Crosstalk of LKB1 and KEAP1 mutations in driving growth of lung adenocarcinoma

LKB1 和 KEAP1 突变的串扰驱动肺腺癌的生长

• 批准号: 9107950
• 负责人: Shyam Biswal
• 金额: $ 40.34万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-15 至 2021-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9107950
• 关键词: 5' -AMP-activated protein kinase; Adenocarcinoma; Adenocarcinoma Cell; Affect; Animals; Antioxidants; Automobile Driving; Cell Line; Cell Proliferation; Cell Survival; Cells; Collaborations; Data; Defect; Drug Metabolic Detoxication; Gene Mutation; Gene Silencing; Genetic; Genetically Engineered Mouse; Growth; Histologic; Homeostasis; Human; In Vitro; Knock-out; Knowledge; Lead; Lung; Lung Adenocarcinoma; Lung Neoplasms; Malignant Neoplasms; Malignant neoplasm of lung; Metabolic; Metabolic Pathway; Metabolic stress; Modeling; Molecular; Mus; Mutate; Mutation; NADP; Non-Small-Cell Lung Carcinoma; Nutrient; Oncogenic; Oxidation-Reduction; Pathway interactions; Proteins; Reaction; Reactive Oxygen Species; Resistance; Role; STK11 gene; Signal Transduction; Stress; The Cancer Genome Atlas; Transgenic Mice; Up-Regulation; cell growth; energy balance; expectation; improved; in vivo; inhibitor/antagonist; loss of function mutation; lung tumorigenesis; metabolomics; mortality; mouse model; mutant; neoplastic cell; new therapeutic target; novel; pre-clinical; public health relevance; response; small molecule; stable isotope; transcriptomics; tumor; tumor growth

 DESCRIPTION (provided by applicant): Nearly 25% of lung adenocarcinomas (LuAD) have deletions or inactivating mutations of the gene for LKB1. In response to metabolic stress, wildtype LKB1 promotes catabolic reactions for generating ATP and conserving antioxidant (NADPH and GSH) levels. Since LKB1 counteracts ROS resulting from metabolic stress, the inactivation of this gene in cancer seems to be contrary to expectations, and indeed, LKB1-deficient cells are relatively resistant to oncogenic transformation and sensitive to metabolic stress. TCGA sequencing data revealed that ~ 50% of LKB1-mutant LuAD also harbor a Kelch-ECH associated protein 1 (KEAP1) mutation. Can the impaired ability of LKB1-deficient cells to adapt to nutrient and metabolic stress be overcome by parallel loss of KEAP1? Our preliminary studies revealed that combined loss of Lkb1 and Keap1 decrease ROS and dramatically enhances tumor growth (histologically, adenocarcinomas), and mortality in KrasG12D driven mouse model of lung cancer. Even in the absence of oncogenic Kras signaling, Keap1-/-Lkb1-/- animals form tumors in the lungs with long latency. Importantly, LKB1-deficient cells showed impaired ability to adapt to metabolic stress in the absence of Nrf2 pathway activation, but this defect was rescued by simultaneous loss of Keap1 signaling. KEAP1 mutations lead to gain of NRF2 function in NSCLC that drives antioxidant pathways and metabolic alterations. We hypothesize that KEAP1 mutations in LKB1 mutated lung adenocarcinoma cells causes gain of NRF2 for ROS detoxification and metabolic pathway alterations, which are critical for tumor cell survival. To exploit the vulnerability of this adaptation, we hypothesize that inhibiting NRF2 in tumors with loss of LKB1 and KEAP1 will decrease tumor growth due to metabolic stress. Specific aim 1 will determine if selective loss of Keap1 signaling in Lkb1 deficient lung cells maintains cellular redox homeostasis and promotes lung tumorigenesis. We have developed mouse models with selective deletion of Lkb1 and Keap1 (with or without oncogenic stress - KrasG12D), transgenic mice expressing Nrf2 with activating mutation combined with Lkb1 deletion as well as LKB1 mutant human lung adenocarcinoma cell lines with gain of Nrf2 or loss of Keap1 function. Specific aim 2 will determine the mechanisms by which loss of Keap1 signaling cooperates with Lkb1 signaling for metabolic alterations to provide survival advantage. Transcriptomic and stable isotope resolved metabolomics studies will be performed. Specific aim 3 will determine if disruption of Nrf2 signaling in our mouse models of SA 1 will decrease tumor growth and improve survival using genetic as well as small molecule approach. In addition to genetic knockout of Nrf2, our preliminary studies have shown the efficacy of a novel small molecule (developed in collaboration with NCATS) for inhibiting NRF2 in vitro and in which will be explored for its potential for targeting the Nrf2 pathway in treating LKB1-mutant cancers. These studies will (a) provide the molecular understanding of why 50% of LKB1 loss coexist with KEAP1 mutations in LuAD (b) create the preclinical knowledge essential for targeting this cooperation.

 描述（由适用提供）：将近25％的肺腺癌（LUAD）具有LKB1基因的缺失或灭活突变。响应代谢应激，WildType LKB1促进了生成ATP和保护抗氧化剂（NADPH和GSH）水平的分解代谢反应。由于LKB1抵消了由代谢应激引起的ROS，因此该基因在癌症中的失活似乎与期望形成对比，实际上，LKB1缺陷细胞对致癌转化具有相对抗性，并且对代谢应激敏感。 TCGA测序数据表明，约有50％的LKB1突变剂LUAD还具有Kelch-Ech相关蛋白1（KEAP1）突变。 LKB1缺陷细胞适应营养和代谢应激的能力是否可以通过平行的KEAP1损失来克服？我们的初步研究表明，LKB1和KEAP1的总损失降低了ROS，并大大增强了肿瘤的生长（组织学上，腺癌）和KRASG12D驱动小鼠肺癌模型的死亡率。即使在没有致癌的KRAS信号传导的情况下，Keap1 - / - LKB1 - / - 动物在肺部的肿瘤中延迟较长。重要的是，在没有NRF2途径激活的情况下，LKB1缺陷型细胞显示出适应代谢应激的能力受损，但是由于简单的KEAP1信号传导丢失而挽救了该缺陷。 KEAP1突变导致NSCLC中NRF2功能的增强，从而驱动抗氧化途径和代谢改变。我们假设LKB1中的KEAP1突变突变导致肺腺癌细胞导致NRF2的ROS ROS排毒和代谢途径改变，这对于肿瘤细胞的存活至关重要。为了利用这种适应的脆弱性，我们假设抑制LKB1和KEAP1损失的肿瘤中的NRF2将因代谢应激而降低肿瘤的生长。具体目标1将确定LKB1缺失中KEAP1信号传导的选择性丢失以及LKB1突变体人肺腺癌细胞系具有NRF2的增益或KEAP1功能的丧失。具体目标2将确定Keap1信号传导损失与LKB1信号传导合作以提供代谢改变以提供生存优势的机制。将进行转录组和稳定的同位素分辨代谢组学研究。特定的目标3将确定我们的SA 1小鼠模型中NRF2信号传导的破坏是否会减少肿瘤的生长并使用遗传和小分子方法提高生存率。除NRF2的遗传敲除外，我们的初步研究还表明，一种新型的小分子（与NCATS合作开发）在体外抑制NRF2的效率，并将其探索其靶向NRF2途径在处理LKB1突变体中的潜力。这些研究将（a）提供分子理解为什么LUAD中50％的LKB1损失与KEAP1突变共存（b）创造了针对这种合作至关重要的临床前知识。