Probing mitochondria and personalizing leukemia therapy with BH3 profiling

描述（由申请人提供）：随着慢性淋巴细胞白血病（CLL）中正在测试的疗法越来越多，为每个患者确定哪种疗法是最好的挑战越来越大。在这个有竞争力的更新提案中，我们提出了确定单个CLL肿瘤治疗机会的策略。这种方法的一个关键要素是预测患者对个体疗法的反应的能力。我们应用了我们在最初的资助期学到的关于细胞凋亡控制的许多基本经验教训，并利用了我们在该提案中改进的工具，BH 3分析。基于我们先前的工作，我们发现我们可以将体外对ABT-737的敏感性与BH 3谱结果相关联，我们提出测试我们预测CLL中对相关BCL-2拮抗剂ABT-199的临床反应的能力（具体目标#1）。此外，在具体目标#2中，我们建议在CLL的个体病例中识别通路成瘾。在过去，siRNA和shRNA方法的效率低下以及CLL中离体培养的困难使得该问题难以通过常规手段解决。我们提出了一项研究，使用小分子途径抑制剂，而不是敲低策略，以逃避RNA转染的困难。重要的是，我们使用BH 3谱来测量药物治疗的4-24小时内的早期凋亡信号传导，从而避免了对延长的离体培养的需要。我们的目标是将响应小分子抑制剂的早期凋亡信号与通路成瘾联系起来。这种方法的一个重要优点是，检测原发性CLL中响应于药物的凋亡信号传导为临床转化提供了合理的途径。最后，在具体目标#3中，我们 提出研究基质相互作用如何抑制CLL细胞凋亡信号。此外，使用体外共培养系统，我们将研究旨在中断CLL与基质细胞相互作用的药物的疗效和机制。我们的目标是确定哪些CLL患者将从这些治疗中获益最多。

DESCRIPTION (provided by applicant): With the growing number of therapies being tested in chronic lymphocytic leukemia (CLL) comes the growing challenge of identifying for each patient which therapies are the best. In this competitive renewal proposal, we propose strategies to identify therapeutic opportunities in individual CLL tumors. A key element of this approach is the ability to predict patient response to individual therapies. We apply many of the basic lessons we have learned in the initial grant period about control of apoptosis, and make use of a tool that we refined in that proposal, BH3 profiling. Building on our prior work in which we found we can correlate in vitro sensitivity to ABT-737 to BH3 profiling results, we propose to test our ability to predict clinical response to the related BCL-2 antagonist, ABT-199 in CLL (Specific Aim #1). In addition, in Specific Aim #2, we propose to identify pathway addiction in individual cases of CLL. In the past, inefficiency of siRNA and shRNA approaches and difficulty of ex vivo culture in CLL have made this issue difficult to address by conventional means. We propose a study using small molecule pathway inhibitors instead of knockdown strategies to evade RNA transfection difficulties. Importantly, we use BH3 profiling to measure early apoptotic signaling within 4-24 of drug treatment, obviating the need for extended ex vivo culture. Our aim is to link early apoptotic signaling in response to small molecule inhibitors to pathway addiction. An important advantage of this approach is that detection of apoptotic signaling in primary CLL in response to drugs provides a rational path to clinical translation. Finally, in Specific Aim #3, we propose to investigate how stromal interactions inhibit apoptotic signaling in CLL cells. Moreover, using in vitro co-culture systems, we will study the efficacy and mechanisms of drugs intended to interrupt CLL interactions with stromal cells. Our goal is to identify which CLL patients will most benefit from such therapies.