EXPLORE AND TARGET THE EPIGENETIC VULNERABILITY OF PAX3-FOXO1-DRIVEN RHABDOMYOSARCOMA

摘要 驱动肿瘤发生的基因异常通常与表观遗传改变相结合，例如 组蛋白甲基转移酶和组蛋白赖氨酸失控引起的组蛋白赖氨酸异常甲基化 去甲基酶(KDM)。我们的长期目标是研究致癌机制 转录因子“劫持”KDM在肿瘤发生和疾病进展中，并开发新的治疗方法 通过靶向KDM来阻断这些癌蛋白的功能。横纹肌肉瘤是一种 在儿童和青春期年轻人中发生毁灭性的软组织癌。肺泡RMS(ARMS)是一种 侵袭性更强的亚型，转移率更高。手臂主要是由病原体驱动的 融合癌蛋白PAX3-FOXO1或其变异体PAX7-FOXO1通过染色体易位 T(2；13)(q35；q14)或t(1；13)(p36；q14)。尽管目前的治疗方式已经稳定地 改善低风险RMS患者的存活率，融合阳性ARMS患者的预后 转移仍然令人沮丧。即使对于结果良好的患者，积极的化疗和 放射治疗可能导致长期的不良反应，因为儿童可能特别容易受到长期的 毒性。这些临床挑战突显了确定新的治疗靶点和 为这些患者开发更好的治疗方法。然而，有一个障碍却鲜为人知。 通过PAX3-FOXO1转化的细胞中出现的漏洞，可以用于治疗。在……里面 在这一应用中，我们将研究KDM4在PAX3-驱动的肿瘤发生中的功能影响。 Foxo1(Aim 1)；剖析KDM4抑制PAX3-FOXO1驱动臂的分子机制(Aim 2)，并将KDM4抑制剂转化为治疗PAX3-FOXO1阳性手臂的新方法(AIM 3)。这项创新的研究集成了多种方法来识别和验证新的治疗靶点 并探索小分子在由一种由基因驱动的疾病的背景下双重抑制癌蛋白 无法下药的融合癌蛋白。拟议的研究将产生影响，因为它的翻译相关性 高危RMS儿童的治疗，有可能为分子生物学提供新的线索 PAX3-FOXO1驱动臂的机理。

ABSTRACT The genetic abnormalities that drive tumorigenesis are usually coupled with epigenetic alterations such as aberrant histone lysine methylations due to deregulation of histone methyltransferases and histone lysine demethylases(KDMs). Our long-term goal is to investigate the mechanism by which oncogenic transcription factors “hijack” KDMs in tumorigenesis and disease progression, and develop new therapies to block the functions of these oncoproteins by targeting KDMs. Rhabdomyosarcoma (RMS) is a devastating soft tissue cancer in children and adolescent young adults. The alveolar RMS (aRMS) is a more aggressive subtype, with a higher rate of metastasis. aRMS is primarily driven by the pathognomonic fusion oncoprotein PAX3-FOXO1 or its variant PAX7-FOXO1 through chromosomal translocations of t(2;13)(q35;q14) or t(1;13)(p36;q14). Despite the fact that current treatment modalities have steadily improved survival of low-risk RMS patients, the outcome for the fusion positive aRMS patients with metastasis remains dismal. Even for patients with favorable outcomes, the aggressive chemotherapy and radiotherapy may lead to long-term adverse effects as children may be particularly vulnerable to long-term toxicity. These clinical challenges underscore a pressing need to identify new therapeutic targets and develop better therapies for these patients. However, one obstacle is much less is known about vulnerabilities that arise in transformed cells by PAX3-FOXO1 that could be exploited therapeutically. In this application, we will investigate the functional impact of KDM4 in tumorigenesis driven by PAX3- FOXO1 (Aim 1); dissect the molecular mechanism of KDM4 inhibition on PAX3-FOXO1-driven aRMS (Aim 2), and translate KDM4 inhibitors into novel therapeutic approaches for PAX3-FOXO1 positive aRMS (Aim 3). This innovative study integrates multiple approaches to identify and validate new therapeutic targets and explore small molecules to dually inhibit oncoproteins in the context of a disease that is driven by a undruggable fusion oncoprotein. The proposed research will be impactful for its translational relevance for the treatment of children with high-risk RMS and have the potential to shed new light on the molecular mechanism of PAX3-FOXO1-driven aRMS.