PROSTATE TUMOR DIAGNOSIS: BLOOD CELL MULTIGENE SIGNATURES

该子项目是利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 研究中心，而研究中心不一定是研究者所在的机构。 作为手术活检程序的先决条件，目前用于前列腺癌筛查和风险评估的技术是基于个体血清生物标志物或循环恶性细胞中个体基因表达的测量。 这些技术具有许多局限性，包括缺乏诊断的特异性和准确性，以及缺乏预后信息。 这最终产生大量的假阳性诊断，并因此产生不必要的大量手术活检。 越来越多的证据表明，患有前列腺癌和其他形式的恶性疾病的个体表现出可以在外周血中循环的白细胞中改变的基因表达水平上检测到的免疫应答。 白细胞中许多单个基因的mRNA转录物的定量已经证明了基因表达水平与肿瘤存在之间的关联。 已经显示，个体蛋白质的血清水平表现出与白细胞中的差异基因表达的一定程度的相关性，并且提供关于肿瘤阶段的一些信息。此外，我们已经启动了一项试点研究，以检查患有前列腺癌的非洲裔美国男性的基因表达水平，并与多个基因的健康对照相比，显示了多个基因的表达差异。 假设：这些观察结果构成了本研究假设和实验设计的基础。 使用微阵列技术将使我们能够同时测量来自前列腺癌患者和对照个体血液的循环白细胞中转录的多达14，000个基因的表达水平。 通过这项技术，我们提出了一个假设，即患有前列腺癌的个体在其外周血白细胞中表现出保守的基因表达水平模式或特征，这与对照受试者白细胞中相应的表达模式不同。 我们将检验进一步的假设，即具有不同组织学分级的前列腺肿瘤的癌症患者将产生不同的表达特征，其反映肿瘤的生物学阶段和侵袭性，并且因此可以用于区分不同病理学阶段的肿瘤。 整个提案的具体目标是： 具体目标一： a）在本项目的两年内收集40名前列腺癌患者和20名健康对照受试者的血液白细胞。 B）采用亲和基因芯片微阵列技术测量白细胞样品中的整体基因表达。 c）采用数据分析算法来建立可以区分前列腺癌患者和对照受试者的白细胞多基因表达特征。 具体目标二：利用在特定目标1下生成的表达数据，允许将前列腺癌患者分类为对应于前列腺肿瘤进展的特定阶段的组。 本提案的最终目标。 本文提出的研究的最终目标是开发一种不需要侵入性手术的新技术，但提供了前列腺癌的准确诊断，并提供了有关肿瘤阶段和生物侵袭性的详细预后信息。 该项目的成功将产生一个急需的，非侵入性的工具，用于前列腺癌的阶段特异性诊断，从而作为一个重要的预筛选，以确定男性前列腺肿瘤。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Current techniques for the screening and risk assessment of prostate cancer, as a prerequisite to surgical biopsy procedures, are based upon the measurement of either individual serum biomarkers, or expression of individual genes in circulating malignant cells. These techniques possess a number of limitations, including lack of specificity and accuracy in the diagnosis and, also a lack of prognostic information. This ultimately yields high numbers of false positive diagnoses, and consequently unnecessarily large numbers of surgical biopsies. There is growing evidence that individuals with prostate cancer and other forms of malignant disease, exhibit immune responses that can be detected at the level of altered gene expression in leukocytes circulating in peripheral blood. Quantitation of the mRNA transcripts in leukocytes of a number of individual genes has demonstrated associations between gene expression levels and the presence of a tumor. It has been shown that serum levels of individual proteins exhibit a degree of correlation with differential gene expression in leukocytes, and provides some information on tumor stage. Additionally, we have initiated a pilot study to examine gene expression levels in African-American men with prostate cancer, and have shown expression difference for multiple genes, compared to healthy controls of multiple genes. Hypothesis: These observations form the basis of the hypothesis and experimental design of this proposed study. The use of microarray technology will allow us to measure simultaneously the expression levels of up to 14,000 genes transcribed in circulating leukocytes derived from the blood of prostate cancer patients and control individuals. With this technology, we propose to investigate the hypothesis that individuals suffering from prostate cancer exhibit a conserved pattern, or signature, of gene expression levels in their peripheral blood leukocytes, which is distinct from the corresponding pattern of expression in leukocytes from control subjects. We will test the further hypothesis that cancer patients with prostate tumors at different histological grades, will yield distinct expression signatures that reflect the biological stage and aggressiveness of the tumor, and that can thus be employed to differentiate among tumors at different pathological stages. The Specific aims of this entire proposal are to: Specific Aim One: a) Collect Blood Leukocytes from 40 Prostate Cancer Patients and 20 Healthy Control Subjects Over the Two Year Period of This Project. b) Employ Affymetrix GeneChip Microarray Technology to Measure Global Gene Expression in the Leukocyte Samples. c) Employ Data Analysis Algorithms to Establish Leukocyte Multigene Expression Signatures that Can Distinguish Between Prostate Cancer Patients and Control Subjects. Specific Aim Two: Utilize the Expression Data Generated Under Specific Aim One, to Permit Classification of Prostate Cancer Patients into Groups Corresponding to Specific Stages of Prostate Tumor Progression. Ultimate Goal of this Proposal. The ultimate goal of the research proposed here is to develop a novel technique that does not require invasive surgery, yet provides an accurate diagnosis of prostate cancer, and also provides detailed prognostic information on the stage and biological aggressiveness of the tumor. The success of this project would yield a much needed, non-invasive tool for stage-specific diagnosis of prostate cancer of the disease, and thus serve as an important pre-screen to identify men with prostate tumors.