Combining the FLT3 inhibitor PKC412 and the triterpenoid CDDO-Me synergistically induces apoptosis in acute myeloid leukemia with the internal tandem duplication mutation.
Mutations of the FLT3 receptor tyrosine kinase consisting of internal tandem duplications (ITD) have been detected in blasts from 20% to 30% of patients with acute myeloid leukemia (AML) and are associated with a poor prognosis. FLT3/ITD results in constitutive autophosphorylation of the receptor and factor-independent survival in leukemia cell lines. The C-28 methyl ester of the oleane triterpenoid (CDDO-Me) is a multifunctional molecule that induces apoptosis of human myeloid leukemia cells. Here, we report that CDDO-Me blocks targeting of NFkappaB to the nucleus by inhibiting IkappaB kinase beta-mediated phosphorylation of IkappaBalpha. Moreover, CDDO-Me blocked constitutive activation of the signal transducer and activator of transcription 3. We report the potent and selective antiproliferative effects of CDDO-Me on FLT3/ITD-positive myeloid leukemia cell lines and primary AML cells. The present studies show that CDDO-Me treatment results in caspase-3-mediated induction of apoptosis of FLT3/ITD-expressing cells and its antiproliferative effects are synergistic with PKC412, a FLT3-tyrosine kinase inhibitor currently in clinical trials. Taken together, our studies indicate that CDDO-Me greatly enhanced the efficacy of the FLT3 inhibitor PKC412, suggesting that combining two separate pathway inhibitors might be a viable therapeutic strategy for AML associated with a FLT3/ITD mutation.
Ahmad
Rehan
R
Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115, USA.
Liu
Suiyang
S
Weisberg
Ellen
E
Nelson
Erik
E
Galinsky
Ilene
I
Meyer
Colin
C
Kufe
Donald
D
Kharbanda
Surender
S
Stone
Richard
R
D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D048708:Cell Growth Processes / Q000187:drug effects / Q000235:genetics; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D004357:Drug Synergism; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D008297:Male; D051379:Mice; D009154:Mutation; D009828:Oleanolic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D010766:Phosphorylation; D015398:Signal Transduction; D019311:Staurosporine / Q000031:analogs & derivatives* / Q000494:pharmacology; D051941:fms-Like Tyrosine Kinase 3 / Q000037:antagonists & inhibitors* / Q000235:genetics
D009828:Oleanolic Acid; C445068:bardoxolone methyl; C497970:FLT3 protein, human; D051941:fms-Like Tyrosine Kinase 3; D053148:Caspase 3; D019311:Staurosporine; C059539:midostaurin