KDR/VEGFR2 regulation of HTLV-1 oncogenesis and viral gene expression

KDR/VEGFR2 对 HTLV-1 肿瘤发生和病毒基因表达的调节

基本信息

批准号：
10353507
负责人：
EDWARD W HARHAJ
金额：
$ 24.35万
依托单位：
PENNSYLVANIA STATE UNIV HERSHEY MED CTR
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：
2022-04-18 至 2024-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10353507
关键词：
Adult T-Cell Leukemia/Lymphoma American Antiviral Agents Apoptosis Apoptotic Automobile Driving Biological Assay CREB1 gene Cell Cycle Cell Death Cell Line Cell Survival Cells Chronic Clinic Clinical Clone Cells Complex Critical Pathways Cycloheximide Data Deltaretrovirus Development Disease EP300 gene Etiology Family Foundations Gene Expression Genes Guide RNA Heat-Shock Proteins 90 Human T-lymphotropic virus 1 Immune response Individual Infection Inflammatory Integration Host Factors Investigation KDR gene Knock-out Lead Ligands Link Long Terminal Repeats Lymphoma cell MAP Kinase Signaling Pathways Malignant Neoplasms Mediating Modeling Molecular Chaperones Mutation NF-kappa B Neoplasms North America Oncogenes Oncogenic Oncoproteins Pathogenesis Pathway interactions Patients Persons Phosphorylation Phosphotransferases Play Post-Translational Protein Processing Protein Tyrosine Kinase Proteins Proto-Oncogene Proteins c-akt Proviruses Receptor Protein-Tyrosine Kinases Regulation Retroviridae Role Signal Pathway Signal Transduction Solid Neoplasm Spinal Cord Diseases T-Lymphocyte Taxes Testing Tropical Spastic Paraparesis Ubiquitination Vaccines Vascular Endothelial Growth Factors Viral Viral Genes Virus Replication antiviral immunity base cell motility cohort disorder risk gain of function genetic regulatory protein human migration inhibitor insight knock-down lentiviral-mediated loss of function migration neoplastic cell novel strategies novel therapeutic intervention receptor recruit small hairpin RNA small molecule small molecule inhibitor tax Gene Products transcription factor tumorigenesis validation studies

项目摘要

The retrovirus human T-cell leukemia virus type 1 (HTLV-1) is the etiological agent of adult T-cell leukemia/lymphoma (ATLL), an aggressive neoplasm that occurs in ~5% of infected individuals after a long latent period. HTLV-1 infection is also associated with a host of inflammatory diseases including HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). HTLV-1 Tax is a multifunctional trans-activating protein and key player in pathogenesis. Tax is required for viral gene expression by coordinating the recruitment of the CREB transcription factor and CBP/p300 co-activators to the 5’ viral long terminal repeat (LTR). Tax is also a potent oncogene and induces the persistent activation of the NF- kB pathway to drive the survival, expansion and persistence of HTLV-1-infected T cell clones. Emerging studies have revealed that the expression of HTLV-1 genes is highly dynamic, with prolonged periods of latency to evade antiviral immune responses. However, little is known about host proteins that regulate Tax expression or protein stability which may impact on viral gene expression, host antiviral immunity and the survival of HTLV-1-infected T cells. Furthermore, there is an urgent and unmet clinical need for novel therapeutic approaches for ATLL, a highly aggressive and lethal disease. We have conducted a kinome-wide shRNA screen to identify host factors important for the survival of an HTLV-1- transformed T cell line. The top hit in the screen was the tyrosine kinase receptor KDR/VEGFR2, which we have validated as a critical survival factor in a subset of HTLV-1-transformed T cell lines. Inhibition of KDR with shRNA or a small molecule inhibitor induced cell death selectively in KDR+ HTLV-1-transformed T cells. Furthermore, inhibition of KDR blunted the chronic activation of NF-kB and triggered the degradation of the Tax protein. In this exploratory application, we will investigate the mechanisms by which KDR signaling regulates Tax stability, as well as the role of KDR in the activation of oncogenic signaling pathways, cell survival and migration of HTLV-1- transformed T cells. The central hypothesis driving these investigations is that KDR activates oncogenic signaling pathways in HTLV-1-infected T cells that promote cell survival and the stability of the Tax protein. We will test this hypothesis experimentally with the following Specific Aims: (1) determine the oncogenic role of VEGFR2/KDR in HTLV-1-transformed T cells, and (2) determine how KDR signaling regulates Tax protein stability and viral gene expression. Completion of the proposed studies will provide new insight into the complex regulation of the HTLV-1 Tax oncoprotein and viral gene expression and may lead to new strategies to curtail the proviral load in HTLV-1-infected individuals.

逆转录病毒人类T细胞白血病1型（HTLV-1）是成年T细胞白血病/淋巴瘤（ATLL）的病因，这是一种侵袭性的肿瘤，在长期潜伏期后发生在约5％的感染个体中。 HTLV-1感染还与许多炎症性疾病有关，包括与HTLV-1相关的脊髓病/热带痉挛性瘫痪（HAM/TSP）。 HTLV-1税是一种多功能的反式激活蛋白和发病机理的关键参与者。通过协调将CREB转录因子和CBP/P300共激活因子募集到5'病毒长期重复（LTR）的募集来进行病毒基因表达所需的税收。税收也是潜在的癌基因，并引起NF-KB途径的持续激活，以驱动HTLV-1感染的T细胞克隆的存活，膨胀和持久性。新兴的研究表明，HTLV-1基因的表达是高度动态的，逃避抗病毒免疫调查的潜伏期延长。然而，关于调节税收表达或蛋白质稳定性的宿主蛋白知之甚少，这可能会影响病毒基因表达，宿主抗病毒药物和HTLV-1感染的T细胞的存活。此外，对ATLL的新型治疗方法（一种高度侵略性和致命的疾病）存在着紧急且未满足的临床需求。我们已经进行了整个Kinome shRNA筛选，以确定对HTLV-1转化的T细胞系生存至关重要的宿主因素。屏幕上的最高命中是酪氨酸激酶受体KDR/VEGFR2，我们已将其验证为HTLV-1-转化的T细胞系的一个关键存活因子。用shRNA或小分子抑制剂抑制KDR在KDR+ HTLV-1-转化的T细胞中选择性地诱导细胞死亡。此外，KDR的抑制作用削弱了NF-KB的慢性激活，并触发了税收蛋白的降解。在此探索性应用中，我们将研究KDR信号传导调节税收稳定性的机制，以及KDR在致癌信号通路的激活中的作用，HTLV-1-转化的T细胞的细胞存活和迁移。推动这些投资的中心假设是，KDR激活了HTLV-1感染的T细胞中的致癌信号传导途径，这些T细胞促进了细胞存活和税收蛋白的稳定性。我们将通过以下特定目的在实验中测试这一假设：（1）确定VEGFR2/KDR在HTLV-1转化的T细胞中的致癌作用，（2）确定KDR信号如何调节税收蛋白稳定性和病毒基因表达。拟议研究的完成将为HTLV-1税收癌蛋白和病毒基因表达的复杂调节提供新的见解，并可能导致新的策略减少HTLV-1感染的个体的临时负载。