Effect of Hepatitis B Virus X Gene on the Expression of Spastic Paraplegia 21

OBJECTIVE:To investigate the effect of hepatitis B virus(HBV) X gene on the expression of SPG21.METHODS:The expressions of SPG21 mRNA and protein in HepG2 and HepG2.2.15 cells were tested by RT-PCR and western blot. HepG2 cells were co-transfected with reporter plasmid pGL3-SPG21 and plasmids carrying individual genes of HBV, the luciferase activity was measured and the expressions of SPG21 were detected by RT-PCR and western blot.RESULTS:The expressions of SPG21 mRNA and protein were higher in HepG2.2.15 cells than in HepG2 cells (0.36+/-0.06 vs 0.21+/-0.05, P value is less than 0.05). The activity of SPG21 in HepG2 cells transfected with pCMV-X was higher (875+/-27 vs 67+/-12, P value is less than 0.01) as compared to blank control group (transfected with pCMV-tag2B). HBV X gene enhanced SPG21 gene promoter activity, SPG21 mRNA expression and SPG21 protein production in HepG2 cells in a dose-dependent manner.CONCLUSION:HBV X gene can specially activate SPG21 expression.