TY - JOUR
T1 - Interruption of the NF-κB pathway by Bay 11-7082 promotes UCN-01-mediated mitochondrial dysfunction and apoptosis in human multiple myeloma cells
AU - Dai, Yun
AU - Pei, Xin Yan
AU - Rahmani, Mohamed
AU - Conrad, Daniel H.
AU - Dent, Paul
AU - Grant, Steven
PY - 2004/4/1
Y1 - 2004/4/1
N2 - Interactions between pharmacologic NF-κB inhibitors (eg, Bay 11-7082, SN-50) and the checkpoint abrogator UCN-01 have been examined in human multiple myeloma (MM) cells. Exposure of U266 cells to Bay 11-7082 (Bay) in combination with UCN-01 resulted in the abrogation of NF-κB/DNA binding activity and the synergistic induction of apoptosis. Comparable synergism was observed in other MM cell lines and patient-derived CD138+ cells and between an inhibitory peptide of NF-κB (SN50) and UCN-01. Bay/UCN-01-mediated lethality involved mitochondrial dysfunction, caspase cleavage, and poly adenosine diphosphate-ribose polymerase (PARP) degradation. Although Bay modestly blocked UCN-01-induced extracellular signal-regulated kinase (ERK) phosphorylation, coadministration activated c-Jun N-terminal kinase (JNK) and cdc2/cdk1 and down-regulated Mcl-1, XIAP, and Bcl-X L. Transfection with a constitutively activated mitogen-activated protein kinase kinase (MEK1)/green fluorescent protein (GFP) construct failed to block apoptosis induced by Bay/UCN-01 but significantly attenuated MEK inhibitor (U0126)/UCN-01-induced lethality. Inhibiting JNK activation with SP600125 or D-JNK11 peptide markedly reduced Bay/UCN-01-mediated mitochondrial dysfunction and apoptosis and the down-regulation of Mcl-1, XIAP, and Bcl-X L but not of cdc2/cdk1 activation. Stable transfection of cells with dominant-negative caspase-9 dramatically diminished Bay/UCN-01 lethality without altering JNK of cdc2/cdk1 activation. Neither interleukin-6 (IL-6)-nor fibronectin-mediated adherence conferred resistance to Bay/UCN-01-induced apoptosis. Together, these findings suggest that a strategy combining UCN-01 with disruption of the IκB kinase (IKK)/IκB/NF-κB pathway warrants attention in MM.
AB - Interactions between pharmacologic NF-κB inhibitors (eg, Bay 11-7082, SN-50) and the checkpoint abrogator UCN-01 have been examined in human multiple myeloma (MM) cells. Exposure of U266 cells to Bay 11-7082 (Bay) in combination with UCN-01 resulted in the abrogation of NF-κB/DNA binding activity and the synergistic induction of apoptosis. Comparable synergism was observed in other MM cell lines and patient-derived CD138+ cells and between an inhibitory peptide of NF-κB (SN50) and UCN-01. Bay/UCN-01-mediated lethality involved mitochondrial dysfunction, caspase cleavage, and poly adenosine diphosphate-ribose polymerase (PARP) degradation. Although Bay modestly blocked UCN-01-induced extracellular signal-regulated kinase (ERK) phosphorylation, coadministration activated c-Jun N-terminal kinase (JNK) and cdc2/cdk1 and down-regulated Mcl-1, XIAP, and Bcl-X L. Transfection with a constitutively activated mitogen-activated protein kinase kinase (MEK1)/green fluorescent protein (GFP) construct failed to block apoptosis induced by Bay/UCN-01 but significantly attenuated MEK inhibitor (U0126)/UCN-01-induced lethality. Inhibiting JNK activation with SP600125 or D-JNK11 peptide markedly reduced Bay/UCN-01-mediated mitochondrial dysfunction and apoptosis and the down-regulation of Mcl-1, XIAP, and Bcl-X L but not of cdc2/cdk1 activation. Stable transfection of cells with dominant-negative caspase-9 dramatically diminished Bay/UCN-01 lethality without altering JNK of cdc2/cdk1 activation. Neither interleukin-6 (IL-6)-nor fibronectin-mediated adherence conferred resistance to Bay/UCN-01-induced apoptosis. Together, these findings suggest that a strategy combining UCN-01 with disruption of the IκB kinase (IKK)/IκB/NF-κB pathway warrants attention in MM.
UR - http://www.scopus.com/inward/record.url?scp=1642278407&partnerID=8YFLogxK
U2 - 10.1182/blood-2003-09-3037
DO - 10.1182/blood-2003-09-3037
M3 - Article
C2 - 14645003
AN - SCOPUS:1642278407
SN - 0006-4971
VL - 103
SP - 2761
EP - 2770
JO - Blood
JF - Blood
IS - 7
ER -