Department of Biology, Georgia State University, Atlanta, 30303, USA.
Cell Death Differ. 2012 Aug;19(8):1255-67. doi: 10.1038/cdd.2012.61. Epub 2012 Jun 1.
Nearly a century ago, cell biologists postulated that the chromosomal aberrations blighting cancer cells might be caused by a mysterious organelle-the centrosome-that had only just been discovered. For years, however, this enigmatic structure was neglected in oncologic investigations and has only recently reemerged as a key suspect in tumorigenesis. A majority of cancer cells, unlike healthy cells, possess an amplified centrosome complement, which they manage to coalesce neatly at two spindle poles during mitosis. This clustering mechanism permits the cell to form a pseudo-bipolar mitotic spindle for segregation of sister chromatids. On rare occasions this mechanism fails, resulting in declustered centrosomes and the assembly of a multipolar spindle. Spindle multipolarity consigns the cell to an almost certain fate of mitotic arrest or death. The catastrophic nature of multipolarity has attracted efforts to develop drugs that can induce declustering in cancer cells. Such chemotherapeutics would theoretically spare healthy cells, whose normal centrosome complement should preclude multipolar spindle formation. In search of the 'Holy Grail' of nontoxic, cancer cell-selective, and superiorly efficacious chemotherapy, research is underway to elucidate the underpinnings of centrosome clustering mechanisms. Here, we detail the progress made towards that end, highlighting seminal work and suggesting directions for future research, aimed at demystifying this riddling cellular tactic and exploiting it for chemotherapeutic purposes. We also propose a model to highlight the integral role of microtubule dynamicity and the delicate balance of forces on which cancer cells rely for effective centrosome clustering. Finally, we provide insights regarding how perturbation of this balance may pave an inroad for inducing lethal centrosome dispersal and death selectively in cancer cells.
近一个世纪前,细胞生物学家假设,破坏癌细胞的染色体异常可能是由一个神秘的细胞器——中心体——引起的,而这个细胞器刚刚被发现。然而,多年来,这个神秘的结构在肿瘤学研究中被忽视了,直到最近才重新成为肿瘤发生的关键嫌疑犯。与健康细胞不同,大多数癌细胞拥有扩增的中心体补充物,它们在有丝分裂期间设法整齐地聚集在两个纺锤体极上。这种聚类机制允许细胞形成一个伪双极有丝分裂纺锤体,用于姐妹染色单体的分离。在极少数情况下,这种机制会失败,导致中心体去聚类,并组装出多极纺锤体。纺锤体的多极性将细胞推向有丝分裂停滞或死亡的几乎确定命运。多极性的灾难性性质促使人们努力开发能够诱导癌细胞去聚类的药物。从理论上讲,这种化疗药物可以避免健康细胞受到影响,因为健康细胞的正常中心体补充物应该可以防止多极纺锤体的形成。为了寻找非毒性、癌细胞选择性和高效的化疗的“圣杯”,人们正在进行研究,以阐明中心体聚类机制的基础。在这里,我们详细介绍了为此所做的进展,重点介绍了开创性的工作,并提出了未来研究的方向,旨在揭开这个棘手的细胞策略,并将其用于化疗目的。我们还提出了一个模型,突出了微管动态性和癌细胞赖以有效聚类中心体的力量微妙平衡的整体作用。最后,我们提供了一些关于如何扰乱这种平衡可能为选择性诱导癌细胞致命的中心体分散和死亡开辟途径的见解。