Linked Life Data

17693058

Source:http://linkedlifedata.com/resource/pubmed/id/17693058

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2007-9-10
pubmed:abstractText
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has recently emerged as a cancer therapeutic agent because it is capable of preferentially inducing apoptosis in human cancer over normal cells. The majority of human pancreatic cancers, unfortunately, are resistant to TRAIL treatment. Here, we show that the inhibition of caspase-8 cleavage is the most upstream event in TRAIL resistance in pancreatic cancers. TRAIL treatment led to the cleavage of caspase-8 and downstream caspase-9, caspase-3, and DNA fragmentation factor 45 (DFF45) in TRAIL-sensitive pancreatic cancer cell lines (BXPC-3, PACA-2). This caspase-8-initiated caspase cascade, however, was inhibited in TRAIL-resistant pancreatic cancer cell lines (PANC-1, ASPC-1, CAPAN-1, CAPAN-2). The long and short forms of cellular Fas-associated death domain-like interleukin-1beta-converting enzyme-inhibitory protein (c-FLIP(L), c-FLIP(S)) were highly expressed in the TRAIL-resistant as compared to the sensitive cells; knockdown of c-FLIP(L) and c-FLIP(S) by a short hairpin RNA (shRNA) rendered the resistant cells sensitive to TRAIL-induced apoptosis through the cleavage of caspase-8 and activation of the mitochondrial pathway. Receptor-interacting protein (RIP) has been reported in TRAIL-induced activation of NF-kappaB and we show here that knockdown of RIP sensitized the resistant cells to TRAIL-induced apoptosis. These results indicate the role of c-FLIP and RIP in caspase-8 inhibition and thus TRAIL resistance. Treatment of the resistant cells with camptothecin, celecoxib and cisplatin resulted in the downregulation of c-FLIP and caused a synergistic apoptotic effect with TRAIL. These studies therefore suggest that combination treatment with chemotherapy can overcome TRAIL resistance and enhance TRAIL therapeutic efficacy in treating pancreatic cancers.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0898-6568
pubmed:author
pubmed:issnType
Print
pubmed:volume
19
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2237-46
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Inhibition of RIP and c-FLIP enhances TRAIL-induced apoptosis in pancreatic cancer cells.
pubmed:affiliation
Department of Laboratory Medicine and Pathology and Surgery, University of Alberta, Edmonton, Alberta, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't