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


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.
Hu
G-M
GM
Department of Gastroenterology, Second Affiliated Hospital, Nanchang University, Nanchang City (330006), Jiangxi Province, China.
Liu
L-M
LM
Zhang
J-X
JX
Hu
X-D
XD
Duan
H-J
HJ
Deng
H
H
He
M
M
Luo
Z-J
ZJ
Liu
J-M
JM
Luo
J
J
D017209:Apoptosis / Q000502:physiology*; D045744:Cell Line, Tumor; D002470:Cell Survival; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism*; D004265:DNA Helicases / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000378:metabolism* / Q000502:physiology*; D015870:Gene Expression; D006801:Humans; D012333:RNA, Messenger / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D004268:DNA-Binding Proteins; C116115:MYCBP protein, human; D012333:RNA, Messenger; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53; C072022:XPBC-ERCC-3 protein; D004265:DNA Helicases