Cyclic nucleotide phosphodiesterases isoforms as novel biomarkers in CLL

描述（由申请人提供）：慢性淋巴细胞白血病（CLL）是成人白血病的最常见形式，表现出高度可变的临床过程，从快速侵袭性到惰性行为。具有侵袭性CLL的患者需要早期治疗，而具有惰性CLL的患者通常表现出长期疾病而不需要治疗。目前，Rai和Binet标准的临床分期仍然是确定预后和治疗指征的基础。然而，根据这些标准定义，约50%的早期疾病患者发展为更晚期的疾病并死于CLL或其并发症。重要的是，Rai和Binet分期系统关注的是白血病细胞的数量，而不是特征。新的预后指标，如免疫球蛋白可变重链区（IgVH）的突变状态，CD 38和ZAP-70的表达与白血病细胞的分子特征有关，并已被报道可预测临床病程和总生存期。IgVH状态是一个强有力的独立预后因素，但IgVH状态分析是费力的，昂贵的，大多数临床实验室无法访问。发现白血病细胞表达CD 38和ZAP-70与未突变IgVH基因的表达相关，以预测不良预后。然而，没有标准的、广泛使用的程序来评估CD 38和ZAP-70表达。对于B-CLL患者的常规评估，获得最佳预后信息的成本和时间有效的方法因此是期望的，但尚不存在。环核苷酸磷酸二酯酶（PDE）催化cAMP和/或cGMP的水解，从而控制它们的细胞内水平和调节包括细胞生长和死亡的功能的能力。PDE同工型在病变细胞中的差异表达具有影响细胞生理学和鉴定新的药物靶点的潜力。我的初步数据表明，CLL细胞有一个独特的表达PDE亚型的配置文件。因此，这种独特的PDE同种型谱与CLL中的恶性B细胞相关，并可提供可用作该疾病的生物标志物的PDE“特征”。QPCR（quantitative real-time reverse transcription-PCR）已成为一种广泛用于检测和定量RNA靶标的技术，并且越来越多地用于新型临床诊断测定。QPCR方法相对简单快速，具有成本效益，但敏感性和特异性，因此建议开展研究以解决以下具体目标：1. PDE mRNA表达模式可作为分类惰性和侵袭性CLL患者的预后标志物。2.在B-CLL患者中，PDE 7 B的mRNA表达或PDE 7 B mRNA表达与其他PDE亚型的表达的比率可以预测至开始治疗的时间或对治疗的反应。这些目标的成功完成将为CLL提供一种新的生物标志物，以帮助诊断，预后，预测对治疗的反应时间，并可能为这种疾病提出新的治疗方法。公共卫生相关性：慢性淋巴细胞白血病（CLL）是成人白血病的最常见形式，其显示出高度可变的临床过程，从需要早期治疗的快速侵袭性到表现出不需要治疗的长期疾病的惰性行为。目前，不存在区分这两种形式的CLL的成本和时间有效的方法。基于初步研究，拟议的研究旨在量化和建立环核苷酸磷酸二酯酶（PDE）亚型，其表达在CLL中发生独特变化，不仅可以提供生物标志物，还可以为这种疾病提供药物靶标。

DESCRIPTION (provided by applicant): Chronic lymphocytic leukemia (CLL), the most common form of adult leukemia, shows a highly variable clinical course spanning from rapidly aggressive to indolent behavior. Patients with aggressive CLL require early treatment while those with indolent CLL generally exhibit a long-lived disease without need of therapy. Currently, clinical staging by the Rai and Binet criteria remains the foundation for determining prognosis and indication for treatment. However, ~50% of patients with early-stage disease, as defined by those criteria, develop more advanced disease and die of CLL or its complications. Importantly, the Rai and Binet staging systems focus on the quantity, rather than on the characteristics, of the leukemic cells. New prognostic indicators, such as the mutational status of the immunoglobulin variable heavy chain region (IgVH), expression of CD38 and ZAP-70 are linked to the molecular characteristics of leukemic cells and have been reported to predict the clinical course and overall survival. IgVH status is a strong independent prognostic factor but IgVH status analysis is laborious, costly and inaccessible for most clinical laboratories. Leukemia-cell expression of CD38 and ZAP-70 was found to correlation with the expression of unmutated IgVH genes to predict a poor prognosis. However, there are no standard, widely used procedures to assess CD 38 and ZAP-70 expression. For routine evaluation of B-CLL patients, a cost- and time-efficient method to obtain optimal prognostic information is thus desirable but does not yet exist. Cyclic nucleotide phosphodiesterases (PDE) catalyze the hydrolysis of cAMP and/or cGMP, thereby controlling their intracellular levels and ability to regulate functions that include cell growth and death. The differential expression of PDE isoforms in diseased cells has the potential to influence cell physiology and identify new drug targets. My preliminary data indicate that CLL cells have a unique profile of expression of PDE isoforms. This unique PDE isoform profile thus relates to the malignant B cells in CLL and may provide a PDE "signature" that could serve as a biomarker for this disease. QPCR (quantitative real-time reverse transcription-PCR) has become a widely used technique for the detection and quantification of RNA targets and is increasingly used in novel clinical diagnostic assay. QPCR methods are relatively simple and rapid, cost-effective, yet sensitive and specific, therefore propose to undertake studies to address the following Specific Aims: 1. The PDE mRNA expression pattern may serve as a prognostic marker to classify patients with indolent and aggressive CLL. 2. The mRNA expression of PDE7B or the ratio of PDE7B mRNA expression vs. that of other PDE isoforms may predict time to initiation of treatment, or response to treatment, in B-CLL patients. Successful completion of these aims will provide a new biomarker in CLL to aid in the diagnosis, prognosis, prediction of time to an response to treatment and possibly suggest new therapeutic approaches for this disease. PUBLIC HEALTH RELEVANCE: Chronic lymphocytic leukemia (CLL), the most common form of adult leukemia, shows a highly variable clinical course spanning from rapidly aggressive, requiring early treatment to indolent behavior, which presents a long- lived disease without need of therapy. Currently, a cost and time efficient method to differentiate between these two forms of CLL does not exist. Based on preliminary studies the proposed research seeks to quantify and establish that cyclic nucleotide phosphodiesterases (PDE) isoforms whose expression is uniquely changed in CLL, may not only provide a biomarker, but also provide the drug target for this disease.