Elucidating the molecular mechanisms of PRMT5i response and resistance in LUAD and PDAC

项目摘要 蛋白质精氨酸甲基转移酶5（PRMT 5）是甲基转移酶复合物的一部分， 二甲基化精氨酸残基在广泛的蛋白质负责许多生物过程。PRMT5 抑制剂（PRMT 5i）已经被开发并且目前处于临床试验中。然而， PRMT 5i的反应和抗性在很大程度上是未知的。我将阐明PRMT 5i的分子机制 在两种肿瘤类型，肺腺癌（LUAD）和胰腺导管癌中， 腺癌（PDAC）。我们的实验室已经鉴定了多个敏感的亲本（P）LUAD和PDAC系， 产生独立的抗性（R）变体。LUAD的实验表明，R细胞都是通过 单一机制，这是药物诱导的，而不是预先存在的，并反映了基因表达的巨大变化。我 假设这种新的基因表达特征使R细胞能够耐受PRMT 5抑制，并避免 扩散缺陷我们已经确定了一个基因，Stmn 2，作为维持PRMT 5i所必需的。 阻力在目标1中，我将剖析STMN 2如何介导这种效应，并将识别和表征 通过CRISPR/Cas9 KO筛选获得额外的抗性调节剂。我假设收养一个 交替的细胞状态将是肿瘤逃避PRMT 5抑制的常见机制，无论 组织类型。在目标2中，我将通过询问PRMT 5i抗性的机制来测试这一想法。 第二种肿瘤类型PDAC，携带与LUAD细胞相同的K-rasG 12 D和tp 53驱动突变。总体而言， 该项目的结果将提供关键的见解，核心生物过程，使PRMT 5i 敏感性和抗性，并建立这些在不同的，或独特的， 肿瘤类型这将极大地推进对PRMT 5i疗法的机制理解，因为这些药物是 进入诊所。 在这个奖学金，大约70-80%的努力将集中在研究相关的活动， 包括阅读文献，做钳工工作，与我的PI、实验室团队和合作者互动，讨论我的 (and他们的）工作，并在实验室会议上提出。剩下的20-30%的精力将集中在 有助于我职业发展的活动，包括写作、口语和指导。重要的是， 麻省理工学院科赫综合癌症研究所的社区和资源提供了一个 特殊的科学和智力环境，以促进我的科学独立性。

Project Summary Protein arginine methyltransferase 5 (PRMT5) is part of a methyltransferase complex that symmetrically dimethylates arginine residues in a wide range of proteins responsible for many biological processes. PRMT5 inhibitors (PRMT5i) have been developed and are currently in clinical trials. However, the determinants of PRMT5i response and resistance are largely unknown. I will elucidate the molecular mechanisms of PRMT5i response and resistance in two tumor types, lung adenocarcinoma (LUAD) and pancreatic ductal adenocarcinoma (PDAC). Our lab has identified multiple sensitive parental (P) LUAD and PDAC lines and generated independent resistant (R) variants. Experiments in LUAD show that the R cells all arise through a single mechanism, which is drug-induced, not pre-existing, and reflects a dramatic shift in gene expression. I hypothesize that this new gene expression signature enables the R cells to tolerate PRMT5 inhibition and avoid proliferation defects. We have already identified one gene, Stmn2, as being essential to maintain PRMT5i resistance. In Aim 1, I will dissect how STMN2 mediates this effect, and will also identify and characterize additional regulators of resistance through CRISPR/Cas9 KO screens. I hypothesize that adoption of an alternate cell state will be the common mechanism by which tumors escape PRMT5 inhibition, irrespective of their tissue type. In Aim 2, I will test this idea by interrogating the mechanisms of PRMT5i resistance in a second tumor type, PDAC, bearing the same K-rasG12D and tp53 driver mutations as the LUAD cells. Overall, results from this project will provide key insights into the core biological processes that enable PRMT5i sensitivity and resistance, and establish the degree to which these are conserved between, or unique to, different tumor types. This will greatly advance the mechanistic understanding of PRMT5i therapies as these drugs are entering the clinic. While on this fellowship, approximately 70-80% of my effort will be focused on research related activities, including reading literature, doing benchwork, interacting with my PI, lab teams and collaborators to discuss my (and their) work, and presenting in lab meetings. The remaining 20-30% of my effort will be focused on activities that will enable my career development, including writing, oral speaking, and mentoring. Importantly, the community and resources available in the Koch Institute for Integrative Cancer Research at MIT provides an exceptional scientific and intellectual environment to advance my scientific independence.