Investigation of a vitamin B12 conjugate as a PET imaging probe.

Academic Article


  • Nutrient demand is a fundamental characteristic of rapidly proliferating cells. Vitamin B12 is vital for cell proliferation; thus neoplastic cells have an increased demand for this essential nutrient. In this study we exploited the vitamin B12 uptake pathway to probe the nutritional demand of proliferating cells with a radiolabeled B12 derivative in various preclinical tumor models. We describe the synthesis and biological evaluations of copper-64-labeled B12 -ethylenediamine-benzyl-1,4,7-triazacyclononane-N,N',N''-triacetic acid (B12 -en-Bn-NOTA-(64) Cu), the first example of a B12 derivative for positron emission tomography (PET) imaging. Small-animal imaging and pharmacological evaluation show high tumor uptake ranging from 2.20 to 4.84%‚ÄČID g(-1) at 6 h post-administration. Competition studies with excess native B12 resulted in a 95% decrease in tumor accumulation, indicating the specificity of this radiopharmaceutical for B12 endocytotic transport proteins. These results show that a vitamin B12 PET radiopharmaceutical has potential utility for non-invasive imaging of enhanced nutrient demand in proliferating cells.
  • Published In

  • ChemMedChem  Journal
  • Keywords

  • CD320, cobalamin, positron emission tomography, radiochemistry, vitamins, Animals, Cell Line, Tumor, Coordination Complexes, Copper Radioisotopes, HCT116 Cells, Heterocyclic Compounds, Humans, Melanoma, Experimental, Mice, Mice, Nude, Positron-Emission Tomography, Radiopharmaceuticals, Tissue Distribution, Tomography, X-Ray Computed, Transplantation, Heterologous, Transplantation, Homologous, Vitamin B 12
  • Digital Object Identifier (doi)

    Author List

  • Ikotun OF; Marquez BV; Fazen CH; Kahkoska AR; Doyle RP; Lapi SE
  • Start Page

  • 1244
  • End Page

  • 1251
  • Volume

  • 9
  • Issue

  • 6