Detection of Prostate Cancer Genomic Signatures in Blood

描述（由申请人提供）：本资助申请涉及本FAO （RFA-OD-09-003）中描述的广泛挑战领域“03-生物标志物发现和验证”和具体挑战主题“03- ca - 101 -早期发现和治疗癌症的指纹”。前列腺癌（PC）的诊断通常是在常规血液中前列腺特异性抗原（PSA）测定和/或发现前列腺内可触及的肿块（直肠检查后），可以通过解剖（超声、CT）成像显示。原发肿块的性质通常由经直肠、超声指导下的前列腺活检后的组织病理学特征来确定。目前，这些肿瘤大多局限于前列腺，这些原发性肿瘤的手术切除/放射治疗是可以治愈的。然而，对于许多发生转移的患者来说，尽管有目前的治疗方法，结果是死亡。造成高死亡率的一个主要因素是，在出现病理体征和症状之前，我们无法在最早/最可治愈的阶段识别男性原发性和转移性隐匿性PC病变的存在。虽然目前的血液检测（如PSA）在诊断和治疗监测中继续发挥一定作用，但其特异性、敏感性和准确性仍然不足。我们假设，困扰这一和其他癌症检测的假阳性和假阴性率是由于它们无意中依赖于从“健康”男性血液中获得的群体衍生的平均基因组/蛋白质组特征谱，即基线/背景特征是/不是特定于被测个体的基因组成。最近，我们提出，从同一个体获得的吞噬性和非吞噬性白细胞非常适合于“肿瘤特异性”和“正常特异性”特征的简单识别和区分，因此，消除了由于个体间内在的“基线不平等”（例如，年龄、性别、种族背景、健康状况）和基因表达的时间差异。独特的是，该方法不依赖于从“健康”对照中获得的种群平均特征谱和/或生物标志物值。该方法声称，对吞噬性白细胞的DNA、RNA、蛋白质和/或脂质表达谱进行分析，并将其与来自同一供体的非吞噬性白细胞的DNA、RNA、蛋白质和/或脂质表达谱进行比较，将导致在吞噬细胞内识别肿瘤特异性特征（患者特异性信号），这些特征在非吞噬细胞中不表达或最低限度地表达（患者特异性噪声）。我们在荷瘤小鼠和少数癌症患者中的初步研究完全支持我们的预期，并表明(i)多种癌基因和肿瘤特异性基因组特征在吞噬细胞中被选择性地获得/表达；（ii）这些基因在非吞噬细胞中不表达或最低限度表达；（iii）迄今为止，该试验在所有情况下都能区分(a)荷瘤小鼠与非荷瘤小鼠，(b)癌症患者与正常献血者。在本次拨款申请中提出的研究中，我们计划在已知患有PC的男性的血液样本中验证这种独特的方法，并证明新开发的新型血液检测方法(1)可以区分已知患有PC的患者和健康个体（献血者），(2)将导致识别特定于PC的基因组特征，并普遍预测隐匿性和/或复发性疾病的存在。我们相信，我们的研究——在成功验证PC患者的血液分析后——将导致发现一个基因阵列（带有已识别的基因组特征），该基因阵列将(i)用于PC的常规检测/诊断，（ii）用于识别疾病复发。因此，我们期望血液测试对在美国和全世界根除PC的目标产生前所未有的高影响，并作出重大贡献。项目描述：目前基于血液的细胞和分子检测的特异性、敏感性、可重复性和/或准确性是不足的。我们假设，困扰这些检测的假阳性和假阴性率是它们依赖于从“健康”对照者的血液中获得的人群衍生的平均特征谱的结果，即基线/背景特征是/不是特定于被测个体的基因组成。在这项挑战资助申请中，我们描述了在已知患有前列腺癌的男性白细胞中识别肿瘤特异性特征的方法。

DESCRIPTION (provided by applicant): This grant application addresses the Broad Challenge Area "03 - Biomarker Discovery and Validation" as described within this FAO (RFA-OD-09-003) and the Specific Challenge Topic "03-CA- 101 - Fingerprints for the early detection and treatment of cancer". The diagnosis of prostate cancer (PC) is usually subsequent to routine prostate-specific antigen (PSA) determination in blood and/or discovery of a palpable mass within the prostate (following rectal examination) that may be visualized by anatomic (US, CT) imaging. The nature of the primary masses is generally affirmed by histopathologic characterization following an invasive transrectal, ultrasound-directed, prostatic biopsy. At presentation, the majority of these tumors are localized in the prostate and surgical removal/radiation of these primary tumors can be curative. However, for many of the patients who develop metastases, despite current therapies, the outcome is death. A principal factor contributing to the high mortality rate is our inability to identify the presence of primary and metastatic occult PC lesions in men at the earliest/most curable stage, prior to the manifestation of pathologic signs and symptoms. While current blood-based assays (e.g., PSA) continue to play some role in diagnosis and in treatment monitoring, their specificity, sensitivity, and accuracy continue to be inadequate. We postulate that the false-positive and false-negative rates which have plagued this and other cancer assays are a consequence of their inadvertent dependence on population-derived, average genomic/ proteomic signature profiles that are obtained from the blood of "healthy" men, i.e., the baseline/ background signature(s) is/are NOT specific to the genetic makeup of the individual being tested. Recently, we proposed that phagocytic and nonphagocytic WBC - obtained from the same individual - are ideally suited to the facile identification and differentiation of "tumor-specific" and "normal- specific" signatures and, therefore, the elimination of the "inequality of baseline" consequent to the intrinsic interindividual (e.g., age, gender, ethnic background, health status) and temporal variation in gene expression. Uniquely, the approach does not depend on population-derived average signature profiles and/or biomarker values obtained from "healthy" controls. The approach claims that the analysis of DNA, RNA, protein, and/or lipid expression profiles of phagocytic WBCs and their comparison with those from nonphagocytic WBCs of the same donor will lead to the identification of tumor-specific signatures within the phagocytic cells (patient-specific signal) that are not expressed or minimally expressed in the nonphagocytic cells (patient-specific noise). Our preliminary studies in tumor-bearing mice and in a few cancer patients fully support our expectations and show that (i) multiple oncogenes and tumor-specific genomic signatures are selectively acquired/expressed within phagocytic cells; (ii) these genes are not expressed or are minimally expressed in nonphagocytic cells; and (iii) the assay - thus far in all instances - differentiates (a) tumor-bearing mice from non-tumor bearing mice, and (b) cancer patients from normal blood donors. In the studies proposed in this grant application, we plan to validate this unique approach in blood samples obtained from men known to have PC and demonstrate that the newly-developed novel blood assay (i) can differentiate between patients known to have PC and healthy individuals (blood donors), and (ii) will lead to the identification of genomic signatures that are specific to PC and are universally predictive of the presence of occult and/or recurring disease. We trust that our studies - upon successful verification of the blood assay in PC patients - will lead to the discovery of a gene array (spotted with the identified genomic signatures) that will (i) be used for the routine detection/diagnosis of PC, and (ii) be employed to identify disease recurrence. Consequently, we expect the blood test to have an unprecedentedly high impact on, and contribute significantly to, the goal of eradicating PC in the USA and worldwide. PROJECT NARRATIVE: The specificity, sensitivity, reproducibility, and/or accuracy of current blood-based cellular and molecular assays are inadequate. We postulate that the false-positive and false-negative rates that have plagued these assays are a consequence of their dependence on population-derived, average signature profiles obtained from the blood of "healthy" controls, i.e., the baseline/background signature(s) is/are NOT specific to the genetic makeup of the individual being tested. In this Challenge grant application, we describe methods for the identification of tumor-specific signatures within the WBCs of men known to have prostate cancer.