Inducible NOS as a Treatment Target in CLL

描述：（申请人的摘要）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 超过30%的病例。CLL的特征在于 处于细胞周期GO的非分裂CD 5 + B细胞。目前，这是一个 无法治愈的恶性肿瘤;非常需要对疾病的新见解 机制等一氧化氮（NO）是由L-精氨酸通过酶在体内产生的 一氧化氮合酶（NOS）。NO有多种作用，在 生理学和病理学。最近的研究表明，NO抑制 凋亡我们已经发现人类CLL细胞自发地表达高水平的 诱导型一氧化氮合酶（NOS 2）mRNA和蛋白质水平， 高NOS酶活性。 当CLL细胞与NOS抑制剂一起培养时， 与凋亡相关的杀伤。该提案的具体目标是： (1)确定CLL患者体内NO产生是否增加， 体内NO产生是否与CLL细胞中的NOS 2表达相关， 疾病的阶段和疾病的子集。我们将测量血清和尿液 CLL患者中稳定的NO催化剂亚硝酸盐和硝酸盐水平， 并与CLL细胞NOS活性和NOS 2抗原含量相关， 疾病的临床阶段。(2)确定患者的CLL细胞的敏感性 各种NOS抑制剂和NO猝灭剂。我们将分析CLL细胞， 用选择的NOS（NOS 2）处理后的体外存活率和凋亡 特异性和非特异性）抑制剂和NO猝灭剂。我们亦会研究 将NOS抑制剂和NO淬灭剂与常规的 化疗剂。(3)确定NOS 2表达的机制 在CLL细胞中增加。我们将确定NOS 2 mRNA的增加是否 表达是由于mRNA转录或稳定化的改变， 是否存在已知的转录因子的组成性激活， 改变NOS 2 mRNA转录。 NOS 2和NO代表了CLL治疗的新分子靶点， 实现拟议的目标可以使人们更深入地了解 CLL的发病机制。此外，由于NOS抑制剂和NO 淬灭剂/清除剂现在被安全地用于正常的早期试验中， 志愿者和其他疾病的患者，我们的工作可能会导致快速 在CLL患者中开始这些药物的试验。

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.