兔肝VX2肿瘤射频消融后不同区带VEGF的表达和细胞凋亡

目的分析兔肝VX2肿瘤射频消融(RFA)后不同区带血管内皮细胞生长因子(VEGF)的表达和肿瘤细胞凋亡情况。方法将48只兔肝移植VX2肿瘤,建立动物模型,分为实验组(n=42)和对照组(n=6)。对实验组行RFA,分别在术后即刻、1天、2天、1周、2周、3周各处死7只实验兔,留存肿瘤标本,进行HE染色、VEGF检测、Annexin V-FITC/PI标记和流式细胞仪检测,观察不同时间段、不同区带的VEGF变化及细胞凋亡情况。结果实验组RFA术后针道炭化区、热凝固区和消融边界区平均VEGF值差异均有统计学意义(P均0.05);针道炭化区、热凝固区及边界区术后即刻与其他时间点间两两比较差异均有统计学意义(P均0.05);针道炭化区及热凝固区VEGF在术后即刻达高峰,术后1天~3周呈整体下降趋势,消融边界区VEGF在术后即刻到1周呈上升趋势,2周后下降。术后针道炭化区、热凝固区和消融边界区平均肿瘤细胞凋亡率与对照组比较差异均有统计学意义(P均0.05),各区带细胞凋亡率均在术后1天达高峰,后呈下降趋势。结论 RFA后针道区和热凝固区内肿瘤细胞VEGF下降和肿瘤凋亡显著,而消融交界区仍可能有存活的肿瘤细胞;在RFA后第3周时,残留肿瘤细胞的增殖能力可恢复到术前状态,此时宜进一步采取相应的治疗措施。

Expression of VEGF and apoptosis of tumor cells in different regions of VX2 tumor in rabbit liver after radiofrequency ablation

Objective To explore the expression of vascular endothelial growth factor (VEGF) and apoptosis of the tumor cells in the different regions of rabbit liver VX2 tumor after radiofrequency ablation (RFA).Methods Forty-eight experimental rabbits were implanted with VX2 tumor. After successfully established the model, the rabbits were randomly divided into control group (n=6) and RFA group (n=42). In the RFA group, 7 rabbits at each time point were killed at immediately, 1 day, 2 days, 1 week, 2 weeks, 3 weeks after RFA, and the tumor specimens were retained and performed with HE staining, VEGF, Annexin V-FITC/PI labeling, flow cytometry analysis. The changes of VEGF and apoptosis of the cells in different periods and different zones after RFA were observed.Results After the operation, the difference of the VEGF value of the needle zone, coagulation necrotic zone and junction zone had statistically significant (all P<0.05). The difference of the VEGF value in each zone between immediately and the other time points after operation by pairwise comparisons were significantly different (all P<0.05). The VEGF value of the needle zone and coagulation necrotic zone reached the peak after operation immediately, which declined from 1 day to 3 weeks after operative. And VEGF of the junction zone increased from immediately to 1 week after operation, and declined 2 weeks after operation. There were significant differences in the apoptosis rate of the three zones after RFA compared with control group (all P<0.05). The apoptosis rate in all zones were at the peak on the 1 day after operation, and then showed a downward trend.Conclusion The reduction of VEGF and apoptosis of tumor cells in the needle zone and coagulation necrotic zone are significant, but tumor remnant remains visible in the junction zone. In the third week after RFA, the proliferation of the remaining tumor cells can be recurrent to preoperative levels, which suggests that the further treatment should be performed at this period.