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，经历受调控的细胞分裂和凋亡。此外，监测这些受体的特异性，并向具有自我特异性潜力的发育中的细胞发出信号，要么编辑它们的受体，要么进行凋亡。C-Abl是Abelson小鼠白血病病毒(A-MuLV)转化基因v-Abl的细胞同源基因，可引起小鼠急性B细胞白血病。在人类中，c-Abl参与了一种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检验关于Abl激酶在B细胞发育中的生物学功能及其在转化中的作用的假说。首先，我们将进行实验，旨在了解v-Abl如何扰乱信号通路，阻止分化，并防止白血病小鼠Pro-B细胞系的凋亡。这些实验将使用一种新可用的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，称为CPR。其次，我们将测试关于c-Abl在正常小鼠B细胞发育过程中对细胞增殖、活力、基因表达、Pre-BCR信号、等位基因排斥、受体编辑和克隆性缺失的调控作用的假设。我们将尝试确定参与这些过程的Abl激酶的关键靶点。这些实验将利用原代细胞培养系统和STI-571，以及ARG(Abl相关基因)和c-Abl的可用零突变。这些研究具有重要意义，因为c-Abl参与了人类慢性粒细胞白血病和急性淋巴细胞白血病的发病机制，而且Abl抑制剂STI-571在各种恶性肿瘤的临床治疗中的应用越来越多。

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.