Linked Life Data

14612499

Source:http://linkedlifedata.com/resource/pubmed/id/14612499

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
2003-11-12
pubmed:abstractText
We established previously that X-linked inhibitor of apoptosis protein (Xiap) is a determinant of cisplatin (CDDP) resistance in human ovarian cancer cells and that down-regulation of Xiap sensitizes cells to CDDP in the presence of wild-type p53. Furthermore, Xiap up-regulates the phosphatidylinositol 3'-kinase/Akt pathway by increasing Akt phosphorylation. However, the precise relationships among Xiap, Akt, and p53 in chemoresistance are unknown. Here we show that both Xiap and Akt can modulate CDDP sensitivity individually but that Xiap requires Akt for its full function. Furthermore, dominant-negative Akt sensitizes ovarian cancer cells to CDDP (10 micro M), an effect that is absent in cells expressing mutant p53 or treated with the p53 inhibitor pifithrin-alpha-hydrobromide (30 micro M) but restored by exogenous wild-type p53. CDDP increased p53, decreased Xiap content, and induced apoptosis in OV2008 cells but not in the resistant counterpart (C13*). However, dominant-negative Akt restored all of these characteristics to C13* cells. Expression of a constitutively active Akt2 prevented CDDP-mediated down-regulation of Xiap and apoptosis in A2780s cells. Akt2-mediated chemoresistance could not be reversed by Xiap down-regulation. These results suggest that whereas Xiap, Akt2, and p53 are important mediators of chemoresistance in ovarian cancer cells, Akt2 may be an important regulator of both Xiap and p53 contents after CDDP challenge. Inhibition of Xiap and/or Akt expression/function may be an effective means of overcoming chemoresistance in ovarian cancer cells expressing either endogenous or reconstituted wild-type p53.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/AKT1 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/AKT2 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Antineoplastic Agents, http://linkedlifedata.com/resource/pubmed/chemical/Cisplatin, http://linkedlifedata.com/resource/pubmed/chemical/Protein-Serine-Threonine Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Proto-Oncogene Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Proto-Oncogene Proteins c-akt, http://linkedlifedata.com/resource/pubmed/chemical/Tumor Suppressor Protein p53, http://linkedlifedata.com/resource/pubmed/chemical/X-Linked Inhibitor of Apoptosis..., http://linkedlifedata.com/resource/pubmed/chemical/XIAP protein, human
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0008-5472
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
63
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7081-8
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
p53 is a determinant of X-linked inhibitor of apoptosis protein/Akt-mediated chemoresistance in human ovarian cancer cells.
pubmed:affiliation
Reproductive Biology Unit and Division of Gynaecological Oncology, Department of Obstetrics and Gynaecology, University of Ottawa, Ottawa Health Research Institute, 725 Parkdale Avenue, Ottawa, Ontario KIY 4E9, Canada.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't