Targeting KRAS and adenosine mediated immunosuppression in pancreatic cancer

项目摘要 激活KRAS突变，改变代谢和免疫抑制肿瘤微环境都是 胰腺导管腺癌（PDAC）的标志。KRASG 12 C的突破性发现 特异性抑制剂重新燃起了直接靶向这一主导驱动致癌基因的希望， “无法抗拒”然而，越来越清楚的是，突变KRAS的治疗潜力 PDAC和其他恶性肿瘤中的抑制剂只有在作为 合理设计的联合疗法。识别可采取行动的免疫调节和代谢事件 在PDAC中，通过KRASG 12 C抑制触发转录组学、蛋白质组学和代谢组学分析， 在人和鼠模型中进行。胰腺癌细胞中的KRASG 12 C抑制限制了表达 免疫抑制趋化因子，增加抗原呈递途径，减少营养（葡萄糖和 谷氨酰胺）消耗和免疫抑制代谢物（乳酸盐）的产生。这些研究 表明KRASG 12 C抑制剂在PDAC中发挥免疫引发作用，并支持与 免疫检查点阻断剂（ICB）。然而，这些免疫启动效应伴随着 核苷酸代谢的改变和细胞外腺苷水平的升高。这一发现具有重大意义。 潜在的意义，因为已知腺苷通过结合腺苷A2 a/A2 b来减少抗肿瘤免疫 受体（A2 aR/A2 bR）在广泛的免疫细胞类型。尚待确定，如果 在KRASG 12 C PDAC中，为了治疗目的而利用的观察结果是：（i） KRASG 12 C抑制调节PDAC细胞中的核苷酸代谢和腺苷水平，（ii）必需的 当在动物中共靶向KRASG 12 C和A2 aR/A2 bR时，ICB的组分（抗PD-1和/或抗CTLA-4） 模型，以及（iii）靶向腺苷信号传导是否促进KRASG 12 C抑制和 KRASG 12 C PDAC患者的ICB。目标1中提议的研究将检验以下假设： 由KRASG 12 C抑制诱导的腺苷水平反映了核苷酸代谢的改变，这导致了 增加胰腺肿瘤细胞腺苷流出和减少腺苷摄取。目标2要求 共靶向KRASG 12 C、A2 aR/A2 bR和常规免疫的组合的基于机械的测试 在新的KRASG 12 C胰腺癌的原位、转移和遗传小鼠模型中的检查点。目标3 包括首次在人体中进行的代谢物启动的IA/IB期临床试验，以测试 我们的联合疗法作为胰腺癌患者的二线治疗。拟议的研究将建立一个 KRASG 12 C抑制，核苷酸代谢， 腺苷信号传导和免疫抑制。他们还将 为正向和反向翻译研究提供基础，以改善免疫治疗反应， KRASG 12 C PDAC患者，以及其他KRASG 12 C恶性肿瘤患者。

PROJECT SUMMARY Activating KRAS mutations, altered metabolism, and an immunosuppressive tumor microenvironment are all hallmarks of pancreatic ductal adenocarcinoma (PDAC). The recent groundbreaking discovery of KRASG12C specific inhibitors has reinvigorated hope for direct targeting of this dominant driver oncogene formerly deemed “undruggable”. However, it is becoming increasingly clear that the therapeutic potential of mutant KRAS inhibitors in PDAC and other malignancies will only be realized if they are administered as components of rationally designed combination therapies. To identify actionable immunomodulatory and metabolic events triggered by KRASG12C inhibition in PDAC, transcriptomic, proteomic, and metabolomic analyses were performed in human and murine models. KRASG12C inhibition in pancreatic cancer cells limited the expression of immunosuppressive chemokines, increased antigen presentation pathways, reduced nutrient (glucose and glutamine) consumption, and the production of immunosuppressive metabolites (lactate). These studies indicate that KRASG12C inhibitors exert immune-priming effects in PDAC and support combinations with immune checkpoint blockade (ICB) agents. However, these immune-priming effects were accompanied by alterations in nucleotide metabolism and by elevated extracellular adenosine levels. This finding has great potential significance since adenosine is known to curtail anti-tumor immunity by engaging adenosine A2a/A2b receptors (A2aR/A2bR) on a broad array of immune cell types. Remaining to be determined, if these observations are to be exploited for therapeutic purposes in KRASG12C PDAC, are (i) the mechanisms by which KRASG12C inhibition modulates nucleotide metabolism and adenosine levels in PDAC cells, (ii) the requisite components of ICB (anti-PD-1 and/or anti-CTLA-4) when co-targeting KRASG12C and A2aR/A2bR in animal models, and (iii) whether targeting adenosine signaling promotes synergy between KRASG12C inhibition and ICB in patients with KRASG12C PDAC. Studies proposed in Aim 1 will test the hypothesis that elevations in adenosine levels induced by KRASG12C inhibition reflect alterations in nucleotide metabolism, leading both to increased pancreatic tumor cell adenosine efflux and to decreased adenosine uptake. Aim 2 entails mechanistically-based testing of combinations co-targeting KRASG12C, A2aR/A2bR and conventional immune checkpoints in new orthotopic, metastatic and genetic murine models of KRASG12C pancreatic cancer. Aim 3 consists of a first-in-human investigator-initiated phase IA/IB clinical trial to test the tolerability and efficacy of our combinations as second-line therapies in patients with pancreatic cancer. Proposed studies will establish a new mechanistic framework of interrelationships between KRASG12C inhibition, nucleotide metabolism, adenosine signaling, and immunosuppression both in mouse models of PDAC and in patients. They will also provide the foundation for forward and reverse translation studies to improve immunotherapy responses in patients with KRASG12C PDAC and, potentially, in other KRASG12C malignancies.