Department of Radiology, Fourth Military Medical University, Xian 710032, China.
Nanomedicine (Lond). 2012 May;7(5):691-703. doi: 10.2217/nnm.11.147.
The prostate stem cell antigen (PSCA) is broadly overexpressed on the surface of prostate cancer cells.
MATERIALS & METHODS: Anti-human PSCA monoclonal antibody (mAb 7F5) was bound to Fe(3)O(4)/Au (GoldMag) nanoparticles to serve as a PSCA-specific molecular MRI probe (mAb 7F5@GoldMag) for in vivo detection of prostate cancer cells. First, the efficacy of the antibody immobilization for the binding was assessed. Next, PC-3 (human prostate cancer cell line with PSCA overexpression) tumor-bearing mice were injected with mAb 7F5@GoldMag for MRI measurements while using mouse anti-human IgG bound to the particles (IgG@GoldMag) to serve as a nonspecific control. MRI examinations were conducted before and after injection of these probes at 6, 12 and 24 h; T2-weighted signal intensity within the tumors was measured.
Targeted binding of the mAb 7F5@GoldMag probe to PC-3 tumors was verified with optical images and MRI; selective binding was not observed for the nonspecific IgG@GoldMag probe.
MRI measurements suggest the promising efficacy of this new approach for targeted molecular imaging of prostate tumors.
前列腺干细胞抗原 (PSCA) 在前列腺癌细胞表面广泛过表达。
抗人 PSCA 单克隆抗体 (mAb 7F5) 与 Fe(3)O(4)/Au（GoldMag）纳米颗粒结合，作为用于体内检测前列腺癌细胞的 PSCA 特异性分子 MRI 探针 (mAb 7F5@GoldMag)。首先，评估了抗体固定用于结合的效果。接下来，将 PSCA 过表达的 PC-3（人前列腺癌细胞系）荷瘤小鼠注射 mAb 7F5@GoldMag 进行 MRI 测量，同时使用与颗粒结合的小鼠抗人 IgG（IgG@GoldMag）作为非特异性对照。在注射这些探针之前和之后的 6、12 和 24 h 进行 MRI 检查；测量肿瘤内的 T2 加权信号强度。
通过光学图像和 MRI 验证了 mAb 7F5@GoldMag 探针与 PC-3 肿瘤的靶向结合；未观察到非特异性 IgG@GoldMag 探针的选择性结合。
MRI 测量结果表明，这种新方法在靶向前列腺肿瘤分子成像方面具有很大的应用潜力。
