高强度聚焦超声治疗后残余肝癌中缺氧诱导因子的变化

Changes of hypoxia-inducible factor in residual hepatocellular carcinoma following highintensity focused ultrasound exposure in nude mice

目的探讨缺氧诱导因子（HIF1α、HIF2α）在高强度聚焦超声（HIFU）治疗后的残余肿瘤中的变化。方法建立肝癌HpG2细胞株裸鼠移植瘤模型30只，采用CZF-Ⅱ型HIFU治疗仪治疗，随机分为对照组、治疗后1d．3d、5d、1周、2周组。HE染色观察标本病理变化；免疫组化、Western bloRing和实时荧光定量PCR技术检测HIF1α、HIF2α蛋白和mRNA水平。结果HE染色表明治疗后有残余肿瘤细胞和大片坏死区域。免疫组化表明HIF1α、HIF2α蛋白在各组中出现强弱不同表达。Western bloRing和RT-PCR显示HIF1α蛋白和mRNA水平在治疗后1-3d表达逐渐升高，在3d组达到高峰，与其他组比较有统计学意义（P〈0．05），在5d、1周、2周组逐渐下降。同时，HIF2a蛋白和mRNA在治疗后1d、3d组与对照组之间无明显差异（P〉0．05），在5d、1周、2周组表达逐渐升高，与对照组之间有差异（P＜0．05）。结论HIFU治疗后的残余肿瘤，HIF1α、HIF2α在不同时间出现的变化，可能与残癌中发生的细胞凋亡和血管生成有关。

Objective To study the changes in hypoxia-inducible factor （HIF1α, HIF2α） in the residual tumor cells in nude mice bearing hepatoceUular carcinoma （HCC） following treatment with high-intensity focused ultrasound （HIFU）. Methods Thirty nude mice bearing human HCC received treatment with HIFU. At 1, 3, and 5 days and 1 and 2 weeks after the treatment, the mice were examined for pathological changes of the residual tumor with HE staining; SP immunohistochemistry, Western blotting and real-time quantitative PCR were used to detect the protein and mRNA expressions of HIFla and HIF2α in the tumor. Results HE staining revealed the presence of residual tumor cells and large necrotic areas after the treatment. Immunohistochemistry showed a gradual increment of HIF1α protein and mRNA expressions after the treatment, reaching the peak level at 3 days （P〈0.05） followed by progressive reduction at 5 days and 1 and 2 weeks. HIF2a expressions at either the protein or mRNA levels exhibited no significant changes within 3 days after the treatment （P〉0.05） but increased significantly at 5 days and I and 2 weeks （P〈0.05）. Conclusion The changes of HIFlα and HIF2α in the residual tumor after HIFU treatment in nude mice bearing HCC can be associated with tumor cell apoptosis and angiogenesis after the treatment.