Metabolic modulation of alkylating agent efficacy in MEK inhibitor resistant thyroid cancers.

MEK 抑制剂耐药性甲状腺癌中烷化剂功效的代谢调节。

• 批准号: 10675021
• 负责人: Ioanna Papandreou
• 金额: $ 18.04万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10675021
• 关键词: Acute; Address; Adipose tissue; Alkylating Agents; Amino Acids; BRAF gene; Biochemical; Biological Assay; Biological Markers; Bioluminescence; Cancer Model; Cancer Patient; Cancer cell line; Cell Line; Cell physiology; Cells; Cellular Stress; Clinical; Clustered Regularly Interspaced Short Palindromic Repeats; Compensation; DNA Repair Enzymes; Data; Dependence; Down-Regulation; Engineering; Epigenetic Process; Evolution; Gene Expression Profile; Genetic; Glucose; Growth; Ifosfamide; In Vitro; In complete remission; Intervention; Lipase; Lipids; Lipolysis; Lomustine; MAP Kinase Gene; MAP2K1 gene; MEK inhibition; MEKs; MGMT gene; Malignant Neoplasms; Malignant neoplasm of thyroid; Measures; Membrane Biology; Messenger RNA; Metabolic; Metabolic Pathway; Metabolism; Methylation; Modeling; Molecular; Mus; Mutation; Nutritional Requirements; Oncogenes; Oncogenic; Organelles; Papillary thyroid carcinoma; Pathway interactions; Population; Pre-Clinical Model; Process; Proteins; Quantitative Reverse Transcriptase PCR; Refractory; Regulation; Relapse; Reporter; Resistance; Role; Signal Transduction; Signaling Molecule; Sorting; Stress; System; Testing; Thyroid Gland; Triglycerides; Tumor Promotion; Tumor-Derived; Western Blotting; Work; Xenograft procedure; anaplastic thyroid cancer; cancer cell; candidate identification; cell transformation; clinical application; cytotoxic; drug efficacy; efficacy evaluation; experimental study; genetic manipulation; improved; in vitro Model; in vivo; in vivo Model; inhibitor; kinase inhibitor; lipid metabolism; melanoma; membrane synthesis; novel; overexpression; pharmacologic; programs; promoter; protective pathway; protein protein interaction; protein transport; resistance mechanism; response; subcutaneous; success; targeted treatment; temozolomide; therapeutic target; therapy outcome; therapy resistant; transcriptome sequencing; translational potential; tumor; tumor growth; tumor heterogeneity; tumor microenvironment; tumor progression

PROJECT SUMMARY Anaplastic thyroid cancer (ATC) is a lethal entity characterized by frequent mutations in the BRAF oncogene. Until recently there were no treatment options to substantially prolong survival in ATC patients. Unlike BRAFV600E- driven melanomas, thyroid cancers with BRAFV600E mutations are only modestly responsive to targeted kinase inhibitor monotherapy, which emphasizes the significant context dependent differences in the molecular mechanisms that compensate for oncogenic signaling blockade. The recent approval of dual BRAF + MEK inhibition is a critical addition to the arsenal against advanced ATC, with results showing improved tumor control. Despite the initial success of targeted therapies, acquisition of resistance and relapse occur frequently and severely limit complete responses and cures. Such therapy-induced adaptive mechanisms include the rewiring of metabolic pathways that protect from BRAF pathway inhibition, however, it is not known if metabolic alterations occur in ATCs during the evolution of acquired resistance and if they have any potential clinical utility. In preliminary experiments we found that MEK inhibitors induce lipolysis and lipid droplet (LD) loss in ATC cells. LD are dynamic organelles participating in crucial cellular functions including metabolism, protein trafficking, membrane synthesis and signaling. We generated in vitro models of acquired resistance to MEK inhibitors with re-established LD abundance and analyzed their gene expression patterns to identify candidate vulnerabilities that can be pharmacologically targeted with clinically approved therapies. We found that expression of the DNA repair enzyme MGMT was downregulated in LDhigh but not LDlow MEK inhibitor resistant (MEKiR) clones. Here we propose to rigorously evaluate the hypothesis that LD abundance and MGMT expression can serve as biomarkers indicating alkylating agent sensitivity in preclinical models of MEKi resistant thyroid cancers. In aim 1 we will identify metabolic determinants of MGMT expression in MEKiR by uncovering nutritional requirements and epigenetic marks that control MGMT expression and sensitivity to alkylating agents. We will engineer isogenic cell lines with perturbed expression of the rate limiting triglyceride lipase ATGL/PNPLA2 to ask if LD accumulation is necessary or sufficient for MGMT silencing, and will assess if protein- protein interactions regulate ATGL activity in MEKiR. In aim 2 we will quantify the efficacy of alkylating agents in xenotransplanted MEKiR model tumors. Further, we will generate novel in vivo preclinical models of MEKi resistance by intermittent trametinib treatment of tumors in mice, and will validate LD abundance as a biomarker for alkylating agent efficacy by determining tumoral LD turnover, MGMT expression and response to alkylating agent therapy in these tumors.

项目概要 甲状腺未分化癌 (ATC) 是一种致命实体，其特征是 BRAF 癌基因频繁突变。 直到最近，还没有任何治疗方案可以显着延长 ATC 患者的生存期。与BRAFV600E不同- 具有 BRAFV600E 突变的黑色素瘤、甲状腺癌对靶向激酶仅有适度反应 抑制剂单一疗法，强调分子中显着的背景依赖性差异 补偿致癌信号传导阻断的机制。近期批准双BRAF+MEK 抑制是对抗先进 ATC 的重要补充，结果显示肿瘤控制得到改善。 尽管靶向治疗取得了初步成功，但耐药性和复发频繁发生， 严重限制了完全的反应和治愈。这种治疗诱导的适应性机制包括重新布线 保护免受 BRAF 途径抑制的代谢途径，然而，尚不清楚代谢途径是否 在获得性耐药的进化过程中，ATC 会发生变化，并且它们是否具有任何潜在的临床用途。 在初步实验中，我们发现 MEK 抑制剂会诱导 ATC 细胞中的脂肪分解和脂滴 (LD) 损失。 LD 是参与关键细胞功能的动态细胞器，包括新陈代谢、蛋白质运输、 膜合成和信号传导。我们生成了 MEK 抑制剂获得性耐药的体外模型 重新建立 LD 丰度并分析其基因表达模式以确定候选漏洞 可以通过临床批准的疗法进行药理学靶向。我们发现DNA的表达 修复酶 MGMT 在 LDhigh 克隆中下调，但在 LDlow MEK 抑制剂抗性 (MEKiR) 克隆中未下调。 在这里，我们建议严格评估 LD 丰度和 MGMT 表达可以服务的假设 作为 MEKi 耐药性甲状腺临床前模型中指示烷化剂敏感性的生物标志物 癌症。在目标 1 中，我们将通过揭示 MEKiR 中 MGMT 表达的代谢决定因素 控制 MGMT 表达和对烷化剂敏感性的营养需求和表观遗传标记。 我们将设计具有扰动的限速甘油三酯脂肪酶表达的同基因细胞系 ATGL/PNPLA2 询问 LD 积累对于 MGMT 沉默是否必要或充分，并将评估蛋白质是否 蛋白质相互作用调节 MEKiR 中的 ATGL 活性。在目标 2 中，我们将量化烷化剂在以下方面的功效： 异种移植 MEKiR 模型肿瘤。此外，我们将生成 MEKi 的新型体内临床前模型 通过间歇性曲美替尼治疗小鼠肿瘤来发现耐药性，并将验证 LD 丰度作为生物标志物 通过测定肿瘤 LD 转换、MGMT 表达和对烷化剂的反应来确定烷化剂的功效 这些肿瘤的药物治疗。