CAJ | 학술논문

目的研究DNA聚合酶β(polβ)表达水平对苯并[a]芘(BaP)致细胞遗传毒性及基因组遗传不稳定性的影响,为BaP的致癌分子机制提供实验依据.方法采用3种具有相同遗传背景的小鼠胚胎成纤维细胞[polβ野生型(polβ+/+)、polβ缺陷型(polβ-/-)和polβ高表达型(polβoe)]作为模型,检测BaP对细胞的氧化损伤作用,细胞遗传毒性和基因组遗传不稳定性.结果随着BaP浓度的增加,3种细胞的存活率和克隆形成能力均下降.5.00和20.00 μmol/L BaP染毒时,polβ-/-细胞产生的ROS荧光强度均大于polβ+/+和polβoe细胞,差异均有统计学意义(P＜0.05).在5.00和20.00μmol/L时,polβ-/-卢细胞SOD活力为(76.56±2.84)和(62.78±4.28) U/mg pro,低于对照组[(84.85±3.59) U/mg pro]和polβ+/+细胞[(85.21 ±3.20)和(76.90±3.38) U/mg pro],20.00 μmol/L BaP染毒组polβoe细胞SOD活力[(82.59±4.64) U/mg pro]低于对照组[(88.58±6.77) U/mg pro]但高于相同浓度染毒的polβ +/+细胞,差异均有统计学意义(P＜0.05).1.25、5.00和20.00 μmol/L BaP染毒组的polβ-/-细胞的微核形成率明显高于polβ +/+细胞,5.00和20.00 μmol/LBaP染毒组的polβ oe细胞的微核形成率明显低于pol β+/+细胞,差异均有统计学意义(P＜0.05).5.00和20.00 μmol/L BaP染毒组polβ-/-细胞的HPRT基因突变频率为26.16×10-6和37.51×10-6,polβ oe细胞为27.68×10-6和38.63×10-6,均明显高于polβ +/+细胞(19.76×10-6和24.78×10-6),差异均有统计学意义(P＜0.05).结论 Polβ在保护细胞免受BaP造成的细胞毒性和遗传毒性方面具有积极的作用,其正常表达对于维持细胞基因组遗传稳定性具有重要的意义.
목적 연구DNA취합매β(polβ)표체수평대분병[a]비(BaP)치세포유전독성급기인조유전불은정성적영향,위BaP적치암분자궤제제공실험의거.방법 채용3충구유상동유전배경적소서배태성섬유세포[polβ야생형(polβ+/+)、polβ결함형(polβ-/-)화polβ고표체형(polβoe)]작위모형,검측BaP대세포적양화손상작용,세포유전독성화기인조유전불은정성.결과 수착BaP농도적증가,3충세포적존활솔화극륭형성능력균하강.5.00화20.00 μmol/L BaP염독시,polβ-/-세포산생적ROS형광강도균대우polβ+/+화polβoe세포,차이균유통계학의의(P＜0.05).재5.00화20.00μmol/L시,polβ-/-로세포SOD활력위(76.56±2.84)화(62.78±4.28) U/mg pro,저우대조조[(84.85±3.59) U/mg pro]화polβ+/+세포[(85.21 ±3.20)화(76.90±3.38) U/mg pro],20.00 μmol/L BaP염독조polβoe세포SOD활력[(82.59±4.64) U/mg pro]저우대조조[(88.58±6.77) U/mg pro]단고우상동농도염독적polβ +/+세포,차이균유통계학의의(P＜0.05).1.25、5.00화20.00 μmol/L BaP염독조적polβ-/-세포적미핵형성솔명현고우polβ +/+세포,5.00화20.00 μmol/LBaP염독조적polβ oe세포적미핵형성솔명현저우pol β+/+세포,차이균유통계학의의(P＜0.05).5.00화20.00 μmol/L BaP염독조polβ-/-세포적HPRT기인돌변빈솔위26.16×10-6화37.51×10-6,polβ oe세포위27.68×10-6화38.63×10-6,균명현고우polβ +/+세포(19.76×10-6화24.78×10-6),차이균유통계학의의(P＜0.05).결론 Polβ재보호세포면수BaP조성적세포독성화유전독성방면구유적겁적작용,기정상표체대우유지세포기인조유전은정성구유중요적의의.
Objective To explore the effects of DNA polymerase β expression level on the genotoxicity and genetic instability induced by benzo (a) pyrene (BaP),and provide experimental the basis for further study on the carcinogenic molecular mechanism of BaP.Methods Three kinds of cell lines with the identical genetic background,polβ wild-type cells (polβ +/+),polβ null cells (polβ -/-) and polβ overexpression cells (polβ oe) were applied as cellular models.The oxidative damage,genotoxicity and genetic instability induced by BaP were analyzed by using different methods respectively.Results Cell viability and colony forming ability of 3 kinds of cell lines exposed to BaP decreased with BaP.After treated with 5 and 20 μmol/L concentration of BaP,fluorescence intensity of polβ-/- cell line was significantly higher than that of other two cell lines (P＜0.05).When treated with 5.00 μmol/L and 20.00 μ mol/L concentration of BaP,the SOD activities (76.56±2.84 and 62.78±4.28 U/mg pro) of polβ-/- cell line were significantly lower than that (84.85±3.59) of control group and those (85.21±3.20 and 76.90±3.38 U/mg pro) of polβ +/+ cell line.In 20.00 μmol/L BaP group.SOD activity (82.59±4.64 U/mg pro) of polβoe cell line was lower than that (88.58t6.77 U/mg pro) of control but higher than that of polβ +/+ cell line (P＜0.05).In 1.25,5.00 and 20.00 μ mol/L concentration BaP groups,the micronucleus rates of polβ-/- cell line were much higher than those of polβ+/+ cell line (P＜0.05).In 5.00 and 20.00 μmol/L concentration BaP groups,the micronucleus rates of polβ oe cell line were significantly lower than those of polβ+/+ line (P＜0.05).In 5.00 and 20.00 μmol/L concentration BaP groups,HPRT gene mutation frequencies (26.16×10-6 and 37.51×10-6; 27.68×10-6 and 38.63×10-6) in polβ-/- cells and polβ oe cells were significantly higher than those (19.76×10-6 and 24.78×10-6) of polβ +/+ cells (P＜0.05).Conclusion Polβ could play a role in protecting the cells from the genotoxicity and genetic instability induced by BaP,and the normal expression level of polβ was indispensable for maintaining genome stability.