Identifying Novel Intensity-Specific Regulators of RAS Signaling

鉴定 RAS 信号传导的新型强度特异性调节因子

• 批准号: 10668217
• 负责人: Zahra Kabiri
• 金额: $ 13.27万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-19 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10668217
• 关键词: Biochemistry; CRISPR/Cas technology; Cancer Biology; Cancer cell line; Cells; Codon Nucleotides; Disease; Drosophila genus; Eye; Family; Family member; Feedback; Frequencies; Genes; Genetic; Genetic Predisposition to Disease; Genetically Engineered Mouse; Goals; Growth; Homologous Gene; Human; KRAS2 gene; Libraries; Link; MAP Kinase Gene; Malignant Neoplasms; Mammalian Cell; Maps; Mediating; Medicine; Messenger RNA; Monitor; Monomeric GTP-Binding Proteins; Mutate; Mutation; Oncogenic; Output; Pathology; Pathway interactions; Phenotype; Positioning Attribute; Post-Transcriptional Regulation; Protein Subunits; Proteins; RAS driven cancer; RAS genes; RNA Interference; RNA-Binding Proteins; Regulation; Research; Research Personnel; Ribosomal Proteins; Ribosomes; Role; Signal Transduction; Testing; Therapeutic Intervention; Time; Translations; Tumor Promotion; Tumor Suppressor Proteins; biological adaptation to stress; cancer initiation; cancer therapy; candidate identification; clinically relevant; experience; fascinate; fly; gene discovery; in vivo; knock-down; mRNA Stability; mRNA Translation; malignant phenotype; multidisciplinary; mutant; new therapeutic target; novel; novel strategies; novel therapeutics; ras Proteins; response; risk prediction; screening; senescence; stem cell biology; therapeutic target; therapy resistant; tumor initiation; tumor progression; tumorigenesis; whole genome

Abstract The mammalian family of RAS small GTPases, composed of HRAS, NRAS, and KRAS, is mutated to remain in an active, oncogenic state in one fifth of all human cancers. Typically, these mutations occur early, initiating tumorigenesis. Of the three family members, KRAS is mutated most often, suggesting that some feature of this gene renders it more likely to initiate tumorigenesis. To this end, our group linked the high frequency with which KRAS is mutated to a bias of rare codons and resulting poor translation of the encoded mRNA. Mechanistically, the lower levels of KRAS protein and KRAS/MAPK signaling intensity circumvent the growth arrest response of senescence, thereby allowing the induction of tumor initiation. Conversely, poor translation of KRAS mRNA is overcome in later disease stages, promoting tumor progression. Thus, different levels of KRAS/MAPK signaling intensity dictate distinct phenotypic outputs during cancer initiation and progression. Therefore, there must be factors that differentially control Ras signaling intensity, and these factors should be critical during either tumor initiation or tumor progression. Such regulators are of great clinical relevance and could open up the door to a whole new class of regulators of Ras signaling for therapeutic intervention. My long-term goal is to identify and therapeutically target “RAS intensity-specific regulators”. To identify these regulators, our group took advantage of the incredible sensitivity of the Drosophila rough eye phenotype to differential levels of Ras signaling. We employed the novel approach of altering codon usage in the Ras gene of Drosophila to compare high and low Ras signaling. We then exploited these two genetic backgrounds to execute the first-ever in vivo intensity-specific regulator screen and identified fifteen deficiencies. One deficiency was mapped to the Ribosomal protein S21 (Rps21) gene, which acts as a suppressor of Ras signaling. I therefore plan to investigate the underlying mechanism by which Rps21 suppresses Ras signaling (Aim 1). In addition, I aim to identify other novel intensity-specific regulators of Ras signaling in the remaining deficiencies and elucidate their roles in Ras tumorigenesis in the mammalian setting (Aim 2). Completion of these aims will establish new connections between translational control and Ras signaling, reveal new genetic vulnerabilities in RAS-driven cancer, and finally could unearth a pipeline of potential therapeutic targets to explore for cancer therapies.

抽象的 哺乳动物 RAS 小 GTP 酶家族由 HRAS、NRAS 和 KRAS 组成，经过突变后仍保留在 五分之一的人类癌症处于活跃的致癌状态。通常，这些突变发生得很早，引发 肿瘤发生。在这三个家族成员中，KRAS 突变最频繁，这表明该家族的某些特征 基因使其更有可能引发肿瘤发生。为此，我们小组将高频与 KRAS 突变为稀有密码子，导致编码的 mRNA 翻译不良。从机械上来说， 较低水平的 KRAS 蛋白和 KRAS/MAPK 信号强度规避了生长停滞反应 衰老，从而诱导肿瘤发生。相反，KRAS mRNA 的翻译不良是 在疾病后期克服，促进肿瘤进展。因此，不同水平的 KRAS/MAPK 信号传导 强度决定了癌症发生和进展过程中不同的表型输出。因此，必须有 差异控制 Ras 信号强度的因素，这些因素在任一肿瘤发生过程中都至关重要 肿瘤的发生或进展。这样的监管机构具有很大的临床意义，并可能打开大门 用于治疗干预的全新 Ras 信号调节因子。我的长期目标是确定 并针对“RAS 强度特异性调节因子”进行治疗。为了识别这些监管机构，我们的小组采取了 利用果蝇粗眼表型对 Ras 不同水平的令人难以置信的敏感性 发信号。我们采用改变果蝇 Ras 基因密码子使用的新方法来比较 高和低 Ras 信号。然后，我们利用这两种遗传背景进行了首次体内实验 强度特定调节器筛选并确定了十五个缺陷。一项缺陷被映射到 核糖体蛋白 S21 (Rps21) 基因，充当 Ras 信号传导的抑制因子。因此我打算调查一下 Rps21 抑制 Ras 信号传导的潜在机制（目标 1）。此外，我的目标是确定其他 Ras 信号传导的新型强度特异性调节剂解决了其余缺陷，并阐明了它们在 Ras 中的作用 哺乳动物肿瘤发生（目标 2）。完成这些目标将建立新的联系 翻译控制和 Ras 信号传导之间的关系，揭示 RAS 驱动的癌症中新的遗传脆弱性，以及 最终可以挖掘出一系列潜在的治疗靶点来探索癌症疗法。