Characterizing an alternatively spliced NTRK2 isoform in development and cancer

项目摘要/摘要 长期以来，发育信号与癌症的启动、维持和转移之间的联系一直是 因WNT、Hedgehog和Notch路径的几个成员而闻名。可能性仍然是一个 发育调节的剪接事件可能与这些致癌途径有相似的特征，驱动 在解剖学上适当的、有时间限制的情况下的正常发育，并在以下情况下导致癌症 监管不力。我们最近发现了一种缺乏激酶的NTRK2神经营养因子受体剪接变异体， TrkB.T1在胶质瘤中占主导地位，并放大了几个致癌信号通路。我们的初步数据 提示TrkB.T1是胚胎发育过程中在多个器官中主要表达的NTRK2亚型 在人类的各种癌症类型中高度表达，当过度表达时结合起来 随着PTEN的丢失，会在小鼠中引起广泛的癌症。这里提出的项目旨在描述 利用一种新的抗体和一种新的小鼠模型显示TrkB.T1在发育和癌症中的作用 当剪接变体出生后在表达它们的特定器官中过度表达时，就是致癌的。 在开发过程中。通过干扰细胞特异性TrkB.T1剪接变体在小鼠中的表达，胚胎和 利用单细胞组合索引RNA测序分析跟踪NTRK2转录本在胚胎中的表达 和出生后发育，我的目标是(1)将发育机制和剪接选择与癌症联系起来，(2)将 一种信号增加的蛋白，以及(3)试图辨别是否将细胞困在一个特定的 发育状态会导致癌症。通过进一步描述TrkB.T1发挥作用的机制， 这些项目有可能为多种癌症的诊断和治疗开辟新的途径。 类型。这里提出的实验建立在我之前在神经发育、神经营养因子生物学、 和癌症，并将有助于为我的长期职业目标奠定基础，这些目标的中心是雇用一名 研究神经营养对肿瘤生物学的贡献和发现的发展指导方法 发育对肿瘤发生的影响。

Project Summary/Abstract The link between developmental signaling and cancer initiation, maintenance and metastasis has long been known for several members of the Wnt, Hedgehog, and Notch pathways. The possibility remains that a developmentally-regulated splicing event may share similar features with these oncogenic pathways, driving normal development in an anatomically appropriate, temporally restricted context, and causing cancer when dysregulated. We have recently shown that a kinase-deficient NTRK2 neurotrophin receptor splice variant, TrkB.T1, predominates in glioma and amplifies several oncogenic signaling pathways. Our preliminary data suggest that TrkB.T1 is the predominate NTRK2 isoform expressed across multiple organs during embryonic development, is highly expressed in various cancer types in humans, and when over-expressed in combination with PTEN loss, causes a wide range of cancers in mice. The project proposed here seeks to characterize the role TrkB.T1 in development and cancer using a novel antibody and a novel mouse model to show that specific splice variants are oncogenic when overexpressed, postnatally, in the specific organs that expressed them during development. By perturbing cell-specific TrkB.T1 splice variant expression in mice, embryonically, and using single cell combinatorial indexing RNA-sequencing analysis to follow NTRK2 transcripts across embryonic and postnatal development, I aim to (1) link developmental mechanisms and splicing choices to cancer, (2) link a kinase deficient protein with increases in signaling, and (3) seek to discern whether trapping cells in a particular developmental state can lead to cancer. By further characterizing the mechanism by which TrkB.T1 functions, these projects have the potential to open new avenues for diagnostic and therapeutic targets for multiple cancer types. The experiments proposed here build upon my previous work in neurodevelopment, neurotrophin biology, and cancer and will help set the stage for my long-term career goals which center around employing a developmentally guided approach to studying neurotrophic contributions to tumor biology and uncovering developmental influences on oncogenesis.