PCI-24781 induces caspase and reactive oxygen species-dependent apoptosis through NF-kappaB mechanisms and is synergistic with bortezomib in lymphoma cells.
PCI-24781 induces caspase and reactive oxygen species-dependent apoptosis through NF-kappaB mechanisms and is synergistic with bortezomib in lymphoma cells.
复制标题
DOI：
10.1158/1078-0432.ccr-08-2365
复制
发表时间：
2009-05-15
期刊：
影响因子：
--
通讯作者：
Evens AM
中科院分区：
文献类型：
--
作者：
Bhalla S;Balasubramanian S;David K;Sirisawad M;Buggy J;Mauro L;Prachand S;Miller R;Gordon LI;Evens AM
We investigated the cytotoxicity and mechanisms of cell death of the broad-spectrum histone deacetylase inhibitor (HDACi), PCI-24781, alone and combined with bortezomib in Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) cell lines and primary lymphoproliferative (CLL/SLL) cells. Apoptosis, mitochondrial membrane potential, cell cycle analysis, and reactive oxygen species (ROS) were measured by flow cytometry, while caspase-activation was determined by Western blot. NF-kB-related mRNAs were quantified by RT-PCR, NF-kB-related proteins by Western blotting, and NF-kB DNA binding-activity by electromobility shift assay. Finally, gene expression profiling (GEP) was analyzed. PCI-24781 induced concentration-dependent apoptosis that was associated with prominent G0/G1 arrest, decreased S-phase, increased p21 protein, and increased ROS in HL and NHL cell lines. Dose-dependent apoptosis with PCI-24781 was also seen among primary CLL/SLL cells. PCI-24781-induced apoptosis was shown to be ROS- and caspase-dependent. Combined PCI-24781/bortezomib treatment resulted in strong synergistic apoptosis in all NHL lines (combination indices: 0.19-0.6) and was additive in HL and primary CLL/SLL cells. Further, PCI-24781/bortezomib resulted in increased caspase cleavage, mitochondrial depolarization, and histone acetylation vs either agent alone. GEP showed that PCI-24781-alone significantly downregulated several antioxidant genes, proteasome components, and NF-kB pathway genes, effects which were enhanced further with bortezomib. RT-PCR confirmed downregulation of NF-kB1 (p105), c-Myc, and IkB-kinase subunits, while NF-kB DNA-binding activity was decreased. We show that PCI-24781 results in increased ROS and NF-kB inhibition, leading to caspase-dependent apoptosis. We also demonstrate that bortezomib is synergistic with PCI-24781. This combination or PCI-24781 alone has potential therapeutic value in lymphoma.
