Mechanisms of aggressive Rhabdomyosarcoma.

侵袭性横纹肌肉瘤的机制。

• 批准号: 10560866
• 负责人: David Michael Langenau
• 金额: $ 54万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-03-01 至 2028-02-29
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10560866
• 关键词: ATAC-seq; Accounting; Affect; Aggressive behavior; Alleles; Animal Genetics; Animal Model; Antibodies; Automobile Driving; Binding; Binding Sites; Biological; Cancer Model; Cell model; Cell surface; Cells; Cessation of life; Childhood; Childhood Soft Tissue Sarcoma; Clustered Regularly Interspaced Short Palindromic Repeats; Combined Modality Therapy; Complex; DNA Binding; Data; Development; Diagnosis; Disease; Doxycycline; Drug Targeting; Exhibits; Genes; Genetic Engineering; Genetic Transcription; Goals; Grant; Growth; Heterogeneity; Human; In Vitro; Knock-in; Knock-out; Maintenance; Malignant Neoplasms; Modeling; Molecular; Mus; Mutate; Mutation; Oncogenic; Operative Surgical Procedures; Outcome; PIK3CA gene; Pathway interactions; Patients; Pharmaceutical Preparations; Production; Prognosis; Proteins; Radiation therapy; Relapse; Reporting; Resistance; Rhabdomyosarcoma; Role; Skeletal Muscle; Specificity; Testing; Therapeutic; United States; Work; Xenograft procedure; Zebrafish; cancer stem cell; cell type; chemotherapy; innovation; malignant muscle neoplasm; multiple omics; mutant; neoplastic cell; novel; nuclease; patient derived xenograft model; programs; refractory cancer; single-cell RNA sequencing; stem cell fate; stem cell function; targeted treatment; therapeutic target; therapy resistant; transcription factor; translational impact; tumor; tumor growth

ABSTRACT Rhabdomyosarcoma (RMS) is the most common pediatric soft tissue sarcoma in the United States and displays features of skeletal muscle arrested at early stages of development. The aggressive MYOD1L122R mutated spindle/sclerosing RMS subtype accounts for 10% of pediatric diagnoses and have an extremely poor prognosis, even despite multi-modal treatment with surgery, radiation, and chemotherapy. The L122R mutation is predicted to modulate the DNA binding specificity of the Myogenic Differentiation 1 (MYOD1) transcription factor and regulates as of yet unknown transcriptional gene programs to elevate aggression and treatment resistance. To date, a detailed molecular understanding of how MYOD1L122R affects the genesis of RMS, its progression and drives therapy resistance is unknown. No cellular or molecular mechanistic studies of MYOD1L122R in RMS have been reported, no tractable genetically-engineered animal models have been developed, nor is it known if MYOD1L122R is required for continued human tumor growth or if it is rather a modifier of disease aggression, therapy resistance, or cancer stem cells (CSCs). The long-term goal and objective of our studies is to identify new molecular mechanisms and drug targets in MYOD1L122R mutant RMS that regulate aggression, therapy resistance, and CSCs. Our central hypothesis is that MYOD1L122R is a neo- morphic transcription factor that regulates pathways required for tumor maintenance and the production of therapy-resistant CSCs. The rationale and feasibility of our approach lies in our group’s recent discovery of molecularly distinct CSCs in MYOD1L122R mutant RMS, robust data showing that CSCs pathways and numbers are increased in isogenic knock-in and doxycycline-inducible MYOD1L122R RMS human cell models, and development of a new zebrafish model of MYOD1L122R-induced RMS that has elevated numbers of tumor- propagating cells. Aim 1 will assess roles for MYOD1L122R in enhancing tumor onset, growth, CSCs, and therapy resistance. Aim 1a will innovate new MYOD1L122R mutant RMS zebrafish models, testing the hypothesis that MYOD1L122R is itself not oncogenic, but drives elevated aggression only when complexed with other oncogenic drivers including activating mutations in RAS and PIK3CA. We also hypothesize that MYOD1L122R acts in part by increasing the overall fraction of tumor-propagating cells. Aim 1b will extend these findings to human RMS, testing the hypothesis that MYOD1L122R is required for continued tumor maintenance and regulates cell states including the production of therapy-resistance CSCs. Aim 2 will uncover MYOD1L122R regulated transcriptional targets, pathways, and mechanisms in RMS, testing the hypothesis that MYOD1L122R alters the DNA binding site specificity and transcriptionally regulates a novel set of genes to promote elevated RMS aggression, therapy resistance, and cancer stem cell fate. This work will have a positive translational impact by defining new pathways to kill MYOD1L122R mutant RMS, including those that target therapy-resistant CSCs, and identifying potential therapeutic targets that are likely shared across RMS subtypes.

摘要 横纹肌肉瘤（RMS）是美国最常见的儿科软组织肉瘤， 显示出骨骼肌在早期发育阶段停止的特征。具有侵略性的MYOD 1 L122 R 突变的梭形/硬化型RMS亚型占儿科诊断的10%， 即使采用手术、放疗和化疗等多模式治疗，预后也是如此。L122R 预测突变调节肌原性分化1（MYOD 1）的DNA结合特异性 转录因子，并调节未知的转录基因程序，以提高侵略性， 治疗阻力迄今为止，关于MYOD 1 L122 R如何影响MYOD 1 L122基因的发生的详细分子理解， RMS、其进展和驱动治疗抗性是未知的。没有细胞或分子机制的研究 MYOD 1 L122 R在RMS中的表达已有报道，但尚未建立易于处理的基因工程动物模型。 目前还不清楚MYOD 1 L122 R是否是人类肿瘤持续生长所必需的，或者它是否是一种肿瘤抑制剂。 疾病侵袭、治疗抗性或癌症干细胞（CSC）的修饰剂。长期目标和 我们的研究目的是确定MYOD 1 L122 R突变型RMS的新分子机制和药物靶点 调节攻击性、治疗抵抗和CSC。我们的中心假设是MYOD 1 L122 R是一个新的， 一种调节肿瘤维持和产生所需途径的形态转录因子 治疗抗性CSC。我们方法的合理性和可行性在于我们小组最近发现， MYOD 1 L122 R突变型RMS中分子上不同的CSC，稳健的数据表明， 在同基因敲入和多西环素诱导的MYOD 1 L122 R RMS人细胞模型中增加，和 开发了一种新的MYOD 1 L122 R诱导的RMS斑马鱼模型，该模型的肿瘤数量增加， 繁殖细胞目的1将评估MYOD 1 L122 R在增强肿瘤发生、生长、CSC和肿瘤生长中的作用。 治疗抵抗Aim 1a将创新新的MYOD 1 L122 R突变体RMS斑马鱼模型，测试 MYOD 1 L122 R本身不是致癌的，但只有当与MYOD 1 L122 R复合时， 其他致癌驱动因素，包括RAS和PIK 3CA中的激活突变。我们还假设， MYOD 1 L122 R部分通过增加肿瘤增殖细胞的总体分数起作用。目标1b将扩展这些 研究结果对人类RMS，测试MYOD 1 L122 R是持续肿瘤维持所需的假设 并调节细胞状态，包括治疗抗性CSC的产生。目标2将揭开MYOD 1 L122 R 调节RMS中的转录靶点、途径和机制，检验MYOD 1 L122 R 改变了DNA结合位点的特异性，并在转录上调节一组新的基因， RMS侵略性，治疗抗性和癌症干细胞命运。这项工作将有积极的翻译 通过定义新的途径杀死MYOD 1 L122 R突变型RMS，包括那些靶向治疗耐药的RMS， CSC，并确定可能在RMS亚型之间共享的潜在治疗靶点。