The Role of the Fructose-1,6-Bisphoshatase 2 and c-Myc Interaction in Sarcoma Progression

果糖-1,6-双磷酸酶 2 和 c-Myc 相互作用在肉瘤进展中的作用

• 批准号: 10536204
• 负责人: Bailey Nance
• 金额: $ 4.68万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 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 2026-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10536204
• 关键词: Adult; Affect; Alanine; Alleles; Attenuated; Binding; Binding Sites; Biogenesis; Biological Assay; CDK4 gene; Cartilage; Cell Cycle; Cell Cycle Regulation; Cell Fractionation; Cell Nucleus; Cells; Co-Immunoprecipitations; Complement; Complex; Connective Tissue; Cytoplasm; Data; Dependence; Disease; Down-Regulation; Enzymes; Excision; Exhibits; Exposure to; Fatty acid glycerol esters; Fructose; Fructose-1,6-Bisphosphatase; Gene Expression; Genetic; Genetic Transcription; Gluconeogenesis; Glucose; Growth; Heterogeneity; Histologic; Hypoxia; In Vitro; Malignant Neoplasms; Maps; Measures; Mediating; Mesenchymal Cell Neoplasm; Metabolic; Metabolism; Methods; Mitochondria; Modeling; Molecular; Molecular Conformation; Mus; Muscle; N-terminal; Nuclear; Nuclear Export; Nuclear Translocation; Operative Surgical Procedures; Oxidative Phosphorylation; Patients; Play; Protein Isoforms; Proteins; Recurrence; Research; Resistance; Role; Scanning; Signal Transduction; Site; Site-Directed Mutagenesis; Soft tissue sarcoma; Stimulus; Structure; Therapeutic; analytical ultracentrifugation; aurora kinase A; c-myc Genes; cdc Genes; chemotherapy; combat; confocal imaging; conventional therapy; dimer; effective therapy; epigenetic silencing; experimental study; functional outcomes; genetic signature; glucose metabolism; glucose uptake; improved; in vivo; inhibitor; insight; mouse model; mutant; novel; novel therapeutics; prediction algorithm; promoter; protein protein interaction; restoration; sarcoma; sedimentation velocity; small molecule inhibitor; transcriptome sequencing; treatment response; tumor; tumor growth

PROJECT SUMMARY Soft tissue sarcomas (STSs) are diverse mesenchymal tumors that occur within connective tissues such as muscle, fat, and cartilage. STS is a highly heterogeneous malignancy with over 70 genetic and histological subtypes. In addition, high rates of recurrence and lack of effective treatment for patients emphasize the need to identify novel therapeutic vulnerabilities common to multiple STS subtypes. Metabolically, STS tumors consistently exhibit high rates of glucose uptake and robust hypoxia gene signatures in patients. Therefore, we focused on fructose-1,6-bisphosphatase (FBP), a rate-limiting enzyme in gluconeogenesis, to combat the typical glycolytic dependence of STS. In previous studies, we showed that FBP2, the muscle-specific isoform of FBP, is severely downregulated in several prevalent STS subtypes. Surprisingly, FBP2 re-expression in STS in vivo opposes sarcoma progression through two spatially distinct mechanisms in the cytoplasm and the nucleus. FBP2 restoration decreases cytosolic glycolytic flux while nuclear FBP2 directly binds to c-Myc, a transcriptional regulator of growth and metabolism. This interaction attenuates c-Myc-dependent expression of TFAM, a key regulator of mitochondrial biogenesis, thereby inhibiting oxidative phosphorylation. These mechanisms, at least in part, contribute to the ability of re-expressed FBP2 to suppress tumor growth in murine STS models. However, my preliminary data suggest that nuclear FBP2 may also directly regulate other c-Myc cell cycle target genes CDK4 and AURKA to contribute to STS suppression. Moreover, how FBP2 regulates c-Myc and the sites of FBP2/c-Myc binding are not known. Recent studies suggest that FBP2 oligomerization and conformation may also play an important role in FBP2's nuclear-to-cytosolic shuttling, and reveal new binding sites for other proteins in the nucleus like c-Myc. Therefore, I hypothesize that the exposed N-terminal regions of tetrameric FBP2 complexes bind directly to c-Myc, contributing to STS suppression by inhibiting both TFAM and cell cycle regulators. In Aim 1, I will map the sites of interaction between FBP2 and c-Myc and determine whether the tetrameric state of FBP2 is necessary for binding. In Aim 2, I will explore the functional outcomes of the FBP2/c-Myc interaction in sarcoma, including the regulation of cell cycle genes AURKA and CDK4. Together, this proposal will provide more insight into the recently discovered nuclear functions of FBP2 to create novel therapies for a diverse set of genetically heterogeneous sarcomas.

项目概要 软组织肉瘤 (STS) 是一种发生在结缔组织内的多种间质肿瘤，例如 肌肉、脂肪和软骨。 STS 是一种高度异质性恶性肿瘤，具有 70 多种遗传和组织学特征 亚型。此外，高复发率和患者缺乏有效治疗强调了需要 识别多种 STS 亚型常见的新治疗漏洞。从代谢角度来看，STS 肿瘤 患者始终表现出高葡萄糖摄取率和强大的缺氧基因特征。因此，我们 专注于果糖-1,6-双磷酸酶（FBP），一种糖异生过程中的限速酶，以对抗典型的 STS 的糖酵解依赖性。在之前的研究中，我们表明 FBP2（FBP 的肌肉特异性亚型） 在几种流行的 STS 亚型中严重下调。令人惊讶的是，FBP2 在体内 STS 中重新表达 通过细胞质和细胞核中两种空间上不同的机制来阻止肉瘤的进展。 FBP2 恢复减少胞质糖酵解通量，而核 FBP2 直接与 c-Myc（一种转录因子）结合 生长和新陈代谢的调节剂。这种相互作用减弱了 TFAM 的 c-Myc 依赖性表达，这是一个关键 线粒体生物合成的调节因子，从而抑制氧化磷酸化。这些机制至少 在一定程度上，有助于重新表达 FBP2 抑制小鼠 STS 模型中肿瘤生长的能力。然而， 我的初步数据表明核FBP2也可能直接调节其他c-Myc细胞周期靶基因 CDK4 和 AURKA 有助于 STS 抑制。此外，FBP2 如何调节 c-Myc 及其位点 FBP2/c-Myc 结合尚不清楚。最近的研究表明 FBP2 寡聚化和构象可能 在 FBP2 的核到胞质穿梭中也发挥着重要作用，并揭示了其他蛋白质的新结合位点 像c-Myc一样存在于细胞核中。因此，我假设四聚体 FBP2 暴露的 N 端区域 复合物直接与 c-Myc 结合，通过抑制 TFAM 和细胞来抑制 STS 循环调节器。在目标 1 中，我将绘制 FBP2 和 c-Myc 之间相互作用的位点，并确定是否 FBP2 的四聚体状态是结合所必需的。在目标 2 中，我将探讨 肉瘤中 FBP2/c-Myc 相互作用，包括细胞周期基因 AURKA 和 CDK4 的调节。一起， 该提案将为最近发现的 FBP2 核功能提供更多见解，以创造新的 针对多种遗传异质性肉瘤的疗法。