NORMAL & NEOPLASTIC FUNCTION OF THE BCL-2 PROTO-ONCOGENE

普通的

• 批准号: 3201853
• 负责人: DONALD L EWERT
• 金额: $ 17.04万
• 依托单位: WISTAR INSTITUTE
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-08-15 至 1995-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3201853
• 关键词: B lymphocyte; Retroviridae; T lymphocyte; apoptosis; avian lymphomatosis; cell growth regulation; chickens; early embryonic stage; embryo /fetus cell /tissue; flow cytometry; gene expression; genetic library; hematopoiesis; hematopoietic stem cells; immunofluorescence technique; in situ hybridization; laboratory mouse; lymphoma; metastasis; molecular cloning; monoclonal antibody; neoplasm /cancer genetics; neoplastic growth; neoplastic transformation; northern blottings; nucleic acid hybridization; nucleic acid sequence; oncogenes; polymerase chain reaction; protooncogene; transfection /expression vector; transposon /insertion element

Activation of the putative oncogene bcl-2 is implicated as one of the causative factors in the development of B cell lymphomas in humans. However, little is known about the role of bcl-2 in the transformation process, or its involvement in the development of other types of neoplasias. Furthermore, very little is known about how bcl-2 is involved in normal embryonic development and cellular differentiation. The goal of this project is to elucidate the role of the bcl-2 gene product in neoplastic and normal cellular development. The starting point of our investigation will be our observation that overexpression of the human bcl- 2 gene is an avian retroviral vector (RCASbcl-2) results in the development of neoplasia involving a variety of tissues and multiple cell lineages in the chicken. The recently developed replication competent RCAS vectors permit expression of the bcl-2 gene in most tissues and under transcriptional control of a variety of viral promoters of different strengths. This is the first system in which the bcl-2 gene has been shown to cause neoplastic transformation, apparently, independent of the involvement of other known oncogene(s). Our first goal will be to characterize the different neoplasias with emphasis on the state of differentiation of the transformed cell, as well as that of the initial target cell of transformation. We will also examine the involvement of other oncogenes, in addition to bcl-2, that may be activated by proviral integration and be involved in the transformation process. In addition to the effect of constitutive bcl-2 deregulation on neoplastic transformation we will also examine its effect on hematopoietic cell development and function. Beginning with our observation that overexpression of bcl-2 blocks apoptosis in immature B cells in the bursa of Fabricius, we will proceed to determine what effect bcl-2 deregulation has on the differentiation and maturation of B cells as well as other lineages of hematopoietic cells. We will also analyze the effect that deregulation of bcl-2 expression has on the development and progression of B cell lymphomas that are initiated by proviral insertion in the c-myc locus. In addition to analyzing the effects of aberrant expression of bcl-2 we will examine the role of bcl-2 in normal embryonic development particularly in the differentiation and maturation of the lymphoid system. The avian system is well suited for studies of ontogeny because of the accessibility of the embryo to manipulation and particularly for the analysis of hematopoietic cell development because of the compartmentalization of the sites of B cell and T cell development in discrete organs. We will begin the studies by using the currently available human bcl-2 probes, which we have shown to cross-hybridize with the avian homologue under stringent conditions. Since the avian bcl-2 homologue has never been shown to be involved in avian lymphomagenesis in the chicken, we will clone and characterize the chicken bcl-2 gene, compare it with the human and chicken sequences and determine if the overexpressed chicken gene can also induce tumor formation.

推定的致癌基因Bcl-2的激活被认为是其中之一 人类B细胞淋巴瘤发育中的致病因素。 但是，关于Bcl-2在转换中的作用知之甚少 过程，或它参与其他类型的发展 肿瘤。 此外，关于BCL-2的涉及方式知之甚少 在正常的胚胎发育和细胞分化中。 该项目的目的是阐明Bcl-2基因产品的作用 在肿瘤和正常的细胞发育中。 我们的起点 调查将是我们观察到的人类Bcl-的过表达 2基因是禽流病毒载体（RCASBCL-2）导致发展 涉及各种组织和多个细胞谱系的肿瘤 鸡。 最近开发的复制能干的RCAS向量 允许在大多数组织和下方表达Bcl-2基因 各种不同病毒启动子的转录控制 优势。 这是显示Bcl-2基因的第一个系统 引起肿瘤转化，显然与 其他已知的癌基因的参与。 我们的第一个目标是 表征不同的肿瘤，重点是 转化的细胞的分化以及初始细胞的分化 转化的目标细胞。 我们还将研究 除Bcl-2外，其他癌基因可能会被病毒激活 集成并参与转换过程。 除了组成型Bcl-2放松管制对肿瘤的影响 转化我们还将检查其对造血细胞的影响 发展和功能。 从我们的观察开始 Bcl-2的过表达阻止了Bursa中未成熟B细胞中的凋亡 Fabricius，我们将继续确定Bcl-2放松管制的影响 具有B细胞以及其他的分化和成熟 造血细胞的谱系。 我们还将分析 Bcl-2表达的放松管制对 B细胞淋巴瘤是通过在C-MYC中插入前插入的B细胞淋巴瘤 轨迹。 除了分析Bcl-2异常表达的影响之外 将检查Bcl-2在正常胚胎发育中的作用，特别是 在淋巴系统的分化和成熟中。 鸟 系统非常适合研究，因为可访问性 操纵的胚胎，特别是用于分析 造血细胞的发育是因为 离散器官中B细胞和T细胞发育的位点。 我们将通过使用当前可用的人Bcl-2开始研究 探针，我们已证明可以与鸟类同源物交叉杂交 在严格的条件下。 由于鸟类Bcl-2同源物从未有过 证明与鸡肉中的禽淋巴作用有关，我们将克隆 并描述鸡Bcl-2基因，将其与人类和人类进行比较 鸡序，并确定过表达的鸡基因是否也可以 诱导肿瘤形成。