Role of de Novo Synthesis of Sphingolipids in Aneuploid Cells

鞘脂从头合成在非整倍体细胞中的作用

• 批准号: 10084296
• 负责人: Eduardo Martin Torres
• 金额: $ 33.08万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-02-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10084296
• 关键词: Affect; Anabolism; Aneuploid Cells; Aneuploidy; Cell Cycle; Cell Cycle Arrest; Cell physiology; Cells; Ceramides; Chromosomes; Clinic; Clinical; DNA Sequence Alteration; Data; Dependence; Development; Disease; Down Syndrome; Drug Targeting; Drug Utilization; Enzymes; Equilibrium; Eukaryota; Gene Deletion; Gene Expression; Genes; Growth; Human; Intellectual functioning disability; Lead; Lipids; Literature; Malignant Neoplasms; Metabolic; Metabolic Pathway; Metabolism; Molecular; Mutation; Neurodegenerative Disorders; Normal Cell; Pathway interactions; Phenotype; Phosphoric Monoester Hydrolases; Phosphotransferases; Physiological; Play; Process; Prognosis; Proliferating; Proteins; Proteome; Regulation; Role; Series; Serine; Signal Pathway; Signaling Molecule; Sphingolipids; Sphingosine; Stress; Tumor Biology; Yeasts; anti-cancer; cancer cell; cancer type; chromosome number abnormality; fitness; genetic approach; human disease; improved; insight; lipid metabolism; novel; pressure; proteotoxicity; response; serine palmitoyltransferase; tumor

Abstract Aneuploidy, a cellular state of having an abnormal number of chromosomes, is a hallmark of cancer. The degree of aneuploidy significantly correlates with tumor aggressiveness and poor clinical prognosis. Therefore, studying the cellular processes affected by aneuploidy can improve our understanding of the role of aneuploidy in tumor biology. Our preliminary results show that de novo synthesis of sphingolipids is increased by aneuploidy; we therefore propose to identify the molecular mechanisms underlying this effect. Targeting the synthesis of sphingolipids holds great potential as an anti-cancer strategy that could be used either alone or in combination with existing therapies. Despite the existence of a large body of literature providing strong evidence for the misregulation of sphingolipid metabolism in human diseases, including several types of cancers, the molecular mechanisms that lead to this misregulation are poorly understood. The focus of this proposal is to unravel the molecular mechanisms that regulate de novo synthesis of sphingolipids and to decipher how these mechanisms are affected in aneuploid cells. To this end, we propose to: (1) Determine how aneuploidy increases sphingolipid biosynthesis. Our preliminary data supports the hypothesis that aneuploid cells rely on the increased activity of serine palmitoyltransferase, the enzyme that controls the first and irreversible step of sphingolipid synthesis, to proliferate. Therefore, we will investigate the function of signaling pathways that regulate serine palmitoyltransferase in aneuploidy. In addition, because serine serves as a precursor for sphingolipids, we will investigate whether aneuploidy leads to increased serine utilization. To that end, we plan to quantify serine metabolic flux through the sphingolipid pathway in aneuploid cells. Our studies will provide novel insights into how sphingolipid synthesis is affected in response to aneuploidy. (2) Determine how sphingolipid levels control the fitness of aneuploid cells. Our preliminary results show that mutations in four different genes that increase the levels of sphingosine and lower those of ceramide, improve the fitness of aneuploid cells. Therefore, we will determine, in aneuploid cells, the function of Pkh1/2 kinases and Cdc55 phosphatase because these signaling molecules are known to act downstream of sphingolipids and regulate the cell cycle and responses to stress. In addition, we will determine specific cellular pathways and processes that play an important role in overcoming the detrimental effects of aneuploidy. Gene expression, proteome content, and phenotypic analyses in combination with genetic approaches will be used to accomplish this aim. Altogether, our studies will contribute to a better understanding of the physiological role of sphingolipids in controlling the fitness of aneuploid cells. Determining the mechanisms that control the fitness of aneuploid cells can be exploited to target aneuploid cancer cells and to ameliorate the deleterious effects of aneuploidy in Down syndrome or neurodegenerative diseases.

摘要 非整倍体是一种染色体数目异常的细胞状态，是癌症的一个标志。这个 非整倍体程度与肿瘤侵袭性和临床预后密切相关。因此， 研究非整倍体对细胞过程的影响有助于我们更好地理解非整倍体的作用 在肿瘤生物学方面。我们的初步结果表明，鞘糖脂的从头合成增加了 非整倍体；因此，我们建议确定这种效应背后的分子机制。目标是 鞘磷脂的合成作为一种抗癌策略具有巨大的潜力，既可以单独使用，也可以用于 与现有疗法相结合。尽管大量文献的存在提供了强大的 人类疾病中鞘磷脂代谢失调的证据，包括几种类型的 癌症，导致这种错误调控的分子机制还知之甚少。这件事的重点是 建议揭开调节鞘磷脂从头合成的分子机制，并 破译这些机制是如何影响非整倍体细胞的。为此，我们建议：(1)确定 非整倍体如何增加鞘脂的生物合成。我们的初步数据支持这样一种假设 非整倍体细胞依赖于丝氨酸棕榈酰转移酶活性的增加，这种酶控制着第一个 神经鞘脂合成的不可逆转的步骤，以增殖。因此，我们将研究它的功能 非整倍体中调节丝氨酸棕榈酰转移酶的信号通路。此外，因为丝氨酸提供 作为鞘脂的前体，我们将调查非整倍体是否会导致丝氨酸利用率的增加。至 最后，我们计划通过非整倍体细胞中的鞘磷脂途径来量化丝氨酸代谢流量。我们的 研究将提供新的见解，了解鞘脂合成是如何受到非整倍体的影响的。(2) 确定鞘脂水平如何控制非整倍体细胞的适合性。我们的初步结果显示， 四个不同基因的突变提高了鞘氨醇水平，降低了神经酰胺水平，改善了 非整倍体细胞的适合性。因此，我们将在非整倍体细胞中确定Pkh1/2激酶的功能 和CDC55磷酸酶，因为这些信号分子已知作用于鞘脂下游和 调节细胞周期和对压力的反应。此外，我们将确定特定的细胞通路和 在克服非整倍体的有害影响方面发挥重要作用的过程。基因表达， 蛋白质组含量和表型分析将与遗传方法相结合来完成 这个目标。总之，我们的研究将有助于更好地理解 鞘磷脂在控制非整倍体细胞适合性中的作用。确定控制健康的机制 可以利用非整倍体细胞来靶向非整倍体癌细胞并改善 唐氏综合征或神经退行性疾病中的非整倍体。

项目成果

Consequences of aneuploidy in human fibroblasts with trisomy 21.

• DOI: 10.1073/pnas.2014723118
• 发表时间: 2021-02-09
• 期刊: Proceedings of the National Academy of Sciences of the United States of America
• 影响因子: 11.1
• 作者: Hwang S;Cavaliere P;Li R;Zhu LJ;Dephoure N;Torres EM
• 通讯作者: Torres EM