DIRAS3 disrupts K-RAS clustering and signaling, enhancing autophagy and response to autophagy inhibition

DIRAS3 破坏 K-RAS 聚类和信号传导，增强自噬和对自噬抑制的反应

基本信息

批准号：
10707965
负责人：
ROBERT C BAST
金额：
$ 66.7万
依托单位：
UNIVERSITY OF TX MD ANDERSON CAN CTR
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-09-21 至 2027-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10707965
关键词：
Accounting Affinity Amino Acids Apoptosis Apoptotic Autophagocytosis BRAF gene Binding Biological Biological Process C-terminal Cancer Cell Growth Cancer cell line Cell Proliferation Cell Respiration Cell membrane Cells Consumption Cytoplasm Development Dimerization Disease Eating Epithelium Exhibits FRAP1 gene Family member Fatty Acids GTP Binding Genetically Engineered Mouse Goals Grant Growth Guanosine Triphosphate Phosphohydrolases Heterodimerization Homodimerization Human Incidence Inhibition of Cancer Cell Growth Inhibition of Cell Proliferation KRAS oncogenesis KRAS2 gene KRASG12D Laboratories Malignant Neoplasms Malignant neoplasm of ovary Malignant neoplasm of pancreas Mediating Membrane Metabolic Mutation N-terminal Neoplasm Metastasis Nuclear Nutrient Oncogenic Organelles Ovarian Carcinoma Ovarian Serous Adenocarcinoma Pancreatic Ductal Adenocarcinoma Peptides Physiological Prevalence Prognosis Proteins RAS driven cancer RAS inhibition Ras Inhibitor Recurrent disease Role STK11 gene Serous Signal Induction Signal Pathway Signal Transduction Site Surface Testing Therapeutic Tumor Suppressor Proteins Xenograft procedure cancer cell cell growth cell motility cell transformation cellular engineering dimer inhibition of autophagy inhibitor migration monomer mutant myristoylation nanocluster new therapeutic target novel novel strategies novel therapeutic intervention novel therapeutics pancreatic ductal adenocarcinoma cell pancreatic ductal adenocarcinoma model prenylation rare cancer response stapled peptide targeted treatment treatment strategy tumor

项目摘要

Mutant KRAS drives human cancers from several sites, including pancreatic ductal adenocarcinoma (PDAC) and low-grade serous ovarian cancer (LGSOC). Despite the prevalence of RAS mutations in different cancers, effective RAS-targeted treatment remains a challenge. KRAS monomers form homodimers and nanoclusters in the cell membrane to optimize signaling and to transform cells efficiently. Dimerization of KRAS is required for RAS-driven transformation and cancer growth. Agents that disrupt mutant RAS dimers and clusters can block oncogenic activity. Recent evidence indicates that inhibition of RAS signaling induces autophagy and enhances the response to anti-autophagic therapy. Despite four decades of effort, development of effective strategies for the treatment for mutant KRAS-driven cancers remains a work in progress. Our laboratory has discovered a novel endogenous physiological RAS inhibitor designated DIRAS3, a 26 KDa GTPase sharing 50-60% homology with classical RAS family members, but with a distinctive 34 amino acid N-terminal extension that reverses RAS function. Like RAS, DIRAS3 is prenylated at the C-terminal CAAX site, binds GTP with high affinity, exhibits weak GTPase activity, and requires membrane association for its biological function. DIRAS3 is downregulated in a number of cancers including PDAC and LGSOC, and re-expression of DIRAS3 blocks cancer cell proliferation, inhibits motility, and, importantly, induces autophagy by multiple mechanisms. Recently we have found that DIRAS3 and a DIRAS3-derived stapled peptide from its α5 domain interact directly with mutant KRAS, reducing KRAS dimerization and nanoclustering, and inhibiting KRAS signaling. Both intact DIRAS3 and DIRAS3-derived stapled peptide induce autophagy and potentiate the pro-apoptotic activity of autophagy inhibitors in PDAC and LGSOC cells. In this proposal, we will study the effect of DIRAS3 on KRAS-dependent cell growth, migration and effector signaling in MEF cells and genetically engineered mouse model with mutant KRAS, as well as in KRAS-driven PDAC and LGSOC, better defining the mechanism by which DIRAS3 inhibits KRAS (Aim 1). We will investigate the mechanisms by which DIRAS3 induces autophagy in KRAS-driven PDAC and LGSOC (Aim 2). Finally, we will test the ability of DIRAS3 or a DIRAS3-derived stapled peptide in combination with autophagy inhibitors (CQ/DC661) to enhance apoptosis and growth inhibition in PDAC and LGSOC (Aim3). These studies will not only lay the groundwork for exploring new therapeutic strategies targeting KRAS-mutant cancers, but also contribute to a fundamental understanding of the mechanisms by which DIRAS3, as a tumor suppressor, inhibits mutant KRAS activity and induces autophagy.

突变的KRAS从几个地点驱动人类癌症，包括胰腺导管腺癌（PDAC）和低级浆液卵巢癌（LGSOC）。尽管不同癌症中RAS突变的流行率，但有效的RAS靶向治疗仍然是一个挑战。 KRAS单体形成同型二聚体和纳米簇细胞膜以优化信号并有效地转化细胞。需要Kras的二聚化 RAS驱动的转化和癌症的增长。破坏突变体Ras二聚体和簇的代理可以阻止致癌活性。最近的证据表明，抑制RAS信号传导会诱导自噬并增强对抗自助疗法的反应。尽管努力了四十年，但开发了有效的策略对突变KRAS驱动的癌症的治疗仍然是一项正在进行的工作。我们的实验室发现了一个新型的内源性物理RAS抑制剂指定DIRAS3，共享50-60％同源性的26 kDa GTPase 具有经典的RAS家族成员，但具有独特的34个氨基酸N末端扩展，可逆转RAS 功能。像RAS一样，DIRAS3在C末端CAAX位点进行了核心，具有高亲和力的GTP，展示 GTPase活性弱，并且需要膜关联才能获得其生物学功能。 diras3被下调在包括PDAC和LGSOC在内的许多癌症中增殖，抑制运动性，重要的是，通过多种机制诱导自噬。最近我们有发现DIRAS3和来自其α5域的Diras3衍生的固定肽直接与突变的KRAS相互作用，减少KRAS二聚化和纳米簇，并抑制KRAS信号传导。既完整diras3 and DIRAS3衍生的固定肽诱导自噬和潜在的自噬的促凋亡活性 PDAC和LGSOC细胞中的抑制剂。在此提案中，我们将研究diras3对KRAS依赖性的影响 MEF细胞中的细胞生长，迁移和效应子信号传导以及具有突变体的基因工程小鼠模型 KRAS以及KRAS驱动的PDAC和LGSOC中，更好地定义了DIRAS3抑制的机制克拉斯（目标1）。我们将研究DIRAS3在KRAS驱动的PDAC中诱导自噬的机制和LGSOC（AIM 2）。最后，我们将测试diras3或diras3衍生的固定肽的能力结合自噬抑制剂（CQ/DC661），以增强PDAC和PDAC的凋亡和生长抑制作用 LGSOC（AIM3）。这些研究不仅将为探索针对目标的新治疗策略奠定基础 Kras突变癌，但也有助于对Diras3的机制有基本的理解作为肿瘤抑制器，抑制突变体Kras活性并诱导自噬。