Metabolic adaptation enables cisplatin resistance and inhibits tumor immunity

项目1 更清楚地了解肿瘤细胞如何在铂剂的压力下生存并演变成 耐药人群对于克服治疗失败和最大限度地控制疾病和 生存我们的数据表明，具有获得性顺铂抗性的HNSCC细胞系减少糖酵解和糖代谢。 线粒体能量产生，同时增加碳通量进入合成代谢途径。这导致 通过葡萄糖和谷氨酰胺催化剂增强还原电位（谷胱甘肽、NAD（P）H、FADH 2） 再加上增加的谷胱甘肽（GS）过氧化物酶2（GPX 2）活性协调在基因组和 转录水平，部分通过KEAP 1-NRF 2途径。GPX 2的过度活化伴随 可能抑制NF-κB活化，减少肿瘤细胞产生的趋化因子和前列腺素， 一种富含髓源性抑制细胞的抑制性肿瘤免疫微环境（TIME） 细胞毒性肿瘤浸润性淋巴细胞（TIL）被耗尽。我们的核心假设是， 代谢适应是获得顺铂抗性的允许和必需步骤。我们 进一步假设这种代谢转变使一些肿瘤转变为免疫沉默表型， 这降低了免疫监视，从而加剧了攻击性行为和交叉治疗抗性， CDDP治疗的肿瘤 我们将首先定义生成增强还原态所需的关键代谢步骤 支持Aim 1中顺铂耐药的基因。我们将利用体外和体内原位HNSCC模型， 测量葡萄糖和谷氨酰胺对顺铂耐药肿瘤中GS合成的贡献， 化学抑制结合shRNA阻断单个转运蛋白和酶，确定关键的 HNSCC中GS合成和顺铂抗性的限速代谢步骤。在目标2中， 确定GS合成和利用（通过GPX 2和非GPX手段）如何在转录上协调 至少部分地通过Nrf 2以支持顺铂抗性。在目标3中，我们将测试GS的影响 通过典型的（例如NF-kB）和代谢旁分泌信号传导的代谢对抑制性肿瘤的发展起作用。 时间 完成拟议的实验将：1）确定合适的目标消融的 增强的还原状态驱动HNSCC中的顺铂抗性，和2）鉴定代谢生物标志物，其可以 耦合到基于13 C通量成像的测量，以生成肿瘤治疗的实时读数 反应，并告知一个更个性化的方法来靶向代谢，以克服CDDP耐药性。 通过识别代谢适应的关键机制基础，我们可以生成一个范例， 我们快速检测对遗传毒性应激获得抗性和克服它的能力的转变 使用多种临床可行的方法。它将进一步阐明如何收购顺铂 耐药性可影响对免疫调节方法的反应，如免疫检查点抑制剂 目前在临床上，ICIs与化疗相结合。

Project 1 SUMMARY A clearer understanding of how tumor cells survive the stress of platinum agents and evolve into therapy resistant populations is essential to overcome treatment failure and maximize both disease control and survival. Our data demonstrate that HNSCC cell lines with acquired cisplatin resistance reduce glycolytic and mitochondrial energy production while increasing carbon flux into anabolic pathways. This results in an enhanced reductive potential (glutathione, NAD(P)H, FADH2) via both glucose and glutamine catabolism coupled to increased glutathione (GS) peroxidase 2 (GPX2) activity coordinated at a genomic and transcriptional level, partially through the KEAP1-NRF2 pathway. Hyperactivation of GPX2 concomitantly likely inhibits NF-κB activation, decreasing chemokine and prostaglandin production by tumor cells— leading to a suppressive tumor immune microenvironment (TIME) enriched for myeloid derived suppressor cells (MDSCs) and depleted of cytotoxic tumor infiltrating lymphocytes (TILs). It is our central hypothesis that this metabolic adaptation is a permissive and required step for acquisition of cisplatin resistance. We further postulate that this metabolic shift transitions some tumors to an immunologically silent phenotype, which reduces immune surveillance to compound the aggressive behavior and cross-therapy resistance of CDDP-treated tumors We will first define the critical metabolic steps required for generation of an enhanced reductive state that supports cisplatin resistance in Aim 1. We will utilize in vitro and in vivo orthotopic HNSCC models to measure the contribution of glucose and glutamine to GS synthesis in cisplatin resistant tumors and, using chemical inhibition coupled to shRNA blockade of individual transporters and enzymes, identify the critical rate limiting metabolic steps for GS synthesis and cisplatin resistance in HNSCC. In Aim 2 we will determine how GS synthesis and utilization (by GPX2 and non GPX means) are coordinated transcriptionally at least in part through Nrf2 in order to support cisplatin resistance. In Aim 3 we will test the impact of GS metabolism via canonical (e.g. NF-kB) and metabolic paracrine signaling on development of a suppressive TIME. Completion of the proposed experiments will: 1) identify suitable targets for ablation of the enhanced reductive state driving cisplatin resistance in HNSCC and 2) identify metabolic biomarkers which can be coupled to 13C flux imaging-based measurements to generate real-time readout of tumor treatment response, and inform a more personalized approach to targeting metabolism to overcome CDDP resistance. By identifying the critical mechanistic underpinnings of metabolic adaptation, we can generate a paradigm shift in our capability to both rapidly detect acquisition of resistance to genotoxic stress and to overcome it using multiple clinically viable approaches. It will further shed light on how acquisition of cisplatin resistance can impact response to immunomodulatory approaches such as immune checkpoint inhibitors (ICIs) currently being combined with chemotherapy in the clinic.