title: Gene expression changes associated with Barrett's esophagus and Barrett's-associated adenocarcinoma cell lines after acid or bile salt exposure.
abstract: BACKGROUND
  Esophageal reflux and Barrett's esophagus represent two major risk factors for the development of esophageal adenocarcinoma. Previous studies have shown that brief exposure of the Barrett's-associated adenocarcinoma cell line, SEG-1, or primary cultures of Barrett's esophageal tissues to acid or bile results in changes consistent with cell proliferation. In this study, we determined whether similar exposure to acid or bile salts results in gene expression changes that provide insights into malignant transformation.
  
  
  METHODS
  Using previously published methods, Barrett's-associated esophageal adenocarcinoma cell lines and primary cultures of Barrett's esophageal tissue were exposed to short pulses of acid or bile salts followed by incubation in culture media at pH 7.4. A genome-wide assessment of gene expression was then determined for the samples using cDNA microarrays. Subsequent analysis evaluated for statistical differences in gene expression with and without treatment.
  
  
  RESULTS
  The SEG-1 cell line showed changes in gene expression that was dependent on the length of exposure to pH 3.5. Further analysis using the Gene Ontology, however, showed that representation by genes associated with cell proliferation is not enhanced by acid exposure. The changes in gene expression also did not involve genes known to be differentially expressed in esophageal adenocarcinoma. Similar experiments using short-term primary cultures of Barrett's esophagus also did not result in detectable changes in gene expression with either acid or bile salt exposure.
  
  
  CONCLUSIONS
  Short-term exposure of esophageal adenocarcinoma SEG-1 cells or primary cultures of Barrett's esophagus does not result in gene expression changes that are consistent with enhanced cell proliferation. Thus other model systems are needed that may reflect the impact of acid and bile salt exposure on the esophagus in vivo.
authors.affiliation: Department of Medicine, Stanford University, Stanford, CA, USA. yhao@stanford.edu <yhao@stanford.edu>
authors.forename: Ying
authors.initials: Y
authors.lastname: Hao
authors.forename: Sumita
authors.initials: S
authors.lastname: Sood
authors.forename: George
authors.initials: G
authors.lastname: Triadafilopoulos
authors.forename: Jong Hyeok
authors.initials: JH
authors.lastname: Kim
authors.forename: Zheng
authors.initials: Z
authors.lastname: Wang
authors.forename: Peyman
authors.initials: P
authors.lastname: Sahbaie
authors.forename: M Bishr
authors.initials: MB
authors.lastname: Omary
authors.forename: Anson W
authors.initials: AW
authors.lastname: Lowe
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000473:pathology; D001471:Barrett Esophagus / Q000235:genetics / Q000473:pathology; D001647:Bile Acids and Salts / Q000494:pharmacology*; D045744:Cell Line, Tumor / Q000187:drug effects; D002471:Cell Transformation, Neoplastic / Q000235:genetics*; D018076:DNA, Complementary / Q000235:genetics; D004273:DNA, Neoplasm / Q000032:analysis; D004938:Esophageal Neoplasms / Q000235:genetics / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis; D012680:Sensitivity and Specificity
chemical_list: D001647:Bile Acids and Salts; D018076:DNA, Complementary; D004273:DNA, Neoplasm