Paclitaxel-dependent cell lines reveal a novel drug activity.
Paclitaxel-dependent cell lines reveal a novel drug activity.
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DOI：
10.1158/1535-7163.mct-10-0552
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发表时间：
2010-11
影响因子：
5.7
通讯作者：
Cabral F
中科院分区：
文献类型：
--
作者：
Ganguly A;Yang H;Cabral F
我们先前描述了Tax 18和Tax 11-6的分离，Tax 18和Tax 11-6是两种紫杉醇依赖性细胞系，其组装少量微管聚合物并需要药物用于细胞分裂。在本研究中，荧光延时显微镜被用来测量微管在这些细胞的动态不稳定行为。这些突变导致微管生长和缩短的小幅减少，但这些变化似乎无法解释微管聚合物水平或细胞分裂的缺陷。此外，紫杉醇在低药物浓度下进一步抑制微管动力学，这不足以挽救突变表型。用类似的低药物浓度处理的野生型细胞也具有高度抑制的微管，但细胞分裂没有问题。因此，紫杉醇对微管动力学的影响似乎与野生型和突变细胞系中的细胞分裂无关。拯救突变体表型所需的较高药物浓度反而抑制了不稳定微管片段的形成，这些片段在药物依赖性细胞系中以高频率出现，但在野生型细胞系中则不然。活细胞成像显示，这些片段是由微管从中心体脱离产生的，紫杉醇逆转了这一过程。我们的结论是，紫杉醇拯救突变细胞分裂抑制微管负端从中心体的分离，而不是通过改变正端微管动力学。
We previously described the isolation of Tax 18 and Tax 11-6, two paclitaxel dependent cell lines that assemble low amounts of microtubule polymer and require the drug for cell division. In the present studies, fluorescence time-lapse microscopy was used to measure microtubule dynamic instability behavior in these cells. The mutations were found to cause small decreases in microtubule growth and shortening, but the changes appeared unable to explain the defects in microtubule polymer levels or cell division. Moreover, paclitaxel further suppressed microtubule dynamics at low drug concentrations that were insufficient to rescue the mutant phenotype. Wild-type cells treated with similar low drug concentrations also had highly suppressed microtubules, yet experienced no problems with cell division. Thus, the effects of paclitaxel on microtubule dynamics appeared to be unrelated to cell division in both wild-type and mutant cell lines. The higher drug concentrations needed to rescue the mutant phenotype instead inhibited the formation of unstable microtubule fragments that appeared at high frequency in the drug dependent, but not wild-type, cell lines. Live cell imaging revealed that the fragments were generated by microtubule detachment from centrosomes, a process that was reversed by paclitaxel. We conclude that paclitaxel rescues mutant cell division by inhibiting the detachment of microtubule minus-ends from centrosomes rather than by altering plus-end microtubule dynamics.