title: IkappaB kinase beta inhibition induces cell death in Imatinib-resistant and T315I Dasatinib-resistant BCR-ABL+ cells.
abstract: Chronic myelogenous leukemia is a malignant disease of the hematopoietic stem cell compartment, which is characterized by expression of the BCR-ABL fusion protein. Expression of BCR-ABL allows myeloid cells to grow in the absence of the growth factors interleukin-3 and granulocyte-macrophage colony-stimulating factor. The tyrosine kinase activity of BCR-ABL constitutively activates signaling pathways associated with Ras and its downstream effectors and with the Jak/STAT pathway. Additionally, we reported previously that BCR-ABL activates the transcription factor nuclear factor-kappaB (NF-kappaB) in a manner dependent on Ras and that inhibition of NF-kappaB by expression of a modified form of IkappaBalpha blocked BCR-ABL-driven tumor growth in a xenograft model. Here, we show that a highly specific inhibitor of IkappaB kinase beta, a key upstream regulator of the NF-kappaB pathway, induces growth suppression and death in cells expressing wild-type, Imatinib-resistant, or the T315I Imatinib/Dasatinib-resistant forms of BCR-ABL. Cell cycle variables were not affected by this compound. These data indicate that blockage of BCR-ABL-induced NF-kappaB activation via IkappaB kinase beta inhibition represents a potential new approach for treatment of Imatinib- or Dasatinib-resistant forms of chronic myelogenous leukemia.
authors.affiliation: Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC 27599-7295, USA.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Duncan
authors.forename: Christine A
authors.initials: CA
authors.lastname: Goetz
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Stein
authors.forename: Katie J
authors.initials: KJ
authors.lastname: Mayo
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Skaggs
authors.forename: Karl
authors.initials: K
authors.lastname: Ziegelbauer
authors.forename: Charles L
authors.initials: CL
authors.lastname: Sawyers
authors.forename: Albert S
authors.initials: AS
authors.lastname: Baldwin
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D001549:Benzamides; D002453:Cell Cycle / Q000187:drug effects; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D000069439:Dasatinib; D004353:Drug Evaluation, Preclinical; D019008:Drug Resistance, Neoplasm / Q000187:drug effects; D016313:Genes, abl; D006801:Humans; D051550:I-kappa B Kinase / Q000037:antagonists & inhibitors* / Q000378:metabolism / Q000502:physiology; D000068877:Imatinib Mesylate; D010766:Phosphorylation / Q000187:drug effects; D010879:Piperazines / Q000494:pharmacology*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011743:Pyrimidines / Q000494:pharmacology*; D013844:Thiazoles / Q000494:pharmacology*; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D013844:Thiazoles; D000068877:Imatinib Mesylate; D051550:I-kappa B Kinase; D000069439:Dasatinib