Imaging of Pharmacotherapy Induced Apoptosis

描述（由申请人提供）：能够在促细胞凋亡/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价，并允许临床中已建立的治疗的个性化。这种成像方法的分子基础在于这样的事实，即当细胞沿着沿着途径进行凋亡或死亡时，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是用于成像药物疗法的有吸引力的靶点，因为（i）不同的药物疗法具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物，以及（iii）PS可以使用膜联蛋白V成像，膜联蛋白V是选择性结合PS的蛋白质，并且已用作放射性标记的临床诊断剂。使用荧光膜联蛋白V，我们已经获得了重要的原理数据证据，即荧光膜联蛋白V（38 kDa）的积累反映了在多种疾病（癌症、关节炎）的动物模型中对抗增殖药物治疗的早期反应。我们还表明，磁/光膜联蛋白V（50 nm）可用于成像缺血诱导的细胞凋亡的MRI在体内。尽管Tc-膜联蛋白V已用于成像化疗反应，但迄今为止的临床结果可以被描述为有限和混合的。该建议的前提是，膜联蛋白V为基础的探针可以成功地用于成像化疗诱导的细胞凋亡，提供了一个大大提高的理解膜联蛋白V如何结合到肿瘤和内皮细胞强调各种化疗药物在体外获得。此外，必须了解关于膜联蛋白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和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。该建议将提供关于膜联蛋白V探针与经受化疗应激的细胞的相互作用的重要信息，并允许成像细胞凋亡以实现其尚未被认识到的巨大潜力。它将为基于在接受治疗的肿瘤上上调的分子标记物的表达来选择药物治疗方案提供基础，表明哪些方案对特定个体有效，并且避免许多不提供益处的副作用倾向方案。

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.