Abstract: Objective：To transfect wild-type XPD gene into human hepatoma cell line SMMC-7721 and to observe the expression of Ets-1 and Cdk6 gene and the influence in the growth and proliferation of SMMC-7721 cells. Methods：The pEGFP-N2-XPD was transfected into SMMC-7721 cells by Lipofectamine 2000TM. There were four groups in my study including SMMC-7721-pEGFP-N2-XPD group(XPD group)，SMMC-7721-pEGFP-N2 group(N2 group)，Lipofectamine group(Lip group) and blank control group. The expressions levels of XPD，Ets-1 and Cdk6 were detected by RT-PCR and Western blot. Flow cytometry(FCM) was used to analyze the cell cycle of SMMC-7721 cells. The cell proliferation was measured by MTT assay. Results: Compared with blank control group，N2 group and Lip group，the expression of XPD mRNA and protein was enhanced significantly in XPD group(P<0.01)，the expression of Ets-1 and Cdk6 mRNA and protein were decreased obviously(P<0.01). FCM showed that XPD prevented the hepatoma cells from G1 stage to S stage. The proliferation ability of SMMC-7721 cells was observably reduced after transfected by wild-type XPD gene(P<0.01). Conclusion: XPD gene may regulate the hepatoma cell proliferation by inhibiting the Ets-1 and Cdk6 gene.

Key words: liver neoplasms, XPD, Ets-1, Cdk6, transfect, cell cycle