CAJ | 학술논문

目的探讨125I粒子持续性低剂量率照射下肿瘤细胞的凋亡和周期改变.方法采用CL187人结肠癌细胞系体外培养,分为空白对照组、60Co单次高剂量率照射组、125I低剂量率照射组.单次高剂量率组以2 Gy/min给予细胞1、2、4、6、8和10 Gy的照射,低剂量率组以2.77 cGy/h的初始剂量率给予相同剂量照射,照射后24 h根据肿瘤细胞死亡率和14 d克隆形成率评价不同照射方式对肿瘤细胞的杀伤效果.同时,用放射性125I粒子以2.77 cGy/h的剂量率,给予细胞2、5和10 Gy的照射,应用流式细胞术测量其凋亡和细胞周期的变化.结果低剂量率组照射后细胞死亡率在1 Gy时低于60Co单次高剂量率组,随着剂量的上升,2 Gy后,超过单次高剂量率组,但整体上125I粒子照射后细胞死亡率高于60Co组(P=0.011).125I持续性低剂量率照射组的克隆增殖率明显低于60Co单次高剂量率组(P=0.0021).低剂量率照射下,2 Gy时仅能引起G2/M期阻滞和凋亡,5 Gy时达到峰值,10 Gy时细胞周期阻滞和凋亡的比率依然很高,但相对于5 Gy有所下降;同时G2/M期阻滞和凋亡变化呈现出相同的趋势.结论在相同剂量条件下,125I粒子持续照射低剂量率照射比60Co单次高剂量照射对CL187肿瘤细胞具有更强的杀伤效应;G2/M期阻滞引起的凋亡是低剂量率照射杀伤肿瘤细胞的主要机制.
목적 탐토125I입자지속성저제량솔조사하종류세포적조망화주기개변.방법 채용CL187인결장암세포계체외배양,분위공백대조조、60Co단차고제량솔조사조、125I저제량솔조사조.단차고제량솔조이2 Gy/min급여세포1、2、4、6、8화10 Gy적조사,저제량솔조이2.77 cGy/h적초시제량솔급여상동제량조사,조사후24 h근거종류세포사망솔화14 d극륭형성솔평개불동조사방식대종류세포적살상효과.동시,용방사성125I입자이2.77 cGy/h적제량솔,급여세포2、5화10 Gy적조사,응용류식세포술측량기조망화세포주기적변화.결과 저제량솔조조사후세포사망솔재1 Gy시저우60Co단차고제량솔조,수착제량적상승,2 Gy후,초과단차고제량솔조,단정체상125I입자조사후세포사망솔고우60Co조(P=0.011).125I지속성저제량솔조사조적극륭증식솔명현저우60Co단차고제량솔조(P=0.0021).저제량솔조사하,2 Gy시부능인기G2/M기조체화조망,5 Gy시체도봉치,10 Gy시세포주기조체화조망적비솔의연흔고,단상대우5 Gy유소하강;동시G2/M기조체화조망변화정현출상동적추세.결론 재상동제량조건하,125I입자지속조사저제량솔조사비60Co단차고제량조사대CL187종류세포구유경강적살상효응;G2/M기조체인기적조망시저제량솔조사살상종류세포적주요궤제.
Objective To study the response patterns of CL187 cell lines irradiated with low dose rates of 125I seeds.Methods CL187 cells were exposed with radioactive.125I seeds and 60Co source,which were put under culture plate.The radiation response at different doses and dose-rates were evaluated through cell-proliferation assessed by the colony-forming assay and death rate after irradiation.Meanwhile,cell cycle arrest and apoptosis were measured by flow cytometry after 2,5 and 10 Gy of low dose rate irradiation.Remits It was shown that the cell-killing effects were related to the doses and dose-rates.At 1 Gy,comparison of the death rate between the low and high dose rate showed that the higher dose rate led to increased cell responses,but at the doses higher than 2 Gy,the effect of the low dose rate were more efficient.At the same dose,the survival fraction of 125I was always lower than that of 60Co.Exposed to the low dose rate irradiation,apoptosis and G2/M cell cycle arrest rose a little at 2 Gy,the peak appeared at 5 Gy,and the ratio at 10 Gy Was also high but lower than at 5 Gy.Furthermore,the G2/M cell cycle arrest and apoptosis changed together along with the doses.Conclusions At the same dose,125I seeds have more cell-killing effects than 60Co at high dose rate irradiation.Apoptosis following the G2/M cell cycle arrest were the main mechanism of cell-killing effects under low dose rate irradiation.