Minigastrin

Minigastrin (also mini gastrin) is a form of gastrin. Its sequence is H-Leu-Glu-Glu-Glu-Glu-Glu-Ala-Tyr-Gly-Trp-Met-Asp-Phe-NH2.

Minigastrin is a potential therapeutic agent for thyroid carcinoma by targeting cancer-promoting cholecystokinin receptors.

Applications
Peptide Receptor Radionuclide Therapy (PRRT)

A radioactively labeled analogue of minigastrin, PP-F11, conjugated with NOTA, DOTA, or NODAGA, was studied to view the effects they have on peptide receptor radionuclide therapy (PRRT) and cancer cell tracing. When mice with CCK2 tumors were injected with 64Cu-labeled DOTA-PP-F11, NOTA-PP-F11, and NODAGA-PP-F11, the mice labeled with NOTA displayed a tumor uptake of 7.20 ± 0.44% ID/g and a high tumor-to-blood ratio. Further studies are being investigated on how to reduce the background levels to obtain clearer images.

The inhibition of rapamycin complex 1 improves the tumor uptake of radioactively labeled minigastrin. Treatment of A431/CCKBR tumor cells were assessed with DOTA-PP-F11N. This treatment in combination with RAD001 in mice, resulted in an average size tumor reduction of about 0.3 cm³ in comparison to the control group which had an average tumor size of 0.97 cm³. The treatment group also had a higher survival rate where the control group median life span was 19.5 days and the group that received treatment had an average life span of 43 days.