SB225002 Promotes Mitotic Catastrophe in Chemo-Sensitive and -Resistant Ovarian Cancer Cells Independent of p53 Status In Vitro
SB225002 Promotes Mitotic Catastrophe in Chemo-Sensitive and -Resistant Ovarian Cancer Cells Independent of p53 Status In Vitro
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SB225002 在体外促进化疗敏感和耐药的卵巢癌细胞有丝分裂灾难，与 p53 状态无关
DOI：
10.1371/journal.pone.0054572
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发表时间：
2013-01-24
期刊：
影响因子：
3.7
通讯作者：
Tsang, Benjamin K.
中科院分区：
文献类型：
--
作者：
Du, Meirong;Qiu, Qing;Tsang, Benjamin K.
最近的证据表明，CXCR 2信号传导对癌症进展至关重要，其拮抗剂SB 225002诱导Wilms肿瘤细胞凋亡。在这里，我们研究了SB 225002在体外对细胞周期进程和凋亡诱导的影响，使用CDDP敏感和耐药OVCA细胞系与不同的p53状态（野生型，突变体或空）。使用腺病毒感染野生型p53或转染p53 siRNA来过表达或敲低p53。流式细胞术或Hoechst染色法检测细胞周期和凋亡，并观察细胞核形态。我们的数据表明，SB 225002通过替代机制诱导野生型和p53缺陷型卵巢癌（OVCA）细胞凋亡。SB 225002促进有丝分裂灾难，如通过具有纺锤体异常、染色体错误分离、多极细胞分裂、多核、非整倍体/多倍体和随后的广泛凋亡的有丝分裂细胞的积累所证明的。SB 225002诱导的有丝分裂灾难似乎是通过下调检查点激酶Chk 1和Cdk 1-cyclin B激活介导的。在表达野生型p53（OV 2008和C13*）的细胞中，SB 225002增加了总的和磷酸化丝氨酸p53水平，p53敲低降低了SB 225002诱导的细胞凋亡，而不影响过早的有丝分裂。这些结果表明，SB 225002诱导p53依赖性凋亡，并在p53野生型细胞中以p53非依赖性方式引发有丝分裂灾难。在P53缺失的SKOV 3细胞中用野生型P53重建减弱了SB 225002诱导的有丝分裂灾难，表明p53在p53缺失的OVCA细胞中阻止了SB 225002诱导的有丝分裂灾难。最后，SB 225002的作用不能被CXCR 2配体或其中和抗体预处理所阻止。本研究首次证明，SB 225002在OVCA细胞中具有双重作用，通过p53激活诱导经典凋亡，并通过Chk 1抑制和Cdk激活在p53野生型和缺陷细胞中引发有丝分裂灾难。这些发现提高了SB 225002作为独立于p53状态的OVCA治疗的新候选分子的可能性。
Recent evidence indicates that CXCR2 signaling is crucial for cancer progression, and its antagonist SB225002 induces apoptosis in Wilms' tumor cells. Here, we investigated the effect of SB225002 on cell cycle progression and apoptosis induction in vitro, using CDDP-sensitive and -resistant OVCA cell lines with different p53 status (wild type, mutant or null). Adenovirus infection of wild-type p53 or transfection of p53 siRNA was used to over-express or knock-down p53. Cell cycle and apoptosis were determined by flow cytometry or Hoechst staining and observation of nuclear morphology. Our data demonstrated that SB225002 induced apoptosis in both wild-type and p53-deficient ovarian cancer (OVCA) cells through alternative mechanisms. SB225002 promoted mitotic catastrophe, as evidenced by the accumulation of mitotic cells with spindle abnormalities, chromosome mis-segregation, multi-polar cell division, multiple nuclei, aneuploidy/polyploidy and subsequent extensive apoptosis. SB225002-induced mitotic catastrophe appeared to be mediated by down-regulation of checkpoint kinase Chk1 and Cdk1-cyclin B activation. In cells expressing wild-type p53 (OV2008 and C13*), SB225002 increased total and phospho-Ser p53 levels, and p53 knock-down decreased SB225002-induced apoptosis, without affecting premature mitosis. These results suggest that SB225002 induces p53-dependent apoptosis, and provokes mitotic catastrophe in p53-independent manner in p53 wild-type cells. Reconstitution with wild-type P53 in P53-null SKOV3 cell attenuated SB225002-induced mitotic catastrophe, suggesting p53 prevented mitotic catastrophe induced by SB225002 in p53-deficient OVCA cells. Finally, the effect of SB225002 could not be prevented by pretreatment with CXCR2 ligand or its neutralizing antibody. The present studies demonstrate for the first time that SB225002 has dual actions in OVCA cells, inducing classic apoptosis through p53 activation and provoking mitotic catastrophe in both p53 wild-type and deficient cells by Chk1 inhibition and Cdk activation. These findings raise the possibility of SB225002 as a new candidate molecule for OVCA therapy independent of the p53 status.