Amplifying Radiation Potency Against Leukemic Stem Cells

增强针对白血病干细胞的放射效力

• 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
• 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

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，我们建议制定一种新策略，以克服B-Linege中白血病干细胞的辐射抗性，所有这些都使用一种新型的重组生物疗法剂，即CD19-Ligand，即选择性扩增辐射诱导的辐射诱导的促疾病信号。拟议的研究的长期目标是建立“个性化”放射治疗方案，以防止复发的B-Linege所有使用重组生物治疗剂，以选择性地提高电离辐射的抗白血病效力。我们假设在HSCT的背景下，使用重组CD19-配体与TBI结合使用重组CD19-配体，可以改善所有患者的治疗结果。在特定目标1下，我们将检查重组CD19-L对抗辐射抗性的所有细胞系的体外辐射耐药性的影响，以及使用定量流式细胞仪凋亡分析和克隆生成分析（该项目的第1年）的所有患者复发B-Linege的主要细胞。我们假设CD19-L将放大辐射诱导的促凋亡BTK信号，从而显着增强CD19+ B-Lineage的辐射诱导的所有细胞的凋亡，并增强其子宫发作分数的辐射诱导的死亡。白血病细胞的辐射耐药性将使用我们的标准定量流式细胞仪（CD19/Annexin V染色）和共焦（TUNEL）凋亡测定平台进行测量。在特定的目标2下，我们将使用SCID小鼠异种移植物模型的Relapsed B-Linograpt模型（项目的第二年）（项目的第2年）中，研究CD19-L对重复B-Linege的原代骨髓样品中白血病干细胞的体内辐射抗性的影响。我们预计，在HSCT的背景下，使用CD19-L和辐射伴随的使用将显着提高TBI的抗白血病效力。同样，预计TBI和TBI CD19-L的顺序给药比单独使用TBI更有效。我们将首先执行小鼠的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solethal tbi（2 Gy）对重骨骨髓标本中的白血病干细胞的抗白血病效力的影响，以及来自辐射b-lineage blinineage in nocter nimeger nimerge nimerge ncen cin ncen ncen ncen cin cin。我们的工作假设是，CD19-L Plus TBI方案比单独使用TBI更有效地改善了由原代B-Linege所有细胞挑战的SCID小鼠的无事件生存结果。 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. 公共卫生相关性：目前，治疗儿童白血病的主要挑战是治疗尽管化学疗法进行了严重化学疗法，但经历了癌症的患者。拟议研究的目的是开发有效的治疗方法