Project 2: Targeting DNA replication in BRCA-associated breast cancer

项目 2：针对 BRCA 相关乳腺癌中的 DNA 复制

• 批准号: 10599900
• 负责人: Bing Xia
• 金额: $ 37.12万
• 依托单位: RUTGERS BIOMEDICAL AND HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-01 至 2026-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10599900
• 关键词: Ablation; Address; Aftercare; BRCA deficient; BRCA1 gene; BRCA2 gene; Binding; Breast; Breast Cancer Cell; Breast Cancer Risk Factor; Breast Cancer cell line; Cancer Etiology; Cell Proliferation; Cells; ChIP-seq; Clinical; Clone Cells; DNA; DNA Damage; DNA Double Strand Break; DNA Repair; DNA Replication Factor; DNA biosynthesis; DNA lesion; DNA replication fork; Defect; Development; Disease; Double Strand Break Repair; Doxorubicin; Drug resistance; Engineering; Fiber; Generations; Genes; Genome Stability; Genomic Instability; Germ-Line Mutation; Kinetics; Knockout Mice; MCM10 gene; Malignant Neoplasms; Mammary Neoplasms; Mammary Tumorigenesis; Measures; Modeling; Molecular; Mutation; Ovarian; PALB2 gene; Pancreas; Phenocopy; Phenotype; Platinum; Play; Poly(ADP-ribose) Polymerase Inhibitor; Prostate; Proteins; Public Health; Regulation; Relapse; Research; Resistance; Risk; Role; S phase; SLC19A1 gene; Salts; Speed; Testing; Time; Topoisomerase; Topoisomerase Inhibitors; Topoisomerase-I Inhibitor; Tumor Suppressor Proteins; Type I DNA Topoisomerases; Xenograft procedure; cancer cell; cancer therapy; chemotherapy; combat; comparative efficacy; conditional knockout; efficacy evaluation; gene product; genome sequencing; high risk; histone methyltransferase; homologous recombination; inhibitor; irinotecan; malignant breast neoplasm; mouse model; mutant; radioresistant; rational design; recombinational repair; repaired; replication stress; response; restraint; side effect; targeted treatment; treatment response; triple-negative invasive breast carcinoma; tumor; tumorigenesis; whole genome

PROJECT SUMMARY Germline mutations in BRCA1 and BRCA2 and PALB2 predispose to breast cancer and also increase the risks of ovarian, pancreatic, prostate, and other cancers. The products of the 3 genes constitute a BRCA1-PALB2- BRCA2 axis that plays essential roles in the DNA damage response, particularly in DNA double strand break repair by homologous recombination (HR). In addition, BRCA1 and BRCA2 have also been implicated in the regulation of DNA replication after DNA damage, as their mutant cells are defective in the intra-S phase checkpoint, which slows down DNA synthesis after the damage presumably to allow time for DNA repair and minimize the generation of mutations. However, the mechanisms by which the two proteins regulate DNA synthesis have remained elusive, and the impact of such “unrestrained” DNA synthesis on replication fidelity and genome stability after DNA damage remains unknown. In our preliminary studies, we found that BRCA2 interacts with an essential DNA replication factor, MCM10, and that either loss of BRCA2 or disruption of the BRCA2- MCM10 interaction results in unrestrained replication fork speed, reduced fork stalling, and reduced origin firing after DNA damage and replication stress. Moreover, we also found that loss of BRCA1 leads to reduced replication fork speed both before and after DNA damage. In this proposal, we will determine how BRCA2 and BRCA1 regulate DNA replication kinetics, the impact of unrestrained DNA synthesis on replication fidelity and therapy response, and the potential of replication stress inducers as a targeted therapy for BRCA and PALB2 mutant cancers. In Aim 1, we will define the mechanisms of BRCA2 and BRCA1 in the regulation of replication fork speed, fork stalling and origin firing after replication stress induced by topoisomerase inhibitors. In Aim 2, we will engineer triple negative breast cancer (TNBC) cell lines to assess the impact of replication kinetics dysregulation on replication fidelity, cancer cell response to topoisomerase inhibitors and potential relapse after treatment. In Aim 3, we will use conditional knockout and syngeneic mouse models to determine the efficacy of replication stress inducers on Brca1, Brca2 and Palb2 null mammary tumors.

项目概要 BRCA1、BRCA2 和 PALB2 的种系突变易患乳腺癌并增加风险 卵巢癌、胰腺癌、前列腺癌和其他癌症。 3个基因的产物构成BRCA1-PALB2- BRCA2 轴在 DNA 损伤反应中发挥重要作用，特别是在 DNA 双链断裂中 通过同源重组（HR）进行修复。此外，BRCA1和BRCA2也与该疾病有关。 DNA 损伤后 DNA 复制的调节，因为它们的突变细胞在 S 内期有缺陷 检查点，它会在损伤后减慢 DNA 合成，可能是为了给 DNA 修复留出时间 最大限度地减少突变的产生。然而，这两种蛋白质调节 DNA 的机制 合成仍然难以捉摸，这种“不受限制”的 DNA 合成对复制保真度和 DNA 损伤后基因组的稳定性仍未知。在我们的初步研究中，我们发现 BRCA2 相互作用 具有重要的 DNA 复制因子 MCM10，并且 BRCA2 丢失或 BRCA2- 被破坏 MCM10 相互作用导致复制叉速度不受限制、减少叉停顿并减少起源激发 DNA 损伤和复制应激后。此外，我们还发现 BRCA1 的缺失会导致 DNA 损伤之前和之后的复制叉速度。在本提案中，我们将确定 BRCA2 和 BRCA1 调节 DNA 复制动力学、不受限制的 DNA 合成对复制保真度的影响以及 治疗反应以及复制应激诱导剂作为 BRCA 和 PALB2 靶向治疗的潜力 突变癌症。在目标1中，我们将定义BRCA2和BRCA1在复制调节中的机制 拓扑异构酶抑制剂诱导复制应激后的分叉速度、分叉失速和原点激发。在目标 2 中， 我们将设计三阴性乳腺癌 (TNBC) 细胞系来评估复制动力学的影响 复制保真度失调、癌细胞对拓扑异构酶抑制剂的反应以及术后潜在的复发 治疗。在目标 3 中，我们将使用条件敲除和同基因小鼠模型来确定 Brca1、Brca2 和 Palb2 缺失乳腺肿瘤的复制应激诱导剂。