Friedkin M, Crawford E J
Exp Cell Res. 1983 Oct 15;148(2):520-4. doi: 10.1016/0014-4827(83)90174-x.
By immunofluorescent staining to visualize the cytoplasmic microtubular cytoskeleton in mouse fibroblasts we have ascertained that after a relatively short exposure of cells to colchicine, microtubules remain disassembled for a prolonged period of time after cells are transferred to a colchicine-free medium. In contrast to the persisting effects of colchicine, a brief exposure of cells to nocodazole first induces the expected disruption of microtubules followed by regeneration of the cytoskeleton within a few hours after removal of extracellular drug. These results shed light on our previous finding that quiescent mouse fibroblasts first treated with colchicine and then transferred to colchicine-free medium exhibit an enhanced proliferative response to EGF and insulin, whereas cells treated in a similar manner with nocodazole show no enhancement of DNA synthesis stimulated by peptide growth hormones. We conclude that cytoplasmic microtubules must remain disaggregated during the prereplicative G1 period in order for cells to exhibit the enhancing effects of the microtubule-disrupting drugs on DNA synthesis.
通过免疫荧光染色来观察小鼠成纤维细胞中的细胞质微管细胞骨架，我们已确定，在细胞相对短时间暴露于秋水仙碱后，当细胞转移至不含秋水仙碱的培养基中时，微管在较长一段时间内仍保持解聚状态。与秋水仙碱的持续作用相反，细胞短暂暴露于诺考达唑首先会导致预期的微管破坏，随后在去除细胞外药物后的数小时内细胞骨架会再生。这些结果揭示了我们之前的发现，即先经秋水仙碱处理然后转移至不含秋水仙碱培养基中的静止小鼠成纤维细胞，对表皮生长因子（EGF）和胰岛素表现出增强的增殖反应，而以类似方式用诺考达唑处理的细胞，在肽生长激素刺激下DNA合成并未增强。我们得出结论，为使细胞表现出微管破坏药物对DNA合成的增强作用，细胞质微管在复制前的G1期必须保持解聚状态。
