Functional Analysis of the BAP1 Metastasis Suppressor Gene in Uveal Melanoma

描述(申请人提供)：葡萄膜黑色素瘤(UM)是最常见的原发眼癌，预后和发病率都很差。UM通常转移，主要转移到肝脏，转移的肿瘤通常是致命的。肿瘤的基因图谱使肿瘤可以细分为低转移风险(1类)和高转移风险(2类)变体，然而，直到最近，这种转移倾向的遗传基础还不清楚。2010年11月下旬，港湾等人。报道称，肿瘤抑制基因BAP1在84%的1类转移瘤中发生突变。BAP1直接控制UM的转移表型，如野生型BAP1表达的消融所示。BAP1控制UM转移表型的机制尚不清楚。BAP1最早是由Rauscher实验室于1998年发现的，我们证明它具有肿瘤抑制活性，并催化泛素水解。最近的研究表明，BAP1通过参与控制细胞分化和发育的多蛋白复合体来参与基因调控。因此，BAP1可能通过表观遗传介导的基因调控来控制转移表型。在这项研究中，我们将通过将BAP1在体外和UM动物模型中的生物学和转录作用联系起来，从而为UM的转移控制提供机制基础，具体目的如下：1)通过细胞培养和动物模型确定BAP1在葡萄膜黑色素瘤转移中的作用。2)确定在建立和维持转移表型过程中受BAP1影响的基因谱。3)确定含有BAP1的多梳复合体直接靶向染色质的启动子。4)明确UM细胞中BAP1多蛋白复合体的组成和功能，及其在基因调控、泛素水解和BAP1生物学功能中的作用。这些实验将为BAP1抑制肿瘤转移提供机制基础，并验证其作为控制葡萄膜黑色素瘤发病机制的关键靶点。

DESCRIPTION (provided by applicant): Uveal Melanoma (UM) is the most common form of primary eye cancer and is associated with very poor prognosis and morbidity. UM often metastasizes, primarily to the liver and metastatic tumors are uniformly fatal. Gene profiling of tumors has allowed subdividing UMs into Low Metastatic risk (Class 1) and High Metastatic risk (Class 2) variants however, until recently, the genetic basis for this metastatic propensity was unclear. In late November of 2010, Harbour et al. reported that the tumor suppressor gene, BAP1 is mutated in 84% of Class 1 metastatic tumors. BAP1 directly controls the metastatic phenotype of UM as shown by ablation of wild type BAP1 expression. Nothing is known of the mechanism by which BAP1 controls the metastatic phenotype in UM. BAP1 was originally discovered in 1998 by the Rauscher Laboratory We showed that it possessed tumor suppressor activity and catalyzes ubiquitin hydrolysis. Recent work has shown that BAP1 participates in gene regulation by participating in multi-protein complexes which control cell differentiation and development. Thus, BAP1 likely controls the metastatic phenotype via epigenetic mediated gene regulation. In this proposal we will provide a mechanistic basis for the control of metastasis in UM by connecting the biological and transcriptional roles of BAP1 in in vitro and animal models of UM by performing the following specific aims: 1) Define the role of BAP1 in metastasis of uveal melanoma using cell culture and animal models. 2) Identify the spectrum of genes influenced by BAP1 during establishment and maintenance of the metastatic phenotype. 3) Identify Promoters which are directly targeted in chromatin by the BAP1-containing polycomb complex. 4) Define the composition and functions of the BAP1 multiprotein complex in UM cells and its role in gene regulation, ubiquitin hydrolysis and biologic functions of BAP1. These experiments will provide a mechanistic basis for metastasis suppression by BAP1 and validate it as a key target for controlling the pathogenesis of Uveal Melanoma.