Forward Genomics of Damage Control: An Undiscovered Class of Cancer Genes

这个项目的中心假设是，存在一个大的，高度保守的类， 调节所有活细胞中自发DNA损伤水平的基因/蛋白质， 基因组不稳定性的近端、上游效应子/调节子。这些建议是为了 包括许多高度保守的必需基因，在人类中，这些基因被认为构成了 不同于两个主要公认类别（上游）的新癌症基因类别： 基因组看守和看门基因。然而，这些损伤控制基因/蛋白质 由于两个局限性，一直未被发现和认识。第一，没有技术 存在直接测定自发/内源性DNA损伤，特别是DNA断裂， 活细胞因此，影响内源性DNA损伤水平的因素大多没有 被分析过，没有考虑过。第二，许多控制损伤的基因可能是 对生物体生存力至关重要，以及目前在模式生物中的正向遗传方法， 这些基因可能已经发现了其中的一些基因，但对必需基因有偏见。 我们预计损伤控制基因至少包括以下几个方面：（1）正常代谢 途径（碳代谢等）会产生有毒副产品， 导致碱基/核苷酸损伤的DNA;（2）抑制这些副产物的蛋白质/分子; (3)DNA复制组件。(DNA断裂通常是由复制造成的。所有 这些被认为是高度保守的，因为它们是生命的基础， 被认为是必需基因。 本项目的目标是：（1）开发一种新的方法论范式， 基因组学将允许快速鉴定感兴趣的基因，包括必需基因， （2）利用这种范式，在简单的细胞中找到损伤控制基因， 模式生物E.大肠杆菌，确定其在人类中的对应物，然后确定并验证 人类的候选癌症基因。这些结果可能会成为理解 被预测为第三种非常大的、高度保守的和潜在的重要的促癌基因。 突变

The central hypothesis of this project is that there exists a large, highly-conserved class of genes/proteins that regulate levels of spontaneous DNA damage in all living cells, and so are the proximal, upstream effectors/modulators of genome instability. These are proposed to include many highly conserved essential genes that, in humans, are expected to constitute a ¿new¿ class of cancer genes distinct from (upstream of) the two main recognized classes: genomic-caretaker and gatekeeper genes. However these ¿damage-control¿ genes/proteins have remained undiscovered and unrecognized because of two limitations. First, no technology existed to assay spontaneous/endogenous DNA damage, particularly DNA breakage, directly in living cells. Thus, factors that affect the levels of endogenous DNA damage have mostly not been assayed, and not considered. Second, many of the damage-control genes are likely to be essential for organism viability, and current forward-genetic approaches in model organisms, which might otherwise have found some of these genes, are biased against essential genes. We expect the damage-control genes to encompass at least the following: (1) normal metabolic pathways (carbon metabolism, etc.) that unavoidably produce toxic by-products that react with DNA causing base/nucleotide damage; (2) proteins/molecules that scavenge these by-products; (3) DNA replication components. (DNA breaks often result from replication into damage.) All of these are expected to be very highly conserved because they are so basic to life, and most are expected to be essential genes. The goals of this project are--(1) to develop a new methodological paradigm of forward genomics that will allow rapid identification of genes, including essential genes, of interest to any problem in biology; (2) using this paradigm, to find the damage-control genes in the simple model organism E. coli, identify their counterparts in human, then identify and validate the candidate cancer genes in human. The results may form the basis of understanding what is predicted to be a third, very large, highly-conserved and potentially important class of cancerpromoting mutations.