PT  - JOURNAL ARTICLE
AU  - Temma, Takashi
AU  - Sano, Kohei
AU  - Kuge, Yuji
AU  - Kudo, Takashi
AU  - Kamihashi, Junko
AU  - Saji, Hideo
TI  - Achievement of MT1-MMP imaging shortly after radioligand administration by pretargeting strategy with SPECT
DP  - 2009 May 01
TA  - Journal of Nuclear Medicine
PG  - 1644--1644
VI  - 50
IP  - supplement 2
4099  - http://jnm.snmjournals.org/content/50/supplement_2/1644.short
4100  - http://jnm.snmjournals.org/content/50/supplement_2/1644.full
SO  - J Nucl Med2009 May 01; 50
AB  - 1644 Objectives Membrane type-1 matrix metalloproteinase (MT1-MMP) expressed in tumors is a potential target for evaluating the malignancy due to its critical role in metastasis and invasion. Thus, we aimed to achieve MT1-MMP imaging with SPECT in a few hours after the administration of a radioprobe. For the purpose, pretargeting strategy using streptavidin (SAv)-biotin system with anti-MT1-MMP monoclonal IgG (anti-MT1-MMP mAb) was adopted. Methods Anti-MT1-MMP mAb-SAv was obtained from biotinylated anti-MT1-MMP mAb and streptavidin. FM3A breast carcinoma implanted mice were injected with anti-MT1-MMP mAb-SAv, followed 72 h later by radioiodinated biotin, 123/125I-IBB. Biodistribution and SPECT data were obtained for 24 h. The comparison groups were injected with 125I-IBB alone or 125I-IBB pretargeted with negative control IgG-SAv. Results In the pretargeting study, rapid uptake of radioactivity was observed in the tumor with a prompt clearance from the blood (Tumor; 2.36, 1.89 and 1.06 %ID/g at 3, 6 and 24 h, Blood; 0.47, 0.26 and 0.07 %ID/g at 3, 6 and 24 h). Tumor to blood ratios were significantly higher than those for negative control pretargeting study (p<0.01). 125I-IBB alone showed negligible radioactivity in the tumor. The tumor was clearly visualized in SPECT at 3, 6 and 24 h after 123I-IBB administration pretargeted with anti-MT1-MMP mAb-SAv. Conclusions The MT1-MMP imaging was distinctly achieved in the first hours after the administration thanks to the effectiveness of the pretargeting strategy. This may provide a beneficial way to diagnose tumor malignancy in clinical settings.