医用高能碳离子线对不同乏氧状况下中国仓鼠卵巢细胞（CHO-K1）的放射效应研究
发布时间：2018-08-05 20:46
【摘要】：目的：已知乏氧可以直接通过氧剥夺或间接影响细胞生理功能而导致辐射抗性。为了研究乏氧细胞对低线性能量传递X射线以及高线性能量传递碳离子线的放射敏感性,以及慢性氧缺乏下细胞周期分布的改变对细胞存活的影响。X线和医用高能碳离子线对不同乏氧状况下中国仓鼠卵巢细胞CHO-Kl细胞的放射效应进行研究。相应的细胞克隆存活和细胞周期分布进行了测量。 材料与方法：,在标准条件下培养的CHO-K1细胞,进行有氧(空气),乏氧(0.5%O2,94.5%N2,5%CO2)或无氧(95%N2,5%CO2)状况下的实验。为了达到急性无氧或乏氧,5个特殊设计的乏氧照射盒串接到气瓶,相应的混合气体(95%N2,5%CO2或0.5%的O2,94.5%的氮气,5%C02)以200毫升/分钟流量进行气体置换2小时。在达到急性无氧或乏氧后,将乏氧照射盒密闭并保持气密性24小时,盒内细胞即达慢性无氧或乏氧状态。而将乏氧照射盒内的细胞重新暴露在空气中一定时间,即可进行再氧合实验。用250kVp的X射线及碳离子射线进行照射。碳离子的平均线性能量传递为103keV/u m,用1cm的扩展Bragg峰碳离子对CHO-K1细胞进行照射,进行克隆形成实验。在无氧、乏氧情况下及慢性无氧或乏氧后再氧合情况下的细胞周期变化进行检测。 结果：从不同氧状态下的存活曲线,我们可以看到,慢性乏氧的细胞和急性乏氧相比具有非常相似的放射敏感性。而慢性无氧的细胞和急性无氧相比具有相对更高的放射敏感性；慢性无氧再氧合1小时的细胞也显示了相对于有氧细胞的放射敏感性增加；这在X线和碳离子线照射情况下均有发现。相应细胞周期分布的检测显示乏氧状态下细胞周期分布相当均匀,而慢性乏氧再氧合后的研究也显示了细胞周期随时间的均一性变化,与有氧细胞相比无明显区别。而再氧合下细胞周期的均一分布也导致了再氧合1小时与24小时的几乎相同的存活。而慢性无氧后CHO-K1细胞明显阻滞于G1期,而S期细胞比例明显下降,甚至缺乏；再氧合后的细胞周期分布在最初12小时变化非常快,并且在15-24小时时与有氧状态下细胞周期分布是可比的。同时,慢性无氧再氧合0,1小时的CHO-K1细胞和慢性无氧再氧合15小时下的细胞相比显示了对X线增加的放射敏感性。 结论：在X线和碳离子照射实验中,和急性无氧状态下相比,慢性无氧状况下细胞放射敏感性的增加及OER的减小,是由于慢性无氧引起的细胞周期G1阻滞及S期缺乏所引起的。和X线相比,碳离子显示了更为有效的杀伤,特别是对乏氧和无氧状态下的细胞。但是,和X线相比,本实验并未观察到碳离子照射可以减小慢性无氧所引起的细胞周期改变对存活的影响。
[Abstract]:Objective: it is known that hypoxia can directly or indirectly affect the physiological function of cells and lead to radiation resistance. In order to study the radiosensitivity of hypoxic cells to low linear energy transfer X-rays and high linear energy transfer carbon ion lines, The effects of the changes of cell cycle distribution on cell survival under chronic oxygen deficiency. X ray and medical high energy carbon ion line were used to study the radiative effects of Chinese hamster ovarian CHO-Kl cells under different hypoxia conditions. Cell clone survival and cell cycle distribution were measured. Materials and methods: CHO-K1 cells cultured under standard conditions were tested with oxygen (air), hypoxia (0.5) and oxygen (0.5) or anaerobic (95N _ 2 ~ (5) CO _ 2). In order to achieve acute anoxia or hypoxia, five specially designed hypoxic irradiating boxes were connected to gas cylinders, and the corresponding mixture gas (95N2CO _ 2 or 0.5% O _ 2N _ 2 94.5% nitrogen, 52) was replaced with 200 ml / min flow rate for 2 hours. After the acute hypoxia or hypoxia was reached, the hypoxia irradiation box was sealed and kept airtight for 24 hours, and the cells in the box reached chronic hypoxia or hypoxia. The reoxygenation experiment can be carried out by reexposing the cells in the hypoxia irradiation box to air for a certain time. 250kVp X ray and carbon ion ray were used to irradiate. The average linear energy of the carbon ions was transferred to 103keV/u m. The CHO-K1 cells were irradiated with the extended Bragg peak carbon ions of 1cm and cloned into CHO-K1 cells. Cell cycle changes were detected in anaerobic, hypoxic and chronic hypoxic or post-hypoxia reoxygenation conditions. Results: from the survival curves of different oxygen states, we can see that chronic hypoxia cells have very similar radiosensitivity to acute hypoxia. The cells with chronic hypoxia had higher radiosensitivity than those with acute hypoxia, and cells with 1 hour of chronic anaerobic reoxygenation also showed higher radiosensitivity to aerobic cells. This is found in both X-ray and C-ray irradiation. The detection of cell cycle distribution showed that the cell cycle distribution was quite uniform in hypoxic state, and the study of chronic hypoxia reoxygenation showed that the cell cycle changed homogeneously with time, and there was no significant difference between the cell cycle and aerobic cells. The homogeneous distribution of cell cycle under reoxygenation also resulted in almost the same survival at 1 hour and 24 h after reoxygenation. However, after chronic hypoxia, CHO-K1 cells were significantly blocked in G1 phase, while the proportion of S phase cells decreased significantly, and the cell cycle distribution after reoxygenation changed very rapidly at the first 12 hours. And the cell cycle distribution at 15-24 hours was comparable to that at aerobic state. At the same time, the radiosensitivity of CHO-K1 cells after 1 hour of chronic anaerobic reoxygenation and 15 hours of chronic anaerobic reoxygenation showed increased radiosensitivity to X-ray. Conclusion: the increase of radiosensitivity and the decrease of OER in chronic hypoxia are due to cell cycle G1 arrest and S phase deficiency. Compared with X-ray, carbon ion showed more effective killing, especially to cells in hypoxic and anoxic state. However, compared with X ray, it was not observed that carbon ion irradiation could reduce the effect of chronic hypoxia on cell cycle survival.
【学位授予单位】：复旦大学
【学位级别】：博士
【学位授予年份】：2012
【分类号】：R730.55
本文编号：2166978
[Abstract]:Objective: it is known that hypoxia can directly or indirectly affect the physiological function of cells and lead to radiation resistance. In order to study the radiosensitivity of hypoxic cells to low linear energy transfer X-rays and high linear energy transfer carbon ion lines, The effects of the changes of cell cycle distribution on cell survival under chronic oxygen deficiency. X ray and medical high energy carbon ion line were used to study the radiative effects of Chinese hamster ovarian CHO-Kl cells under different hypoxia conditions. Cell clone survival and cell cycle distribution were measured. Materials and methods: CHO-K1 cells cultured under standard conditions were tested with oxygen (air), hypoxia (0.5) and oxygen (0.5) or anaerobic (95N _ 2 ~ (5) CO _ 2). In order to achieve acute anoxia or hypoxia, five specially designed hypoxic irradiating boxes were connected to gas cylinders, and the corresponding mixture gas (95N2CO _ 2 or 0.5% O _ 2N _ 2 94.5% nitrogen, 52) was replaced with 200 ml / min flow rate for 2 hours. After the acute hypoxia or hypoxia was reached, the hypoxia irradiation box was sealed and kept airtight for 24 hours, and the cells in the box reached chronic hypoxia or hypoxia. The reoxygenation experiment can be carried out by reexposing the cells in the hypoxia irradiation box to air for a certain time. 250kVp X ray and carbon ion ray were used to irradiate. The average linear energy of the carbon ions was transferred to 103keV/u m. The CHO-K1 cells were irradiated with the extended Bragg peak carbon ions of 1cm and cloned into CHO-K1 cells. Cell cycle changes were detected in anaerobic, hypoxic and chronic hypoxic or post-hypoxia reoxygenation conditions. Results: from the survival curves of different oxygen states, we can see that chronic hypoxia cells have very similar radiosensitivity to acute hypoxia. The cells with chronic hypoxia had higher radiosensitivity than those with acute hypoxia, and cells with 1 hour of chronic anaerobic reoxygenation also showed higher radiosensitivity to aerobic cells. This is found in both X-ray and C-ray irradiation. The detection of cell cycle distribution showed that the cell cycle distribution was quite uniform in hypoxic state, and the study of chronic hypoxia reoxygenation showed that the cell cycle changed homogeneously with time, and there was no significant difference between the cell cycle and aerobic cells. The homogeneous distribution of cell cycle under reoxygenation also resulted in almost the same survival at 1 hour and 24 h after reoxygenation. However, after chronic hypoxia, CHO-K1 cells were significantly blocked in G1 phase, while the proportion of S phase cells decreased significantly, and the cell cycle distribution after reoxygenation changed very rapidly at the first 12 hours. And the cell cycle distribution at 15-24 hours was comparable to that at aerobic state. At the same time, the radiosensitivity of CHO-K1 cells after 1 hour of chronic anaerobic reoxygenation and 15 hours of chronic anaerobic reoxygenation showed increased radiosensitivity to X-ray. Conclusion: the increase of radiosensitivity and the decrease of OER in chronic hypoxia are due to cell cycle G1 arrest and S phase deficiency. Compared with X-ray, carbon ion showed more effective killing, especially to cells in hypoxic and anoxic state. However, compared with X ray, it was not observed that carbon ion irradiation could reduce the effect of chronic hypoxia on cell cycle survival.
【学位授予单位】：复旦大学
【学位级别】：博士
【学位授予年份】：2012
【分类号】：R730.55
【参考文献】
相关期刊论文 前2条
1 魏巍;李文建;郭传玲;荆西刚;金晓东;苏旭;;Effect of 80.55 MeV//u~(12)C~(6+) Ions on Radiosensitivity and Cell Cycle of Human Hepatoma Cell Lines[J];Plasma Science and Technology;2008年02期
2 ;Radiobiological response of human hepatoma and normal liver cells exposed to carbon ions generated by Heavy Ion Research Facility in Lanzhou[J];Science in China(Series G:Physics,Mechanics & Astronomy);2006年01期
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