ID 113049
著者
Bat-Erdene, Ariunzaya Tokushima University
Oda, Asuka Tokushima University
天知, 良太 Tokushima University
Iwasa, Masami Tokushima University
キーワード
multiple myeloma
panobinostat
proteasome inhibitors
caspase-8
Sp1
資料タイプ
学術雑誌論文
抄録
Panobinostat, a pan-deacetylase inhibitor, synergistically elicits cytotoxic activity against myeloma (MM) cells in combination with the proteasome inhibitor bortezomib. Because precise mechanisms for panobinostat’s anti-MM action still remain elusive, we aimed to clarify the mechanisms of anti-MM effects of panobinostat and its synergism with proteasome inhibitors. Although the transcription factor Sp1 was overexpressed in MM cells, the Sp1 inhibitor terameprocol induced MM cell death in parallel with reduction of IRF4 and cMyc. Panobinostat induced activation of caspase-8, which was inversely correlated with reduction of Sp1 protein levels in MM cells. The panobinostat-mediated effects were further potentiated to effectively induce MM cell death in combination with bortezomib or carfilzomib even at suboptimal concentrations as a single agent. Addition of the caspase-8 inhibitor z-IETD-FMK abolished the Sp1 reduction not only by panobinostat alone but also by its combination with bortezomib, suggesting caspase-8-mediated Sp1 degradation. The synergistic Sp1 reduction markedly suppressed Sp1-driven prosurvival factors, IRF4 and cMyc. Besides, the combinatory treatment reduced HDAC1, another Sp1 target, in MM cells, which may potentiate HDAC inhibition. Collectively, caspase-8-mediated post-translational Sp1 degradation appears to be among major mechanisms for synergistic anti-MM effects of panobinostat and proteasome inhibitors in combination.
掲載誌名
Oncotarget
ISSN
19492553
出版者
Impact Journals, LLC
7
48
開始ページ
79064
終了ページ
79075
発行日
2016-10-12
備考
This is an open-access article distributed under the terms of the Creative Commons Attribution License 3.0 (CC BY 3.0)(https://creativecommons.org/licenses/by/3.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
EDB ID
出版社版DOI
出版社版URL
フルテキストファイル
言語
eng
著者版フラグ
出版社版
部局
病院
医学系
歯学系