The 3D whole Body Distribution of NIR transferrin using FRET tomography imaging

说明(申请人提供)：转铁蛋白是一种众所周知的铁结合蛋白，负责通过与转铁蛋白受体的结合将铁带入细胞。此外，由于转铁蛋白受体在肿瘤中表达上调，转铁蛋白已被广泛用作抗癌药物输送系统的载体。靶向递送是开发癌症有效治疗方法的一种重要和有前途的方法。我们的主要目标是使用3D全身断层成像来可视化受体介导的转铁蛋白细胞摄取。为了实现这一目标，我们建议利用转铁蛋白受体的同源二聚体性质，并使用荧光共振能量转移(FRET)在体内成像组织吸收近红外(NIR)铁结合转铁蛋白的能力。我们将使用全身多光谱时间分辨荧光分子断层成像(FMT)成像平台来测量体内和3D中受体的二聚化。总之，我们将在体内检测和成像受体介导的近红外转铁蛋白细胞摄取，以定量检测基于转铁蛋白的靶向递送系统，用于诊断和治疗用途。这一建议超越了目前的标准方法，结合了最先进的临床前光学成像方法来定量评估膜结合受体的二聚化，例如。转铁蛋白受体，通过监测FRET。FRET FMT成像以一种非侵入性但在体内的方式工作，使定量数据易于获得，以前所未有的特异性和灵敏度定位和测量受体介导的转铁蛋白细胞摄取量。这项研究计划的长期目标是开发一种新的临床模式，以确定在个体癌症中由受体二聚体激活的受体通路。这种非侵入性技术是缺乏的，但将通过允许设计一种个性化的治疗方案来深刻影响患者的管理，该方案仅由那些将靶向和阻断在特定肿瘤中激活的受体通路的药物组成，以进行积极和成功的治疗。 公共卫生相关性：转铁蛋白(TFN)是一种众所周知的铁结合蛋白，负责通过与TFN受体(TFR)的结合将铁带入细胞。重要的是，TFR已被证明在肿瘤中高表达，并促进乳腺肿瘤的生长。由于肿瘤中TFR的上调，TFN已被广泛用作抗癌药物/siRNA递送系统的载体。靶向递送是开发癌症有效治疗方法的一种重要和有前途的方法。我们的主要目标是开发一种非侵入性全身成像系统，能够区分非特异性受体非依赖性肿瘤蓄积和受体介导的肿瘤细胞摄取，从而能够直接可视化TFN靶向粒子进入肿瘤细胞的过程。为了实现这一目标，该建议超越了目前的标准方法，通过结合荧光分子断层成像(FMT)成像和荧光共振能量转移(FRET)探针，通过在体内监测近红外(NIR)供体-TFN和NIR-受体-TFN与TFR同源二聚体结合的FRET，定量评估受体介导的肿瘤对NIR-TFN的摄取。因此，我们将在体内成像受体介导的NIR-TFN细胞摄取图像，用于定量检测基于TFN的靶向递送系统，用于诊断和治疗。

DESCRIPTION (provided by applicant): Transferrin is a well known iron-binding protein, which is responsible for carrying iron into the cells via its binding to the transferrin receptor. Moreover, transferrin has been widely used as carrier for anti-cancer drug delivery systems since the transferrin-receptor is upregulated in tumors. Targeted delivery is an important and promising approach for the development of effective therapy in cancer applications. Our main goal is to use 3D whole body tomographic imaging to visualize the receptor-mediated transferrin cellular uptake. Towards this goal, we propose to capitalize on the homodimeric nature of the transferrin receptor and employ Fluorescence Resonance Energy Transfer (FRET) to image in vivo the ability of tissues to take up near-infrared (NIR) iron-bound transferrin. We will use a whole body multispectral time-resolved fluorescence molecular tomography (FMT) imaging platform to measure receptor dimerization in vivo and in 3D. In summary, we will detect and image in vivo receptor-mediated NIR-transferrin cell uptake for the quantitative detection of the transferrin-based targeted delivery systems for diagnostic and therapeutic use. This proposal leapfrogs over current standard approaches to incorporate the most advanced pre-clinical optical imaging approach to assess quantitatively the dimerization of membrane-bound receptors, e,.g. transferrin receptor, by monitoring FRET. FRET FMT imaging works in a non-invasive but in vivo manner, making quantitative data readily available to localize and measure the amount of receptor-mediated transferrin cellular uptake with unprecedented specificity and sensitivity. The long term goal of this research program is to develop a new clinical modality to identify receptor pathways that are activated by receptor dimerization in an individual's cancer. Such non-invasive technique is lacking but will profoundly impact patient management by allowing to devise an individualized therapeutic regimen consisting only of those drugs that will target and block the receptor pathways that are activated in that particular tumor for aggressive and successful therapy. PUBLIC HEALTH RELEVANCE: Transferrin (Tfn) is a well known iron-binding protein, which is responsible for carrying iron into the cells via its binding to the Tfn-receptor (TFR). Importantly, TFR has been shown to be highly expressed in tumors and to promote the growth of breast tumors. Due to the upregulation of TFR in tumors, Tfn has been widely used as carrier for anti-cancer drug/siRNA delivery systems. Targeted delivery is an important and promising approach for the development of effective therapy in cancer applications. Our main goal is to develop a non-invasive whole-body imaging system that can discriminate non-specific receptor-independent tumor accumulation from receptor-mediated uptake into the tumor cells, thus allowing the direct visualization of the delivery of Tfn-targeted particles into tumor cells. Towards this goal, this proposal leapfrogs over current standard approaches by combining fluorescence molecular tomographic (FMT) imaging and Fluorescence Resonance Energy Transfer (FRET) probes to assess quantitatively the receptor-mediated tumor uptake of NIR-Tfn by monitoring in vivo FRET between near-infrared (NIR)-donor-Tfn and NIR-acceptor- Tfn bound to TFR homodimers. Hence, we will image in vivo receptor-mediated NIR-Tfn cell uptake for the quantitative detection of the Tfn-based targeted delivery systems for diagnostic and therapeutic use.