Mitochondrial Determinants of Chemotherapy Responses in Cancer Cells

参与称为细胞凋亡的细胞死亡途径对于许多抗癌药物的成功至关重要，无论是新型靶向药物还是传统的细胞毒剂。无论化疗是传统的细胞毒性化疗，还是更现代的靶向治疗，通常情况下，虽然初始靶点已知，但将其连接到内在凋亡途径的靶点下游的信号却知之甚少。因此，化疗敏感性和耐药性的关键分子决定因素在很大程度上是未知的。其结果是，我们在预测肿瘤对化疗的反应和原因方面非常糟糕。因此，许多患者暴露在有毒药物中，没有很好的反应机会。在这里，我们提出了一种系统的方法，将药物与上游靶点的接触与线粒体程序性细胞死亡的承诺联系起来。由于bcl2蛋白家族是关键的调节因子 线粒体的凋亡，他们将被特别详细地研究。我们的目标是确定当肿瘤被抗有丝分裂药物或ABT-737杀死时调用的完整信号通路。我们将使用这些信息来生成预测模型，该模型可以仅基于某些已定义的初始条件来预测对治疗的敏感性。一旦这些预测模型在体外模型中得到验证，我们将应用于临床测试。此外，了解允许紫杉烷成功杀死的信号通路可能有助于识别该通路中可被毒性较低的药物选择性利用的靶点。 我们将使用的技术将包括对启动凋亡途径至关重要的基因的siRNA筛选。此外，我们还开发了一种新的策略，我们称之为基于FACS的BH3图谱，它允许我们在单细胞水平上观察细胞在向线粒体凋亡的过程中的死亡信号。这一策略将允许更详细地分析细胞周期的作用和单个分子在抗有丝分裂药物治疗后决定死亡的作用。

Engaging the cell death pathway known as apoptosis is critical for the success of many anti-cancer agents, both novel targeted agents and conventional cytotoxic agents. Whether the chemotherapy is conventional cytotoxic chemotherapy, or more modern targeted therapy, it is usually the case that while the initial target is known, the signaling downstream ofthe target that connects it to the intrinsic apoptotic pathway is poorly understood. Therefore, key molecular determinants of sensitivity and resistance to chemotherapy are largely unknown. The consequence, is that we are very bad at predicting what tumors respond to chemotherapy and why. Thus, many patients are exposed to toxic drugs without a good chance at response. Here we propose a systematic approach to connecting the contact of drug to upstream target to the commitment to programmed cell death at the mitochondrion. Since the BCL-2 family of proteins are the key regulators of mitochondrial apoptosis, they will be studied in particular detail. Our goals are to identify complete signaling pathways that are invoked when tumors are killed by anti-mitotic agents or ABT-737. We will use this information to generate predictive models that can predict sensitivity to treatment based solely on certain defined initial conditions. Once these predictive models are validated in in vitro models, we will apply to clinical testing. Furthermore, understanding the signaling pathways that permit successful killing by taxanes may permit the identification of targets in the pathway that can be selectively exploited by less toxic agents. The techniques we will use will include siRNA screening for genes that are essential for priming the apoptotic pathway. In addition, we have developed a new strategy which we call FACS-based BH3 profiling, that allows us to observe, at the single cell level, a cell's death signaling during progression to mitochondrial apoptosis. This strategy will permit a more detailed analysis ofthe role ofthe cell cycle and the role of individual molecules in determining death after treatment with anti-mitotic agents.