Target discovery and combination therapy in KRAS mutant cancer

KRAS突变癌症的靶点发现和联合治疗

• 批准号: 10702641
• 负责人: Ji Luo
• 金额: $ 47.35万
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10702641
• 关键词: Anchorage-Independent Growth; Attention; CRISPR/Cas technology; Cancer Patient; Cancer cell line; Cells; Clinical Trials; Colorectal; Colorectal Cancer; Combined Modality Therapy; Dependence; Development; Drug Combinations; Drug Targeting; Drug resistance; Drug toxicity; Epithelial Cells; Genes; Genetic; Genetic Screening; Genetic Transcription; Goals; KRAS2 gene; Lead; Libraries; Lung; MAP Kinase Gene; MEKs; Malignant Neoplasms; Malignant neoplasm of lung; Malignant neoplasm of pancreas; Modality; Modeling; Multiple Myeloma; Mus; Oncogenes; Oncogenic; Outcome; Pancreas; Pathway interactions; Patients; Pharmacology; Pre-Clinical Model; Resistance; Signal Transduction; Stress; Therapeutic; Xenograft procedure; cancer cell; driver mutation; functional genomics; high-throughput drug screening; improved; in vivo; inhibitor; kinase inhibitor; loss of function; mutant; new therapeutic target; novel drug combination; novel therapeutics; oncogene addiction; prevent; ras Oncogene; resistance mechanism; response; small molecule inhibitor; targeted treatment; tool; treatment response; tumor

BACKGROUND. The KRAS oncogene is a driver mutation in a significant fraction of lung, pancreatic and colorectal cancers. Recently breakthroughs with inhibitors targeting the KRAS-G12C mutant is the first Ras targeted therapies in decades. For other KRAS mutant tumors, there are no effective targeted therapies. Resistance to KRAS inhibitors develop rapidly in cancer patients, and drug combination that can prevent or delay drug resistant are needed to extend the durability of response in patients. In addition to Ras, kinases inhibitors against Ras effector pathways have been developed to target the MAPK and PI3K pathways. However, these agents have not demonstrated efficacy in clinical trials against KRAS mutant tumors. Thus far, targeted therapies have primarily focused on blocking OA, and less attention have been devoted to blocking NOA in KRAS mutant cells. Co-targeting NOA and OA together could lead to better drug combinations with orthogonal therapeutic modalities, improved therapeutic window, and more durable response in KRAS mutant tumors. OBJECTIVES. 1) Using functional genomic screens to identify genetic dependencies resulting from oncogene addiction (OA) and non-oncogene addiction (NOA) in KRAS mutant cancer cells; 2) Evaluating the mechanism, selectivity of targeted therapies in KRAS mutant cells, and the mechanisms leading to drug resistance; and 3) Identify drug combinations that orthogonally target distinct aspects of OA and NOA in KRAS mutant cells to achieve better therapeutic window. MAJOR ACTIVITIES, SIGNIFICANT RESULTS AND KEY OUTCOMES. 1) Genetic screens to identify functional vulnerabilities in KRAS mutant cancer cells. Using pooled CRISPR/Cas9 gene KO libraries, we have carried out loss-of-function screens in KRAS mutant cancer cells under different culture conditions. We have identified a candidate, druggable gene that is critical for the anchorage-independent growth of KRAS mutant cells, and we are currently investigating the mechanism of this genetic dependency and exploring small molecule inhibitors of this target. 2) Mechanisms of drug resistant to Ras pathway inhibitors. Using different KRAS mutant cancer cell lines including colorectal, pancreatic, lung, and multiple myeloma cells, we have evaluated genetic and post-transcriptional mechanisms that contribute to resistance to KRAS inhibitors and MEK inhibitors. We are currently elucidating how these resistance mechanisms can be reversed to improve therapeutic response in pre-clinical models. 3) Identification of novel drug combinations for KRAS mutant cancer. Using high-throughput drug screen and hypothesis-driven approach, we are evaluating drug combinations that involve inhibitors targeting Ras OA to block oncogenic Ras signaling and inhibitors targeting NOA pathways to exacerbate oncogenic stress in KRAS mutant cancer cells. We contrast the toxicity of drug combinations in KRAS mutant cancer cells against that in normal epithelial cells to assess the therapeutic window, and we use mouse xenograft and autochthonous tumor models to evaluate the drug combination's efficacy against KRAS-driven tumors in vivo.

背景。KRAS癌基因在很大一部分肺癌、胰腺癌和结直肠癌中是一种驱动突变。最近针对KRAS-G12C突变体的抑制剂的突破是几十年来第一个Ras靶向治疗。对于其他KRAS突变肿瘤，尚无有效的靶向治疗方法。癌症患者对KRAS抑制剂的耐药性迅速发展，需要能够预防或延迟耐药的药物组合来延长患者的反应持久性。除Ras外，针对Ras效应通路的激酶抑制剂已被开发用于靶向MAPK和PI3K通路。然而，这些药物尚未在临床试验中证明对KRAS突变肿瘤有效。到目前为止，靶向治疗主要集中于阻断OA，而对KRAS突变细胞中阻断NOA的关注较少。共同靶向NOA和OA可以在KRAS突变肿瘤中获得更好的药物组合和正交治疗方式，改善治疗窗口和更持久的反应。目标。1)利用功能基因组筛选鉴定KRAS突变癌细胞中癌基因成瘾（OA）和非癌基因成瘾（NOA）导致的遗传依赖性；2)评价靶向治疗KRAS突变细胞的机制、选择性以及导致耐药的机制；3)确定正交靶向KRAS突变细胞OA和NOA不同方面的药物组合，以获得更好的治疗窗口。主要活动、重要成果和关键成果。1)基因筛选鉴定KRAS突变癌细胞的功能脆弱性。利用汇集的CRISPR/Cas9基因KO文库，我们在不同培养条件下对KRAS突变癌细胞进行了功能丧失筛选。我们已经确定了一个候选的可药物基因，它对KRAS突变细胞的锚定非依赖性生长至关重要，我们目前正在研究这种遗传依赖性的机制，并探索该靶点的小分子抑制剂。2) Ras通路抑制剂的耐药机制。使用不同的KRAS突变癌细胞系，包括结直肠癌、胰腺癌、肺癌和多发性骨髓瘤细胞，我们评估了导致KRAS抑制剂和MEK抑制剂耐药的遗传和转录后机制。我们目前正在阐明如何在临床前模型中逆转这些耐药机制以改善治疗反应。3) KRAS突变型癌症的新药物组合鉴定。使用高通量药物筛选和假设驱动的方法，我们正在评估药物组合，包括靶向Ras OA的抑制剂来阻断致癌Ras信号传导和靶向NOA途径的抑制剂来加剧KRAS突变癌细胞的致癌应激。我们对比了药物组合对KRAS突变癌细胞的毒性和对正常上皮细胞的毒性来评估治疗窗口，并使用小鼠异种移植和原位肿瘤模型来评估药物组合对体内KRAS驱动肿瘤的疗效。