Vasoactive intestinal peptide receptors (VIPRs) are members of the
G-protein-coupled receptor superfamily. These receptors are overexpressed in many common malignant
tumors and play a major role in the progression and angiogenesis of a number of
malignancies. Therefore, VIPRs may be a valuable target for the molecular imaging of
tumors and therapeutic interventions. The specific natural
ligand or its analogs can be labeled with a
radionuclide and used for
tumor receptor imaging, which could be used to visualize VIPR-related
surface protein expression in vivo and to monitor the in vivo effects of molecular drugs on
tumors. Moreover, the involvement of VIPRs in malignant transformation and angiogenesis renders them potential therapeutic targets for
cancer treatment. A variety of VIP antagonists and cytotoxic VIP conjugates have been synthesized and evaluated for VIPR-
targeted molecular therapy. The importance of VIPRs in
tumor biology and the ability to predict responses to targeted
therapy and monitor
drug interventions suggest that
VIP receptor-based imaging and treatment will be critical for the early diagnosis and management of
cancer. Here, we review the current literature regarding VIPRs and their natural
ligands and the involvement of VIPRs in
tumor growth and angiogenesis, with an emphasis on the present use of VIPRs for the molecular imaging of
tumors and
therapies targeting VIPRs.