Histone deacetylase inhibitor LAQ824 both lowers expression and promotes proteasomal degradation of Bcr-Abl and induces apoptosis of imatinib mesylate-sensitive or -refractory chronic myelogenous leukemia-blast crisis cells

Cancer Res. 2003 Aug 15;63(16):5126-35.

Abstract

Treatment with LAQ824 (Novartis Pharmaceutical, Inc.), a cinnamyl hydroxamic acid analogue inhibitor of histone deacetylases, depleted the mRNA and protein expression of Bcr-Abl in human chronic myeloid leukemia blast crisis (CML-BC) cells. Exposure to LAQ824 induced the expression of the cell cycle-dependent kinase inhibitors p21 and p27 and caused cell cycle G(1)-phase accumulation and apoptosis of CML-BC cells. LAQ824 also induced acetylation of heat shock protein 90. This inhibited the chaperone association of Bcr-Abl with heat shock protein 90, thereby promoting the proteasomal degradation of Bcr-Abl. Cotreatment with LAQ824 increased imatinib mesylate-induced apoptosis of CML-BC cells. Additionally, LAQ824 down-regulated the levels of mutant Bcr-Abl possessing the T315I point mutation, as well as induced apoptosis of imatinib-refractory primary CML-BC cells. Therefore, LAQ824 may be a promising therapeutic agent in the treatment of imatinib-sensitive or -refractory human leukemia.

MeSH terms

  • Acetylation
  • Antineoplastic Agents / pharmacology*
  • Apoptosis / drug effects*
  • Benzamides
  • Blast Crisis / drug therapy*
  • Cyclin-Dependent Kinase Inhibitor p21
  • Cyclins / biosynthesis
  • Cysteine Endopeptidases / physiology*
  • Drug Resistance, Neoplasm
  • Enzyme Inhibitors / pharmacology*
  • Fusion Proteins, bcr-abl / genetics
  • Fusion Proteins, bcr-abl / metabolism*
  • G1 Phase / drug effects
  • Histone Deacetylase Inhibitors*
  • Humans
  • Hydroxamic Acids / pharmacology*
  • Imatinib Mesylate
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / drug therapy*
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / metabolism
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / pathology
  • Microfilament Proteins / biosynthesis
  • Multienzyme Complexes / physiology*
  • Muscle Proteins*
  • Piperazines / pharmacology*
  • Promoter Regions, Genetic
  • Proteasome Endopeptidase Complex
  • Pyridones / pharmacology
  • Pyrimidines / pharmacology*
  • Tumor Cells, Cultured

Substances

  • Antineoplastic Agents
  • Benzamides
  • CDKN1A protein, human
  • Cyclin-Dependent Kinase Inhibitor p21
  • Cyclins
  • Enzyme Inhibitors
  • Histone Deacetylase Inhibitors
  • Hydroxamic Acids
  • LAQ824
  • Microfilament Proteins
  • Multienzyme Complexes
  • Muscle Proteins
  • Piperazines
  • Pyridones
  • Pyrimidines
  • Tagln protein, mouse
  • Imatinib Mesylate
  • Fusion Proteins, bcr-abl
  • Cysteine Endopeptidases
  • Proteasome Endopeptidase Complex
  • PD 180970