【摘要】 本文研究了HeLa细胞经过12C6+离子束辐照之后的DNA损伤效应,及辐照后p53激活的分子机制。运用中性单细胞电泳技术,检测了HeLa细胞经过4Gy 12C6+离子束辐照间隔0、3、6和12h之后DNA的损伤情况,及0.5、1、2和4Gy 12C6+离子束辐照后即时的DNA损伤情况。同时运用细胞生长实时监测仪监测了HeLa细胞在经过0、0.5和1Gy 12C6+离子束辐照之后的生长变化,并运用AO/EB双染检测了辐照细胞24h后的凋亡情况。另外,利用8mmol/L的咖啡因[抑制ATM(ataxia-telangiectasia,mutated)和ATR(ATM and Rad3-related kinase)]和20μmol/L的wortmannin[抑制ATM和DNA-PK(DNA-dependent protein kinase)]处理HeLa细胞后再进行1Gy 12C6+离子束辐照,通过westernblot检测p53的表达。结果显示,12C6+离子束辐照可造成HeLa细胞的DNA损伤,损伤随剂量升高而升高但随测定间隔时间降低,诱导HeLa细胞发生凋亡;而且辐照后p53表达升高。结果证明12C6+离子束辐照可造成HeLa细胞的DNA损伤并诱导损伤修复及凋亡等效应,损伤效应相关因子p53被激活,并且激活依赖于ATM。更多还原

【Abstract】 The aim of this study is to explore the DNA damage response of HeLa irradiated by 12C6+ beam and the mechanism of the p53 activation change in this response.In our present study,double strands break(DSB)of HeLa cells irradiated with 12C6+ beam were detected through neutral single cell gel electrophoresis,and AO/EB staining was used to detect the apoptosis of irradiated HeLa in 24h irradiation.Moreover,HeLa was pre-treated with caffeine(ATM and ATR inhibiting)or wormannin with certain concentrations(20μmol/L,ATM and DNA-PK inhibiting)and irradiated with 1Gy of 12C6+ beam,and the expression of p53 was detected with Western blot analysis.The results show that DSB of HeLa caused by 12C6+ beam increases with absorbed doses and decreases with the time after irradiation.The apoptosis percentage of irradiated HeLa increases with absorbed doses.It has been found that the p53 expression increases after irradiation,but has not significant increment with caffeine or wortmannin pre-treatment in cells.It can be deduced that the p53 activation is ATM-dependent,but not ATR and DNA-PK-dependent in HeLa DNA damage response induced by 12C6+ beam.更多还原