Imaging Vasular Tumors caused by Loss of Notch Function

哺乳动物表达四个Notch受体类似物(Notchi-4)，它们与广泛的 在胚胎发育、出生后发育和包括癌症在内的各种病理过程中发挥作用。作为一名 结果，人们对阻断或激活特定细胞中的Notch信号的疗法越来越感兴趣 或者是病态的背景。在上一个资助期内，我们探讨了引发的各种影响 通过结合敲入的Notchi等位基因(NL：：CreLo)的一种新的遗传方法使Notchi活性丧失，在 哪个Cre取代了NICD，以及一个条件Notchi靶等位基因(Niflox)。反式杂合子 动物(NL：CreLo/Flox)被培育成在分子报告核心培育的报告小鼠 分别含有甲虫红色荧光素酶和双报告基因(lac-Z或EYFP) Rosa26基因座下游的等位基因。一种系统的、终身的生物发光活体屏幕 对发生随机的、进行性的和年龄相关的Notchi丢失的动物的成像确定了一个角色 诺奇在抑制血管系统肿瘤方面的作用。我们的发现对Genetech提出了警告 针对诺奇的治疗方法，并提供了一个评估延迟、预防策略的模型 或控制血管肿瘤的形成，从而拓宽了抗Notch疗法的治疗窗口。我们 将使用新的NL：：CreERT2等位基因检查年龄、饮食和器官依赖在血管肿瘤形成中的作用 允许暂时控制诺奇的损失。我们将使用另一种新的Notch反式杂合子 组合，n2：：CreLo/FLOX，以监控特定与Notch2丢失相关的风险。一项额外的 从拟议的实验中受益的将是诺奇所在的所有干细胞隔间的详细地图 Notch2保持茎干或促进分化。这些研究最终将导致更安全的Notch- 有针对性的治疗。

Mammals express four Notch receptor paralogs (Notchi -4) that have been implicated in a broad range of functions during embryogenesis, post-natal development, and vartous pathologies, including cancer. As a result, there is growing interest in therapies aimed at blocking or activating Notch signaling in specific cellular or pathological contexts. During the previous funding period, we explored the spectrum of effects triggered by loss of Notchi activity with a novel genetic approach combining a knock-in Notchi allele (Nl ::CreLo), in which Cre replaced the NICD, and a conditional Notchi target allele (Niflox). The trans-heterozygous animals (Nl :CreLo/flox) were bred to reporter mice developed in the Molecular Reporter Core which contained floxed-stop click beetle red luciferase and dual reporter (lac-Z or eYFP) genes on respective alleles downstream ofthe ROSA26 locus. A systematic, life-long in vivo screen with bioluminescence imaging of animals wherein a random, progressive and age-dependent Notchi loss occurred identified a role for Notchi in suppressing neoplasia ofthe vascular system. Our findings caution against the Genetech approach of therapies targeting Notchi and provide a model in which to assess strategies to delay, prevent or control vascular tumor formation and thereby widen the therapeutic window of anti-Notch therapies. We will examine age, diet and organ dependence in vascular tumor formation using new Nl ::CreERT2 alleles permitting temporal control over loss of Notchi. We will use another new Notch trans-heterozygous combination, N2::CreLo/flox, to monitor risks associated specifically with loss of Notch2. An additional benefit from the proposed experiments will be a detailed map of all stem cell compartments where Notchi and Notch2 maintain stemness or promote differentiation. These studies will ultimately lead to safer Notch- targeting therapies.