微泡增强低频超声空化抑制裸鼠前列腺癌移植瘤

【】　目的　观察低频超声（20kHz）辐照联合静脉注射微泡造影剂SonoVue对裸鼠前列腺癌（Du145）移植瘤的抑瘤效应，并探讨其可能的抑瘤机制。　方法　通过细胞移植和瘤块移植方法建立24只裸鼠前列腺癌Du145移植瘤模型，随机分为超声微泡组、单纯超声组、单纯微泡组和对照组，每组各6只。超声微泡组尾静脉注射0.2mLSonoVue的同时对瘤体行20kHz超声辐照，辐照强度200mW/cm2；单纯超声组尾静脉注射生理盐水0.2mL，同时超声辐照2min；单纯微泡组尾静脉注射SonoVue0.2mL同时行假照，各组均隔天1次，共3次，对照组不做任何处理。治疗后测量瘤体大小，绘制瘤体生长曲线，计算抑瘤率。首次治疗后14d剥离瘤体，通过光学显微镜、电子显微镜观察肿瘤组织病理改变。免疫组织化学方法观察CD34阳性染色血管，计算肿瘤微血管密度（microvesseldensity，MVD），比较各组间MVD的差异。　结果　24只裸鼠均成功植瘤。治疗后超声微泡组瘤体体积均数明显小于其他3组（P<0.05），抑瘤率为62.7%。光学显微镜下超声微泡组瘤体组织大部分损伤坏死，电子显微镜下超声微泡组肿瘤内微血管的内皮细胞损伤，线粒体肿大，基底膜断裂。超声微泡组瘤体内CD34阳性染色微血管数减少，其MVD值显著低于其他各组。　结论　20kHz低频超声辐照联合微泡造影剂SonoVue可有效抑制裸鼠人前列腺癌移植瘤的生长，其抑瘤机制可能是通过超声空化效应破坏肿瘤的微血管实现的。【Abstract】　Objective　Toinvestigatetheanti-tumoreffectinducedbylow-frequencyultrasound(20kHz)radiationcombinedwithintravenousinjectionofmicrobubblesonhumanprostatecarcinomaxenograftinnudemice,andtodiscussitsprobablemechanism.　Methods　Humanprostatecarcinomaxenograftmodelin24nudemicewereestablishedwithhumanprostatecarcinomaDu145cellsinoculationandsub-graftthroughmice,whichwererandomlydividedintoultrasound+microbubble,ultrasound,microbubble,andcontrolgroup,with6miceineachgroup.Intheultrasound+microbubblegroup,0.2mLSonoVuewasinjectedintravenously,followedby20kHzultrasoundexposureof200mW/cm2ateveryotherdayfor3timestotally.Miceintheultrasoundgroupandthemicrobubblesgroupwereonlytreatedwithultrasoundradiationandmicrobubblesinjection,respectively.Thevolumeofgrosstumorswasmeasured,andtumorgrowthcurvewasdrawn.Theratioofanti-tumorgrowthwascalculated.Themiceweresacrificed14daysafterthelastultrasoundexposure.Specimensoftheexposedtumortissueswereobtainedandobservedpathologicallyunderlightmicroscopeandtransmissionelectronmicroscope.CD34positivevesselswerecountedinallthetumorslicesbyimmunohistochemistry,andthemicro-vesselsdensity（MVD）ofthetumorwasalsocalculated.　Results　Du145prostatetumormodelwassuccessfullyestablishedinallthemice.Theaveragegrosstumorvolumeoftheultrasound+microbubblegroupwassignificantlowercomparedwiththeothertwogroupsaftertreatment(P<0.05),andtheratioofanti-tumorgrowthwas62.7%.Histologicalexaminationshowedsignscellinjuryintheultrasound+microbubblegroup.Electronmicroscopicexaminationrevealedthattheendotheliumofvesselsinthetumorwasinjured.TheamountofCD34positivevesselsandMVDoftheultrasound+microbubblegroupwaslessthanthatoftheothertwogroups.　Conclusion　Thelow-frequencyultrasoundof20kHzexposurecombinedwithmicrobubblescanbeusedtoablatehumanprostatecarcinomaxenograftinnudemice,whichisprobablyrealizedthroughmicro-vesselsdestroyedbycavitationeffectofultrasound.