FEN1 Endonuclease as a Synthetic Lethal Target for Cancer Therapy

FEN1 核酸内切酶作为癌症治疗的合成致死靶点

• 批准号: 10294863
• 负责人: Olivier Harismendy
• 金额: $ 63.95万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-15 至 2026-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10294863
• 关键词: Ablation; Affect; Antineoplastic Agents; BRCA1 Mutation; BRCA1 gene; BRCA2 Mutation; BRCA2 gene; Base Excision Repairs; Biological Assay; Biological Models; Breast Cancer cell line; Breast Cancer therapy; Cancer cell line; Cell Line; Cells; Chromosomal Rearrangement; Chromosome Breakage; Chromosomes; Clustered Regularly Interspaced Short Palindromic Repeats; Colorectal Cancer; DNA; DNA biosynthesis; DNA replication fork; DNA sequencing; Data; Defect; Dependence; Development; Diploid Cells; Double Strand Break Repair; Dropout; Drug Targeting; Engineering; Epigenetic Process; Essential Genes; Evaluation; Evolution; Frequencies; Genes; Genetic; Genetic study; Genomic DNA; Genomic Instability; Genomics; Germ-Line Mutation; Goals; Guide RNA; Hereditary Breast and Ovarian Cancer Syndrome; Homologous Gene; Human; Human Genome; Hypersensitivity; In Vitro; Informatics; Inherited; Knock-out; Knowledge; Laboratories; Lethal Genes; Libraries; Maintenance Therapy; Malignant - descriptor; Malignant Neoplasms; Malignant neoplasm of ovary; Measures; Metaphase; Mining; Mus; Mutate; Mutation; Okazaki fragments; PARP inhibition; Pathway Analysis; Pharmacology; Process; Progression-Free Survivals; RTH-1 Nuclease; Research; Resistance; Screening Result; Small Interfering RNA; Specificity; Suppressor Genes; Testing; Therapeutic Agents; Validation; Yeasts; base; brca gene; cancer cell; cancer genome; cancer genomics; cancer therapy; cancer type; candidate selection; candidate validation; endonuclease; genome integrity; genome-wide; homologous recombination; improved; in silico; in vivo; inhibitor/antagonist; knock-down; malignant breast neoplasm; mutant; nuclease; predictive signature; recombinational repair; replication stress; resistance mechanism; response; small molecule; targeted cancer therapy; therapeutic development; therapeutic target; therapy design; transcriptomics; tumor xenograft; validation studies; yeast genetics; yeast genome

PROJECT SUMMARY Gross chromosomal rearrangements (GCRs), a type of genome instability, are often seen in inherited and sporadic cancers and are an important driver of malignant progression. For example, hereditary breast and ovarian cancers resulting from BRCA1 and BRCA2 germline mutations suffer from homologous recombination repair (HRR) defects that increase GCRs in model systems. Our previous studies have established a comprehensive network of genome instability suppressor (GIS) genes in yeast and demonstrated in silico that human homologs of these yeast GIS genes are genetically and/or epigenetically altered across many cancer types. From yeast genetic studies, we have also identified and rank-ordered synthetic lethal (SL) partners of non-essential GIS genes. The feasibility of targeting SL genetic interactions for rational cancer therapy has been supported by the application of PARP inhibitors for maintenance therapy of breast and ovarian cancers with BRCA1 or BRCA2 defects. To exploit additional SL interactions for cancer therapy, this proposal aims to leverage the wealth of knowledge on GIS genes and their SL partners developed in yeast to guide the development of therapeutics that target human GIS gene defects that cause GCRs in cancer. Specifically, the proposed studies will focus on the human Flap Endonuclease 1 (FEN1), the homolog of yeast RAD27, which has the highest number of SL-interactions with GIS genes of a variety of functions. FEN1 processes Okazaki fragments during lagging strand DNA synthesis and acts in long-patch base excision repair but is itself non- essential. To develop this nuclease as a target for treating cancers with defects in BRCA1, BRCA2 and other FEN1-SL partner GIS genes, we propose to carry out the following lines of research: AIM 1) To expand ongoing CRISPR-dropout screens and validation studies in cell lines and mice to (a) identify human genes in which defects cause sensitivity to our proprietary FEN1-inhibitors of highly potency and specificity and (b) define FEN1 SL-partner genes as well as cancer omics signatures that can be targeted with FEN1 inhibitors to induce SL; AIM 2) To combine informatics and cell-based validation approaches for a deep-dive into cancer omics and gene essentiality data to identify the spectrum and signatures of cancers amenable to therapeutic targeting with FEN1 inhibitors; AIM 3) To apply an array of genetics-based approaches to investigate mechanisms for acquired resistance to FEN1 inhibitors and to compare resistance to FEN1 versus PARP inhibitors; and, AIM 4) To determine the effects of FEN1 inhibition on DNA replication, fork stability, and chromosome integrity in BRCA1 and BRCA2 mutant cells to test the hypothesis that FEN1 inhibitors induce irreparable damage to replication forks in HRR-deficient cancer cells to cause lethality. These mechanistic studies will be extended to other validated FEN1-SL partner genes. These projects will greatly accelerate the development of FEN1 inhibitors to target cancer genome instability and will establish an experimental platform for evaluation and development of other potential therapeutic targets to be identified by the proposed research.

项目摘要 染色体重排（GCR）是一种基因组不稳定性（GCRS），经常在遗传和 零星的癌症是恶性进展的重要驱动力。例如，遗传性乳房和 由BRCA1和BRCA2种系突变引起的卵巢癌患有同源重组 修复（HRR）缺陷，增加了模型系统中的GCR。我们以前的研究已经建立了 酵母中基因组不稳定性抑制剂（GIS）基因的综合网络，并在计算机中证明 这些酵母基因的人类同源物在许多癌症上在遗传和/或表观遗传上改变了 类型。从酵母遗传研究中，我们还确定了和排序的合成致命（SL）伴侣 非必需的GIS基因。将SL遗传相互作用用于理性癌症治疗的可行性已有 通过将PARP抑制剂应用于乳腺癌和卵巢癌的维持治疗来支持 与BRCA1或BRCA2缺陷。为了利用其他SL相互作用进行癌症治疗，该建议旨在 利用有关GIS基因及其SL伴侣在酵母中发展的知识的丰富知识来指导 靶向人类GIS基因缺陷的治疗剂的发展会导致癌症GCR。具体来说， 拟议的研究将重点介绍人皮瓣核酸内切酶1（Fen1），酵母Rad27的同源物 与各种功能的GIS基因的SL相互作用数量最多。 Fen1处理冈田 滞后DNA合成过程中的碎片并在长距离碱基切除修复中作用，但本身不是 基本的。将这种核酸酶开发为治疗BRCA1，BRCA2和其他缺陷的癌症的靶标 Fen1-SL合作伙伴GIS基因，我们建议进行以下研究行：目标1） 在细胞系和小鼠中正在进行的CRISPR-DOPOUT屏幕和验证研究（a）在（a）中识别人类基因 缺陷会引起对高效力和特异性的专有Fen1抑制剂的敏感性，并且（b） 定义FEN1 SL-PARTNER基因以及可以针对FEN1抑制剂的癌症幻象特征 诱导SL；目标2）结合信息学和基于细胞的验证方法，以深入研究癌症 OMICS和基因的本质数据，以识别癌症的频谱和签名 用Fen1抑制剂靶向；目标3）应用一系列基于遗传学的方法来调查 获得对Fen1抑制剂的获得性的机制，并将抗性与Fen1与PARP进行比较 抑制剂；并且，目标4）确定FEN1抑制对DNA复制，叉稳定性和 BRCA1和BRCA2突变细胞中的染色体完整性，以检验Fen1抑制剂诱导的假设 HRR缺陷型癌细胞中对复制叉的无法弥补的损害会引起致死性。这些机械 研究将扩展到其他经过验证的FEN1-SL伴侣基因。这些项目将大大加速 开发Fen1抑制剂以靶向癌症基因组不稳定性，并将建立一个实验平台 为了评估和开发其他潜在的治疗靶标，拟议的研究将确定。