Investigation and functional characterization of new drivers of mesenchymal tumorigenesis.

摘要 未分化肉瘤是最具侵袭性的肉瘤类型，通常是转移性的， 预后。尽管已证实未分化肉瘤起源于间充质干细胞 细胞(MSCs)，有限的遗传和分子分析，以及缺乏可靠的体内模型 使临床前试验成为可能是目前尚未开发出有效疗法的主要原因 发生了。为了填补这一空白，我们最近开发了一种新的基于体外/体内间充质干细胞的遗传平台 旨在发现导致成人间充质干细胞肿瘤发生的分子驱动因素，并在临床前进行测试 环境，新的潜在的可用药途径。使用这个遗传平台进行的初步筛查，已经 揭示了精灵宝可梦(Zbtb7a)作为间叶性肿瘤抑制因子的新功能 蛋白介导的癌基因Sox9和Dlk1的抑制。此外，该平台首次亮相 除了蛋白质外，CircRNAs还可能导致间叶性肿瘤的时间。我们发现 来源于Zbtb7a基因的CircRNA(CircPOK)作为原癌基因在乳腺癌中发挥着积极的作用。 间充质肿瘤发生的过程中，我们还发现异常融合环状RNA(f-RNAs)。 CircRNAs)可以来自肉瘤相关的染色体易位。这些新的发现进一步增加了 癌症生物学中的一层复杂性，揭示了新的可能的基因内调控网络 对病理条件感到不安，并指出有必要研究其他CircRNA是否以及如何受到影响 参与了肉瘤的发生。 综合我们最近的结果和我们之前开发的遗传平台，我们现在提出：i) 对间充质肿瘤的遗传和分子驱动因素进行广泛的分析，包括 编码基因，CircRNAs和f-CircRNAs，ii)分析这些基因指导的分子作用机制 驱动因素，以及iii)确定治愈间充质肿瘤的新疗法。据此，我们提出如下建议 目的：鉴定新的蛋白质编码基因(目的1)，鉴定CircRNAs(目的2)和鉴定 驱动间充质肿瘤发生的F-CircRNAs(Aim 3)。 在K99阶段，我将获得开始我独立职业生涯所需的技能。在这个阶段，我将 开发鉴定CircRNAs和f-CircRNAs功能的分析方法和方案，然后 在R00阶段使用。此外，在K99阶段，我将进行筛选分析，特别是 对潜在的新的可药物机制感兴趣。筛选产生的候选基因将在那时 在R00阶段进行了仔细的分析。在K99阶段进行的工作将是 下一个R00阶段。因此，指导将是K99阶段的必要要素，以实现 扎实有效的结果。

ABSTRACT Undifferentiated sarcomas are the most aggressive types of sarcoma, often metastatic, with a very poor prognosis. Although it has been established that undifferentiated sarcomas originate from Mesenchymal Stem Cells (MSCs), limited genetic and molecular analyses, along with the absence of faithful in vivo models enabling pre-clinical testing are the main reasons why the development of effective therapies has not yet occurred. To fill this void, we have recently developed a novel ex vivo/in vivo MSCs-based genetic platform aimed at discovering the molecular drivers responsible for adult MSC tumorigenesis, and to test, in pre-clinical settings, new potential druggable pathways. An initial screening performed by using this genetic-platform, has revealed a new function for Pokemon (Zbtb7a) as an oncosuppressor in mesenchymal tumors through the protein-mediated repression of the oncogenes Sox9 and Dlk1. Furthermore, the platform revealed for the first time that circRNAs, in addition to proteins, can be responsible for mesenchymal tumors. We discovered that the circRNA that derives from the Zbtb7a gene (circPOK) plays an active role as a proto-oncogene in the process of mesenchymal tumorigenesis, and moreover we discovered that aberrant fusion-circRNAs (f- circRNAs) can derive from sarcoma-associated chromosomal translocations. These new findings add a further layer of complexity in the biology of cancer, revealing new possible intragenic regulatory networks that can be perturbed in pathological conditions, and point to the necessity to investigate if, and how, other circRNAs are involved in sarcomagenesis. Taking together our recent results and our previously developed genetic platform, we now propose: i) to perform a wide-ranging analysis of genetic and molecular drivers of mesenchymal tumors, encompassing coding-genes, circRNAs, and f-circRNAs, ii) to analyze the molecular mechanisms of action directed by these drivers, and iii) to identify new therapies to cure mesenchymal tumors. Accordingly we propose the following aims: Identification of new protein-coding genes (Aim 1), identification of circRNAs (Aim 2) and identification of f-circRNAs (Aim 3) that drive mesenchymal tumorigenesis. During the K99 phase, I will obtain the skills required to begin my independent career. In this phase, I will develop assays and protocols to characterize the functions of circRNAs and f-circRNAs, which will be then used during the R00 phase. Moreover in the K99 phase, I will perform a screening analysis, with a particular interest to potential new druggable mechanisms. Candidate genes resulting from the screening will be then closely analyzed during the R00 phase. The work performed during the K99 phase will be the groundwork for the next R00 phase. As such, the mentoring will be necessary element of the K99 phase in order to achieve solid and valid results.