The role of XPB in cell apoptosis and viability and its relationship with p53, p21(waf1/cip1) and c-myc in hepatoma cells

Dig Liver Dis. 2006 Oct;38(10):755-61. doi: 10.1016/j.dld.2006.06.009. Epub 2006 Aug 17.

Abstract

Background: Accumulation of DNA damage has been implicated in hepatocarcinogenesis. XPB plays a pivotal part in repairing damaged DNA. However, up to now, the biological effect of XPB on hepatoma cells remains elusive.

Materials and methods: Here, we investigated the role of XPB in the apoptosis and the viability of hepatoma cells by using the terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end-labelling and cell viability assay; we also investigated their relationship with p53, p21(waf1/cip1) and c-myc by using the RT-PCR and Western blot.

Results: Compared with the control cells HepG2/pcDNA3.1 or HepG2, XPB-transfected HepG2 cells (HepG2/pcDNA3.1-XPB) displayed lower viability, weaker activity and higher apoptosis index. At the same time, an increased expression of p21(waf1/cip1) mRNA, protein and p53 protein in addition to a decreased expression of c-myc mRNA and protein were detected in HepG2/pcDNA3.1-XPB cells.

Conclusions: Our results indicated that XPB could inhibit the proliferation of hepatoma cells and had a positive effect on the expression of p53 and p21(waf1/cip1) but a negative effect on c-myc.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / physiology*
  • Cell Line, Tumor
  • Cell Survival
  • Cyclin-Dependent Kinase Inhibitor p21 / metabolism*
  • DNA Helicases / physiology*
  • DNA-Binding Proteins / metabolism*
  • DNA-Binding Proteins / physiology*
  • Gene Expression
  • Humans
  • RNA, Messenger / metabolism
  • Transcription Factors / metabolism*
  • Tumor Suppressor Protein p53 / metabolism*

Substances

  • CDKN1A protein, human
  • Cyclin-Dependent Kinase Inhibitor p21
  • DNA-Binding Proteins
  • MYCBP protein, human
  • RNA, Messenger
  • Transcription Factors
  • Tumor Suppressor Protein p53
  • XPBC-ERCC-3 protein
  • DNA Helicases