Molecular Mechanism of Mammalian DNA Excision Repair and the Circadian Clock

哺乳动物DNA切除修复和生物钟的分子机制

基本信息

批准号：
10799054
负责人：
AZIZ SANCAR
金额：
$ 2.74万
依托单位：
UNIV OF NORTH CAROLINA CHAPEL HILL
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-04-01 至 2026-08-31
项目状态：
未结题

项目摘要

ABSTRACT We work on molecular mechanisms of nucleotide excision repair and the mammalian circadian clock. We have recently made both the technological and mechanistic progress in both of these areas and obtained direct evidence of inter-connectedness of these two fields. Our findings in both fields are directly applicable to human health. We will apply these new advances for the following objectives: (1) We have developed higher resolution versions of our original XR-seq method for genome-wide single-nucleotide resolution mapping of repair of all DNA damage that is processed by nucleotide excision repair, including damage induced by carcinogens and chemotherapeutic drugs. In addition, we developed Damage-seq methods for similarly genome-wide single nucleotide resolution mapping of DNA damage. We have used the combination of the two methods to discover repair hotspots and coldspots that do not overlap damage hotspots or coldspots and have gained novel information on genome 3D and repair. We will continue characterizing these features to link repair to epigenomic markers, 3D genome organization, chromatin states, and replication timing. (2) We will define the molecular mechanism of the mammalian circadian clock. Recently, we demonstrated that Cryptochrome (CRY), and not Period (PER), is the repressor in the mammalian transcription-translation feedback loop (TTFL), and that PER acts either as a repressor or an activator, depending on the particular gene, in a CRY- dependent manner. We will carry out experiments to reconstitute this model in an in vitro system with purified proteins. (3) Circadian clock, cancer, and chemotherapy. For the first time, we have been able to map both damage formation by cisplatin and its repair in mouse tissues including liver, kidney, and lung, genome-wide and at single-nucleotide resolution. We made the exciting discovery that for most genes the transcribed strand (TS) and non-transcribed strand (NTS) are repaired at different times of the day. We plan to take advantage of this finding to develop more efficient chronotherapy regimens, first for colorectal cancers, and in the future for other types of cancers that are treated with cisplatin and oxaliplatin. The proposed research is innovative because it is based on our discoveries in the fields of DNA repair and circadian clock, and it is significant because of its relevance for cancer prevention and treatment.

抽象的我们致力于核苷酸切除修复和哺乳动物的分子机制生物钟。我们最近在技术和机械方面都取得了进步在这两个领域，并获得了这两个领域相互关联的直接证据字段。我们在这两个领域的研究结果直接适用于人类健康。我们将申请这些新进展旨在实现以下目标： (1) 我们开发了原始 XR-seq 方法的更高分辨率版本所有 DNA 损伤修复的全基因组单核苷酸分辨率图谱通过核苷酸切除修复进行处理，包括致癌物和化疗药物。此外，我们还开发了 Damage-seq 方法用于类似的 DNA 损伤的全基因组单核苷酸分辨率图谱。我们已经使用了结合两种方法来发现不修复的热点和冷点重叠损伤热点或冷点并获得了基因组 3D 的新信息和修复。我们将继续表征这些特征，将修复与表观基因组联系起来标记、3D 基因组组织、染色质状态和复制时间。 (2)我们将定义哺乳动物生物钟的分子机制。最近，我们证明了隐色色素 (CRY)，而不是周期 (PER)，才是哺乳动物转录翻译反馈环 (TTFL) 中的阻遏蛋白，以及 PER 根据特定基因，在 CRY- 依赖方式。我们将进行实验以在体外重建该模型系统与纯化的蛋白质。 (3) 生物钟、癌症和化疗。我们第一次能够绘制顺铂损伤形成及其在小鼠组织（包括肝脏）中的修复图谱，肾脏和肺，全基因组和单核苷酸分辨率。我们创造了令人兴奋的发现对于大多数基因来说，转录链（TS）和非转录链 (NTS) 在一天中的不同时间进行修复。我们计划利用这一发现开发更有效的时间疗法方案，首先针对结直肠癌，然后在顺铂和奥沙利铂治疗其他类型癌症的未来。这拟议的研究具有创新性，因为它基于我们在以下领域的发现 DNA 修复和生物钟，因其与癌症的相关性而具有重要意义预防和治疗。