NTR1 targeted imaging with ¹⁸F-DEG-VS-(Ac)NT

Objectives Neurotensin receptors (NTRs) have been suggested to play key roles in cancer growth and survival. This work aims to develop a ¹⁸F labeled PET agent for NTR1 targeted imaging of various cancer types.

Methods Acetate was introduced to the amino end of Cys-NT peptide, which was then reacted with ¹⁸F-vinyl sulfone (¹⁸F-DEG-VS). In vivo PET scans were carried out using nude mice bearing HT29, BXPC3 or Colo205 xenografts.

Results (Ac)Cys-NT could react with ¹⁸F-DEG-VS efficiently with >90% yield based on HPLC integration. The radiochemical purity of the ¹⁸F-DEG-VS-(Ac)NT was >98%. Noninvasive microPET demonstrated that ¹⁸F-DEG-VS-(Ac)NT had NTR-specific tumor uptake in subcutaneous HT-29, BXPC3, and Colo205 xenografts. Receptor specificity was successfully demonstrated by blocking experiment.

Conclusions ¹⁸F-DEG-VS-(Ac)NT demonstrated specific tumor uptake and good tumor to background contrast in colorectal and pancreatic cancer models. ¹⁸F-DEG-VS-(Ac)NT is a promising agent for NTR1 targeted PET imaging.