NOVEL ONCOGENES IN VIRUS INDUCED MYELOID TUMORS

BXH-2小鼠发生髓性白血病的发病率高， 与亲嗜性鼠白血病病毒的表达相关 （MuLV）。MuLV作为插入诱变剂， 导致白血病的细胞原癌基因的表达。以来 骨髓性白血病在小鼠中是罕见的，并且100%的BXH-2小鼠发生这种情况。 白血病，BXH-2小鼠代表了一个独特的和强大的模型系统， 参与骨髓性白血病发生的基因的鉴定。我们有 证明了对病毒整合位点的分析鉴定了 新的基因座（Evi 2）参与人类以及鼠类疾病。但我们 已经表明，整合到Evi 2中只存在于10%的 肿瘤分析，表明存在其他几个位点， 靶点来自病毒整合和参与骨髓肿瘤发生。 我们最近发现了一个新的共同整合位点，Meis 1（髓样 亲嗜性病毒整合位点1），在BXH-2骨髓肿瘤。我们有 发现15%的肿瘤在Meis 1中有病毒整合， Meis 1的染色体定位表明它代表一个新的基因座。一 鉴定了侧翼为病毒整合和序列的基因 分析表明该基因是一个新的与PBX相关的同源盒基因 同源结构域家族（参与前B细胞淋巴瘤的一个成员）。 我们在本提案中的目标是描述Meis 1在以下方面的作用： 发展和白血病。此外，我们计划确定更多的 BXH-2肿瘤中病毒整合的常见位点以及开始 确定宿主BXH-2小鼠在发生髓性白血病中的作用。 这些结果不仅提供了基因类型的信息， 导致白血病，但也涉及正常的基因， 造血 该项目的具体目标是完成克隆， Meis 1基因组基因座及其编码基因的表征。到 在细菌表达载体中表达Meis 1蛋白， 针对Meis 1蛋白的多克隆抗血清。抗血清将是 用于确认Meis 1的核定位以及研究 发展性表达细菌产生的融合蛋白将 用于开始鉴定Meis 1的结合位点。Meis 1的作用 骨髓细胞发育和白血病将由 骨髓细胞系中有义和反义转录物的过表达， 小鼠骨髓。这三个目标的结果将提高我们的 了解一种新的同源框的功能和表达， 基因此外，我们计划分离病毒的其他共同位点， 整合，目的是确定 整合网站。最后，我们将探讨 BXH-2小鼠的骨髓细胞区室，以确定宿主具有什么样的作用 赋予疾病特异性。所得结果 该项目将建立在现有的基因数据库，涉及鼠 髓系白血病的发生和这些基因在人类中的潜在作用 肿瘤形成最后，这些研究将提供信息， 宿主在赋予疾病特异性方面起作用。

BXH-2 mice develop a high incidence of myeloid leukemia that is causally associated with the expression of an ecotropic murine leukemia virus (MuLV). The MuLVs are acting as insertional mutagens to alter at the expression of cellular protooncogenes that contribute to leukemia. Since myeloid leukemia is rare in mice and 100% of BXH-2 mice develop this leukemia, BXH-2 mice represent a unique and powerful model system for the identification of genes involved in myeloid leukemogenesis. We have demonstrated that the analysis of the viral integration sites identifies new loci (Evi2) involved in human as well as murine disease. However, we have shown that integrations into Evi2 are present in only 10% of the tumors analyzed, indicating that there exists several other loci that are targets from viral integration and participation in myeloid tumorigenesis. We have recently identified a nw common site of integration, Meis1 (Myeloid ecotropic viral integration site 1), in the BXH-2 myeloid tumors. We have found that 15% of the tumors have viral integrations within Meis1 and that the chromosomal location of Meis1 suggests it represents a novel locus. A gene was identified that is flanked by the viral integrations and sequence analysis reveals the gene to be a novel homeobox gene related to the PBX homeodomain family (one member which is involved in pre-B cell lymphomas). Our goals in this proposal are to characterize the role of Meis1 in development and leukemia. In addition, we plan to identify additional common sites of viral integration in the BXH-2 tumors as well as begin to identify the role of the host BXH-2 mice in developing myeloid leukemia. These results will provide information not only as to types of genes that contribute to leukemia, but also to the genes that are involved in normal hematopoiesis. The specific goals of this project are to complete the cloning and characterization of the Meis1 genomic locus and its encoded gene. To express the Meis 1 protein in a bacterial expression vector and generate polyclonal antisera against at the Meis1 protein. The antisera will be used to confirm the nuclear localization of Meis 1 as well as study the developmental expression. The bacterially generated fusion protein will be used to begin to identify the binding site of Meis1. The role of Meis1 in myeloid cell development and leukemia will be explored by the overexpression of sense and antisense transcripts in myeloid cell lines and murine bone marrow. The results of these three aims will enhance our understanding of the function and expression of a novel homeobox containing gene. In addition, we plan to isolate additional common site of viral integration, with the aim of identifying complementation groups of integration sites. Finally, we are going to explore the mechanics of the myeloid cell compartment in BXH-2 mice to determine what role the host has in conferring the disease specificity. The results obtained in this project will build on the existing database of genes involved in murine myeloid leukemogenesis and the potential role of these genes in human neoplasia. Finally, these studies will provide information as tot the role the host plays in conferring disease specificity.