B61 FUNCTION DURING VASCULAR DEVELOPMENT

描述：(申请人描述) 肿瘤的渐进性生长依赖于新的 血管形成。相当多的证据表明 受体-蛋白酪氨酸激酶(R-PTKs)及其配体具有重要的 内皮细胞及其后续分化中的作用 组织进入血管系统。携带突变的“基因敲除小鼠” 在内皮细胞特异性的R-PTK及其配体中，如Flk-1，Flt-1， Tie-2和血管内皮生长因子导致血管异常导致胚胎死亡 发展。有趣的是，每个基因的突变都会导致不同的 表型异常。这些数据表明，多个信号 每条路径都有不重叠的功能，需要详细说明 脉管系统的。重要的是要确定和描述其他 有助于内皮细胞发育的基因座，以定义 血管生成和血管生成需要多种途径。B61年， ECK R-PTK的主要配体已被证明具有血管生成和 内皮细胞引诱活性。与这一概念相一致的是，B61 在小鼠胚胎发育过程中的血管形成部位表达。 这些数据提出了一个耐人寻味的可能性，即B61在 在发育中的血管系统中重新招募内皮细胞 胚胎发生与伤口愈合和肿瘤血管生成等过程 成年动物。为了验证这一假设，在胚胎干细胞中进行基因打靶 (ES)细胞将用于产生B61基因敲除小鼠。纯合子突变体 将对胚胎进行内皮细胞和血管缺陷的分析 发展。第二，B61/ECK信号通路在成人中的作用 动物将使用三种活体测试进行评估。B61和Check基因敲除 小鼠(前提是B61突变小鼠是活的；ECK突变小鼠是活的) 将测试伤口愈合能力和肿瘤生长的程度 致癌物皮肤治疗诱发肿瘤发生。此外，ES细胞 确定的B61和Ek基因类型(例如，B61-/-和/或Ek-/-细胞系) 将被测试形成血管化畸胎癌的能力 皮下注射野生型、B61突变型或EK突变型宿主。它 预计这些数据将提供对 B61/ECK信号通路在胚胎发育和血管发育中的作用 肿瘤发生学。未来，拟议的调查将有助于 确定B61和EK分子是否可以作为治疗的靶点。

DESCRIPTION: (Applicant's Description) Progressive growth of tumors is dependent on continuous stimulation of new blood vessel formation. Considerable evidence indicates that receptor-protein tyrosine kinases (R-PTKs) and their ligands have crucial roles in the differentiation of endothelial cells and their subsequent organization into the vascular system. "Knockout mice" carrying mutations in endothelial cell specific R-PTKs and ligands, such as flk-1, flt-1, tie-2, and VEGF, result in embryonic lethality due to aberrant vascular development. Interestingly, mutations in each gene gives rise to distinct phenotypic abnormalities. These data indicate that multiple signaling pathways, each with non-overlapping functions, are required for elaboration of the vasculature. It will be essential to identify and characterize other loci that contribute to endothelial cell development in order to define the multiple pathways required for vasculogenesis and angiogenesis. B61, the major ligand for the ECK R-PTK, has been shown to possess angiogenic and endothelial cell attractant activity. Consistent with this notion, B61 is expressed at sites of blood vessel formation during mouse embryogenesis. These data raise the intriguing possibility that B61 has a role in recruiting endothelial cells into the developing vasculature during embryogenesis and processes such as wound healing and tumor angiogenesis in the adult animal. To test this hypothesis, gene targeting in embryonic stem (ES) cells will be used to generate B61 knockout mice. Homozygous mutant embryos will be analyzed for defects in endothelial cell and blood vessel development. Second, the role of the B61/eck signaling pathway in adult animals will be assessed using three in vivo assays. B61 and eck knockout mice (providing that B61 mutant mice are viable; eck mutant mice are viable) will tested for wound healing capability and extent of tumor growth and tumorigenesis induced by carcinogen skin treatment. In addition, ES cells of defined B61 and eck genotypes (e.g., B61 -/- and/or eck -/- cell lines) will be tested for the ability to form vascularized teratocarcinomas after subcutaneous injection into wild type, B61 mutant, or eck mutant hosts. It is anticipated that these data will provide insight into the function of the B61/eck signaling pathway in vascular development during embryogenesis and tumorigenesis. In the future, the proposed investigations will help to determine whether B61 and eck molecules can be targeted for therapy.