靶向PCID2阻滞DCTPP1介导的肝癌细胞DNA合成的作用机制及查尔酮类化合物优化

细胞异常增殖是肿瘤发生的主要特征。我们前期药物干预后肝癌细胞转录组学数据发现了新的增殖及周期调控因子PCID2，其沉默后的蛋白组学数据发现DNA合成关键蛋白DCTPP1显著下调，且二者发生蛋白互作，发现其参与肿瘤细胞周期调控。天然产物库分子对接发现与该蛋白结合较好的化合物具有共同骨架-查尔酮结构，其中查尔酮衍生物DMCC显著下调PCID2表达水平，在肝癌增殖抑制中体现了良好的活性。分子动力学模拟发现DMCC主要结合于PCID2的结构稳定区（PCID2-DSS1）。据此假设：DMCC通过靶向PCID2抑制DCTPP1阻滞肝癌进程。本课题拟采用蛋白互作及结合位点分析，阐明PCID2通过DCTPP1调节肝癌细胞增殖的机制；利用冷冻电镜分析DMCC抑制PCID2活性的关键基团及其多靶点结合特性，并以此为依据优化DMCC分子结构，以期合成出细胞周期特异性靶点高效抑制剂，为肿瘤靶向药物研发奠定基础。

Abnormal cell proliferation is a major feature of tumorigenesis. Our transcriptome data after treated hepatocellular carcinoma cells with drug intervention revealed a novel regulator of tumor cell proliferation and cycle: PCID2. The proteomic data after silenced PCID2 showed that DCTPP, a critical protein of DNA synthesis, was significantly down-regulated. BiFC showed that PCID2 and DCTPP1 interacted with each other. The results suggest that PCID2 involved in regulating tumor cell cycle. The molecular docking analysis from the natural product bank found compounds binding well to PCID2 had a common skeleton-chalcone structure, among which the chalcone derivative DMCC significantly down-regulated PCID2 expression. DMCC presented a good inhibitory activity against HCC cell proliferation. Molecular dynamics simulation showed that DMCC was mainly bound to the stabilized region of PCID2 (pcid2-dss1). Based on the above, we hypothesized DMCC inhibits DCTPP1 mediated DNA synthesis by targeting PCID2 to block HCC progression. In this study, protein interaction and binding site analysis were used to elucidate the mechanism of PCID2 regulating cell proliferation by affecting DCTPP1. The key radicals of DMCC inhibiting PCID2 activity and its targeted binding pattern will be analyzed by Frozen electron microscopy(Cryo-EM). Based on this, the molecular structure of DMCC will be optimized, so as to synthesize more efficient inhibitors with cell cycle specific targets, and dedicate to the research and development of targeted drugs against HCC.