氧自由基诱导鸭乙型肝炎病毒DNA整合及其细胞传代研究

Duck hepatitis B virus DNA integration induced by oxidative radicals and its transmission from parent cells to offspring ones

目的 探讨氧自由基对鸭乙型肝炎病毒（ＤＨＢＶ）ＤＮＡ在受感染细胞ＤＮＡ上整合发生的影响以及整合后ＤＨＢＶ ＤＮＡ的细胞传代性。方法 选择鸡肝癌细胞株－ＬＭＨＤ２１－６，在其由单个细胞培养至３×１０＾７－５×１０＾７个细胞（共２３代）的过程中，用低浓度Ｈ２Ｏ２（１０．０μｍｏｌ／Ｌ）作用于细胞；ＴＵＮＥＬ法检测细胞ＤＮＡ链断裂情况；Ｓｏｕｔｈｅｎ ｂｌｏｔ技术观察细胞ＤＮＡ上新的整合型ＤＨＢＶ

Objective To investigate the role of oxidative radicals in duck hepatitis B virus DNA (DHBV DNA)integration and the transmission of integrated DHBV DNA from parent cells to their offspring cells. Methods TUNELassay and Southern blot hybridizalion were used to detect lhe cellular DNA strand breaks and the incidence of new type ofDHBV DNA integration into cellular DNA of LMHD21-6 cell line after the cells treated by low dose of hydrogen peroxide(10.0μ mol/L) during its gr wth from one cell to 3 ×107~5 ×10~7 cells. Results The rate of cell death induced by low doseof H_2O_2 (10.0 μ mol/L) was 32.0%, but that induced by high dose (> 10.0 μ mol/L) was more than 50.0%. At the same time,the incidence of new DHBV DNA integration into cellular DNA induced by 10.0 μ mol/L of H_2O_2 was 50.0% (6/12) and thatin control group was 8.33% (1/12). There was a significant difference between the two groups (P < 0.05 ). Besides, the newintegrated DHBV-DNA in the parent cells could be found in the DNA of their offspring cells with the same size of base pair.Conclusion Oxidative radicals is one of the important inducing factors in DHBV-DNA integration into cellular DNA andthe integrated DHBV-DNA is able to transmit from the parent cells to their offspring cells stably.[