射频消融治疗对肝VX2瘤及转移肿瘤血管生成的影响

The Effect of Radio Frequency Ablation (RFA) on Tumor Angiogenesis in Liver VX2 Tumor and Metastases

目的:探讨射频消融(RFA)对兔肝VX2肿瘤及转移结节中肿瘤血管生成的影响。方法:建立兔VX2移植瘤模型,模型组直接处死,实验组于射频后4、24h处死取出肝、肺肿瘤组织。免疫组化法检测VEGF的蛋白表达和MVD,逆转录聚合酶链式反应(RT-PCR)方法检测VEGF的基因表达。结果:VX2肿瘤呈浸润生长,射频后,中央消融区细胞呈现大片坏死,周边为炎性反应带,外围癌组织残留。免疫组化结果示模型组VEGF蛋白表达及MVD均高于正常组,射频处理后肝脏残癌组织中VEGF蛋白及MVD下降,而肺组织内无明显变化;RT-PCR结果示模型组肺转移结节的VEGF/GAPDH基因表达比为1.117±0.125 4,射频消融后4h和24h,基因表达比分别为1.046 5±0.136 6,1.057 4±0.145 2,与模型组比较无明显差异,P>0.05。结论:RFA能破坏局部的肿瘤微血管,下调VEGF表达,抑制肿瘤血管生成;对于远处肿瘤血管生成,RFA治疗并无明显影响。

Objective： To investigate the effect of radio frequency ablation （RFA） on tumor angiogenesis in liver VX2 tumors and metastases. Methods： The VX2 tumor models were established and divided into three groups randomly： the mice in the control group were sacrificed following the surgery to examine samples of lung and liver tumor; those in the experimental groups were treated with RFA and then sacrificed 4h or 24h after the surgical operation to obtain the liver and lung tissues. There were 5 mice in the control group with normal organs. The protein expression of VEGF and microvessel density （MVD） was detected using immunohistochemistry and VEGF-mRNA expression was detected by reverse transcriptase-polymerase chain reaction （RT-PCR）. Results： VX2 tumor cells showed infiltrative growth. After RFA, large areas of necrosis in the central ablation area were surrounded by an inflammatory reaction zone and peripheral residual tumor was observed. Results of immunohistochemistry indicated that the protein expression of VEGF and MVD were both higher in the control group than in the experimental groups, and the expression levels in residual tumors were obviously decreased. However, lung metastases differ. RT-PCR showed that the gene grey scale of VEGF/GAPDH in lung metastases is 1.117＋0.1254, and showed no difference after RFA （1.0465±0.1366 and 1.0574±0.1452 respectively at 4h and 24h, P〉0.05）. Conclusion： RFA can downregulate MVD and VEGF expression, thus inhibiting angiogenesis. However, RFA has no influence on angiogenesis in distant tumors.