Role of RNase L in the Biology of Prostate Cancer

描述(申请人提供)：最近，干扰素抗病毒途径和前列腺癌遗传学的研究令人惊讶地集中在核糖核酸酶L(核糖核酸酶L)上，这是一种独特的受调控的酶，需要5‘-三磷酸，2’，5‘-连接的寡腺苷酸盐(2-5A)才能发挥活性。遗传性前列腺癌1(HPC1)家系中RNASE基因的种系突变和肿瘤组织中杂合性缺失(LOH)的存在提示了核糖核酸酶L在前列腺癌发病机制中的新作用。我们的初步数据表明，核糖核酸酶L参与了介导前列腺癌细胞凋亡的过程，并提示核糖核酸酶L在小鼠体内具有肿瘤抑制作用。我们建议通过细胞培养和动物模型以及从前列腺癌患者中提取的RNA来研究核糖核酸酶L在前列腺癌中的基础作用。我们的假设是，核糖核酸酶L通过影响细胞生长和凋亡之间的平衡来抑制前列腺癌的发展。我们的研究目的是：(1)研究干扰素和雄激素对前列腺癌细胞2-5A/核糖核酸酶L系统的调节作用，鉴定前列腺癌核糖核酸中2-5A合成酶的病毒和/或细胞核糖核酸激活子；(2)在病毒感染、双链RNA治疗或雄激素剥夺前，通过短干扰RNA下调前列腺癌细胞中核糖核酸酶L和核糖核酸酶L抑制物的水平，并探讨其凋亡信号转导途径；(3)研究核糖核酸酶L对野生型或缺失RNASE L小鼠前列腺生物学的影响，同时研究与前列腺癌发病相关的其他基因缺失(P53和NKX3.1)或双链RNA介导的细胞凋亡(蛋白激酶PKR)。 HPC1与RNASE基因的定位以及RNASE基因突变与前列腺癌风险的关系为这些研究提供了依据。这项提案中描述的实验描述了一个以前从未探索过的研究领域，它可能会使我们更接近了解前列腺癌的分子基础的最终目标。

DESCRIPTION (provided by applicant): Recently, the interferon (IFN) antiviral pathways and prostate cancer genetics and have surprisingly converged on ribonuclease L (RNase L), a uniquely regulated enzyme that requires 5'-triphosphoryl, 2',5'- linked oligoadenylates (2-5A) for its activity. The presence of both germline mutations in RNASEL segregating with disease within hereditary prostate cancer 1 (HPC1)-affected families and loss of heterozygosity (LOH) in tumor tissues point to a novel role for RNase L in the pathogenesis of prostate cancer. Our preliminary data implicate RNase L in mediating prostate cancer cell apoptosis and suggest that RNase L functions as a tumor suppressor in mice. We propose to study the fundamental role of RNase L in prostate cancer using cell culture and animal models and in RNA isolated from prostate cancer patients. Our hypothesis is that RNase L suppresses development of prostate cancer by affecting the balance between cell growth and apoptosis. Our specific aims are to: (1) study regulation of the 2-5A/RNase L system by IFN and androgen in prostate cancer cells and to identify viral and/or cellular RNA activators of 2-5A synthetase in prostate tumor RNA; (2) downregulate RNase L and RNase L inhibitor (RLI) levels with short interfering RNAs (siRNAs) in prostate cancer cells prior to viral infection, dsRNA treatment or androgen deprivation and probe the apoptotic signaling pathway; and (3) study the effect of RNase L on prostate biology in mice that are wild type or deficient in RNASEL in combination with loss of other genes implicated in prostate cancer pathogenesis (p53 and NKX3.1) or dsRNA mediated apoptosis (protein kinase PKR). Mapping of HPC1 to RNASEL and the association of RNASEL mutations with prostate cancer risk provide the justification for these studies. The experiments described in this PROPOSAL describe a previously unexplored area of research that may bring us closer to the eventual goal of understanding a molecular basis for prostate cancer.