Role of FACT in ZFTA-RelA fusion driven ependymoma

项目摘要/摘要 室管膜瘤是发生在大脑或脊髓的肿瘤，在近一半的患者中是无法治愈的。 最近的分子分类发现了许多室管膜瘤的分子亚群 幕上室管膜瘤ZFTA-relA融合阳性(ZFTA-relA)占70%以上 幕上室管膜瘤。ZFTA-rela是一种主要为儿科的脑瘤，也被确认为 预后最差的亚组。这些肿瘤是由中枢基因之间的致癌融合引起的。 在核因子-κB途径中，RELA和一个功能未知的基因ZFTA。由此产生的融合蛋白ZRfus， 异常招募转录和染色质重塑机制来驱动肿瘤转录 程序包括对NF-κB信号的结构性激活、对炎症基因表达的激活 计划和干细胞计划。到目前为止，化疗还没有成为任何一种 室管膜瘤的亚型。在室管膜瘤临床试验中测试的所有靶向治疗都失败了。因此， 迫切需要利用最近对ZFTA-relA的分子理解来开发 新的治疗模式，提高这些患者的生存结果。在寻找共同监管方面 蛋白质作为候选的肿瘤依赖性和靶点，我们确定了染色质重塑复合体，事实 (促进染色质转录)，作为ZRfus相互作用蛋白。此外，事实在ZFTA-RELA中被提升 与正常脑组织和其他室管膜瘤疾病亚型比较。项目目标：彻底 调查事实作为ZFTA-RELA的驱动因素，并揭示它作为这一毁灭性疾病的有希望的治疗靶点 疾病。事实上，SPT16和SSRP1是一种异源二聚体，主要用于重组核小体以促进RNA 聚合酶II介导的转录。在肿瘤方面，我们和其他人已经证明了这一事实对于 维持肿瘤生长所必需的未分化的干细胞状态。这与ZFTA-Rela相关 肿瘤，因为它们的特征是具有未分化的转录特征。项目假设：事实 调节ZRfus致癌和炎症基因，以维持未分化的细胞状态。妥协 FACT的功能将导致减少肿瘤生长，调节肿瘤炎症，并提高存活率 小鼠原位肿瘤模型。目标1：确定事实是否是维持ZRfus转录的关键 靶基因(包括癌基因和炎症基因)和干细胞识别基因，这些基因可能对 致瘤性。影响：这些研究将揭示FACT如何调节ZRfus转录和肿瘤细胞特性。 目的2：评估FACT的遗传和药物干扰对肿瘤进展、免疫功能的影响 景观、总体存活率和正常神经发生。影响：这些研究将揭示临床前对 作为治疗靶点的事实，以及我们候选的小分子抗肿瘤药物的有效性作为理论基础 治疗为未来的临床试验设计提供信息。总体而言，成功完成我们的研究将揭示出新的 ZFTA-rela室管膜瘤的治疗选择可以迅速进入临床试验。

PROJECT SUMMARY / ABSTRACT Ependymomas are tumors that occur in the brain or spinal cord and are incurable in nearly half of all patients. Recent molecular classification has identified numerous molecular subgroups of ependymoma with supratentorial ependymoma ZFTA-RELA fusion positive (ZFTA-RELA) accounting for over 70% of all supratentorial ependymomas. ZFTA-RELA, a mainly pediatric brain tumor, has also been identified as one of the subgroups with the worst prognosis. These tumors arise from the oncogenic fusion between a central gene in the NF-κB pathway, RELA, and a gene with undescribed function, ZFTA. The resulting fusion protein, ZRfus, aberrantly recruits transcriptional and chromatin remodeling machinery to drive neoplastic transcriptional programs that includes constitutive activation of NF-κB signaling, activation of inflammatory gene expression programs, and stem cell programs. To date, chemotherapy has not become standard of care for any of the subtypes of ependymoma. All targeted therapies tested in ependymoma clinical trials have failed. Therefore, there is an urgent need to capitalize on the more recent molecular understanding of ZFTA-RELA to develop novel therapeutic paradigms that increase survival outcomes for these patients. In the search for co-regulatory proteins as candidate tumor dependencies and targets, we identified the chromatin remodeling complex, FACT (FAcilitates Chromatin Transcription), as a ZRfus interacting protein. Moreover, FACT is elevated in ZFTA-RELA compared to normal brain tissue and other ependymoma disease subtypes. Project goal: To thoroughly investigate FACT as a driver of ZFTA-RELA and to reveal it as a promising therapeutic target for this devastating disease. FACT, a heterodimer of SPT16 and SSRP1, mainly serves to reorganize nucleosomes to facilitate RNA polymerase II-mediated transcription. In tumors, we and others have shown that FACT is essential for maintaining an undifferentiated stem-like state necessary for tumor growth. This is relevant for ZFTA-RELA tumors as they are characterized as having undifferentiated transcriptional profiles. Project hypothesis: FACT regulates ZRfus oncogenic and inflammatory genes to maintain an undifferentiated cell state. Compromising FACT function will lead to reduced tumor growth, modulate tumor inflammation, and improve survival in orthotopic murine tumor models. Aim 1: Determine if FACT is essential for sustaining transcription of ZRfus targets (including oncogenes and inflammatory genes) and stem cell identity genes that may be important for tumorigenicity. Impact: These studies will reveal how FACT regulates ZRfus transcription and tumor cell identity. Aim 2: Evaluate the impact of genetic and pharmacological disruption of FACT on tumor progression, immune landscape, overall survival, and normal neurogenesis. Impact: These studies will reveal preclinical insight into FACT as a therapeutic target, and the efficacy of our candidate small molecule anti-neoplastic as rationale therapy to inform future clinical trial design. Overall, successful completion of our studies will reveal new therapeutic options for ZFTA-RELA ependymoma that can rapidly be moved into clinical trials.