Dahle J, Kaalhus O, Moan J, Steen H B
Department of Biophysics, Institute of Cancer Research, The Norwegian Radium Hospital, Oslo.
Proc Natl Acad Sci U S A. 1997 Mar 4;94(5):1773-8. doi: 10.1073/pnas.94.5.1773.
Microcolonies of 2-8 Madison-Darby canine kidney cells (MDCK II) and Chinese hamster lung fibroblasts (V79) cells were incubated with the photosensitizer Photofrin and exposed to light, and the resulting number of dead cells per colony was determined. The distribution of this number was found to be incompatible with the assumption that cells are inactivated independently. The experimental distributions were significantly different from the binomial distribution expected from this assumption, but in accordance with a model in which an inactivated cell can inactivate adjacent cells with a certain probability. These findings are contrary to the common view that damage caused by radiation is limited to the cell in which the primary damage takes place. Our findings clearly indicate some kind of cooperativity between cells treated with Photofrin and light.
将2 - 8个麦迪逊-达比犬肾细胞（MDCK II）和中国仓鼠肺成纤维细胞（V79）的微菌落与光敏剂卟吩姆钠一起孵育，然后进行光照，接着测定每个菌落中死亡细胞的数量。发现该数量的分布与细胞独立失活的假设不相符。实验分布与基于该假设预期的二项分布显著不同，但符合一种模型，即失活的细胞能够以一定概率使相邻细胞失活。这些发现与辐射造成的损伤仅限于发生初始损伤的细胞这一普遍观点相反。我们的发现清楚地表明，用卟吩姆钠和光照处理的细胞之间存在某种协同作用。
