The role of XPB in cell apoptosis and viability and its relationship with p53, p21waf1/cip1 and c-myc in hepatoma cells

BackgroundAccumulation 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 methodsHere, 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, p21waf1/cip1 and c-myc by using the RT-PCR and Western blot.ResultsCompared 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 p21waf1/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.ConclusionsOur results indicated that XPB could inhibit the proliferation of hepatoma cells and had a positive effect on the expression of p53 and p21waf1/cip1 but a negative effect on c-myc.