Translational Control of Leukemia Stem Cells - Resubmission - 1

白血病干细胞的转化控制 - 重新提交 - 1

基本信息

批准号：
10200716
负责人：
CHRISTOPHER Y PARK
金额：
$ 44.8万
依托单位：
NEW YORK UNIVERSITY SCHOOL OF MEDICINE
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：
2020-07-01 至 2025-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10200716
关键词：
Acute Myelocytic Leukemia Adult Acute Myeloblastic Leukemia Affect Antigens Biological Assay Biology Blast Cell CD34 gene CD47 gene Cell Death Cell surface Cells Clinical Complement Data Defect Diagnosis Disease Effector Cell Exhibits FRAP1 gene Gene Expression Genes Genetic Genetic Translation Growth Hematopoiesis Hematopoietic stem cells Human Immune Impairment In Vitro Informal Social Control Intervention Knockout Mice Messenger RNA Methods Modeling Molecular Monoclonal Antibodies Outcome Pathway interactions Patients Play Polyribosomes Population Positioning Attribute Process Protein Biosynthesis Proteins Publishing Reagent Regulation Relapse Residual Neoplasm Residual state Resistance Ribosomal Proteins Ribosomes Role Sampling Signal Transduction Signaling Molecule Sirolimus Testing Therapeutic Transcript Translating Translational Regulation Translational Repression Translations Up-Regulation Work Xenograft Model base cancer stem cell chemotherapy computational pipelines curative treatments cytotoxic cytotoxicity experimental study hematopoietic stem cell self-renewal improved in vivo inhibitor/antagonist insight knock-down leukemia leukemia initiating cell leukemic stem cell mTOR Inhibitor novel novel strategies novel therapeutic intervention polysome profiling programs prospective recruit self-renewal src-Family Kinases stem cell biomarkers stem cell function stem cell self renewal stem cell therapy therapeutic target thymic shared antigen-1 tool transcriptome sequencing translational impact treatment response

项目摘要

Approximately 13,000 new cases of adult AML are diagnosed each year in the U.S. Unfortunately for these patients, treatment options have remained essentially unchanged for 30 years, and clinical outcomes remain poor. Moreover, little is known about the genes that regulate leukemia stem cells (LSCs), which represent the population of blasts that is resistant to chemotherapy and are critical for maintaining disease and re-initiating disease after therapy. Thus, eradication of the LSC is a prerequisite for cure. We recently identified a novel LSC antigen, CD99, that is expressed in the vast majority (~85%) of human AMLs [3]. We have shown that CD99 is expressed on leukemic blasts and can be used to prospectively separate leukemic blasts from residual hematopoiesis, similar to LSC antigens such as TIM3 and CD47, but CD99 exhibits several unique features: 1) CD99 is the most commonly expressed LSC antigen; 2) CD99 does not just mark LSCs, but regulates blast growth and survival; 3) CD99 allows isolation of LSCs from blasts with CD99hi blasts enriched ~10-100 fold for leukemia initiating-cell activity over CD99low cells; 4) CD99 is the only LSC antigen that can identify LSCs in both CD34+ and CD34- AMLs; and, 5) Novel monoclonal antibodies (mAbs) against CD99 induce cell death directly by activating Src-family kinases (SFKs). We have evaluated the consequences of CD99 loss in both LSCs and hematopoietic stem cells (HSCs). Our studies indicate that decreased expression of CD99 in both LSCs and HSCs results in global upregulation of protein synthesis and loss of self-renewal. Moreover, cytotoxic mAbs against CD99 mimic the effects of CD99 loss, activating protein synthesis and inducing similar gene expression changes to those observed in CD99 null HSCs or CD99low blasts in most genetic subtypes of AML tested. Collectively, these data support a model in which LSCs require highly regulated levels of protein synthesis, similar to HSCs, and based on our work in normal HSCs, we expect these alterations in translation to result in selective recruitment of mRNA’s to active translating ribosomes (polysomes). Overall, we hypothesize that CD99 constrains the translation of specific mRNA’s, thereby promoting a translational program required for LSC self-renewal. Given our ability to enrich for LSCs, our group is in a unique position to investigate the role of mRNA translation in LSC function. We have painstakingly optimized methods to perform polysome profiling and RNA- sequencing from polysome fractions from small numbers of cells, and we have developed a computational pipeline to identify mRNA’s that are preferentially translated in LSCs. These tools, in combination with unique reagents such as our CD99 KO mice and cytotoxic CD99 mAbs that mimic CD99 loss, place us in an excellent position to investigate how CD99 regulates translation in LSCs. Understanding the molecular pathways that regulate protein synthesis has the potential to help better characterize a poorly understood process in AML biology and to credential targeting translation using mAbs as a potential therapeutic strategy in AML.

美国每年诊断出大约 13,000 例新的成人 AML 病例。 30年来，治疗方案基本保持不变，临床结果也保持不变此外，人们对调节白血病干细胞（LSC）的基因知之甚少。对化疗有抵抗力并且对于维持疾病和重新启动至关重要的原始细胞群因此，根除LSC是治愈的先决条件。我们最近发现了一种新的 LSC 抗原 CD99，它在绝大多数 (~85%) 人类中表达我们已经证明 CD99 在白血病原始细胞上表达，可用于前瞻性分离。来自残余造血的白血病母细胞，类似于 TIM3 和 CD47 等 LSC 抗原，但 CD99 表现出几个独特的功能：1）CD99是最常表达的LSC抗原；2）CD99不仅仅标记 3) CD99允许用CD99hi母细胞从母细胞中分离LSC 白血病起始细胞活性比 CD99low 细胞丰富约 10-100 倍；4) CD99 是唯一的 LSC 抗原可以识别 CD34+ 和 CD34- AML 中的 LSC；5) 新型单克隆抗体 (mAb)； CD99 通过激活 Src 家族激酶 (SFK) 直接诱导细胞死亡。我们评估了 LSC 和造血干细胞 (HSC) 中 CD99 缺失的后果。研究表明，LSC 和 HSC 中 CD99 表达下降会导致整体上调蛋白质合成和自我更新的丧失此外，针对 CD99 的细胞毒性单克隆抗体模仿 CD99 的作用。损失，激活蛋白质合成并诱导与 CD99 null 中观察到的相似的基因表达变化大多数测试的 AML 基因亚型中的 HSC 或 CD99low 母细胞总体而言，这些数据支持以下模型。与 HSC 类似，LSC 高度需要受调节的蛋白质合成水平，并且基于我们的工作对于正常的 HSC，我们预计这些翻译改变会导致选择性招募 mRNA 来激活总体而言，我们追求 CD99 限制特定的翻译。 mRNA，从而促进 LSC 自我更新所需的翻译程序。鉴于我们富集 LSC 的能力，我们的团队在研究 mRNA 的作用方面处于独特的地位我们精心优化了执行多核糖体分析和 RNA 分析的方法。对少量细胞的多核糖体部分进行测序，我们开发了一种计算方法结合独特的工具来识别在 LSC 中优先翻译的 mRNA。我们的 CD99 KO 小鼠和模拟 CD99 损失的细胞毒性 CD99 mAb 等试剂使我们处于极好的状态研究 CD99 如何调节 LSC 翻译的分子途径。调节蛋白质合成有可能帮助更好地描述 AML 中一个鲜为人知的过程生物学和使用单克隆抗体作为 AML 潜在治疗策略的凭证靶向翻译。