不同照射模式对人鼻咽低分化鳞癌细胞株CNE-2放射敏感性的影响研究

Radiosensitivity effect of different radiation pattern on human cell strain(CNE-2) of poor differential nasopharyngeal squamous cell carcinoma

目的:探索不同照射模式对人鼻咽低分化鳞癌细胞株(CNE-2)放射敏感性的影响。方法:运用克隆形成实验(courtenay assay),检测不同照射模式下CNE-2细胞的存活分数(SF),拟合细胞存活曲线。并运用四氮唑蓝法(MTT)进一步验证克隆形成实验的结果。结果:分别给予CNE-2细胞0、1、2、4、6、8 Gy的照射后,CNE-2细胞的SF值随照射剂量增加逐渐下降,并且在相同的剂量点,模拟调强照射(IMRT)组的SF均高于常规照射组;根据线性二次方程拟合CNE-2细胞存活曲线,α常规>αIMRT,β常规>βIMRT,N常规<NIMRT,D0常规<D0IMRT,Dq常规<DqIMRT;CNE-2细胞的增殖比例随照射剂量增加逐渐下降,并且在相同的剂量点,模拟IMRT组的增殖比例均高于常规照射组。结论:照射时间延长,CNE-2细胞存活分数增加,提示对肿瘤细胞的杀灭减少,放射敏感性下降,放射生物效应降低。

Objective： To explore the influence of different radiation pattern on radiosensitivity in cell strain （CNE-2） of nasopharyngeal squamous cell carcinoma. Methods： Surviving fraction（SF） was analyzed by courtenay assay, fitting cell survival curve; Cell growth inhibition was measured by MTT. Results： There were some different radiation doses including 0, 1, 2, 4, 6, 8 Gy, SF was decreasing with the radiation dose rised. Compared with simulation IMRT （SIMRT） group, SF of convention radiation （CR） group was lower in every dose point; Fitting cell survival curve by linear quadratic equation and multi-target one-shot model, αCR 〉αSIMRT ,βCR 〉βSIMRT ,NCR〈 NSIMRT , DoCR〈DoSIMRT , DqCR〈DqSIMRT; cell proliferation rates was decreasing with the radiation dose arised. Compared with SIMRT group, cell proliferation rates of CR group was lower in every dose point. Conclusions. SF was increasing with the radiation time rised. Long beam interruption may be one of the mechanisms responsible to decrease radiosensitivity and radiobiological effect.