Elucidating the role of the SWI/SNF complex in mediating hormone therapy resistance in breast cancer

阐明 SWI/SNF 复合物在介导乳腺癌激素治疗耐药中的作用

• 批准号: 10410445
• 负责人: Eneda Toska
• 金额: $ 18.84万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-01 至 2023-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10410445
• 关键词: 3-Dimensional; ARID1A gene; ATAC-seq; Affect; Alleles; Aromatase Inhibitors; Basal Cell; Binding; Binding Sites; Biological Assay; Breast; Breast Cancer Cell; Breast Cancer cell line; Candidate Disease Gene; Cell Line; Cell Lineage; Cells; Chromatin; Chromatin Remodeling Factor; Clinical; Clustered Regularly Interspaced Short Palindromic Repeats; Complex; Data; Disease; Endocrine; Epigenetic Process; Estrogen Receptors; Estrogen receptor positive; Estrogens; Fulvestrant; Gene Expression; Genes; Genetic Transcription; Growth; Hormonal; Human; In Vitro; Individual; Knock-out; Knockout Mice; Laboratory Study; Light; Loss of Heterozygosity; MCF7 cell; Mammary Neoplasms; Mammary gland; Mediating; Mediator of activation protein; Metastatic breast cancer; Modeling; Mus; Mutate; Mutation; Neoplasm Metastasis; Normal Cell; Organoids; Patients; Phenotype; Play; Pre-Clinical Model; Publishing; Receptor Cell; Refractory; Resistance; Role; SMARCB1 gene; SMARCE1 gene; SWI/SNF Family Complex; Sampling; Series; Testing; Transcriptional Regulation; Transgenic Mice; behavior change; chromatin remodeling; cohort; epigenome; experimental study; genome analysis; genome-wide; hormone therapy; in vivo; inhibitor therapy; loss of function; malignant breast neoplasm; mammary; mammary epithelium; mammary gland development; mouse model; mutant; neoplastic cell; patient derived xenograft model; patient population; programs; recruit; resistance mechanism; response; therapy resistant; transcription factor; transcriptome sequencing; transdifferentiation; tumor

PROJECT SUMMARY Approximately 70% of breast cancers express estrogen receptor (ER) and are treated typically with endocrine therapy. Despite the clinical benefit obtained from several types of endocrine therapies, emergence of resistance to these agents eventually develops in all patients with metastatic disease. We have sequenced 2,752 ER-positive breast cancer samples for which detailed clinical information on response to endocrine therapy is available. These analyses have also shown a correlation between emergence of endocrine therapy resistance and the presence of inactivating mutations in the chromatin remodeler ARID1A. In parallel, we have performed an epigenome-wide CRISPR knockout screen on MCF7 ER-positive breast cancer cells and have identified ARID1A to be the top candidate gene whose loss results in resistance to the Selective ER Degrader (SERD) fulvestrant followed by the loss of additional SWI/SNF subunits, namely SMARCB1, SMARCE1. When we interrogated our internal patient cohort, we found that ARID1A loss is enriched in the metastatic setting and correlates with resistance to SERDs (e.g. fulvestrant). These findings indicate an important role for ARID1A in mediating resistance to endocrine therapy. Mechanistically, our published and preliminary data demonstrate that loss of ARID1A leads to widespread changes in the chromatin landscape of breast cancer cells, resulting in loss of motifs for TFs involved in ER-dependent transcription and luminal (ER+) cell identity. This was accompanied by increase expression of basal (ER-) markers in cell line models and patient samples harboring ARID1A inactivating mutations. In this proposal, we will seek to define the mechanistic basis by which ARID1A acts as a mediator of resistance to endocrine therapy in breast cancer cell lines, patient-derived xenografts and samples from patients with ARID1A mutant breast cancers, and to determine how ARID1A loss results in trans-differentiation from a luminal to a basal program in breast cancers and normal cells. We will perform RNA-seq utilizing samples from patients with hormone therapy-refractory breast cancers that are either wild-type or null for ARID1A. We will then investigate the impact that the knockout of ARID1A has on chromatin recruitment of the SWI/SNF complex and on the binding of the SWI/SNF complex at dominant transcription factors that regulate gene expression programs critical for the cellular differentiation state in breast cancer. Finally, we will study the effects of Arid1a loss in mammary-gland morphogenesis utilizing a mammary epithelium-specific conditional Arid1a null mouse model we have developed and normal mammary and breast cancer 3D organoids. Our results will shed light on the role of ARID1A in determining cell fate/lineage and how ARID1A and the SWI/SNF complex plays a causative role in limiting the sensitivity to endocrine therapy.

项目摘要 大约70％的乳腺癌表达雌激素受体（ER），通常用内分泌治疗 治疗。尽管从几种类型的内分泌疗法中获得了临床益处，但出现 所有转移性疾病患者的抗性最终会发展出来。我们已经测序了 2,752 ER阳性乳腺癌样品，以详细介绍有关内分泌反应的临床信息 可以接受治疗。这些分析也显示了内分泌治疗的出现之间的相关性 电阻和在染色质重塑ARID1A中灭活突变的存在。并行，我们 在MCF7 ER阳性乳腺癌细胞和 已经确定ARID1A是顶级候选基因，其损失导致对选择性ER的抗性 DEGRADER（SERD）FULVESTRANT，然后丢失其他SWI/SNF亚基，即Smarcb1， Smarce1。当我们询问内部患者队列时，我们发现ARID1A损失富含 转移设置并与对SERDS的抗性（例如芬维斯特）相关。这些发现表明 ARID1A在介导对内分泌疗法的抗性中的重要作用。从机械上讲，我们发表的 初步数据表明，ARID1A的丢失会导致染色质景观的广泛变化 乳腺癌细胞，导致参与ER依赖性转录和管腔（ER+）的TF的基序损失（ER+） 细胞身份。这伴随着在细胞系模型中的基础（ER-）标记的表达增加，并且 带有ARID1A灭活突变的患者样品。在此提案中，我们将寻求定义 ARID1A充当乳腺癌细胞内分泌疗法抗性的介体的机理基础 线条，衍生的异种移植物以及来自ARID1A突变乳腺癌患者的样本，以及 确定ARID1A损失如何导致乳腺癌中从腔到基础程序的反差异 和正常细胞。我们将使用来自激素治疗的患者的样品进行RNA-Seq 野生型或无效的ARID1A的乳腺癌。然后，我们将研究 ARID1A的敲除对SWI/SNF复合物的染色质募集和结合 SWI/SNF复合物的主要转录因子，调节基因表达程序对 乳腺癌中的细胞分化状态。最后，我们将研究ARID1A损失对乳腺的影响 使用乳腺上皮特异性条件ARID1A无效小鼠模型的形态发生我们 发达，正常的乳腺癌和乳腺癌3D器官。我们的结果将阐明 ARID1A在确定细胞命运/谱系以及ARID1A和SWI/SNF复合物如何在 限制对内分泌疗法的敏感性。