Dissecting the molecular mechanisms of PRC2 dysregulation in cancer

项目摘要/摘要 染色质景观控制着在癌症中改变的基本细胞功能，包括 基因组结构、基因表达和发育途径。有趣的是，表观遗传失调 染色质是癌症的一个新的标志。这些表观遗传变化反过来又使癌细胞高度依赖 在染色质机制上维持其恶性状态，从而为治疗创造机会 通过靶向染色质修饰物进行干预。受了解基本机制的愿望所驱动 作为表观遗传调控的基础，我的目标是解决分子生物学和 为推进癌症预防和治疗作出贡献。组蛋白翻译后修饰 (PTM)是染色质过程的中央调节因子，编码染色质因子的基因高度突变 在一系列癌症中。这个项目试图了解多梳抑制复合体2(PRC2)的作用。 在癌症的发展过程中。PRC2是一个主要的表观遗传机制，负责维持 异染色质和催化组蛋白H3赖氨酸27甲基化。 该提案的F99阶段的重点是研究通过以下方式调节PRC2酶活性 其EZH2亚基的高度保守的SANT1样结合(SBD)结构域。尽管有广泛的理解 在PRC2的功能和调控中，EZH2的N端SBD的分子作用尚不清楚。这个 初步数据揭示了该结构域在H3K27甲基化催化中的新机制。 令人惊讶的是，EZH2中SBD结构域的部分缺失(SbD-EZH2)会导致全球范围内抑制作用的丧失 H3K27me2和H3K27me3，在表观基因组水平上表现为EZH2的完全缺失。在 在论文余下的工作中，我的主要研究工作将指向描绘监管 EZH2-SBD结构域在变构激活PRC2酶活性中的意义 确定携带EZH2功能增益突变的淋巴瘤患者的潜在抑制机制。 该项目的K00阶段将重点研究PRC2损失在开发 高侵袭性恶性周围神经鞘瘤(MPNSTs)。有趣的是，失去PRC2 成分参与了散发性MPNST和放射相关MPNST的恶性形成。因此，要 为了进一步了解这些肿瘤的分子机制，我计划扩大我的技术专长，包括 高通量遗传筛选、单细胞表观基因组和转录组技术、计算 方法，临床前癌症模型的发展，以及人类肿瘤数据的测序分析。这些 新的方法，再加上我在分子生物学、显微镜和 生物化学，将使我能够解决表观遗传调控中最紧迫和最具挑战性的问题 今天的癌症生物学。该奖项将允许追寻上述问题并获得经验，以便 成为我自己的癌症小组的领导者，也是表观遗传学领域的领导者。

Project Summary/Abstract The chromatin landscape governs basic cellular functions that are altered in cancer, including genomic architecture, gene expression, and developmental pathways. Interestingly, epigenetic dysregulation of chromatin is an emerging hallmark of cancer. These epigenetic changes in turn render cancer cells highly reliant on the chromatin machinery to maintain their malignant state, thus creating opportunities for therapeutic intervention by targeting chromatin modifiers. Driven by the desire to understand the basic mechanistic underpinnings of epigenetic regulation, it is my goal to address pressing questions in molecular biology and contribute to the advancement of cancer prevention and treatment. Histone post-translational modifications (PTMs) are central regulators of chromatin processes, and genes encoding chromatin factors are highly mutated in a range of cancers. This project seeks to understand the role of the Polycomb Repressive Complex 2 (PRC2) in cancer development. PRC2 is a major epigenetic machinery responsible for the maintenance of heterochromatin and catalysis of histone H3 lysine 27 methylation. The F99 phase of this proposal is focused on investigating the regulation of PRC2 enzymatic activity by the highly conserved SANT1-like binding (SBD) domain of its EZH2 subunit. Despite the broad understanding of PRC2 function and regulation, the molecular role of the N-terminal SBD of EZH2 is unknown. The preliminary data reveals novel mechanistic insight about this domain in the catalysis of H3K27 methylation. Surprisingly, partial deletion of the SBD domain in EZH2 (SBD-EZH2) leads to a global loss of repressive H3K27me2 and H3K27me3, phenocopying the complete loss of EZH2 at the epigenomic level. In the remainder of the dissertation work, my main research efforts will be directed toward delineating the regulatory significance of the EZH2-SBD domain in the allosteric activation of PRC2 enzymatic activity, as well as determining a potential inhibitory mechanism for lymphoma patients harboring EZH2 gain-of-function mutations. The K00 phase of this project will be focused on studying the role of PRC2 loss in the development of the highly aggressive malignant peripheral nerve sheath tumors (MPNSTs). Interestingly, the loss of PRC2 components is involved in the malignant formation of sporadic and radiotherapy-associated MPNSTs. Thus, to further understand the molecular mechanisms of these tumors, I plan to expand my technical expertise to include high-throughput genetic screening, single-cell epigenomic and transcriptomic techniques, computational approaches, development of preclinical cancer models, and sequencing analysis of human tumor data. These new approaches, coupled with my already strong background in molecular biology, microscopy, and biochemistry, will allow me to address the most pressing and challenging issues in epigenetic regulation and cancer biology today. This award will allow to pursue the above questions and and gain experience in order to become a leader of my own cancer-focused group and a leader in the field of epigenetics.