Combining senescence-inducing and senolytic agents to improve melanoma therapy

项目摘要 转移性黑色素瘤是一种对化疗和放疗反应不佳的侵袭性肿瘤。 迅速获得对靶向治疗的抵抗力。而免疫检查点抑制剂(ICIS)可以诱导 持续的黑色素瘤缓解，近一半的患者对ICIS具有内在抵抗力，部分原因是他们的 肿瘤太大，无法被免疫系统清除，或者在免疫上“冷”，缺乏免疫力。 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- 诱导治疗增强黑色素瘤细胞的内在促炎程序，由转录因子NF-2驱动 κB。我们发现RIG-I样受体(RLR)通路是一种候选的NF-κB诱导剂。这是一种促炎 该计划包括增强抗原提呈和趋化因子的分泌，以招募抗原提呈 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Galectin 9，可通过分别与T细胞的抑制受体PD-1和TIM-3结合来抑制T细胞。这表明 诱导衰老治疗可以在靶向衰老的同时增强对肿瘤抗原的识别- 特定的免疫检查点可以促进针对这些抗原的过继T细胞反应。 尽管具有免疫原性，但衰老诱导剂的治疗应用是复杂的。 据报道，持续衰老的细胞可能促进肿瘤的转移、复发和化疗耐药。 在这里，我们假设我们可以通过诱导肿瘤细胞来安全地提高黑色素瘤的免疫原性 在有限的时间内衰老，然后使用抗衰老药物消除持续衰老的细胞 专门杀死衰老的细胞。这种新的治疗方法有望通过以下方式有效：1)直接 阻断肿瘤细胞的生长和存活；2)激活RLR介导的肿瘤细胞内源性免疫刺激 信号，以及3)使肿瘤细胞易受PD-L1/PD1和Galectin 9/TIM3免疫抑制剂的影响 检查站。三个具体目标将检验这些机制。在第一个目标中，我们将建立最优 诱导衰老和抗衰老联合给药方案及直接抗肿瘤作用的确定 在免疫缺陷小鼠模型中的疗效。利用我们广泛表征的黑色素瘤进行的临床前试验 将进行PDXS以评估对诱导衰老和抗衰老药物组合的应答率 并确定可预测反应的生物标志物。第二个目标将调查 促衰老和抗衰老治疗促进肿瘤先天免疫感知的作用 关于RLR的。我们将研究RLR信号的缺陷是否可以取消NF-κB的激活，趋化因子 分泌和免疫细胞募集进入衰老的肿瘤。目标三将确定是否会导致衰老 而感觉化治疗增强了免疫检查点抑制物(ICI)的反应。我们将利用抗PD-L1和 抗TIM3药物靶向衰老细胞特异性免疫检查点。这些研究将提供一个 抗衰老和抗衰老药物合理组合的临床前基础。

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.