Small Molecule Activators of Pro-apoptotic BAX for Cancer Therapy

描述（由申请人提供）：靶向关键凋亡调节剂以克服癌细胞的凋亡抗性是一种非常有吸引力的治疗策略。促凋亡基因BAX 是BCL-2蛋白家族的关键成员，BCL-2蛋白家族由相反的促凋亡和抗凋亡成员组成，其在线粒体凋亡途径中决定细胞的生命和死亡。促凋亡BAX在活化后从细胞质易位到线粒体以执行线粒体外膜的透化，线粒体凋亡的“不归点”。BAX在细胞死亡调节、肿瘤发生和化疗诱导的癌细胞死亡中的作用已得到充分证实。此外，抗凋亡BCL-2成员（BAX的抑制剂）的显著过表达在癌细胞中很常见，并有助于肿瘤发生和化学抗性。因此，绝大多数癌细胞含有功能性但受抑制的BAX。我们以前发现了调节胞质BAX激活的BAX触发位点和结合BAX触发位点并诱导BAX激活的小分子，从而能够直接和合理地靶向这种高姿态的凋亡靶点。在这里，我们建议评估BAX的触发位点作为重新激活癌细胞死亡的新药理学策略的潜力，并在耐药急性髓系白血病（AML）的背景下研究BAX激活剂分子（BAM）作为有前途的原型治疗剂。具体而言，我们将1）在结合、结构和生物化学研究中表征新型BAM，以选择性地结合BAX触发位点并诱导BAX活化，2）研究BAX的直接活化机制以重新活化人AML细胞和遗传修饰的癌细胞中的BAX介导的凋亡，3）检查直接BAX活化的治疗功效，在人AML异种移植物和体外和体内毒性研究中，使用我们的新型先导化合物，以及4）合成新型BAM用于靶向验证和改进效力、选择性和药理学性质。因此，我们提出了一种多学科的方法，结合合成化学，结构生物学，生物化学，癌细胞生物学和体内疗效研究，以验证一种新的小分子治疗方法，以恢复癌细胞死亡，并提供BAM作为癌症治疗的潜在领导结构。

DESCRIPTION (provided by applicant): Targeting key apoptosis regulators to overcome the apoptotic resistance of cancer cells is a highly attractive therapeutic strategy. Pro-apoptotic BAX is a critical member of the BCL-2 protein family, which is composed of opposing pro- and anti-apoptotic members that dictate cellular life and death at the mitochondrial apoptotic pathway. Pro-apoptotic BAX, upon activation, translocates from the cytosol to the mitochondria to execute permeabilization of the outer mitochondrial membrane, the "point of no return" for mitochondrial apoptosis. The role of BAX in cell death regulation, tumorigenesis and chemotherapy-induced cancer cell death has been well established. Furthermore, significant overexpression of anti-apoptotic BCL-2 members, the inhibitors of BAX, is common in cancer cells and contributes to tumorigenesis and chemoresistance. Therefore, the vast majority of cancer cells contain functional but suppressed BAX. We previously discovered the BAX trigger site that regulates the activation of cytosolic BAX and a small molecule that binds to the trigger site of BAX and induces BAX activation, enabling the direct and rational targeting of this high-profile apoptotic target. Here, we propose to evaluate the potential of the trigger site of BAX as a novel pharmacological strategy to reactivate cancer cell death and investigate BAX activator molecules (BAMs) as promising prototype therapeutics, in the context of resistant Acute Myeloid Leukemia (AML). Specifically, we will 1) characterize novel BAMs in binding, structural and biochemical studies for binding selectively to the BAX trigger site and induction of BAX activation, 2) investigate the direct activation mechanism of BAX to reactivate BAX-mediated apoptosis in human AML cells and genetically modified cancer cells, 3) examine the therapeutic efficacy of direct BAX activation, in human AML xenografts and in vitro and in vivo toxicity studies, using our novel lead compound and 4) synthesize novel BAMs for target validation and improvement of potency, selectivity and pharmacological properties. Thus, we propose a multidisciplinary approach that combines synthetic chemistry, structural biology, biochemistry, cancer cell biology and in vivo efficacy studies to validate a novel small-molecule therapeutic approach to restore cancer cell death and provide BAMs as potential lead structures for cancer therapeutics.