ATM/CHK1介导有丝分裂期DNA复制影响肿瘤细胞命运的机制研究

有丝分裂期DNA复制（mitotic DNA synthesis，MiDAS），作为一种新的基因组稳定性维持策略对复制压力下的肿瘤细胞生存至关重要，但其调控机制及对肿瘤细胞命运的作用研究仍不清楚。我们前期建立了MiDAS在骨肉瘤细胞U2OS中的检测方法，并发现ATM和CHK1在有丝分裂期显著调控MiDAS的发生，而ATR对MiDAS影响不大，提示ATM/CHK1介导的信号通路参与MiDAS的调控。申请人拟1）通过ATM/CHK1与已知MiDAS因子的互作等方法阐述其介导MiDAS的分子机制；2）利用RNA-seq、IPOND技术挖掘MiDAS新因子，建立一条相对完整的MiDAS调控信号通路；3）明确ATM/CHK1介导的MiDAS在肿瘤细胞有丝分裂中的分配规律及对子代细胞命运的影响。找到合适的靶点选择性调控MiDAS将是一种潜在的肿瘤治疗手段，并使肿瘤对临床上诱导复制压力的众多药物更敏感。

Mitotic DNA synthesis (MiDAS), as a novel genomic stability maintenance strategy, is essential for the survival of tumor cells under replication stress. However, its regulatory mechanisms and its effects on the fate of tumor cells remain unclear. We have previously established a detection method for MiDAS in osteosarcoma cells U2OS, and found that ATM and CHK1 significantly regulate the occurrence of MiDAS during mitosis, while ATR has little effect on MiDAS, suggesting that ATM/CHK1-mediated signaling pathway is involved in the regulation of MiDAS. The applicant intends to 1) elaborate the molecular mechanism of ATM/CHK1-mediated MiDAS through the interaction between ATM/CHK1 and known MiDAS factors; 2) use RNA-seq and IPOND techniques to mine new MiDAS factors to establish a relatively complete MiDAS regulatory signaling pathway; 3) clarify the distribution pattern of ATM/CHK1-mediated MiDAS in mitosis and its influence on the fate of tumor progeny cells. Selective regulation of MiDAS by finding suitable targets will be a potential therapeutic tool for tumors and will make tumors more sensitive to a wide range of drugs that induce replication stress in the clinic.