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 项目概要/摘要 播散性转移性黑色素瘤最初用V600 E突变的BRAF激酶抑制剂治疗， 它是控制黑色素瘤细胞复制的MAPK信号通路的组成部分。一半以上 黑色素瘤患者表达这种突变，并且至少最初对其抑制有反应。然而，所有的PA- 患者最终会对这些抑制剂产生耐药性，必须采用替代疗法进行治疗，这包括： 主要是免疫检查点抑制剂。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 这些代理人。我们实现这一目标的策略是研究BRAF ki的详细生化机制， nase信号转导的前提是肿瘤代谢的变化是一个更快和更可靠的指标， 耐药性的发生比肿瘤体积的变化更重要，这可能需要数周至数月才能可靠地 manifest.我们将利用13 C MRS和液相色谱质谱（LC-MS）来研究其作用机制。 BRAF代谢抑制，但这些方法不适用于人体内检测-13C MRS不够灵敏，LC-MS是侵入性的。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代谢反应 转移（CEST），其比1H MRS灵敏约500倍，但需要高磁场强度。 在≥ 7 T下运行的部件。而1H MRS可在1.5T或3 T条件下进行监测，这两种条件下的仪器都是有用的。 能够在更多的医疗机构。我们的第二个目标是描述BRAF的生物标志物是如何在 为了更好地理解他们的能力和局限性，最后，我们自己的初步数据 实验室和其他人的研究表明，对突变型BRAF抑制剂的耐药性的发生涉及到一个突变型BRAF抑制剂的转变。 肿瘤从依赖有氧糖酵解到实质上更依赖于ox-phos和谷氨酰胺- nolysis。这导致了使用ox-phos抑制剂（如二甲双胍和非那普利）的临床试验， 延迟抵抗的开始作为我们的第三个目标，我们建议测试使用CB-839的可行性， 谷氨酰胺酶抑制剂阻断谷氨酰胺依赖性转变作为抑制BRAF发作的方法 阻力我们的具体目标是：目标1将确定MAPK的生化变化和有效性 在小鼠和人黑素瘤模型中的途径抑制。目标2将阐明生物- 化学效应和生物标志物对微环境变化的响应。目标3将验证拟议的 在一个实施方案中，本发明涉及在体内系统中的生物标志物，其中使用谷氨酰胺酶抑制剂改变治疗反应。 临床影响：该项目将通过NMR方法检测黑色素瘤对靶向治疗的反应， 已经在临床上在传统的1.5T和3 T仪器上以及在7 T仪器上实施的ODS- 越来越常见的工具。代谢组学研究将扩大我们的能力， 在细胞中、小鼠和人类模型中，以及最终在人类中，使肿瘤代谢发生变化。

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.