title: The effects of HBx gene on the expression of DNA repair enzymes hOGG1 and hMYHalpha mRNA in HepG2 cells.
abstract: To observe the alteration in the expression of DNA repair enzymes hOGG1 and hMYHalpha and the change in 8-OHdG levels in the HBx gene-transfected cells HepG2/HBx and to explore the mechanisms of the HBV-associated hepatocellular carcinoma, the gene-transfected cells HepG2/HBx which stably expressed HBx was established, and the effect of HBx on the cell cycle and proliferation of HepG2 was examined. By using the beta-actin as the interior control, real-time polymerase chain reaction (Real-time qPCR) was employed to quantitatively detect the expression of DNA repair enzymes hOGG1 and hMYHalpha in the HepG2/HBx, the control cells HepG2 and HepG2 transfected with pcDNA3.1 vector (HepG2/pDNA3.1). The 8-OHdG levels were determined by HPLC/ECD in the established gene-transfected cells HepG2/HBx and the control cells HepG2 and HepG2/pcDNA3.1. Our results showed that the expression of DNA repair enzyme hMYHalpha in the HepG2/HBx (0.021+/-0.007) was significantly lower than that of HepG2 (0.099+/-0.041) (P<0.05) and HepG2/pDNA3.1 (0.121+/-0.005) (P<0.05). However, the no significant differences existed in the expression of DNA repair enzyme hOGG1 among the three cell strains (P>0.05). The 8-OHdG level in the HepG2/HBx was significantly higher than that in HepG2 and HepG2/pcDNA3.1 (P<0.05). It is concluded that HBx gene may inhibit the expression of DNA repair enzyme hMYHalpha mRNA to impair the ability to repair the intracellular DNA oxidative damage, to increase the oxidative DNA-adduct 8-OHdG and to affect the nucleotide excision repair function, thus participate in the occurrence and development of hepatocellular carcinoma.
authors.affiliation: Department of Gastroenterology and Hepatology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China. b.cheng@tjh.tjmu.edu.cn
authors.forename: Bin
authors.initials: B
authors.lastname: Cheng
authors.forename: Xiaorong
authors.initials: X
authors.lastname: Guo
authors.forename: Yaochu
authors.initials: Y
authors.lastname: Zheng
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Chunyan
authors.initials: C
authors.lastname: Liu
authors.forename: Peiyuan
authors.initials: P
authors.lastname: Li
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D045647:DNA Glycosylases / Q000235:genetics / Q000378:metabolism*; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D056945:Hep G2 Cells; D006801:Humans; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics*; D054334:Viral Regulatory and Accessory Proteins
chemical_list: D012333:RNA, Messenger; D015534:Trans-Activators; D054334:Viral Regulatory and Accessory Proteins; C057628:hepatitis B virus X protein; D000080242:8-Hydroxy-2'-Deoxyguanosine; D045647:DNA Glycosylases; C061738:mutY adenine glycosylase; C479058:oxoguanine glycosylase 1, human; D003849:Deoxyguanosine