TISSUE SPECIFIC TUMOR INDUCTION BY POLYOMAVIRUS

多瘤病毒通常在其体内建立一种沉默的、持续的感染 自然宿主，小鼠，但在实验条件下可引起 广泛的裂解感染和诱发多达12种不同的肿瘤 组织，包括胸腺组织、唾液中的高发肿瘤 腺体和乳腺。尽管对这种病毒进行了广泛的研究 在细胞培养中，对其与宿主细胞的相互作用知之甚少。 这只动物。该方案中的实验旨在探索 导致肿瘤组织特异性的病毒-细胞相互作用 由多瘤病毒形成。 这项提议中的两个具体目标是基于这样的假设 与细胞因子相互作用的病毒调控序列有 负责组织特异性肿瘤的诱导。第一个目标是 确定与组织特异性有关的病毒基因决定因素 通过评估包含以下内容的病毒的肿瘤轮廓来研究肿瘤的发生 潜在调控序列的突变。这些监管区域 包括在原点的早期侧的序列的4Obp重复 我们之前已经展示过的复制对于 胸腺上皮瘤的诱导，以及多瘤增强子序列 对细胞培养系统中的病毒调节很重要。我们的第二个 目标是使用这些调控序列来识别和表征 结合它们的细胞因子。DNA结合蛋白将是 通过凝胶移动和足迹实验进行鉴定，并进一步 通过UV交联实验和亲和层析对其进行了表征。 多瘤病毒基因的表达和复制以及致癌作用 由病毒触发的通路，利用的是 通常参与信号转导和细胞生长控制，并且 在许多非病毒病因的癌症中都会发生改变。因此，理解 多瘤病毒诱导肿瘤的分子水平及鉴定 组织中涉及的顺式作用序列和细胞因子 肿瘤形成的特异性将提供与 细胞生长控制和癌症领域。

Polyomavirus normally establishes a silent, persistent infection in its natural host, the mouse, but under experimental conditions can cause widespread lytic infection and induce tumors in up to a dozen different tissues, including a high frequency of tumors in thymic tissue, salivary glands and mammary glands. Although the virus has been studied extensively in cell culture, little is known about its interaction with host cells in the animal. The experiments in this proposal are designed to explore the virus-cell interactions that result in tissue specificity of tumor formation by polyomavirus. The two specific aims in this proposal are based on the hypothesis that viral regulatory sequences interacting with cellular factors are responsible for tissue specific tumor induction. The first goal is to define the viral genetic determinants responsible for tissue specific tumorigenesis by evaluating the tumor profile of viruses containing mutations in potential regulatory sequences. These regulatory regions include a 4Obp duplication of sequences on the early side of the origin of replication that we have previously shown to be necessary for the induction of thymic epitheliomas, and the polyoma enhancer sequences that are important for virus regulation in cell culture systems. Our second goal is to use these regulatory sequences to identify and characterize the cellular factors that bind to them. The DNA binding proteins will be identified by gel shift and footprinting experiments and further characterized by UV crosslinking experiments and affinity chromatography. Polyomavirus gene expression and replication, as well as the oncogenic pathways triggered by the virus, utilize cellular factors that are normally involved in signal transduction and cell growth control, and that are altered in many cancers of non-viral etiology. Thus, understanding tumor induction by polyomavirus at the molecular level and identifying cis-acting sequences and cellular factors involved in the tissue specificity of tumor formation will provide new information relevant to the fields of cell growth control and cancer.