Non-invasive microCT imaging characterization and in vivo targeting of BB2 receptor expression of a PC-3 bone metastasis model.
OBJECTIVE
A devastating progression of human prostate cancer is the development of bone metastasis. Animal models of bone metastasis induced by inoculating human prostate cell lines into mice are well established. Here, we report the characterization of a mouse model of prostatic bone metastasis using non-invasive microCT and targeted microSPECT imaging of bone tumors using the bombesin receptor (BB2r)-avid radiolabeled peptide, (111)In-DOTA-8-Aoc-BBN[7–14]NH(2).


METHODS
Immunocompromised mice were inoculated with human prostate cancer cells by intracardiac injection. Metastatic lesion development was monitored by serially imaging mice weekly with microCT. Mice with CT imaging-confirmed bone lesions were administered (111)In-DOTA-8-Aoc-BBN[7–14]NH(2) for microSPECT imaging of BB2r expressing lesions.


RESULTS
Metastatic bone lesions as small as 0.3 mm in diameter were detected by microCT image analysis as early as 21 days after tumor cell inoculation and had wide anatomical distribution. MicroSPECT imaging using (111)In-DOTA-8-Aoc-BBN[7–14]NH(2) successfully targeted BB2r expressing metastatic bone lesions of the tibia at day 29.


CONCLUSIONS
MicroCT imaging can accurately and non-invasively follow the onset and progression of metastatic bone lesions in mouse models of prostate cancer. Micro-CT coupled with BB2r Micro-SPECT imaging affords the opportunity to obtain a combined receptor/anatomic map of metastatic bone lesion status in this mouse model.
Harry S. Truman Memorial Veterans Hospital, Columbia, MO, USA.
Christopher T
CT
Winkelmann
Said Daibes
SD
Figueroa
Gary L
GL
Sieckman
Tammy L
TL
Rold
Timothy J
TJ
Hoffman
D000818:Animals; D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D045744:Cell Line, Tumor; D004195:Disease Models, Animal; D018450:Disease Progression; D005260:Female; D006801:Humans; D006811:Humerus / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D051379:Mice; D011471:Prostatic Neoplasms / Q000473:pathology*; D018004:Receptors, Bombesin / Q000378:metabolism*; D013977:Tibia / Q000000981:diagnostic imaging / Q000473:pathology; D015899:Tomography, Emission-Computed, Single-Photon; D055114:X-Ray Microtomography / Q000379:methods*; D023041:Xenograft Model Antitumor Assays
D018004:Receptors, Bombesin