Preliminary investigation on adenovirus-mediated transferrin receptor reporter gene in colorectal cancer cell MR imaging / 中国介入影像与治疗学

ABSTRACT

Objective To explore the best multiplicities of infection (MOI),the expression of the target gene and in vitro MR imaging of adenovirus vector-mediated transferrin receptor (TFRC) reporter gene transfection of human colorectal cancer Lovo cells.Methods Lovo cells were transfected with recombinant adenovirus (Ad-TFRC) at 5,10,50,100 MOI to determine the best MOI,and quantitative real-time PCR was performed to detect the eDNA of TFRC.The transfected cells were incubated in the culture medium including Tf-USPIO of various concentrations,and were observed by Prussian blue staining,then the cell viability was evaluated via Trypan blue staining.The labeled cells were scanned with 7.0T MR T2W,T2 map,T2* map sequences,and the signal intensities were analyzed.Results Ad-TFRC were successfully transfected into Lovo cells.The best MOI was 50,and the efficiency of infection was more than 90％.The relative expression amount of TFRC in transfected cells was higher than that in control Lovo cells by real-time quantitive PCR (P＜ 0.01).Prussian blue staining showed numerous blue iron particles in transfected cells when the best labeling concentration was 1.5 μg/ml.Trypan blue staining results of transfected Lovo cells and control Lovo cells was (93.80± 1.60)％ and (95.10±2.30) ％,respectively (P＞0.05).MR imaging in vitro showed that compared with control Lovo cells,the signal intensity decreased on T2WI,T2 map and T2* map sequences in transfected Lovo cells (P＜0.05).Conclusion TFRC reporter gene can be efficiently mediated by adenovirus for expression in Lovo cells.After magnetization labeling,7.0T MR imaging of Lovo cells can be successfully achieved in vitro.