Synergetic effects of DNA demethylation and histone deacetylase inhibition in primary rat hepatocytes

Invest New Drugs. 2012 Aug;30(4):1715-24. doi: 10.1007/s10637-011-9659-8. Epub 2011 Mar 29.

Abstract

Both, DNA methylation and histone deacetylation play a crucial role in cancer development by silencing the expression of specific tumour suppressor genes. Several studies describe the use of combinations of DNA methyltransferase inhibitors (DNMT-i) and histone deacetylase inhibitors (HDAC-i) as an improved strategy to treat neoplasms. However, no information is available concerning their biological impact on healthy, non-malignant cells, including hepatocytes. Therefore, the effects of the combination of the DNMT-i decitabine (DAC) with the HDAC-i 6-[(4-pyrrolidine-1-ylbenzoyl) amino] hexanoic acid hydroxamate (AN-8) on cell proliferation and differentiation were examined in primary rat hepatocyte cultures. We found that, upon simultaneous exposure of the cells to both compounds, a synergetic anti-proliferative outcome was achieved. This inhibition of DNA synthesis was accompanied by a reduced expression of cyclin-dependent kinase 1 (cdk1), a key cell cycle marker that controls the S/G2/M transition. Compared to exposure of the cells to each agent separately, the combination of lower concentrations of both DAC and AN-8 promoted the maintenance of the differentiated phenotype of the cells as a function of culture time. The functionality of the hepatocytes was evidenced by an increased expression of the phase I biotransformation enzyme cytochrome P 450 (CYP) 1A1 and albumin secretion capacity when both agents were used in combination.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Albumins / metabolism
  • Animals
  • Azacitidine / analogs & derivatives
  • Azacitidine / pharmacology
  • Biomarkers / metabolism
  • CDC2 Protein Kinase / metabolism
  • Cell Cycle / drug effects
  • Cell Proliferation / drug effects
  • Cell Shape / drug effects
  • Cells, Cultured
  • DNA / biosynthesis
  • DNA Methylation / drug effects*
  • Decitabine
  • Drug Synergism
  • Epidermal Growth Factor / pharmacology
  • Hepatocytes / cytology
  • Hepatocytes / drug effects*
  • Hepatocytes / enzymology
  • Hepatocytes / metabolism*
  • Histone Deacetylase Inhibitors / pharmacology*
  • Hydroxamic Acids / pharmacology
  • Rats

Substances

  • Albumins
  • Biomarkers
  • Histone Deacetylase Inhibitors
  • Hydroxamic Acids
  • Epidermal Growth Factor
  • Decitabine
  • DNA
  • CDC2 Protein Kinase
  • Azacitidine