Targeting RNA Polymerase I Transcription Machinery in Chemoresistant Ovarian Cancer

靶向 RNA 聚合酶 I 转录机制治疗耐药卵巢癌

• 批准号: 10578755
• 负责人: Charles Nicholson Landen
• 金额: $ 49.38万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-03-01 至 2025-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10578755
• 关键词: Affect; Biogenesis; Biological Products; CRISPR library; Cancer cell line; Carboplatin; Cell Line; Cells; Cessation of life; Chemoresistance; Chromatin Structure; Clinical; Clinical Trials; Clustered Regularly Interspaced Short Palindromic Repeats; Cytotoxic agent; DNA; DNA Damage; DNA Polymerase I; Data; Dependence; Development; Disease Resistance; Dose; Epithelial ovarian cancer; Evolution; Genes; Genetic Transcription; Histology; Knock-out; Life; Maintenance Therapy; Malignant Neoplasms; Malignant neoplasm of ovary; Mediating; Microscopic; Modeling; Molecular; Non-Malignant; Paclitaxel; Pathway interactions; Patient Selection; Patients; Phase I/II Trial; Phenotype; Platinum; Population; Predisposition; Process; Production; Proliferating; RNA Polymerase I; RNA Polymerase Inhibitor; Recurrence; Resistance; Ribosomal Biogenesis Pathway; Ribosomal DNA; Ribosomal RNA; Ribosomes; Role; Sampling; Science; Site; Specificity; System; TP53 gene; Therapeutic; Therapeutic Effect; Translating; Tumor Debulking; Up-Regulation; biomarker identification; cancer cell; cancer subtypes; candidate identification; chemotherapy; combat; combinatorial; drug candidate; druggable target; efficacy evaluation; in vivo; in vivo Model; inhibitor; knock-down; next generation; novel; novel strategies; novel therapeutic intervention; patient derived xenograft model; phase I trial; pre-clinical; prevent; promoter; response; response biomarker; ribosome profiling; screening; side effect; small hairpin RNA; synergism; taxane; transcriptome; translatome; treatment response; tumor; virtual

PROJECT SUMMARY Virtually every cancer that takes the life of a patient is due to innate or acquired chemoresistance. This is especially true in epithelial ovarian cancer (EOC), in which most tumors are initially sensitive to platinum-based chemotherapy, but most will recur and succumb to chemoresistant disease. To achieve durable cures we must understand the molecular mechanisms of chemoresistance. Through in-depth analysis of multiple models of matched pre- and post-chemotherapy (carboplatin/paclitaxel) ovarian cancers from treated patients, patient- derived xenografts (PDX), and resistant cell lines, we have discovered and validated that chemoresistant tumors have significant upregulation of the ribosomal biogenesis pathway. We have further examined efficacy of two inhibitors of RNA Polymerase I (Pol I), the primary regulator of rRNA production. These agents, CX-5461 and BMH-21, have significant (but frequently variable) activity against ovarian cancer cell lines and PDX models of all histologies, and in many cases is even more effective in chemoresistant models. CX-5461 is currently in a phase I trial, but we are the first to demonstrate and explore the particular susceptibility of chemoresistant cells to targeting ribosomal biogenesis, and why this process might be key to developing chemoresistance. Several questions remain unanswered, including whether targeting Pol I can kill the post-chemo microscopic remaining population to achieve durable cures; how upregulation of ribosomal machinery enhances chemoresistance; what transcriptome is activated by chemotherapy; whether the effects are specific to paclitaxel, carboplatin, or the combination; and whether the hypothesized critical role of TP53 in the efficacy of these agents can allow strategies to allow targeting Pol I to be even more effective. The overall objectives of this proposal are to understand how upregulation of ribosome biogenesis allows cancer cells to survive chemotherapy, identify the most effective setting in which to target Pol I as a therapy, and identify the best agents to use in combination with Pol I for therapeutic synergy. To achieve these objectives, we will investigate in greater detail the chemotherapy-induced differences in ribosome synthesis between the chemosensitive and chemoresistant cell populations using multiple models, and identify how these differences are mediating Pol I inhibitor sensitivity. Chemoresistant PDX models will be used to determine if Pol I targeting can prevent recurrence, or enhance carbo/paclitaxel efficacy. We will investigate the differences between chemosensitive and chemoresistant cells at the level of chromatin structure, occupancy of rRNA DNA transcription sites, and ribosomal organization. We will utilize a 7,000-gene CRISPR library of druggable targets to identify candidate drugs to use in combination with targeting Pol I. If the role of ribosomal biogenesis in chemoresistant cells can be better understood, it could open the door to an entirely new approach to treating many cancers, and focus on the most deadly aspect of cancer – evolution to a chemoresistant phenotype for which there is no cure.

项目概要 事实上，每一种夺去患者生命的癌症都是由于先天或后天的化疗耐药性造成的。这 在上皮性卵巢癌 (EOC) 中尤其如此，其中大多数肿瘤最初对铂类药物敏感 化疗，但大多数会复发并死于化疗耐药性疾病。为了实现持久治疗，我们必须 了解化学耐药性的分子机制。通过对多个模型的深入分析 来自接受治疗的患者的匹配的化疗前和化疗后（卡铂/紫杉醇）卵巢癌，患者- 衍生异种移植物（PDX）和耐药细胞系，我们发现并验证了化疗耐药肿瘤 对核糖体生物发生途径有显着上调。我们进一步检验了两种方法的功效 RNA 聚合酶 I (Pol I) 的抑制剂，RNA 聚合酶 I 是 rRNA 产生的主要调节因子。这些药物，CX-5461 和 BMH-21，对卵巢癌细胞系和 PDX 模型具有显着（但经常变化）的活性 所有组织学，并且在许多情况下在化疗模型中甚至更有效。 CX-5461 目前处于 I 期试验，但我们是第一个证明和探索化疗耐药细胞的特殊敏感性的人 靶向核糖体生物发生，以及为什么这个过程可能是产生化疗耐药性的关键。一些 问题仍未得到解答，包括靶向 Pol I 是否可以杀死化疗后残留的显微镜下的细菌 人口实现持久治疗；核糖体机制的上调如何增强化疗耐药性；什么 转录组被化疗激活；这些效应是否是紫杉醇、卡铂或紫杉醇所特有的 组合; TP53 在这些药物功效中的假设关键作用是否可以允许 使针对 Pol I 的目标更加有效的策略。该提案的总体目标是 了解核糖体生物合成的上调如何使癌细胞能够在化疗中存活下来，确定 以 Pol I 作为治疗目标的最有效环境，并确定联合使用的最佳药物 与 Pol I 具有协同治疗作用。为了实现这些目标，我们将更详细地调查 化疗引起的化疗敏感细胞和化疗耐药细胞之间核糖体合成的差异 使用多个模型对人群进行研究，并确定这些差异如何调节 Pol I 抑制剂敏感性。 耐药 PDX 模型将用于确定 Pol I 靶向是否可以预防复发或增强 卡博/紫杉醇功效。我们将研究化疗敏感细胞和化疗耐药细胞之间的差异 在染色质结构、rRNA DNA 转录位点的占据和核糖体组织水平上。我们 将利用 7,000 个基因的 CRISPR 药物靶点文库来确定联合使用的候选药物 如果可以更好地理解核糖体生物发生在化疗耐药细胞中的作用，那么它可以 打开了治疗许多癌症的全新方法的大门，并专注于最致命的方面 癌症——进化为无法治愈的化疗耐药表型。