p53 Is a Master Regulator of Proteostasis in SMARCB1-Deficient Malignant Rhabdoid Tumors

Cancer Cell. 2019 Feb 11;35(2):204-220.e9. doi: 10.1016/j.ccell.2019.01.006.

Abstract

Alterations in chromatin remodeling genes have been increasingly implicated in human oncogenesis. Specifically, the biallelic inactivation of the SWI/SNF subunit SMARCB1 results in the emergence of extremely aggressive pediatric malignancies. Here, we developed embryonic mosaic mouse models of malignant rhabdoid tumors (MRTs) that faithfully recapitulate the clinical-pathological features of the human disease. We demonstrated that SMARCB1-deficient malignancies exhibit dramatic activation of the unfolded protein response (UPR) and ER stress response via a genetically intact MYC-p19ARF-p53 axis. As a consequence, these tumors display an exquisite sensitivity to agents inducing proteotoxic stress and inhibition of the autophagic machinery. In conclusion, our findings provide a rationale for drug repositioning trials investigating combinations of agents targeting the UPR and autophagy in SMARCB1-deficient MRTs.

Keywords: BIRC5; ER stress; MYC; SMARCB1; autophagy; embryonic mosaic GEM models; p53; proteasome inhibitors; renal medullary carcinoma; rhabdoid tumors.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Antineoplastic Agents / pharmacology
  • Autophagy* / drug effects
  • Cell Line, Tumor
  • Cyclin-Dependent Kinase Inhibitor p16 / genetics
  • Cyclin-Dependent Kinase Inhibitor p16 / metabolism
  • Endoplasmic Reticulum Stress* / drug effects
  • Female
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Male
  • Mice, 129 Strain
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Proteasome Inhibitors / pharmacology
  • Proteostasis* / drug effects
  • Proto-Oncogene Proteins c-myc / genetics
  • Proto-Oncogene Proteins c-myc / metabolism
  • Rhabdoid Tumor / drug therapy
  • Rhabdoid Tumor / genetics
  • Rhabdoid Tumor / metabolism*
  • Rhabdoid Tumor / pathology
  • SMARCB1 Protein / deficiency*
  • SMARCB1 Protein / genetics
  • Signal Transduction
  • Tumor Cells, Cultured
  • Tumor Suppressor Protein p53 / deficiency
  • Tumor Suppressor Protein p53 / genetics
  • Tumor Suppressor Protein p53 / metabolism*
  • Unfolded Protein Response

Substances

  • Antineoplastic Agents
  • Cdkn2a protein, mouse
  • Cyclin-Dependent Kinase Inhibitor p16
  • Myc protein, mouse
  • Proteasome Inhibitors
  • Proto-Oncogene Proteins c-myc
  • SMARCB1 Protein
  • SMARCB1 protein, human
  • Smarcb1 protein, mouse
  • TP53 protein, human
  • Trp53 protein, mouse
  • Tumor Suppressor Protein p53