[The effects of DNA repair enzyme hMTH1 on HBx-induced malignant transformation of L02 cells].

Objective: To study the effects of the HBV x gene (HBx) on the biological characteristics and the expression of DNA repair enzyme hMTH1 mRNA of the L02/HBx transgene cell model.

Methods: Light microscopy was used to observe the morphologic characteristics of gene-transfected cell strain L02/HBx that stably expressed the HBx protein and the control groups of L02 and L02/pcDNA3.1. The changes of L02/HBx on the proliferation, cell cycle and apoptosis were observed by MTT assays and flow cytometry analysis respectively. Moreover, the malignant transformation of L02/HBx was assayed by colony formation in soft agar and the expression of DNA repair enzyme hMTH1 mRNA was assayed in each group by real-time qPCR.

Results: Inversion phase contrast microscope showed that the morphologic characteristics of L02/HBx had changed obviously compared with control groups. The MTT showed that L02/HBx proliferated more quickly and flow cytometry analysis indicated that HBx could accelerate the progression of cell cycle and inhibit apoptosis. Colony formation in soft agar demonstrated that the rate of colony formation of L02/HBx was remarkably higher than the L02 and the L02/pcDNA3.1 cells (P < 0.05). The real-time qPCR detection showed that the expression of hMTH1 mRNA in L02/HBx was significantly higher than that in the control groups (P < 0.05).

Conclusion: HBx could play an important role in the malignant transformation of L02/HBx and the over expression of hMTH1 mRNA.