Translesion DNA polymerase kappa activity in gliomas

描述(由申请人提供)：跨损伤DNA合成聚合酶(TLS Pols)对绕过和耐受DNA损伤至关重要。TLS Pols的异常调节可见于许多类型的癌症，包括源于神经胶质细胞的恶性脑瘤。人类脱氧核糖核酸聚合酶kappa(hPol-κ)最近被证明是脑胶质瘤患者预后不良的独立预后指标。然而，导致hpolDNA在胶质瘤中上调的机制(S)以及对κ复制的确切影响仍不清楚。本文概述的实验将检验芳香烃受体(AhR)的促肿瘤激活是否会导致胶质瘤中hPollκ的结构性上调，然后研究与这些致命肿瘤中hPollκ活性相关的机制特征。中心目标包括研究促进人脑胶质瘤细胞hPollκ过度表达的机制，确定这种错误调控对复制应激反应的影响，研究改变hPollκ活性的蛋白质-蛋白质相互作用，以及研究通过靶向抑制脑瘤中的TLSPO来改善脑胶质瘤治疗的潜在方法。目前的建议将解决一些重要的问题，如：1)AhR通路是否调节胶质瘤中hpolDNA的表达？2)外源性或内源性AhR配体是否影响hPolDNA的表达和/或活性？3)阻断胶质瘤内源性AhR信号通路如何影响复制应激？4)调节胶质瘤中的Tls活性是否能增强抗癌治疗？5)hpolDNA与基因组看守沃纳综合征蛋白之间的蛋白-蛋白质相互作用是否限制了胶质瘤细胞中κ损伤的突变旁路？实验策略利用体外细胞培养、突变分析、结构-功能分析、小分子抑制物研究和蛋白质组学来确定hPollκ在胶质瘤中的作用。该应用程序的长期目标是建立复制应激和TLS活性的模型，使我们能够了解胶质瘤的基因组维护和突变，同时也为我们如何更好地治疗这种疾病的患者提供见解。这些研究得出的结论将极大地改善我们对恶性脑瘤过程的基本定义，恶性脑瘤是一个主要的公共卫生问题。

DESCRIPTION (provided by applicant): Translesion DNA synthesis polymerases (TLS pols) are vital to bypass and tolerance of DNA damage. The mis-regulation of TLS pols occurs in many types of cancer, including malignant brain tumors of glial origin. Human DNA polymerase kappa (hpol κ) was recently shown to be an independent prognostic indicator of poor outcome in glioma patients. However, the mechanism(s) leading to up-regulation of hpol κ in gliomas and the precise effects upon DNA replication remain unknown. The experiments outlined herein will examine whether tumor-promoting activation of the aryl hydrocarbon receptor (AhR) leads to constitutive up-regulation of hpol κ in gliomas and then investigate mechanistic features associated with hpol κ activity in these deadly tumors. The central objectives include investigating mechanisms that promote hpol κ over-expression in glioma cells, determining the effect of this mis-regulation upon replication stress responses, studying protein-protein interactions that alter hpol κ activity and examining potential ways of improving glioma treatment through targeted inhibition of TLS pols in brain tumors. The current proposal will address important questions, such as: 1) Does the AhR pathway regulate hpol κ in gliomas? 2) Do exogenous or endogenous AhR ligands affect hpol κ expression and/or activity? 3) How does blocking endogenous AhR-signaling in gliomas affect replication stress? 4) Can modulation of TLS activity in gliomas potentiate anti-cancer treatments? 5) Do protein-protein interactions between hpol κ and the genomic caretaker Werner's syndrome protein (WRN) limit mutagenic bypass of DNA damage in glioma cells? The experimental strategies utilize in vitro cell culture, mutagenesis assays, structure-function analyses, small-molecule inhibitor studies and proteomics to ascertain the role of hpol κ in gliomas. The long-term goal of the application is to produce models for replication stress and TLS activity that inform our understanding of genomic maintenance and mutagenesis in gliomas, while also providing insights into how we might better treat patients suffering from this disease. The conclusions derived from these studies will dramatically improve our fundamental definition of processes that occur in malignant brain tumors, a major public health concern.