Targeted radionuclide therapy with RAFT-RGD radiolabelled with 90Y or 177Lu in a mouse model of αvβ3-expressing tumours
Résumé
Purpose
The αvβ3 integrin plays an important role in tumour-induced angiogenesis, tumour proliferation, survival and metastasis. The tetrameric RGD-based peptide, regioselectively addressable functionalized template-(cyclo-[RGDfK])4 (RAFT-RGD), specifically targets the αvβ3 integrin in vitro and in vivo. The aim of this study was to evaluate the therapeutic potential of RAFT-RGD radiolabelled with β− emitters in a nude mouse model of αvβ3 integrin-expressing tumours.
Methods
Biodistribution and SPECT/CT imaging studies were performed after injection of 90Y-RAFT-RGD or 177Lu-RAFT-RGD in nude mice subcutaneously xenografted with αvβ3 integrin-expressing U-87 MG cells. Experimental targeted radionuclide therapy with 90Y-RAFT-RGD or 177Lu-RAFT-RGD and 90Y-RAFT-RAD or 177Lu-RAFT-RAD (nonspecific controls) was evaluated by intravenous injection of the radionuclides into mice bearing αvβ3 integrin-expressing U-87 MG tumours of different sizes (small or large) or bearing TS/A-pc tumours that do not express αvβ3. Tumour volume doubling time was used to evaluate the efficacy of each treatment.
Results
Injection of 37 MBq of 90Y-RAFT-RGD into mice with large αvβ3-positive tumours or 37 MBq of 177Lu-RAFT-RGD into mice with small αvβ3-positive tumours caused significant growth delays compared to mice treated with 37 MBq of 90Y-RAFT-RAD or 37 MBq of 177Lu-RAFT-RAD or untreated mice. In contrast, injection of 30 MBq of 90Y-RAFT-RGD had no effect on the growth of αvβ3-negative tumours.
Conclusion
90Y-RAFT-RGD and 177Lu-RAFT-RGD are potent agents targeting αvβ3-expressing tumours for internal targeted radiotherapy.