Posttranslational Regulation of FOXA1 in Breast Cancer

FOXA1 在乳腺癌中的翻译后调控

• 批准号: 10504308
• 负责人: Hector Luis Franco
• 金额: $ 47.89万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2027-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10504308
• 关键词: ATAC-seq; Acetylation; Affect; Amino Acids; Antibodies; Automobile Driving; Binding; Binding Sites; Biological; Biophysics; Biotin; Breast Cancer cell line; Cancer Biology; Cancer Etiology; Cell Line; Cells; ChIP-seq; Chromatin; Clinical; Clustered Regularly Interspaced Short Palindromic Repeats; Coupled; Custom; DNA Binding; Data; Dependence; Developmental Process; Diagnosis; Endocrine; Endocrine system; Enhancers; Epigenetic Process; Epithelial Cells; Estrogen Receptor alpha; Estrogen Receptors; Estrogen receptor positive; Estrogens; Event; Gene Expression; Genes; Genetic; Genetic Screening; Genome; Genomics; Goals; Hormone Receptor; Human; Immune system; Immunoprecipitation; Inflammation; Inflammatory; Knock-in; Label; Ligands; Ligase; Link; Logic; Lysine; Malignant Neoplasms; Mammaplasty; Mammary Neoplasms; Mass Spectrum Analysis; Measures; Mediating; Molecular; Normal Cell; Nuclear Receptors; Nucleosomes; Outcome; Patients; Physiological Processes; Play; Post-Translational Protein Processing; Post-Translational Regulation; Primary Neoplasm; Proteins; Proteomics; Reader; Reagent; Receptor Signaling; Regulation; Resistance; Role; Signal Transduction; Site; Specimen; Stimulus; Structure; TNF gene; Tamoxifen; Techniques; Testing; Therapeutic; Therapeutic Intervention; Time; Tissues; Transferase; Up-Regulation; Woman; base; breast tumorigenesis; cancer cell; cytokine; experimental study; global run on sequencing; hormone therapy; inhibitor; malignant breast neoplasm; mortality; mouse model; mutant; novel; patient derived xenograft model; prevent; programs; protein structure; receptor binding; recruit; response; single-cell RNA sequencing; success; targeted treatment; therapeutic target; therapy design; transcription factor; transcriptome sequencing; tumor; tumorigenesis

Project Summary Breast cancer is the second leading cause of cancer mortality in women and nearly 75% of all breast tumors express estrogen receptor alpha (ER) at the time of diagnosis. Despite the therapeutic successes of endocrine therapies designed to target ER function, about 30-40% of tumors become resistant to endocrine therapy, either through de novo or acquired resistance, and still retain the expression of ER. Herein we propose to study the regulation of FOXA1, a pioneer transcription factor that enables ER binding to chromatin, whose theoretical inhibition would circumvent known mechanisms of endocrine therapy resistance. In breast cancer, FOXA1 is responsible for almost all of the ER binding events in the genome and its upregulation is associated with enhancer reprograming in endocrine resistance. However, there is a paucity of information about how FOXA1 itself is regulated and how cancer cells repurpose its pioneering activities to drive oncogenesis. To this end, our lab has been studying the crosstalk between the endocrine and immune systems in breast cancer. We have discovered that FOXA1, in response to the proinflammatory cytokines, is driven to non- canonical sites across the genome to promote chromatin accessibility for estrogen-liganded ER. These newly formed enhancers were found in compacted/latent regions of the genome and promoted the expression of a novel gene set that was predictive of poor clinical outcomes in patients. Concurrently, we discovered that FOXA1 is post-translationally modified (PTM) in response to proinflammatory cytokines at two evolutionarily conserved amino acids. The post-translational modification of FOXA1 in response to external stimuli has not been shown before and suggests an important mechanism that underlies FOXA1 regulation and function. Therefore, the overall goal of this project is to determine the molecular events that allow proinflammatory signaling to alter endocrine signaling through modulation of FOXA1 function and the biological consequences of this crosstalk. We hypothesize that estrogen- and TNFα-directed PTMs of FOXA1 dictate binding site selection, driving ERα to non-canonical enhancers across the genome, leading to expression programs that underlie the tumorigenesis of breast cancer. To systematically test this hypothesis, will use an integrated set of molecular, genomic, and proteomic approaches to: (Aim 1) define the role of FOXA1 PTMs on its pioneering function and chromatin occupancy, (Aim 2) identify the writers and readers of FOXA1 PTMs, and (Aim 3) understand inflammation- based modulation of FOXA1 independent of PTMs. We will perform these experiments in breast cancer cell lines, ER+ patient-derived xenografts (PDX), and in ER+ mature luminal cells isolated from patient tumors. The dependence on FOXA1 for hormone receptor signaling makes it an attractive therapeutic target. While there are currently no known inhibitors of FOXA1 and its protein structure makes it difficult to target therapeutically, our ability to understand basic molecular mechanisms is directly correlated with our ability to develop better therapeutic interventions. Defining how FOXA1 is regulated becomes key to this endeavor.

项目摘要 乳腺癌是女性癌症死亡率的第二大原因，几乎所有乳腺癌的近75％ 肿瘤在诊断时表达雌激素受体α（ER）。尽管取得了治疗的成功 旨在靶向ER功能的内分泌疗法，大约30-40％的肿瘤对内分泌具有抗性 通过从头开始或获得抗性，并且仍然保留ER的表达。我们在此提出 研究FOXA1的调节，FOXA1是一​​种先锋转录因子，使ER与染色质结合，谁 理论抑制作用将规避内分泌疗法抗性的已知机制。在乳腺癌中， FOXA1几乎负责基因组中的所有ER结合事件，其上调与 具有增强子在内分泌耐药性中重编程。但是，关于如何 FOXA1本身受到调节，以及癌细胞如何重新利用其开拓性活动以驱动肿瘤发生。 为此，我们的实验室一直在研究内分泌和免疫系统之间的串扰 乳腺癌。我们发现，FOXA1响应促炎细胞因子，被驱动到非 - 整个基因组的规范部位，以促进雌激素辅助ER的染色质可及性。这些新 在基因组的紧凑/潜在区域中发现了形成的增强子，并促进了A的表达 新型基因集可以预测患者的临床结果不佳。同时，我们发现Foxa1 是在两种进化保守的促炎细胞因子的响应后翻译后修饰（PTM） 氨基酸。尚未显示FOXA1对外部刺激的翻译后修饰 以前并提出了一种基于FOXA1调节和功能的重要机制。因此， 该项目的总体目标是确定允许促炎信号传导改变的分子事件 内分泌信号通过调节FOXA1功能和该串扰的生物学后果。 我们假设FOXA1的雌激素和TNFα指导的PTM决定结合位点的选择，驱动ERα 到整个基因组的非典型增强子，导致表达程序是肿瘤发生的基础的 乳腺癌。为了系统地检验这一假设，将使用一组集成的分子，基因组和 蛋白质组学方法：（目标1）定义FOXA1 PTM在其开创性功能和染色质中的作用 占用率，（目标2）确定FOXA1 PTM的作家和读者，（目标3）了解炎症 - 基于FOXA1独立于PTM的调制。我们将在乳腺癌细胞中进行这些实验 线，ER+患者衍生的Xenographictic（PDX），以及从患者肿瘤中分离出的ER+成熟的腔细胞。这 对马酮受体信号传导对FOXA1的依赖使其成为有吸引力的治疗靶点。而有 目前尚无FOXA1及其蛋白质结构的已知抑制剂，因此难以靶向治疗，我们 理解基本分子机制的能力与我们发展更好的能力直接相关 治疗干预措施。定义FOXA1的调节成为这项努力的关键。