Amplifying Radiation Potency Against Leukemic Stem Cells

增强针对白血病干细胞的放射效力

基本信息

批准号：
8224131
负责人：
FATIH M UCKUN
金额：
$ 21.14万
依托单位：
CHILDREN'S HOSPITAL OF LOS ANGELES
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-07-06 至 2014-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8224131
关键词：
Acute Lymphocytic Leukemia Adverse event Apoptosis Apoptotic B-Lymphocytes Biological Assay Biological Models Biological Products Bone Marrow CD19 gene Cell Line Cells Cessation of life Childhood Leukemia Development Disease-Free Survival Dose Drug Kinetics Extracellular Domain Goals Hematopoietic Stem Cell Transplantation In Situ Nick-End Labeling In Vitro Ionizing radiation Leukemic Cell Ligands Malignant Neoplasms Measures Mus NOEL Outcome Patients Proteins Radiation Radiation Tolerance Radiation therapy Radiation-Sensitizing Agents Recombinants Recurrence Regimen Relapse Research Research Project Grants Resistance SCID Mice Signal Transduction Specimen Staining method Stains Testing Therapeutic Toxic effect Treatment outcome Whole-Body Irradiation Work Xenograft Model annexin A5 chemotherapy effective therapy experience improved in vivo innovation leukemia leukemic stem cell novel pre-clinical radiation resistance repaired research study success

项目摘要

DESCRIPTION (provided by applicant): In this exploratory project, we are proposing to develop a new strategy to overcome radiation resistance of leukemic stem cells in B-lineage ALL using a novel recombinant biotherapeutic agent, namely CD19-Ligand, for selectively amplifying radiation-induced pro-apoptotic signaling. The long-term goal of the proposed research is to establish "personalized" radiation therapy regimens against relapsed B-lineage ALL employing a recombinant biotherapeutic agent to selectively increase the anti-leukemic potency of ionizing radiation. We hypothesize that the treatment outcome of relapsed B-lineage ALL patients can be improved by using recombinant CD19-Ligand in combination with TBI in the context of HSCT. Under Specific Aim 1, we will examine the effects of recombinant CD19-L on in vitro radiation resistance of radiation-resistant ALL cell lines as well as primary ALL cells from relapsed B-lineage ALL patients using quantitative flow cytometric apoptosis assays and clonogenic assays (Year 1 of the Project). We hypothesize that CD19-L will amplify radiation- induced pro-apoptotic BTK signals thereby markedly and selectively enhancing radiation-induced apoptosis of CD19+ B-lineage ALL cells as well as augmenting radiation-induced death of their clonogenic fraction. The radiation resistance of leukemic cells will be measured using our standard quantitative flow cytometric (CD19/Annexin V staining) and confocal (TUNEL) apoptosis assay platforms. Under Specific Aim 2, we will examine the effects of the CD19-L on in vivo radiation resistance of leukemic stem cells in primary bone marrow specimens from relapsed B-lineage ALL patients using SCID mouse xenograft models of relapsed B- lineage ALL and sublethal TBI (Year 2 of the Project). We anticipate that the use of CD19-L before and concomitant with radiation will markedly enhance the anti-leukemic potency of TBI in the context of HSCT. Likewise, the sequential administration of TBI and post-TBI CD19-L is expected to be more effective than TBI alone. We will first perform mouse toxicity and pharmacokinetics experiments to determine non-toxic dose levels of CD19-L and then examine the effects of CD19-L on the anti-leukemic potency of sublethal TBI (2 Gy) against leukemic stem cells in primary bone marrow specimens from relapsed patients as well as radiation- resistant B-lineage ALL cell lines in a SCID mouse xenograft model system. Our working hypothesis is that CD19-L plus TBI regimens will be more effective than TBI alone in improving the event-free survival outcome of SCID mice challenged with primary B-lineage ALL cells. We anticipate that the successful completion of this exploratory research project will provide the first preclinical proof-of-principle for a potentially paradigm-shifting therapeutic innovation against relapsed B-lineage ALL, whereby the radiation resistance of leukemic stem cells is overcome using recombinant CD19-L as a selective radiosensitizer that amplifies pro-apoptotic signaling after radiation. PUBLIC HEALTH RELEVANCE: Currently, the major challenge in the treatment of childhood leukemia is to cure patients who experience a recurrence of their cancer despite intensive chemotherapy. The purpose of the proposed research is the development of an effective treatment

描述（由申请人提供）：在这个探索性项目中，我们建议开发一种新策略来克服 B 系 ALL 中白血病干细胞的辐射抗性，使用一种新型重组生物治疗剂，即 CD19-配体，用于选择性放大辐射-诱导促凋亡信号传导。该研究的长期目标是针对复发性 B 系 ALL 建立“个性化”放射治疗方案，采用重组生物治疗剂选择性增加电离辐射的抗白血病效力。我们假设在 HSCT 背景下使用重组 CD19-配体与 TBI 相结合可以改善复发 B 系 ALL 患者的治疗结果。在具体目标 1 下，我们将使用定量流式细胞凋亡测定和克隆形成测定来检查重组 CD19-L 对耐辐射 ALL 细胞系以及来自复发 B 系 ALL 患者的原代 ALL 细胞的体外辐射耐受性的影响（项目第一年）。我们假设 CD19-L 将放大辐射诱导的促凋亡 BTK 信号，从而显着且选择性地增强辐射诱导的 CD19+ B 系 ALL 细胞的凋亡，并增加辐射诱导的其克隆部分的死亡。将使用我们的标准定量流式细胞术（CD19/Annexin V 染色）和共聚焦（TUNEL）细胞凋亡测定平台来测量白血病细胞的辐射耐受性。在具体目标 2 下，我们将使用复发 B 系 ALL 和亚致死 TBI 的 SCID 小鼠异种移植模型，检查 CD19-L 对复发 B 系 ALL 患者原代骨髓标本中白血病干细胞体内辐射抗性的影响（项目第二年）。我们预计，在 HSCT 背景下，在放疗之前和同时使用 CD19-L 将显着增强 TBI 的抗白血病效力。同样，TBI 和 TBI 后 CD19-L 的顺序给药预计比单独 TBI 更有效。我们将首先进行小鼠毒性和药代动力学实验以确定CD19-L的无毒剂量水平，然后检查CD19-L对亚致死TBI（2 Gy）针对原代骨髓中白血病干细胞的抗白血病效力的影响来自复发患者的标本以及 SCID 小鼠异种移植模型系统中的抗辐射 B 系 ALL 细胞系。我们的工作假设是，CD19-L 加 TBI 方案比单独 TBI 更有效地改善接受原代 B 系 ALL 细胞攻击的 SCID 小鼠的无事件生存结果。我们预计，这一探索性研究项目的成功完成将为针对复发性 B 系 ALL 的潜在范式转变治疗创新提供第一个临床前原理验证，从而使用重组 CD19- 克服白血病干细胞的辐射抗性。 L 作为选择性放射增敏剂，可在放射后放大促凋亡信号。公共卫生相关性：目前，儿童白血病治疗的主要挑战是治愈尽管进行强化化疗但癌症复发的患者。拟议研究的目的是开发有效的治疗方法