Radiosensitization with 5-bromodeoxyuridine of Chinese hamster cells x-irradiated during different phases of the cell cycle.
Radiosensitization with 5-bromodeoxyuridine of Chinese hamster cells x-irradiated during different phases of the cell cycle.
复制标题
在细胞周期的不同阶段对经过 X 射线照射的中国仓鼠细胞进行 5-溴脱氧尿苷的放射增敏。
作者：
W. Dewey;L. E. Stone;H. H. Miller;R. Giblak
杜威，W. C.的方法，斯通湖E、米勒，H。H、吉布拉克河E. 5-溴脱氧尿苷对X线照射后中国人鼻咽癌细胞周期不同时期的放射增敏作用Radiat. Res. 47，672-688（1971）中所述。通过从体外生长的异步群体中选择有丝分裂细胞来同步化细胞，对细胞进行X射线照射，然后分析致死率和染色体畸变。当BUdR掺入发生照射后，没有观察到放射增敏或协同作用，虽然BUdR治疗产生了一个小的累加效应。然而，当细胞在有丝分裂同步化之前掺入BUdR至少一个周期时，获得一定量损伤所需的辐射剂量减少了1.9倍（BUdR增强比）。当细胞在有丝分裂期、G1期或S期受到辐照时，在染色体畸变和细胞致死率方面观察到BUdR增强率。对于两个损伤终点，有丝分裂期最敏感，呈线性剂量-效应反应，G1期敏感性居中（与有丝分裂细胞相比，剂量修正因子为1.5-2.0），剂量-效应曲线上有一个小肩，S期最耐药（与有丝分裂细胞相比，剂量修正因子为2.1-3.2），剂量-效应曲线上有一个较大的肩。此外，对于未处理和BUdR处理的细胞，在有丝分裂、G1或S中照射，存活对数与畸变频率线性相关（当细胞维持0.75畸变/细胞时，存活率为37%）。这些关系为X射线诱导的细胞死亡是由染色体畸变引起的假说提供了相当大的支持。
DEWEY, W. C., STONE, L. E., MILLER, H. H., AND GIBLAK, R. E. Radiosensitization with 5-Bromodeoxyuridine of Chinese Hamster Cells X-Irradiated During Different Phases of the Cell Cycle. Radiat. Res. 47, 672-688 (1971). Cells synchronized by selecting mitotic cells from an asynchronous population growing in vitro, were x-irradiated and then analyzed both for lethality and for chromosomal aberrations. When BUdR incorporation occurred following irradiation, no radiosensitization or synergistic interaction was observed, although the BUdR treatment produced a small additive effect. However, when the cells incorporated BUdR for at least one cycle prior to being synchronized in mitosis, the radiation dose required to obtain a certain amount of damage was reduced by a factor of 1.9 (BUdR enhancement ratio). This BUdR enhancement ratio was observed in terms of both chromosomal aberrations and cell lethality when cells were irradiated either in mitosis, G1, or S. For both end points of damage, the mitotic phase was most sensitive with a linear dose-effect response, the G1 phase was intermediate in sensitivity (dose modifying factors of 1.5-2.0 compared with mitotic cells) with a small shoulder on the dose-effect curve, and the S phase was most resistant (dose modifying factors of 2.1-3.2 compared with mitotic cells) with a large shoulder on the dose-effect curve. Furthermore, for both untreated and BUdRtreated cells, irradiated either in mitosis, G1, or S, the logarithm of survival was linearly related to the aberration frequency (37 % survival occurring when the cells sustained 0.75 aberrations per cell). These relationships add considerable support to the hypothesis that x-rayinduced cell death results from a chromosomal aberration.