PP2A activation alone and in combination with cisplatin decreases cell growth and tumor formation in human HuH6 hepatoblastoma cells

PLoS One. 2019 Apr 10;14(4):e0214469. doi: 10.1371/journal.pone.0214469. eCollection 2019.

Abstract

Despite an increase in incidence, treatments for hepatoblastoma remain virtually unchanged for the past 20 years, emphasizing the need for novel therapeutics. FTY720 (fingolimod) is an immunomodulator approved for use in multiple sclerosis in children that has been demonstrated to have anti-cancer properties in multiple cancer types. We have demonstrated that FTY720 activates PP2A in hepatoblastoma, but does not do so via inhibition of the endogenous inhibitors, CIP2A and I2PP2A, as previously observed in other cancers. PP2A activation in hepatoblastoma decreased cell viability, proliferation, and motility and induced apoptosis. In a subcutaneous xenograft model, FTY720 decreased tumor growth. FTY720 in combination with the standard chemotherapeutic, cisplatin, decreased proliferation in a synergistic manner. Finally, animals bearing subcutaneous hepatoblastoma xenografts treated with FTY720 and cisplatin in combination had significantly decreased tumor growth compared to those treated with either drug alone. These findings show that targeting PP2A with FTY70 shows promise in the treatment of hepatoblastoma and that combining FTY720 with cisplatin may be a novel and effective strategy to better treat this devastating pediatric liver tumor.

Publication types

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

MeSH terms

  • Animals
  • Apoptosis
  • Autoantigens / metabolism
  • Cell Cycle
  • Cell Line, Tumor
  • Cell Movement
  • Cell Proliferation
  • Cell Survival
  • Cisplatin / administration & dosage*
  • DNA-Binding Proteins
  • Female
  • Fingolimod Hydrochloride / administration & dosage
  • Hepatoblastoma / drug therapy
  • Hepatoblastoma / pathology*
  • Histone Chaperones / metabolism
  • Humans
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Liver Neoplasms / drug therapy
  • Liver Neoplasms / pathology*
  • Membrane Proteins / metabolism
  • Mice
  • Mice, Nude
  • Neoplasm Transplantation
  • Protein Phosphatase 2 / metabolism*
  • Transcription Factors / metabolism

Substances

  • Autoantigens
  • CIP2A protein, human
  • DNA-Binding Proteins
  • Histone Chaperones
  • Intracellular Signaling Peptides and Proteins
  • Membrane Proteins
  • SET protein, human
  • Transcription Factors
  • PPP2CA protein, human
  • Protein Phosphatase 2
  • Fingolimod Hydrochloride
  • Cisplatin