Metabolic adaptation enables cisplatin resistance and inhibits tumor immunity

项目1总结 更清楚地了解肿瘤细胞如何在铂制剂的压力下生存并进化为 耐药人群对于克服治疗失败和最大限度地控制疾病和 生死存亡。我们的数据表明，对顺铂具有获得性耐药的HNSCC细胞株减少了糖酵解和 线粒体产生能量，同时增加进入合成代谢途径的碳流量。这将导致一个 通过葡萄糖和谷氨酰胺分解代谢增强还原电位(谷胱甘肽、NAD(P)H、FADH2) 加上谷胱甘肽(GS)过氧化物酶2(GPX2)活性的增加，在基因组和 转录水平，部分通过Keap1-NRF2途径。伴随着GPX2的过度激活 可能抑制NF-κB的激活，减少肿瘤细胞主导的趋化因子和前列腺素的产生 一种富含髓系来源抑制细胞的抑制性肿瘤免疫微环境(TIME) (MDSCs)和去细胞毒肿瘤浸润性淋巴细胞(TIL)。这是我们的中心假设 代谢适应是获得顺铂耐药所允许的和必需的步骤。我们 进一步假设这种代谢转变会将一些肿瘤转变为免疫沉默的表型， 减少免疫监视以复合攻击性行为和交叉治疗抵抗力 顺铂治疗肿瘤 我们将首先定义产生增强还原状态所需的关键代谢步骤 支持AIM 1对顺铂的耐药性。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GS合成的贡献，并使用 化学抑制加上shRNA阻断单个转运体和酶，确定关键 HNSCC GS合成的限速代谢步骤与顺铂耐药性。在《目标2》中我们将 确定GS的合成和利用(通过GPX2和非GPX方法)是如何转录协调的 至少部分通过NRF2，以支持顺铂耐药。在目标3中，我们将测试GS的影响 通过典型的(例如，核因子-kB)代谢和代谢旁分泌信号在抑制性疾病的发生中的作用 时间到了。 拟议实验的完成将：1)确定合适的目标，用于消融 增强还原状态驱动HNSCC顺铂耐药2)确定代谢生物标志物 与基于13C通量成像的测量相结合，以生成肿瘤治疗的实时读数 反应，并提供更个性化的靶向代谢方法，以克服顺铂耐药性。 通过确定代谢适应的关键机制基础，我们可以产生一个范式 我们快速检测获得对基因毒性应激的抵抗力并克服它的能力的转变 使用多种临床可行的方法。它将进一步阐明顺铂是如何获得的 耐药性会影响对免疫调节方法的反应，如免疫检查点抑制剂 (ICIS)目前正与临床上的化疗相结合。

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.