循环血游离Shope病毒DNA含量与兔VX2肿瘤18F-FDG PET/CT影像表现的相关性分析

The Correlation between Cell-Free Shope Virus DNA Circulating in Plasma and ^(18)F-FDG PET/CT Imaging in VX2 Tumor-Bearing Rabbits

目的:探讨循环血中Shope病毒DNA含量与兔VX2肿瘤18F-FDG PET/CT影像学特征间的关系及其临床意义。方法:采用组织块接种法建立兔VX2肿瘤模型,并行18F-FDG PET-CT观测肿瘤大小及糖代谢相关值,实时定量荧光探针PCR法检测肿瘤组织及血浆中Shope病毒特征性DNA片段含量。结果:移植前外周血中未检测出Shope病毒特异性DNA片段;移植后2周,VX2肿瘤组织和循环血中均可以检测到特征性Shope病毒DNA片段。瘤体内DNA含量明显高于循环血中含量。循环血Shope病毒DNA含量与FDG-PET的最大标准摄取值(SUVmax)明显呈正相关(r=0.943,p=0.005),但与肿瘤体积相关性尚不明确(r=0.657,p=0.156)。结论:循环血Shope病毒DNA有望作为一种潜在的VX2肿瘤标志物,其廉价、无创的特性,有望在肿瘤的早期诊断和预后随访中发挥优势。

Objective： To investigate the relationship between 18F-FDG PET/CT imaging characteristics and circulating cell-free shope virus DNA copies, and to explore its clinical values. Methods： The VX2 tumor models in rabbit were established by transplanting VX2 tumor mass into leg muscles, and the shope virus DNA in tumor tissues and plasma was quantified by a quantitative real-time quantitative polymerase chain reaction （PCR） method. Results： Before tumor transplantation, no viral DNA was detected in peripheral blood; 14 days after transplantation circulating shope virus specific DNA fragments could be detected. Concentration of shope virus DNA in tumor tissue （mean （4.9± 1.9）× 10^6 copies/L） was significantly higher than that in the plasma （mean （1.3± 0.9）× 10^3 copies/L）. There is a positive association between circulating shope DNA level and 18F-FDG-PET/CT maximum standard uptake value, but no significant association was observed between plasma shope virus DNA level and VX2 tumor size. Conclusion： Cell-free shope viral DNA in circulating plasma may be a tumor-marker of VX2 tumor animal model for cancer research, and circulating cell free tumor specific DNA may be proposed as a novel and early detectable bio-marker as well as an inexpensive and noninvasive assay for cancer management.