Mechanism-based strategies to target ER-mutant endocrine resistant breast cancer

针对 ER 突变内分泌耐药乳腺癌的基于机制的策略

• 批准号: 10358631
• 负责人: Steffi Oesterreich
• 金额: $ 38.6万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-04-01 至 2023-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10358631
• 关键词: Address; Adhesions; Advanced Malignant Neoplasm; Antiestrogen Therapy; Biopsy; Breast Cancer Cell; Breast Cancer Patient; Breast Cancer cell line; CRISPR/Cas technology; Cause of Death; Cell Adhesion; Cell Line; Cells; Clinical; DNA; Dimerization; Disease Progression; Disease Resistance; Drug resistance; ESR1 gene; Endocrine; Estrogen Receptor alpha; Estrogen Receptors; Estrogen receptor positive; Estrogens; Exhibits; Fulvestrant; Gene Expression Regulation; Gene Frequency; Genes; Genetic Transcription; Growth; Hormones; Human; In Vitro; Induced Mutation; Knock-in Mouse; Ligand Binding; Ligand Binding Domain; Ligands; MCF7 cell; Malignant Neoplasms; Mammary Neoplasms; Mediating; Metastatic breast cancer; Modeling; Monitor; Mutation; Neoplasm Metastasis; Nucleotides; Oral; Patients; Phenotype; Primary Neoplasm; Receptor Gene; Regulation; Resistance; Resistance development; Role; Route; Selective Estrogen Receptor Modulators; Site; Specimen; Structure; Structure-Activity Relationship; T47D; Tamoxifen; Testing; Transcript; Transcriptional Regulation; advanced breast cancer; base; cancer cell; cell motility; deprivation; gain of function; genome editing; hormone resistance; hormone therapy; in vivo Model; interdisciplinary approach; liquid biopsy; malignant breast neoplasm; mammary; migration; mouse model; mutant; novel; partial response; patient derived xenograft model; receptor; response; therapeutic target; transcriptome; tumor; tumor growth

Project Summary Two thirds of breast tumors express estrogen receptor (ERα), and although many initially respond to endocrine therapy, a large fraction subsequently develop resistance, causing death due to advanced hormone-resistant disease. A number of groups, including ours, have recently documented the occurrence of single nucleotide mutations in the ERα gene (ESR1) in 20-30% of endocrine-resistant metastatic breast cancer. Limited clinical evidence suggests that patients whose tumors have gained ESR1 mutations suffer from shorter survival. ESR1 hotspot mutations cluster in the ligand-binding domain. Analysis of our CRISPR/Cas9 genome edited breast cancer cells with the most common ESR1 mutations (Y537S and D538G) showed ligand-independent transcriptional activity, and partial resistance to selective estrogen receptor modulators (SERMs) and downregulators (SERDs). Mutant ERα also shows regulation of genes not classically regulated by estrogen, with significant differences between D538G and Y537S. Genes uniquely regulated by mutant ERα are involved in motility, migration, and adhesion, and we have identified such gain-of-function phenotypes in the ESR1- mutant cells. We hypothesize that mutations in ESR1 are enriched in endocrine-resistant breast cancer due to ligand-independent activity of mutant ERα, and a unique gain of function regulating motility and adhesion. The altered transcriptional activities of mutant ERα are mediated by reprograming of the ERα cistrome, as a result of altered interaction with coregulators. Finally, we hypothesize that SERDs will be most effective in inhibiting mutant ERα driven tumor growth. To address these hypotheses we will use a multidisciplinary approach including unique in vitro and in vivo models of mutant ERα action, and analysis of clinical specimens. The specific aims are 1) Evaluate how different ESR1 mutations alter its transcriptional activity and function, 2) Characterize the ligand-dependent and drug-resistant activities of mutant ERa, focusing on gain of function activities, and 3) Determine whether the unique transcriptional regulation by mutant ERα is present in advanced endocrine resistant breast cancers, and whether it is critical for progression and metastasis. We expect that our comprehensive structure-function studies of ERα mutations will not only provide basic information regarding hormone resistance, but will highlight novel routes to therapeutic targeting. !

项目摘要 三分之二的乳腺肿瘤表达雌激素受体(ERα)，尽管许多肿瘤最初对内分泌有反应 治疗后，很大一部分人随后会产生耐药性，由于晚期激素耐药性而导致死亡 疾病。包括我们在内的许多研究小组最近都记录了单核苷酸的发生。 20-30%的内分泌耐药转移性乳腺癌中ERα基因突变。有限的临床 有证据表明，肿瘤获得ESR1突变的患者生存时间较短。 ESR1热点突变聚集在配体结合区。我们编辑的CRISPR/Cas9基因组序列分析 具有最常见ESR1突变(Y537S和D538G)的乳腺癌细胞显示非配体依赖性 转录活性和对选择性雌激素受体调节剂(SERM)和 降压调节器(SERD)。突变型ERα还显示了对不受雌激素经典调控的基因的调控， D538G与Y537S有显著差异。涉及由突变型ERα唯一调控的基因 在运动性、迁移性和粘附性方面，我们已经在ESR1中确定了这些功能获得表型。 突变细胞。我们假设ESR1突变在内分泌抵抗型乳腺癌中丰富 由于突变体ERα的不依赖配体的活性，以及调节运动性和 粘附力。突变型ERα转录活性的改变是通过重新编程 ERαCstrome，作为与协调制子相互作用改变的结果。最后，我们假设SERD 将最有效地抑制突变型ERα驱动的肿瘤生长。 为了解决这些假说，我们将使用多学科的方法，包括独特的体外和体内 突变ERα作用模型及临床标本分析。具体目标是：1)如何评估 不同的ESR1突变改变了其转录活性和功能，2)表征了配体依赖 和耐药突变时代的活性，侧重于功能活性的获得，以及3)决定 突变ERα独特的转录调控在晚期内分泌耐药乳腺癌中存在， 以及它是否是进展和转移的关键。 我们预计，我们对ERα突变的全面结构-功能研究不仅将提供基本的 关于激素抵抗的信息，但将突出治疗靶向的新途径。好了！