BIM upregulation and ROS-dependent necroptosis mediate the antitumor effects of the HDACi Givinostat and Sorafenib in Hodgkin lymphoma cell line xenografts

Leukemia. 2014 Sep;28(9):1861-71. doi: 10.1038/leu.2014.81. Epub 2014 Feb 24.

Abstract

Relapsed/refractory Hodgkin's lymphoma (HL) is an unmet medical need requiring new therapeutic options. Interactions between the histone deacetylase inhibitor Givinostat and the RAF/MEK/ERK inhibitor Sorafenib were examined in HDLM-2 and L-540 HL cell lines. Exposure to Givinostat/Sorafenib induced a synergistic inhibition of cell growth (range, 70-80%) and a marked increase in cell death (up to 96%) due to increased H3 and H4 acetylation and strong mitochondrial injury. Gene expression profiling indicated that the synergistic effects of Givinostat/Sorafenib treatment are associated with the modulation of cell cycle and cell death pathways. Exposure to Givinostat/Sorafenib resulted in sustained production of reactive oxygen species (ROS) and activation of necroptotic cell death. The necroptosis inhibitor Necrostatin-1 prevented Givinostat/Sorafenib-induced ROS production, mitochondrial injury, activation of BH3-only protein BIM and cell death. Knockdown experiments identified BIM as a key signaling molecule that mediates Givinostat/Sorafenib-induced oxidative death of HL cells. Furthermore, in vivo xenograft studies demonstrated a 50% reduction in tumor burden (P<0.0001), a 5- to 15-fold increase in BIM expression (P < 0.0001) and a fourfold increase in tumor necrosis in Givinostat/Sorafenib-treated animals compared with mice that received single agents. These results provide a rationale for exploring Givinostat/Sorafenib combination in relapsed/refractory HL.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Apoptosis Regulatory Proteins / genetics
  • Apoptosis Regulatory Proteins / physiology*
  • Bcl-2-Like Protein 11
  • Carbamates / administration & dosage*
  • Cell Line, Tumor
  • Histone Deacetylase Inhibitors / administration & dosage*
  • Hodgkin Disease / drug therapy*
  • Hodgkin Disease / pathology
  • Humans
  • Imidazoles / pharmacology
  • Indoles / pharmacology
  • Membrane Proteins / genetics
  • Membrane Proteins / physiology*
  • Mice
  • Mice, SCID
  • Necrosis
  • Niacinamide / administration & dosage
  • Niacinamide / analogs & derivatives*
  • Phenylurea Compounds / administration & dosage*
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / physiology*
  • Reactive Oxygen Species / metabolism*
  • Sorafenib
  • Up-Regulation
  • Xenograft Model Antitumor Assays

Substances

  • Apoptosis Regulatory Proteins
  • BCL2L11 protein, human
  • Bcl-2-Like Protein 11
  • Bcl2l11 protein, mouse
  • Carbamates
  • Histone Deacetylase Inhibitors
  • Imidazoles
  • Indoles
  • Membrane Proteins
  • Phenylurea Compounds
  • Proto-Oncogene Proteins
  • Reactive Oxygen Species
  • necrostatin-1
  • Niacinamide
  • givinostat
  • Sorafenib