Challeton C, Branea F, Schlumberger M, Gaillard N, de Vathaire F, Badie C, Antonini P, Parmentier C
Service de Médecine Nucléaire, INSERM U 66, Institut Gustave Roussy, Villejuif, France.
Int J Radiat Oncol Biol Phys. 1997 Jan 1;37(1):163-9. doi: 10.1016/s0360-3016(96)00449-x.
This study attempted to establish cell lines derived from human differentiated thyroid tumors, and to characterize and evaluate the radiation dose-rate effect.
Two cell lines (K1 and K2) were derived from papillary carcinomas, one (K7) from a follicular less-differentiated carcinoma and one (A14) from a follicular adenoma. Cell-survival curves after irradiation were established by the in vitro colony method. Radiation doses were delivered either at a high (45.9 Gy/h) or low dose rate (0.6 Gy/h) by a 60Co source. The data were analyzed according to the linear quadratic and multitarget model of radiation action.
Doubling times were around 24 h. All cell lines were positive for intracellular thyroglobulin. Cyclic adenosine monophosphate (cAMP) response to thyrotropin (TSH) was significant for the cell lines derived from the follicular adenoma and follicular carcinoma. The two cell lines derived from papillary carcinomas were tumorigenic after inoculation into nude mice. After high-dose-rate irradiation, the surviving fraction at 2 Gy (SF2) was not significantly different for the three malignant cell lines K1, K2, and K7, and ranged from 0.39 to 0.42. For the adenoma cell line A14, we found a higher radiosensitivity with a lower SF2 value and a higher alpha parameter. After low-dose-rate irradiation, only one cell line (K2) showed a significant low-dose-rate sparing with a dose reduction factor of 1.35.
The major result of our study is the weak effect of the dose rate on the survival of thyroid cell lines.
本研究试图建立源自人分化型甲状腺肿瘤的细胞系，并对辐射剂量率效应进行表征和评估。
两个细胞系（K1和K2）源自乳头状癌，一个（K7）源自低分化滤泡状癌，一个（A14）源自滤泡性腺瘤。通过体外集落法建立照射后的细胞存活曲线。使用60Co源以高剂量率（45.9 Gy/h）或低剂量率（0.6 Gy/h）给予辐射剂量。根据辐射作用的线性二次模型和多靶模型对数据进行分析。
倍增时间约为24小时。所有细胞系的细胞内甲状腺球蛋白均呈阳性。源自滤泡性腺瘤和滤泡状癌的细胞系对促甲状腺激素（TSH）的环磷酸腺苷（cAMP）反应显著。源自乳头状癌的两个细胞系接种到裸鼠后具有致瘤性。高剂量率照射后，三种恶性细胞系K1、K2和K7在2 Gy时的存活分数（SF2）无显著差异，范围为0.39至0.42。对于腺癌细胞系A14，我们发现其放射敏感性较高，SF2值较低且α参数较高。低剂量率照射后，只有一个细胞系（K2）表现出显著的低剂量率 sparing，剂量降低因子为1.35。
我们研究的主要结果是剂量率对甲状腺细胞系存活的影响较弱。
