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：
10442530
负责人：
CHRISTOPHER Y PARK
金额：
$ 43.91万
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/10442530
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 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 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.

不幸的是，每年在美国诊断出大约13,000例新的成人AML病例患者，治疗选择基本上保持了30年，并且临床结果仍然存在贫穷的。此外，对调节白血病干细胞（LSC）的基因知之甚少，该基因代表了对化学疗法有抵抗力的爆炸群体，对于维持疾病和重新发判至关重要治疗后的疾病。那是消除LSC是治愈的先决条件。我们最近确定了一种新型的LSC抗原CD99，该抗原在人类的绝大多数（〜85％）中表示 AML [3]。我们已经表明，CD99在白血病爆炸上表示，可用于前瞻性分开残留造血的白血病爆炸，类似于LSC抗原，例如TIM3和CD47，但CD99展示几个独特的特征：1）CD99是最常见的LSC抗原； 2）CD99不只是标记 LSC，但调节爆炸生长和生存； 3）CD99允许用CD99HI爆炸从爆炸中分离LSC 在CD99LOW细胞上，白血病的富集〜10-100倍启动细胞活性； 4）CD99是唯一的LSC抗原可以识别CD34+和CD34-AML中的LSC； 5）针对的新型单克隆抗体（mAb） CD99通过激活SRC家庭激酶（SFK）直接诱导细胞死亡。我们已经评估了LSC和造血干细胞（HSC）中CD99损失的后果。我们的研究表明，LSC和HSC中CD99表达的降低导致全球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mAb模拟CD99的影响损失，激活蛋白质合成并诱导与CD99 NULL观察到的基因表达相似的基因表达变化在AML测试的大多数遗传亚型中，HSC或CD99LOW爆炸。总的来说，这些数据支持模型哪些LSC需要高度调节的蛋白质合成水平，类似于HSC，并根据我们的工作正常的HSC，我们希望这些翻译中的这些改变会导致mRNA的选择性募集到活动翻译核糖体（多个）。总体而言，我们假设CD99限制了特定的翻译 mRNA的，从而促进了LSC自我更新所需的翻译程序。鉴于我们能够丰富LSC，我们的小组处于独特的位置来研究mRNA的作用 LSC功能中的翻译。我们有精心优化的方法来执行多元体分析和RNA- 来自多数单元的多聚体组分数的测序，我们已经开发了一个计算识别LSC中最好翻译的mRNA的管道。这些工具，结合独特试剂，例如我们的CD99 KO小鼠和模仿CD99损失的细胞毒性CD99 mAb，将我们置于极好的研究CD99如何调节LSC中的翻译的位置。了解分子途径调节蛋白质合成有可能帮助更好地表征AML中不良理解的过程生物学和使用MAB作为AML的潜在治疗策略的鉴定靶向翻译。