宫颈癌放疗患者外周血淋巴细胞DNA损伤的研究

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。

Evaluation of DNA damage induced by radiotherapy in cervical cancer patients

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(P<0.01),showing a linear relationship from 0 to 60 Gy.The regression equation was y=12.133+0.230x,r=0.964(P<0.05).The tail length showed significant increase in radiation groups compared with pre-radiation(P<0.01).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)(P<0.01).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.