Project 2: Defining Targetable Metabolic Dependencies in Human Renal Cell Carcinoma

项目摘要 癌症中的代谢重编程是一个有吸引力的治疗靶点来源，因为它促进肿瘤生长 和通过原则上易于用小分子抑制的酶转移。代谢 重编程是肾细胞癌（RCC）固有的。事实上，很少有肿瘤与代谢 在一些实施方案中，所述细胞是肾细胞癌，特别是透明细胞肾细胞癌（ccRCC）。这表现为：透明细胞表型， 其由脂质/糖原积累引起;由ccRCC签名事件引起的直接代谢重编程， VHL失活;以及观察到代谢酶的生殖系突变导致RCC，但很少有其他突变。 肿瘤类型靶向代谢重编程的两个主要障碍是缺乏关于RCC的知识 这可能与患者的代谢有关，并且缺乏经验证的翻译平台。为了应对这些挑战，我们 在第1 - 5年执行了5项主要活动。首先，我们开创了术中输注13 C标记的营养素， 患者直接报告人类RCC代谢，其中包括葡萄糖抑制 氧化其次，我们从机制上表明，葡萄糖氧化抑制是由于缺乏氧化应激。 磷酸化第三，我们确定无添加剂的原位植入患者肿瘤（肿瘤移植物， TG）是研究人肾细胞癌代谢的有效模型。第四，我们建立了体内代谢实验室， 一个创新的翻译平台，用于检测人类肿瘤中的代谢重编程， 研究人员正在寻找新的治疗策略，在TG模型和原发性人类肿瘤组织中测试它们，并推进最有前途的线索。 第五，我们证明了原发性ccRCC肿瘤和转移瘤都使用谷氨酰胺来维持氧化还原， 平衡并产生必需的生物合成中间体。基于我们和其他人的发现， 在癌症中，开发了CB-839谷氨酰胺酶抑制剂。然而，ccRCC试验的结果表明， 令人失望一种可能的解释是，转氨酶只是分解代谢的几种酶之一， 谷氨酰胺。我们的新数据不仅解释了CB-839缺乏疗效，而且还发现了新的机会， 干预事实上，虽然CB-839通过靶向谷氨酰胺酶来抑制碳代谢，但谷氨酰胺也是一种抗氧化剂。 RCC中的氮源，通过酰胺基转移酶进行加工，不受CB-839的抑制。在 初步数据，我们表明，泛谷氨酰胺抑制与JHU-083不仅有效地抑制， 这不仅可以抑制酰胺转移酶反应，而且还显著阻断ccRCC TG生长。为了提高有效的谷氨酰胺 针对临床，在6 - 10年，我们将追求以下目标。目标1.探索的作用 酰胺转移酶介导对CB-839转氨酶抑制剂的抗性。目标二。将IDH酶靶向至 最大化谷氨酰胺阻断。目标3：为了最大限度地发挥谷氨酰胺靶向作用， 使用下一代模型的微环境

Project Summary Metabolic reprogramming in cancer is an attractive source of therapeutic targets because it fuels tumor growth and metastasis through enzymes that are in principle amenable to inhibition with small molecules. Metabolic reprogramming is intrinsic to renal cell carcinoma (RCC). In fact, few tumors are as profoundly linked to metabolic derangement as RCC and in particular, clear cell RCC (ccRCC). This is shown by: the clear cell phenotype, which arises from lipid/glycogen accumulation; direct metabolic reprogramming by the ccRCC signature event, VHL inactivation; and the observation that germline mutations in metabolic enzymes cause RCC, but few other tumor types. The two main barriers to targeting metabolic reprograming are the lack of knowledge about RCC metabolism in patients and the absence of validated translational platforms. To address these challenges, we executed 5 major activities in Years 1 – 5. First, we pioneered intraoperative infusions of 13C-labeled nutrients in patients to directly report on RCC metabolism in humans, which revealed, among others, suppressed glucose oxidation. Second, we showed, mechanistically, that suppressed glucose oxidation is due to deficient oxidative phosphorylation. Third, we determined that additive-free, orthotopically implanted, patient tumors (tumorgrafts, TG) are valid models to study human RCC metabolism. Fourth, we established the In Vivo Metabolism Lab, an innovative translational platform to detect metabolic reprogramming in human tumors, nominate therapeutic strategies, test them in TG models and primary human tumor tissue, and advance the most promising leads. Fifth, we demonstrated that both primary ccRCC tumors and metastases use glutamine to maintain redox balance and produce essential biosynthetic intermediates. Building upon discoveries by us and others implicating glutamine in cancer, the CB-839 glutaminase inhibitor was developed. However, results in ccRCC trials have been disappointing. One possible explanation is that glutaminase is only one of several enzymes that catabolize glutamine. Our new data not only explain CB-839 lack of efficacy, but also identify new opportunities for intervention. Indeed, while CB-839 inhibits carbon metabolism by targeting glutaminase, glutamine is also a source of nitrogen in RCC, which is processed via amidotransferases, which are not inhibited by CB-839. In preliminary data, we show that pan-glutamine inhibition with JHU-083 not only effectively inhibits amidotransferase reactions, but also significantly blocks ccRCC TG growth. To advance effective glutamine targeting to the clinic, in Years 6 – 10, we will pursue the following Aims. Aim 1. Probing the role of amidotransferases in mediating resistance to CB-839 glutaminase inhibitor. Aim 2. Targeting IDH enzymes to maximize glutamine blockade. Aim 3. To maximize the impact of glutamine targeting by leveraging the tumor microenvironment using next-generation models.