Role of Sialic Acid Modification in ALL Survival and Drug Resistance

唾液酸修饰在 ALL 生存和耐药性中的作用

• 批准号: 8717591
• 负责人: JOHN H GROFFEN
• 金额: $ 25.81万
• 依托单位: CHILDREN'S HOSPITAL OF LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-04-01 至 2018-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8717591
• 关键词: Acetylation; Acute Lymphocytic Leukemia; Address; Antioxidants; Apoptosis; Apoptotic; Bone Marrow; Cell Death; Cell Survival; Cell surface; Cells; Cessation of life; Cleaved cell; Coculture Techniques; Core Protein; Data; Development; Drug resistance; Environment; Excision; Glycolipids; Glycoproteins; Growth; Human; Immune; In Vitro; Kinetics; Lead; Lectin; Lipids; Location; Malignant Neoplasms; Mass Spectrum Analysis; Mediating; Mitochondria; Modeling; Modification; Molecular Conformation; Mus; Pathway interactions; Patients; Pharmaceutical Preparations; Pre-B Acute Lymphoblastic Leukemia; Proliferating; Property; Proteins; Reactive Oxygen Species; Relapse; Resistance development; Role; Sialic Acids; Sialoglycoproteins; Signal Transduction; Signal Transduction Pathway; Stress; Stromal Cells; Structure; Surface; Transplantation; Treatment Failure; Variant; Wild Type Mouse; Work; age group; age related; cancer type; cell growth; chemotherapy; drug relapse; drug sensitivity; esterase; extracellular; glycosylation; innovation; insight; leukemia; melanoma; mouse model; novel; novel strategies; overexpression; public health relevance; research study; sialylation; sugar; therapy development

DESCRIPTION (provided by applicant): Treatment failure and relapse in acute lymphoblastic leukemia (ALL) is promoted by bone marrow stromal cells that provide growth stimulation under steady-state conditions and anti-apoptotic signals when the ALL cells are treated with chemotherapy. In the previous period of support, this project has made significant advances in understanding how ALL cells respond when they are simultaneously challenged by drug treatment and provided with stromal support. Modification of cell surface molecules through sialylation regulates interactions of immune cells with the microenvironment and modulates signal transduction strength. Our preliminary studies show abnormally high levels of sialic acid 9-O-acetylation on both mouse and human ALL cells, which is consistently and significantly increased as they develop drug resistance. Strikingly, human ALL cells proliferating in the protective bone marrow microenvironment of transplanted mice were eradicated when 9-O-acetylation was removed through activation of a specific esterase that cleaves the R9 acetyl group from sialic acid. We hypothesize that ALL cells generate 9-O-acetylated, sialic acid-modified glycoproteins and glycolipids as a mechanism of protection against spontaneous and drug- induced apoptosis. To address this, Aim 1 will investigate intracellular pathways activated during death due to 9-O-acetylation removal from Sias in pre-B ALL cells, by expression of inducible 9-O-acetyl esterases in human pre-B ALL and mouse wild type and GD3-/- pre-B ALL cells in co-culture with protective stroma. Aim 2 will determine how increased 9-O-acetylation levels of Sias contribute to drug resistance development by comparing drug sensitivity and resistance in pre-B ALL cells with different 9-O-acetylated sialic acid levels in vitro and in mous models. The specific contribution of GD3 will be examined in st8sia1-/- pre-B ALL cells. Aim 3 will determine how acetylation of Sias changes the reactivity of sialoglycoproteins or of GD3 to a conformation favorable for ALL cell survival. The effect of the oxidative state of GD3 on its pro-apoptotic activity will be evaluated in st8sia1-/- pre-B ALL cells that lack endogenous GD3. We will also characterize critical sialoglycoproteins that are 9-O-acetylated in human and mouse ALL cells for subcellular location, induction kinetics upon drug treatment and development of drug resistance using the C. antennarius lectin that specifically detects this modification. Immunoaffinity purification and mass spectrometry will be used to identify the core proteins that are modified by 9-O-acetyl sialylation and are upregulated as ALL cells develop drug resistance in the presence of stromal support in vitro. 9-O-sialylation has not been examined in drug resistance in ALL but our data show it is extremely relevant to their growth and survival. These innovative studies will yield new insight into the mechanisms through which ALL cells withstand drug treatment and lead to novel targets and approaches to treat this and other types of cancer.

描述（由申请方提供）：骨髓基质细胞促进急性淋巴细胞白血病（ALL）的治疗失败和复发，骨髓基质细胞在稳态条件下提供生长刺激，并在ALL细胞接受化疗时提供抗凋亡信号。在上一个支持期间，该项目在理解ALL细胞在同时受到药物治疗和基质支持的挑战时如何反应方面取得了重大进展。通过唾液酸化修饰细胞表面分子调节免疫细胞与微环境的相互作用并调节信号转导强度。我们的初步研究显示，小鼠和人ALL细胞上的唾液酸9-O-乙酰化水平异常高，随着它们产生耐药性，唾液酸9-O-乙酰化水平持续显著增加。引人注目的是，当通过激活从唾液酸切割R9乙酰基的特异性酯酶来去除9-O-乙酰化时，在移植小鼠的保护性骨髓微环境中增殖的人ALL细胞被根除。我们假设ALL细胞产生9-O-乙酰化、唾液酸修饰的糖蛋白和糖脂，作为防止自发性和药物诱导的细胞凋亡的机制。为了解决这一问题，目标1将通过在与保护性基质共培养的人前B ALL和小鼠野生型和GD 3-/-前B ALL细胞中表达诱导型9-O-乙酰酯酶，研究由于前B ALL细胞中Sias的9-O-乙酰化去除而导致死亡期间激活的细胞内途径。目的2将通过在体外和小鼠模型中比较具有不同9-O-乙酰化唾液酸水平的pre-B ALL细胞的药物敏感性和耐药性，确定Sias的9-O-乙酰化水平增加如何有助于耐药性的发展。将在st 8 sia 1-/- pre-B ALL细胞中检查GD 3的特异性贡献。目的3将确定Sias的乙酰化如何改变唾液酸糖蛋白或GD 3的反应性，使其成为有利于ALL细胞存活的构象。将在缺乏内源性GD 3的st 8 sia 1-/- pre-B ALL细胞中评价GD 3的氧化状态对其促凋亡活性的影响。我们还将使用C. Antennarius凝集素特异性检测这种修饰。免疫亲和纯化和质谱将用于鉴定通过9-O-乙酰基唾液酸化修饰的核心蛋白，并且在体外基质支持物存在的情况下，随着ALL细胞产生耐药性而上调。9-O-唾液酸化尚未在ALL的耐药性中进行研究，但我们的数据显示它与他们的生长和生存非常相关。这些创新研究将对ALL细胞耐受药物治疗的机制产生新的见解，并导致治疗这种和其他类型癌症的新靶点和方法。