前列腺癌移植瘤近红外荧光成像最佳成像时间的实验

Best Imaging Time of Near-infrared Fluorescence Imaging for Prostate Cancer Xenografts

目的探讨前列腺癌荷瘤裸鼠皮下移植瘤吲哚菁绿(ICG)体外近红外荧光成像的动态特征、最佳显影时间及成像机制。方法选取10只SPF级BALB/c-nu雄性裸鼠,构建人前列腺癌细胞系PC3荷瘤裸鼠模型,其中7只裸鼠尾静脉注射10mg/kgICG,分别于注射后不同时间行近红外荧光成像,观察移植瘤及全身荧光影像的动态特征,计算肿瘤背景比(TBR)。3只裸鼠同法注射10mg/kgICG,24h后剖取肿瘤组织及不同脏器和瘤旁脂肪组织进行体外近红外荧光成像。取肿瘤组织行病理切片,在荧光显微镜下观察肿瘤组织中ICG的分布。结果7只裸鼠尾静脉注射ICG后肿瘤部位荧光强度随时间的推移逐渐增强,肿瘤周围的背景荧光逐渐减弱,12h后TBR最佳。3只裸鼠各器官平均灰度值依次为:胃>大肠>小肠>肝脏>肿瘤>肾脏>瘤周脂肪组织。荧光显微镜下可见肿瘤组织有明显的绿色荧光。结论静脉注射ICG后,ICG能够通过高通透性及滞留效应,在前列腺癌皮下移植瘤中浓聚,注射后12~24h成像效果最佳。

Objective To investigate the dynamic characteristics, optimal development time and imaging mechanism of indocyanine green(ICG) in vitro near-infrared fluorescence imaging of subcutaneous xenograft tumor of prostate cancer in nude mice. Methods We selected 10 male SPF BALB/c-nu nude mice to construct PC3 tumor-bearing nude mouse models of human prostate cancer cell line. Seven nude mice were injected with10 mg/kg ICG via tail vein. Near-infrared fluorescence imaging was performed at different time after injection to observe the dynamic characteristics of the transplanted tumor and whole body fluorescence images, and the tumor-to-background ratio(TBR) was calculated. Another three nude mice were injected with 10 mg/kg ICG in the same way. After 24 h, tumor tissues, different viscera and paraneoplastic adipose tissues were dissected for near-infrared fluorescence imaging. Tumor tissues were taken for pathological section, and the distribution of ICG in tumor tissues was observed under fluorescence microscope. Results The fluorescence intensity at the tumor site of 7 nude mice injected with ICG gradually increased with time, and the background fluorescence around the tumor gradually decreased. After 12 h, TBR was the best. The average gray value of each organ of three nude mice was as follows: stomach>large intestine> small intestine>liver>tumor>kidney>peritum oral fat tissue. Under the fluorescence microscope, the tumor tissues showed obvious green fluorescence.Conclusion After intravenous ICG injection, ICG could be concentrated in subcutaneous prostate cancer xenografts through high permeability and retention effect, and the imaging effect is the best in 12-24 hours.