Parameters that determine cell fate during mitotic arrest

有丝分裂纺锤体破坏导致纺锤体组装检查点（SAC）激活延长 可导致p53激活、中心粒脱离和细胞死亡。果然 常用于侵袭性和非依赖性癌症的化疗策略 是靶向有丝分裂纺锤体，一种基于微管的结构， 染色体分离和细胞分裂。长春碱或紫杉醇等药物抑制 正常的微管组装动力学，导致有丝分裂停滞和最终的细胞死亡， 凋亡然而，尽管在临床上实施了数十年， 延长的有丝分裂延迟导致细胞死亡仍不清楚。此外，尽管 尽管有丝分裂纺锤体对细胞分裂的要求具有普遍性，但仍然存在大量的 细胞如何对纺锤体破坏作出反应的异质性，这可能会降低抗- 有丝分裂化疗策略。结合生物化学和活细胞成像 我们的初步数据显示，靶向驱动蛋白纺锤体蛋白（KSP）， 纺锤体双极性所需的分子马达和磷脂酰肌醇3-激酶 （PI 3 K）/Akt/mTOR信号通路显著加速有丝分裂细胞死亡的动力学 相对于单独的有丝分裂停滞。此外，它还使人们的反应更加均匀， 处理的细胞。PI 3 K信号通路参与多种调节细胞凋亡的途径， 存活、代谢和增殖，但PI 3 K活性促进细胞增殖的机制 有丝分裂停滞期间的活力是未知的。为了更好地了解PI 3 K信号是如何参与 细胞死亡的时间和有丝分裂延迟的细胞反应的可变性，我们将继续 应用高通量时移成像、高分辨率4D成像和生物化学 获得一组细胞系的方法在它们对有丝分裂延迟的敏感性以及 依赖PI 3 K信号。该项目的具体目标是：1）确定保护性 PI 3 K在正常细胞和癌细胞中的作用;和2）确定PI 3 K 在有丝分裂延迟期间促进细胞存活。如果成功，这些研究将为 未来的转化研究，以进一步开发靶向有丝分裂活性的辅助疗法， 肿瘤细胞，而没有与其他微管破坏剂相关的副作用。

Prolonged activation of the spindle assembly checkpoint (SAC) due to mitotic spindle disruption can result in p53 activation, centriole disengagement and cell death. Indeed, one chemotherapeutic strategy frequently applied to aggressive and hormone-independent cancers is to target the mitotic spindle, a microtubule-based structure that is required for proper chromosome segregation and cell division. Drugs such as vinblastine or Paciltaxel suppress the normal microtubule assembly dynamics, leading to mitotic arrest and eventual cell death by apoptosis. However, despite their decades-long implementation in the clinic, the mechanisms by which prolonged mitotic delay results in cell death remains unclear. Further, despite the universality of the requirement of the mitotic spindle for cell division, there is still a great deal of heterogeneity in how cells respond to spindle disruption, which may reduce the efficacy of anti- mitotic chemotherapeutic strategies. Using a combination of biochemical and live cell imaging approaches, our preliminary data reveals that targeting both Kinesin Spindle Protein (KSP), a molecular motor required for spindle bipolarity, and the Phosphatidylinositide 3-kinase (PI3K)/Akt/mTOR signaling pathway dramatically accelerates the kinetics of mitotic cell death relative to mitotic arrest alone. Moreover, it elicits a more homogeneous response from the treated cells. PI3K signaling is involved in a variety of regulatory pathways that regulate cell survival, metabolism and proliferation, but the mechanism by which PI3K activity promotes cell viability during mitotic arrest is unknown. To better understand how PI3K signaling is involved in the timing of cell death and variability of cellular responses of mitotic delay, we will continue to apply high-throughput timelapse imaging, high-resolution 4D imaging and biochemical approaches to a battery of cell lines differ in their sensitivity to mitotic delay as well as dependence on PI3K signaling. The Specific Aims of this project will 1) Define the protective role of PI3K in normal and cancer cells; and 2) Determine the mechanism by which PI3K promotes cell survival during mitotic delay. If successful, these studies will lay the foundation for future translational studies to further develop adjuvant therapies that will target mitotically active tumor cells without the side effects associated with other microtubule disruptors.