Elucidating the role of somatic 3’UTR mutations in prostate cancer pathogenesis

项目摘要 前列腺癌是第二个最常见的原因癌症死亡率在美国男子由于我们的认识不足 和治疗转移性去势抵抗性前列腺癌（mCRPC）。新的见解的机制 前列腺癌的发病机理可以在历史上未充分研究的基因表达方面中发现， 包括癌基因的转录后调节。一种重要的转录后基因调节因子 调节是3'非翻译区（3' UTR），其在控制mRNA稳定性和 翻译. 3 'UTR在癌症患者中具有显著的突变负担;然而，这些突变在癌症患者中并不重要。 还没有被广泛研究。个体3 'UTR变异与癌症风险相关， 在报告基因测定中调节表达，但仍不清楚这些突变是否显著影响 患者的发病机制以及这种失调在癌症中的普遍程度。通过执行体细胞 通过对230名前列腺癌患者的独特队列进行研究，我发现了超过13，000个3 'UTR体细胞突变， 癌症组织中的基因组突变。其中许多是在已知的癌症相关基因和3 'UTR 调控基序，表明它们有可能影响致癌表达和癌症发病机制。 此外，我已经通过患者样本子集的核糖体分析确定，约40%的3 'UTR 突变与转录后基因调控的变化有关。使用个体报告基因测定， 我已经证实，这些患者识别的已知癌症相关基因中的几个3 'UTR突变 显著改变基因表达。这些功能突变之一是PAK 2，一种p21激活的激酶， 在细胞运动中，其过度活化在几种癌症中是致癌的。根据这些初步数据，我 假设3 'UTR突变驱动转录后基因调控中的致癌变化，例如 PAK 2的过度表达导致前列腺癌患者发病。我现在的目标是定义 这种PAK 2 3 'UTR突变增加PAK 2表达的分子和致病机制， 使用突变的内源细胞系模型在体外和体内加剧癌性表型。 此外，我将通过以下方法研究癌症中3 'UTR突变介导的基因失调的程度： 一种平行的报告基因测定，以确定> 6，000个患者鉴定的3 'UTR突变对 转录水平和翻译效率。这些研究将确定3 'UTR突变作为基因突变的重要驱动因素。 致癌失调，扩大功能性癌症基因组学领域和我们对前列腺的理解 癌症发病机制，除了潜在地确定新的治疗靶点。

PROJECT SUMMARY Prostate cancer is the second most common cause of cancer mortality in US men due to our poor understanding and treatment of metastatic, castration-resistant prostate cancer (mCRPC). New insights into mechanisms of prostate cancer pathogenesis may be found within historically understudied aspects of gene expression, including post-transcriptional regulation of oncogenes. An important mediator of post-transcriptional gene regulation is the 3’ untranslated region (3’UTR), which plays critical roles in controlling mRNA stability and translation. The 3’UTR harbors a significant mutational burden across cancer patients; however, these mutations have not been extensively studied. Individual 3’UTR variants have been associated with cancer risk and shown to regulate expression in reporter assays, but it is still unclear whether these mutations significantly affect pathogenesis in patients and how widespread this dysregulation may be across cancer. By performing somatic mutation calling on a unique cohort of 230 prostate cancer patients, I have uncovered over 13,000 3’UTR somatic mutations in cancer tissues genome-wide. Many of these are in known cancer-related genes and 3’UTR regulatory motifs, indicating they have potential to affect oncogenic expression and cancer pathogenesis. Furthermore, I have determined via ribosome profiling of a subset of patient samples that ~40% of 3’UTR mutations are associated with changes in post-transcriptional gene regulation. Using individual reporter assays, I have validated that several of these patient-identified 3’UTR mutations in known cancer-related genes significantly alter gene expression. One of these functional mutations is in PAK2, a p21-activated kinase involved in cell motility, hyperactivation of which is oncogenic in several cancers. Based on these preliminary data, I hypothesize that 3’UTR mutations drive oncogenic changes in post-transcriptional gene regulation, such as overexpression of PAK2, that contribute to pathogenesis in prostate cancer patients. I now aim to define the molecular and pathogenic mechanisms by which this PAK2 3’UTR mutation increases PAK2 expression and exacerbates cancerous phenotypes in vitro and in vivo using an endogenous cell line model of the mutation. Additionally, I will investigate the extent of 3’UTR mutation-mediated gene dysregulation in cancer by performing a massively-parallel reporter assay to determine the effects of >6,000 patient-identified 3’UTR mutations on transcript levels and translation efficiency. These studies will establish 3’UTR mutations as important drivers of oncogenic dysregulation, expanding the field of functional cancer genomics and our understanding of prostate cancer pathogenesis, in addition to potentially identifying new therapeutic targets.