Epigenetic mechanisms of therapeutic resistance

项目总结/摘要 细胞表型异质性是肿瘤疾病进展的关键机制， 治疗耐药性，但其调节在分子水平上知之甚少。我们发现， 治疗抗性与细胞间转录组异质性水平较高有关， 通过调节表观遗传组蛋白修饰酶的活性来减少这种异质性，例如 KDM 5 B改善了对治疗的反应。我们还确定了对表观遗传药物的获得性耐药性 药物，包括KDM 5和BET布罗莫结构域抑制剂，是由于表观遗传机制，而获得性 内分泌抗性反映了对预先存在的、遗传上不同的细胞亚群的选择。目标 本项目的目的是研究细胞表型异质性的群体动力学， 腔雌激素受体阳性（ER+）和三阴性乳腺癌对癌症治疗的耐药性 （TNBC）。我们的假设是，由表观遗传调节器控制的细胞状态是高度可变和动态的 这是获得性治疗耐药性的基础。我们还假设，通过调节 表观遗传调节因子，并通过确定合成致死性和获得性抗性的机制， 表观遗传剂，我们可以减少转录组异质性和改善治疗反应。来测试我们 假设，我们将描述遗传和表观遗传异质性对获得性耐药性的影响， 内分泌、化疗和表观遗传疗法（目标1）。我们将使用条形码细胞来跟踪种群动态 在获得性抗性的发展过程中，表征表观遗传景观和转录组学 耐药和耐药群体异质性，并建立数学模型的基础上，实验 数据来预测对不同药剂的治疗抗性的演变。另外，为了定义合成致死 我们将利用CRISPR/Cas9技术研究对表观遗传疗法的获得性抗性的相互作用和机制， 在ER+和TNBC细胞系中筛选（目标2）对表观遗传试剂敏感与抗性的细胞系。总体看 该项目将大大提高我们对表型异质性调节的认识，以及这种调节在表型异质性中的作用。 在治疗反应和抵抗中起作用。

Project Summary/Abstract Cellular phenotypic heterogeneity is a key mechanism underlying neoplastic disease progression and therapeutic resistance, yet its regulation is poorly understood at the molecular level. We have found that elevated therapeutic resistance is associated with higher levels of cell-to-cell transcriptomic heterogeneity and that decreasing such heterogeneity by modulating the activity of epigenetic histone-modifying enzymes such as KDM5B improves responses to treatment. We also determined that acquired resistance to epigenetic drug agents, including KDM5 and BET bromodomain inhibitors, is due to epigenetic mechanisms, whereas acquired endocrine resistance reflects a selection for a pre-existing, genetically distinct sub-populations of cells. The goal of this Project is to investigate the population dynamics of cellular phenotypic heterogeneity in response to and resistance to cancer therapies in luminal estrogen receptor positive (ER+) and triple-negative breast cancer (TNBC). Our hypothesis is that cellular states governed by epigenetic regulators are highly variable and dynamic and that this underlies acquired therapeutic resistance. We also hypothesize that by modulating the activity of epigenetic regulators and by identifying mechanisms of synthetic lethality and the acquired resistance to epigenetic agents, we can decrease transcriptomic heterogeneity and improve therapeutic response. To test our hypotheses, we will characterize the impact of genetic and epigenetic heterogeneity on acquired resistance to endocrine, chemo-, and epigenetic therapies (Aim 1). We will use barcoded cells to follow population dynamics during the development of acquired resistance, characterize the epigenetic landscape and transcriptomic heterogeneity of drug-tolerant and -resistant populations, and build mathematical models based on experimental data to predict the evolution of therapeutic resistance to different agents. Additionally, to define synthetic-lethal interactions and mechanism of acquired resistance to epigenetic therapies we will perform CRISPR/Cas9 screens (Aim 2) in ER+ and TNBC cell lines that are sensitive versus resistant to epigenetic agents. Overall, the project will significantly advance our knowledge of the regulation of phenotypic heterogeneity and the role this plays in therapeutic responses and resistance.