c-Abl and PKC-eta in Cell Development and Leukemia

描述（由申请人提供）：发育中的B细胞在成功组装编码其抗原受体的基因后，经历受调节的细胞分裂和细胞凋亡。此外，监测这些受体的特异性，并向具有自身特异性潜力的发育中细胞发出信号，以编辑其受体或进行细胞凋亡。这项研究计划的重点是蛋白酪氨酸激酶，c-Abl，我们的初步数据和其他人的实验使我们相信，可能参与这些关键的发育过程，c-Abl是v-Abl的细胞同源物，v-Abl是Abelson小鼠白血病病毒（A-MuLV）的转化基因，导致小鼠急性B细胞白血病。在人类中，c-Abl参与疾病相关的染色体易位，在几种形式的白血病中产生BCR-Abl融合蛋白。我们建议通过追求两个特定的目标来测试关于Abl激酶在发育B细胞中的生物学功能及其在转化中的作用的假设。首先，我们将进行实验，旨在了解如何v-Abl破坏信号通路，阻断分化，并防止白血病小鼠前B细胞系的凋亡。这些实验将使用一种新的Abl酪氨酸激酶特异性抑制剂STI-571（Gleevec）、DNA微阵列和最近开发的逆转录病毒cDNA克隆策略CPR。其次，我们将测试关于c-Abl在正常小鼠B细胞发育期间在细胞增殖、活力、基因表达、前BCR信号传导、等位基因排斥、受体编辑和克隆缺失的调节中的作用的假设。我们将试图确定参与这些过程的Abl激酶的关键目标。这些实验将利用原代细胞培养系统和STI-571，以及ARG（ARG相关基因）和c-Abl中的无效突变。这些研究是重要的，因为c-Abl参与人类慢性髓细胞性白血病和急性淋巴细胞性白血病的病因学，以及Abl抑制剂STI-571在各种恶性肿瘤的临床治疗中的日益使用。

DESCRIPTION (provided by applicant): Developing B cells undergo regulated cell division and apoptosis in response to their success in assembling the genes encoding their antigen receptors. In addition, the specificity of these receptors is monitored and developing cells with the potential for self-specificity are signaled to either edit their receptors or undergo apoptosis. This research proposal focuses on a protein tyrosine kinase, c-Abl, which our preliminary data and the experiments of others lead us to believe may be involved in these key developmental processes, c-Abl is the cellular homologue of v-Abl, the transforming gene of the Abelson Murine Leukemia Virus (A-MuLV) which causes acute B cell leukemia in mice. In humans, c-Abl is involved in a disease-associated chromosomal translocation which generates the BCR-Abl fusion protein in several forms of leukemia. We propose to test hypotheses regarding the biological functions of the Abl kinase in developing B cells and its role in transformation through pursuit of two specific aims. First, we will perform experiments aimed at understanding how v-Abl disrupts signaling pathways, blocks differentiation, and prevents the apoptosis of leukemic murine pro-B cell lines. These experiments will use a newly available specific inhibitor of the Abl tyrosine kinase, STI-571 (Gleevec), DNA microarrays, and a recently-developed retroviral cDNA cloning strategy called CPR. Second, we will test hypotheses regarding the role of c-Abl in the regulation of cell proliferation, viability, gene expression, pre-BCR signaling, allelic exclusion, receptor editing and clonal deletion during normal murine B cell development. We will attempt to identify the critical targets of the Abl kinase involved in these processes. These experiments will take advantage of primary cell culture systems and STI-571, as well as available null mutations in ARG (Abl-related gene) and c-Abl. These studies are significant because of the involvement of c-Abl in the etiology of chronic myelogenous leukemia and acute lymphocytic leukemia in humans and the growing use of the Abl inhibitor STI-571 in the clinical treatment of various malignancies.