Effects Of XPD And PPARγ On Proliferation Of Human Hepatoma G2Cell And The Expression Of ERG Gene

Objective：To investigate the effects of Xeroderma Pigmentosum Group D(XPD) Gene on proliferation of human hepatoma G2cell and the expression of ERGgene.Methods: The Human hepatoma cells (HepG2) was transfected with XPD geneand vacant vector plasmid pEGFP-N2by Lipofectamine2000, and the cells wereincubated with10umol/L GW9662(PPARγ inhibitor)for48hour. There are sixgroups in the study including blank control group, Lipofectamine group (Lip group),pEGFP-N2group (N2group), pEGFP-N2-XPD group（XPD group), pEGFP-N2-XPD+GW9662group and GW9662group. By using RT-PCR and Westernblotting, the expression levels of XPD， ERG，PPARγand cdk7were detected. Theapoptosis rate were examined with flow cytometry, and the cell viability was detectedby MTT.Results:The expressions of XPD mRNA and protein were increased remarkableafter pEGFP-N2-XPD transfected into HepG2cell（0.2075±0.0053，3.8042±1.0889，P <0.001）. Over-expression of XPD up-regulated the expressions ofPPARγ（0.6294±0.0218，0.0283±0.0009，P <0.001）,but down-regulated theexpressions of ERG（0.0091±0.0006，0.0518±0.0003，P <0.001）.The GW9662could blocked the effect(P <0.001).MTT results showed that the increased XPDexpression inhibited the cell proliferation．This inhibition induced by XPD can beinhibited by GW9662（0.5839±0.0804，P <0.001）．Flow cytometry resultsshowed that the up-regulated XPD expression increased XPD inhibited the viabilityof HepG2and promoted the apoptosis. However, the inhibition of PPARγ byGW9662blocked the effects of XPD（15.3217±0.8089，P<0.001）.Conclusion: XPD could inhibit the expression of ERG;XPD could inhibitproliferation and promote the apoptosis of human hepatoma G2cell via PPARγpathway;XPD could reduce the expression of ERG gene via PPARγpathway.