权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Roles of tGLI1 and microRNA Network in Breast Cancer Brain Metastasis

tGLI1 和 microRNA 网络在乳腺癌脑转移中的作用

基本信息

批准号：
10702139
负责人：
HUI-WEN LO
金额：
$ 41.4万
依托单位：
UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-04-01 至 2025-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10702139
关键词：
Alternative Splicing Astrocytes Brain Breast Cancer Cell Breast Cancer Model Breast cancer metastasis Cancer Biology Cell Line Cessation of life Clinical Data Distant ERBB2 gene Exons Family Fatty acid glycerol esters GLI gene Genes Goals Hand Human In Vitro Injections Laboratories Malignant Neoplasms Mediating Mediator of activation protein Metastatic Neoplasm to Lymph Nodes Metastatic malignant neoplasm to brain MicroRNAs Modeling Molecular Mouse Mammary Tumor Virus Mus Neoplasm Circulating Cells Neoplasm Metastasis Organ Pathway interactions Patients Pattern Play Prognosis Protein Isoforms Proteins Role Route SHH gene Sampling Sampling Studies Signal Transduction Stains TP53 gene Testing Transcription Repressor Transgenic Mice Transgenic Organisms Up-Regulation Validation Xenograft procedure Zinc Fingers angiogenesis autocrine base brain cell cancer cell cytokine exosome gain of function implantation in vivo insight knock-down malignant breast neoplasm malignant phenotype mammary migration monomer mouse model neoplastic cell neurotropic novel nucleocytoplasmic transport overexpression paracrine patient derived xenograft model transcription factor tumor tumor growth

项目摘要

The goal of this proposal is to determine the role of tGLI1 (truncated glioma-associated oncogene homolog 1) in breast cancer brain metastasis (BCBM). Our laboratory discovered tGLI1 as an alternatively spliced GLI1 that lacks entire exon 3 and part of exon 4, but retains the ability to undergo nuclear transport and respond to sonic hedgehog-smoothened signaling. In addition to activating known GLI1 target genes, tGLI1 gains the ability to activate genes not regulated by GLI1, leading to increased migration, invasion and angiogenesis. Whether tGLI1 plays any role in metastasis of any tumor type is unknown. Our mouse studies indicated that tGLI1 promotes breast cancer preferential metastasis to the brain and conversely, tGLI1 knockdown selectively suppressed BCBM. tGLI1 protein is overexpressed in lymph node metastases and BCBM samples. In elucidating how tGLI1 promotes BCBM, we found that exosomes secreted from tGLI1-high cancer cells strongly activated astrocytes, the most abundant brain cells known to promote tumor growth when activated, and that tGLI1-high cancer cells had an increased ability to interact with and activate astrocytes in vitro and in vivo. Since microRNAs can be loaded into exosomes and circulating tumor exosomal miRNAs can prime distant organs for organ-specific metastasis, we conducted an exosomal miRNA microarray followed by validations and found that tGLI1-high cancer cells secreted high levels of exosomal miR-1290 and miR-1246 in vitro and in vivo. Whether miR-1290 and miR-1246 play any role in brain metastasis of any cancer or astrocytes is unknown. We observed that miR-1290/1246 inhibited expression of two transcription repressors (FOXA2 and SOX9), which leads to secretion of ciliary neurotropic factor (CNTF) to activate astrocytes and stimulate cancer cells. We hypothesize that tumoral tGLI1 promotes brain metastasis by priming astrocytes in the metastatic niche, and activated astrocytes in turn facilitate BCBM through secreting CNTF. We further hypothesize that tGLI1-high breast cancer cells prime astrocytes via the novel signaling axis: tumoral tGLI1→exosomal miR-1290/1246┤astrocyte FOXA2/ SOX9┤astrocyte CNTF→astrocyte activation. In Aim 1, we will determine the extent to which tGLI1 promotes BCBM using three mouse models (cell line-derived xenograft, PDX, and transgenic mice), overexpression and knockdown approaches, two inoculation routes (intracardiac and mammary fat pad injections), and human patient samples. In Aim 2, we will examine whether and how tumoral tGLI1 upregulates exosomal miR- 1290/1246 to activate astrocytes in the metastatic niche, and clarify how miR-1290/1246 suppress FOXA2 and SOX9 expression within astrocytes, how FOXA2 and SOX9 repress CNTF expression, and the role of CNTF in astrocyte activation and BCBM progression. In Aim 3, we will examine if miR-1290 and miR-1246 play essential roles in tGLI1-mediated BCBM, identify their downstream targets, and elucidate the roles of intracellular miR- 1290/1246 in BCBM. The project could define tGLI1, miR-1290/1246, and CNTF as novel mediators of BCBM and regulators of astrocytes in the metastatic niche, thus providing novel mechanistic insights into BCBM.

这项研究的目的是确定tGLI 1（截短的胶质瘤相关癌基因同源物1）在胶质瘤中的作用。乳腺癌脑转移（BCBM）。我们的实验室发现tGLI 1是一种选择性剪接的GLI 1，缺乏整个外显子3和部分外显子4，但保留了进行核转运和对声波应答的能力。刺猬式平滑信号除了激活已知的GLI 1靶基因外，tGLI 1还能够激活不受GLI 1调控的基因，导致迁移、侵袭和血管生成增加。是否tGLI 1 在任何肿瘤类型的转移中起任何作用是未知的。我们的小鼠研究表明，tGLI 1促进乳腺癌优先转移到大脑，相反，tGLI 1敲低选择性抑制 BCBM。tGLI 1蛋白在淋巴结转移和BCBM样品中过表达。为了阐明tGLI 1 促进BCBM，我们发现从tGLI 1高的癌细胞分泌的外泌体强烈激活星形胶质细胞，已知最丰富的脑细胞在激活时促进肿瘤生长，而tGLI 1高的癌细胞在体外和体内与星形胶质细胞相互作用并激活星形胶质细胞的能力增加。由于microRNA可以加载到外泌体和循环肿瘤外泌体miRNA可以引发远处器官的器官特异性免疫反应。转移，我们进行了一个外泌体miRNA微阵列，随后进行了验证，发现tGLI 1高表达的癌细胞在体外和体内分泌高水平的外泌体miR-1290和miR-1246。miR-1290是否和miR-1246在任何癌症或星形胶质细胞的脑转移中发挥任何作用是未知的。我们观察到 miR-1290/1246抑制两种转录抑制因子（FOXA 2和SOX 9）的表达，从而导致分泌睫状神经营养因子（CNTF）激活星形胶质细胞和刺激癌细胞。我们假设肿瘤tGLI 1通过在转移灶中引发星形胶质细胞促进脑转移，并且活化星形胶质细胞反过来通过分泌CNTF促进BCBM。我们进一步假设tGLI 1高表达的乳腺癌细胞通过新的信号传导轴启动星形胶质细胞：肿瘤tGLI 1 →外泌体miR-1290/1246 →星形胶质细胞FOXA 2/ SOX 9星形胶质细胞CNTF→星形胶质细胞活化。在目标1中，我们将确定tGLI 1促进使用三种小鼠模型（细胞系来源的异种移植物、PDX和转基因小鼠）、过表达和敲除方法，两种接种途径（心内和乳房脂肪垫注射），以及人患者样本。在目标2中，我们将研究肿瘤tGLI 1是否以及如何上调外泌体miR-11。 miR-1290/1246激活转移性小生境中的星形胶质细胞，并阐明miR-1290/1246如何抑制FOXA 2和 SOX 9在星形胶质细胞中的表达，FOXA 2和SOX 9如何抑制CNTF表达，以及CNTF在星形胶质细胞中的作用。星形胶质细胞活化和BCBM进展。在目标3中，我们将研究miR-1290和miR-1246是否在在tGLI 1介导的BCBM中的作用，确定其下游靶点，并阐明细胞内miR-11的作用。 1290/1246在BCBM。该项目可以将tGLI 1、miR-1290/1246和CNTF定义为BCBM的新介质和星形胶质细胞的调节剂，从而为BCBM提供了新的机制见解。