcb.22.15.5467-5478.2002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2002] [Revised: 03/11/2002] [Accepted: 04/24/2002] [Indexed: 01/19/2023] Open
Abstract
Intestinal gene regulation involves mechanisms that direct temporal expression along the vertical and horizontal axes of the alimentary tract. Sucrase-isomaltase (SI), the product of an enterocyte-specific gene, exhibits a complex pattern of expression. Generation of transgenic mice with a mutated SI transgene showed involvement of an overlapping CDP (CCAAT displacement protein)-GATA element in colonic repression of SI throughout postnatal intestinal development. We define this element as CRESIP (colon-repressive element of the SI promoter). Cux/CDP interacts with SI and represses SI promoter activity in a CRESIP-dependent manner. Cux/CDP homozygous mutant mice displayed increased expression of SI mRNA during early postnatal development. Our results demonstrate that an intestinal gene can be repressed in the distal gut and identify Cux/CDP as a regulator of this repression during development.
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MESH Headings
- Aging/metabolism
- Animals
- COS Cells
- Caco-2 Cells
- Colon/cytology
- Colon/growth & development
- Colon/metabolism
- DNA-Binding Proteins/metabolism
- GATA4 Transcription Factor
- Gene Expression Regulation, Developmental/physiology
- Homeodomain Proteins
- Humans
- In Situ Hybridization
- Intestinal Mucosa/metabolism
- Intestine, Small/cytology
- Intestine, Small/growth & development
- Intestine, Small/metabolism
- Intestines/cytology
- Intestines/growth & development
- Mice
- Mice, Knockout
- Mice, Transgenic
- Mutagenesis, Site-Directed
- Nuclear Proteins/metabolism
- Promoter Regions, Genetic/physiology
- RNA, Messenger/metabolism
- Regulatory Sequences, Nucleic Acid/physiology
- Repressor Proteins/metabolism
- Sucrase-Isomaltase Complex/biosynthesis
- Sucrase-Isomaltase Complex/genetics
- Transcription Factors/metabolism
- Transgenes
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Affiliation(s)
- François Boudreau
- Division of Gastroenterology, Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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Silberg DG, Sullivan J, Kang E, Swain GP, Moffett J, Sund NJ, Sackett SD, Kaestner KH. Cdx2 ectopic expression induces gastric intestinal metaplasia in transgenic mice. Gastroenterology 2002; 122:689-96. [PMID: 11875002 DOI: 10.1053/gast.2002.31902] [Citation(s) in RCA: 336] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND & AIMS Intestinal-type gastric cancer is often preceded by intestinal metaplasia in humans. The genetic events responsible for the transdifferentiation that occurs in intestinal metaplasia are not well understood. Cdx2, a transcription factor whose expression is normally limited to the intestine, has been detected in gastric intestinal metaplasia. Cdx2 induces differentiation of intestinal epithelial cells in vitro; therefore, we sought to establish whether a causal relationship exists between Cdx2 activation and intestinal metaplasia. METHODS Cdx2 expression was directed to the gastric mucosa in transgenic mice using cis-regulatory elements of Foxa3 (Hnf3gamma). Transgenic mice were analyzed for histologic and gene expression changes. RESULTS Histologic examination of the gastric mucosa of the Foxa3/Cdx2 mice revealed the presence of alcian blue-positive intestinal-type goblet cells, a hallmark of intestinal metaplasia. In addition, Cdx2 induced the expression of intestine-specific genes. CONCLUSIONS Gastric expression of Cdx2 alone was sufficient to induce intestinal metaplasia in mice. These mice represent a powerful tool to investigate the molecular mechanisms that promote intestinal metaplasia. Moreover, as gastric cancer in humans is often preceded by intestinal metaplasia, the phenotype described here strongly suggests involvement of Cdx2 in the initiation of the process leading to intestinal neoplasia of the gastric mucosa.
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Affiliation(s)
- Debra G Silberg
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.
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Steppan CM, Brown EJ, Wright CM, Bhat S, Banerjee RR, Dai CY, Enders GH, Silberg DG, Wen X, Wu GD, Lazar MA. A family of tissue-specific resistin-like molecules. Proc Natl Acad Sci U S A 2001; 98:502-6. [PMID: 11209052 PMCID: PMC14616 DOI: 10.1073/pnas.98.2.502] [Citation(s) in RCA: 456] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We have identified a family of resistin-like molecules (RELMs) in rodents and humans. Resistin is a hormone produced by fat cells. RELMalpha is a secreted protein that has a restricted tissue distribution with highest levels in adipose tissue. Another family member, RELMbeta, is a secreted protein expressed only in the gastrointestinal tract, particularly the colon, in both mouse and human. RELMbeta gene expression is highest in proliferative epithelial cells and is markedly increased in tumors, suggesting a role in intestinal proliferation. Resistin and the RELMs share a cysteine composition and other signature features. Thus, the RELMs together with resistin comprise a class of tissue-specific signaling molecules.
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Affiliation(s)
- C M Steppan
- Division of Endocrinology, Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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Abstract
BACKGROUND & AIMS The intestine-specific transcription factors Cdx1 and Cdx2 are candidate genes for directing intestinal development, differentiation, and maintenance of the intestinal phenotype. This study focused on the complex patterns of expression of Cdx1 and Cdx2 during mouse gastrointestinal development. METHODS Embryonic and postnatal mouse tissues were analyzed by immunohistochemistry to determine protein expression of Cdx1 and Cdx2 in the developing intestinal tract. RESULTS Cdx2 protein expression was observed at 9. 5 postcoitum (pc), whereas weak expression of Cdx1 protein was first seen at 12.5 pc in the distal developing intestine (hindgut). Expression of Cdx1 increased from 13.5 to 14.5 pc during the endoderm/epithelial transition with predominately distal expression. In contrast to Cdx1, there was intense expression of Cdx2 in all but the distal portions of the developing intestine. Cdx2 expression remained low in the distal colon throughout postnatal development. A gradient of expression formed in the crypt-villus axis, with Cdx1 primarily in the crypt and Cdx2 primarily in the villus. CONCLUSIONS Direct comparison of the patterns of Cdx1 and Cdx2 protein expression during development as performed in this study provides new insights into their potential functional roles. The relative expression of Cdx1 to Cdx2 protein may be important in the anterior to posterior patterning of the intestinal epithelium and in defining patterns of proliferation and differentiation along the crypt-villus axis.
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Affiliation(s)
- D G Silberg
- Division of Gastroenterology, Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
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Lynch J, Suh ER, Silberg DG, Rulyak S, Blanchard N, Traber PG. The caudal-related homeodomain protein Cdx1 inhibits proliferation of intestinal epithelial cells by down-regulation of D-type cyclins. J Biol Chem 2000; 275:4499-506. [PMID: 10660624 DOI: 10.1074/jbc.275.6.4499] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cdx1 is a homeodomain transcription factor that regulates intestine-specific gene expression. Experimental evidence suggests that Cdx1 may be involved in cell cycle regulation, but its role is ill defined and the mechanisms have not been explored. We used stable transfection of inducible constructs and transient expression with a replication-deficient adenovirus to induce Cdx1 expression in rat IEC6 cells, a non-transformed intestinal epithelial cell line that does not express Cdx1 protein. Expression of Cdx1 markedly reduced proliferation of IEC6 cells with accumulation of cells in the G(0)/G(1) phase of the cell cycle. Cell cycle arrest was accompanied by an increase in the hypophosphorylated forms of the retinoblastoma protein (pRb) and the pRb-related p130 protein. Protein levels of multiple cyclin-dependent kinase inhibitors were either unchanged (p16, p18, p21, p27, and p57) or were not detected (p15 and p19). Most significantly, levels of cyclins D1 and D2 were markedly diminished with Cdx1 expression, but not cyclins D3, E, or the G(1) kinases. Additionally, cyclin-dependent kinase-4 activity was decreased in association with decreased cyclin D protein. We conclude that Cdx1 regulates intestinal epithelial cell proliferation by inhibiting progression through G(0)/G(1), most likely via modulation of cyclin D1 and D2 protein levels.
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Affiliation(s)
- J Lynch
- Division of Gastroenterology, Department of Medicine and Genetics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Ren P, Silberg DG, Sirica AE. Expression of an intestine-specific transcription factor (CDX1) in intestinal metaplasia and in subsequently developed intestinal type of cholangiocarcinoma in rat liver. Am J Pathol 2000; 156:621-7. [PMID: 10666391 PMCID: PMC1850055 DOI: 10.1016/s0002-9440(10)64766-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/02/1999] [Indexed: 11/30/2022]
Abstract
CDX1 is a caudal-type homeobox intestine-specific transcription factor that has been shown to be selectively expressed in epithelial cells in intestinal metaplasia of the human stomach and esophagus and variably expressed in human gastric and esophageal adenocarcinomas (Silberg DG, Furth EE, Taylor JK, Schuck T, Chiou T, Traber PG: Gastroenterology 1997, 113: 478-486). Through the use of immunohistochemistry and Western blotting, we investigated whether CDX1 is also uniquely associated with the intestinal metaplasia associated with putative precancerous cholangiofibrosis induced in rat liver during furan cholangiocarcinogenesis, as well as expressed in neoplastic glands in a subsequently developed intestinal type of cholangiocarcinoma. In normal, control adult rat small intestine, specific nuclear immunoreactivity for CDX1 was most prominent in enterocytes lining the crypts. In comparison, epithelium from intestinal metaplastic glands within furan-induced hepatic cholangiofibrosis and neoplastic epithelium from later developed primary intestinal-type cholangiocarcinoma each demonstrated strong nuclear immunoreactivity for CDX1. CDX1-positive cells were detected in hepatic cholangiofibrotic tissue as early as 3 weeks after the start of chronic furan treatment. We further determined that the percentages of CDX1-positive neoplastic glands and glandular nuclei are significantly higher in primary tumors than in a derived, transplantable cholangiocarcinoma serially-propagated in vivo. Western blotting confirmed our immunohistochemical results, and no CDX1 immunoreactivity was detected in normal adult rat liver or in hyperplastic biliary epithelial cells. These findings indicate that CDX1 is specifically associated with early intestinal metaplasia and a later developed intestinal-type of cholangiocarcinoma induced in the liver of furan-treated rats.
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Affiliation(s)
- P Ren
- Department of Pathology, Division of Cellular Pathogenesis, Medical College of Virginia, Campus of Virginia Commonwealth University, Richmond, Virginia, USA
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Cañete-Soler R, Silberg DG, Gershon MD, Schlaepfer WW. Mutation in neurofilament transgene implicates RNA processing in the pathogenesis of neurodegenerative disease. J Neurosci 1999; 19:1273-83. [PMID: 9952405 PMCID: PMC6786029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/1998] [Revised: 11/23/1998] [Accepted: 11/25/1998] [Indexed: 02/10/2023] Open
Abstract
A mouse neurofilament light subunit (NF-L) transgene with a 36 bp c-myc insert at the end of the coding region was found to have neuropathic effects on enteric and motor neurons of transgenic mice. The severity of phenotype was related directly to the levels of transgenic mRNA expression. High levels of transgene expression were lethal to newborn pups, causing profound alterations in the development of the enteric nervous system and extensive vacuolar changes in motor neurons. Lower levels of transgene expression led to a transient stunting of growth and focal alterations of enteric and motor neurons. Because the positioning of the c-myc insert coincided with the location of the major stability determinant of the NF-L mRNA (Cañete-Soler et al., 1998a,b), additional studies were undertaken. These studies showed that the c-myc insert alters the ribonucleoprotein (RNP) complexes that bind to the stability determinant and disrupts their ability to regulate the stability of the transcripts. The findings indicate that expression of an NF-L transgene with a mutant mRNA stability determinant is highly disruptive to enteric and motor neurons and implicate alterations in RNA processing in the pathogenesis of a neurodegenerative condition.
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Affiliation(s)
- R Cañete-Soler
- Division of Neuropathology, University of Pennsylvania Medical School, Philadelphia, Pennsylvania 19104-6079, USA
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35
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Moseley RH, Höglund P, Wu GD, Silberg DG, Haila S, de la Chapelle A, Holmberg C, Kere J. Downregulated in adenoma gene encodes a chloride transporter defective in congenital chloride diarrhea. Am J Physiol 1999; 276:G185-92. [PMID: 9886994 DOI: 10.1152/ajpgi.1999.276.1.g185] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Congenital chloride diarrhea (CLD) is a recessively inherited disorder characterized by massive loss of chloride in stool. We previously identified mutations in the downregulated in adenoma (DRA) gene in patients with CLD and demonstrated that DRA encodes an intestine-specific sulfate transporter. To determine whether DRA is an intestinal chloride transporter and how mutations affect transport, Xenopus oocytes were injected with wild-type and mutagenized DRA cRNA and uptake of Cl- and SO2-4 was assayed. Both Cl- and SO2-4 were transported by wild-type DRA and an outwardly directed pH gradient stimulated Cl- uptake, consistent with Cl-/OH- exchange. Among three mutants, C307W transported both anions as effectively as wild-type, whereas transport activity was lost in V317del and the double mutant identified in 32 of 32 Finnish CLD patients. We conclude that DRA is a chloride transporter defective in CLD and that V317del is a functional mutation and C307W a silent polymorphism.
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Affiliation(s)
- R H Moseley
- Department of Internal Medicine, Veterans Affairs Medical Center and University of Michigan School of Medicine, Ann Arbor, Michigan 48105, USA
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Yang H, Jiang W, Furth EE, Wen X, Katz JP, Sellon RK, Silberg DG, Antalis TM, Schweinfest CW, Wu GD. Intestinal inflammation reduces expression of DRA, a transporter responsible for congenital chloride diarrhea. Am J Physiol 1998; 275:G1445-53. [PMID: 9843783 DOI: 10.1152/ajpgi.1998.275.6.g1445] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The pathogenesis of diarrhea in intestinal inflammatory states is a multifactorial process involving the effects of inflammatory mediators on epithelial transport function. The effect of colonic inflammation on the gene expression of DRA (downregulated in adenoma), a chloride-sulfate anion transporter that is mutated in patients with congenital chloridorrhea, was examined in vivo as well as in an intestinal epithelial cell line. DRA mRNA expression was diminished five- to sevenfold in the HLA-B27/beta2m transgenic rat compared with control. In situ hybridization showed that DRA, which is normally expressed in the upper crypt and surface epithelium of the colon, was dramatically reduced in the surface epithelium of the HLA-B27/beta2m transgenic rat, the interleukin-10 (IL-10) knockout mouse with spontaneous colitis, and in patients with ulcerative colitis. Immunohistochemistry demonstrated that mRNA expression of DRA reflected that of protein expression in vivo. IL-1beta reduced DRA mRNA expression in vitro by inhibiting gene transcription. The loss of transport function in the surface epithelium of the colon by attenuation of transporter gene expression, perhaps inhibited at the level of gene transcription by proinflammatory cytokines, may play a role in the pathogenesis of diarrhea in colitis.
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Affiliation(s)
- H Yang
- Department of Internal Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
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Abstract
BACKGROUND & AIMS CDX1 is an intestine-specific transcription factor expressed early in intestinal development that may be involved in regulation of proliferation and differentiation of intestinal epithelial cells. We examined the pattern of CDX1 protein expression in metaplastic and neoplastic tissue to provide insight into its possible role in abnormal differentiation. METHODS Tissue samples were stained by immunohistochemistry using an affinity-purified, polyclonal antibody against a peptide epitope of CDX1. RESULTS Specific nuclear staining was found in epithelial cells of the small intestine and colon. Esophagus and stomach did not express CDX1 protein; however, adjacent areas of intestinal metaplastic tissue intensely stained for CDX1. Adenocarcinomas of the stomach and esophagus had both positive and negative nuclear staining for CDX1. Colonic epithelial cells in adenomatous polyps and adenocarcinomas had a decreased intensity of staining compared with normal colonic crypts in the same specimen. CONCLUSIONS CDX1 may be important in the transition from normal gastric and esophageal epithelium to intestinal-type metaplasia. The variability in expression of CDX1 in gastric and esophageal adenocarcinomas suggests more than one pathway in the development of these carcinomas. The decrease of CDX1 in colonic adenocarcinomas may indicate a role for CDX1 in growth regulation and in the maintenance of the differentiated phenotype.
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Affiliation(s)
- D G Silberg
- Department of Medicine, University of Pennsylvania, Philadelphia, USA
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Abstract
The winged helix transcription factor Fkh6 is expressed in the mesoderm of the gastrointestinal tract directly adjacent to the endoderm-derived epithelium. Homozygous null mice for Fkh6 showed postnatal growth retardation secondary to severe structural abnormalities of the stomach, duodenum, and jejunum. Dysregulation of epithelial cell proliferation in these organs resulted in an approximately fourfold increase in the number of dividing intestinal epithelial cells and marked expansion of the proliferative zone. As a consequence, the tissue architecture of the stomach and small intestine was distorted, with abnormal crypt structure, formation of mucin filled cysts, and lengthening of villi. Changes in the cellular phenotype and composition of the gastric and intestinal epithelia also suggests that epithelial cell-lineage allocation or differentiation may be affected by loss of Fkh6. From the analysis of a number of potential signaling molecules, we found Bmp2 and Bmp4 expression reduced in the gastrointestinal tract of Fkh6 mutant mice, suggesting that Fkh6 directs a signaling cascade that mediates communication between the mesenchyme and endoderm of the gut to regulate cell proliferation.
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Affiliation(s)
- K H Kaestner
- Department of Genetics, University of Pennsylvania School of Medicine, Philadelphia 19104-6145, USA.
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Tung J, Markowitz AJ, Silberg DG, Traber PG. Developmental expression of SI is regulated in transgenic mice by an evolutionarily conserved promoter. Am J Physiol 1997; 273:G83-92. [PMID: 9252513 DOI: 10.1152/ajpgi.1997.273.1.g83] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Developmental expression of the sucrase-isomaltase (SI) gene in the mouse intestine involves two major transitions that correspond to critical developmental events. Low levels of SI mRNA were first identified in day 16.5 fetal mouse intestine, immediately after the transition from stratified endoderm to a columnar epithelium organized in nascent villi. Low levels were maintained until the third week of life, when induction of SI mRNA to adult levels was observed coincident with the time of weaning. The mechanism of this pattern of SI gene expression was studied in transgenic mice using a reporter gene construct containing an SI gene promoter that is evolutionarily conserved between mouse and human (nucleotides -201 to +54 of the mouse SI gene). This promoter included the necessary regulatory information to direct transcription to enterocytes in developmental and differentiation-dependent patterns that recapitulated the expression of the endogenous SI gene. However, transgenes lacked the ability to direct induction of precocious expression in suckling animals after administration of corticosteroids. These findings define a short SI gene promoter that contains cis-acting elements that are responsible for developmental and differentiation-dependent transcriptional regulation.
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Affiliation(s)
- J Tung
- Department of Medicine, University of Pennsylvania, Philadelphia 19104, USA
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Kaestner KH, Silberg DG, Traber PG, Schütz G. The mesenchymal winged helix transcription factor Fkh6 is required for the control of gastrointestinal proliferation and differentiation. Genes Dev 1997; 11:1583-95. [PMID: 9203584 DOI: 10.1101/gad.11.12.1583] [Citation(s) in RCA: 182] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The winged helix transcription factor Fkh6 is expressed in the mesoderm of the gastrointestinal tract directly adjacent to the endoderm-derived epithelium. Homozygous null mice for Fkh6 showed postnatal growth retardation secondary to severe structural abnormalities of the stomach, duodenum, and jejunum. Dysregulation of epithelial cell proliferation in these organs resulted in an approximately fourfold increase in the number of dividing intestinal epithelial cells and marked expansion of the proliferative zone. As a consequence, the tissue architecture of the stomach and small intestine was distorted, with abnormal crypt structure, formation of mucin filled cysts, and lengthening of villi. Changes in the cellular phenotype and composition of the gastric and intestinal epithelia also suggests that epithelial cell-lineage allocation or differentiation may be affected by loss of Fkh6. From the analysis of a number of potential signaling molecules, we found Bmp2 and Bmp4 expression reduced in the gastrointestinal tract of Fkh6 mutant mice, suggesting that Fkh6 directs a signaling cascade that mediates communication between the mesenchyme and endoderm of the gut to regulate cell proliferation.
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Affiliation(s)
- K H Kaestner
- Department of Genetics, University of Pennsylvania School of Medicine, Philadelphia 19104-6145, USA.
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Abstract
The diverse cellular lineages that populate the intestinal epithelium are derived from committed stem cells located in intestinal crypts. The complex architecture of the intestinal epithelium results from well-orchestrated processes of cell-line-age allocation, proliferation of immature cells in the crypt compartment, differentiation of various cell lineages, migration of cells in defined patterns, and cell-specific programmed senescence. The patterns of intestinal gene transcription in the context of this complex architecture are regulated by the combinatorial effect of multiple positive and negative regulatory elements. Although the DNA regulatory elements required to recapitulate the pattern of endogenous gene expression appear to be spread over relatively large genomic distances, short promoters of several intestinal genes are sufficient to direct intestine-specific transcription. The sucrase-isomaltase gene promoter has multiple regulatory elements that bind tissue-restricted transcription factors. A critical factor in regulating the sucrase-isomaltase promoter is Cdx2, an intestine-specific homeobox gene related to caudal, that may also have a broader role in intestinal development and morphogenesis. As additional regulatory elements and their cognate DNA-binding proteins are identified, the challenge will be to define their integrated role in the regulation of intestine-specific genes and in the development and maintenance of the intestinal epithelium.
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Affiliation(s)
- P G Traber
- Department of Medicine, University of Pennsylvania, Philadelphia 19104-6144, USA
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Diamond RH, Peters C, Jung SP, Greenbaum LE, Haber BA, Silberg DG, Traber PG, Taub R. Expression of PRL-1 nuclear PTPase is associated with proliferation in liver but with differentiation in intestine. Am J Physiol 1996; 271:G121-9. [PMID: 8760115 DOI: 10.1152/ajpgi.1996.271.1.g121] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Mechanisms controlling the tyrosine phosphorylation of cellular proteins are important in the regulation of cellular processes including growth and differentiation. It has become clear that a number of protein tyrosine phosphatases (PTPases) that dephosphorylate tyrosyl residues may play a role in the growth response, both in growth-promoting and growth-inhibiting capacities. We identified PRL-1, a unique nuclear PTPase that is an immediate-early gene in liver regeneration and is positively associated with growth, including fetal and neoplastic hepatic growth and anchorage-independent growth after overexpression in fibroblasts. In this study, we show that PRL-1 nuclear protein levels in regenerating liver parallel those of its mRNA, although the peak occurs later, just before the onset of DNA synthesis. We further show that PRL-1 is significantly expressed in intestinal epithelia and that, in contrast to the expression pattern of PRL-1 in liver, its expression is associated with cellular differentiation in intestine. Specifically, PRL-1 is expressed in villus but not crypt enterocytes and in confluent differentiated but not undifferentiated proliferating Caco-2 colon carcinoma cells. The expression of PRL-1 in intestine shows inverse correlation with proliferating cell nuclear antigen expression, a marker for S-phase cells. These results suggest that PRL-1 may play different roles in these two digestive tissues. Such a dichotomy of roles has previously been described for some protein tyrosine kinases and might be due to the availability of alternate substrates in different tissues.
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Affiliation(s)
- R H Diamond
- Department of Genetics, Children's Hospital, University of Pennsylvania School of Medicine, Philadelphia 19104-6145, USA
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Silberg DG, Wang W, Moseley RH, Traber PG. The Down regulated in Adenoma (dra) gene encodes an intestine-specific membrane sulfate transport protein. J Biol Chem 1995; 270:11897-902. [PMID: 7744840 DOI: 10.1074/jbc.270.20.11897] [Citation(s) in RCA: 111] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
A gene has been described, Down Regulated in Adenoma (dra), which is expressed in normal colon but is absent in the majority of colon adenomas and adenocarcinomas. However, the function of this protein is unknown. Because of sequence similarity to a recently cloned membrane sulfate transporter in rat liver, the transport function of Dra was examined. We established that dra encodes for a Na(+)-independent transporter for both sulfate and oxalate using microinjected Xenopus oocytes as an assay system. Sulfate transport was sensitive to the anion exchange inhibitor DIDS (4,4'-diisothiocyano-2,2' disulfonic acid stilbene). Using an RNase protection assay, we found that dra mRNA expression is limited to the small intestine and colon in mouse, therefore identifying Dra as an intestine-specific sulfate transporter. dra also had a unique pattern of expression during intestinal development. Northern blot analysis revealed a low level of expression in colon at birth with a marked increase in the first 2 postnatal weeks. In contrast, there was a lower, constant level of expression in small intestine in the postnatal period. Caco-2 cells, a colon carcinoma cell line that differentiates over time in culture, demonstrated a marked induction of dra mRNA as cells progressed from the preconfluent (undifferentiated) to the postconfluent (differentiated) state. These results show that Dra is an intestine-specific Na(+)-independent sulfate transporter that has differential expression during colonic development. This functional characterization provides the foundation for investigation of the role of Dra in intestinal sulfate transport and in the malignant phenotype.
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Affiliation(s)
- D G Silberg
- Department of Medicine and Genetics, University of Pennsylvania, Philadelphia 19104, USA
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Hirsch JA, Levine MS, Silberg DG, Philippe L. Small-cell carcinoma of the esophagus with regression after combination chemotherapy and radiation therapy. Can Assoc Radiol J 1995; 46:45-7. [PMID: 7834487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The authors present an unusual case of small-cell carcinoma of the esophagus, which manifested on double-contrast esophagography as an ulcerated submucosal mass. The lesion underwent dramatic regression after combination chemotherapy and radiation therapy, which has occasionally been used as an alternative to surgery in patients with this rare but aggressive esophageal neoplasm.
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Affiliation(s)
- J A Hirsch
- Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia 19104
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Abstract
This paper describes our ongoing investigation of the activation of effector cells of experimental allergic encephalomyelitis (EAE) from nonimmune Lewis rats by sequential culture of spleen cells (SpC) with myelin basic protein (BP) and transfer to syngeneic recipients. We show that SpC initiate the effector cell activation process, whereas thymocytes (Thy) are ineffective. Intermediary recipients of BP-cultured SpC are 'primed' for EAE, but do not develop the disease; this primed state persists for at least 2 months. No evidence was found that suppressor cells account for the failure of the intermediary recipients to develop EAE. The activation process can be inhibited by including monoclonal anti-Ia antibody in the primary culture, indicating that multiple triggering signals are involved in the activation of autoreactive T cells.
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Affiliation(s)
- N S Hayosh
- Department of Immunology and Microbiology, Wayne State University School of Medicine, Detroit, MI 48201
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Silberg DG, Swanborg RH. Autoimmune effector cells. VIII. Cellular requirements for the induction of autoreactive T cells of experimental allergic encephalomyelitis in nonimmune rats. J Immunol 1986; 136:2432-6. [PMID: 3485150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We utilized a system of sequential in vitro cell culture and adoptive transfer to investigate the sequence of events which lead to the activation of effector cells responsible for the induction of experimental autoimmune encephalomyelitis (EAE) in Lewis rats. This procedure involves only naive (nonimmune) rats, and eliminates the requirement for adjuvants. Spleen cells (SpC) from naive donors were sensitized in vitro to myelin basic protein (BP), then transferred to intermediate (primary) hosts. Although these recipients did not develop EAE, they were primed for disease because they exhibited accelerated onset of active EAE when challenged with BP in adjuvant. Moreover, SpC from nonchallenged primary recipients transferred EAE to secondary recipients subsequent to in vitro exposure to antigen. The cells from the naive cultures which primed the intermediate recipients were radioresistant (1500 R); other studies have indicated that these are macrophages. In contrast, the cells which transferred EAE to the secondary recipients were radiation-sensitive T lymphoblasts. The finding that these cells also elicit disease in lethally irradiated (850 R) secondary recipients suggests that the transferred cells either are the actual effector cells of EAE or induce disease in collaboration only with radioresistant host cells.
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Silberg DG, Swanborg RH. Autoimmune effector cells. VIII. Cellular requirements for the induction of autoreactive T cells of experimental allergic encephalomyelitis in nonimmune rats. The Journal of Immunology 1986. [DOI: 10.4049/jimmunol.136.7.2432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
We utilized a system of sequential in vitro cell culture and adoptive transfer to investigate the sequence of events which lead to the activation of effector cells responsible for the induction of experimental autoimmune encephalomyelitis (EAE) in Lewis rats. This procedure involves only naive (nonimmune) rats, and eliminates the requirement for adjuvants. Spleen cells (SpC) from naive donors were sensitized in vitro to myelin basic protein (BP), then transferred to intermediate (primary) hosts. Although these recipients did not develop EAE, they were primed for disease because they exhibited accelerated onset of active EAE when challenged with BP in adjuvant. Moreover, SpC from nonchallenged primary recipients transferred EAE to secondary recipients subsequent to in vitro exposure to antigen. The cells from the naive cultures which primed the intermediate recipients were radioresistant (1500 R); other studies have indicated that these are macrophages. In contrast, the cells which transferred EAE to the secondary recipients were radiation-sensitive T lymphoblasts. The finding that these cells also elicit disease in lethally irradiated (850 R) secondary recipients suggests that the transferred cells either are the actual effector cells of EAE or induce disease in collaboration only with radioresistant host cells.
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