Photodynamic killing of retinoblastoma cells with hematoporphyrin and light.
Photodynamic killing of retinoblastoma cells with hematoporphyrin and light.
复制标题
用血卟啉和光光动力杀死视网膜母细胞瘤细胞。
作者：
T. Sery
血卟啉和白色光对两种视网膜母细胞瘤细胞系具有致死作用。能够杀死整个细胞群的染料浓度和光暴露的最低值分别为2 × 10（-5）M和6.0微瓦/平方毫米的辐照度下暴露6分钟。在染料存在下暴露于光的细胞不需要长时间的孵育期，但随着光暴露时间的增加而迅速杀死。然而，不含染料的细胞需要3.5小时的最小敏化期以达到接近100%细胞死亡的值。在正常血清中证明了这种光动力过程的抑制剂。当胎牛血清、兔血清或兔血浆的浓度从标准的10%增加到25%时，产生相同的致死反应所需的血卟啉浓度增加了100倍。对这种现象的解释是卟啉结合血浆因子，血红素结合蛋白，它是一种天然的β-糖蛋白，被认为负责将循环卟啉转运到肝脏以消除它们。视网膜母细胞瘤细胞在悬浮液中生长，从而为光敏染料的研究提供了极好的工具，特别是在快速生长的Y 79细胞系的情况下。
Hematoporphyrin and white light exerted a lethal effect on two cell lines of retinoblastoma cells. The lowest values of dye concentration and light exposure capable of killing an entire cell population were, respectively, 2 X 10(-5) M and 6 min exposure to an irradiance of 6.0 microwatts/sq mm. Cells exposed to light in the presence of the dye did not require lengthy incubation periods but were rapidly killed with increasing periods of light exposure. Cells washed free of the dye, however, required a minimum sensitizing period of 3.5 hr to achieve a value close to 100% cell death. An inhibitor of this photodynamic process was demonstrated in normal serum. When the concentration of either fetal calf serum, rabbit serum, or rabbit plasma was increased to 25% from a standard 10%, there was as much as a 100-fold greater requirement of hematoporphyrin concentration to produce the same lethal response. The suggested explanation for this phenomenon is a porphyrin-binding plasma factor, hemopexin, which is a natural beta-glycoprotein believed to be responsible for the transport of circulating porphyrins to the liver for their elimination. Retinoblastoma cells grow in suspension and thereby provide an excellent tool for study of photosensitive dyes, especially in the case of the rapidly growing Y79 cell line.