Synergistic activity of BET inhibitor MK-8628 and PLK inhibitor Volasertib in preclinical models of medulloblastoma


  • Y. Han
  • S. Lindner
  • Y. Bei
  • H.D. Garcia
  • N. Timme
  • K. Althoff
  • A. Odersky
  • A. Schramm
  • A. Lissat
  • A. Künkele
  • H.E. Deubzer
  • A. Eggert
  • J.H. Schulte
  • A.G. Henssen


  • Cancer Letters


  • Cancer Lett 445: 24-33


  • Medulloblastoma is the most prevalent central nervous system tumor in children. Targeted treatment approaches for patients with high-risk medulloblastoma are needed as current treatment regimens are not curative in many cases and cause significant therapy-related morbidity. Medulloblastoma harboring MYC amplification have the most aggressive clinical course and worst outcome. Targeting the BET protein BRD4 has significant anti-tumor effects in preclinical models of MYC-amplified medulloblastoma, however, in most cases these are not curative. We here assessed the therapeutic efficacy of the orally bioavailable BRD4 inhibitor, MK-8628, in preclinical models of medulloblastoma. MK-8628 showed therapeutic efficacy against in vitro and in vivo models of MYC-amplified medulloblastoma by inducing apoptotic cell death and cell cycle arrest. Gene expression analysis of cells treated with MK-8628 showed that anti-tumor effects were accompanied by significant repression of MYC transcription as well as disruption of MYC-regulated transcriptional programs. Additionally, we found that targeting of MYC protein stability through pharmacological PLK1 inhibition showed synergistic anti-medulloblastoma effects when combined with MK-8628 treatment. Thus, MK-8628 is effective against preclinical high-risk medulloblastoma models and its effects can be enhanced through simultaneous targeting of PLK1.