Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2007-3-21
pubmed:abstractText
The importance of the arachidonic acid pathway has been established in colon and lung cancers, as well as in inflammatory diseases. In these diseases, prostacyclin I(2) (PGI2) and prostaglandin E(2) (PGE2) are thought to have antagonistic activities, with PGI2 exerting anti-inflammatory and antiproliferative activities, whereas PGE2 is proinflammatory and antiapoptotic. In human lung cancer, prostacyclin synthase (PGIS) and PGI2 are down-regulated, whereas PGE2 synthase (PGES) and PGE2 are up-regulated. Murine carcinogenesis models of human lung cancer reciprocate the relationship between PGIS and PGES expression. PGIS-overexpressing transgenic mice are protected from carcinogen- and tobacco smoke-induced lung tumor formation, suggesting that PGI2 may play a role in chemoprevention. We investigated several potential mechanisms for the down-regulation of PGIS in human lung cancer. Using transcription reporter assays, we show that single nucleotide polymorphisms in the PGIS promoter can affect transcriptional activity. In addition, PGIS expression in several human lung cancer cell lines is silenced by CpG methylation, and we have mapped these sites across the variable number of tandem repeats (VNTR) sequence in the promoter, as well as CpGs within exon 1 and the first intron. Finally, using fluorescence in situ hybridization, we show that human lung cancer cell lines and lung cancer tissues do not have a loss of the PGIS genomic region but multiple copies. These results show that an individual's PGIS promoter haplotype can play an important role in the predisposition for lung cancer and CpG methylation provides an epigenetic mechanism for the down-regulated PGIS expression.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1541-7786
pubmed:author
pubmed:issnType
Print
pubmed:volume
5
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
295-308
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:17374734-Base Sequence, pubmed-meshheading:17374734-Cell Line, Tumor, pubmed-meshheading:17374734-CpG Islands, pubmed-meshheading:17374734-Cytochrome P-450 Enzyme System, pubmed-meshheading:17374734-DNA Methylation, pubmed-meshheading:17374734-Down-Regulation, pubmed-meshheading:17374734-Epigenesis, Genetic, pubmed-meshheading:17374734-Gene Expression Regulation, Neoplastic, pubmed-meshheading:17374734-Genes, Reporter, pubmed-meshheading:17374734-Genetic Predisposition to Disease, pubmed-meshheading:17374734-Humans, pubmed-meshheading:17374734-In Situ Hybridization, Fluorescence, pubmed-meshheading:17374734-Intramolecular Oxidoreductases, pubmed-meshheading:17374734-Lung Neoplasms, pubmed-meshheading:17374734-Minisatellite Repeats, pubmed-meshheading:17374734-Molecular Sequence Data, pubmed-meshheading:17374734-Promoter Regions, Genetic, pubmed-meshheading:17374734-RNA, Messenger
pubmed:year
2007
pubmed:articleTitle
Genetic and epigenetic regulation of the human prostacyclin synthase promoter in lung cancer cell lines.
pubmed:affiliation
Department of Medicine, Pulmonary Sciences and Critical Care Division, University of Colorado Health Sciences Center, Denver, CO 80262, USA. robert.stearman@uchsc.edu
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural