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: 10350724
• 负责人: Zahra Kabiri
• 金额: $ 13.39万
• 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/10350724
• 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; Genetic Translation; 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 genes; RNA Interference; RNA-Binding Proteins; Regulation; Research; Research Personnel; Ribosomal Proteins; Ribosomes; Risk; Role; Signal Transduction; Testing; Therapeutic Intervention; Time; Translations; Tumor Suppressor Proteins; biological adaptation to stress; cancer initiation; cancer therapy; clinically relevant; experience; fascinate; fly; gene discovery; in vivo; knock-down; mRNA Stability; malignant phenotype; multidisciplinary; mutant; new therapeutic target; novel; novel strategies; novel therapeutics; ras Proteins; response; 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.

摘要 由HRAS、NRAS和KRAS组成的RAS小GTP酶的哺乳动物家族被突变以保持在 五分之一的人类癌症都处于活跃的致癌状态。通常，这些突变发生在早期， 肿瘤发生在这三个家族成员中，KRAS最常发生突变，这表明KRAS的某些特征可能与其基因突变有关。 基因使其更有可能启动肿瘤发生。为此，我们的小组将高频率与 KRAS突变为稀有密码子的偏好，并导致编码的mRNA翻译不良。机械地说， 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，从而允许诱导肿瘤起始。相反，KRAS mRNA的翻译差是 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 强度决定了癌症起始和进展期间不同的表型输出。因此，必须 差异控制Ras信号强度的因素，这些因素在任何肿瘤发生过程中都是关键的。 开始或肿瘤进展。这种调节剂具有很大的临床相关性，可以打开大门， 一种全新的Ras信号调节剂，用于治疗干预。我的长期目标是找出 和治疗靶点“RAS强度特异性调节剂”。为了确定这些监管机构，我们的团队采取了 果蝇粗糙眼表型对Ras差异水平的难以置信的敏感性的优势 发信号。我们采用了改变果蝇Ras基因密码子使用的新方法， 高和低Ras信号传导。然后，我们利用这两种遗传背景， 强度特定的调节器屏幕，并确定了十五个缺陷。一个缺陷被映射到 核糖体蛋白S21（Rps 21）基因，其作为Ras信号传导的抑制剂。因此我打算调查 Rps 21抑制Ras信号传导的潜在机制（目的1）。此外，我还想找出其他 新的强度特异性调节Ras信号在其余的缺陷，并阐明其作用Ras 在哺乳动物环境中的肿瘤发生（目的2）。这些目标的实现将建立新的联系 翻译控制和Ras信号之间的联系，揭示RAS驱动的癌症中新的遗传脆弱性， 最终可以挖掘出一系列潜在的治疗靶点，以探索癌症治疗方法。