p53突变型肿瘤特异性干预基因线路的设计、构建与功能测试

以p53为靶点的治疗策略是肿瘤研究的热点之一。本项目组将Cre/LoxP系统与p53适体核酶相连接，构建了一个p53突变型肿瘤细胞特异性识别与干预的基因线路。初步结果显示，该基因线路可显著降低p53突变型肿瘤细胞的增殖能力，而对p53野生型细胞无明显影响。本项目将采用细胞增殖实验、细胞划痕实验和流式细胞分析等技术，进一步确定该基因线路对肿瘤细胞生长、迁移和凋亡的影响；以结直肠癌患者来源的肿瘤组织异种移植(PDX)模型为实验对象，采用瘤内注射方式，将腺病毒包装的p53突变型肿瘤特异性干预基因线路导入肿瘤组织，探讨该基因线路对p53基因突变型PDX肿瘤模型的治疗作用。该项目的实施，对于恶性肿瘤的精准治疗具有重要的学术价值，也将具有广泛的应用前景。

Looking for new therapeutic strategies on p53 target has been one of the hot spots in cancer research. In the previous study, we synthetized a new gene circuit by assembling a vector of Cre-p53 aptazyme driven by human telomerase reverse transcriptase (hTERT) promoter and a vector of LoxP-EGFP-LoxP-Diphtheria toxin driven by human elongation factor 1A (hEF1a) promoter, which was named “Cre/LoxP-p53 aptazyme gene circuit”, and demonstrated that this gene circuit specifically inhibited the growth of the cancer cells with p53 gene mutation in vitro and in vivo, but had no significantly effects on the growth of the cells with wide-type p53. This project will further study the effects of the Cre/LoxP-p53 aptazyme gene circuit on the growth, migration and apoptosis of the cancer cells with wide-type or mutated p53 gene by the assays of cell counting kit-8, cell migration and flow cytometry. We also plan to set the nude mice model of patient-derived xenograft (PDX) with cancer tissues from the patients with colorectal cancer. With this model, we will investigate the therapeutic effects of the Cre/LoxP-p53 aptazyme gene circuit-AAV on the growth and metastasis of colorectal cancer with or without p53 mutation. This project is valuable for the cancer precise medicine, and also have a great application prospect in the future.