TIC10/ONC201 synergizes with Bcl-2/Bcl-xL inhibition in glioblastoma by suppression of Mcl-1 and its binding partners in vitro and in vivo

Oncotarget. 2015 Nov 3;6(34):36456-71. doi: 10.18632/oncotarget.5505.


Glioblastoma is the most frequent primary brain tumor in adults. Current therapeutic options are sparse and the prognosis of patients suffering from this disease is grim. Abundance in intratumoral heterogeneity among different deregulated signaling pathways is a hallmark of glioblastoma and likely accounts for its recurrence and resistance to treatment. Glioblastomas harbor a plethora of deregulated pathways driving tumor formation and growth. In this study, we show that TIC10/ONC201, a promising compound that is currently in planned clinical development, along with Bcl-2/Bcl-xL inhibition by ABT263 yields a strong synergistic antiproliferative effect on pediatric, adult, proneural glioblastoma and glioma stem-like cells. On the molecular level, treatment with TIC10/ONC201 results in a posttranslational decrease of the anti-apoptotic Bcl-2 family member, myeloid cell leukemia 1 (Mcl-1), through modulation of the chaperone Bag3 and the deubiquitinase Usp9X. Consistently, the combination treatment of TIC10/ONC201 and ABT263 required the presence of functional BAX and BAK to drive intrinsic apoptosis, but is surprisingly independent of the extrinsic apoptotic pathway. Moreover, the expression of Noxa protein was required for efficient apoptosis induction by TIC10/ONC201 and ABT263. Importantly, the drug combination of TIC10/ONC201 and the BH3-mimetic, ABT263, led to a regression of tumors in vivo, without any notable toxicity and side effects. Overall, TIC10/ONC201 along with Bcl-2/Bcl-xL inhibition holds significant promise as a novel potential approach for the treatment of recalcitrant tumors such as glioblastoma.

Keywords: ABT263; TIC10/ONC201; apoptotic resistance; glioblastoma; multi-targeting.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aniline Compounds / administration & dosage
  • Aniline Compounds / pharmacology*
  • Animals
  • Antineoplastic Combined Chemotherapy Protocols / pharmacology*
  • Apoptosis / drug effects
  • Brain Neoplasms / drug therapy*
  • Brain Neoplasms / metabolism
  • Brain Neoplasms / pathology
  • Drug Synergism
  • Female
  • Glioblastoma / drug therapy*
  • Glioblastoma / metabolism
  • Glioblastoma / pathology
  • Heterocyclic Compounds, 4 or More Rings / administration & dosage
  • Heterocyclic Compounds, 4 or More Rings / pharmacology*
  • Humans
  • Imidazoles
  • MAP Kinase Signaling System / drug effects
  • Male
  • Mice
  • Mice, SCID
  • Myeloid Cell Leukemia Sequence 1 Protein / antagonists & inhibitors*
  • Myeloid Cell Leukemia Sequence 1 Protein / metabolism
  • Proto-Oncogene Proteins c-bcl-2 / antagonists & inhibitors*
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • Pyridines
  • Pyrimidines
  • Random Allocation
  • Sulfonamides / administration & dosage
  • Sulfonamides / pharmacology*
  • Xenograft Model Antitumor Assays
  • bcl-X Protein / antagonists & inhibitors*
  • bcl-X Protein / metabolism


  • Aniline Compounds
  • BCL2L1 protein, human
  • Heterocyclic Compounds, 4 or More Rings
  • Imidazoles
  • MCL1 protein, human
  • Myeloid Cell Leukemia Sequence 1 Protein
  • Proto-Oncogene Proteins c-bcl-2
  • Pyridines
  • Pyrimidines
  • Sulfonamides
  • bcl-X Protein
  • TIC10 compound
  • navitoclax