Sensitizing Colorectal Cancer to Checkpoint Inhibitors by WNT Pathway Suppression

项目摘要 每年有超过180万人被诊断患有结直肠癌（CRC）， 虽然内镜筛查导致死亡率略有下降，但该疾病仍占 全世界每年有80万人死亡。然而，在过去的10-15年里，CRC的治疗方法几乎没有变化。 免疫检查点抑制剂（ICI）最近已成为治疗以下疾病的令人兴奋的治疗选择： 高度突变的转移性CRC（占所有CRC的15%）和各种其他肿瘤类型。然而，对于剩下的 对于大多数结直肠癌患者，目前还没有有效的靶向治疗。临床研究表明 WNT通路激活和T细胞排斥之间的联系，这可以解释为什么ICIs不能产生抗肿瘤作用。 CRC中的免疫反应。WNT信号通路的过度激活是一个标志性的主要致癌因素， CRC的驱动因素，约95%的肿瘤发生。我们实验室对小鼠的早期研究支持WNT 信号传导促进免疫抑制并调节免疫细胞募集， 可以阻断已形成肿瘤的免疫抑制。在实验室中使用精密模型，我将测试 WNT信号传导驱动CRC中的免疫抑制和抑制CRC中的WNT信号传导的假设 会激活肿瘤对ICIs的免疫反应为了解决这个问题，我将使用一个模型系统， 使用肿瘤类器官移植的转移性CRC-临床上使用ICI的疾病背景。三 将产生具有三种不同水平的WNT激活的类器官系，所有这些都可以被调节以 完全抑制WNT通路。在目标1中，我将确定不同水平的WNT的效果 结肠肿瘤内效应免疫群体的信号传导。此外，我的目标是测试WNT信号是否 在已建立的WNT活性结肠肿瘤内的抑制促进抗肿瘤免疫的募集 种群并逆转免疫抑制。我所采用的遗传方法允许诱导和 WNT信号转导调节的可逆控制。这个系统是唯一强大的解决我的假设， 它允许评估肿瘤细胞内有效的WNT激活和抑制。在目标2中，我旨在确定 如果WNT信号传导抑制刺激对ICI的免疫应答，导致肿瘤消退。我会先 评估具有肿瘤内在WNT抑制的肿瘤中的免疫应答。然后我将评估药理学 WNT通路抑制，非特异性靶向，但具有临床相关性，能够概括 基因发现确定一种安全有效的方法来刺激抗肿瘤免疫力将产生深远的影响 对CRC临床管理的影响。因此，我们相信我们的工作将有助于重要的临床前数据 开发用于激活CRC和潜在其他肿瘤类型的免疫疗法的联合疗法 激活WNT信号

PROJECT SUMMARY More than 1.8 million people are diagnosed with colorectal cancer (CRC) each year, and while increased rates of endoscopic screening have led to a slight reduction in mortality, the disease still accounts for more than 800,000 deaths worldwide annually. Treatments for CRC have changed little over the past 10-15 years, though immune checkpoint inhibitors (ICIs) have recently become an exciting therapeutic option for the treatment of hypermutated metastatic CRC (15% of all CRCs) and various other tumor types. However, for the remaining majority of CRC patients, there exist no effective targeted therapies. Clinical studies have revealed a correlation between WNT pathway activation and T-cell exclusion, that may explain why ICIs do not generate anti-tumor immune responses in CRC. Hyperactivation of the WNT signaling pathway is a hallmark and major oncogenic driver of CRC, occurring in ~95% of tumors. Early work from our lab in mice supports the notion that WNT signaling promotes immune suppression and regulates immune cell recruitment and that WNT pathway inhibition can block immune suppression in established tumors. Using precision models in the lab, I will test the hypothesis that WNT signaling drives immune suppression in CRC and inhibiting WNT signaling in CRC will activate tumor immune responses to ICIs. To address this question, I will utilize a model system of metastatic CRC using tumor organoid transplants—the disease setting in which ICIs are used in the clinic. Three organoid lines will be generated to have three distinct levels of WNT activation, all of which can regulated to undergo complete WNT pathway suppression. In Aim 1, I will determine the effect of distinct levels of WNT signaling on effector immune populations within colon tumors. Further, I aim to test whether WNT signaling suppression within established, WNT-active colon tumors facilitates recruitment of anti-tumor immune populations and reverses immune suppression. The genetic approach I am employing allows for inducible and reversible control of WNT-signaling modulation. This system is uniquely powerful to address my hypothesis as it allows an assessment of potent WNT activation and suppression within tumor cells. In Aim 2, I aim to determine if WNT signaling suppression stimulates immune response to ICIs resulting in tumor regression. I will first evaluate immune responses in tumors with tumor intrinsic WNT suppression. I will then assess pharmacological WNT pathway inhibition, that targets non-specifically but is clinically relevant, in its ability to recapitulate the genetic findings. Identifying a safe and effective approach to stimulate anti-tumor immunity will have a profound impact on the clinical management of CRC. Thus, we believe our work will contribute significant pre-clinical data to develop combination therapies for the activation of immunotherapies in CRC and potentially other tumor types with activated WNT signaling.