Development of pH-Sensitive Probes for in vivo Cerenkov Imaging

用于体内切伦科夫成像的 pH 敏感探针的开发

• 批准号: 10543250
• 负责人: Andrea Estefania Guzman
• 金额: $ 1.38万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10543250
• 关键词: 90Y; Acidity; Attenuated; Beta Particle; Binding; Biodistribution; Breast Cancer Model; Breast Cancer cell line; Buffers; Cell Line; Cells; Chelating Agents; Chemicals; Chemoresistance; Cherenkov Radiation; Development; Electrodes; Electrons; Elementary Particles; Energy Transfer; Environment; Enzymes; Evaluation; Exhibits; Extracellular Space; Fluorescence; Glycolysis; Goals; High Pressure Liquid Chromatography; Image; Imaging Techniques; In Vitro; Intravenous; Link; MDA MB 231; Mass Spectrum Analysis; Measurement; Measures; Metabolic; Metabolism; Metastatic breast cancer; Methods; Modeling; Modification; Mus; NMR Spectroscopy; Needles; Neoplasm Metastasis; Nucleotides; Nude Mice; Optics; Pharmacology; Photons; Physiological; Play; Positron; Positron-Emission Tomography; Production; Property; Protons; Pyruvate; Radioisotopes; Radiolabeled; Resistance; Role; Signal Transduction; Solid Neoplasm; Speed; Structure; Techniques; Testing; Time; Titrations; Toxic effect; Travel; Variant; absorption; attenuation; cancer cell; chelation; cherenkov imaging; chromophore; extracellular; fluorophore; imaging platform; in vivo; in vivo evaluation; in vivo imaging; inhibitor; interest; lightspeed; malignant breast neoplasm; metabolic profile; metal chelator; novel; optical imaging; optical spectra; particle; pre-clinical; response; tool; tumor; tumor microenvironment; uptake

PROJECT SUMMARY/ABSTRACT The principal goal of this project is to develop pH-sensitive fluorophores to determine tumor microenvironment pH in breast cancer models using Cerenkov imaging. Increased acidity in the tumor microenvironment (TME) plays a role in the invasion and metastasis of cancer cells and contributes to chemotherapeutic resistance. This metabolic hallmark has sparked interest in the exploration of extracellular tumor pH measurement and imaging in vivo. The decrease in tumor microenvironment pH is due to a deregulated metabolism predominantly arising from increased glycolytic flux in cancer cells. Cerenkov radiation emitted by β-particles is a potential tool for pH imaging in vivo, since pH-sensitive fluorophores or chromophores can selectively attenuate its multispectral emission, providing a quantitative readout. Cerenkov radiation occurs when subatomic particles like electrons and positrons emitted from decaying nucleotides travel faster than the speed of light in a dielectric medium. The high speed at which these subatomic particles travel results in the production of multispectral photons along the particle’s trajectory. This multispectral emission is continuous, includes the visible spectrum and can be selectively attenuated by pH sensitive fluorophores or chromophores at the absorption maxima of the compounds. The selective signal attenuation, known as selective bandwidth quenching can be quantified and correlated with a pH value, providing a non-invasive technique for pH imaging in vivo. This proposal will test the hypothesis that selective absorption of the Cerenkov multispectral emission by pH sensitive fluorophores will provide accurate pH measurements of the TME through Cerenkov imaging. The hypothesis will be tested by the following Specific Aims: Specific Aim 1: Synthesis and characterization of Cerenkov-active, pH sensitive fluorophores: This will include conjugation and chelation of selected pH-sensitive fluorophores with the metal chelators DOTA or NOTA and radiometals 68Ga and 90Y, in addition to chemical and optical characterization. Specific Aim 2: In vitro evaluation of Cerenkov-active, pH sensitive fluorophores: A pH titration curve will be constructed to correlate average radiance values obtained through Cerenkov imaging to pH values. Cell uptake and toxicity studies will be performed. Specific Aim 3: In vivo evaluation of Cerenkov-active, pH sensitive fluorophores: Synthesized probes will be injected intravenously into mice bearing breast cancer tumors. PET imaging will be used to assess biodistribution and probe delivery into tumors. Cerenkov imaging will be used to measure TME pH. Pharmacological modulation of lactate transport using syrosingopine will be done to alter the tumor pH and assess sensitivity of the Cerenkov imaging technique.

项目摘要/摘要 本计画的主要目标是发展pH敏感的萤光团以侦测肿瘤微环境 使用Cerenkov成像的乳腺癌模型中的pH。肿瘤微环境（TME）酸度增加 在癌细胞的侵袭和转移中起作用，并导致化疗抗性。 这种代谢标志已经引发了对细胞外肿瘤pH测量的探索的兴趣， 体内成像。肿瘤微环境pH值的降低是由于代谢失调 主要由癌细胞中糖酵解通量增加引起。β粒子发射的切伦科夫辐射是 一个潜在的工具，在体内pH成像，因为pH敏感的荧光团或生色团可以选择性地 衰减其多光谱发射，提供定量读数。 切伦科夫辐射发生时，亚原子粒子，如电子和正电子发射衰变 核苷酸在电介质中的传播速度比光速快。这些高速运动 亚原子粒子的移动导致沿着粒子的轨迹沿着产生多光谱光子。这 多光谱发射是连续的，包括可见光谱，并且可以通过pH选择性地衰减 敏感的荧光团或发色团在化合物的吸收最大值。选择性信号 衰减，称为选择性带宽淬灭，可以量化并与pH值相关， 提供了一种用于体内pH成像的非侵入性技术。 该提议将检验以下假设： 灵敏的荧光团将通过切伦科夫成像提供TME的精确pH测量。的 假设将通过以下具体目标进行检验： 具体目标1：切伦科夫活性、pH敏感荧光团的合成和表征：这将包括 所选pH敏感荧光团与金属螯合剂DOTA或NOTA的缀合和螯合， 放射性金属68 Ga和90 Y，除了化学和光学特性。 具体目标2：Cerenkov活性、pH敏感荧光团的体外评价：pH滴定曲线将为 构造成将通过切伦科夫成像获得的平均辐射值与pH值相关联。细胞 将进行摄取和毒性研究。 具体目标3：切伦科夫活性、pH敏感荧光团的体内评估：将合成探针 静脉注射到携带乳腺癌肿瘤的小鼠中。PET成像将用于评估 生物分布和探针递送到肿瘤中。Cerenkov成像将用于测量TME pH值。 将使用西罗辛戈平进行乳酸转运的药理学调节以改变肿瘤pH， 评估切伦科夫成像技术的灵敏度。