前列腺干细胞抗原特异性MR分子探针体外成像实验研究

MRI of prostate stem cell antigen specific MR molecular probe in human prostate cancer at 3.0 T:in vitro experimental study

目的探讨本实验室构建的前列腺干细胞抗原(PSCA)特异性MR分子探针7F5@GoldMag用于体外前列腺癌细胞MR成像的可行性。方法利用3.0T磁共振扫描仪建立MR扫描序列,观察不同浓度的金磁微粒MR成像情况,探讨MR可分辨的最低浓度;培养人前列腺癌细胞系PC-3和人肝癌细胞系SMMC-7721(后者为对照组),将这两种细胞分别与7F5@GoldMag、无关抗体@GoldMag交叉配对,37℃孵育1h;对各组细胞进行T2WI扫描并分别测量其信号强度,采用单因素方差分析比较各组之间信号强度的差异。结果GoldMagTM-CS稀释至1:640与1%琼脂糖凝胶相比,T2WI序列信号强度差异有统计学意义;7F5@GoldMag标记不同细胞系行MR扫描结果提示,7F5@GoldMag可显著降低PC-3细胞T2WI信号,而对SMMC-7721MR信号无显著影响。非特异抗体偶联的GoldMag对两种细胞MR信号均无显著影响。结论本实验室构建的以PSCA为靶向分子的MR探针7F5@GoldMag可特异性降低PC-3细胞的T2WI信号,从而为下一步体内MR成像实验奠定了基础。

Objective： To investigate the feasibility of in vitro MRI of 7F5@GoldMag probe in prostate cancer on a clinical 3.0 T MR system. Materials and Methods： GoldMagTM-CS nanoparticles solution in different concentration was scanned to ascertain the lowest concentration that can be detected by MR system. Prostate cancer cell line PC-3 and hepatoma cell line SMMC-7721 were cultured （hepatoma cell line SMMC-7721 was control group）. The two cell lines were cross-matched with 7F5@ GoldMag and non-related IgG@GoldMag. Then, the mixture was incubated at 37℃ for l hour. T2WI was obtained and the signal intensity was measured in each group. Statistical analysis were performed to assess the statistical differences of signal intensity by using one-way ANOVA with SPSS 11.5 software package as parameters were normally distributed, P〈0.05 was considered as statistically significant difference. Results： The T2WI signal intensity of GoldMagTM-CS was significantly lower than that of agarose gel even if the former was diluted by 640 times. 7F5@ GoldMag could specifically decrease T2WI signal intensity of PC-3 cells in vitro. Conclusion： 7F5@GoldMag has target-directed enhancement effect in prostate cancer cell lines in vitro by using a clinical 3.0 T MR scanner.