Molecular and Cellular Biochemistry

, Volume 399, Issue 1–2, pp 269–278 | Cite as

DNA-PKcs deficiency sensitizes the human hepatoma HepG2 cells to cisplatin and 5-fluorouracil through suppression of the PI3K/Akt/NF-κB pathway

  • Yuan Fang
  • Zongtao Chai
  • Dansong Wang
  • Tiantao Kuang
  • Wenchuan Wu
  • Wenhui Lou


The aim of the present study was to investigate the effects of DNA-PKcs deficiency on the chemosensitivity of human hepatoma HepG2 cells to cisplatin (CDDP) and 5-fluorouracil (5-Fu), and to explore the underlying molecular mechanism. After transfection with DNA-PKcs siRNA or control siRNA, HepG2 cells were exposed to combination treatment of CDDP and 5-Fu. The cell viability, DNA damage, cell apoptosis, intracellular reactive oxygen species and glutathione (GSH) level, expression of apoptosis related proteins, activity of phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) pathway, and nuclear factor-κB (NF-κB) pathways were assessed. The combination of CDDP and 5-Fu had a synergistic cytotoxic effect in HepG2 cells in terms of the cell viability, DNA damage, apoptosis, and oxidative stress level. DNA-PKcs siRNA could sensitize the HepG2 cells to the combined treatment. DNA-PKcs suppression further reduced the Akt phosphorylation level and Bcl-2 expression in HepG2 cells exposed to CDDP and 5-Fu, but enhanced the expression of pro-apoptotic proteins p53 and caspase-3. Moreover, CDDP could inhibit the transcriptional activity of NF-κB through degradation of IkB-α, while 5-Fu alone seemed in some extent increases the NF-κB activity. The combined treatment with CDDP and 5-Fu resulted in significantly decrease of the transcriptional activity of NF-κB, which was further aggravated by DNA-PKcs siRNA treatment. In conclusion, DNA-PKcs suppression had complementary effects in combination with CDDP and 5-Fu treatment in HepG2 cells, which was associated with suppression of NF-κB signaling pathway cascade, activation of caspase-3 and p53, as well as down-regulation of Bcl-2 and GSH.


DNA-PKcs HepG2 cells Apoptosis Oxidative stress NF-κPI3K/AKT pathway Bcl-2 GSH 



The study was supported by Special Research Fund for public welfare from Ministry of Health of China (201202007)

Conflict of interest

The authors declare that there are no conflicts of interest.


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Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  • Yuan Fang
    • 1
  • Zongtao Chai
    • 2
  • Dansong Wang
    • 1
  • Tiantao Kuang
    • 1
  • Wenchuan Wu
    • 1
  • Wenhui Lou
    • 1
  1. 1.Department of General Surgery, Zhongshan HospitalFudan UniversityShanghaiPeople’s Republic of China
  2. 2.Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Zhongshan Hospital, Liver Cancer InstituteFudan UniversityShanghaiPeople’s Republic of China

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