Probing mitochondria and personalizing leukemia therapy with BH3 profiling

描述(由申请者提供)：随着慢性淋巴细胞白血病(CLL)试验的治疗方法越来越多，为每个患者确定哪些治疗方法是最好的面临着越来越大的挑战。在这个竞争性的更新方案中，我们提出了一些策略，以确定个别CLL肿瘤的治疗机会。这种方法的一个关键因素是预测患者对个别治疗的反应的能力。我们应用了我们在最初的拨款期间学到的许多关于控制细胞凋亡的基本经验教训，并利用了我们在该提案中改进的工具，BH3图谱。在我们之前的工作基础上，我们发现我们可以在体外将ABT-737的敏感性与BH3图谱结果相关联，我们建议测试我们预测CLL中相关bcl2拮抗剂ABT-199的临床反应的能力(特定目标#1)。此外，在特定的目标#2中，我们建议在慢性淋巴细胞白血病的个别病例中识别路径成瘾。过去，siRNA和shRNA方法的效率低下，以及CLL体外培养的困难，使得这一问题很难通过常规手段解决。我们提出了一项研究，使用小分子途径抑制剂而不是击倒策略来避免RNA转染困难。重要的是，我们使用BH3图谱来测量药物治疗后4-24天内的早期凋亡信号，从而消除了延长体外培养的需要。我们的目标是将早期的凋亡信号与小分子抑制剂的反应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CLL对药物的反应中的凋亡信号为临床翻译提供了一条合理的途径。最后，在第三个具体目标中，我们 建议研究基质相互作用如何抑制CLL细胞的凋亡信号。此外，利用体外共培养系统，我们将研究旨在阻断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患者将从这种治疗中受益最多。

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.