title: Activation of the p38 Map kinase pathway is essential for the antileukemic effects of dasatinib.
abstract: Dasatinib, a dual Src/Abl tyrosine kinase inhibitor, has significant antileukemic effects against various imatinib mesylate-resistant BCR/ABL mutants. Despite well-documented inhibitory effects of dasatinib on BCR/ABL kinase, the exact downstream cellular events leading to generation of its potent antileukemic effects remain to be defined. We provide evidence that p38 Map kinase (MAPK) pathway is activated leading to increased upregulation of mixed lineage kinase 3, MKK3/6, MSK1, and Mapkapk2, upon treatment of BCR/ABL expressing cells with dasatinib, including cells expressing various imatinib-resistant mutants, except for T315I. Our data demonstrate that such dasatinib-dependent activation of p38 MAPK and its effectors plays a critical role in the generation of antileukemic responses, since pharmacological inhibition of p38 or siRNA-mediated knockdown of its expression reverse dasatinib-mediated apoptosis, cell cycle arrest, and anti-proliferative effects. p38 MAPK inhibition also reversed dasatinib-induced suppression of CML patient-derived leukemic colony-forming units progenitor growth in vitro, as well as BCR/ABL expressing KT-1 cell-derived leukemic progenitor growth. Altogether, our findings suggest a critical role for p38 MAPK pathway in the generation of antileukemic effects of dasatinib, and raise the possibility that development of novel means to enhance p38 MAPK activation in BCR/ABL expressing cells may be an approach to promote antileukemic responses and, possibly, reverse T315I mutation-mediated resistance.
authors: Dallas VAMedical Center and UT Southwestern Medical Center, Dallas, TX, USA.
authors: Disha
authors: D
authors: Dumka
authors: Poonam
authors: P
authors: Puri
authors: Nathalie
authors: N
authors: Carayol
authors: Crystal
authors: C
authors: Lumby
authors: Harikrishnan
authors: H
authors: Balachandran
authors: Katja
authors: K
authors: Schuster
authors: Amit K
authors: AK
authors: Verma
authors: Lance S
authors: LS
authors: Terada
authors: Leonidas C
authors: LC
authors: Platanias
authors: Simrit
authors: S
authors: Parmar
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D000069439:Dasatinib; D019008:Drug Resistance, Neoplasm / Q000187:drug effects / Q000235:genetics; D004789:Enzyme Activation / Q000187:drug effects; D016044:Fusion Proteins, bcr-abl / Q000235:genetics / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D020014:K562 Cells; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D048371:MAP Kinase Kinase 3 / Q000235:genetics / Q000378:metabolism; D048669:MAP Kinase Kinase 6 / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D010766:Phosphorylation / Q000187:drug effects; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D011743:Pyrimidines / Q000494:pharmacology*; D034622:RNA Interference; D038744:Ribosomal Protein S6 Kinases, 90-kDa / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D013844:Thiazoles / Q000494:pharmacology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D000099190:MAP-Kinase-Activated Kinase 2
chemical_list: D000069439:Dasatinib; D016044:Fusion Proteins, bcr-abl; D047908:Intracellular Signaling Peptides and Proteins; D048371:MAP Kinase Kinase 3; D048669:MAP Kinase Kinase 6; D047428:Protein Kinase Inhibitors; D017346:Protein Serine-Threonine Kinases; D011743:Pyrimidines; D038744:Ribosomal Protein S6 Kinases, 90-kDa; D013844:Thiazoles; D048051:p38 Mitogen-Activated Protein Kinases; D000099190:MAP-Kinase-Activated Kinase 2; C116919:mitogen and stress-activated protein kinase 1; C482566:MAP2K6 protein, human