Regulation of the Hedgehog pathway and Medulloblastoma response to radiochemotherapy

Hedgehog 通路的调节和髓母细胞瘤对放化疗的反应

• 批准号: 10558221
• 负责人: Huadong Pei
• 金额: $ 38.48万
• 依托单位: GEORGETOWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-15 至 2026-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10558221
• 关键词: Address; Affect; Antibodies; Biochemical; Cell physiology; Cells; Childhood Brain Neoplasm; Development; Developmental Process; Diagnosis; Disease; Ensure; Erinaceidae; FRAP1 gene; GLI gene; GLI2 gene; Genetic Transcription; Genetically Engineered Mouse; Glioma; Glucose; Goals; Growth; Homeostasis; In Vitro; Investigation; Knowledge; Laboratories; Lead; Ligands; Light; Link; Mass Spectrum Analysis; Mediating; Modeling; Modification; Molecular; Nutrient; O-GlcNAc transferase; Oncogenes; Pathway interactions; Patients; Physiology; Play; Proteins; Proteome; Proteomics; Public Health; Regulation; Research; Role; Science; Signal Transduction; Testing; Therapeutic; Work; base; biophysical techniques; cancer cell; cancer therapy; chemoradiation; design; detection method; effective therapy; experimental study; extracellular; improved; in vivo; insight; medulloblastoma; mortality; multidisciplinary; novel; novel marker; novel therapeutics; nutrition; patient derived xenograft model; personalized medicine; postnatal; response; sensor; smoothened signaling pathway; therapeutic target; transcription factor

Project Summary The Hedgehog (HH) pathway plays a pivotal role in diverse aspects of development and postnatal physiology. Perturbation of the HH pathway and activation of glioma-associated oncogene (GLI), a dedicated transcription factor in this pathway, is responsible for approximately 30% of medulloblastomas (MB), a common and aggressive type of pediatric brain tumor. Therefore, HH signaling has emerged as a therapeutic target for MB therapy. Despite the relevance of these insights to development and disease, substantial gaps still remain in our knowledge of the mechanisms involved in regulation of response to HH signaling and crosstalk with other pathways. Therefore, elucidating the molecular mechanisms of HH signaling is essential to advance our fundamental understanding of both developmental processes and HH-dependent MB. Combining a novel homemade Pan-anti-O-GlcNAc antibody with proteome-wide profiling of O-GlcNAcylated transcription factors by quantitative mass spectrometry, we identified a previously unknown mechanism by which the HH pathway is regulated by glucose-sensing O-GlcNAcylation. Specifically, the core component of the HH pathway (GLI1 and GLI2) is O-GlcNAcylated by O-GlcNAc transferase (OGT), which in turn regulates GLI transcriptional activity. Furthermore, GLI O-GlcNAcylation is regulated by HH ligands and the mTOR/S6K pathway. Importantly, both OGT and GLI O-GlcNAcylation are significantly elevated in MB. OGT inactivation renders MB cancer cells particularly sensitive to radiochemotherapy, suggesting that O-GlcNAcylation could serve as a novel potential therapeutic target for MB. Based on these preliminary findings, we hypothesize that (a) OGT-mediated GLI O- GlcNAcylation activates the HH pathway and promotes MB, and (b) dysregulation of O-GlcNAcylation could affect cancer cell sensitivity to radiochemotherapy. To test this hypothesis, in this application we propose to dissect the molecular mechanisms underlying O-GlcNAcylation-activated GLI in the HH pathway, determine how GLI O-GlcNAcylation is regulated by canonical and non-canonical HH signaling, and decipher the role of the OGT- GLI axis in MB growth in vivo. Our studies could address important questions regarding a novel role of O-GlcNAcylation in HH pathway and radiochemotherapy. Our multifaceted investigation is based on compelling premises and will be carried out with strong scientific rigor, thus promising to fill a major gap of knowledge and have a far-reaching conceptual advance in the field. From the translational perspective, elucidating the significance of O-GlcNAc dysregulation in MB could provide a novel biomarker and a potential alternative therapeutic strategy to treat patients with HH-dependent MB.

项目摘要 Hedgehog(HH)途径在发育和出生后生理的各个方面发挥着关键作用。 HH途径的扰动与胶质瘤相关癌基因(GLI)的激活 这一途径中的因子导致了大约30%的髓母细胞瘤(MB)，这是一种常见的 侵袭型儿童脑瘤。因此，HH信号已成为MB的治疗靶点 心理治疗。尽管这些见解与发展和疾病有关，但在我们的 对HH信号的反应和与其他信号的串扰的调节机制的知识 小路。因此，阐明HH信号转导的分子机制对于我们的研究具有重要意义。 对发育过程和HH依赖的MB有基本的了解。将一部小说 自制泛抗O-GlcNAc抗体与O-GlcN酰化转录因子的全蛋白质组图谱 定量质谱学，我们确定了一个以前未知的机制，HH途径是 受葡萄糖敏感的O-GlcN酰化调控。具体地说，HH途径的核心成分(GLI1和 GLI2)被O-GlcNAc转移酶(OGT)O-GlcN酰化，进而调节GLI的转录活性。 此外，GliO-GlcN酰化受HH配体和mTOR/S6K途径的调节。重要的是，两者 在MB中，OGT和GLI O-GlcN酰化显著升高。OGT失活导致MB癌细胞 对放化疗特别敏感，提示O-GlcN酰化可能是一种新的潜在的 MB的治疗靶点。基于这些初步发现，我们假设：(A)OGT介导的GLIO- GlcN酰化激活HH途径并促进MB，以及(B)O-GlcN酰化异常可能 影响癌细胞对放化疗的敏感性。为了检验这一假设，在本应用程序中，我们建议 剖析HH途径中O-GlcN酰化激活GLI的分子机制，确定如何 Gli O-GlcN酰化受规范和非规范HH信号的调节，并破译 OGT-GLI轴在MB体内的生长。我们的研究可以解决关于一个新的角色的重要问题 HH途径中的O-GlcN酰化与放化疗我们多方面的调查是基于令人信服的 并将以强大的科学严谨性进行，从而有望填补知识和技术方面的重大空白 在这一领域有深远的概念进步。从翻译的角度，阐明 O-GlcNAc异常在MB中的意义可能提供一种新的生物标志物和潜在的替代 治疗HH依赖MB患者的治疗策略。