The catalytic and non-catalytic functions of PARP1 in cancer biology

PARP1 在癌症生物学中的催化和非催化功能

基本信息

批准号：
9886208
负责人：
Shan Zha
金额：
$ 36.6万
依托单位：
COLUMBIA UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-04-01 至 2023-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9886208
关键词：
ADP ribosylation Adenosine Diphosphate Ribose Affect Alleles Animal Model BRCA1 gene Binding Biological Biology Breast Cancer Biology Catalysis Catalytic Domain Cells Cellular biology Chromatin Chromosomal Instability Chromosomal Stability Clinical Complex DNA DNA Adducts DNA Binding DNA Damage DNA Ligases DNA Repair DNA biosynthesis DNA lesion DNA strand break Development Dominant-Negative Mutation Embryo Epigenetic Process Event Family member Female Fingers Future Gender Genetic Genetic Transcription Genome Stability Goals Histones Hypersensitivity Knock-in Link Malignant Neoplasms Molecular Biology Mus Mutation Ovarian Pathway interactions Physiological Poly Adenosine Diphosphate Ribose Poly(ADP-ribose) Polymerases Proteins Radiation Radiation Tolerance Radiation-Sensitizing Agents Reactive Oxygen Species Resistance Role Sex Bias Single Strand Break Repair Site Structure Testing Therapeutic Effect Therapeutic Intervention Transferase Woman X Chromosome X Inactivation XRCC1 gene base cancer cell cancer radiation therapy cancer therapy cancer type cytotoxicity demethylation desensitization epigenetic regulation experimental study genetic approach genotoxicity in vivo inhibitor/antagonist male mouse genetics mouse model negative affect novel novel anticancer drug prevent protein expression recruit repaired response structural biology tumorigenesis

项目摘要

Cancer radiation therapy generates DNA lesions and reactive oxygen species, which activate Poly ADP-ribose polymerase 1 (PARP1) and its related family member PARP2. Activated PARP1/2 transfers ADP- Ribose to themselves and histones. The resulted poly (ADP-ribose) (PAR) chains further recruit others repair proteins (e.g. XRCC1-Lig3 complex). Specific inhibitors for both PARP1 and 2 (refer to as PARPi) preferentially target BRCA1/2 deficient cancer cells and synergize with other genotoxic cancer therapies, including radiation. While these effects were originally attributed to the lack of PAR dependent recruitment of XRCC1, deletion of XRCC1 does not have the same cytotoxicity as PARPi. More recently PARPi was found to trap PARP1 at DNA breaks, converting transient PARP1 foci (<10min) to durable ones (>30 min). If not removed, the PARP1-DNA adduct can prevent DNA repair and stall replication. Accordingly PARP1 deletion “desensitizes” cancer cells to PARPi, revealing a structural function of PARP1 in cancer therapy. In preliminary studies, we found unexpectedly the release of PARP1 from DNA is regulated by PARP2 and mono-ADP-ribosylation (MARylation), but not PARylation. To understand this structural function of PARP1 in vivo, we generated mouse models expressing constitutive (Parp1A) or inducible (Parp1AN) PARylation defective PARP1 (E988A) and a conditional PARP1 mouse model (Parp1C). In contrast to the normal development and gender distribution of Parp1-/- mice, Parp1+/A mice display female specific embryonic lethality. And male Parp1+/A cells display severe hypersensitivity to DNA damage agents beyond what is found in Parp1-/- ctrl. Given the application of PARP inhibitor in cancer types almost exclusively affecting women (breast and ovarian), this gender bias is intriguing and might be caused by the breaks independent binding of PARP1 on the chromatin and an role of PARP1 protein in X-inactivation and other epigenetic regulation. Female Parp1+/-Parp2-/- (but not Parp1-/-Parp2+/-) mice also display female specific lethality accompanied by X-chromosome specific instability. Based on these findings, we hypothesize that PARP1 has structural function in chromatin biology and DNA repair that are critical for cancer therapy. To test this, we will use mouse genetics, structural biology and cell biology approaches to 1) determine the mechanism that regulates PARP1 dynamics at DNA damage sites, reveal the biological consequence of PARP1 trapping and 2) characterize PARP1 E988A mouse models to determine the impact of catalytic inactive PARP1 on DNA repair, X-inactivation, oncogenesis in vivo. The completion of this study will elucidate the previously un-recognized structural function of PARP1, reveal functional interactions between PARP1 and PARP2 and the gender specific role of PARP1 in female. In the near future, the mechanism and the novel animal models generated in the course of our study will also facilitate the development and use of PARP inhibitors for cancer therapy.

癌症放射治疗会产生 DNA 损伤和活性氧，从而激活 Poly ADP-核糖聚合酶 1 (PARP1) 及其相关家族成员 PARP2 传输 ADP-。产生的聚（ADP-核糖）（PAR）链进一步招募其他核糖进行修复。优先使用 PARP1 和 2（称为 PARPi）的特异性抑制剂。靶向 BRCA1/2 缺陷癌细胞，并与其他基因毒性癌症疗法（包括放射疗法）产生协同作用。虽然这些影响最初归因于 XRCC1 缺乏 PAR 依赖性募集，但缺失 XRCC1 不具有与 PARPi 相同的细胞毒性，最近发现 PARPi 可在 DNA 上捕获 PARP1。断裂，将短暂的 PARP1 焦点（<10 分钟）转换为持久的 PARP1 焦点（>30 分钟）。加合物可以阻止 DNA 修复并阻止复制，因此 PARP1 缺失会使癌细胞“脱敏”。 PARPi，揭示了 PARP1 在癌症治疗中的结构功能在初步研究中，我们发现。出乎意料的是，PARP1 从 DNA 中的释放受到 PARP2 和单 ADP 核糖基化的调节 (MARylation)，但不是 PARylation 为了了解 PARP1 在体内的这种结构功能，我们生成了。表达组成型 (Parp1A) 或诱导型 (Parp1AN) PARylation 缺陷型 PARP1 (E988A) 的小鼠模型和条件性 PARP1 小鼠模型（Parp1C）与正常发育和性别相反。 Parp1-/- 小鼠的分布，Parp1+/A 小鼠表现出雌性特异性胚胎致死性，而雄性 Parp1+/A 细胞。对 Parp1-/- ctrl 中发现的 DNA 损伤剂表现出严重过敏。 PARP 抑制剂在几乎只影响女性（乳腺癌和卵巢癌）的癌症类型中的应用，这性别偏见很有趣，可能是由 PARP1 在染色质上的独立结合断裂引起的以及 PARP1 蛋白在 X 失活和其他表观遗传调控中的作用。雌性 Parp1+/-Parp2-/-（但不是）。 Parp1-/-Parp2+/-) 小鼠还表现出雌性特异性致死性，并伴有 X 染色体特异性不稳定性。基于这些发现，我们追寻 PARP1 在染色质生物学和 DNA 中具有结构功能为了测试这一点，我们将使用小鼠遗传学、结构生物学和细胞。生物学方法 1) 确定在 DNA 损伤位点调节 PARP1 动态的机制，揭示 PARP1 捕获的生物学后果，2) 表征 PARP1 E988A 小鼠模型确定催化失活的 PARP1 对 DNA 修复、X 失活、体内肿瘤发生的影响。这项研究的完成将阐明以前未被认识的 PARP1 结构功能，揭示 PARP1 和 PARP2 之间的功能相互作用以及 PARP1 在女性中的性别特异性作用。在不久的将来，我们研究过程中产生的机制和新颖的动物模型也将促进用于癌症治疗的 PARP 抑制剂的开发和使用。