The histone deacetylase inhibitor OBP-801 has in vitro/in vivo anti-neuroblastoma activity

Pediatr Int. 2022 Jan;64(1):e15159. doi: 10.1111/ped.15159.


Background: Patients with high-risk neuroblastoma have a poor prognosis; new therapeutic agents are therefore required. We investigated the antitumor effects of OBP-801, a novel histone deacetylase inhibitor, its underlying mechanism, and its potential as a therapeutic agent for patients with neuroblastoma.

Methods: The study included five human neuroblastoma cell lines: IMR32, GOTO, KP-N-RTBM, SK-N-AS, and SH-SY5Y. We investigated cell proliferation, cell cycle status, protein expression patterns, and apoptosis in neuroblastoma cells after OBP-801 treatment in vitro. Cell survival rate and cell cycle were analyzed using the WST-8 assay and flow cytometry, respectively. Apoptosis was detected using annexin V staining, and the expression of apoptosis-related proteins was investigated by western blotting. The antitumor activity of OBP-801 was examined in an in vivo xenograft mouse model.

Results: Dose-effect curve analysis showed that the mean half-maximal inhibitory concentration value was 5.5 ± 5.9 nM for the MYCN-amplified cell lines (IMR32, GOTO, and KP-N-RTBM) and 3.1 ± 0.7 nM for the MYCN-nonamplified cell lines (SK-N-AS and SH-SY5Y). OBP-801 inhibited cell proliferation and growth in all the cell lines. It induced G2/M phase arrest through the p21 (CDKN1A) pathway, increasing histone H3 levels and, subsequently, apoptosis in human neuroblastoma cells. OBP-801 suppressed the growth of neuroblastoma cells in the mouse xenograft model.

Conclusions: Overall, OBP-801 induces M-phase arrest and apoptosis in neuroblastoma cells via mitotic catastrophe. Our results indicate that OBP-801 is a promising therapeutic agent with fewer adverse effects for patients with neuroblastoma.

Keywords: OBP-801; histone deacetylase inhibitors; neuroblastoma.

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Cell Proliferation
  • Histone Deacetylase Inhibitors / pharmacology
  • Histone Deacetylase Inhibitors / therapeutic use
  • Humans
  • Mice
  • N-Myc Proto-Oncogene Protein / therapeutic use
  • Neuroblastoma* / drug therapy
  • Neuroblastoma* / pathology
  • Peptides, Cyclic / pharmacology
  • Peptides, Cyclic / therapeutic use


  • Histone Deacetylase Inhibitors
  • N-Myc Proto-Oncogene Protein
  • Peptides, Cyclic
  • YM753 compound