应用RNA-only delivery基因回路靶向治疗CMS2型结肠癌的研究

Lacking cancer-targeting therapy to precisely identify and kill malignant cells has been a great challenge in colon cancer therapy. In the era of molecular classification of tumors, colon cancer has been grouped into four Consensus Molecular Subtypes (CMS). Accounting for 37% of all types, the CMS2 group (canonical type) shows distinguishing features: WNT and MYC signaling activation. RNA-only delivery gene circuits possess superior safety, which could distinguish special types of malignant cells from others by sensing unit and eliminate them without harming other cells. In the previous study, we constructed RNA-only delivery mammalian synthetic circuits, forming ten kinds of two input logic gates that could process logic calculation of two inputs, TEVp and PPVp activity. Based on the previous work, we designed this study to construct an RNA-only delivery gene circuit for specifically targeting and eliminating CMS2 type colon cancer cells. First, we need to construct the sensing unit to detect WNT and MYC signal activation and transform them to TEVp or PPVp activity which could be processed by the logic calculating unit previously built. Then the sensing unit will be connected with the logic processing unit and regulated therapeutic functioning unit to form a complete gene circuit specifically targeting the CMS2 type colon cancer cell. The effectivity and safety of the designed gene circuit will be evaluated both in vitro and in vivo. This research aims at developing a new RNA-only delivery gene circuit to precisely targeting the CMS2 type colon cancer cell, providing a potential therapeutic strategy.

缺乏精准靶向治疗手段是结肠癌治疗中面临的巨大挑战。CMS2型结肠癌以WNT及MYC信号通路异常活化为特征。应用合成生物学构建的RNA-only delivery基因回路有很好的安全性，可通过感应元件区分特定类型的癌细胞与正常细胞，在识别并有效杀伤癌细胞的同时豁免正常细胞。前期研究中，我们已构建了通用型RNA-only delivery基因回路并形成10种双输入逻辑门，可满足以TEVp和PPVp活性作为输入的逻辑判断需求。在此基础上，本项目拟：(1) 构建感应模块以探测MYC及WNT信号通路活化水平；(2) 将上述感应模块与逻辑处理模块及应答模块组合成基因回路，以靶向杀伤CMS2型结肠癌细胞；(3) 在细胞及动物实验中对基因回路的有效性及安全性进行评价。本研究旨在探索RNA-only delivery基因回路在CMS2型结肠癌治疗中的应用，以期为CMS2型结肠癌提供一种精准靶向治疗手段。

缺乏精准靶向治疗手段是结肠癌治疗中面临的巨大挑战。应用合成生物学构建的RNA-only delivery基因回路有很好的安全性，可通过感应元件区分特定类型的癌细胞与正常细胞，在识别并有效杀伤癌细胞的同时豁免正常细胞。在肿瘤分子分类领域，根据基因表达数据及复杂的网络分析，结肠癌被分为4组共识分子亚型。作为经典型，CMS2型结肠癌占37%，居第一位，以WNT及MYC信号通路异常活化为特征。本研究构建了一个RNA-only delivery杀伤回路以特异性杀伤CMS2型结肠癌细胞。工程化改造后的L7Ae蛋白用于整合感知和逻辑判断功能，因为其不仅可探知β-catenin蛋白的稳定性及细胞浆内的Myc/Myc-nick丰度，还可进行逻辑判断。该基因回路在杀伤HCT-116细胞的同时豁免了其他类型的细胞，表现出了很好的特异性，为精准靶向治疗结肠癌提供了一种新的思路及方法。