VPAC1 Recpetor-Targeted PET Imaging of Prostate Cancer

描述(申请人提供)：前列腺癌的VPAC1受体靶向PET成像摘要前列腺癌(PC)影响每六个60岁的男性中就有一个，2011年将导致超过32,000名美国男性死亡。血清前列腺特异性抗原(PSA)测定、经直肠超声(TRUS)和磁共振成像(MRI)仍然是诊断和治疗PC的标准工具。这些方法中的每一种都需要侵入性活检以进行PC的组织学确认。活组织检查与发病率和高昂的费用有关。在美国每年进行的150万例活检中，超过65%的活检显示为良性病变，这表明这些标准诊断工具的假阳性率很高。这些局限性表明，迫切需要非侵入性方法来a)准确地定位高危原发PC，b)检测复发疾病和c)提高可靠性的图像转移性病变。为了解决这些问题，我们建议对PC进行早期、特异、非侵入性的放射成像。我们将针对VPAC1受体，它在肿瘤形成开始时在PC细胞上过度表达。我们已经成功地将VPAC1特异性铜多肽应用于前列腺癌移植瘤的成像。我们在模拟自发性人PC的TRAMP转基因小鼠上的结果表明，我们的铜--肽特异性并有效地靶向VPAC1。我们还在模拟自发性人乳腺癌(BC)的MMTV-neu转基因小鼠中证实了铜-多肽对VPAC1的特异性，包括VPAC1的过表达。我们已经使用铜--VPAC1肽启动了人体BC的正电子发射计算机断层扫描成像，取得了非常有希望的早期结果。因此，我们假设，使用VPAC1受体特异性铜-多肽进行正电子发射计算机断层扫描将加快PC的诊断，并有助于其管理，包括减少不必要的活检程序，减少治疗中或治疗过度产生的最小益处、大小便失禁或阳萎。我们将在四个具体目标上验证我们的假设：i)通过在裸鼠体内成像人PC异种移植来评估两个针对VPAC1的铜-多肽。Ii)通过与F-18FDG扫描、PC组织学、VPAC1RT-PCR和免疫组织化学的比较，确定最佳的铜多肽在模拟人PC发病机制的TRAMP转基因小鼠中的有效性，并验证VPAC1在TRAMP小鼠中对PC恶性的显像。3)进行毒理学检查，获得EIND；4)对25例PC术前患者进行可行性研究，选用最合适的铜多肽。PET成像结果应与组织学结果和整个PC腺体标测结果进行统计学评价。这项针对VPAC1的PC分子PET成像的翻译研究将产生一种经PC检测和成像特异性验证的PET成像肽。我们的战略合作伙伴Nuview提供了一支在放射性药物开发、临床试验和营销战略方面拥有专业知识的多学科工业团队，以确保这项技术从工作台到床边的成功转化。 公共卫生相关性：每六名60岁以上的男性中就有一人会患有前列腺癌(PC)，但准确可靠地诊断前列腺癌仍然是一项重大挑战，导致患者治疗不足或过度治疗，带来微乎其微的好处、巨大的发病率、大小便失禁和/或阳萎，同时花费数亿美元进行侵入性活检，以确认前列腺癌。我们将评估两个有希望的小分子，它们将被注射到可疑PC患者体内，然后它们将附着在PC细胞表面显示的特定癌变上，产生来自体外收集的附着分子的信号，以提供恶性PC的高精度和特异性图像。我们使用这些小分子的初步成像结果非常有希望消除目前的缺陷，并允许我们来自托马斯·杰斐逊大学和Nuview，Inc.的团队的专业知识相结合，使这项专利技术可用于PC患者。

DESCRIPTION (provided by applicant): VPAC1 Receptor-Targeted PET Imaging of Prostate Cancer Abstract Prostate cancer (PC) affects one in every six men >60 years old and will kill over 32,000 US men in 2011. Serum prostate specific antigen (PSA) measurements, transrectal ultrasonography (TRUS) and magnetic resonance imaging (MRI) remain standard tools for diagnosis and management of PC. Each of these modalities requires invasive biopsy for histologic confirmation of PC. Biopsies are associated with morbidity and high cost. More than 65% of the 1.5 million biopsies performed each year in the US show benign pathology, indicating a high false positive rate for these standard diagnostic tools. These limitations demonstrate a dire need for noninvasive methods to a) accurately stage, localized high risk primary PC, b) detect recurrent disease and c) image metastatic lesions with improved reliability. To address these issues, we propose early, specific, noninvasive radioimaging of PC. We will target VPAC1 receptors, which are overexpressed on PC cells at the onset of oncogenesis. We have successfully applied VPAC1- specific Cu-64-peptides to image prostate cancer xenografts. Our results in TRAMP transgenic mice that mimic spontaneous human PC illustrate that our Cu-64-peptides specifically and effectively target VPAC1. We have also confirmed the specificity of Cu-64 peptides for VPAC1 in MMTV-neu transgenic mice that mimic spontaneous human breast cancer (BC), including overexpression of VPAC1. We have initiated PET imaging of BC in humans using Cu-64-VPAC1 peptides with highly promising early results. Therefore, we hypothesize that PET imaging with VPAC1 receptor-specific Cu-64 peptides will expedite the diagnosis of PC and contribute to its management, including reduction in unnecessary biopsy procedures and under treatment or over treatment that yield minimal benefits, incontinence, or impotence. We will test our hypothesis in four Specific Aims: i) Evaluate two Cu-64 peptides specific for VPAC1 by imaging human PC xenografts in athymic nude mice. ii) Determine the efficacy of the best Cu-64-peptide in TRAMP transgenic mice that mimic human PC pathogenesis and validate VPAC1 imaging of PC malignancy in TRAMP mice by comparison with F-18-FDG scans, PC histology, and VPAC1 RT-PCR and immunohistochemistry. iii) Perform toxicology, obtain eIND and iv) carryout a feasibility study in 25 pre-operative PC patients, using the best suited Cu-64-peptide. PET imaging results shall be statistically evaluated with those of the histologic findings, and the entire PC gland mapping. This translational research for molecular PET imaging of PC by targeting VPAC1 will yield a PET imaging peptide validated for PC detectability and imaging specificity. Our strategic partner, NuView, offers a multidisciplinary industrial team with expertise in radiopharmaceutical development, clinical trials, and marketing strategies that ensures successful translation of this technology from bench to bedside. PUBLIC HEALTH RELEVANCE: One in six men older than sixty years will have prostate cancer (PC), yet it remains a major challenge to diagnose it accurately and reliably, resulting in undertreatment or overtreatment of patients with minimal benefit, enormous morbidity, incontinence, and/or impotence, while costing hundreds of millions of health care dollars for invasive biopsies required for confirmation of PC. We will evaluate two promising small molecules that will be injected into patients with suspected PC, which will then attach to a specific cancerous alteration that shows up on PC cell surfaces, yielding signals from the attached molecules that are collected outside the body to provide highly accurate and specific images of malignant PC. Our preliminary imaging results using these small molecules are highly promising to eliminate the present drawbacks and to allow the combined expertise of our team from Thomas Jefferson University and NuView, Inc. to make this patented technology available for the benefit of PC patients.