Targeting EGR1 signaling pathways in diffuse large B cell lymphoma

靶向弥漫性大 B 细胞淋巴瘤中的 EGR1 信号通路

基本信息

批准号：
10340232
负责人：
Lixin Rui
金额：
$ 34.96万
依托单位：
UNIVERSITY OF WISCONSIN-MADISON
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-12-20 至 2026-11-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10340232
关键词：
Affect Agammaglobulinaemia tyrosine kinase Animal Model B-Cell Activation B-Cell Antigen Receptor B-Lymphocytes Binding Proteins Bromodomain CRISPR/Cas technology Cancer Etiology Cell Death Cell Line Cells ChIP-seq Chromatin Clinical Data Drug Targeting Drug resistance EP300 gene Engineering Gene Expression Gene Expression Regulation Genes Genetic Genetic Transcription Genomics Growth Hematology Histones Human Immuno-Chemotherapy In Vitro Interferon Inducers Interferon Type I Interferons JAK1 gene Leukocytes Lymphocyte Lymphoma Lymphoma cell Malignant Neoplasms Mediating Molecular Multiple Myeloma Newly Diagnosed Oncogenes Oncogenic Pathway interactions Patients Pharmacology Proteins Reader Refractory Relapse Research Resistance Role Signal Pathway Signal Transduction Solid Stat3 Signaling Pathway Structure of germinal center of lymph node Testing Therapeutic Tonsil Transcriptional Activation Tumor Suppressor Proteins United States Up-Regulation Xenograft Model Xenograft procedure acquired drug resistance addiction antitumor effect base cancer cell cell growth clinical investigation design gene repression genetic manipulation genome wide association study in vivo inhibitor insight interest knock-down large cell Diffuse non-Hodgkin&apos s lymphoma lenalidomide leukemia lymph nodes molecular subtypes mortality mouse model neoplastic cell novel novel marker novel therapeutic intervention overexpression patient derived xenograft model preclinical study resistance mechanism response small hairpin RNA therapeutically effective transcriptome sequencing transcriptomics translational impact treatment strategy tumorigenesis

项目摘要

ABSTRACT Diffuse large B cell lymphoma (DLBCL), which represents 30% to 40% of newly diagnosed lymphomas, comprises two main molecular subtypes: activated B cell-like (ABC) and germinal center B cell-like (GCB). ABC DLBCL is more aggressive and less curable. More than 50% of patients with ABC DLBCL are refractory to or relapse from current frontline immunochemotherapy. Clinical use of ibrutinib, a selective inhibitor for Bruton tyrosine kinase (BTK) in the B cell receptor (BCR) signaling pathway, has achieved an initial response rate of 30%-40% in refractory/relapsed ABC DLBCL. Primary and acquired drug resistance, however, are still significant and impact the long-term survival of more than 60% of these patients. Therefore, understanding and targeting ibrutinib resistance mechanisms is an unmet clinical need. The BCR and JAK1/STAT3 signaling pathways are essential for the survival and proliferation of ABC DLBCL cells. We discovered that EGR1 is a converged downstream target of both pathways in ABC DLBCL and the level of EGR1 expression is elevated in ABC DLBCL compared with normal human tonsils and lymph nodes. We revealed novel mechanisms of EGR1 in transcriptional activation and repression of target genes with strong translational impact in treating aggressive lymphoma. EGR1 mediates transcriptional activation through the p300/H3K27ac/BRD4 axis to induce MYC expression and activate MYC target genes. Synergistic inhibition of cell growth was observed between EGR1 shRNA and AZD5153, a novel BRD4 inhibitor that is currently under clinical investigation. On the other hand, EGR1 mediates transcriptional repression of the type I interferon pathway genes, expression of which otherwise causes cancer cell death. Consistently, EGR1 knockdown by shRNA synergizes with the type I interferon inducer lenalidomide in growth inhibition of ABC DLBCL cells in vitro and in a xenograft mouse model. Using newly derived, ibrutinib-resistant ABC DLBCL cell lines, we demonstrated that EGR1 is among the most highly expressed genes relative to ibrutinib-sensitive parental cells, and co-targeting of BRD4 and interferon signaling inhibits growth of ibrutinib-resistant cells in vitro and in vivo. Based on these discoveries, the central hypothesis is that EGR1 is a unique oncogenic driver orchestrating multiple important signaling pathways and represents therapeutic vulnerability in patients with ABC DLBCL, especially for those with ibrutinib resistance. To test our hypothesis, we will pursue the following specific aims: (1) Elucidate effects of EGR1 on oncogenesis; (2) Establish the role of EGR1 in ibrutinib resistance; and (3) Co-target EGR1 downstream BRD4 and type I interferon signaling to overcome drug resistance in DLBCL. Dissecting the transcriptional activation and repression modules of EGR1 in DLBCL tumorigenesis and ibrutinib resistance is essential because the novel mechanistic insights will provide a molecular basis for developing the most effective therapeutic strategy for treatment of DLBCL patients, including those with ibrutinib resistance.

抽象的弥漫性大 B 细胞淋巴瘤 (DLBCL)，占新诊断淋巴瘤的 30% 至 40%，包括两种主要分子亚型：活化 B 细胞样 (ABC) 和生发中心 B 细胞样 (GCB)。 ABC DLBCL 更具侵袭性且不易治愈。超过 50% 的 ABC DLBCL 患者难治或当前一线免疫化疗复发。布鲁顿选择性抑制剂依鲁替尼的临床应用 B 细胞受体 (BCR) 信号通路中的酪氨酸激酶 (BTK) 已达到难治性/复发性 ABC DLBCL 占 30%-40%。然而，原发性和获得性耐药性仍然很重要并影响超过 60% 的患者的长期生存。因此，了解并瞄准依鲁替尼耐药机制是一个未满足的临床需求。 BCR 和 JAK1/STAT3 信号通路是对于 ABC DLBCL 细胞的生存和增殖至关重要。我们发现EGR1是一个融合的 ABC DLBCL 中两条通路的下游靶标，并且 ABC DLBCL 中 EGR1 表达水平升高与正常人扁桃体和淋巴结相比。我们揭示了 EGR1 的新机制靶基因的转录激活和抑制对治疗侵袭性具有强烈的翻译影响淋巴瘤。 EGR1通过p300/H3K27ac/BRD4轴介导转录激活诱导MYC 表达并激活 MYC 靶基因。观察到 EGR1 之间对细胞生长的协同抑制 shRNA 和 AZD5153，一种目前正在临床研究的新型 BRD4 抑制剂。另一方面， EGR1介导I型干扰素途径基因的转录抑制，否则该基因的表达导致癌细胞死亡。一致地，shRNA 敲低 EGR1 与 I 型干扰素诱导剂具有协同作用来那度胺在体外和异种移植小鼠模型中抑制 ABC DLBCL 细胞生长的作用。新使用衍生的、依鲁替尼耐药的 ABC DLBCL 细胞系中，我们证明 EGR1 是最高度耐药的细胞系之一。与依鲁替尼敏感亲本细胞相关的表达基因，以及 BRD4 和干扰素信号传导的共同靶向在体外和体内抑制依鲁替尼耐药细胞的生长。基于这些发现，中心假设 EGR1 是一种独特的致癌驱动因素，协调多个重要的信号通路并代表 ABC DLBCL 患者的治疗脆弱性，尤其是对依鲁替尼耐药的患者。来测试我们的假设，我们将追求以下具体目标：（1）阐明EGR1对肿瘤发生的影响； (2) 确立EGR1在依鲁替尼耐药中的作用； (3) 共同靶向 EGR1 下游 BRD4 和 I 型干扰素信号传导克服 DLBCL 的耐药性。剖析转录激活和 EGR1 的抑制模块在 DLBCL 肿瘤发生和依鲁替尼耐药中至关重要，因为新的机制见解将为开发最有效的治疗策略提供分子基础治疗 DLBCL 患者，包括对依鲁替尼耐药的患者。