Synthetic Lethality of Combined Bcl-2 Inhibition and p53 Activation in AML: Mechanisms and Superior Antileukemic Efficacy

Cancer Cell. 2017 Dec 11;32(6):748-760.e6. doi: 10.1016/j.ccell.2017.11.003.


Evasion of apoptosis is a hallmark of cancer. Bcl-2 and p53 represent two important nodes in apoptosis signaling pathways. We find that concomitant p53 activation and Bcl-2 inhibition overcome apoptosis resistance and markedly prolong survival in three mouse models of resistant acute myeloid leukemia (AML). Mechanistically, p53 activation negatively regulates the Ras/Raf/MEK/ERK pathway and activates GSK3 to modulate Mcl-1 phosphorylation and promote its degradation, thus overcoming AML resistance to Bcl-2 inhibition. Moreover, Bcl-2 inhibition reciprocally overcomes apoptosis resistance to p53 activation by switching cellular response from G1 arrest to apoptosis. The efficacy, together with the mechanistic findings, reveals the potential of simultaneously targeting these two apoptosis regulators and provides a rational basis for clinical testing of this therapeutic approach.

Keywords: ABT-199; Bcl-2; G(1) arrest; MAPK; MDM2; Mcl-1; RG7388; apoptosis resistance; leukemia; p53.

MeSH terms

  • Animals
  • Antineoplastic Combined Chemotherapy Protocols / pharmacology*
  • Apoptosis / drug effects
  • Bridged Bicyclo Compounds, Heterocyclic / pharmacology
  • Cell Line, Tumor
  • Drug Resistance, Neoplasm / drug effects*
  • Female
  • Humans
  • Leukemia, Myeloid, Acute / pathology*
  • Mice
  • Mice, Inbred NOD
  • Mice, SCID
  • Proto-Oncogene Proteins c-bcl-2 / antagonists & inhibitors*
  • Pyrrolidines / pharmacology
  • Sulfonamides / pharmacology
  • Synthetic Lethal Mutations / drug effects*
  • Tumor Suppressor Protein p53 / metabolism*
  • Xenograft Model Antitumor Assays
  • para-Aminobenzoates / pharmacology


  • Bridged Bicyclo Compounds, Heterocyclic
  • Proto-Oncogene Proteins c-bcl-2
  • Pyrrolidines
  • RG7388
  • Sulfonamides
  • Tumor Suppressor Protein p53
  • para-Aminobenzoates
  • venetoclax