Duensing A, Liu Y, Tseng M, Malumbres M, Barbacid M, Duensing S
Department of Pathology, University of Pittsburgh School of Medicine, PA 15213, USA.
Oncogene. 2006 May 11;25(20):2943-9. doi: 10.1038/sj.onc.1209310.
Cyclin-dependent kinase 2 (CDK2) has been proposed to function as a master regulator of centrosome duplication. Using mouse embryonic fibroblasts (MEFs) in which Cdk2 has been genetically deleted, we show here that CDK2 is not required for normal centrosome duplication, maturation and bipolar mitotic spindle formation. In contrast, Cdk2 deficiency completely abrogates aberrant centrosome duplication induced by a viral oncogene. Mechanistically, centrosome overduplication in MEFs wild-type for Cdk2 involves the formation of supernumerary immature centrosomes. These results indicate that normal and abnormal centrosome duplication have significantly different requirements for CDK2 activity and point to a role of CDK2 in licensing centrosomes for aberrant duplication. Furthermore, our findings suggest that CDK2 may be a suitable therapeutic target to inhibit centrosome-mediated chromosomal instability in tumor cells.
细胞周期蛋白依赖性激酶2(CDK2)被认为是中心体复制的主要调节因子。我们利用基因敲除Cdk2的小鼠胚胎成纤维细胞(MEF),证明了正常的中心体复制、成熟和双极有丝分裂纺锤体形成并不需要CDK2。相反,Cdk2缺陷完全消除了病毒癌基因诱导的异常中心体复制。从机制上讲,在Cdk2野生型的MEF中,中心体过度复制涉及形成多余的未成熟中心体。这些结果表明,正常和异常的中心体复制对CDK2活性有显著不同的要求,并指出CDK2在许可中心体异常复制中发挥作用。此外,我们的研究结果表明,CDK2可能是抑制肿瘤细胞中中心体介导的染色体不稳定性的合适治疗靶点。