Microenvironment-Leukemia Communication Through Lectins

通过凝集素的微环境-白血病通讯

• 批准号: 8628812
• 负责人: JOHN H GROFFEN
• 金额: $ 32.61万
• 依托单位: CHILDREN'S HOSPITAL OF LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-03-01 至 2018-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8628812
• 关键词: Ablation; Acute Lymphocytic Leukemia; Affect; Affinity; Antineoplastic Agents; Apoptotic; Attenuated; B-Lymphocytes; Binding; Binding Proteins; CD19 gene; Carbohydrates; Cell Surface Proteins; Cell Surface Receptors; Cell Survival; Cell physiology; Cell surface; Cells; Communication; Data; Development; Drug resistance; Excision; Galectin 3; Gene Expression; Genes; Glycolipids; Hematopoietic; Homing; Human; Immune system; In Vitro; Investigation; Lead; Lectin; Leukemic Cell; Ligand Binding; Ligands; Location; Mediating; Molecular; Mus; Mutation; Oncogenic; PTPRC gene; Pathway interactions; Pharmaceutical Preparations; Phosphotyrosine; Play; Polysaccharides; Pre-B Acute Lymphoblastic Leukemia; Protein Tyrosine Kinase; Proteins; Proteomics; Relapse; Signal Transduction; Stromal Cells; Structure; Testing; Transplantation; Treatment Failure; Vincristine; bcr-abl Fusion Proteins; cancer type; carbohydrate binding protein; cell stroma; cell transformation; cell type; extracellular; in vivo; leukemia; oncogene addiction; outcome forecast; poly-N-acetyllactosamine; public health relevance; research study

DESCRIPTION (provided by applicant): Prognosis of Ph-positive acute lymphoblastic leukemia (ALL) remains poor because of frequent treatment failure and rapid relapse. ALL cells are significantly protected against drug treatment by stromal cells in their microenvironment, but the molecular signals that mediate the protection are not well-defined. All cells, and in particula cells of the immune system, are covered by a dense layer of carbohydrate-modified proteins and glycolipids, of which the function has not been explored. However, the first step in the communication between ALL cells and the stroma takes place through cell surface structures, of which carbohydrates are likely to play key roles. Our preliminary data show that the polyLacNAC-binding lectin Galectin-3 (Gal3) is part of the microenvironment created by stromal cells and identify extracellular Gal3 as a communication molecule between ALL cells and the stroma that protects ALL cells against drug treatment. We hypothesize that Gal3 in the ALL microenvironment is a molecular communicator that promotes Ph-positive ALL cell survival through extracellular lattice formation of glycosylated cell surface proteins and intracellularly b interactions with Bcr/Abl. Corollaries of this hypothesis are: Removal of Galectin-3 will 1) interrupt an important signal between these cell types and 2) will generate ALL cells that are more sensitive to drug treatment. The following Aims, with independent experiments that will be studied concurrently, will test these predictions: Aim 1 will determine the extracellular component of the signal by identification of the cell surface ligands/binding partners of Gal3 on Ph-positive ALL cells using different complementary approaches. Aim 2 will investigate the intracellular component of the signal by examining molecular interactions between Bcr/Abl and Gal3 and their effects on ALL cell survival. Aim 3 will determine the significance of extracellular and intracellular Gal3 to pre-B ALL cell function both in vitro, by comparing gene expression in gal3-/- and gal3+/+ pre-B ALL cells, in these cells stimulated with exogenous Gal3, and treated with nilotinib and in vivo through transplant of gal3-/- and gal3+/+ pre-B ALL cells into gal3 -/- and +/+ recipients and comparing homing, proliferation and the effect of vincristine and nilotinib treatment. These experiments together will be the first to fully characterize the significance of Gal3 in any type of cancer, and specifically will tease apart the function of this carbohydrate-binding protein in its extracellular location as communication messenger between stroma and ALL cells and in its intracellular location as an anti-apoptotic molecule.

描述（由申请人提供）：由于频繁的治疗失败和快速的复发，Ph 阳性急性淋巴细胞白血病（ALL）的预后仍然很差。所有细胞在其微环境中都受到基质细胞的显着保护，免受药物治疗，但介导这种保护的分子信号尚不明确。所有细胞，特别是免疫系统的细胞，都被一层致密的碳水化合物修饰蛋白质和糖脂覆盖，其功能尚未被探索。然而，所有细胞和基质之间通讯的第一步是通过细胞表面结构进行的，其中碳水化合物可能发挥关键作用。我们的初步数据表明，polyLacNAC 结合凝集素 Galectin-3 (Gal3) 是基质细胞创建的微环境的一部分，并将细胞外 Gal3 确定为 ALL 细胞和基质之间的通讯分子，可保护 ALL 细胞免受药物治疗。我们假设 ALL 微环境中的 Gal3 是一种分子通讯器，通过糖基化细胞表面蛋白的细胞外晶格形成以及与 Bcr/Abl 的细胞内相互作用来促进 Ph 阳性 ALL 细胞的存活。这一假设的推论是：去除 Galectin-3 将 1) 中断这些细胞类型之间的重要信号，2) 将产生对药物治疗更敏感的 ALL 细胞。以下目标以及将同时研究的独立实验将测试这些预测： 目标 1 将通过使用不同的互补方法识别 Ph 阳性 ALL 细胞上 Gal3 的细胞表面配体/结合伴侣来确定信号的细胞外成分。目标 2 将通过检查 Bcr/Abl 和 Gal3 之间的分子相互作用及其对 ALL 细胞存活的影响来研究信号的细胞内成分。目标 3 将确定细胞外的重要性 通过比较 gal3-/- 和 gal3+/+ pre-B ALL 细胞中的基因表达，在体外观察细胞内 Gal3 与 pre-B ALL 细胞的功能，这些细胞用外源 Gal3 刺激，并用尼罗替尼处理，并通过移植在体内进行将 gal3-/- 和 gal3+/+ pre-B ALL 细胞转化为 gal3 -/- 和 +/+ 受体，并比较归巢、增殖以及长春新碱和尼洛替尼治疗。这些实验将首次全面表征 Gal3 在任何类型癌症中的重要性，并将特别阐明这种碳水化合物结合蛋白在其细胞外位置作为基质和 ALL 细胞之间的通讯信使及其在细胞内位置的功能作为抗凋亡分子。