Targeting apoptotic caspases to enhance cancer radiotherapy

项目总结 长期以来，人们一直认为放射治疗成功的基础是直接杀死和消除 癌细胞。因此，以前的研究大多集中在增强直接杀伤力上 放射治疗的效果。然而，最近人们意识到，宿主免疫系统起着关键作用 在决定细胞毒性癌症治疗结果中的作用。在许多情况下，它一直是 研究表明，放射疗法可以激活免疫系统，攻击癌细胞。然而， 辐射诱导免疫细胞激活的分子机制目前知之甚少。 在目前的项目中，我们打算测试这样一种假设，即阻断某些凋亡的caspase 将通过增加放射治疗和免疫检查点抑制剂的疗效 免疫原性细胞死亡。我们的假设是基于两种已发表的关于免疫刺激的数据 放射治疗的效果和我们的初步数据表明封闭具有很强的免疫原性 凋亡的半胱氨酸酶。 为了验证我们的假设，我们将尝试用小鼠来剖析单个半胱氨酸酶的作用。 CRISPR-Cas9介导的基因敲除肿瘤细胞及其对 体外和小鼠放射治疗(目标1)。然后我们将尝试确定caspase的下游因子。 它们在辐射诱导的免疫原性细胞死亡中起重要作用(目标2)。最后，我们将评估是否 抑制半胱氨酸天冬氨酸氨基转移酶是一种可行的策略，以加强放射治疗与免疫- 检查点抑制疗法(目标3)。 在我们提议的项目完成后，我们希望建立细胞凋亡的生物学作用。 半胱氨酸天冬氨酸酶在放射治疗中免疫原性细胞死亡中的作用 作为潜在的药物来加强放射治疗和免疫检查点抑制治疗 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.