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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
2011-5-12
pubmed:abstractText
Despite aggressive therapies, the prognosis of children with high-risk medulloblastoma is still poor, thus underscoring the need to develop novel treatment strategies. Here, we report that histone deacetylase inhibitors (HDACI), that is, MS-275, valproic acid or SAHA, provide a novel strategy for sensitization of medulloblastoma to DNA-damaging drugs such as Doxorubicin, VP16 and Cisplatin by promoting p53-dependent, mitochondrial apoptosis. Mechanistic studies reveal that single-agent treatment with MS-275 causes acetylation of the non-histone protein Ku70, an event reported to release Bax from Ku70, whereas DNA-damaging drugs trigger p53 acetylation and accumulation. Combined treatment with MS-275 and Doxorubicin or VP16 cooperates to promote binding of p53 to Bax and p53-dependent Bax activation, resulting in enhanced loss of mitochondrial membrane potential, cytochrome c release and caspase-dependent apoptosis. Overexpression of Bcl-2 almost completely abolishes the MS-275-mediated chemosensitization, underlining the importance of the mitochondrial pathway for inducing apoptosis. Also, MS-275 cooperates with chemotherapeutics to inhibit long-term clonogenic survival. Most importantly, MS-275 increases chemotherapeutic drug-induced apoptosis in primary medulloblastoma samples, and cooperates with Doxorubicin to suppress medulloblastoma growth in an in vivo model, which underscores the clinical relevance of the findings. Thus, HDACI such as MS-275 present a promising approach for chemosensitization of medulloblastoma by enhancing mitochondrial apoptosis in a p53-dependent manner. These findings have important clinical implications for the design of experimental treatment protocols for medulloblastoma.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1476-5594
pubmed:author
pubmed:issnType
Electronic
pubmed:day
12
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2275-81
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Histone deacetylase inhibitors prime medulloblastoma cells for chemotherapy-induced apoptosis by enhancing p53-dependent Bax activation.
pubmed:affiliation
University Children's Hospital, Ulm, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't