Alternative splicing and epithelial-mesenchymal plasticity in prostate tumors

在上皮细胞中选择性剪接成纤维细胞生长因子受体-2(FGFR2)转录本 导致FGFR2(IIIb)异构体的表达，而在间充质细胞中则是同样的过程 结果合成了含有外显子IIIc的FGFR2(IIIc)。这种受调控的剪接被打乱 前列腺癌进展过程中FGFR2的异常表达 异构体。为了观察FGFR2外显子IIIc在同基因大鼠AT3肿瘤中的作用 构建了报告选择性剪接的微型基因结构。想象这些可选的剪接 结果显示，在这些原发肿瘤中发生了意想不到的间充质-上皮转化(MET)。 对这种由剪接差异揭示的上皮-间充质可塑性的理解是 此应用程序的首要目标。 为此，我们建议实现以下具体目标：具体目标1至 FGFR2剪接与上皮-间充质可塑性的关系 在前列腺癌中。我们开发了一种新的双色记者，可以用来检测这两种情况 MET和上皮-间充质转化(EMT)。我们还将我们的观察范围扩大到Well 表征了培养中的人前列腺肿瘤细胞。在这一目标中完成的工作将考验 上皮可塑性是侵袭性前列腺癌的一般特征的假说 人类。特指目的2.研究原发卵巢上皮-间充质可塑性 由剪接变化显示的前列腺癌。在这个目标中，我们将描述分子的特征 原发肿瘤中MET簇的特征和行为。具体目标3.确定 上皮-间充质可塑性与转移行为的关系。我们会 研究上皮-间充质可塑性与转移行为之间的关系。 最后，我们将从AT3大鼠肿瘤和患者中分离循环中的前列腺癌细胞，并 我们将确定它们的FGFR2剪接状态和它们的上皮状态。有的放矢地完成工作 第二，在这个目标中，将检验上皮-间充质可塑性导致 肿瘤适合度。 这项工作的意义是双重的：首先，我们将揭开关于基因的基本信息 前列腺癌进展过程中选择性剪接调控的表达程序。第二， 前列腺癌作为一种健康问题的严重性凸显了它对人类健康的潜在意义。 有问题。识别将进展为转移性疾病的肿瘤/细胞是一项挑战和 优先考虑。这里提出的工作应该识别有用的标志物，甚至可能是治疗性的 目标。

In epithelial cells alternative splicing of fibroblast growth factor receptor-2 (FGFR2) transcripts leads to the expression of the FGFR2(IIIb) isoform, whereas in mesenchymal cells the same process results in the synthesis of FGFR2(IIIc), which include exon IIIc. This regulated splicing is disrupted during progression of prostate carcinomas leading to the inappropriate expression of FGFR2 isoforms. To visualize the use of FGFR2 exon IIIc in Dunning AT3 tumors in syngeneic rats we constructed minigene constructs that report on alternative splicing. Imaging these alternative splicing decisions revealed unexpected mesenchymal-epithelial transitions (MET) in these primary tumors. The understanding of this epithelial-mesenchymal plasticity, revealed by differences in splicing, is the overarching goal of this application. To this end we propose to accomplish the following specific aims: Specific Aim 1. To characterize the connections between FGFR2 splicing and epithelial-mesenchymal plasticity in prostate tumors. We have developed a new bichromatic reporter that can be used to detect both MET and epithelial-mesenchymal transitions (EMT). We have also extended our observations to well characterized human prostate tumor cells in culture. Work accomplished in this aim will test the hypothesis that epithelial plasticity is a general property of aggressive prostate carcinomas in humans. Specific Aim 2. To characterize the epithelial-mesenchymal plasticity in primary prostate tumors revealed by alterations in splicing. In this aim we will characterize the molecular signatures and behavior of the MET clusters in primary tumors. Specific aim 3. To characterize the connections between epithelial-mesenchymal plasticity and metastatic behavior. We will investigate the connections between epithelial-mesenchymal plasticity and metastatic behavior. Finally, we will isolate circulating prostate tumor cells from both the AT3 rat tumors and patients, and we will determine their FGFR2 splicing status and their epithelial state. Work accomplished in aim two and in this aim will test the hypothesis that epithelial-mesenchymal plasticity leads to increased tumor fitness. The significance of this work is twofold: First we will unravel basic information about gene expression programs controlled by alternative splicing during prostate tumor progression. Second, the potential significance to human health is underscored by the magnitude of prostate cancer as a health problem. Identifying the tumors/cells that will progress to metastatic disease is a challenge and a priority. The work proposed here should identify useful markers and perhaps even therapeutic targets.