FSHR is an appealing target for cancer theranostics. Radiolabeled FSH1 and its derivatives have shown potential to in vivo detect FSHR expression. However, moderate labeling yields (similar to 50% nondecay-corrected) may partially limit their wide use. Ga-68 is an excellent PET nuclide due to availability, nearly quantitative reaction, and short physical half-life. In this study, Ga-68 labeled FSH1 peptide was developed for imaging of FSHR in cancers. In vitro studies and MicroPET imaging were performed in PC-3 prostate tumor model. [Ga-68] Ga-NOTA-MAL-FSH1 can be produced within 20 min with 93.2 +/- 2.1% yield and the radiochemical purity was greater than 95%. It showed that [Ga-68] Ga-NOTA-MAL-FSH1 possessed FSHR binding affinities. The tracer was stable in PBS and human serum for at least 2 hours. MicroPET imaging revealed that the PC-3 xenografts were clearly visualized and the tumor uptakes were 1.87 +/- 0.10, 1.26 +/- 0.06, and 0.71 +/- 0.10% ID/g at 0.5, 1 h, and 2 h postinjection. The corresponding tumor to blood and tumor to muscle ratios were 1.77 +/- 0.70, 7.94 +/- 1.35, and 10.37 +/- 1.16 and 7.42 +/- 0.46, 26.13 +/- 2.99, and 36.40 +/- 2.54, respectively. FSHR binding specificity was also demonstrated by reduced tumor uptake of [Ga-68] Ga-NOTA-MAL-FSH1 after coinjecting excess unlabeled FSH1 peptide. The favorable characters of [Ga-68] Ga-NOTA-MAL-FSH1 such as convenient synthesis and specific tumor uptake warrant its further investigation for FSHR expression imaging.
[1]Jiangsu Inst Nucl Med, Key Lab Nucl Med, Minist Hlth, Jiangsu Key Lab Mol Nucl Med, Wuxi 214063, Jiangsu, Peoples R China.
[2]Jilin Univ, Dept Radiol, China Japan Union Hosp, Changchun 130033, Jilin, Peoples R China.
[3]Nanjing Med Univ, Nanjing 210029, Jiangsu, Peoples R China.
[4]Zhengzhou Univ, Zhengzhou 450001, Henan, Peoples R China.
(8.0+极速模式)