Linked Life Data

17230520

Source:http://linkedlifedata.com/resource/pubmed/id/17230520

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2007-3-8
pubmed:abstractText
Selenium is a promising chemopreventive agent for prostate cancer, possibly via an induction of apoptosis. Earlier studies have shown that selenite induces DNA single strand breaks (SSBs), reactive oxygen species (ROS), p53 Ser-15 phosphorylation and caspase-dependent and -independent apoptosis, whereas a methylselenol precursor methylseleninic acid (MSeA) induces caspase-mediated apoptosis regardless of p53 status. Here we address three main questions: What types of ROS are induced by selenite vs. MSeA in LNCaP (p53 wild type, androgen-responsive) and DU145 (mutant p53, androgen-independent) prostate cancer cells? Does ROS generation depend on androgen signaling? What are the relationships among ROS, DNA SSBs, p53 and caspases? We show that selenite (5 microM) induced superoxide and hydrogen peroxide in LNCaP cells much more than in DU145 cells and the ROS generation was not affected by physiological androgen stimulation. MSeA (10 microM) induced apoptosis without either type of ROS in both cell lines. In LNCaP cells, we established superoxide as a primary mediator for selenite-induced DNA SSBs, p53 activation and caspase-mediated apoptosis. Furthermore a p53-dominant negative mutant attenuated selenite-induced ROS, leading to a proportionate protection against apoptosis. The results support the p53-mitochondria axis in a feedback loop for sustaining superoxide production to lead to efficient caspase-mediated apoptosis by selenite. In contrast, caspase-mediated apoptosis induced by MSeA does not involve ROS induction. Since p53 is frequently mutated or deleted in prostate cancer and many other cancers, our results suggest that genotoxic vs. nongenotoxic classes of selenium may exert differential apoptosis efficacy depending on the p53 status of the cancer cells.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0020-7136
pubmed:author
pubmed:copyrightInfo
(c) 2007 Wiley-Liss, Inc.
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
120
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2034-43
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Differential involvement of reactive oxygen species in apoptosis induced by two classes of selenium compounds in human prostate cancer cells.
pubmed:affiliation
Hormel Institute, University of Minnesota, Austin, MN.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, N.I.H., Extramural