HIFU联合包裹单纯疱疹病毒-胸苷激酶的超声微泡治疗对兔VX2肝移植瘤血管生成的影响

Effect of High-intensity Focused Ultrasound Combined with Ultrasound Microbubbles Encapsulating Herpes Simplex Virus-Thymidine Kinase on Angiogenesis of Transplanted Liver VX2 Tumor in Rabbits

目的观察高强度聚焦超声(High-intensity focused ultrasound,HIFU)联合包裹单纯疱疹病毒-胸苷激酶(Herpessimplex virus-thymidine kinase,HSV-TK)的超声微泡(Ultrasound microbubble)治疗对兔VX2肝移植瘤中缺氧诱导因子-1α(Hy-poxia inducible factor-1α,HIF-1α)、血管内皮生长因子(Vascular endothelial growth factor,VEGF)基因表达及微血管密度(Mi-crovascular density,MVD)的影响,并探讨其机制。方法复制兔VX2肝移植瘤模型,建模4周后,将荷瘤兔随机分为4组:对照组(A组),HIFU组(B组),超声辐照载基因微泡组(C组)和HIFU联合超声辐照载基因微泡组(D组)。治疗后两周观察肿瘤大小,免疫组化法检测肿瘤组织中HIF-1α和VEGF蛋白的表达及MVD,Real-time PCR检测肿瘤组织中HIF-1α和VEGF基因mRNA的转录水平。结果治疗后2周,B、C、D组肿瘤组织中HIF-1α、VEGF蛋白表达量,基因mRNA转录水平,MVD及肿瘤体积均明显低于A组(P<0.05),且D组明显低于B组和C组(P<0.05)。结论 HIFU联合包裹HSV-TK基因的超声微泡治疗可抑制肿瘤生长及肿瘤血管新生,降低残余瘤区HIF-1α和VEGF基因的表达,提高HIFU的疗效。

Objective To observe the effect of high-intensity focused ultrasound（HIFU） combined with ultrasound microbubbles encapsulating herpes simplex virus-thymidine kinase（HSV-TK） on the expressions of hypoxia inducible factor-1α（HIF-1α） and vascular endothelial growth factor（VEGF） genes in transplanted liver VX2 tumor in rabbits as well as the microvascular density（MVD） of the tumor,and investigate the relevant mechanism.Methods The rabbit model of transplanted liver VX2 tumor was copied.The rabbits 4 weeks after tumor-bearing were divided into control（A）,HIFU（B）,ultrasound microbubbles encapsulating HSV-TK/GCV（C） and HIFU ＋ ultrasound microbubbles encapsulating HSV-TK/GCV（D） groups.Two weeks after treatment,the tumor sizes in various groups were observed,the expression of HIF-1α and VEGF proteins and MVD of tumors were determined by immunohistochemical assay,and the transcription level of HIF-1α and VEGF mRNAs by real-time PCR method.Results Two weeks after treatment,the expression levels of HIF-1α and VEGF proteins,transcription levels of HIF-1α and VEGF mRNAs as well as sizes and MVDs of tumors were significantly lower in groups B,C and D than in group A（P 〈 0.05）,while in group D than in groups B and C（P 〈 0.05）.Conclusion HIFU combined with ultrasound microbubbles encapsulating HSV-TK inhibited the growth and angiogenesis of tumors,while decreased the expression levels of HIF-1α and VEGF genes and enhanced the curative effect of HIFU.