Estrogen receptor fusions genes as drivers of endocrine resistance in breast cancer

雌激素受体融合基因作为乳腺癌内分泌抵抗的驱动因素

基本信息

批准号：
10605355
负责人：
Adrian V Lee
金额：
$ 56.76万
依托单位：
UNIVERSITY OF PITTSBURGH AT PITTSBURGH
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-04-01 至 2026-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10605355
关键词：
Adopted Amino Acids Antiestrogen Therapy Base Pairing Binding Biological Assay Biology Biopsy Breast Cancer Model Breast Cancer cell line C-terminal Cell Line Cell model Cells Clinical Code Collection DNA Binding Data Detection Development Disease Drug Modelings Drug resistance ESR1 gene Endocrine Engineering Estrogen Antagonists Estrogen Receptors Estrogen Therapy Estrogen receptor positive Estrogens Evolution Exons Gene Expression Gene Fusion Gene Rearrangement Genes Genetic Transcription Genomics Goals Histologic Hormones Hyperactivity International Introns Ligand Binding Ligands MDA MB 435 Mediator Messenger RNA Metastatic breast cancer Missense Mutation Modeling Molecular Molecular Conformation Monitor Mutation N-terminal NF-kappa B Organoids Pathway interactions Patients Plasma Point Mutation Prevalence Prevention Promoter Regions Proteins Recurrence Reporting Resistance Role Solid Neoplasm Structural Biologist Structure Testing Therapeutic Intervention Transactivation Translating Xenograft procedure advanced breast cancer advanced disease biophysical techniques clinically relevant cohort fusion gene gain of function genome sequencing genomic data genomic locus hormone therapy in vivo insight malignant breast neoplasm mortality multidisciplinary novel novel therapeutics patient derived xenograft model promoter response tumor tumor DNA whole genome

项目摘要

Anti-estrogen therapy is key to the prevention and treatment of estrogen receptor (ER, ESR1) positive breast cancer, but therapy resistance occurs in up to a half of cases resulting in incurable advanced disease. We recently reported recurrent ESR1 fusions in advanced endocrine-resistant breast cancers, with loss of ligand binding representing a canonical model of drug resistance. Intriguingly, cases with ESR1 fusions co-occurred with ESR1 base-pair mutations, likely pointing towards convergent evolution under prolonged anti-estrogen therapy. Evidence from our group and others suggest that ESR1 fusions are found in ~10-20% of advanced breast cancers, however, many ESR1 fusions harbor different 3’ partner genes, making detection challenging. To determine prevalence, we will comprehensively re-analyze the ESR1 genomic locus in data from metastatic breast cancers. Further, we have developed and optimized a target capture sequencing assay capable of comprehensively detecting ESR1 fusions in both tumor biopsies and ctDNA. We have identified endogenous ESR1 fusions that are expressed in two patient derived xenografts (PDX) (ESR1-LPP and ESR1-NFkB) and in an ER-positive breast cancer cell line MDA-MB-435 (ESR1-SYNE1). We will express ESR1 fusions in recently generated patient-derived organoids (PDO) which show ER expression and response to estrogen that is equal or greater than traditional cell lines. Intriguingly, different ESR1 fusions show stark differences in activity, implicating a role for the 3’ gene partner in modulating activity of the ESR1 N terminal domain (NTD). The NTD is an intrinsically disordered protein within the transactivation domain, and using a novel integrative-biophysics approach, we recently reported that while it is mostly disordered, it can adopt an unexpectedly compact conformation which in turn directs interaction with coregulators. In this proposal we seek to test the hypothesis that ESR1 fusions are key mediators of endocrine-resistance and breast cancer mortality. We will employ EnRich to determine the prevalence of ESR1 fusions (and point mutations) in national and international clinical cohorts of advanced endocrine resistant breast cancer and monitor when they arise during therapy using longitudinal collection of plasma and ctDNA analyses. We will use patient-derived organoid models of breast cancer to compare and contrast the activity and function of ESR1 fusions and point mutations relative to wild- type ER and translate this into in vivo patient derived organoid xenograft (PDOX) and (PDX) models to assess endocrine resistance. We will study mechanism of action, including the effects on DNA binding and transcriptional activity, and the role of the 3’ partner gene in any gain of function activities. Finally, we will examine the structure-function of ESR1 fusions focusing on the NTD and determining the altered structure in the context of the fusion partner before assessing the function of specific NTD amino acids and how they change structure and subsequent target gene expression. We believe our multi-disciplinary studies will provide mechanistic insight to aid in the development of new therapies against breast cancers with ESR1 fusions.

抗雌激素治疗是防治雌激素受体（ER、ESR1）阳性乳腺的关键癌症，但多达一半的病例会出现治疗抵抗，导致无法治愈的晚期疾病。最近报道了晚期内分泌耐药乳腺癌中反复发生 ESR1 融合，并伴有配体丢失有趣的是，ESR1 融合的病例同时发生。具有 ESR1 碱基对突变，可能指向长期抗雌激素作用下的趋同进化我们小组和其他人的证据表明，约 10-20% 的晚期患者存在 ESR1 融合。然而，在乳腺癌中，许多 ESR1 融合体含有不同的 3' 伙伴基因，这使得检测具有挑战性。为了确定患病率，我们将全面重新分析转移性乳腺癌数据中的 ESR1 基因组位点。此外，我们还开发并优化了一种能够用于乳腺癌的靶标捕获测序分析。全面检测肿瘤活检和 ctDNA 中的 ESR1 融合，我们已鉴定出内源性。 ESR1 融合在两个患者来源的异种移植物 (PDX)（ESR1-LPP 和 ESR1-NFkB）和 ER 阳性乳腺癌细胞系 MDA-MB-435 (ESR1-SYNE1) 我们将在最近表达 ESR1 融合体。生成了患者来源的类器官 (PDO)，其显示 ER 表达和对雌激素的反应相同或更有趣的是，不同的 ESR1 融合体在活性上表现出明显的差异。暗示 3' 基因伴侣在调节 ESR1 N 末端结构域 (NTD) 活性中的作用。是反式激活域内本质上无序的蛋白质，并使用新颖的综合生物物理学方法，我们最近报道说，虽然它大多是无序的，但它可以采用意想不到的紧凑构象反过来又指导与核心调节器的相互作用。在这个提议中，我们试图检验这个假设。 ESR1 融合是内分泌抵抗和乳腺癌死亡率的关键介质。 EnRich 确定国内和国际临床中 ESR1 融合（和点突变）的患病率晚期内分泌抵抗性乳腺癌队列并在治疗期间监测它们何时出现我们将使用患者来源的乳腺类器官模型进行纵向收集血浆和 ctDNA 分析。癌症，比较和对比 ESR1 融合和点突变相对于野生型的活性和功能类型 ER 并将其转化为体内患者衍生的类器官异种移植 (PDOX) 和 (PDX) 模型以评估我们将研究作用机制，包括对 DNA 结合的影响和转录活性，以及 3' 伙伴基因在任何功能活动获得中的作用。检查 ESR1 融合的结构功能，重点关注 NTD 并确定改变的结构在评估特定 NTD 氨基酸的功能以及它们如何发挥作用之前，先了解融合伙伴的背景我们相信我们的多学科研究将提供改变结构和随后的目标基因表达。机制洞察有助于开发 ESR1 融合乳腺癌新疗法。