放疗耐受的宫颈癌Hela细胞的生物学特性

 【目的】研究耐放疗的宫颈癌Hela细胞生物学特性的改变，并探讨其与宫颈癌肿瘤干细胞间的关系。【方法】采用多次分割剂量照射技术建立宫颈癌Hela细胞的耐放疗模型（Hela-R），实验分4组：Hela-R1组，Hela-R2组，Hela-R3组和对照组。四甲基偶氮唑蓝法检测细胞生长情况，克隆形成实验测定放射敏感性和克隆能力，流式细胞术检测细胞周期分布和增殖能力，球囊培养法检测细胞自我更新能力。【结果】Hela、Hela-R细胞接受照射后均呈现先加速增殖后出现生长抑制的现象。Hela-R1、Hela-R2、Hela-R3的细胞倍增时间分别为（43.4±1.0）h、（49.2±2.0）h和（48.7±3.3）h，克隆形成率分别为（20.3±4.0）%、（49.3±11.6）%和（6.3±5.9）%，S期细胞比例分别为（9.9±0.4）%、（13.0±0.9）%和（9.6±0.7）%，增殖指数（PI）分别为（27.3±2.6）%、（31.8±4.9）%和（37.4±8.0）%。与对照组比较，Hela-R3组的放射抗拒性增强。非粘附性球囊培养法培养Hela及Hela-R细胞可得到肿瘤细胞球，四组的球囊形成率分别为（9.9±0.4）%、（13.0±0.9）%、（9.6±0.7）%和（5.0±0.3）%。【结论】多次分割剂量照射可在体外建立宫颈癌Hela细胞的耐放疗模型，并可富集肿瘤干细胞；多次分割照射后，Hela细胞生长速度减慢，增殖能力有升高趋势，自我更新能力、克隆能力增强，细胞周期无明显变化。

Biological Characteristics in Cervical Cancer Cell Line Hela Tolerated to Radiation

【Object】 The aim of the study was to investigate biological behaviors of radioresistant cervical cancer cells.The relationship between radioresistant cancer cells and cancer stem cells would be discussed.【Methods】 Hela cells were treated with fractionated irradiation,yielding Hela-R,the radioresistant model.There were four groups: Hela-R1,Hela-R2,Hela-R3 and control.Biological characteristics,including cell growth,clone-generating capability,cell cycle distribution and proliferation,and tumor sphere-forming rate were detected by MTT assay,clone formation assay,flow cytometry assay and serum-free medium culturing,respectively.【Results】 Before growth inhibition,both the parental cells and the sub-lines Hela-R were accelerated proliferation by exposure to irradiation.In the three groups of Hela-R,cell doubling times were(43.4 ± 1.0)h,(49.2 ± 2.0)h,and(48.7 ± 3.3)h;the colony forming rates were(20.3 ± 4.0)%,(49.3 ± 11.6)%,and(6.3 ± 5.9)%;S-Phase Fraction were(17.6 ± 1.3)%,(20.0 ± 2.4)%,and(23.9 ± 2.3)%;Proliferation index(PI) were(27.3 ± 2.6)%,(31.8 ± 4.9)%,and(37.4 ± 8.0)%,respectively.Compared with the parental cells,cells in Hela-R3 were more radioresistant to electronic rays.The formation of tumor spheres could be observed when Hela cells and Hela-R cells were cultured in non-adherent serum-free medium,and tumor sphere-forming rates were(9.9 ± 0.4)%,(13.0 ± 0.9)%,(9.6 ± 0.7)%,and(5.0 ± 0.3)%,respectively.【Conclusion】Long-term fractionated radiation exposure conferred tolerance of ionizing radiation to the human tumor cells Hela,which is a method to establish radioresistant model and obtain tumor stem cells by radiation enrichment.Hela-R cells were more powerful in self-renew and cloning-generating capability,with a trend of proliferative capability increased,while the cellular growth was slower and cell cycle showed no significant change.