Inducible NOS as a Treatment Target in CLL

描述：(申请人摘要)慢性淋巴细胞白血病(CLL)， 在北美和欧洲最常见的白血病，占更多 占所有案件的30%以上。CLL的特点是积累了 CD5B细胞在细胞周期中处于GO状态。这是当前的 无法治愈的恶性肿瘤；非常需要对疾病有新的见解 机械装置。一氧化氮(NO)是在体内由L精氨酸通过该酶产生的 没有合酶(NOS)。NO具有多个动作，这些动作在 生理学和病理学。最近的研究表明，NO抑制了 细胞凋亡。我们发现人类CLL细胞自发地表达高水平 诱导型一氧化氮合酶(NOS2)的mRNA和蛋白水平，并具有 高一氧化氮合酶活性。 当CLL细胞与一氧化氮合酶抑制剂共同培养时，有较高水平的细胞 杀戮与细胞凋亡有关。这项建议的具体目的是： (1)确定慢性淋巴细胞性白血病患者体内一氧化氮的产生是否增加，以及 CLL细胞体内NO的产生是否与NOS2的表达相关 疾病的阶段和疾病的亚类。我们会测量血清和尿液 慢性淋巴细胞性白血病患者稳定一氧化氮分解代谢产物亚硝酸盐和硝酸盐的水平 并与CLL细胞一氧化氮合酶活性、NOS2抗原含量及 疾病的临床分期。(2)测定患者CLL细胞的敏感性 对各种一氧化氮合酶抑制剂和无猝灭剂。我们将分析CLL细胞在 经选择的一氧化氮合酶(NOS2)处理后的体外存活和细胞凋亡 特异性和非特异性)抑制剂和无猝灭剂。我们还将调查 一氧化氮合酶抑制剂和NO猝灭剂与常规药物联合应用的效果 化疗药物。(3)确定NOS2表达的机制 在CLL细胞中增加。我们将确定NOS2 mRNA的增加是否 表达是由于mRNA转录或稳定的改变，以及 是否存在已知的转录因子的结构性激活 改变NOS2基因转录。 NOS2和NO是治疗慢性淋巴细胞性白血病的新分子靶点， 实现拟议的目标可能会使我们更深入地了解 慢性淋巴细胞性白血病的发病机制。此外，由于一氧化氮合酶抑制剂和一氧化氮 猝灭剂/清道夫现在在正常情况下的早期试验中安全使用 在志愿者和其他疾病患者中，我们的工作可能会导致快速 开始在慢性淋巴细胞性白血病患者中使用这些药物进行试验。

DESCRIPTION: (Applicant's Abstract) Chronic lymphocytic leukemia (CLL), the most common form of leukemia in North America and Europe, accounts for more than 30 percent of all cases. CLL is characterized by the accumulation of non-dividing CD5+ B cells in GO of the cell cycle. This is currently an incurable malignancy; there is a great need for new insights into disease mechanisms. Nitric oxide (NO) is produced in vivo from L-arginine by the enzyme NO synthase (NOS). NO has multiple actions that play important roles in physiology and pathology. Recent work has demonstrated that NO inhibits apoptosis. We have discovered that human CLL cells spontaneously express high levels of inducible nitric oxide synthase (NOS2) mRNA and protein, and have high NOS enzyme activity. When the CLL cells are cultured with NOS inhibitors, there is high level cell killing associated with apoptosis. The specific aims of the proposal are to: (1) Determine if in vivo NO production is increased in patients with CLL, and whether in vivo NO production correlates with NOS2 expression in CLL cells, stage of disease, and subsets of disease. We will measure serum and urine levels of the stable NO catabolites nitrite and nitrate in patients with CLL, and correlate levels with CLL cell NOS activity & NOS2 antigen content and clinical stage of disease. (2) Determine the sensitivity of patients' CLL cells to a variety of NOS inhibitors and NO quenchers. We will analyze CLL cells in vitro for viability and apoptosis after treatment with selected NOS (NOS2 specific and nonspecific) inhibitors and NO quenchers. We will also investigate the effects of combining NOS inhibitors & NO quenchers with conventional chemotherapeutic agents. (3) Determine the mechanism by which NOS2 expression is increased in CLL cells. We will determine whether the increases in NOS2 mRNA expression are due to alterations in mRNA transcription or stabilization, and whether there is constitutive activation of transcription factors known to alter NOS2 mRNA transcription. NOS2 and NO represent new molecular targets for treatment in CLL, Accomplishment of the proposed aims may provide a deeper understanding of the mechanisms of disease in CLL. Furthermore, since NOS inhibitors and NO quenchers/scavengers are now being used safely in early trials in normal volunteers and in patients with other diseases, our work may lead to rapid initiation of trials with these agents in CLL patients.