南方医科大学学报

南方医科大学学报 ›› 2021, Vol. 41 ›› Issue (5): 649-656.doi: 10.12122/j.issn.1673-4254.2021.05.03

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表达气体囊泡的大肠杆菌能安全地增强高强度聚焦超声的消融效果

蒋富杰，杨海燕，王 璐，汪瑶台，唐 瑜，王狄森，王 琦，邹建中   

  • 出版日期:2021-05-20 发布日期:2021-06-11

Escherichia coli expressing gas vesicles is safe for enhancing the ablation effect of high-intensity focused ultrasound in tumor-bearing mice

  • Online:2021-05-20 Published:2021-06-11

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摘要： 目的 探讨表达气体囊泡（GVs）的大肠杆菌增效高强度聚焦超声（HIFU）消融荷瘤小鼠肿瘤的作用及相关安全性。方法 常规饲养雌性BALB/c小鼠136只，随机选择32只构建4T1荷瘤小鼠模型，按体质量随机分为GVs组（大肠杆菌BL21(AI)-pET28a-ARG1）和对照组（PBS），检测凝固性坏死体积和肿瘤组织病理变化验证增效HIFU消融的作用。104只BALB/c小鼠，也按体质量随机分为GVs组和对照组（n=52），检测小鼠体质量变化，于静脉注射后第1、4和15天，测定白细胞、红细胞、血红蛋白和血小板计数，检测肝功ALT、AST和肾功CREA、BUN生化指标，ELISA检测TNF-α、IL-1β，检测肝、脾组织病理学变化，以评价其安全性。结果 HIFU消融效果显示GVs组凝固性坏死体积大于对照组（P<0.001），肿瘤组织病理切片显示GVs组损伤程度比对照组更高。体质量结果显示，GVs组体质量与对照组无明显差异，血常规结果显示，GVs组白细胞、红细胞、血小板和血红蛋白含量与对照组无明显差异（P1=0.59，P2=0.27，P3=0.76，P4=0.81）；肝、肾功生化指标结果显示，GVs组ALT、AST、CREA和BUN与对照组均无明显差异（P1=0.12，P2=0.46，P3=0.62，P4=0.86）；ELISA结果显示，GVs组TNF-α、IL-1β与对照组相比无明显差异（P1=0.48，P2=0.56），肝、脾组织病理切片显示GVs组与对照组相比无明显异常变化。结论 表达GVs的大肠杆菌通过自身稳定表达GVs，能够安全、有效地增强HIFU的消融效果。

关键词: 气体囊泡；大肠杆菌；肿瘤；高强度聚焦超声

Abstract: Objective To investigate the effect and safety of Escherichia coli (E.coli) expressing gas vesicle (GVs) for enhancing the efficacy of tumor ablation by high intensity focused ultrasound (HIFU) in tumor-bearing mice. Methods Thirty-two female BALB/c mice were used to establish mouse models bearing 4T1 tumor, which were randomized into GVs group [E.coli BL21 (AI)-PET28a-Arg1] and control group (PBS), and the efficacy of HIFU ablation was evaluated by examining coagulative necrotic volume and pathology of the tumors. Another 104 BALB/c mice were also randomly divided into GVs group and control group, and body weight changes of the mice were recorded on days 1, 4 and 15 after intravenous injection of E.coli containing GVs or PBS. White blood cells, red blood cells, hemoglobin and platelet counts and liver and renal function parameters of the mice were detected, and serum levels of TNF-α and IL-1β were examined using ELISA. The pathological changes in the liver and spleen were evaluated using HE staining to assess the safety of the treatments. Results HIFU ablation resulted in a significantly greater volume of coagulative necrosis and severer tissue damage in GVs group than in the control group (P<0.001). In the 104 BALB/c mice without tumor cell inoculation, intravenous injection of E.coli expressing GVs, as compared with PBS, did not significantly affect body weight or cause changes in white blood cell, red blood cell and platelet counts or hemoglobin level (P1=0.59, P2=0.27, P3=0.76, P4=0.81). The liver and kidney function parameters (P1=0.12, P2=0.46, P3=0.62, P4=0.86) and serum levels of TNF-α and IL-1β (P1=0.48, P2=0.56) were all comparable between GVs group and control group. No obvious pathological changes were detected in the liver and spleen tissues in either GVs group or the control group. Conclusion E.coli expressing GVs is safe for enhancing the ablation effect of HIFU in tumor-bearing mice.

Key words: gas vesicles; Escherichia coli; neoplasms; high-intensity focused ultrasound