Replication stress in hematopoiesis and lymphomagenesis

摘要 造血系统对引起DNA复制压力的刺激特别敏感， 这可能导致DNA断裂。对这种压力做出适当反应的能力存在缺陷 与血液系统恶性肿瘤、造血细胞缺乏症和 骨髓衰竭。最近的进展包括识别对dna有反应的基因。 复制应激和更好地理解特定的造血所需的基因 血统，但关于这两个过程以及它们如何交叉导致 病理学。此外，DNA复制应激在人类癌症中观察到，是由 癌基因，如Myc，会导致DNA损伤，并导致基因组不稳定，但它 人们对此仍然知之甚少。对Smarcal1和最近的ZRANB3进行了识别和评估 通过生物化学和体外研究定位到复制叉子并对响应至关重要 与DNA复制压力有关。Smarcal1和ZRANB3是分叉重建器和反向复制 叉子可以修复受损的DNA并倒回单链DNA。Smarcal1和 ZRANB3具有相似的功能，但有报道称存在生化差异。然而，这些函数 ZRANB3和Smarcal1，以及它们在以下情况下是冗余的还是互补的 复制应激或在体内具有独特的功能尚未被探索。最近，我们 遗传学证明Smarcal1在介导急性DNA的作用中是必不可少的 复制应激对造血干和祖细胞的影响 T细胞淋巴瘤的发生。我们的初步数据支持ZRANB3的假设 以不同于Smarcal1的方式促进造血和淋巴生成，并且 ZRANB3和Smarcal1共同促进了造血和淋巴瘤的发展。 因此，我们提出了用体内遗传学方法来检验这一假说的三个目的。1) 探讨ZRANB3在Myc诱导的复制应激中的作用及其在急性和慢性应激中的作用 慢性复制应激导致的淋巴瘤的发生。2)确定ZRANB3在 造血和造血干/祖细胞复制应激。3)评估 ZRANB3和Smarcal1在造血和淋巴生成中的联合功能丧失。 创新的概念通过新的鼠标模型和多种方法进行测试，包括 高分辨率全基因组末端测序。这些目标的实现将显著地 进一步了解DNA复制应激蛋白及其在基因组中的作用 稳定性、造血和血液系统恶性肿瘤。

Summary The hematopoietic system is particularly sensitive to stimuli that cause DNA replication stress, which can result in DNA breaks. Defects in the ability to properly respond to this stress are linked to a predisposition to hematologic malignancies, hematopoietic cell deficiencies, and bone marrow failure. Recent advances include the identification of genes that respond to DNA replication stress and a greater understanding of genes necessary for hematopoiesis of specific lineages, but much remains unknown about both processes and how they intersect to cause pathology. Moreover, DNA replication stress is observed in human cancers, is induced by oncogenes such as Myc, causes DNA damage, and contributes to genome instability, but it remains poorly understood. Smarcal1 and more recently, Zranb3 were identified and evaluated biochemically and by in vitro studies to localize to replication forks and be critical for responding to DNA replication stress. Smarcal1 and Zranb3 are fork remodelers and reverse replication forks to allow repair of damaged DNA and rewind single-stranded DNA. Both Smarcal1 and Zranb3 have similar functions, but biochemical differences are reported. However, the functions of Zranb3 and Smarcal1 and whether they are redundant or complementary at times of replication stress or have unique functions in vivo has not been explored. Recently, we genetically demonstrated that Smarcal1 was essential for mediating the effects of acute DNA replication stress on hematopoietic stem and progenitor cells and contributed to the development of T cell lymphoma. Our preliminary data support the hypothesis that Zranb3 contributes to hematopoiesis and lymphomagenesis in ways distinct from Smarcal1, and that Zranb3 and Smarcal1 together contribute to hematopoiesis and lymphoma development. Therefore, we propose three Aims with in vivo genetic approaches to test this hypothesis. 1) Investigate the role of Zranb3 in Myc-induced replication stress and its contribution to acute and chronic replication stress-induced lymphoma development. 2) Determine the role of Zranb3 in hematopoiesis and hematopoietic stem and progenitor cell replication stress. 3) Evaluate the combined loss of function of Zranb3 and Smarcal1 in hematopoiesis and lymphomagenesis. Innovative concepts are tested with a new mouse model and multiple approaches, including high-resolution genome wide end-sequencing. Completion of these Aims will significantly advance understanding into DNA replication stress proteins and their contribution to genome stability, hematopoiesis, and hematological malignancies.