Mutated and non-mutated TP53 as targets in the treatment of leukaemia

Br J Haematol. 2008 May;141(4):445-53. doi: 10.1111/j.1365-2141.2008.07046.x. Epub 2008 Mar 12.

Abstract

TP53 is mutated in 10-20% of cases of chronic lymphocytic leukaemia (CLL) and 3-8% of cases of acute myeloid leukaemia (AML). Recently, two classes of compounds that restore the function of p53 in tumours have been described. PRIMA-1 (p53-dependent reactivation and induction of massive apoptosis) restores the wild-type conformation of mutant TP53, whereas RITA (reactivation of p53 and induction of tumour cell apoptosis) increases intracellular levels of p53. We evaluated the effects of RITA alone and in combination with PRIMA-1 or conventional cytostatics on leukaemic cells isolated from AML and CLL patients. AML samples with -17, which are more resistant to daunorubicin and cytarabine compared with samples without -17, were effectively killed by PRIMA-1. RITA, which stabilizes the function of wild-type p53, induced apoptosis in AML cells. In contrast to that seen with PRIMA-1, AML patient samples without -17 were significantly more sensitive to RITA. Similarly, RITA exerted dose-dependent apoptosis and cytotoxicity in CLL cells, which was significantly more pronounced in samples without hemizygous TP53 deletion. Notably, a synergistic effect was observed in all CLL samples with RITA and fludarabine in combination. In both AML and CLL cells exposure to RITA resulted in induction of intracellular p53. We conclude that small molecules targeting p53 might be of clinical importance in the future for treating drug-resistant leukaemia.

MeSH terms

  • Antineoplastic Agents / pharmacology
  • Apoptosis / drug effects
  • Cell Cycle / drug effects
  • Cell Death / drug effects
  • Chromosome Aberrations
  • Cytarabine / pharmacology
  • Daunorubicin / pharmacology
  • Dose-Response Relationship, Drug
  • Drug Synergism
  • Furans / pharmacology
  • Genes, p53 / genetics*
  • Humans
  • Leukemia, Lymphocytic, Chronic, B-Cell / genetics*
  • Leukemia, Lymphocytic, Chronic, B-Cell / metabolism
  • Leukemia, Lymphocytic, Chronic, B-Cell / pathology
  • Leukemia, Myeloid, Acute / genetics*
  • Leukemia, Myeloid, Acute / metabolism
  • Leukemia, Myeloid, Acute / pathology
  • Membrane Proteins / pharmacology
  • Mutation*
  • Nerve Tissue Proteins / pharmacology
  • Tumor Cells, Cultured
  • Tumor Suppressor Protein p53 / metabolism
  • Vidarabine / analogs & derivatives
  • Vidarabine / pharmacology

Substances

  • Antineoplastic Agents
  • Furans
  • Membrane Proteins
  • NSC 652287
  • Nerve Tissue Proteins
  • PRIMA1 protein, human
  • Tumor Suppressor Protein p53
  • Cytarabine
  • Vidarabine
  • fludarabine
  • Daunorubicin