Synergistic induction of mitochondrial damage and apoptosis in human leukemia cells by flavopiridol and the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA)
Synergistic induction of mitochondrial damage and apoptosis in human leukemia cells by flavopiridol and the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA)
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DOI：
10.1038/sj.leu.2402535
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发表时间：
2002-07-01
期刊：
影响因子：
11.4
通讯作者：
Grant, S
中科院分区：
文献类型：
--
作者：
Almenara, J;Rosato, R;Grant, S
在人白血病细胞中检测了组蛋白去乙酰化酶抑制剂SAHA（辛二酰苯胺异羟肟酸）和细胞周期蛋白依赖性激酶（CDK）抑制剂flavopiridol（FP）之间的相互作用。将骨髓单核细胞白血病细胞（U937）同时暴露于SAHA（1 μ M）和FP（100 nM）（24 h），其单独具有最低毒性（分别为1.5+/-0.5%和16.3+/-0.5%凋亡），导致细胞死亡显著增加（即63.2+/-1.9%凋亡），通过形态学、半胱天冬酶原-3和-8切割、Bid活化、DeltaPsi（m）减少和细胞色素c释放增强反映。FP阻断SAHA介导的p21（CIP 1）和CD 11b表达上调，同时诱导caspase依赖性Bcl-2和pRb裂解。在HL-60和Jurkat白血病细胞中观察到类似的相互作用。SAHA/FP处理的细胞凋亡增强，伴随着显着减少克隆存活。显性负性caspase-8（C8-DN）或CrmA的异位表达部分减弱了SAHA/FP介导的凋亡（例如45+/-1.5%和38.2+/-2.0%凋亡vs 78+/-1.5%对照）和Bid裂解。SAHA/FP诱导的细胞凋亡不受自由基清除剂L-N-乙酰半胱氨酸或PKC抑制剂GFX的影响。最后，异位Bcl-2表达轻微减弱SAHA/FP相关的细胞凋亡/细胞色素c释放，并未能恢复暴露于这些药物的细胞中的克隆形成。总之，这些发现表明，SAHA和FP相互作用协同诱导人白血病细胞线粒体损伤和凋亡，并表明这一过程也可能涉及参与caspase-8依赖性凋亡级联反应。
Interactions between the histone deacetylase inhibitor SAHA (suberoylanilide hydroxamic acid) and the cyclin-dependent kinase (CDK) inhibitor flavopiridol (FP) were examined in human leukemia cells. Simultaneous exposure (24 h) of myelomonocytic leukemia cells (U937) to SAHA (1 muM) and FP (100 nM), which were minimally toxic alone (1.5+/-0.5% and 16.3+/-0.5% apoptosis respectively), produced a dramatic increase in cell death (ie 63.2+/-1.9% apoptotic), reflected by morphology, procaspase-3 and -8 cleavage, Bid activation, diminished DeltaPsi(m), and enhanced cytochrome c release. FP blocked SAHA-mediated up-regulation of p21(CIP1) and CD11b expression, while inducing caspase-dependent Bcl-2 and pRb cleavage. Similar interactions were observed in HL-60 and Jurkat leukemic cells. Enhanced apoptosis in SAHA/FP-treated cells was accompanied by a marked reduction in clonogenic surivival. Ectopic expression of either dominant-negative caspase-8 (C8-DN) or CrmA partially attenuated SAHA/FP-mediated apoptosis (eg 45+/-1.5% and 38.2+/-2.0% apoptotic vs 78+/-1.5% in controls) and Bid cleavage. SAHA/FP induced-apoptosis was unaffected by the free radical scavenger L-N-acetyl cysteine or the PKC inhibitor GFX. Finally, ectopic Bcl-2 expression marginally attenuated SAHA/FP-related apoptosis/cytochrome c release, and failed to restore clonogenicity in cells exposed to these agents. Together, these findings indicate that SAHA and FP interact synergistically to induce mitochondrial damage and apoptosis in human leukemia cells, and suggest that this process may also involve engagement of the caspase-8-dependent apoptotic cascade.