Genomic Instability and Etiology of Estrogen Oncogenesis

描述（由申请人提供）：DCIS和侵袭性散发性乳腺癌（BC）的一个标志性特征是其肿瘤细胞的高水平染色体不稳定性（CIN）和非整倍体。然而，到目前为止，CIN和非整倍性尚未与雌激素(E)的作用直接相关。本提案的目的是在一个独特但相关的动物肿瘤模型中确定E诱导CIN和非整倍体的机制，即E诱导的仓鼠肾恶性肿瘤（HTK）。具体目标1。确定在E诱导HTK发育过程中持续过表达/扩增的细胞周期成分（细胞周期蛋白E、D家族、B1）和调节因子（MDM2、DHFR）。这些基因/蛋白已被证明在体外系统中引发CIN，并且是E. SPECIFIC AIM介导的c-myc/MYC过表达/扩增的下游靶点。确定早期e诱导HTK癌变过程中检测到的CIN是否由细胞周期蛋白结合引起的中心体扩增引起。cdk复合物和其他细胞周期调节剂纯化HTK中心体及其蛋白。这些研究将为启动中心体扩增的机制提供证据，从而为这些周期蛋白的CIN和非整倍性提供证据。CDK复合物和某些细胞周期调节剂优先结合特定的中心体蛋白，或同一中心体蛋白上的不同位点。另一个目标是确定HTK发育早期中心体扩增的最早时间外观。具体目标3。确定中心体扩增（在Sp. Aim 2中进行的数据）是否发生在CIN和非整倍体之前或作为它们的结果。这是阐明HTKs中CIN和非整倍性机制的关键问题。该研究的主要目的是根据e治疗的持续时间和HTK病灶大小（体积）确定早期HTK位点中CIN最早的时间表现；对最早出现的中心体扩增使用相同的标准。第二个目标是确定在HTK发展的早期阶段参与CIN或生长优势的候选基因，采用相同的技术和HTK位点的LCMD和dopp - pcr产生的DNA样本进行跨物种微阵列分析。

DESCRIPTION (provided by applicant): A hallmark characteristic of DCIS and invasive sporadic breast cancer (BC) is the high level of chromosomal instability (CIN) and aneuploidy in its tumor cells. However, CIN and aneuploidy have not been, until now, directly related to estrogen (E) action. The goal of this proposal is to determine the mechanism whereby E elicits CIN and aneuploidy in a unique, but relevant animal tumor model, the E-induced malignant tumors in the hamster kidney (HTK). SPECIFIC AIM 1. To determine the cell cycle components (cyclins E, D family, B1) and modulators (MDM2, DHFR) which exhibit sustained overexpression/amplification during E-induced HTK development. These genes/proteins have been shown to elicit CIN in in-vitro systems, and are downstream targets of c-myc/MYC overexpression/amplification mediated by E. SPECIFIC AIM 2. To determine whether the CIN detected during early E-induced HTK oncogenesis is caused by centrosome amplification resulting from the binding of cyclin.cdk complexes and other cell cycle modulators to purified HTK centrosomes and their proteins. These studies will provide evidence for a mechanism for initiating centrosome amplification, and hence CIN and aneuploidy in which these cyclin.cdk complexes and certain cell cycle modulators bind preferentially to specific centrosome proteins, or to different sites on the same centrosome protein. Another goal is to determine the earliest temporal appearance of centrosome amplification during early stages of HTK development. SPECIFIC AIM 3. To determine whether centrosome amplification (data performed in Sp. Aim 2) occurs before CIN and aneuploidy or as a consequence of them. This is a key issue in elucidating the mechanism of CIN and aneuploidy in HTKs. A major goal of this specific aim is to determine the earliest temporal appearance of CIN in early HTK loci, based on duration of E-treatment and HTK foci size (volume); using the same criteria for the earliest appearance of centrosome amplification. A second goal is to identify candidate genes that are involved in either CIN or growth advantage in the earliest stages of HTK development, employing the same techniques and DNA samples generated from LCMD and DOP-PCR of HTK loci to be subjected to cross-species mircoarray analysis.