Ecole Polytechnique Fédérale de Lausanne (EPFL), Swiss Institute for Experimental Cancer Research (ISREC), 1015 Lausanne, Switzerland.
Virology. 2010 May 10;400(2):271-86. doi: 10.1016/j.virol.2010.02.003. Epub 2010 Mar 2.
Adeno-associated virus (AAV) type 2 or UV-inactivated AAV (UV-AAV2) infection provokes a DNA damage response that leads to cell cycle arrest at the G2/M border. p53-deficient cells cannot sustain the G2 arrest, enter prolonged impaired mitosis, and die. Here, we studied how non-replicating AAV2 kills p53-deficient osteosarcoma cells. We found that the virus uncouples centriole duplication from the cell cycle, inducing centrosome overamplification that is dependent on Chk1, ATR and CDK kinases, and on G2 arrest. Interference with spindle checkpoint components Mad2 and BubR1 revealed unexpectedly that mitotic catastrophe occurs independently of spindle checkpoint function. We conclude that, in the p53-deficient cells, UV-AAV2 triggers mitotic catastrophe associated with a dramatic Chk1-dependent overduplication of centrioles and the consequent formation of multiple spindle poles in mitosis. As AAV2 acts through cellular damage response pathways, the results provide information on the role of Chk1 in mitotic catastrophe after DNA damage signaling in general.
腺相关病毒（AAV）2 型或紫外线失活的 AAV（UV-AAV2）感染会引发 DNA 损伤反应，导致细胞在 G2/M 交界处停滞。p53 缺陷细胞无法维持 G2 期阻滞，进入长时间受损的有丝分裂，并死亡。在这里，我们研究了非复制型 AAV2 如何杀死 p53 缺陷型骨肉瘤细胞。我们发现，该病毒将中心体复制与细胞周期脱偶联，诱导中心体过度扩增，这依赖于 Chk1、ATR 和 CDK 激酶以及 G2 期阻滞。干扰纺锤体检查点成分 Mad2 和 BubR1 出人意料地表明，有丝分裂灾难的发生独立于纺锤体检查点功能。我们的结论是，在 p53 缺陷细胞中，UV-AAV2 引发有丝分裂灾难，与 Chk1 依赖性中心体过度复制以及随后在有丝分裂中形成多个纺锤体极有关。由于 AAV2 通过细胞损伤反应途径发挥作用，因此这些结果提供了有关 Chk1 在一般 DNA 损伤信号转导后有丝分裂灾难中的作用的信息。
