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: 10199597
• 负责人: Eneda Toska
• 金额: $ 24.97万
• 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/10199597
• 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; 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.

项目总结 大约70%的乳腺癌表达雌激素受体(ER)，并通常接受内分泌治疗 心理治疗。尽管从几种类型的内分泌治疗中获得了临床益处，但出现了 所有转移性疾病的患者最终都会对这些药物产生抗药性。我们已经测序了 2,752例ER阳性乳腺癌样本的内分泌反应的详细临床信息 治疗是可用的。这些分析还表明，内分泌治疗的出现与 染色质重构体ARID1a的抗药性和存在失活突变。同时，我们 对MCF7 ER阳性的乳腺癌细胞进行了表观基因组范围的CRISPR基因敲除筛查，并 已经确定ARID1A是首选候选基因，其丢失会导致对选择性ER的抗性 降解物(SERD)fulvestrant随后丢失额外的SWI/SNF亚基，即SMARCB1， SMARCE1.当我们询问我们的内部患者队列时，我们发现ARID1a丢失在 转移环境并与对SERDS(如FUVESTRANT)的耐药性相关。这些发现表明 ARID1A在调节内分泌治疗抵抗中的重要作用。从机制上讲，我们出版的和 初步数据表明，ARID1A的丢失导致了核染色质景观的广泛变化 乳腺癌细胞，导致参与ER依赖的转录和腔(ER+)的转录因子基序丢失 手机身份。伴随而来的是基础(ER-)标记在细胞系模型和 患者样本中存在ARID1A失活突变。在这项建议中，我们将寻求界定 ARID1A作为乳腺癌细胞内分泌耐药介质的机制研究 来自ARID1A突变乳腺癌患者的细胞株、患者来源的异种移植物和样本，以及 确定ARID1A缺失如何导致乳腺癌中腔程序向基础程序的转分化 和正常细胞。我们将利用激素治疗难治性患者的样本进行rna-seq。 野生型或ARID1a基因缺失的乳腺癌。然后我们将调查这一事件的影响 敲除ARID1A对SWI/SNF复合体的染色质募集和对 SWI/SNF复合体位于主要的转录因子，调节基因表达程序对 乳腺癌的细胞分化状态。最后，我们将研究ARID1a丢失对乳腺的影响 利用乳腺上皮特异性条件性ARID1A缺失小鼠模型的形态发生 发达的和正常的乳腺和乳腺癌的3D器官。我们的研究结果将有助于阐明 ARID1A在决定细胞命运/谱系中的作用以及ARID1A和SWI/SNF复合体如何在 限制对内分泌治疗的敏感性。