Impact of neurofibromin on ER-alpha and nuclear speck post-transcriptional gene regulation

项目总结 转录本的选择性剪接(AS)是一个重要的转录后过程，它是工具性的 具有多种细胞功能，包括增殖、分化和存活。AS的过程是受监管的 通过RNA结合蛋白(RBPs)及其适当的核定位和与剪接体的相互作用 形成明显致密隔间的成分称为核斑点(NS)。癌症发生的能力 通过靶向参与EMT、侵袭、细胞周期调节和转录的基因来劫持和利用AS 对照已被描述为影响转移潜能和治疗耐药。最近，它已经 研究表明，50%的乳腺癌包含至少一种RBP的过度表达或扩增 因此，靶向AS的基因转录本以诱导侵袭性特征。此外，一个新的函数 最近发现雌激素受体α(ER-α)与ER-α的非规范结合影响雌激素受体-α(ER-RNA)的表达。 转录调控和促进细胞适应环境压力的反应。我们的实验室， 最近，与其他研究人员一起，在NF1和ERα之间建立了调控ERα信号的关键链接。NF1 是一种肿瘤抑制基因，编码神经纤维蛋白，当突变时驱动 乳腺癌预后较差。这些研究激发了人们研究疾病发生机制的动力。 哪些NF1基因缺陷的乳腺癌会导致转移和内分泌抵抗。 神经纤维蛋白和ERα之间的相互作用描述了神经纤维蛋白作为一种共同的 ERα‘S转录活性的抑制因子。然而，目前仍不清楚这种神经纤维素-ERα是否 相互作用调节ERα的S转录后调控或神经纤维蛋白定位的重要性 这项规定。我的F99训练阶段的总体目标(目标1)是确定神经纤维素所起的作用 在ERα转录后调控中。具体地说，目的是1)确定神经纤维素对ERα的影响 NF1突变ER+乳腺癌模型中依赖的转录后调控和1.2)决定 选择性雌激素受体调节剂对雌激素受体α转录后调控的影响 NF1缺陷细胞。F99阶段的培训目标将扩展我的分子技术、测序、 以及癌症生物学中的数据分析。在我的K00阶段(目标2)，我将定义核的影响 神经纤维蛋白通过核斑点的形成和功能对转录后调控起作用。NF1- 缺陷乳腺癌模型将被用来确定核斑点的形成、成分和后处理。 转录和基因调控。该奖学金所产生的培训和数据将确立 为我作为独立研究员的职业生涯奠定了科学和专业技能的基础。

PROJECT SUMMARY Alternative splicing (AS) of transcripts is an essential post-transcriptional process that is instrumental for numerous cell functions including proliferation, differentiation, and survival. The process of AS is regulated by RNA binding proteins (RBPs) and their proper nuclear localization and interactions with spliceosome components which form visibly dense compartments called nuclear specks (NS). The ability for cancer to hijack and utilize AS by targeting genes involved in EMT, invasion, cell cycle regulation, and transcriptional control has been described to influence metastatic potential and therapeutic resistance. More recently, it has been shown that 50% of breast cancers contain overexpression or amplification of at least one RBP which consequently targets gene transcripts for AS to induce invasive characteristics. Furthermore, a novel function of estrogen receptor alpha (ERα) recently revealed non-canonical RNA binding of ERα to influence post- transcriptional regulation and promote cell fitness in response to environmental stressors. Our laboratory, along with other, recently established a critical link between NF1 and ERα in regulation of ERα signaling. NF1 is a tumor suppressor gene, encoding for the protein neurofibromin, that when mutated drives of a subset of breast cancers with poor prognosis. These studies have sparked motivation to investigate mechanisms in which NF1-deficient breast cancers contribute to metastasis and endocrine resistance. The interaction between neurofibromin and ERα describes neurofibromins ability to act as a co- repressor of ERα’s transcriptional activity. However, it still remains unknown whether this neurofibromin-ERα interaction regulates ERα’s post-transcriptional regulation or the importance of neurofibromin localization for this regulation. The overall goal of my F99 training phase (Aim 1) is to determine the role neurofibromin plays in ERα post-transcriptional regulation. Specifically, the Aims are 1.1) to define neurofibromin’s impact on ERα dependent post-transcriptional regulation in NF1 mutant ER+ breast cancer models and 1.2) determine the efficacy of selective estrogen receptor modulators (SERMs) to impact ERα post-transcriptional regulation in NF1-deficient cells. The training objectives in the F99 phase will expand my molecular techniques, sequencing, and data analysis in cancer biology. During my K00 phase (Aim 2) I will define the impact nuclear neurofibromin has on post-transcriptional regulation through nuclear speck formation and function. NF1- deficient breast cancer models will be used to determine nuclear speck formation, composition, and post- transcriptional and gene regulation. The training and data resulting from this fellowship award will establish the foundation of scientific and professional skills for my career as an independent researcher.