Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2011-7-28
pubmed:abstractText
Gastroesophageal reflux is associated with adenocarcinoma in Barrett's esophagus, but the incidence of this tumor is rising, despite widespread use of acid-suppressing medications. This suggests that refluxed material other than acid might contribute to carcinogenesis. We looked for potentially carcinogenetic effects of two bile acids, deoxycholic acid (DCA) and ursodeoxycholic acid (UDCA), on Barrett's epithelial cells in vitro and in vivo. We exposed Barrett's (BAR-T) cells to DCA or UDCA and studied the generation of reactive oxygen/nitrogen species (ROS/RNS); expression of phosphorylated H2AX (a marker of DNA damage), phosphorylated IkB?, and phosphorylated p65 (activated NF-?B pathway proteins); and apoptosis. During endoscopy in patients, we took biopsy specimens of Barrett's mucosa before and after esophageal perfusion with DCA or UDCA and assessed DNA damage and NF-?B activation. Exposure to DCA, but not UDCA, resulted in ROS/RNS production, DNA damage, and NF-?B activation but did not increase the rate of apoptosis in BAR-T cells. Pretreatment with N-acetyl-l-cysteine (a ROS scavenger) prevented DNA damage after DCA exposure, and DCA did induce apoptosis in cells treated with NF-?B inhibitors (BAY 11-7085 or AdI?B superrepressor). DNA damage and NF-?B activation were detected in biopsy specimens of Barrett's mucosa taken after esophageal perfusion with DCA, but not UDCA. These data show that, in Barrett's epithelial cells, DCA induces ROS/RNS production, which causes genotoxic injury, and simultaneously induces activation of the NF-?B pathway, which enables cells with DNA damage to resist apoptosis. We have demonstrated molecular mechanisms whereby bile reflux might contribute to carcinogenesis in Barrett's esophagus.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1522-1547
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
301
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
G278-86
pubmed:meshHeading
pubmed-meshheading:21636532-Aged, pubmed-meshheading:21636532-Analysis of Variance, pubmed-meshheading:21636532-Animals, pubmed-meshheading:21636532-Apoptosis, pubmed-meshheading:21636532-Barrett Esophagus, pubmed-meshheading:21636532-Cell Line, pubmed-meshheading:21636532-Cell Transformation, Neoplastic, pubmed-meshheading:21636532-DNA Damage, pubmed-meshheading:21636532-Deoxycholic Acid, pubmed-meshheading:21636532-Epithelial Cells, pubmed-meshheading:21636532-Histones, pubmed-meshheading:21636532-Humans, pubmed-meshheading:21636532-I-kappa B Proteins, pubmed-meshheading:21636532-Male, pubmed-meshheading:21636532-Middle Aged, pubmed-meshheading:21636532-NF-kappa B, pubmed-meshheading:21636532-Rats, pubmed-meshheading:21636532-Reactive Nitrogen Species, pubmed-meshheading:21636532-Reactive Oxygen Species, pubmed-meshheading:21636532-Signal Transduction, pubmed-meshheading:21636532-Ursodeoxycholic Acid
pubmed:year
2011
pubmed:articleTitle
Deoxycholic acid causes DNA damage while inducing apoptotic resistance through NF-?B activation in benign Barrett's epithelial cells.
pubmed:affiliation
Department of Medicine, Veterans Affairs North Texas Health Care System, Children’s Medical Center, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, N.I.H., Extramural