Posttranslational Regulation of FOXA1 in Breast Cancer

FOXA1 在乳腺癌中的翻译后调控

基本信息

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
项目类别：
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

项目摘要

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.

项目概要乳腺癌是女性癌症死亡的第二大原因，占所有乳腺癌死亡人数的近 75% 尽管治疗取得了成功，但肿瘤在诊断时仍表达雌激素受体α（ER）。针对 ER 功能而设计的内分泌疗法，约 30-40% 的肿瘤对内分泌产生耐药性治疗，无论是通过从头还是获得性耐药，并且仍然保留 ER 的表达。研究 FOXA1 的调控，FOXA1 是一种先驱转录因子，可使 ER 与染色质结合，其理论上的抑制将规避已知的乳腺癌内分泌治疗耐药机制。 FOXA1 负责基因组中几乎所有的 ER 结合事件，并且其上调与之相关然而，关于如何增强子重编程的信息很少。 FOXA1 本身受到调节，以及癌细胞如何重新利用其开创性活动来驱动肿瘤发生。为此，我们的实验室一直在研究内分泌系统和免疫系统之间的串扰。我们发现 FOXA1 响应促炎细胞因子，被驱动至非乳腺癌。跨基因组的规范位点，以促进雌激素配体 ER 染色质的可及性。在基因组的压缩/隐藏区域中发现了形成的增强子，并促进了同时，我们发现 FOXA1 可以预测患者的不良临床结果。在两个进化上保守的位置对促炎细胞因子进行翻译后修饰（PTM）尚未显示 FOXA1 响应外部刺激的翻译后修饰。之前并提出了 FOXA1 调节和功能的重要机制。该项目的总体目标是确定允许促炎症信号改变的分子事件通过调节 FOXA1 功能的内分泌信号传导以及这种串扰的生物学后果。我们遭受雌激素和 TNFα 指导的 FOXA1 PTM 决定结合位点选择，驱动 ERα 跨基因组的非规范增强子，导致肿瘤发生的表达程序为了系统地检验这一假设，我们将使用一套综合的分子、基因组和方法。蛋白质组学方法：（目标 1）定义 FOXA1 PTM 对其先驱功能和染色质的作用占用率，（目标 2）识别 FOXA1 PTM 的作者和读者，以及（目标 3）了解炎症- 我们将在乳腺癌细胞中进行这些实验。细胞系、ER+ 患者来源的异种移植物 (PDX) 以及从患者肿瘤分离的 ER+ 成熟管腔细胞中。激素受体信号转导对 FOXA1 的依赖使其成为一个有吸引力的治疗靶点。目前尚无已知的 FOXA1 抑制剂及其蛋白质结构使其难以靶向治疗，我们的了解基本分子机制的能力与我们更好地发展的能力直接相关定义 FOXA1 的调节方式成为这一努力的关键。