Antoku S, Kura S
Department of Experimental Radiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Int J Radiat Biol. 1990 Oct;58(4):623-32. doi: 10.1080/09553009014551981.
The effects of neocarzinostatin (NCS), an anti-tumour drug, on the repair of potentially lethal damage (PLD) were studied using cultured Chinese hamster V79, malignant human melanoma and mouse lymphoma L5178Y cells in the stationary phase. The repair of PLD was observed in the melanoma and L5178Y cells but no such repair was observed in the V79 cells, when studied by delayed plating. NCS added to the culture medium immediately after X-irradiation evoked fixation of PLD within 10 min of the addition of NCS. The ratios of D0 values of the survival curves of the cells treated with NCS to those plated immediately after X-irradiation were 0.78, 0.88 and 0.85 for V79, melanoma and L5178Y cells, respectively. The extent of the fixation by NCS was similar to that caused by 0.5 M NaCl solution. The results in the present study and the inhibition of sublethal damage (SLD) by NCS reported previously, suggest that NCS might react with the DNA damage induced by radiation and modify it to lethal damage. The study indicates that SLD and PLD appear to be closely related to one another.
利用处于静止期的中国仓鼠V79细胞、人恶性黑色素瘤细胞和小鼠淋巴瘤L5178Y细胞，研究了抗肿瘤药物新制癌菌素（NCS）对潜在致死性损伤（PLD）修复的影响。通过延迟接种法研究发现，黑色素瘤细胞和L5178Y细胞中可观察到PLD的修复，但V79细胞中未观察到这种修复。X射线照射后立即向培养基中添加NCS，在添加NCS后10分钟内可诱导PLD的固定。对于V79细胞、黑色素瘤细胞和L5178Y细胞，用NCS处理的细胞存活曲线的D0值与X射线照射后立即接种的细胞的D0值之比分别为0.78、0.88和0.85。NCS诱导固定的程度与0.5 M NaCl溶液引起的程度相似。本研究结果以及先前报道的NCS对亚致死性损伤（SLD）的抑制作用表明，NCS可能与辐射诱导的DNA损伤发生反应并将其转化为致死性损伤。该研究表明，SLD和PLD似乎密切相关。
