Estrogen-Estrogen Receptor axis in non-transformed breast epithelial cells: studies beyond MCF-7

非转化乳腺上皮细胞中的雌激素-雌激素受体轴：MCF-7 以外的研究

基本信息

批准号：
9024970
负责人：
Harikrishna Nakshatri
金额：
$ 7.8万
依托单位：
INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-12-04 至 2017-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9024970
关键词：
Address Age BRCA1 gene Binding Binding Sites Bioinformatics Biological Assay Biology Breast Breast Cancer cell line Breast Epithelial Cells Cancer cell line Cell Fraction Cell Line Cells ChIP-seq Clinical Communities Cyclin D1 DNA Modification Methylases Data Data Set Defect Development Drug Targeting Elements Epithelial Cells Estrogen Antagonists Estrogen Receptor alpha Estrogen Receptors Estrogen Therapy Estrogens Event Gene Expression Gene Expression Profile Gene Targeting Genes Genetic Transcription Genome Genomic Segment Genomics Goals Growth Histone Deacetylase Inhibitor Hormones Human Individual Interphase Cell Knowledge Ligands Light Link Literature MCF7 cell Malignant Neoplasms Mammary gland Menstrual cycle Methods Mus Mutation Normal Cell Nuclear Receptors Oncogenic Pathway interactions Patients Pattern Play Pregnancy Progesterone Proliferating Protein-Serine-Threonine Kinases Proto-Oncogene Proteins c-akt Receptor Signaling Repression Research Resistance Resources Role Signal Pathway Signal Transduction Stem cells Supporting Cell System Telomerase Testing Transforming Growth Factor beta Tumor Suppressor Genes Ubiquitination c-Myc Staining Method cancer cell cell transformation cell type chromatin modification gene repression genome-wide genomic aberrations high risk immortalized cell malignant breast neoplasm mouse model mutant paracrine prevent progenitor prognostic programs public health relevance response tool transcription factor transcriptome transcriptome sequencing tumor

项目摘要

DESCRIPTION (provided by applicant): Estrogen (E2) acting through the nuclear receptor estrogen receptor alpha (ERα) plays a major role in breast cancer. Approximately 70% of breast cancers express ERα and patients with ERα-positive breast cancers receive anti-estrogens. However, resistance to anti-estrogen therapy is a major clinical problem. There are at least two critical unresolved issues in this field: 1) in the normal breast, ERα is expressed in 10-20% of non- dividing cells. These ERα-positive cells support proliferation of ERα-negative cells in response to E2 through paracrine action. In contrast to normal cells, ERα-positive cancer cells themselves proliferate in response to E2. Mechanisms governing switch in this ERα function are largely unknown and is the focus of this proposal; 2) Mechanisms of anti-estrogen resistance. Most of our current knowledge of ERα biology including genome- wide binding pattern (ERα cistrome), the role of pioneer factors/chromatin modifications in guiding ERα cistrome, and E2-regulated gene expression pattern (E2-transcriptome) are from studies using the cancer cell line MCF-7 but not normal/non-transformed cells because it has not been technically possible to culture ERα- expressing non-transformed cells. This limitation has prevented us from understanding the function of ERα in the normal breast and mechanisms that govern cancer-associated shift in ERα function. To address these critical issues, we generated several ERα-positive breast epithelial cell lines by propagating cells from normal breast using recently described epithelial cell-reprogramming assay followed by immortalization using the hTERT. Consistent with the predicted expression pattern of ERα in primary cells, ERα is expressed in the luminal progenitor and mature cell but not in stem cell fraction of these cell lines, which authenticates the relevance of the system. RNA-seq analysis of one of these cell lines showed dominant action of ERα:E2 in repressing gene expression. In contrast, ERα-signaling involved both activation and repression in cancer cells and was well integrated with PI3K-Cyclin D1-cMyc proliferation network as well as an atypical ubiquitination system not seen in normal cells. Using these new resources, we will address the hypothesis that switch in ERα cistrome and E2-transciptome from a repressor mode to a activator mode is a critical early step in ERα- positive breast cancer. The specific aims are to: 1) Define ERα cistrome that is unique to non-transformed breast epithelial cells; 2) Investigate signaling nodes that govern ERα function in non-transformed and transformed breast epithelial cells by integrating ERα cistrome with transcriptome. Impact: To our knowledge, this is the first study to determine ERα function in non-transformed breast epithelial cells. The resources developed will be valuable to the research community to reassess signaling networks associated with ERα-positive breast cancer and anti-estrogen resistance. In particular, signaling defects linked to genomic aberrations uniquely enriched in ERα-positive breast cancers can be investigated and drugs targeting specific aberration can be identified using this resource.

描述（由适用提供）：通过核受体雌激素受体α（ERα）作用的雌激素（E2）在乳腺癌中起主要作用。大约70％的乳腺癌表达ERα，患有ERα阳性乳腺癌的患者接受抗雌激素。然而，抗抗雌激素疗法的耐药性是一个主要的临床问题。在该领域中至少有两个关键的未解决问题：1）在正常乳房中，ERα在10-20％的非分散细胞中表达。这些ERα阳性细胞通过旁分泌作用支持E2的ERα阴细胞的增殖。与正常细胞相反，ERα阳性癌细胞本身会响应E2增殖。该ERα功能中控制开关的机制在很大程度上是未知的，是该提案的重点。 2）抗雌激素抵抗的机制。 Most of our current knowledge of ERα biology including genome- wide binding pattern (ERα cistrome), the role of pioneer factors/chromatin modifications in guiding ERα cistrome, and E2-regulated gene expression pattern (E2-transcriptome) are from studies using the cancer cell line MCF-7 but not normal/non-transformed cells because it has not been technically possible to culture ERα- expressing non-transformed cells.这种局限性使我们无法理解ERα在正常乳房中的功能以及控制癌症相关的ERα功能转移的机制。为了解决这些关键问题，我们使用最近描述的上皮细胞重新编程测定法进行了几种ERα阳性乳房上皮细胞系，然后使用HTERT永生化。与原代细胞中ERα的预测表达模式一致，ERα在腔内祖细胞和成熟细胞中表达，但在这些细胞系的干细胞分数中不表达，这证实了系统的相关性。这些细胞系之一的RNA-seq分析显示ERα：E2在反映基因表达中的主要作用。相比之下，ERα信号涉及癌细胞中的激活和表达，并与PI3K-CYCLIN D1-CMYC增殖网络以及在正常细胞中未见的非典型泛素化系统充分融合。使用这些新资源，我们将解决以下假设：ERαcistrome和E2-transciptome从复制器模式转换为Activater模式是ERα-阳性乳腺癌的重要早期一步。具体目的是：1）定义非转化乳腺上皮细胞独有的ERαcistrome； 2）研究通过将ERαCISTROME与转录组相结合的非转化和转化的乳腺上皮细胞中ERα功能的信号传导节点。影响：据我们所知，这是确定非转化乳腺上皮细胞中ERα功能的第一项研究。开发的资源对于研究界来说是有价值的，可以重新评估与ERα阳性乳腺癌和抗雌激素耐药性相关的信号网络。特别是，可以研究与富集在ERα阳性乳腺癌中的基因组畸变相关的信号缺陷，并且可以使用此资源来鉴定针对特定像差的药物。