Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2000-4-27
pubmed:abstractText
Multidrug resistance (MDR) is often characterized by the expression of P-glycoprotein (P-gp), a 170-kd ATP-dependent drug efflux protein. As well as effluxing xenotoxins, functional P-gp can confer resistance to caspase-dependent apoptosis induced by a range of different stimuli, including Fas ligand, tumor necrosis factor, UV irradiation, and serum starvation. However, P-gp-positive cells remain sensitive to caspase-independent death induced by cytotoxic T-cell granule proteins, perforin, and granzyme B. It is, therefore, possible that agents that induce cell death in a caspase-independent manner might circumvent P-gp-mediated MDR. We demonstrated here that hexamethylene bisacetamide (HMBA) induced equivalent caspase-independent cell death in both P-gp-positive and -negative cell lines at concentrations of 10 mmol/L and above. The HMBA-induced death pathway was marked by release of cytochrome c from the mitochondria and reduction of Bcl-2 protein levels. In addition, we show that functional P-gp specifically inhibits the activation of particular caspases, such as caspases-8 and -3, whereas others, such as caspase-9, remain unaffected. These studies greatly enhance our understanding of the molecular cell death events that can be regulated by functional P-gp and highlight the potential clinical use of drugs that function via a caspase-independent pathway for the treatment of MDR tumors.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-4971
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
95
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2378-85
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
HMBA induces activation of a caspase-independent cell death pathway to overcome P-glycoprotein-mediated multidrug resistance.
pubmed:affiliation
Austin Research Institute, Austin Hospital, Heidelberg, Victoria, Australia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't