Pulse treatment of interphasic HeLa cells with nanomolar doses of docetaxel affects centrosome organization and leads to catastrophic exit of mitosis.
Pulse treatment of interphasic HeLa cells with nanomolar doses of docetaxel affects centrosome organization and leads to catastrophic exit of mitosis.
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发表时间：
1997-10
影响因子：
4
通讯作者：
A. Paoletti;N. Giocanti;V. Favaudon;M. Bornens
中科院分区：
文献类型：
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作者：
A. Paoletti;N. Giocanti;V. Favaudon;M. Bornens
为了研究中心体复制在有丝分裂纺锤体形态发生中的作用，我们设计了一种对同步 HeLa 细胞使用纳摩尔剂量的紫杉烷进行 1 小时脉冲处理的方案，该方案可能会损害中心体的生物发生，但会允许在有丝分裂前恢复正常的微管 (Mt) 动力学。我们被提示使用这种方法，因为多西紫杉醇（DOC；taxotereTM）是一种已知促进 Mt 聚合的紫杉醇，在 S 期使用时显示出更强的细胞毒性。我们表明，脉冲药物暴露在 S 晚期和 G2 中最有效，并导致 G2 中中心体显着解体，中心粒周围材料 (PCM) 从中心粒解离。 G2-M 转变时中心体的分离也受到损害，有丝分裂纺锤体形态发生严重异常：尽管在大多数纺锤体中染色体在中期板中对齐，但两个中心体通常在一个极处保持不分离，而大多数 NuMA 蛋白在另一极积累。有趣的是，我们发现中心体的复制能力并没有被消除，因为它们仍然能够触发青蛙卵的孤雌发育。尽管纺锤体不对称，但有丝分裂的进展并未受阻。这导致有丝分裂的灾难性退出，每个有丝分裂细胞产生几个由多个中间体连接在一起的微核细胞。因此，缺乏有丝分裂阻断似乎是细胞致死的主要原因。这些实验表明，有丝分裂开始时的 NuMA 重新分布取决于中心粒对之间 PCM 的正确重新分布。他们还表明，异常纺锤体极的存在不会提醒控制有丝分裂退出的监视机制。
In order to investigate the role of centrosome duplication in mitotic spindle morphogenesis, we designed a 1 hour pulse treatment protocol on synchronized HeLa cells with nanomolar doses of taxoids that might impair centrosome biogenesis but would allow the recovery of normal microtubule (Mt) dynamics before mitosis. We were prompted to use this approach as docetaxel (DOC; taxotereTM), a taxoid known to promote Mt polymerization, was shown to be more cytotoxic when applied during S phase. We show that pulse drug exposure is most efficient in late S and in G2 and results in a marked disorganization of the centrosome in G2, the pericentriolar material (PCM) being dissociated from centrioles. Separation of centrosomes at the G2-M transition is also impaired and mitotic spindle morphogenesis is grossly abnormal: although in most spindles chromosomes align in a metaphase plate, the two centrosomes stay most often unseparated at one pole and most of the NuMA protein accumulates at the other. Interestingly, we find that the centrosomes' ability to duplicate is not abolished as they are still able to trigger parthenogenetic development of frog eggs. Despite spindle asymmetry, the progression through mitosis is not blocked. This results in a catastrophic exit from mitosis, each mitotic cell generating several micronucleated cells linked together by multiple midbodies. Lack of mitotic block appears therefore as the prime cause of cell lethality. These experiments suggest that NuMA redistribution at the onset of mitosis depends upon the correct redistribution of PCM between centriole pairs. They also indicate that the presence of aberrant spindle poles does not alert the surveillance mechanism controlling the exit of mitosis.