兔肌肉移植瘤纳米刀、冷冻、射频消融的对比实验研究

目的探讨肌肉移植瘤纳米刀（IRE）、冷冻、射频消融术后的肿瘤凋亡、机体免疫及血管生成因子情况，观察不同微创技术对肌肉移植瘤的抗肿瘤效果，为临床应用提供一定的实验依据。 方法兔肌肉移植瘤模型8只，并随机分为正常对照组、纳米刀治疗组、冷冻治疗组及射频治疗组，每组2只。动态观察治疗过程中新西兰大白兔的生命体征以及治疗后并发症，术后24 h全部处死，分离血浆及血清检测，取瘤块包埋切片，HE染色，免疫组织化学方法检测Bcl-2、HSP70和VEGF在肌肉移植瘤中的表达，并运用Tunel法检测细胞凋亡。 结果肉眼观肿瘤表面血管丰富，触之质地软；各组术后治疗区域可见明显凝固性坏死改变，冷冻及射频术后临近肌肉组织充血水肿明显。HE染色显示纳米刀组治疗区域边界清晰，冷冻及射频术区仍可见部分存活细胞。Tunel结果显示纳米刀治疗组可以明显增加肿瘤细胞凋亡，各治疗组均可通过升高血浆Caspase-3水平及降低术区Bcl-2表达促进肿瘤组织凋亡，升高血浆TNF-α水平激发机体抗肿瘤免疫，同时促使血浆VEGF因子分泌短期内升高；肿瘤组织术区边缘HSP70及VEGF因子表达水平各组不一。术后血清学检测结果显示各组治疗后新西兰大白兔的肌酸激酶水平升高，CTnI及肝肾功能未见异常。 结论纳米刀、氩氦刀冷冻、射频均能够通过直接消融、诱导细胞凋亡、产生特异的抗肿瘤免疫效应来抑制兔肌肉移植瘤的生长，且治疗方法安全、有效。纳米刀在诱导细胞凋亡、周围重要脏器的保护及治疗时间短均有明显优势，为其进一步的临床应用提供了动物实验依据。

Comparative study of Nano knife,cryoablation, radiofrequency ablation in the muscle xenografts in rabbits

ObjectiveTo investigate the apoptosis, immunity and angiogenesis factor changes of rabbits after irreversible electroporation (IRE), cryoablation, radiofrequency ablation (RFA) of muscle can-cer xenografts, and to observe the antitumor effect and security of diversiform minimally invasive tech-niques for muscle cancer xenografts. MethodsEight muscle cancer xenograft models were randomly di-vided into IRE, cryoablation, RFA and control group, each group contained 2 rabbits. All the rabbits were executed after 24 hours. Liver, kidney function and creatinekinase were tested. ELISA methods were used to detect CTnI, Caspase-3, TNF-α and VEGF levels in the plasma. Tunel assay was used to detect the apoptosis of tumor tissue. Immunohistochemistry was applied to detect Bcl-2, HSP70 and VEGF expres-sion in muscle cancer xenografts. ResultsRich blood vessels were showed on the tumor surface, with soft texture. Obvious coagulation necrosis and edema were found in the adjacent muscle tissue. HE stain-ing showed a clear borderline between the necrotic and normal area in the IRE group, visible liver cells in the cryoablation and RFA group. Tunel assay showed that IRE can significantly increase the apoptosis in muscle cancer cells compared with other groups. Each group could promote tumor apoptosis by increasing plasma Caspase-3 level and reducing Bcl-2 expression in the treatment area, inspired the antitumor im-munity by elevating plasma TNF-α level and induced to the elevation of plasma VEGF secretion in the short time after treatment, HSP70 and VEGF factor expression were variant in edge of the treatment area. Post-treatment serological test showed that liver, kidney functions and CTnI were within the normal range, except for significant higher levels of creatine kinase. ConclusionsIRE, cryoablation, and RFA can in-hibit the growth of liver tumors via ablating directly, inducing apoptosis, producing specific anti-tumor im-mune response, it is safe and effective. IRE has advantages in the induction of apoptosis, protection of im-portant viscera nearby and short ablation time. This study may support further clinical application of IRE on human beings with the evidence from animals.