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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2010-2-15
pubmed:abstractText
In many tumor cell types, ionizing radiation or DNA-damaging anticancer drugs enhance sensitivity to death receptor-mediated apoptosis, which is of clinical interest. APO010, a form of CD95/Fas ligand is currently in a phase I trial in patients with solid tumors. To analyze the potential of combined modality treatment with APO010, we used p53-mutant Jurkat T leukemic cells, in which the mitochondrial pathway was blocked by Bcl-2 overexpression. These cells were strongly sensitized to APO010 by pretreatment with ionizing - or UV radiation, etoposide, histone deacetylase - or proteasome inhibitors. These stimuli alone did not induce apoptosis in J16-Bcl-2 cells. Sensitization could not be explained by the overruling of mitochondrial resistance imposed by Bcl-2, upregulation of CD95 membrane levels or modulation of inhibitor of apoptosis proteins. Rather, the stimuli commonly downregulated c-FLIP(L/S) protein levels, which was causally related to the sensitization: deliberate c-FLIP(L/S) downregulation by RNA interference largely overruled the capacity of the various stimuli to sensitize Jurkat-Bcl-2 cells to apoptotic execution by APO010. In p53-mutant, Bcl-2 overexpressing HCT-15 colon carcinoma cells, c-FLIP downregulation correlated with sensitization to APO010 for some, but not all stimuli. We conclude that c-FLIP downregulation represents a mechanism by which diverse anticancer regimens can facilitate tumor cell execution by CD95/Fas through the direct pathway of caspase activation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1476-5403
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
17
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
551-61
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Radiation and anticancer drugs can facilitate mitochondrial bypass by CD95/Fas via c-FLIP downregulation.
pubmed:affiliation
Division of Immunology, The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't