Antoku S, Kura S
Department of Experimental Radiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Int J Radiat Biol. 1990 Oct;58(4):613-22. doi: 10.1080/09553009014551971.
The enhancement of radiosensitivity by neocarzinostatin (NCS), an antitumour drug, was studied using three strains of cultured mammalian cells with different repair capabilities for sublethal damage. NCS enhanced the radiosensitivity of the cells when applied both during and after X-irradiation under aerobic conditions. The enhancement ratios of NCS during X-irradiation were 1.25, 1.27 and 1.38 for mouse lymphoma L5178Y, Chinese hamster V79 and mouse mammary tumour FM 3A cells, respectively. The corresponding ratios after X-irradiation were 1.18, 1.27 and 1.38, respectively. These ratios were proportional to the repair capabilities of the cells for sublethal damage. NCS completely inhibited the repair of sublethal damage regardless of the repair capabilities of the cells for sublethal damage. NCS was equally effective for hypoxic cells. These results suggested that NCS enhanced the radiosensitivity of the cells probably by interacting with the residual damage after X-irradiation, thereby converting the sublethal damage or potentially lethal damage into lethal damage.
使用三种对亚致死损伤具有不同修复能力的培养哺乳动物细胞系，研究了抗肿瘤药物新制癌菌素（NCS）对放射敏感性的增强作用。在有氧条件下，当在X射线照射期间及照射后应用NCS时，其增强了细胞的放射敏感性。对于小鼠淋巴瘤L5178Y、中国仓鼠V79和小鼠乳腺肿瘤FM 3A细胞，在X射线照射期间NCS的增强倍数分别为1.25、1.27和1.38。X射线照射后相应的倍数分别为1.18、1.27和1.38。这些倍数与细胞对亚致死损伤的修复能力成比例。无论细胞对亚致死损伤的修复能力如何，NCS均完全抑制亚致死损伤的修复。NCS对缺氧细胞同样有效。这些结果表明，NCS可能通过与X射线照射后的残余损伤相互作用来增强细胞的放射敏感性，从而将亚致死损伤或潜在致死损伤转化为致死损伤。
