Biology of R-Spondin-Induced Sensitization to Asparaginase in Colorectal Cancer

R-Spondin 诱导结直肠癌天冬酰胺酶敏感性的生物学

• 批准号: 10434148
• 负责人: LUKAS Edward DOW
• 金额: $ 61.87万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10434148
• 关键词: Address; Alleles; Amino Acids; Asparagine; Biology; Cancer Etiology; Cell physiology; Cells; Cessation of life; Clinical; Clinical Trials; Colorectal Cancer; Data; Development; Disease; Drug resistance; Engineering; Epithelial Cells; Event; Generations; Genetic Engineering; Genetic Screening; Genetically Engineered Mouse; Hematopoietic; Human; Hypersensitivity; Immunotherapy; Impairment; Intestines; KRAS oncogenesis; KRAS2 gene; Knowledge; Life; Ligands; Maps; Mediating; Modeling; Molecular; Mus; Mutation; Oncogenic; Organoids; Outcome; Pathway interactions; Patients; Pharmacology; Phase; Proteins; Resistance; Role; Series; Signal Transduction; Source; Starvation; System; TP53 gene; Testing; Therapeutic; Therapeutic Index; Therapeutic Intervention; Toxic effect; Translating; Ubiquitin; Ubiquitination; WNT Signaling Pathway; asparaginase; base; beta catenin; bone; cancer cell; colon cancer cell line; colorectal cancer treatment; effective therapy; genome-wide; improved; inhibitor; innovation; insight; leukemia; mortality; mouse model; multicatalytic endopeptidase complex; predictive modeling; progenitor; prospective; protein activation; protein degradation; rational design; receptor; response; syndecan; targeted treatment; therapy resistant; treatment response; tumor

ABSTRACT Colorectal cancer (CRC) is the second-leading cause of cancer deaths in the US, and unlike many other tumor types, there are no known effective therapies targeting dominant oncogenic drivers. Almost all CRCs have mutations that activate canonical Wnt/β-catenin signaling, but direct inhibition of β-catenin is difficult, and blocking Wnt ligand activity leads to significant on-target bone toxicity. Thus, while targeting Wnt directly is challenging, aberrant Wnt pathway activation may induce tumor-specific vulnerabilities that can be exploited for CRC therapy. Using a genome-wide genetic screen, we found that Wnt activation induces profound sensitization to therapeutic asparagine depletion using asparaginase in drug-resistant leukemias. This effect is dependent on Wnt-induced inhibition of GSK3, but is independent of APC or β-catenin. Instead, asparaginase sensitization is mediated by Wnt-induced inhibition of GSK3-dependent protein degradation, a catabolic source of amino acids required for asparaginase resistance. CRC provides a unique context in which to test predictions from our model, because these tumors almost all have mutations that activate Wnt/β-catenin, but these can function either upstream or downstream of GSK3. Using human CRC cell lines and genetically engineered mouse intestinal organoids, we found that asparaginase had little effect on CRCs with mutations of the downstream Wnt factor APC, but was profoundly toxic to cases with R-spondin translocations, which activate Wnt signaling via ligand-induced inhibition of GSK3, and thus inhibit GSK3-dependent protein degradation. Importantly, this approach has little detectable toxicity to normal intestinal or epithelial cells. This suggests that this approach has a potent therapeutic index that could transform clinical outcomes for the thousands of patients who die of CRC every year, and a clinical trial based on these data is under development. However, we do not understand key aspects of the biology underlying this RSPO/Wnt-induced therapeutic vulnerability. Defining the precise molecular events that dictate RSPO/Wnt induced asparaginase sensitivity is critical for prospectively identifying clinical responders, designing rational approaches to improve therapeutic response, and overcoming treatment resistance. These knowledge gaps will be addressed in the following Aims: 1) Determine how RSPO ligands induce sensitization to asparaginase. 2) Investigate the role of GSK3α body formation as a cellular response to asparagine starvation. 3) Determine the role of oncogenic KRAS and TP53 mutations in therapeutic response of RSPO fusion CRC to asparaginase. This proposal is expected to provide fundamental insights into the amino acid starvation response and its impairment by aberrant Wnt signaling, cellular processes fundamental to metazoan life whose molecular basis and therapeutic exploitation remain poorly understood. Given our highly complementary expertise in asparaginase biology and Wnt signaling, this MPI team is uniquely poised to translate these advances into highly innovative therapeutic interventions.

抽象的 结直肠癌（CRC）是美国癌症死亡的第二大原因，与许多其他肿瘤不同 类型，尚无针对主导性致癌驱动因素的已知有效疗法。几乎所有CRC都有 激活规范Wnt/β-catenin信号但直接抑制β-catenin的突变很难，并且很困难，并且 阻断Wnt配体活性会导致明显的目标骨毒性。那时，直接针对wnt是 具有挑战性的，异常的Wnt途径激活可能会引起肿瘤特异性漏洞 CRC疗法。使用全基因组遗传筛选，我们发现Wnt激活诱导了深刻的 在抗药性白血病中使用天冬酰胺酶对治疗性天冬酰胺定义的敏感。这种效果是 取决于Wnt诱导的GSK3抑制作用，但与APC或β-catenin无关。相反，天冬氨酸酶 敏化是由Wnt诱导的GSK3依赖性蛋白降解的抑制（一种分解代谢源）介导的 天冬氨酸酶耐药性所需的氨基酸。 CRC提供了一个独特的环境来测试 来自我们模型的预测，因为这些肿瘤几乎都具有激活Wnt/β-catenin的突变，但是 这些可以在GSK3的上游或下游功能。使用人类CRC细胞系，一般 设计的小鼠肠道器官，我们发现天冬酰胺酶对CRC的影响很小 下游Wnt因子APC，但对R-Spondin易位的病例具有深刻的毒性，该病例是 通过配体诱导的GSK3抑制激活Wnt信号，从而抑制GSK3依赖性蛋白 降解。重要的是，这种方法对正常肠道或上皮细胞几乎没有可检测到的毒性。 表明这种方法具有潜在的治疗指数，可以改变 每年数千名死于CRC的患者，以及基于这些数据的临床试验 发展。但是，我们不理解该RSPO/WNT引起的生物学的关键方面 治疗脆弱性。定义决定RSPO/WNT诱导天冬酰胺酶的精确分子事件 敏感性对于前瞻性识别临床响应者而设计合理的方法至关重要 治疗反应和克服治疗抗性。这些知识差距将在 以下目的：1）确定RSPO配体如何诱导天冬酰胺酶的敏感性。 2）调查角色 GSK3α体的形成是对天冬酰胺饥饿的细胞反应。 3）确定致癌的作用 RSPO融合CRC对天冬酰胺酶的理论反应中的KRAS和TP53突变。该提议是 预计将提供对氨基酸饥饿反应及其损害的基本见解 异常的Wnt信号传导，分子基础和 治疗性剥削仍然知之甚少。鉴于我们在天冬酰胺酶方面的高档专业知识 生物学和WNT信号传导，该MPI团队被毒死了，可以将这些进步转化为高度创新的 治疗干预措施。