Imaging of Pharmacotherapy Induced Apoptosis

描述（由申请人提供）：一种能够在促凋亡/抗增殖药物治疗过程中早期测量细胞凋亡增加的成像方法的开发将加速实验性临床前治疗的评估，并允许在临床中对已建立的治疗进行个性化。这种成像方法的分子基础在于，当细胞沿着凋亡或死亡的途径前进时，磷脂酰丝氨酸（PS），一种通常面向细胞质的脂质，翻转并面向细胞外环境。PS是成像药物治疗的一个有吸引力的目标，因为(i)不同的药物治疗都有诱导细胞凋亡的共同倾向，（ii） PS是细胞凋亡的早期和一般标记，（iii） PS可以使用膜联蛋白V成像，膜联蛋白V是一种选择性结合PS的蛋白质，已被用作放射性标记的临床诊断剂。利用荧光膜联蛋白V，我们获得了重要的原理数据证明，荧光膜联蛋白V （38kDa）的积累反映了多种疾病（癌症、关节炎）动物模型对抗增性药物治疗的早期反应。我们还证明了磁/光学膜联蛋白V （50 nm）可以通过MRI在体内成像缺血诱导的细胞凋亡。虽然tc -膜联蛋白V已被用于成像化疗反应，但迄今为止的临床结果是有限的和混合的。该提议的前提是，基于膜联蛋白V的探针可以成功地用于化疗诱导的细胞凋亡成像，从而大大提高了对膜联蛋白V如何在体外与各种化疗药物应激的肿瘤和内皮细胞结合的理解。此外，必须了解膜联蛋白V探针在体内行为的关键变量，包括阐明这些探针的细胞靶点，确定化疗诱导的肿瘤血容量变化是否使分子标记物PS的定量复杂化。这一提议将提供有关膜联蛋白V探针与化疗应激细胞相互作用的重要信息。并使成像细胞凋亡发挥其尚未被认识到的巨大潜力。它将为选择药物治疗方案提供基础，该方案基于在接受治疗的肿瘤上上调的分子标记的表达，表明哪种方案对特定个体有效，并保留许多副作用倾向的方案，这些方案没有任何益处。

DESCRIPTION (provided by applicant): The development of an imaging method capable of measuring the increase in apoptosis early in the course of pro-apoptotic/anti-proliferative pharmacotherapies will accelerate the evaluation of experimental pre- clinical therapies and permit the personalization of established therapies in the clinic. The molecular basis for such an imaging method lies in the fact that as cells proceed along pathways to apoptosis or death, phosphatidylserine (PS), a lipid normally facing the cytoplasm, flips and faces the extracellular milieu. PS is an attractive target for imaging pharmacotherapy because (i) diverse pharmacotherapies have a common propensity to induce apoptosis, (ii) PS is an early and general marker of apoptosis and, (iii) PS can be imaged using annexin V, a protein that binds PS selectively and which has been used as a radiolabeled clinical diagnostic agent. Using fluorescent annexin V's, we have obtained important proof of principle data that the accumulation of fluorescent annexin V (38kDa) reflects the early response to anti-proliferative drug treatment in animal models of diverse diseases (cancer, arthritis). We have also shown that a magneto/optical annexin V (50 nm) can be used to image ischemia induced apoptosis by MRI in vivo. Though Tc-annexin V has been used for imaging chemotherapeutic response, clinical results to date are can be described as limited and mixed. The premise of this proposal is that annexin V based probes can be successfully used to image chemotherapy induced apoptosis, provided a vastly improved understanding of how annexin V binds to tumor and endothelial cells stressed by various chemotherapic agents in vitro is obtained. In addition, key variables regarding annexin V probe behavior in vivo must be understood, including elucidation of the cellular targets of these probes and determination of whether chemotherapy induced changes in tumor blood volume complicate the quantitation of the molecular marker, PS. This proposal will provide essential information regarding the interaction of annexin V probes with cells subjected to chemotherapeutic stress, and allow imaging apoptosis to realize its as yet unrecognized and vast potential. It will provide a basis for the selection pharmotherapeutic regimes based on the expression of a molecular marker upregulated on tumors undergoing treatment, indicating which regimes will be efficacious for specific individuals, and sparing many side-effect prone regimes which provide no benefit.