Elucidate the mechanism of autophagy in supporting Lkb1-deficient lung tumorigenesis and metastasis

阐明自噬支持 Lkb1 缺陷型肺肿瘤发生和转移的机制

基本信息

批准号：
10063978
负责人：
Yanxiang Guo
金额：
$ 36.16万
依托单位：
RBHS -CANCER INSTITUTE OF NEW JERSEY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-02-01 至 2025-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10063978
关键词：
5&apos -AMP-activated protein kinase Ablation Accounting Address Adenocarcinoma Adenocarcinoma Cell Autophagocytosis Biological Models Bypass Cancer Etiology Cancer Patient Catabolic Process Cell Proliferation Cell Survival Cells Clinical Trials Essential Genes Frequencies Genes Genetic Predisposition to Disease Genetically Engineered Mouse Goals Homeostasis Impairment In Vitro K-ras mouse model KRAS2 gene KRASG12D Lung Neoplasms Malignant Neoplasms Malignant neoplasm of lung Mediating Metabolic Metabolic stress Metabolism Metastatic Neoplasm to the Lung Mus Mutate Mutation Neoplasm Metastasis Non-Small-Cell Lung Carcinoma Normal tissue morphology Nutrient Oncogenic Organelles Patients Play Process Prognosis Property Proteins Resistance Role STK11 gene Squamous cell carcinoma Starvation TP53 gene Testing Therapeutic Transition Career Development Award (K22)base cancer cell cancer therapy exome sequencing extracellular fatty acid metabolism genome-wide improved in vivo inhibition of autophagy insight knock-down lipid metabolism loss of function lung cancer cell lung tumorigenesis mortality mouse model mutant neoplastic cell novel pre-clinical predictive marker response targeted treatment transdifferentiation tumor tumor growth tumor initiation tumor metabolism tumorigenesis

项目摘要

Abstract Lung cancer is the leading cause of cancer mortality, with non-small cell lung cancer (NSCLC) accounting for more than 85% of these cases. KRAS, the most common oncogenic driver in NSCLC, confers a poor prognosis with limited treatment options. LKB1 is the third most frequently mutated gene in NSCLC. The mutations in both KRAS and LKB1 account for about 30% of NSCLC, with increased aggressiveness, a high frequency of metastases and resistance to therapeutics. Autophagy degrades proteins and organelles and recycles them to provide metabolic substrates, a function that is critical when extracellular nutrients are limited. Although the role of autophagy in cancer has been intensively studied, the precise role of autophagy in cancer, especially in vivo, remains elusive and controversial. Moreover, targeting autophagy to treat cancer generally has not contributed significantly to the advancement of clinical trials. Therefore, identifying genetic vulnerability that renders strong sensitivity to autophagy inhibition is urgently needed to improve autophagy targeted- therapies. LKB1 regulates energy homeostasis by activating AMP-activated protein kinase (AMPK), which inhibits catabolic processes and upregulates anabolic processes, in response to energy crisis. Based on earlier studies, we began to test the hypothesis that loss of LKB1 promotes cancer cell proliferation but also restricts adaptation to metabolic stress, a property that may be further compromised by loss of autophagy. Using genetically engineered mouse models (GEMMs) of NSCLC, we found that autophagy inhibition was synthetically lethal in KrasG12D/+;Lkb1-/- (KL) mediated tumorigenesis; in contrast to KL lung tumors with intact autophagy, loss of an essential autophagy gene, Atg7, dramatically impaired both tumor initiation and tumor growth. This is in sharp contrast to wild-type LKB1 (KrasG12D/+;p53-/-) tumors that are much less sensitive to essential autophagy gene ablation. Our in vitro study further revealed that autophagy modulates lipid metabolism essential for KL cancer cells to survive nutrient starvation. These observations indicate that LKB1 mutations predispose KRAS- driven NSCLC to autophagy inhibition and that LKB1 mutations could be explored as a predictive biomarker for precision lung cancer therapy. Based on our recent findings, we form our central hypothesis: autophagy compensates for LKB1 loss by maintaining the metabolism of Lkb1-deficient Kras-driven lung tumors and promoting their metastasis. We will test this with following specific aims: Aim 1. Elucidate the mechanism by which autophagy regulates lipid metabolism and KL tumorigenesis in vivo. Aim 2. Determine how autophagy promotes KL tumor metastasis. Aim 3. Identify metabolic bypasses that potentially create resistance to autophagy inhibition in KL NSCLC. Successful completion of this proposal will: (1) yield new insights into the role of autophagy in modulating cellular metabolism in support of KL lung tumorigenesis and metastasis; (2) validate the novel concept that autophagy inhibition is a selective and powerful therapeutic strategy against primary and metastatic KL NSCLC; and (3) reveal metabolic bypass as a potential mechanism of therapy resistance.

摘要肺癌是癌症死亡的主要原因，其中非小细胞肺癌（NSCLC）占这些案件的85%以上。 KRAS 是 NSCLC 最常见的致癌驱动因素，具有预后不良，治疗选择有限。 LKB1 是 NSCLC 中第三个最常见的突变基因。这 KRAS 和 LKB1 突变约占 NSCLC 的 30%，且侵袭性增加，发病率高转移的频率和对治疗的抵抗力。自噬会降解蛋白质和细胞器回收它们以提供代谢底物，当细胞外营养物质有限时，这一功能至关重要。尽管自噬在癌症中的作用已得到深入研究，但自噬在癌症中的确切作用，尤其是在体内，仍然难以捉摸且存在争议。此外，普遍以自噬为靶点来治疗癌症并没有对临床试验的进展做出重大贡献。因此，识别遗传脆弱性迫切需要对自噬抑制具有很强的敏感性来改善自噬靶向疗法。 LKB1 通过激活 AMP 激活蛋白激酶 (AMPK) 来调节能量稳态，抑制分解代谢过程并上调合成代谢过程，以应对能源危机。基于之前的研究中，我们开始检验 LKB1 缺失会促进癌细胞增殖但也会限制这一假设对代谢应激的适应，这种特性可能会因自噬的丧失而进一步受到损害。使用在NSCLC基因工程小鼠模型（GEMM）中，我们发现自噬抑制是综合性的 KrasG12D/+ 致死；Lkb1-/- (KL) 介导的肿瘤发生；与具有完整自噬、缺失的 KL 肺肿瘤相比重要的自噬基因 Atg7 的缺失会显着损害肿瘤的发生和生长。这是在与对必需自噬不太敏感的野生型 LKB1 (KrasG12D/+;p53-/-) 肿瘤形成鲜明对比基因消融。我们的体外研究进一步揭示自噬调节脂质代谢对于 KL 至关重要癌细胞在营养饥饿中生存。这些观察结果表明 LKB1 突变易导致 KRAS- 驱动 NSCLC 自噬抑制，LKB1 突变可以作为预测性生物标志物进行探索肺癌精准治疗。根据我们最近的发现，我们形成了我们的中心假设：自噬通过维持 Lkb1 缺陷 Kras 驱动的肺部肿瘤的新陈代谢来补偿 LKB1 损失促进其转移。我们将通过以下具体目标对此进行测试：目标 1. 通过以下方式阐明机制：自噬调节体内脂质代谢和 KL 肿瘤发生。目标 2. 确定自噬如何进行促进KL肿瘤转移。目标 3. 识别可能产生耐药性的代谢旁路 KL NSCLC 中的自噬抑制。成功完成该提案将：(1) 产生对该角色的新见解自噬调节细胞代谢以支持 KL 肺肿瘤发生和转移； (2) 验证自噬抑制是针对原发性和自噬的一种选择性且有效的治疗策略的新概念转移性 KL 非小细胞肺癌； (3)揭示代谢旁路是治疗抵抗的潜在机制。