Putting the STING back into BH3-mimetic drugs for TP53-mutant blood cancers

Cancer Cell. 2024 May 13;42(5):850-868.e9. doi: 10.1016/j.ccell.2024.04.004. Epub 2024 Apr 25.

Abstract

TP53-mutant blood cancers remain a clinical challenge. BH3-mimetic drugs inhibit BCL-2 pro-survival proteins, inducing cancer cell apoptosis. Despite acting downstream of p53, functional p53 is required for maximal cancer cell killing by BH3-mimetics through an unknown mechanism. Here, we report p53 is activated following BH3-mimetic induced mitochondrial outer membrane permeabilization, leading to BH3-only protein induction and thereby potentiating the pro-apoptotic signal. TP53-deficient lymphomas lack this feedforward loop, providing opportunities for survival and disease relapse after BH3-mimetic treatment. The therapeutic barrier imposed by defects in TP53 can be overcome by direct activation of the cGAS/STING pathway, which promotes apoptosis of blood cancer cells through p53-independent BH3-only protein upregulation. Combining clinically relevant STING agonists with BH3-mimetic drugs efficiently kills TRP53/TP53-mutant mouse B lymphoma, human NK/T lymphoma, and acute myeloid leukemia cells. This represents a promising therapy regime that can be fast-tracked to tackle TP53-mutant blood cancers in the clinic.

Keywords: BH3-mimetic drugs; STING; acute myeloid leukemia; apoptosis; blood cancer; lymphoma; p53.

MeSH terms

  • Animals
  • Antineoplastic Agents / pharmacology
  • Antineoplastic Agents / therapeutic use
  • Apoptosis* / drug effects
  • Cell Line, Tumor
  • Hematologic Neoplasms / drug therapy
  • Hematologic Neoplasms / genetics
  • Humans
  • Membrane Proteins* / genetics
  • Mice
  • Mutation
  • Peptide Fragments / pharmacology
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins c-bcl-2 / genetics
  • Signal Transduction / drug effects
  • Tumor Suppressor Protein p53* / genetics