The Role of MicroRNAs in Prostate Cancer Progression

描述(由申请人提供)： 前列腺癌是美国男性最常见的癌症形式。去年，这种流行的疾病导致了约27,000人死亡，男性死亡率仅次于肺癌。前列腺特异性抗原(PSA)是前列腺癌的一种广泛使用的诊断标记物，可以治疗一些微不足道的疾病，部分原因是PSA是组织特异性的，而不是前列腺癌特异性的。因此，需要更准确的生物标志物，有可能与PSA联合使用，以帮助前列腺癌的早期诊断。一类长度约22个核苷酸的非编码小RNA，称为microRNAs(MiRNAs)，在人类癌症中经常错误表达，并被认为具有肿瘤抑制和癌基因的功能。然而，关于这些分子如何直接促进细胞转化和癌症进展，或者miRNA失控如何与前列腺癌有关，人们知之甚少。具体目的：需要检验的假设是，在疾病状态下，控制前列腺内适当细胞生长和分化的miRNAs将被解除调控，因此miRNA错误表达将与前列腺癌进展的早期阶段和微转移疾病密切相关。我们特别期待识别进化保守的Lin-4和let-7 miRNA家族的成员，我们已经证明这两个家族控制动物的基本发育事件，并与人类癌症有关。这项建议将1)通过miRNA微阵列分析和实时定量聚合酶链式反应，从大量(~250)前列腺癌患者(包括微小疾病和微转移疾病)患者的组织样本中识别解除调控的miRNAs；2)使用生物信息筛选和报告基因分析，确定前列腺癌相关miRNAs的基因靶点；3)通过对正常和疾病前列腺组织标本的原位表达分析和对人前列腺细胞系的miRNA错误表达研究，分析其对生长调节和细胞转化的影响，以探讨这些与前列腺癌相关的miRNA-靶相互作用是否直接参与癌症的进展。这项提议的总体目标是识别可以作为前列腺癌早期检测生物标志物的miRNA基因，并确定这些miRNAs及其潜在靶点如何控制该组织中的肿瘤形成。研究miRNAs在前列腺癌进展中的作用有望揭示发现和治疗这种流行疾病的新策略。

DESCRIPTION (provided by applicant): Prostate cancer is the most common form of cancer in males within the United States. This prevalent disease was responsible for ~27,000 deaths last year, a mortality rate in men second only to lung cancer. Prostate-specific antigen (PSA) is a widely used diagnostic marker for prostate cancer that can result in the treatment of insignificant disease due in part because PSA is tissue specific but not prostate cancer specific. Therefore, more accurate biomarkers, potentially used in combination with PSA, are required to aid in the early diagnosis of prostate cancer. An abundant class of small non-coding RNAs of ~22 nucleotides in length, referred to as microRNAs (miRNAs), are often misexpressed in human cancers and implicated to function as tumor suppressors and oncogenes. However, little is known regarding how these molecules directly contribute to cellular transformation and cancer progression or how miRNA deregulation relates to prostate cancer. SPECIFIC AIMS: The hypothesis to be tested is that miRNAs controlling proper cellular growth and differentiation in the prostate will be deregulated in the diseased state and thus miRNA misexpression will closely correlate with early stages of prostate cancer progression and micrometastatic disease. We particularly anticipate identifying members of the evolutionary conserved lin-4 and let-7 miRNA families, which we have shown control essential developmental events in animals and are linked with human cancers. This proposal will 1) identify miRNAs that are deregulated in a large cohort (~250) of tissue samples taken from patients with prostate carcinomas including insignificant and micrometastatic disease compared to non-cancerous specimens from benign prostatic hyperplasia (BPH) patients and normal prostate tissues via miRNA microarray analysis and quantitative real-time PCR; 2) determine the gene targets of prostate cancer-associated miRNAs that direct oncogenic events using bioinformatic screens and reporter gene assays; and 3) investigate if these prostate cancer-associated miRNA-target interactions are directly involved in cancer progression by in situ expression analysis on normal and diseased prostate tissue specimens and miRNA misexpression studies in human prostate cell lines to analyze resulting affects on growth modulation and cellular transformation. The overall goal of this proposal is to identify miRNA genes that could serve as early detection biomarkers for prostate cancer and to determine how these miRNAs and their potential targets control tumor formation in this tissue. Investigating the function of miRNAs in prostate cancer progression promises to reveal novel strategies to detect & treat this prevalent disease.