Optical platform for functional longitudinal imaging of metabolite uptake in vivo

项目总结 癌细胞进行新陈代谢重新编程，以满足更高的能量需求以提供燃料 因此，与正常细胞相比，它们对许多必需代谢物的利用存在差异。 癌症代谢再编程领域的最新进展显示， 当与癌症代谢抑制剂联合使用时，标准癌症治疗的有效性。然而，肿瘤 对于大多数癌症来说，代谢重编程仍然知之甚少。而且，最近的许多报道， 发现的证据表明，癌细胞在体外的代谢与体内的代谢可以有很大的不同，因为 体外模型缺乏肿瘤微环境的复杂性。然而，肿瘤的研究进展 由于缺乏能够进行实时非侵入性成像的有效工具，体内的新陈代谢严重受阻 以及在癌症动物模型中对代谢物吸收的量化，这与人类的病理密切相关。 目前的策略有很大的局限性，主要依赖于磁共振成像、核成像技术，如 PET/SPECT和体外代谢产物吸收终点定量(例如Ms)。在这里，我们建议开发 一种新型光学成像平台，与现有方法相比具有几个重要的优点，并允许 用高灵敏度和可定量的方法对几种主要代谢物的摄取进行无创评估 生物发光成像。该方法不受放射性和/或短寿命同位素的影响，成本较低， 允许在疾病进展期间(例如，癌症发展或 临床干预，如化疗)。虽然这种方法的第一次应用已经 我们以葡萄糖为例成功地验证了(Maric等人，NAT方法，2019)，我们建议 扩展这项技术以开发新的探针来研究几种氨基酸、脂肪酸和 核苷都在癌症代谢重新编程中起着核心作用。我们将进行彻底的验证 该平台在细胞、健康转基因小鼠和小鼠癌症动物模型中确保试剂满足 在体外和体外对生理行为、稳定性、安全性和强健信号产生的要求 活着。此外，我们还将优化体内给药路线、车辆和浓度，以实现高 信号/背景比。总之，本研究的总体目标是生成一种新型的光学成像平台 这将成为监测活细胞和动物模型中营养摄取的通用分析工具 疾病。虽然我们计划应用这个平台来解开肿瘤代谢重新编程，但同样的方法可以 适用于其他几种重要的人类病理研究，在这些研究中，代谢的变化是已知的 发挥重要作用，如糖尿病、神经退行性疾病、非酒精性脂肪性肝炎(NASH)、 还有其他许多人。因此，这项新技术有望产生强大的、使能的和持久的影响 关于新陈代谢领域的许多生理和病理研究，并将成为一个有价值的工具 用于药物发现，适用于肿瘤学和其他代谢紊乱。

PROJECT SUMMARY Cancer cells undergo metabolic reprogramming in order to meet elevated energy requirements to fuel proliferation, thus resulting in their differential utilization of many essential metabolites compared to normal cells. Recent advancements in the field of cancer metabolic reprogramming demonstrated significant increase in efficiency of standard cancer treatments when combined with cancer metabolic inhibitors. However, tumor metabolic reprogramming remains poorly understood for the majority of cancers. Moreover, many recent reports revealed evidence that the metabolism of cancer cells in vitro can differ significantly from that of in vivo because in vitro models lack complexity of the tumor microenvironment. However, the progress of studying tumor metabolism in vivo is significantly hampered by the lack of efficient tools that allow real-time noninvasive imaging and quantification of metabolite absorption in animal models of cancer which closely reflect human pathologies. Current strategies have significant limitations and mostly rely on MRI, nuclear imaging techniques such as PET/SPECT, and endpoint ex vivo quantification of metabolite absorption (ex. MS). Here, we propose to develop a novel optical imaging platform that has several important advantages over the existing methods, and allows noninvasive evaluation of the uptake of several essential metabolites using highly sensitive and quantifiable bioluminescent imaging. The method is independent of radioactive and/or short-lived isotopes, less costly, and allows longitudinal monitoring of metabolite absorption during disease progression (e.g., cancer development or clinical intervention such as chemotherapy). While the first application of this approach has been already successfully validated by us using glucose as an example (Maric et.al., Nat Methods, 2019), we propose to expand this technology to develop novel probes to study uptake of several amino acids, fatty acids, and nucleosides that all play central role in cancer metabolic reprogramming. We will perform thorough validation of this platform in cells, healthy transgenic mice and murine animal cancer models to assure that the reagents fulfill the requirements for physiological behavior, stability, safety, and robust signal generation both in vitro and in vivo. In addition, we will optimize in vivo delivery routes, vehicles, and concentrations to achieve high signal/background ratios. In summary, the overall goal of this study is to generate a novel optical imaging platform that would become a universal analytical tool for monitoring nutrient uptake in live cells and animal models of disease. While we plan to apply this platform to unravel tumor metabolic reprogramming, the same method could be adapted for studies of several other important human pathologies, in which changes in metabolism are known to play a significant role, such as diabetes, neurodegenerative diseases, nonalcoholic steatohepatitis (NASH), and many others. Therefore, this novel technology is expected to have a strong, enabling, and long-lasting impact on many physiological and pathological investigations in the field of metabolism and will become a valuable tool for drug discovery, applicable to oncology and other metabolic disorders.