Preclinical Evaluation Of 5-([C-11]-Methyloxy)-L-Tryptophan As A Potential Pet Molecular Imaging Probe

ObjectiveThe new tumor probe 5-([C-11]-methyloxy)-l-tryptophan ([C-11]-l-CMTP) had been found to show high uptake in tumor tissue in our previous report; however, the pharmacokinetic properties of [C-11]-l-CMTP have not been characterized. In this present study, we evaluated the potential of [C-11]-l-CMTP as a PET probe for tumor imaging.MethodsThe biodistribution of [C-11]-l-CMTP was determined in healthy mice and the incorporation of [C-11]-l-CMTP into proteins was investigated. In-vitro competitive inhibition experiments were conducted with Hepa1-6 hepatoma cell lines. [C-11]-l-CMTP PET imaging was performed on S180 tumor-bearing mice and lung tumor-bearing mice.ResultsBiodistribution studies showed high uptake of [C-11]-l-CMTP in the liver, kidney, and pancreas, but low uptake in brain. The transport assay studies in Hepa1-6 cells suggested that [C-11]-l-CMTP was mainly transported by the amino acid transport system B-0,B-+ and LAT1. [C-11]-l-CMTP was not incorporated into proteins in vitro. PET imaging showed that [C-11]-l-CMTP had high uptake in S180 fibrosarcoma tumor and lung tumor.Conclusion[C-11]-l-CMTP was not incorporated into proteins and was mainly transported by the amino acid transport system B-0,B-+ and LAT1, PET imaging showed that [C-11]-l-CMTP had high uptake in tumor models; it seemed to be a promising PET probe for tumor by LAT1 transport. Video abstract: http://links.lww.com/NMC/A70