Melanoma: Metabolic Biomarkers of Response to Targeted Therapy

黑色素瘤：靶向治疗反应的代谢生物标志物 项目摘要/摘要 播散性转移性黑色素瘤最初使用V600E突变的BRAF激酶的抑制剂治疗，a MAPK信号通路的组成部分，控制黑色素瘤细胞的复制。超过一半的 黑色素瘤患者表达这种突变，至少最初对它的抑制有反应。然而，所有的人- 患者最终会对这些抑制剂产生抗药性，并不得不采用替代疗法进行治疗，这种疗法包括 主要由免疫检查点抑制剂组成。该项目的目标是开发一种成像方法， 可以监测BRAF激酶抑制剂的有效性，并可以及时准确地检测对 这些特工。为了实现这一目标，我们的战略是研究BRAF Ki-的详细生化机制。 Nase信号转导的前提是肿瘤新陈代谢的变化是更快、更可靠的指标 比起肿瘤体积的改变，耐药性的出现可能需要几周到几个月的时间才能变得可靠 明示。我们将使用~(13)C-MRS和液-质联用(LC-MS)对其进行研究。 BRAF代谢抑制的NISM，但这些方法不适合在体内检测人类-13C MRS不够灵敏，LC-MS具有侵入性。因此，我们的策略是确定合适的生物标志物 可通过1H MRS或MRI监测的化学交换饱和度监测的代谢反应 转移(CEST)，其灵敏度约为1H MRS的500倍，但需要较高的磁场装置。 以≥7T运行的终端。相比之下，1H MRS可在1.5T或3T下进行监测，可使用以下仪器- 能够在更多的医疗机构工作。我们的第二个目标是描绘BRAF的生物标记物是如何- 为了更好地了解他们的能力和局限性，他们将努力工作。最后，来自我们自己的初步数据 Lab和其他人的研究表明，对突变的BRAF抑制剂的抗药性的开始涉及到 肿瘤从依赖有氧糖酵解到更多地依赖OX-磷酸和谷氨酰胺- 溶血。这导致了临床试验使用OX-磷酸酶抑制剂，如二甲双胍和苯福明，以 延缓抗药性的发生。作为我们的第三个目标，我们建议测试使用CB-839的可行性，这是一种在- 阻断谷氨酰胺依赖的谷氨酰胺酶抑制剂作为抑制BRAF发病的一种方法 抵抗。我们的具体目标是：目标1将决定MAPK的生化变化和有效性 黑色素瘤小鼠和人类模型中的通路抑制。AIM 2将阐明底物对生物的限制 微环境变化的化学效应和生物标志物响应。目标3将验证提议的 体内系统中的生物标记物，其中治疗反应使用谷氨酰胺酶抑制剂来修改。 临床影响：该项目将能够通过核磁共振方法检测黑色素瘤对靶向治疗的反应。 已经在临床上在1.5T和3T常规仪器上以及在7T仪器上实施的消耗臭氧层物质。 乐器正变得越来越普遍。代谢组学研究将扩展我们研究全-的能力 研究肿瘤在细胞中的代谢，在小鼠和人类模型中，最终在人类中。

Melanoma: Metabolic Biomarkers of Response to Targeted Therapy Project Summary/Abstract Disseminated metastatic melanoma is initially treated with inhibitors of the V600E mutated BRAF kinase, a component of the MAPK signaling pathway that controls the replication of melanoma cells. More than half of melanoma patients express this mutation and are at least initially responsive to its inhibition. However, all pa- tients eventually become resistant to these inhibitors and have to be treated with alternate therapy, which con- sists primarily of immune checkpoint inhibitors. The goal of this project is to develop an imaging method that could monitor the effectiveness of BRAF kinase inhibitors and can promptly and accurately detect resistance to these agents. Our strategy for achieving this goal is to study the detailed biochemical mechanism of BRAF ki- nase signaling on the premise that a change in tumor metabolism is a quicker and more reliable indicator of the onset of resistance than a change in tumor volume, which can require weeks to months to become reliably manifest. We will use 13C MRS and liquid chromatography mass-spectrometry (LC-MS) to study the mecha- nism of BRAF metabolic inhibition, but these methods are not suitable for in vivo detection in humans – 13C MRS is not sensitive enough and LC-MS is invasive. Therefore, our strategy is to identify suitable biomarkers of metabolic response that can be monitored by 1H MRS or MRI monitored chemical exchange saturation transfer (CEST), which is about 500 times more sensitive than 1H MRS but requires high magnetic field instru- ments operating at ≥ 7T. In contrast, 1H MRS can be monitored at 1.5T or 3T, for which instruments are avail- able at many more medical institutions. Our second objective is to delineate how the biomarkers of BRAF inhi- bition work in order to better appreciate their capabilities and limitations. Finally, preliminary data from our own lab and from others indicates that the onset of resistance to mutant BRAF inhibitors involves a transition of the tumor from dependence on aerobic glycolysis to substantially greater dependence on ox-phos and on glutami- nolysis. This has led to clinical trials of the use of inhibitors of ox-phos such as metformin and phenformin to delay the onset of resistance. As our third objective, we propose to test the feasibility of using CB-839, an in- hibitor of glutaminase to block the transition to glutamine-dependence as a method to inhibit the onset of BRAF resistance. Our Specific Aims are: Aim 1 will determine biochemical changes and effectiveness of MAPK pathway inhibition in murine and human models of melanoma. Aim 2 will elucidate substrate limitations on bio- chemical effects and biomarker response to changes in microenvironment. Aim 3 will validate the proposed biomarkers in an in vivo system where the treatment response is modified using a glutaminase inhibitor. Clinical Impact: This project will enable detection of melanoma response to targeted therapy by NMR meth- ods that have already been implemented in the clinic on conventional 1.5T and 3T instruments and on 7T in- struments that are becoming progressively more common. Metabolomic studies will expand our ability to quan- tify tumor metabolism in cells, in mouse and human models, and eventually in humans.