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

• 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
• 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

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.

抗雌激素治疗是预防和治疗雌激素受体（ER，ESR1）阳性乳房的关键 癌症，但耐药性发生在多达一半的病例中，导致无法治愈的晚期疾病。我们 最近报道了高级内分泌乳腺癌中的ESR1融合，配体损失 结合代表耐药性的规范模型。有趣的是，具有ESR1融合的病例共发生 随着ESR1碱基对突变，可能指向延长的抗雌激素下的收敛进化 治疗。我们小组和其他人的证据表明，在〜10-20％的晚期中发现了ESR1融合 但是，乳腺癌许多ESR1融合具有不同的3'伴侣基因，从而挑战了挑战。 为了确定患病率，我们将全面重新分析转移性数据中的ESR1基因组基因座 乳腺癌。此外，我们已经开发并优化了能够的目标捕获测序测定法 全面检测肿瘤活检和CTDNA中的ESR1融合。我们已经确定了内源性 ESR1融合在两个患者衍生的Xenographictics（PDX）（ESR1-LPP和ESR1-NFKB）中表达，并在 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 生成的患者衍生的类器官（PDO），表现出ER表达和对雌激素的反应 或大于传统的细胞系。有趣的是，不同的ESR1融合在活动中显示出明显的差异， 暗示3'基因伴侣在调节ESR1 N终端域（NTD）的活性中的作用。 NTD 是反式激活结构域内的本质上无序的蛋白质，并使用新型的综合生物物理学 方法，我们最近报告说，尽管它大多是无序的，但它可能会出乎意料的紧凑 构象反过来又指导与核心节的相互作用。在此提案中，我们试图检验该假设 ESR1融合是内分泌抗性和乳腺癌死亡率的关键介体。我们将雇用 丰富以确定国家和国际临床中ESR1融合（和点突变）的流行率 晚期内分泌乳腺癌的队列并在治疗期间出现时监测 血浆和CTDNA分析的纵向集合。我们将使用患者衍生的乳房的器官模型 癌症以比较和对比ESR1融合的活性和功能以及点突变相对于野生 键入ER并将其转化为体内患者衍生的器官异种移植（PDOX）和（PDX）模型以评估 内分泌抗性。我们将研究作用机理，包括对DNA结合和 转录活性以及3'伴侣基因在任何功能活动中的作用。最后，我们会的 检查关注NTD的ESR1融合的结构功能，并确定改变的结构 在评估特定NTD氨基酸的功能之前，融合合作伙伴的背景以及它们如何 改变结构和随后的靶基因表达。我们相信我们的多学科研究将提供 有助于开发具有ESR1融合的乳腺癌的新疗法的机械洞察力。