Probing Autophagy Regulation in Cancer with Chemical Approaches

用化学方法探索癌症中的自噬调节

• 批准号: 7614645
• 负责人: Adam Livingston Garske
• 金额: $ 4.52万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-01 至 2012-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7614645
• 关键词: 1-Phosphatidylinositol 3-Kinase; 5' -AMP-activated protein kinase; Address; Alleles; Amino Acids; Apoptosis; Apoptotic; Autophagocytosis; Catabolism; Cell Cycle Arrest; Cell Death; Cell Survival; Cell physiology; Cells; Cellular Stress; Cellular Structures; Chemicals; Development; Diabetes Mellitus; Disease; Drug Delivery Systems; Enzymes; Family; Goals; Growth Factor; Lead; Link; Malignant Neoplasms; Mediator of activation protein; Metabolic stress; Mutagenesis; Mutate; Nature; Nutrient; Organic Synthesis; Outcome; Pathway interactions; Phosphatidylinositols; Phosphotransferases; Process; Protein Isoforms; Protein Kinase Inhibitors; Protein-Serine-Threonine Kinases; Proteins; Reagent; Regulation; Reporting; Research; Role; Signal Pathway; Site-Directed Mutagenesis; Specificity; Starvation; System; Testing; Therapeutic; Variant; Withdrawal; base; cancer cell; cancer therapy; chemical genetics; chemotherapy; genetic inhibitor; glucose uptake; inhibitor/antagonist; insight; kinase inhibitor; mimetics; prevent; programs; protein kinase inhibitor; protein kinase modulator; public health relevance; response; sensor; small molecule; therapeutic target; tool

DESCRIPTION (provided by applicant): The objective of this proposal is to explore the effects of autophagy modulation in the context of cancer. Autophagy is a process in which the cell consumes its own components in response to metabolic stress. The phosphoinositide 3-kinases (PI3-Ks) are among the most frequently mutated proteins in cancer. Inhibition of the class I PI3-Ks has been suggested to induce autophagy. Furthermore, inhibition of PI3-Ks leads to a decrease in the uptake of glucose and amino acids. One hypothesis is that deficiency in nutrients can lead to an increase in the AMP/ATP ratio, subsequent activation of AMP-activated protein kinase (AMPK) and induction of autophagy. This may be a mechanism that prevents cancer cells that are treated with PI3-K inhibitors from undergoing apoptosis. In Aim 1 of the proposal, a panel of small molecule PI3-K inhibitors will be used to dissect the autophagy response upon inhibition of the various PI3-K isoforms in cancer cells. The effects of autophagy modulation by small-molecule AMPK regulators will be explored in the context of PI3-K inhibition. In Aim 2, new chemical genetic tools will be developed for the study of autophagy. AMPK, a master sensor of cellular energy, is emerging as a key enzyme in autophagy regulation. However, chemical modulators of AMPK have been lacking. For example, the only known AMPK inhibitor, compound C, is known to inhibit other kinases. In this aim, using site-directed mutagenesis and organic synthesis, an inhibitor-sensitive allele of AMPK will be developed such that selective inhibition of AMPK can be achieved among the kinase superfamily. Besides non-specific inhibition, until recently, AMPK activation has been achieved by indirectly altering the AMP:ATP ratio or by weak allosteric activation with a nonspecific AMP mimetic, AICAR. A family of thienopyridone AMPK activators has recently been developed, but use of these compounds has not been extensively validated. Therefore, a specific and potent chemical genetic AMPK-activator will be developed using random mutagenesis to sensitize AMPK to activation by a thienopyridone derivative that does not activate wild-type AMPK. Finally, in Aim 3, uncoordinated 51-like kinase 1 (ULK1), a critical regulator of autophagasome formation, will be examined as a potential drug target with chemical genetics. There are no known inhibitors for this kinase and, therefore, development of a chemical genetic inhibitor system will lend new insight into how ULK1 regulates autophagy and its potential as a drug target. PUBLIC HEALTH RELEVANCE: The proposed research will explore the links between autophagy, a protective cellular process, and cancer. In addition, new chemical tools will be developed for study of the roles and uses for autophagy.

描述（由申请人提供）：该提案的目的是探索自噬调节在癌症背景下的影响。 自噬是细胞响应代谢应激而消耗自身成分的过程。 磷酸肌醇 3-激酶 (PI3-K) 是癌症中最常见的突变蛋白之一。 有人建议抑制 I 类 PI3-K 可诱导自噬。 此外，PI3-Ks 的抑制会导致葡萄糖和氨基酸的摄取减少。 一种假设是，营养素缺乏会导致 AMP/ATP 比率增加，随后激活 AMP 激活蛋白激酶 (AMPK) 并诱导自噬。 这可能是一种防止接受 PI3-K 抑制剂治疗的癌细胞发生凋亡的机制。 在该提案的目标 1 中，将使用一组小分子 PI3-K 抑制剂来剖析抑制癌细胞中各种 PI3-K 同工型后的自噬反应。 小分子 AMPK 调节剂对自噬调节的影响将在 PI3-K 抑制的背景下进行探讨。 在目标 2 中，将开发新的化学遗传工具用于自噬的研究。 AMPK 是细胞能量的主要传感器，正在成为自噬调节中的关键酶。 然而，AMPK 的化学调节剂一直缺乏。 例如，唯一已知的 AMPK 抑制剂化合物 C 可以抑制其他激酶。 为此，我们将通过定点诱变和有机合成，开发出 AMPK 抑制剂敏感等位基因，从而在激酶超家族中实现对 AMPK 的选择性抑制。 除了非特异性抑制之外，直到最近，AMPK 激活还可以通过间接改变 AMP:ATP 比率或通过非特异性 AMP 模拟物 AICAR 的弱变构激活来实现。 最近开发了一系列噻吩并吡啶酮 AMPK 激活剂，但这些化合物的使用尚未得到广泛验证。 因此，将使用随机诱变开发一种特异且有效的化学遗传 AMPK 激活剂，以使 AMPK 对噻吩并吡啶酮衍生物的激活敏感，而噻吩并吡啶酮衍生物不会激活野生型 AMPK。 最后，在目标 3 中，不协调的 51 样激酶 1 (ULK1)（自噬体形成的关键调节因子）将作为化学遗传学的潜在药物靶点进行检查。 这种激酶尚无已知的抑制剂，因此，化学遗传抑制剂系统的开发将为 ULK1 如何调节自噬及其作为药物靶点的潜力提供新的见解。 公共健康相关性：拟议的研究将探讨自噬（一种保护性细胞过程）与癌症之间的联系。 此外，还将开发新的化学工具来研究自噬的作用和用途。