Bruchelt G, Girgert R, Buck J, Wolburg H, Niethammer D, Treuner J
Department of Pediatrics, University of Tuebingen, West Germany.
Cancer Res. 1988 Jun 1;48(11):2993-7.
As we have reported recently, the human neuroblastoma cell line SK-N-SH is able to take up and store m-iodobenzylguanidine (mIBG). This is in contrast to several other neuroblastoma cell lines, among which are SK-N-LO cells. Both cell lines were used in cell killing experiments with unlabeled and radioactive-labeled mIBG. Using 1-200 microCi m-[131I]IBG (1 h incubation time), only SK-N-SH cells could to a large extent be destroyed in a dose-dependent manner. This effect is completely caused by the radioactive labeling of the molecule, because unlabeled mIBG proved not to be toxic in the concentration range used in experiments with radiolabeled mIBG (30 nM-3 microM). The killing effect was strongly reduced when m-[131I]IBG with low specific activity (0.2-0.3 mCi/mg) was used instead of 20-30 mCi/mg. Similar effects in both cell lines were obtained using m-[131I]-and m-[125I]IBG. SK-N-SH cells that survived a first treatment with m-[131I]IBG were less sensitive to a second treatment. SK-N-LO cells were more sensitive against m-[131I]- and m-[125I]IBG than SK-N-SH cells if both cell lines are exposed to these radioactive compounds over a long period of time (24 h). The reason that only SK-N-SH cells could be destroyed in short-term incubation experiments is that mIBG is stored for approximately 7 days in these cells only. SK-N-LO cells could only be destroyed to a significant degree if m-[131I]IBG was permanently present in the test system. Bone marrow stem cells (CFU-c) also proved to be sensitive against m-[131I]IBG, although the effects were less pronounced than on SK-N-SH cells.
正如我们最近所报道的，人神经母细胞瘤细胞系SK-N-SH能够摄取并储存间碘苄胍（mIBG）。这与其他几种神经母细胞瘤细胞系不同，其中包括SK-N-LO细胞系。这两种细胞系都用于未标记和放射性标记的mIBG的细胞杀伤实验。使用1 - 200微居里的间-[131I]IBG（孵育时间1小时），只有SK-N-SH细胞能在很大程度上以剂量依赖的方式被破坏。这种效应完全是由该分子的放射性标记引起的，因为未标记的mIBG在放射性标记的mIBG实验中所用的浓度范围内（30 nM - 3 microM）被证明没有毒性。当使用比活度低（0.2 - 0.3毫居里/毫克）的间-[131I]IBG代替20 - 30毫居里/毫克的间-[131I]IBG时，杀伤效果显著降低。使用间-[131I] - 和间-[125I]IBG在两种细胞系中获得了类似的效果。经间-[131I]IBG首次处理后存活的SK-N-SH细胞对第二次处理的敏感性较低。如果将两种细胞系长时间（24小时）暴露于这些放射性化合物，SK-N-LO细胞比SK-N-SH细胞对间-[131I] - 和间-[125I]IBG更敏感。在短期孵育实验中只有SK-N-SH细胞能被破坏的原因是mIBG仅在这些细胞中储存约7天。只有当间-[131I]IBG在测试系统中持续存在时，SK-N-LO细胞才能被显著破坏。骨髓干细胞（CFU-c）也被证明对间-[131I]IBG敏感，尽管其效果不如对SK-N-SH细胞明显。
