Proteasome inhibitors potentiate leukemic cell apoptosis induced by the cyclin-dependent kinase inhibitor flavopiridol through a SAPK/JNK- and NF-κB-dependent process

被引:119
作者
Dai, Y
Rahmani, M
Grant, S
机构
[1] Virginia Commonwealth Univ, Med Coll Virginia, Div Hematol Oncol, Dept Med, Richmond, VA 23298 USA
[2] Virginia Commonwealth Univ, Med Coll Virginia, Dept Pharmacol, Richmond, VA 23298 USA
[3] Virginia Commonwealth Univ, Med Coll Virginia, Dept Biochem & Mol Biophys, Richmond, VA 23298 USA
关键词
apoptosis; proteasome inhibitor; flavopiridol; NF-kappa B; JNK;
D O I
10.1038/sj.onc.1206863
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Interactions between proteasome and cyclin-dependent kinase inhibitors have been examined in human leukemia cells in relation to induction of apoptosis. Simultaneous exposure (24 h) of U937 myelomonocytic leukemia cells to 100 nm flavopiridol and 300 nm MG-132 resulted in a marked increase in mitochondrial injury ( cytochrome c, Smac/DIABLO release, loss of DeltaPsim), caspase activation, and synergistic induction of cell death, accompanied by a marked decrease in clonogenic potential. Similar effects were observed with other proteasome inhibitors (e. g., Bortezomib (VELCADE(TM) bortezomib or injection), lactacystin, LLnL) and cyclin-dependent kinase inhibitors (e. g., roscovitine), as well as other leukemia cell types (e.g., HL-60, Jurkat, Raji). In U937 cells, synergistic interactions between MG-132 and. avopiridol were associated with multiple perturbations in expression/activation of signaling- and survival-related proteins, including downregulation of XIAP and Mcl-1, activation of JNK and p34(cdc2), and diminished expression of p21(CIP1). The lethal effects of MG-132/flavopiridol were not reduced in leukemic cells ectopically expressing Bcl-2, but were partially attenuated in cells ectopically expressing dominant-negative caspase-8 or CrmA. Flavopiridol/proteasome inhibitor-mediated lethality was also significantly diminished by agents and siRNA blocking JNK activation. Lastly, coadministration of MG-132 with. avopiridol resulted in diminished DNA binding of NF-kappaB. Notably, pharmacologic interruption of the NF-kappaB pathway (e. g., by BAY 11-7082, PDTC, or SN-50) or molecular dysregulation of NF-kappaB (i.e., in cells ectopically expressing an IkappaBalpha super-repressor) mimicked the actions of proteasome inhibitors in promoting flavopiridol-induced mitochondrial injury, JNK activation, and apoptosis. Together, these findings indicate that proteasome inhibitors strikingly lower the apoptotic threshold of leukemic cells exposed to pharmacologic CDK inhibitors, and suggest that interruption of the NF-kappaB cytoprotective pathway and JNK activation both play key roles in this phenomenon. They also raise the possibility that combining proteasome and CDK inhibitors could represent a novel antileukemic strategy.
引用
收藏
页码:7108 / 7122
页数:15
相关论文
共 66 条
[41]  
Ogiso Y, 2000, CANCER RES, V60, P2429
[42]   Phase I trial of the proteasome inhibitor PS-341 in patients with refractory hematologic malignancies [J].
Orlowski, RZ ;
Stinchcombe, TE ;
Mitchell, BS ;
Shea, TC ;
Baldwin, AS ;
Stahl, S ;
Adams, J ;
Esseltine, DL ;
Elliott, PJ ;
Pien, CS ;
Guerciolini, R ;
Anderson, JK ;
Depcik-Smith, ND ;
Bhagat, R ;
Lehman, MJ ;
Novick, SC ;
O'Connor, OA ;
Soignet, SL .
JOURNAL OF CLINICAL ONCOLOGY, 2002, 20 (22) :4420-4427
[43]   Early induction of apoptosis in hematopoietic cell lines after exposure to flavopiridol [J].
Parker, BW ;
Kaur, G ;
Nieves-Neira, W ;
Taimi, M ;
Kohlhagen, G ;
Shimizu, T ;
Losiewicz, MD ;
Pommier, Y ;
Sausville, EA ;
Senderowicz, AM .
BLOOD, 1998, 91 (02) :458-465
[44]   Proteasome inhibitors induce cerebellar granule cell death -: Inhibition of nuclear factor-κB activation [J].
Porcile, C ;
Piccioli, P ;
Stanzione, S ;
Bajetto, A ;
Bonavia, R ;
Barbero, S ;
Florio, T ;
Schettini, G .
CELL SIGNALING, TRANSCRIPTION, AND TRANSLATION AS THERAPEUTIC TARGETS, 2002, 973 :402-413
[45]   Functional cooperation between JunD and NF-κB in rat hepatocytes [J].
Rahmani, M ;
Péron, P ;
Weitzman, J ;
Bakiri, L ;
Lardeux, B ;
Bernuau, D .
ONCOGENE, 2001, 20 (37) :5132-5142
[46]  
Rosato RR, 2002, MOL CANCER THER, V1, P253
[47]   Role of NF-κB in p53-mediated programmed cell death [J].
Ryan, KM ;
Ernst, MK ;
Rice, NR ;
Vousden, KH .
NATURE, 2000, 404 (6780) :892-897
[48]   Molecular aspects of the mammalian cell cycle and cancer [J].
Sandal, T .
ONCOLOGIST, 2002, 7 (01) :73-81
[49]   Mechanisms of action of flavopiridol [J].
Sedlacek, HH .
CRITICAL REVIEWS IN ONCOLOGY HEMATOLOGY, 2001, 38 (02) :139-170
[50]   Flavopiridol: the first cyclin-dependent kinase inhibitor in human clinical trials [J].
Senderowicz, AM .
INVESTIGATIONAL NEW DRUGS, 1999, 17 (03) :313-320