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: 10704616
• 负责人: Huadong Pei
• 金额: $ 37.02万
• 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/10704616
• 关键词: Address; Affect; Antibodies; Biochemical; Cell physiology; Cells; Childhood Brain Neoplasm; Dedications; 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; Ligands; Link; Mass Spectrum Analysis; Mediating; Modeling; Modification; Molecular; Nutrient; O-GlcNAc transferase; Oncogene Activation; Oncogenes; Pathway interactions; Patients; Physiology; Play; Proteins; Proteome; Proteomics; Public Health; Regulation; Research; Role; Science; Signal Transduction; Testing; Therapeutic; Work; 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）通路在发育和出生后生理的各个方面起着关键作用。 HH通路的扰动和胶质瘤相关癌基因（GLI）的激活， 在这一途径中的因子，负责大约30%的髓母细胞瘤（MB），一种常见的， 侵袭性小儿脑肿瘤因此，HH信号传导已成为MB的治疗靶点 疗法尽管这些见解与发展和疾病相关，但我们的研究仍然存在重大差距。 了解HH信号应答调节机制以及与其他细胞的串扰 途径。因此，阐明HH信号传导的分子机制对于推进我们的研究至关重要。 对发育过程和HH依赖性MB的基本理解。结合一部小说 自制泛抗-O-GlcNAc抗体与O-GlcNAc酰化转录因子的蛋白质组全谱分析 定量质谱，我们确定了一个以前未知的机制，通过该机制HH途径是 由葡萄糖敏感O-GlcNAc酰化调节。具体而言，HH途径的核心组分（GLI 1和GLI 2）是一种蛋白质。 GLI 2）被O-GlcNAc转移酶（OGT）O-GlcNAc酰化，O-GlcNAc转移酶又调节GLI转录活性。 此外，GLI O-GlcNAc酰化受HH配体和mTOR/S6 K途径调节。重要的是，两者 MB中OGT和GLI O-GlcNAc酰化显著升高。OGT失活使MB癌细胞 特别是对放射化疗敏感，这表明O-GlcNAc化可以作为一种新的潜在的 MB的治疗目标。基于这些初步发现，我们假设（a）OGT介导的GLI 0- GlcNAc酰化激活HH途径并促进MB，和（B）O-GlcNAc酰化的失调可 影响癌细胞对放化疗的敏感性。为了检验这一假设，在本申请中，我们提出 剖析HH通路中O-GlcNAc酰化激活GLI的分子机制，确定如何 GLI O-GlcNAc化受经典和非经典HH信号传导调节，并破译了GLI O-GlcNAc化的作用。 MB体内生长中的OGT- GLI轴。我们的研究可以解决关于一个新的作用的重要问题， HH通路中的O-GlcNAc化与放化疗。我们多方面的调查是基于 前提，并将以强大的科学严谨性进行，从而有望填补知识的重大空白， 在这个领域有着深远的概念性进展。从翻译的角度，阐述了 MB中O-GlcNAc失调的意义可以提供一种新的生物标志物和潜在的替代物 治疗HH依赖性MB患者的治疗策略。