Linked Life Data

17172430

Source:http://linkedlifedata.com/resource/pubmed/id/17172430

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2006-12-18
pubmed:abstractText
Photodynamic therapy (PDT) induces the expression of the hypoxia-inducible factor 1alpha (HIF-1alpha) subunit of the HIF-1 transcription factor and its target genes in vitro and in vivo. PDT also induces the expression of the enzyme cyclooxygenase-2 and its metabolite, prostaglandin E2 (PGE2). PGE2 and hypoxia act independently and synergistically to increase HIF-1alpha accumulation and nuclear translocation. To examine the expression of HIF-1 target genes in response to PDT-mediated oxidative stress and PGE2 under normoxic conditions, we established EMT6 cells transfected with a plasmid consisting of a hypoxia response element promoter and a downstream gene encoding for green fluorescent protein (GFP). To examine the temporal kinetics of HIF-1alpha nuclear translocation in response to PDT, we transfected a second line of EMT6 cells with a GFP-tagged HIF-1alpha fusion vector. Cell monolayers were incubated with 1 microg mL(-1) Photofrin for 24 h and irradiated with fluences of 1, 2.5, and 5 J cm(-2). Direct measurement of oxygen concentration during irradiation confirmed that cells remained well oxygenated. Cells were also exposed to 1 and 10 micromol/L PGE2 for 3 h. In normoxic conditions, Photofrin, PDT, and PGE2 treatment activated HIF-1alpha and induced its nuclear translocation. Maximal Photofrin-PDT-mediated HIF-1alpha activation was intermediate in magnitude between that induced by PGE2 and that by the hypoxia mimic cobalt chloride. This work establishes that PDT induces significant activation of the HIF-1alpha pathway in the absence of hypoxia and supports the interpretation that the induction of HIF-1 target genes by PDT may be mediated, at least in part, by the prostaglandin pathway.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1535-7163
pubmed:author
pubmed:issnType
Print
pubmed:volume
5
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3268-74
pubmed:dateRevised
2007-12-3
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Photodynamic therapy mediates the oxygen-independent activation of hypoxia-inducible factor 1alpha.
pubmed:affiliation
Department of Imaging Sciences, University of Rochester, 601 Elmwood Avenue, Box 648, Rochester, NY 14642, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural