Regulation of an Angiogenic Phenotype by Jagged 1

说明（由申请人提供）：Notch受体及其配体是 调节细胞命运的进化上保守的跨膜多肽 与生理和病理过程有关 如血管生成和肿瘤发生。为了理解 Jagged 1/Notch信号在这些过程中的作用，NIH 3 T3细胞的表型 用非跨膜和分泌形式的人Jagged 1稳定转染 (sJ1)发现在血管生成过程中上调。SJ1 转染子表现出转化的表型，包括细胞内的变化， 形态学，在克隆密度下存活率增加，非锚定生长 在软琼脂中，在存在FGF 1和迁移行为的改变。SJ1 细胞还能够在绒毛尿囊中引起血管生成反应， 膜测定（CAM）和将sJ 1转染的细胞植入无胸腺 小鼠产生高度血管生成的团块。sJ 1诱导的机制 这些表型变化是未知的，并通过两个特定的目标来解决 1）确定NIH 3 T3 sJ 1表型是否由 特异性Notch受体信号传导途径的激活或抑制，和2） 确定足以诱导sJ 1表型的sJ 1最小结构域 NIH 3 T3细胞。这些目标将通过表征NIH 3 T3细胞来实现 使用一种新的生物学方法稳定转染J1和Notch缺失突变体， 基于实验室的分析？sJ 1转染子的特性。 阐明sJ 1调节细胞表型的机制可能有助于 在用于治疗病理性 条件，如癌症。

DESCRIPTION (provided by applicant): Notch receptors and their ligands are evolutionarily conserved transmembrane polypeptides that regulate cell fate determination and are associated with physiological and pathological processes such as angiogenesis and tumorigenesis. In order to understand the role of Jagged 1/Notch signaling in these processes, the phenotype of NIH 3T3 cells stably transfected with a non-transmembrane and secreted form of human Jagged 1 (sJ1) found to be upregulated during angiogenesis was examined. sJ1 transfectants exhibit a transformed phenotype that includes changes in cell morphology, increased survival at clonal density, anchorage-independent growth in soft agar in the presence of FGF1 and alterations in migratory behavior. sJ1 cells are also able to elicit an angiogenic response in the chorioallantoic membrane assay (CAM) and implantation of sJ1 transfected cells into athymic mice yielded highly angiogenic masses. The mechanisms by which sJ1 induces these phenotypic changes are unknown and are addressed by the two specific aims of this proposal 1) to determine if the NIH 3T3 sJ1 phenotype results from activation or inhibition of specific Notch receptor signaling pathways and 2) to determine the minimal domain of sJ1 sufficient to induce the sJ1 phenotype in NIH 3T3 cells. These objectives will be met by characterizing NIH 3T3 cells stably transfected with J 1 and Notch deletion mutants using a novel biological assay based on the laboratory?s characterization of sJ1 transfectants. Elucidation of the mechanisms by which sJ1 regulates cellular phenotype may aid in the development of therapeutic agents used for the treatment of pathological conditions such as cancer.