EARLY DETECTION OF URINARY BLADDER CANCER

描述（由申请人提供）：本项目的总体目标是开发新的生物标志物和诊断策略，用于早期检测隐匿性膀胱肿瘤及其从尿路上皮内癌前病变进展为浸润性癌症。目前的建议是早期发现研究网络第一周期期间进行的研究的延伸和逻辑延续。这些研究已经导致了对膀胱癌发展至关重要的六个染色体区域的鉴定，并且提供了被称为“先驱”的一类新基因的存在的证据，其参与在癌症发展中的主要肿瘤抑制基因的功能丧失之前。我们假设膀胱癌前病变的原位克隆性扩张是由与已知的主要肿瘤抑制因子（如RB 1）相邻的前导基因功能丧失引起的。我们利用短干扰RNA的体外研究提供的证据表明，这些基因的功能丧失对尿路上皮细胞的生长优势至关重要。因此，新的先导基因的鉴定和它们参与人类膀胱癌前病变的早期隐匿阶段的调查不仅可以为人类癌症的发展提供重要的机制线索，而且还可以鉴定能够检测人类癌症发展的临床和显微镜下隐匿阶段的一类新的早期检测标记物。我们还假设了膀胱癌进展的一种补充机制，该机制基于最近发现的致癌激酶STK 15/BTAK/Aurora-A的扩增和过表达，该激酶参与调节染色体分离和中心体功能，最近能够使p53肿瘤抑制蛋白不稳定。在这项补助金中，我们提出了以下主要研究组： (1)对已经确定的推定的“先导基因”（ITM 2B、P2 RY 5和CHClL）进行功能分析和评估，这些基因位于RB 1附近，作为新的早期检测生物标志物。此外，我们建议对染色体17 p13和5 q22 -23上其他预测的先导基因定位进行表征，并评估被鉴定为膀胱癌检测生物标志物的候选基因。我们还将研究遗传和表观遗传机制在每个基因的功能失活中的贡献，以阐明先导基因在恶性转化过程中的作用的全面观点，这将提高我们检测先导基因的能力，并提供临床相关的标记物用于早期检测。 (2)我们对STK 15/BTAK/Aurora-A及其相互作用基因作为膀胱癌检测生物标志物的研究进行了扩展。 (3)在一项前瞻性验证试验中，将联合收割机STK 15/BTAK/Aurora-A及其监管合作伙伴与约15种标志物的先导基因组合，以测试其识别隐性膀胱肿瘤的能力。 由于两大类新基因，即先导基因和Aurora-A及其伙伴，似乎普遍参与人类致癌作用，该项目的完成将对其他常见人类癌症的早期检测具有重大意义。

DESCRIPTION (provided by applicant): The overall goal of this project is to develop novel biomarkers and diagnostic strategies for the early detection of occult urinary bladder neoplasia and its progression from intraurothelial preneoplastic conditions to invasive cancer. The current proposal represents an extension and logical continuation of the studies performed during the first cycle of the Early Detection Research Network (EDRN). These studies have led to the identification of six chromosomal regions critical for the development of bladder cancer and have provided evidence for the existence of a novel class of genes referred to as "forerunners" whose involvement precedes the loss of function of major tumor suppressor genes in the development of cancer. We hypothesize that in situ clonal expansion of bladder preneoplasia is caused by loss of function of the forerunner genes mapping contiguously to known major tumor suppressors such as RB1. Our in vitro studies utilizing short interference RNA provide evidence that loss of function of these genes is critical for growth advantage of urothelial cells. Thus, the identification of novel forerunner genes and the investigation of their involvement in early occult phases of human bladder preneoplasia may not only provide important mechanistic clues to the development of human cancer but may also identify a novel class of early detection markers capable of detecting the clinically and microscopically occult phases of human cancer development. We also hypothesized a complementary mechanism of bladder cancer progression based on the amplification and overexpression of a recently identified oncogenic kinase STK15/BTAK/Aurora-A shown to be involved in regulating chromosomal segregation and centrosome function and more recently to be capable of destabilizing the p53 tumor suppressor protein. In this grant we propose the following major groups of studies: (1) Perform functional analyses and assessment of the already identified putative "forerunner genes" (ITM2B, P2RY5, and CHClL) located contiguously to RB1 as novel early detection biomarkers. Additionally, we propose to characterize other predicted forerunner gene harboring loci mapping on chromosomes 17p13 and 5q22-23 and to assess the candidate genes identified as biomarkers for bladder cancer detection. We will also investigate the contribution of genetic and epigenetic mechanisms in the functional inactivation of each of the genes to elucidate a comprehensive view of the role of forerunner genes in the malignant transformation process that will enhance our ability to detect forerunner genes and provide clinically relevant markers for early detection. (2) Extension of our studies on STK15/BTAK/Aurora-A and its interacting genes involved in the pathway as biomarkers for bladder cancer detection. (3) Combine the STK15/BTAK/Aurora-A and its regulatory partners with the forerunner genes in a panel of approximately 15 markers testing their ability to identify occult bladder neoplasia in a prospective validation trial. Since both major categories of novel genes, i.e. the forerunner genes and Aurora-A with its partners, appear to be universally involved in human carcinogenesis the completion of this project will have major relevance for early detection of other common human cancers.