Combination of AT-101/cisplatin overcomes chemoresistance by inducing apoptosis and modulating epigenetics in human ovarian cancer cells

Mol Biol Rep. 2013 Jun;40(6):3925-33. doi: 10.1007/s11033-012-2469-z. Epub 2012 Dec 27.


We investigated the effects of AT-101/cisplatin combination treatment on the expression levels of apoptotic proteins and epigenetic events such as DNA methyltransferase (DNMT) and histone deacetylase (HDAC) enzyme activities in OVCAR-3 and MDAH-2774 ovarian cancer cells. XTT cell viability assay was used to evaluate cytotoxicity. For showing apoptosis, both DNA Fragmentation and caspase 3/7 activity measurements were performed. The expression levels of apoptotic proteins were assessed by human apoptosis antibody array. DNMT and HDAC activities were evaluated by ELISA assay and mRNA levels of DNMT1 and HDAC1 genes were quantified by qRT-PCR. Combination of AT-101/cisplatin resulted in strong synergistic cytotoxicity and apoptosis in human ovarian cancer cells. Combination treatment reduced some pivotal anti-apoptotic proteins such as Bcl-2, HIF-1A, cIAP-1, XIAP in OVCAR-3 cells, whereas p21, Bcl-2, cIAP-1, HSP27, Clusterin and XIAP in MDAH-2774 cells. Among the pro-apoptotic proteins, Bad, Bax, Fas, phospho-p53 (S46), Cleaved caspase-3, SMAC/Diablo, TNFR1 and Cytochrome c were induced in OVCAR-3 cells, whereas, Bax, TRAILR2, FADD, p27, phospho-p53 (S46), Cleaved caspase-3, Cytochrome c, SMAC/Diablo and TNFR1 were induced in MDAH-2774 cells. Combination treatment also inhibited both DNMT and HDAC activities and also mRNA levels in both ovarian cancer cells. AT-101 exhibits great potential in sensitization of human ovarian cancer cells to cisplatin treatment in vitro, suggesting that the combination of AT-101 with cisplatin may hold great promise for development as a novel chemotherapeutic approach to overcome platinum-resistance in human ovarian cancer.

MeSH terms

  • Antineoplastic Combined Chemotherapy Protocols / pharmacology
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use
  • Apoptosis / drug effects
  • Apoptosis / genetics*
  • Caspase 3 / metabolism
  • Caspase 7 / metabolism
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Cell Survival / genetics
  • Cisplatin / pharmacology
  • Cisplatin / therapeutic use*
  • DNA (Cytosine-5-)-Methyltransferases / metabolism
  • DNA Fragmentation / drug effects
  • DNA Methylation / drug effects
  • DNA Methylation / genetics
  • Dose-Response Relationship, Drug
  • Drug Resistance, Neoplasm / drug effects
  • Drug Resistance, Neoplasm / genetics*
  • Drug Synergism
  • Epigenesis, Genetic* / drug effects
  • Female
  • Fluorescent Antibody Technique
  • Gossypol / analogs & derivatives*
  • Gossypol / pharmacology
  • Gossypol / therapeutic use
  • Histone Deacetylases / metabolism
  • Humans
  • Ovarian Neoplasms / drug therapy*
  • Ovarian Neoplasms / enzymology
  • Ovarian Neoplasms / genetics*
  • Ovarian Neoplasms / pathology


  • DNA (Cytosine-5-)-Methyltransferases
  • Caspase 3
  • Caspase 7
  • Histone Deacetylases
  • Gossypol
  • Cisplatin
  • gossypol acetic acid