Linked Life Data

11905052

Source:http://linkedlifedata.com/resource/pubmed/id/11905052

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2002-3-21
pubmed:abstractText
We have previously reported that cisplatin induces caspase-9 activation in head and neck squamous cell carcinoma cells (HNSCCs) in vitro, and the use of a specific inhibitor of caspase-9 blocks cisplatin-induced apoptosis in HNSCCs. Our purpose here was to determine whether HNSCCs selected for resistance to cisplatin fail to exhibit caspase-9 activation in response to cisplatin. Cisplatin-resistant HNSCCs (CRHNSCCs) were selected for growth in the presence of cisplatin. Following cisplatin treatment, no protelyzed caspase-9 subunits were detected in the CRHNSCCs, whereas proteolytic degradation of procaspase-9 was observed in parental cisplatin-sensitive HNSCCs (CSHNSCCs). Using a direct enzymatic assay measuring cleavage of the synthetic peptide substrate (LEHD-AFC), caspase-9 activity in cisplatin-treated CRHNSCCs was less than that in cisplatin-treated CSHNSCCs. Because caspase-9 activation requires the release of mitochondorial cytochrome c (Cyt c) into the cytoplasm, we determined the level of cytoplasmic Cyt c in response to cisplatin treatment. Interestingly, following cisplatin treatment, the same extent of increase in cytoplasmic Cyt c was evident and the expression of Bcl-2 family proteins (Bcl-2 and Bcl-XL) remained unchanged in both CRHNSCCs and CSHNSCCs. These results suggest that in certain HNSCC cell types, inhibition of caspase-9 activity represents another mechanism of acquired cisplatin resistance. This inhibition mechanism may be independent of the release of Cyt c into the cytoplasm.
pubmed:language
jpn
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0030-6622
pubmed:author
pubmed:issnType
Print
pubmed:volume
105
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
152-7
pubmed:dateRevised
2011-7-28
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
[Inhibition of caspase-9 activity in cisplatin-resistant head and neck squamous cell carcinoma].
pubmed:affiliation
Department of Otolaryngology, St. Marianna University School of Medicine, Kawasaki.
pubmed:publicationType
Journal Article, English Abstract, Research Support, Non-U.S. Gov't