125I粒子持续低剂量率照射对人前列腺癌细胞的抑制作用

目的探讨^125I粒子持续低剂量率照射对人前列腺癌细胞株（PC3）增殖抑制以及对细胞周期的影响。方法^125I粒子（初始剂量率2.77cGy/h）和^60Coγ射线（吸收剂量率2.215Gy/min）对体外培养的PC3细胞进行0、0.5、1、1.5、2、4、6和8Gy照射,用细胞计数、锥虫蓝染色和集落形成法检测细胞增殖、细胞活力和细胞存活率的情况;用单击多靶模型拟合剂量存活曲线;用流式细胞仪检测细胞周期。结果随着照射剂量的增加,^125I粒子照射组的细胞生长比^60Coγ射线组更加明显地受到抑制（P〈0.05）。^125I粒子照射PC3细胞D0值为2.243,Dq为0.87,N为1.618,SF2为0.5。^60Co照射组PC3细胞放射生物学参数D0值为2.824,Dq为1.08,N为1.587,SF2为0.7。^60Co和125I粒子的RBE比值为1.4。与空白对照组相比,^125I粒子组和^60Co组4Gy照射细胞24h后均出现G2期阻滞。结论^125I粒子照射能抑制人前列腺癌细胞的增殖并能使PC3细胞阻滞于G2期。

The inhabitation effect of 125I seed irradiation on prostate cancer cell

Objective To study the effect on prostate cancer cell proliferation and cell cycle treated by continuous low dose rate 125 I irradiation. Methods PC3 cell was irradiated with 125 I (2.77 cGy/h) and 60 Co(2.215 Gy/min) at various doses.The cellular proliferation,vitality and cell surviving rate were evaluated by cytometric methods,typan-blue stain and the colony-forming assay after radiation.The cell cycle distribution was investigated by FCM. Results The death rate of PC3 cell exposed to 125 I was higher than that exposed to 60 Co gamma rays with the increase of the irradiation dose.The parameters of radiobiology of PC3 irradiated by 125 I seeds were:D_0=2.243,D_q=0.87,N=1.618,SF_2=0.5 whereas the parameters of 60 Co were:D_0=2.824,D_q=1.08,N=1.587,SF_2=0.7.The RBE for 125 I compared with 60 Co gamma rays is 1.4.The cell cycle distribution after 4 Gy 125 I or 60 Co irradiation was similar,with increasing in the proportion of cells in G_2 phase after 24 h. Conclusions 125 I irradiation could inhibit the proliferation of PC3 and induced G_2 phase arrest.