Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
24
pubmed:dateCreated
2005-6-15
pubmed:abstractText
We have shown that the proteasome inhibitor bortezomib (formerly known as PS-341) triggers significant antitumor activity in multiple myeloma (MM) in both preclinical models and patients with relapsed refractory disease. Recent studies have shown that unfolded and misfolded ubiquitinated proteins are degraded not only by proteasomes, but also by aggresomes, dependent on histone deacetylase 6 (HDAC6) activity. We therefore hypothesized that inhibition of both mechanisms of protein catabolism could induce accumulation of ubiquitinated proteins followed by significant cell stress and cytotoxicity in MM cells. To prove this hypothesis, we used bortezomib and tubacin to inhibit the proteasome and HDAC6, respectively. Tubacin specifically triggers acetylation of alpha-tubulin as a result of HDAC6 inhibition in a dose- and time-dependent fashion. It induces cytotoxicity in MM cells at 72 h with an IC50 of 5-20 microM, which is mediated by caspase-dependent apoptosis; no toxicity is observed in normal peripheral blood mononuclear cells. Tubacin inhibits the interaction of HDAC6 with dynein and induces marked accumulation of ubiquitinated proteins. It synergistically augments bortezomib-induced cytotoxicity by c-Jun NH2-terminal kinase/caspase activation. Importantly, this combination also induces significant cytotoxicity in plasma cells isolated from MM patient bone marrow. Finally, adherence of MM cells to bone marrow stromal cells confers growth and resistance to conventional treatments; in contrast, the combination of tubacin and bortezomib triggers toxicity even in adherent MM cells. Our studies therefore demonstrate that tubacin combined with bortezomib mediates significant anti-MM activity, providing the framework for clinical evaluation of combined therapy to improve patient outcome in MM.
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-11121744, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-11306489, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-11494147, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-11872748, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-12010457, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-12391322, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-12393500, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-12424198, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-12459731, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-12531799, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-12677000, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-12733869, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-12770821, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-12816865, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-12826635, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-12846814, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-12901942, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-14559800, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-14627979, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-14675537, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-14679006, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-14695409, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-15050914, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-15217829, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-1531068, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-15319277, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-15480425, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-15694337, http://linkedlifedata.com/resource/pubmed/commentcorrection/15937109-8260708
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Anilides, http://linkedlifedata.com/resource/pubmed/chemical/Boronic Acids, http://linkedlifedata.com/resource/pubmed/chemical/HDAC6 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Histone Deacetylase Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Histone Deacetylases, http://linkedlifedata.com/resource/pubmed/chemical/Hydroxamic Acids, http://linkedlifedata.com/resource/pubmed/chemical/Proteasome Endopeptidase Complex, http://linkedlifedata.com/resource/pubmed/chemical/Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Pyrazines, http://linkedlifedata.com/resource/pubmed/chemical/RNA, Small Interfering, http://linkedlifedata.com/resource/pubmed/chemical/Tubulin, http://linkedlifedata.com/resource/pubmed/chemical/bortezomib, http://linkedlifedata.com/resource/pubmed/chemical/tubacin
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0027-8424
pubmed:author
pubmed:issnType
Print
pubmed:day
14
pubmed:volume
102
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8567-72
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Small-molecule inhibition of proteasome and aggresome function induces synergistic antitumor activity in multiple myeloma.
pubmed:affiliation
Jerome Lipper Multiple Myeloma Center, Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, 44 Binney Street, Boston, MA 02115, USA.
pubmed:publicationType
Journal Article
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