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

• 批准号: 10542805
• 负责人: Lixin Rui
• 金额: $ 34.26万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 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/10542805
• 关键词: Affect; Agammaglobulinaemia tyrosine kinase; Animal Model; B-Cell Antigen Receptor; B-Lymphocytes; Binding Proteins; Bromodomain; Cancer Etiology; Cell Death; Cell Line; Cells; ChIP-seq; Chromatin; Clinical; Clustered Regularly Interspaced Short Palindromic Repeats; 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; Proliferating; 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; activated B cell like; addiction; antitumor effect; 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' s lymphoma; lenalidomide; leukemia; lymph nodes; molecular subtypes; mortality; mouse model; neoplastic cell; novel; novel marker; novel therapeutic intervention; overexpression; patient derived xenograft model; pharmacologic; preclinical study; resistance mechanism; response; small hairpin RNA; synergism; therapeutically effective; transcriptome sequencing; transcriptomics; translational impact; treatment strategy; tumorigenesis

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.

摘要 弥漫性大B细胞淋巴瘤（DLBCL）占新诊断淋巴瘤的30%至40%， 包括两种主要的分子亚型：活化B细胞样（ABC）和生发中心B细胞样（GCB）。ABC DLBCL更具侵袭性，更难治愈。超过50%的ABC DLBCL患者是难治性或 当前一线免疫化疗复发。布鲁顿选择性抑制剂伊曲替尼的临床应用 酪氨酸激酶（BTK）在B细胞受体（BCR）信号通路中的作用，已经达到了 在难治性/复发性ABC DLBCL中为30%-40%。然而，原发性和获得性耐药仍然很重要 并影响超过60%的患者的长期生存。因此，理解和定位 伊替尼耐药机制是未满足的临床需求。BCR和JAK 1/STAT 3信号通路是 对于ABC DLBCL细胞的存活和增殖至关重要。我们发现EGR 1是一个融合的 ABC DLBCL中两种途径的下游靶点，并且ABC DLBCL中EGR 1表达水平升高 与正常人扁桃体和淋巴结相比。我们揭示了EGR 1的新机制， 在治疗侵袭性肿瘤中具有强翻译影响的靶基因的转录激活和抑制 淋巴瘤EGR 1通过p300/H3 K27 ac/BRD 4轴介导转录激活以诱导MYC 表达和激活MYC靶基因。在EGR 1和EGR 2之间观察到细胞生长的协同抑制作用。 shRNA和AZD 5153，一种目前正在临床研究的新型BRD 4抑制剂。另一方面，在一项研究中， EGFR 1介导I型干扰素途径基因的转录抑制，否则I型干扰素途径基因的表达 导致癌细胞死亡。因此，通过shRNA敲低EGFR 1与I型干扰素诱导剂协同作用 来那度胺在体外和异种移植小鼠模型中对ABC DLBCL细胞的生长抑制。使用新 我们证明了EGR 1是最高表达的， 相对于伊匹替尼敏感亲本细胞表达的基因，以及BRD 4和干扰素信号传导的共靶向 在体外和体内抑制伊匹替尼耐药细胞的生长。基于这些发现，中心假设 EGR 1是一种独特的致癌驱动因子，协调多种重要的信号通路， ABC DLBCL患者的治疗脆弱性，尤其是对伊鲁替尼耐药的患者。来测试我们 因此，我们将致力于以下具体目标：（1）阐明EGFR 1在肿瘤发生中的作用;（2） 确立EGR 1在伊鲁替尼耐药性中的作用;和（3）共同靶向EGR 1下游BRD 4和I型 干扰素信号传导以克服DLBCL中的耐药性。剖析转录激活， EGR 1的阻遏模块在DLBCL肿瘤发生和伊鲁替尼耐药中是必不可少的，因为新的 机制的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，包括具有伊鲁替尼耐药性的患者。