DISSECTING THE ROLES OF FAT1 AND NEAT1 IN SOFT TISSUE SARCOMA DEVELOPMENT AND METASTASIS USING NOVEL IN VIVO SARCOMA MODELS

软组织肉瘤(STSS)是一种罕见的异质性间充质肿瘤，有超过75种亚型。STS是 对肿瘤研究不足，建立的研究模型很少，缺乏资金来源。几十年来， STSS的治疗策略几乎没有改善，这些策略通常对当前的治疗方法具有抵抗力 而且经常是致命的，因为50%的患者会出现远处器官转移。为了解决这一未解决的临床问题， 准确概括这一癌症谱的体内模型为研究提供了一个独特而有效的平台 肉瘤生物学和临床前试验在新的治疗策略转化为有限的肉瘤人群之前 病人。然而，现有的体内肉瘤模型很少，因为肿瘤抑制因子和致癌因子 肉瘤发展和转移的驱动因素仍不清楚。因此，我进行了全基因组的体外遗传 筛选和直接体内CRISPR/Cas9基因敲除筛选野生型小鼠以确定其突变的驱动基因 是启动肉瘤所必需的。从这些屏幕上，我产生了一个新的体内肉瘤模型，由突变驱动 在人类STSS中频繁突变的Fat1。这是一个全新的活体模型，概括了人类的一个子集 据我们所知，首次确定Fat1在人类STSS中是一种有效的肿瘤抑制因子。此外， 利用体内肉瘤模型和高通量rna测序，我还鉴定了长的非编码rna(Lncrna)。 Neat1作为肉瘤转移的致癌驱动因子。这个K22奖项将让我建立自己的研究平台，以 进一步研究肉瘤发生和转移中的关键信号通路和靶基因 独特的体内肉瘤模型。在特定的目标1中，我们将剖析河马通路和它们的 效应器YAP1/Taz通过Fat1的突变驱动肉瘤。此外，我们将使用我的小说体内肉瘤 测试和优化抑制肉瘤肿瘤生长的最佳联合治疗策略的模型。具体而言 目的2，我们将确定lncRNA Neat1驱动肉瘤转移的机制。我的初步结果 提示RNA剪接调控基因，如Khsrp，与Neat1相互作用，促进肉瘤转移。我们会 使用我独特的体内肉瘤模型来剖析肉瘤转移的机制及其意义 这些基因用于靶向治疗转移性肉瘤患者。总而言之，完成本提案 将确定编码基因Fat1和非编码基因Neat1在 肉瘤的发展和转移，并为设计有效的靶向提供新的候选途径和基因 改善肉瘤患者预后的治疗方法。

Soft tissue sarcomas (STSs) are rare heterogeneous mesenchymal tumors that have more than 75 subtypes. STSs are understudied tumors for which there are few established research models and a lack of funding sources. Over decades, there has been little improvement in the therapeutic strategies for STSs, which are often resistant to current therapies and can be frequently fatal as 50% of patients develop metastasis in distant organs. To solve this unmet clinical problem, in vivo models that accurately recapitulate this spectrum of cancers provide a unique and effective platform for studying sarcoma biology and preclinical trials before novel therapeutic strategies translate to limited population of sarcoma patients. However, there are very few in vivo sarcoma models available because the tumor suppressor and oncogenic drivers for sarcoma development and metastasis remain unknown. Therefore, I performed genome-wide in vitro genetic screens and direct in vivo CRISPR/Cas9 knockout screens in wild type mice to identify driver genes whose mutation is required for sarcoma initiation. From these screens, I generate a novel in vivo sarcoma model driven by the mutation of Fat1 which is frequently mutated in human STSs. This is a de novo in vivo model that recapitulates a subset of human STSs and, to our knowledge, the first determination that Fat1 is a potent tumor suppressor in human STSs. Furthermore, using in vivo sarcoma models and high throughput RNA sequencing, I also identified the long non-coding RNA (lncRNA) Neat1 as an oncogenic driver for sarcoma metastasis. This K22 award will allow me to build my own research platform to further characterize the critical signaling pathways and target genes in sarcoma development and metastasis using these unique in vivo sarcoma models. In Specific Aim 1, we will dissect the mechanism by which the Hippo pathways and their effectors Yap1/Taz drive sarcomas through the mutation of Fat1. In addition, we will use my novel in vivo sarcoma models to test and optimize the best combination treatment strategies that suppress sarcoma tumor growth. In Specific Aim 2, we will determine the mechanisms by which lncRNA Neat1 drives sarcoma metastasis. My preliminary results suggest that RNA splicing regulating genes, such as Khsrp, interact with Neat1 and promote sarcoma metastasis. We will use my unique in vivo sarcoma models to dissect the mechanisms governing sarcoma metastasis and the implications of these genes for targeted therapies in treating metastatic sarcoma patients. In conclusion, completion of this proposal will determine the functional consequences of expression of the coding gene Fat1 and the non-coding gene Neat1 in sarcoma development and metastasis and provide novel candidate pathways and genes for designing effective targeted therapies to improve outcomes for sarcoma patients.