Combining senescence-inducing and senolytic agents to improve melanoma therapy

项目摘要 转移性黑色素瘤是侵袭性肿瘤，对化疗和放疗反应不佳， 迅速获得对靶向治疗的耐药性。虽然免疫检查点抑制剂（ICI）可以诱导 在持续的黑色素瘤缓解中，近一半的患者对ICI具有内在抗性，部分原因是他们的 肿瘤太大而不能被免疫系统清除，或者在免疫学上是“冷的”并且缺乏免疫系统。 这是产生抗肿瘤T效应细胞所必需的识别。我们的初步数据显示衰老- 诱导治疗增强转录因子NF-κ B驱动的黑色素瘤细胞内在促炎程序 κB。我们鉴定了RIG-I样受体（RLR）途径作为候选NF-κB诱导剂。这种促炎剂 该计划涉及增强抗原呈递和趋化因子的分泌， 细胞进入肿瘤。我们还发现衰老细胞过度表达检查点分子PD-L1和半乳糖凝集素， 9，其可以通过分别结合其抑制性受体PD-1和TIM-3来抑制T细胞。这表明 衰老诱导疗法可以增强对肿瘤抗原的识别，同时靶向衰老- 特定的免疫检查点可以促进针对这些抗原的过继性T细胞反应。 尽管其免疫原性，衰老诱导剂的治疗应用是复杂的 据报道，持续的衰老细胞可能促进肿瘤转移、复发和化疗耐药性。 在这里，我们假设，我们可以安全地提高黑色素瘤免疫原性诱导肿瘤细胞， 在有限的时间内衰老，然后使用衰老药物消除持续衰老的细胞， 专门杀死衰老细胞。这种新的治疗方法预计是有效的：1）直接 阻断肿瘤细胞生长和存活，2）激活TLR介导的肿瘤细胞内在免疫刺激性， 信号，以及3）使肿瘤细胞对PD-L1/PD 1和半乳糖凝集素9/TIM 3免疫抑制剂敏感 检查站三个具体目标将审查这些机制。在第一个目标中，我们将建立最佳的 用于组合的衰老诱导和衰老清除疗法的给药方案，并确定直接的抗肿瘤作用。 在免疫缺陷小鼠模型中的功效。使用我们广泛表征的黑色素瘤进行的临床前试验 将进行PDX以估计对衰老诱导和衰老清除药物组合的应答率 并鉴定反应预测生物标志物。第二个目标是研究 衰老诱导和衰老清除疗法促进肿瘤的先天免疫感应， 的RLR。我们将研究RLR信号传导的缺陷是否可以消除NF-κB活化，趋化因子 分泌和免疫细胞募集到衰老肿瘤中。目标三将确定是否衰老诱导 和衰老清除疗法增强免疫检查点抑制剂（ICI）应答。我们将使用抗PD-L1抗体， 抗TIM 3剂靶向衰老细胞特异性免疫检查点。这些研究将提供一个 为临床开发衰老诱导剂和衰老清除剂的合理组合提供了临床前基础。

Project Summary Metastatic melanomas are aggressive tumors that respond poorly to chemotherapy and radiation and promptly acquire resistance to targeted therapy. While immune checkpoint inhibitors (ICIs) can induce sustained melanoma remission, nearly half of patients are intrinsically resistant to ICIs, in part because their tumors are too large to be cleared by the immune system or are immunologically “cold” and lack immune recognition necessary to generate anti-tumor T effector cells. Our preliminary data show that senescence- inducing therapy enhances melanoma-cell intrinsic pro-inflammatory program driven by transcription factor NF- κB. We identified the RIG-I-Like Receptor (RLR) pathway as a candidate NF-κB inducer. This pro-inflammatory program involves enhanced antigen presentation and secretion of chemokines that recruit antigen-presenting cells into the tumor. We also found that senescent cells overexpress checkpoint molecules PD-L1 and Galectin 9, which can inhibit T cells by binding their inhibitory receptors PD-1 and TIM-3, respectively. This suggests that senescence-inducing therapy can enhance recognition of tumor antigens while targeting senescence- specific immune checkpoints can promote adoptive T cell responses against these antigens. Despite its immunogenic properties, therapeutic application of senescence-inducing agents is complicated by the reports that persistent senescent cells may promote tumor metastasis, relapse, and chemo-resistance. Here we hypothesize that we can safely improve melanoma immunogenicity by inducing tumor cell senescence for a limited time, followed by elimination of persistent senescent cells using senolytic drugs that specifically kill senescent cells. This novel therapeutic approach is expected to be effective by: 1) directly blocking tumor cell growth and survival, 2) activating RLR-mediated tumor cell intrinsic immuno-stimulatory signals, and 3) making tumor cells vulnerable to inhibitors of PD-L1/PD1 and Galectin 9/TIM3 immune checkpoints. Three specific aims will examine these mechanisms. In the first aim we will establish the optimal dosing schedule for combined senescence-inducing and senolytic therapy and determine the direct anti-tumor efficacy in an immune-deficient mouse model. A pre-clinical trial using our extensively characterized melanoma PDXs will be conducted to estimate response rate to senescence-inducing and senolytic drug combinations and to identify response-predictive biomarkers. Second aim will investigate the mechanisms whereby senescence-inducing and senolytic therapy facilitates the innate immune sensing of tumor focusing on the role of RLRs. We will examine whether deficiency in RLR signaling can abrogate NF-κB activation, chemokine secretion, and immune cell recruitment into senescent tumors. Aim three will determine if senescence-inducing and senolytic therapy augments immune checkpoint inhibitor (ICI) responses. We will utilize anti-PD-L1 and anti-TIM3 agents to target senescence-cell specific immune checkpoints. These studies will provide a preclinical basis for clinical development of rational combinations of senescence-inducing and senolytic agents.