title: Dual inhibition of Bcr-Abl and Hsp90 by C086 potently inhibits the proliferation of imatinib-resistant CML cells.
abstract: OBJECTIVE
  Although tyrosine kinase inhibitors (TKI) such as imatinib provide an effective treatment against Bcr-Abl kinase activity in the mature cells of patients with chronic myelogenous leukemia (CML), TKIs probably cannot eradicate the leukemia stem cell (LSC) population. Therefore, alternative therapies are required to target both mature CML cells with wild-type (WT) or mutant Bcr-Abl and LSCs. To investigate the effect of C086, a derivative of curcumin, on imatinib-resistant cells, we explored its underlying mechanisms of Bcr-Abl kinase and heat shock protein 90 (Hsp90) function inhibition.
  
  
  METHODS
  Biochemical assays were used to test ABL kinase activity; fluorescence measurements using recombinant NHsp90, Hsp90 ATPase assay, immunoprecipitation, and immunoblotting were applied to examine Hsp90 function. Colony-forming unit, long-term culture-initiating cells (LTC-IC), and flow cytometry were used to test CML progenitor and stem cells.
  
  
  RESULTS
  Biochemical assays with purified recombinant Abl kinase confirmed that C086 can directly inhibit the kinase activity of Abl, including WT and the Q252H, Y253F, and T315I mutations. Furthermore, we identified C086 as a novel Hsp90 inhibitor with the capacity to disrupt the Hsp90 chaperone function in CML cells. Consequently, it inhibited the growth of both imatinib-sensitive and -resistant CML cells. Interestingly, C086 has the capacity to inhibit LTC-ICs and to induce apoptosis in both CD34(+)CD38(+) and CD34(+)CD38(-) cells in vitro. Moreover, C086 could decrease the number of CD45(+), CD45(+)CD34(+)CD38(+), and CD45(+)CD34(+)CD38(-) cells in CML NOD-SCID mice.
  
  
  CONCLUSIONS
  Dual suppression of Abl kinase activity and Hsp90 chaperone function by C086 provides a new therapeutic strategy for treating Bcr-Abl-induced leukemia resistant to TKIs.
authors.affiliation: Department of Pharmacology, School of Pharmacy, Fujian Medical University (FMU), Fuzhou, P.R. China. Institute of Materia Medica, Fujian Medical University (FMU), Fuzhou, P.R. China. Fuijan Key Laboratory of Natural Medicine Pharmacology, Fujian Medical University (FMU), Fuzhou, P. R. China. wlx-lisa@126.com chenyz@mail.fjmu.edu.cn xjh@mail.fjmu.edu.cn.
authors.forename: Lixian
authors.initials: L
authors.lastname: Wu
authors.affiliation: Department of Pathology, School of Basic Medicine, Fujian Medical University (FMU), Fuzhou, P.R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yu
authors.affiliation: Department of Pharmacology, School of Pharmacy, Fujian Medical University (FMU), Fuzhou, P.R. China. Institute of Materia Medica, Fujian Medical University (FMU), Fuzhou, P.R. China.
authors.forename: Ruijia
authors.initials: R
authors.lastname: Chen
authors.affiliation: Institute of Materia Medica, Fujian Medical University (FMU), Fuzhou, P.R. China. Fuijan Key Laboratory of Natural Medicine Pharmacology, Fujian Medical University (FMU), Fuzhou, P. R. China. Department of Pharmacochemistry, School of Pharmacy, Fujian Medical University (FMU), Fuzhou, P.R. China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Shanghai Institute of Materia Medica, P.R. China.
authors.forename: Liguang
authors.initials: L
authors.lastname: Lou
authors.affiliation: Institute of Materia Medica, Fujian Medical University (FMU), Fuzhou, P.R. China. Fuijan Key Laboratory of Natural Medicine Pharmacology, Fujian Medical University (FMU), Fuzhou, P. R. China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Pharmacology, School of Pharmacy, Fujian Medical University (FMU), Fuzhou, P.R. China.
authors.forename: Lisen
authors.initials: L
authors.lastname: Huang
authors.affiliation: Institute of Materia Medica, Fujian Medical University (FMU), Fuzhou, P.R. China.
authors.forename: Yingjuan
authors.initials: Y
authors.lastname: Fan
authors.affiliation: Department of Pharmacology, School of Pharmacy, Fujian Medical University (FMU), Fuzhou, P.R. China.
authors.forename: Pinzhang
authors.initials: P
authors.lastname: Gao
authors.affiliation: Fujian Institute of Hematology, Union Hospital, Fujian Medical University (FMU), Fuzhou, P. R. China.
authors.forename: Meijuan
authors.initials: M
authors.lastname: Huang
authors.affiliation: Fujian Institute of Hematology, Union Hospital, Fujian Medical University (FMU), Fuzhou, P. R. China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Fujian Institute of Hematology, Union Hospital, Fujian Medical University (FMU), Fuzhou, P. R. China. wlx-lisa@126.com chenyz@mail.fjmu.edu.cn xjh@mail.fjmu.edu.cn.
authors.forename: Yuanzhong
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Pharmacology, School of Pharmacy, Fujian Medical University (FMU), Fuzhou, P.R. China. Institute of Materia Medica, Fujian Medical University (FMU), Fuzhou, P.R. China. Fuijan Key Laboratory of Natural Medicine Pharmacology, Fujian Medical University (FMU), Fuzhou, P. R. China. wlx-lisa@126.com chenyz@mail.fjmu.edu.cn xjh@mail.fjmu.edu.cn.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Xu
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D003474:Curcumin / Q000031:analogs & derivatives / Q000494:pharmacology*; D019008:Drug Resistance, Neoplasm; D016044:Fusion Proteins, bcr-abl / Q000037:antagonists & inhibitors*; D018841:HSP90 Heat-Shock Proteins / Q000037:antagonists & inhibitors*; D006801:Humans; D000068877:Imatinib Mesylate; D015151:Immunoblotting; D047468:Immunoprecipitation; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000473:pathology*; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D014411:Neoplastic Stem Cells / Q000187:drug effects; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; D018841:HSP90 Heat-Shock Proteins; D000068877:Imatinib Mesylate; D016044:Fusion Proteins, bcr-abl; D003474:Curcumin