Identifying Novel Mechanisms and Regulators of Genome Stability

描述(申请人提供)：细胞维持其基因组稳定的能力是生存的关键，真核细胞不断受到外源和内源DNA损伤的挑战。细胞在复制过程中特别容易受到DNA损伤，当复制阻止损伤可能导致复制叉子坍塌和形成双链断裂。结果，细胞微调了修复复制期间DNA损伤的过程，并稳定并重新启动了在DNA复制期间停滞不前的叉子。重要的是，这些过程中的缺陷与越来越多的人类疾病有关，其中包括一些与先天性和发育缺陷以及癌症易感性相关的综合征。这里提出的研究的总体目标是识别和表征与维持基因组完整性和复制分叉稳定性有关的新的途径和蛋白质。我们最近在人类细胞中进行了一项无偏见的全基因组siRNA筛选，以确定参与这些过程的候选基因。在我们的筛查中，有许多以前未知的基因与基因组稳定途径有关。在这里，我们提出了一系列额外的测试，以确定新的影响复制叉稳定性的候选因素。我们采取的不偏不倚的方法有可能揭示基因组稳定性和其他细胞过程之间意想不到的联系，并定义细胞维持基因组稳定性的新机制。因此，我们预计这些实验将开辟新的研究途径。公共卫生相关性：DNA损伤反应通路的缺陷与越来越多的人类疾病有关，其中包括与癌症易感性以及先天性和发育缺陷有关的一些综合征。因此，我们可能与复制分叉稳定性有关的蛋白质和过程可能与其中一些疾病有关，而了解与这些综合征相关的信号通路所获得的知识可能为它们的诊断、治疗和病因学提供关键的见解。

DESCRIPTION (provided by applicant): The ability of the cell to maintain the stability of its genome is critical for survival, and eukaryotic cells are constantly challenged by both exogenous and endogenous sources of DNA damage. Cells are particularly susceptible to DNA damage during replication, when replication-blocking lesions can lead to collapse of a replication fork and formation of a double-strand break. As a result, cells have finely tuned processes to repair DNA damage during replication and to stabilize and restart forks that have stalled during DNA replication. Importantly, defects in these processes have been linked to a growing number of human diseases, among which are a number of syndromes associated with congenital and developmental defects as well as a predisposition to cancer. The overall objective of the studies proposed here is to identify and characterize new pathways and proteins involved in maintaining genomic integrity and replication fork stability. We recently conducted an unbiased genome-wide siRNA screen in human cells to identify candidate genes involved in these processes. Amongst our screening hits are many genes with no previously known connections to genome stability pathways. Here, we propose a series of additional assays to identify novel effectors of replication fork stability among our candidates. The unbiased approach we have taken has the potential to reveal unexpected connections between genome stability and other cellular processes, and to define new mechanisms by which cells maintain genome stability. Thus, we anticipate that these experiments will open novel avenues of investigation. PUBLIC HEALTH RELEVANCE: Defects in DNA damage response pathways have been linked to a growing number of human diseases, among which are a number of syndromes associated with a predisposition to cancer as well as congenital and developmental defects. Thus, the proteins and processes that we may link to replication fork stability could be responsible for some of these disease, and the knowledge gained from understanding the signaling pathways linked to these syndromes could provide critical insights relevant to their diagnosis, treatment and etiology.