Posttranslational regulation of augurin, a new secretory tumor suppressor

新型分泌型肿瘤抑制因子 Augurin 的翻译后调控

• 批准号: 8510965
• 负责人: Akihiko Ozawa
• 金额: $ 25.95万
• 依托单位: TORREY PINES INST FOR MOLECULAR STUDIES
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8510965
• 关键词: Acylation; Address; Adult; Aging; Biological; Biological Assay; Biological Markers; Biology; Biopsy; Brain; Brain Neoplasms; Cancer cell line; Cell Aging; Cell Death; Cell Differentiation process; Cell Line; Cell Proliferation; Cell Proliferation Regulation; Cells; Cleaved cell; Corticotropin; Data; Development; Drops; Enhancers; Esophagus; Exhibits; Family; Future; Genes; Genome; Glioblastoma; Glioma; Goals; Grant; Growth; Hypermethylation; Hypothalamic structure; In Vitro; Inorganic Sulfates; Link; Malignant Neoplasms; Malignant neoplasm of brain; Malignant neoplasm of esophagus; Mass Spectrum Analysis; Messenger RNA; Metabolism; Molecular; Monitor; Mus; Neurons; Pathway interactions; Patients; Peptides; Physiological; Physiological Processes; Pituitary Gland; Plasma; Play; Positioning Attribute; Post-Translational Protein Processing; Post-Translational Regulation; Proprotein Convertases; Proteolytic Processing; RNA; Radioimmunoassay; Receptor Signaling; Regulation; Reporting; Role; Signal Pathway; Site; Staging; Staining method; Stains; Surgical Management; Testing; Therapeutic; Thyroid Gland; Time; Tumor Cell Line; Tumor Suppression; Tumor Suppressor Genes; Tumor Suppressor Proteins; Tumor-Derived; Tyrosine; Unspecified or Sulfate Ion Sulfates; Vertebrates; cancer type; cartilage development; cell type; liquid chromatography mass spectrometry; member; neoplastic cell; promoter; public health relevance; research study; restoration; secretory protein; sulfation; synthetic peptide; trafficking; tumor

DESCRIPTION (provided by applicant): Glioblastoma is the most common type of primary malignant brain tumor in adults and one of the most aggressive cancers. Even though there have been recent advances in surgical management of this type of cancer, the median survival time for these patients is approximately 14 months, most likely due to the loss of tumor suppressor expression within the tumor genome. Monitoring the level of certain molecules in either plasma or brain biopsies might provide us with information regarding the development/progression of a possible glioblastoma in early stage. Augurin, recently identified as a potential tumor suppressor, is a secretory molecule produced in the pituitary, brain, thyroid, and esophagus. It is implicated in a wide array of physiological processes, from ACTH release to tumor suppression, and is well conserved among all vertebrates. Most interestingly, the expression of augurin is down-regulated by promoter hypermethylation in certain types of cancers, including glioblastoma. Secretory proteins are involved in diverse physiological functions, such as the regulation of metabolism, cell proliferation, differentiation, and cell deat; they require a number of posttranslational modifications during their trafficking through the secretory pathway in order to attain bioactive status. Without these posttranslational modifications, secretory proteins cannot exert their biological activities, resulting in deficiencis in physiological functions. However, information regarding the endogenous forms of proaugurin-derived peptides in various cell types has yet to be reported. The goal of this proposal is to understand the posttranslational modifications of proaugurin as a tumor suppressor. Our recent report has shown that two specific proaugurin-derived peptides are generated by the action of the specific proprotein convertase furin in vitro. Furthermore, we have found that proaugurin is sulfated during trafficking through the secretory pathway. Proliferation assays with a glioblastoma cell line demonstrated that only furin-cleaved proaugurin could suppress cell proliferation, suggesting that proteolytic cleavage is a posttranslational requirement for proaugurin to exhibit bioactivity. In addition, the predicted sulfation sites in augurin are highly conserved among other species, supporting the idea that sulfation in augurin might contribute to the suppressive activity against tumor cell proliferation. In this proposal, we will determine the bioactive species of augurin that function to suppress tumor cell proliferation using its synthetic peptides of proaugurin-derived peptides; perform mass spectrometry to determine the sulfation site(s) in augurin and clarify the importance of sulfation in augurin; determine the augurin levels in normal and glial tumor-bearing mice using radioimmunoassay and immunohistochemical staining, to test the idea that lowered augurin expression may be a potential indicator of tumor-developing cells. These experiments will help to reveal molecular mechanisms involved in proaugurin maturation, and will provide clues to its biological importance as a tumor suppressor.

描述（由申请人提供）：胶质母细胞瘤是成年人和最具侵略性癌症中最常见的原发性恶性脑肿瘤类型。即使最近的这种类型癌症的手术管理方面取得了进步，但这些患者的中位生存时间约为14个月，这很可能是由于肿瘤基因组中肿瘤抑制剂表达的丧失。监测血浆或脑活检中某些分子的水平，可能会为我们提供有关早期胶质母细胞瘤发展/进展的信息。 Augurin最近被确定为潜在的肿瘤抑制剂，是垂体，脑，甲状腺， 和食道。它与从ACTH释放到肿瘤抑制的各种生理过程有关，在所有脊椎动物中都保守了。最有趣的是，在包括胶质母细胞瘤在内的某些类型的癌症中，在某些类型的癌症中启动子高甲基化的表达被启动子高甲基化下调。分泌蛋白参与了多种生理功能，例如代谢，细胞增殖，分化和细胞deat的调节；他们需要在分泌途径的贩运过程中进行一些翻译后的修改，以达到生物活性状态。没有这些翻译后修饰，分泌蛋白就无法发挥其生物学活性，从而导致生理功能缺乏。然而，有关各种细胞类型中促孕肽衍生肽的内源性形式的信息尚未报道。该提案的目的是了解proaugurin作为肿瘤抑制剂的翻译后修饰。我们最近的报告表明，在体外特定的前蛋白转化蛋白脂肪蛋白的作用产生了两个特定的促尿素衍生的肽。此外，我们发现proaugurin在通过分泌途径的贩运过程中被硫化。用胶质母细胞瘤细胞系的增殖测定表明，只有脂肪蛋白裂解的促素蛋白才能抑制细胞的增殖，这表明蛋白水解裂解是促促促素蛋白表现出生物活性的翻译后需求。另外，杜布林中预测的硫酸盐位点高度 在其他物种中保守的，支持这样一种观念，即含元素中的硫酸盐可能有助于抑制肿瘤细胞增殖的活性。在此提案中，我们将确定使用其合成的元素的生物活性物种，以抑制肿瘤细胞的增殖 促昆蛋白衍生的肽的肽；执行质谱法以确定Augurin中的硫酸盐位点，并阐明硫素中硫酸盐的重要性；确定奥古蛋白水平 在正常和神经胶质肿瘤的小鼠中，使用放射免疫测定法和免疫组织化学染色，以测试降低的含元素表达的想法可能是肿瘤发育细胞的潜在指标。这些实验将有助于揭示参与促王素成熟的分子机制，并为其作为肿瘤抑制剂的生物学重要性提供线索。