Downregulation of xIAP expression by small interfering RNA inhibits cellular viability and increases chemosensitivity to methotrexate in human hepatoma cell line HepG2

J Chemother. 2006 Oct;18(5):525-31. doi: 10.1179/joc.2006.18.5.525.


The aim of this study was to investigate whether downregulating the expression of xIAP by RNAi (RNA interference) technology can induce the apoptosis of HepG2 cells, inhibit cellular viability and increase chemosensitivity of cancer cells. HepG2 cells were transfected with U6 promoter plasmids coding for short interfering RNAs (siRNAs) targeting xIAP. RT-PCR and western blot analysis were used to assess the mRNA and protein levels of xIAP expression. T he suppression efficiency o f xIAPby RNAi was evaluated using the MTT assay for cellular viability and Annexin V-PI binding assay for apoptosis. These results showed that siRNAs reduced cellular viability and increased cellular apoptosis. Moreover, downregulation of xIAP expression enhanced the chemosensitivity of HepG2 cells to methotrexate. These results suggest that the downregulation of xIAP by RNAi could potentially be used as a therapeutic strategy for human hepatocellular carcinoma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antimetabolites, Antineoplastic / therapeutic use
  • Apoptosis / drug effects
  • Base Sequence
  • Carcinoma, Hepatocellular / drug therapy
  • Carcinoma, Hepatocellular / metabolism*
  • Cell Line, Tumor
  • Cell Survival / drug effects*
  • Down-Regulation
  • Drug Resistance, Neoplasm / drug effects*
  • Genetic Vectors / chemical synthesis
  • Humans
  • Liver Neoplasms / drug therapy
  • Liver Neoplasms / metabolism*
  • Methotrexate / therapeutic use*
  • Molecular Sequence Data
  • RNA, Small Interfering / pharmacology*
  • Sequence Homology, Nucleic Acid
  • Substrate Specificity
  • X-Linked Inhibitor of Apoptosis Protein / metabolism*


  • Antimetabolites, Antineoplastic
  • RNA, Small Interfering
  • X-Linked Inhibitor of Apoptosis Protein
  • Methotrexate