Targeting apoptotic caspases to enhance cancer radiotherapy

项目摘要 长期以来，人们认为放射治疗成功的基础是直接杀死和消除肿瘤细胞。 癌细胞因此，大多数先前的研究工作都集中在增强直接杀伤 放疗的效果。然而，最近，人们意识到，宿主免疫系统起着关键作用， 在确定细胞毒性癌症疗法的治疗结果中的作用。在许多情况下， 显示放射治疗可以激活免疫系统攻击癌细胞。但 对辐射诱导的免疫细胞活化所涉及的分子机制知之甚少。 在目前的项目中，我们打算测试这样一个假设，即阻断某些凋亡半胱天冬酶， 将通过增加放射治疗和免疫检查点抑制剂的功效来增强放射治疗和免疫检查点抑制剂的功效 免疫原性细胞死亡。我们的假设是基于两个已发表的数据对免疫刺激 我们的初步数据表明，阻断放射治疗的免疫原性效果很强， 凋亡半胱天冬酶。 为了验证我们的假设，我们将尝试通过使用小鼠的细胞模型来分析单个半胱天冬酶的作用。 用CRISPR-Cas9介导的基因敲除肿瘤细胞，并评估它们对CRISPR-Cas9的反应。 体外放射治疗和小鼠放射治疗（目的1）。然后我们将尝试识别半胱天冬酶的下游因子 其在辐射诱导的免疫原性细胞死亡（Aim 2）中是重要的。最后，我们将评估是否 抑制半胱天冬酶是一种可行的策略， 检查点抑制剂疗法（Aim 3）。 在完成我们提出的项目后，我们希望建立凋亡的生物学作用， caspase在放射治疗过程中免疫原性细胞死亡中的作用，为caspase的评价奠定了基础 抑制剂作为增强放射治疗和免疫检查点抑制剂治疗的潜在药物， 人类病人

PROJECT SUMMARY The basis for the success of radiation therapy is long believed to be direct killing and elimination of cancer cells. Therefore, most previous research efforts have focused on enhancing the direct killing effects of radiotherapy. However, recently, it was realized that the host immune system plays key roles in determining the treatment outcome of cytotoxic cancer therapy. In many instances, it has been shown that radiation therapy can activate the immune system to attack cancer cells. However, the molecular mechanisms involved in radiation-induced immune cell activation are poorly understood. In the current project, we intend to test the hypothesis that blockade of certain apoptotic caspases will enhance the efficacy of radiotherapy and immune checkpoint inhibitors by increasing immunogenic cell death. Our hypothesis is based on both published data on the immune-stimulatory effect of radiotherapy and our preliminary data demonstrating strong immunogenic effects of blocking apoptotic caspases. To test our hypothesis, we will attempt to dissect the roles of individual caspases by use of murine tumor cells with CRISPR-Cas9 mediated genetic knockout and evaluating their response to radiotherapy in vitro and in mice (Aim 1). We will then try to identify downstream factors of caspases that are important in radiation induced immunogenic cell death (Aim 2). Finally, we will evaluate if inhibition of caspases is a feasible strategy to enhance radiotherapy in combination with immune- checkpoint inhibitor therapy (Aim 3). Upon completion of our proposed project, we hope to establish the biological roles of apoptotic caspases in immunogenic cell death during radiotherapy and lay the foundation for evaluating caspase inhibitors as potential agents to enhance radiotherapy and immuno-checkpoint inhibitor therapy in human patients.