The Molecular function of ecto 5' nucleotidase in fusion-negative rhabdomyosarcoma

项目摘要/摘要 横纹肌肉瘤(RMS)是一种儿童侵袭性软组织肉瘤，其特征是缺乏 肌源性分化。RMS分为两类分子：融合阳性(FP-RMS)携带 染色体平衡易位产生致癌的Pax3-FOXO1或Pax7-FOXO1蛋白，并进行融合 不包括融合事件的负值(FN-RMS)。目前对FN-RMS的治疗仍然很差， FN-RMS转移性患者的长期无事件生存率低于30%。TWIST2转录因子 通过抑制MyoD功能抑制肌肉发生，TWIST2在FN-RMS中的敲除被显示抑制 促进肿瘤细胞生长，促进肌源性分化。要了解TWIST2背后的机制 为了确定其在FN-RMS中的功能，我们试图确定其直接转录靶点。其中，我们鉴定出NT5E， 编码外显子5‘-核苷酸酶，作为TWIST2的直接靶基因。NT5E的主要作用是将腺苷- 嘌呤能信号通路中的一磷到腺苷。NT5E已被证明可促进癌症 人类黑色素瘤和乳腺癌的进展、侵袭和转移。然而，它在FN中可能扮演的角色- RMS尚未被探索。在这个方案中，我们假设NT5E与FN-RMS肿瘤的形成有关 并通过激活嘌呤能信号通路而进展。为了检验这一假设，我们将 探讨NT5E在体内外FN-RMS发病机制中的作用。然后，我们 将阐明NT5E促进FN-RMS的分子机制。这项研究计划的完成将 推动我们关于NT5E在FN-RMS发病机制中的作用的知识的界限 开发FN-RMS新的治疗策略的目标。

Project Summary/Abstract Rhabdomyosarcoma (RMS) is an aggressive pediatric soft tissue sarcoma characterized by the lack of myogenic differentiation. RMS is divided in two molecular categories: fusion positive (FP-RMS) carrying a balanced chromosomal translocation generating an oncogenic Pax3-FOXO1 or Pax7-FOXO1 protein, and fusion negative (FN-RMS) that does not include the fusion event. Current treatments for FN-RMS remain poor and the long-term event-free survival rate for FN-RMS metastatic patients is below 30%. TWIST2 transcription factor represses myogenesis by inhibiting MyoD function and knockdown of TWIST2 in FN-RMS is shown to inhibit tumor cell growth and enhance myogenic differentiation. To understand the mechanisms underlying TWIST2 function in FN-RMS, we sought to identify its direct transcriptional targets. Among them, we identified NT5E, encoding an ecto 5’-nucleotidase, as a direct target gene of TWIST2. NT5E’s main role is to convert adenosine- monophosphate to adenosine in the purinergic signaling pathway. NT5E has been shown to promote cancer progression, invasion and metastasis in human melanoma and breast cancer. However, it’s possible role in FN- RMS has not been explored. In this proposal, we hypothesize that NT5E contributes to FN-RMS tumor formation and progression through the activation of the purinergic signaling pathway. To test this hypothesis, we will investigate the contribution of NT5E expression to the pathogenesis of FN-RMS in vitro and in vivo. Then, we will delineate the molecular mechanism whereby NT5E promotes FN-RMS. Completion of this research plan will push the boundaries of our knowledge regarding the role of NT5E in FN-RMS pathogenesis with the ultimate goal of developing novel therapeutic strategies for FN-RMS.