射频消融治疗对兔肝VX2肿瘤VEGF表达的影响

Effect of radio frequency ablation on vascular endothelial growth factor expression in rabbit liver VX2 tumor models

目的:探讨射频消融(RFA)对兔肝VX2肿瘤血管内皮生长因子(vascular endothelial growth factor,VEGF)表达的影响.方法:建立日本大耳白兔肝VX2肿瘤模型,随机分为3组:对照组直接处死取肝脏标本;RFA治疗(4h和24h)组于射频消融后4h和24h处死取出肝脏组织.并以正常兔肝脏组织为正常对照,通过免疫组织化学方法和逆转录聚合酶链式反应(RT-PCR)方法检测VEGF的蛋白和基因表达.结果:VX2肿瘤浸润性生长,射频后中央消融区呈现大片坏死,周围见炎性反应带,外围癌组织残留.免疫组化和RT-PCR示对照组肿瘤组织VEGF的蛋白和基因表达均高于正常组(VEGF/GAPDH基因灰度比:1.3048±0.1936vs0.8993±0.1107,P<0.05),射频消融后4h和24h表达明显下降(VEGF/GAPDH基因灰度比:0.7388±0.1503,0.8935±0.1936,均P<0.05),但不同时间段并无明显差异.结论:RFA治疗能下调肿瘤VEGF基因和蛋白水平的表达,抑制血管生成,减少血供,进而降低了复发和转移几率.

AIM： To investigate the effect of radio frequency ablation （RFA） on vascular endothelial growth factor （VEGF） expression in rabbit liver VX2 tumor models. METHODS： The liver VX2 tumor models were established by planting the tumor tissue suspen- sion into rabbits＇ liver and then divided into three groups： Control group were killed directly to obtain liver specimens; treat group were treated with RFA and executed after 4 h and 24 h randomly. And normal rabbit livers were used as the normal group. The expression of VEGF in all groups was detected by immunohistochemis- try and reverse transcriptase-polymerase chain reaction （RT-PCR）. RESULTS： VX2 liver tumor showed infiltrative growth. After RFA, large necrosis in the central ablation area, surrounded by inflammatory re- sponse belt and peripheral residual tumor tissue, was observed in the specimens from tumors. By immunohistochemistry and RT-PCR, the protein and gene expressions of VEGF in the control group were higher than those in the normal group （VEGF-mRNA/GAPDH-mRNA 1.3048 ± 0.1936 vs 0.8993 ± 0.1107, P 〈 0.05）, while those in treatment group （4 h： 0.7388 ± 0.1503; 24 h： 0.8935±0.1936） were decreased obviously as compared with the control group （both P 〈 0.05）. However, there was no significant difference in the expression of VEGF in the tumor tissue among the dif- ferent time points of the RFA group （P〉0.05）. CONCLUSION： RFA treatment can effectively down-regulate the protein and gene expression of VEGF, inhibit the angiopoiesis and reduce the blood supply, thus may reduce tumor relapse and metastasis.