Modelling ADP-ribosyltransferases as therapeutic targets in cancer therapy

将 ADP-核糖基转移酶建模为癌症治疗中的治疗靶点

• 批准号: MR/L000164/1
• 负责人: Nicholas Lakin
• 金额: $ 51.39万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2014
• 资助国家: 英国
• 起止时间: 2014 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FL000164%2F1
• 关键词: Modelling; ADP; ribosyltransferases; therapeutic; targets

The genome contains a blueprint to produce all the machinery required for cells to function. As such, it is important to maintain the integrity of its constituent DNA. Unfortunately cells are exposed to agents that damage DNA. For example, ionizing radiation (IR) coverts water into reactive oxygen species (ROS) that introduces breaks into the DNA, or alters the bases that encode for proteins. Therefore, cells have evolved multiple mechanisms to repair different types of DNA damage, and these pathways are increasingly well defined. However, a remaining challenge is to understand how these pathways integrate to allow cells to survive IR and other mutagenic agents when one repair pathways fails. Understanding this redundancy has important implications for health and wellbeing. For example, DNA repair pathways are often inactivated in cancer cells and the relative sensitivity of these cells to IR and other DNA damaging agents is exploited in radio/chemotherapy. Defining compensatory pathways that allow cancer cells to tolerate these agents will facilitate the development of drugs that inhibit these pathways and further sensitize cancers to radio/chemotherapy. Importantly, ROS are produced naturally in cells. Therefore, this knowledge will also provide insights into how cancer cells can be sensitized to this endogenous DNA damage, circumventing the requirement for radio/chemotherapy and thus eliminating the inherent toxicity and unwanted side effects of these treatments.An example of such a strategy is inhibition of proteins known as ADP-ribosyltransferases (ARTs) that sense DNA breaks and chemically modify proteins at the DNA damage sites to promote repair. ART inhibitors (ARTi) are currently being developed in the clinic to treat breast and ovarian cancers with defects in the ability to repair DNA breaks by homologous recombination (HR). Importantly, treatment with ARTi is most promising in combination with IR or other mutagens. However, many questions remain regarding how and why ARTi kill HR-defective cancers that, if resolved, will improve the efficacy of these agents. For example, cells contain multiple ARTs that respond to different types of DNA damage and we have identified a significant degree of redundancy between ARTs. Understanding these relationships will facilitate the development of more specific ARTi that refine treatment strategies. Further, whilst ARTi kill certain tumour cells, it is important to establish how they impact on DNA integrity in non-cancer cells, especially in combination with IR. Finally, whilst certain cancers are highly sensitive to ARTi, they rapidly adapt to treatment with these agents. Identifying genes that, when de-regulated, render cancer cells refractory to ARTi treatment will provide potential targets that when inhibited will overcome this resistance.DNA repair pathways function in a similar manner in a wide variety of organisms. Therefore, a powerful approach to address these questions is to exploit the ease of experimentation in relatively simple model organisms and extend the findings to humans. Unfortunately, this approach is hampered by the lack of certain DNA repair proteins in the most commonly used model organisms to study DNA repair. Recently, however, we initiated a study of DNA repair in the microorganism Dictyostelium and have established that it contains a number of DNA repair proteins, including ARTs, absent in other model organisms. Therefore, Dictyostelium will prove an important model to investigate selected DNA repair pathways and redundancy. The overall objectives of this proposal are to exploit the advantages of Dictyostelium and human cells to address the following:i) How do multiple ARTs regulate compensatory repair mechanisms following DNA damage?ii) What is the impact of long term ART inhibition on genome stability in the presence or absence of agents used in radiotherapy?iii) How do HR-defective cells become refractory to ARTi?

基因组包含一个蓝图，可以产生细胞功能所需的所有机制。因此，重要的是保持其组成DNA的完整性。不幸的是，细胞暴露于破坏DNA的试剂中。例如，电离辐射（IR）将水转化为活性氧（ROS），从而将断裂引入DNA，或改变编码蛋白质的碱基。因此，细胞已经进化出多种机制来修复不同类型的DNA损伤，并且这些途径越来越明确。然而，剩下的挑战是了解这些途径如何整合，以允许细胞在一个修复途径失败时存活IR和其他诱变剂。了解这种冗余对健康和福祉具有重要意义。例如，DNA修复途径通常在癌细胞中失活，并且这些细胞对IR和其他DNA损伤剂的相对敏感性在放射/化学疗法中被利用。定义允许癌细胞耐受这些药剂的补偿途径将促进抑制这些途径的药物的开发，并进一步使癌症对放射/化学疗法敏感。重要的是，ROS在细胞中自然产生。因此，这些知识也将提供洞察如何癌细胞可以敏感这种内源性DNA损伤，规避放射/化疗的要求，从而消除这些治疗的固有毒性和不必要的副作用，这样的策略的一个例子是被称为ADP-核糖基转移酶（ART）的蛋白质的抑制，该蛋白质感知DNA断裂并在DNA损伤位点化学修饰蛋白质以促进修复。ART抑制剂（阿尔蒂）目前正在临床上开发，用于治疗具有通过同源重组（HR）修复DNA断裂能力缺陷的乳腺癌和卵巢癌。重要的是，阿尔蒂治疗与IR或其他诱变剂联合使用最有前景。然而，关于阿尔蒂如何以及为什么杀死HR缺陷型癌症的许多问题仍然存在，如果解决这些问题，将提高这些药物的疗效。例如，细胞含有多种对不同类型的DNA损伤做出反应的ART，并且我们已经确定了ART之间的显著冗余程度。了解这些关系将有助于开发更具体的阿尔蒂，以完善治疗策略。此外，虽然阿尔蒂杀死某些肿瘤细胞，但重要的是确定它们如何影响非癌细胞中的DNA完整性，特别是与IR组合。最后，虽然某些癌症对阿尔蒂高度敏感，但它们迅速适应用这些药剂治疗。鉴定基因，当去调控时，使癌细胞对阿尔蒂治疗难治，将提供潜在的靶点，当抑制时将克服这种抗性。因此，解决这些问题的一个强有力的方法是利用相对简单的模式生物实验的便利性，并将研究结果扩展到人类。不幸的是，这种方法受到了最常用的模式生物中缺乏某些DNA修复蛋白来研究DNA修复的阻碍。然而，最近，我们发起了一项研究的DNA修复的微生物Dictyosteoblasts，并已确定，它包含了一些DNA修复蛋白，包括ART，缺乏在其他模式生物。因此，Dictyosteoblasts将被证明是一个重要的模式，研究选定的DNA修复途径和冗余。本提案的总体目标是利用网骨藻和人类细胞的优势来解决以下问题：i）多种ART如何调节DNA损伤后的补偿修复机制？ii）在存在或不存在用于放射治疗的药剂的情况下，长期ART抑制对基因组稳定性的影响是什么？iii）HR缺陷细胞如何变得对阿尔蒂不敏感？

项目成果

Microbe Profile: Dictyostelium discoideum: model system for development, chemotaxis and biomedical research.

微生物概况：盘基网柄菌：发育、趋化性和生物医学研究的模型系统。

• DOI: 10.1099/mic.0.001040
• 发表时间: 2021
• 期刊: Microbiology (Reading, England)
• 作者: Pears CJ

Dictyostelium as a Model to Assess Site-Specific ADP-Ribosylation Events.

盘基网柄菌作为评估位点特异性 ADP-核糖基化事件的模型。

• DOI: 10.1007/978-1-4939-8588-3_9
• 发表时间: 2018
• 期刊: Methods in molecular biology (Clifton, N.J.)
• 作者: Kolb AL

The role of ADP-ribosylation in regulating DNA interstrand crosslink repair.

• DOI: 10.1242/jcs.193375
• 发表时间: 2016-10-15
• 期刊: Journal of cell science
• 影响因子: 4
• 作者: Gunn AR;Banos-Pinero B;Paschke P;Sanchez-Pulido L;Ariza A;Day J;Emrich M;Leys D;Ponting CP;Ahel I;Lakin ND
• 通讯作者: Lakin ND

Site-specific ADP-ribosylation of histone H2B in response to DNA double strand breaks.

• DOI: 10.1038/srep43750
• 发表时间: 2017-03-02
• 期刊: Scientific reports
• 影响因子: 4.6
• 作者: Rakhimova A;Ura S;Hsu DW;Wang HY;Pears CJ;Lakin ND
• 通讯作者: Lakin ND

PARP1 and PARP2 stabilise replication forks at base excision repair intermediates through Fbh1-dependent Rad51 regulation.

• DOI: 10.1038/s41467-018-03159-2
• 发表时间: 2018-02-21
• 期刊: Nature communications
• 影响因子: 16.6
• 作者: Ronson GE;Piberger AL;Higgs MR;Olsen AL;Stewart GS;McHugh PJ;Petermann E;Lakin ND
• 通讯作者: Lakin ND