宫颈癌放疗患者外周血淋巴细胞DNA损伤的研究

Evaluation of DNA damage induced by radiotherapy in cervical cancer patients

目的:评价宫颈癌放疗患者外周血淋巴细胞的DNA损伤。方法:取15例宫颈鳞癌放疗患者放疗前及放疗累积剂量为10、20、30、40、50、60Gy时的外周静脉血,以彗星实验检测淋巴细胞的DNA损伤。结果:各累积剂量组淋巴细胞DNA拖尾率比照射前显著升高(P<0.01),并且在0～60Gy之间,拖尾率与累积照射剂量之间成线性关系,回归方程为y=12.133+0.230x,相关系数r=0.964(P<0.05)。各累积剂量组尾长比照射前均增加(P<0.01),在照射剂量累积30Gy时,尾长达最大。之后随照射累积剂量的进一步增加,尾长稍有下降,但是与照射前相比仍持续在较高的水平(P<0.01),尾长与累积剂量间不成线性关系。结论:宫颈癌患者放疗后可造成外周血淋巴细胞DNA损伤。

OBJECTIVE：To assess the DNA damage by comet assay in cervical cancer patients undergoing radiotherapy.METHODS：Blood samples were collected from 15 cervical cancer patients exposed to radiation at the accumulated dose of 0,10,20,30,40,50,60 Gy.DNA damage was measured by comet assay.RESULTS：Rate of lymphocyte DNA tailing in radiation groups increased significantly compared with to pre-radiation（P0.01）,showing a linear relationship from 0 to 60 Gy.The regression equation was y=12.133＋0.230x,r=0.964（P0.05）.The tail length showed significant increase in radiation groups compared with pre-radiation（P0.01）.At the accumulated dose of 30 Gy,the tail length reached the peak value.The tail length decreased a little,but remained at a higher level still when dose was higher than 30 Gy,compared to pre-radiation（0 Gy）（P0.01）.There was no dose-effect relationship between tail length and accumulated dose.CONCLUSION：Radiotherapy may induce DNA damage in cervical cancer patients. Evaluation of the radiation- damage by comet assay has a high sensitivity.