Dynamic BH3 Profiling with Patient Derived Organoids of Esophageal Cancer and Mesothelioma Enable Precision-Based Targeting of the Mitochondrial Apoptotic Pathway

总结/摘要 食管癌和恶性胸膜间皮瘤是很难治疗的，因为它们通常隐藏在 3000个体细胞突变来自反流和石棉的反复伤害。确定一个突变或途径， 肿瘤细胞通过新的突变和旁路途径绕过靶标。基于这个原因， 靶向线粒体途径代表了一种实质性改进的方法，因为它们 致癌驱动蛋白和途径突变的下游。 最近，我们已经表明，慢性暴露前肿瘤，巴雷特食管细胞的胆盐诱导 通过称为“少数MOMP（线粒体外膜）”的机制恶性转化 透化作用MOMP受B细胞淋巴瘤-2（Bcl-2）蛋白家族调节，该蛋白家族分为 在Bcl-2同源性-3（BH 3）结构域相互作用的促凋亡蛋白和抗凋亡蛋白。少数MOMP部分 激活凋亡机制的内在途径至不足以导致细胞死亡的水平;相反， 促进基因组不稳定性、细胞转化和肿瘤发生。我们注意到，在“少数派MOMP”中， Barrett细胞通过上调抗凋亡蛋白Mcl-1抵抗凋亡。当我们瞄准 Mcl-1、少数MOMP从亚致死性线粒体激活转变为坦率的凋亡和肿瘤细胞 死了动态BH 3谱（DBP）提供了一种测定哪种抗凋亡蛋白负责 每个肿瘤的抗药性通过确定相关的抗凋亡蛋白，一类化合物，BH 3 模拟物，靶向那些特定的蛋白质。最近，一种生物化学“工具包”利用DBP来识别适当的 过表达bcl-2蛋白的鼠细胞中的BH 3模拟物。患者源性类器官（PDO）可以 概括肿瘤对治疗的反应。如果在PDO中使用DBP的综合生化工具包 直接从患者肿瘤中识别出能够产生耐药性的蛋白质，然后基于精确的靶向 Bcl-2蛋白提供了克服难治性癌症的治疗策略。 我们的目标是破坏线粒体平衡，使致癌，但阻止细胞凋亡，直接通过 靶向负责抗性的蛋白质。我们将建立一个生化工具包来预测治疗 食管癌和间皮瘤的反应，通过利用DBP-PDO模型。针对这些蛋白质将 通过阻断代偿性抗凋亡蛋白使少数MOMP向凋亡方向转变。我们的假设是 DBP-PDO模型在肿瘤活检后7天内是临床上可行的生物测定。该电流 研究将使我们能够通过以下方式完全绕过棘手的旁路机制和癌细胞的突变， 靶向下游线粒体抗性机制。这一新战略预计将改变少数民族 MOMP对坦率的凋亡，从而使这些细胞容易受到标准疗法。

SUMMARY / ABSTRACT Esophageal cancer and malignant pleural mesothelioma are difficult to treat because they typically harbor over 3000 somatic mutations from the repeated insults of reflux and asbestos. Identifying one mutation or pathway to target is circumvented by the tumor cell through new mutations and bypass pathways. For this reason, targeting the mitochondrial pathways represents a substantially improved approach because they are downstream of oncogenic driver proteins and pathway mutations. Recently, we have shown that chronic exposure of pre-neoplastic, Barrett’s esophageal cells to bile salt induced malignant transformation through a mechanism termed, ‘Minority MOMP (mitochondrial outer membrane permeabilization)’. MOMP is regulated by the B-cell lymphoma-2 (Bcl-2) family of proteins that are divided into pro- and anti-apoptotic proteins that interact at Bcl-2 homology-3 (BH3) domains. Minority MOMP partially activates the intrinsic pathway of the apoptotic machinery to a level not sufficient to result in cell death; rather, it promotes genomic instability, cellular transformation, and tumorigenesis. We noted that in ‘Minority MOMP’, Barrett’s cells resisted apoptosis through the upregulation of the anti-apoptotic protein, Mcl-1. When we targeted Mcl-1, Minority MOMP shifted from the sub-lethal mitochondrial activation to frank apoptosis and tumor cells died. Dynamic BH3 profiling (DBP) provides an assay to measure which anti-apoptotic proteins are responsible for the resistance for each tumor. By determining the relevant anti-apoptotic protein, a class of compounds, BH3 mimetics, target those specific protein. Recently, a biochemical ‘toolkit’ utilized DBP to identify the appropriate BH3 mimetic in murine cells that overexpressed bcl-2 proteins. Patient-derived organoids (PDO) can recapitulate tumor response to therapy. If a comprehensive biochemical toolkit utilizing DBP in PDOs identifies proteins that enable resistance directly from patient tumors, then precision-based targeting of the Bcl-2 proteins provides a therapeutic strategy to overcome treatment-refractory cancers. Our goal is to disrupt the mitochondrial balance that enables carcinogenesis but blocks apoptosis by directly targeting the proteins responsible for resistance. We will establish a biochemical toolkit to predict treatment response in esophageal cancer and mesothelioma by utilizing a DBP-PDO model. Targeting these proteins will shift Minority MOMP toward apoptosis by blocking the compensatory anti-apoptotic proteins. Our hypothesis is that the DBP-PDO model is a clinically actionable bioassay within seven days from tumor biopsy. This current research will allow us to circumvent intractable bypass mechanisms and mutations of cancer cells altogether by targeting the downstream mitochondrial resistance mechanism. This novel strategy is expected to shift Minority MOMP toward frank apoptosis and thus render these cells vulnerable to standard therapies.