联合CLIP标签蛋白和iCasp9自杀基因构建多步骤序贯控制型FGFR4-CAR T细胞治疗横纹肌肉瘤的研究

横纹肌肉瘤是源于间叶细胞的恶性肿瘤，其晚期患者治疗效果仍不理想，亟需有效的治疗手段。CAR T细胞虽在血液肿瘤方向取得了可喜的临床疗效，但是在实体肿瘤领域仍然面临如靶点缺乏、产能不足、浸润无效以及毒副反应等问题。本项目在前期预实验中证实了FGFR4作为横纹肌肉瘤CAR T细胞治疗靶点的有效性和安全性，而且联合BC-CLIP标签蛋白和iCasp9自杀基因构建出CLIP-CAR-iCasp9系统，并在体外环境下分别验证了BC-Biotin的磁珠分选功能、BC-AF647的红外显像功能以及AP20187的凋亡调控作用。在此基础上，本项目拟继续在体内模型中评估该系统的多步骤控制能力，有望在CAR T细胞生产阶段提高制备效率，并在治疗过程中监测其治疗效果以及评估其脱靶行为，继而在出现脱靶显像时，调控细胞治疗的毒副反应。本项目将为实体肿瘤的细胞治疗在高效制备、稳定监测以及调控毒性方面提供新的解决思路。

Rhabdomyosarcoma, a malignant tumor originating from embryonic mesenchymal cells, is one of the most common soft tissue sarcomas and childhood cancers. New immunotherapeutic approaches are urgently needed for metastatic rhabdomyosarcoma, which is associated with poor survival and unsatisfactory treatment outcomes. For hematological malignancies, CAR T cell therapy has achieved encouraging therapeutic effects. The wide application of CAR-T therapy in solid tumors is limited by many problems, such as lack of specific targets, insufficient production capacity, ineffective infiltration in tumor microenvironment, and severe adverse effects. In preliminary study, we have confirmed that FGFR4 could be a potential therapeutic target of rhabdomyosarcoma, combined the CLIP-tag protein and the iCaspase9 suicide gene to construct the CLIP-CAR-iCasp9 system. We have also verified the sorting function of BC-Biotin magnetic beads, the infrared imaging of BC-AF647 and the apoptosis regulation of AP20187 in vitro. In this study, we plan to continue to evaluate the CLIP-CAR-iCasp9 multi-stage control system in vivo, which is expected to improve the production efficiency, provide in vivo distribution information and manage the adverse effects of CAR T cell therapy. Thus, the CLIP-CAR-iCasp9 system in FGFR4-CAR T cells has the potential to broaden the clinical applications of cellular therapy in solid tumors.