Cell proliferation, biotin vitamin

Vitamins are essential lead compounds for the development of novel radiopharmaceuticals. Many vitamin receptors such as the folate receptor are overexpressed on different tumor cell lines (Parker et al. 2005). Biotin labeled with Tc is under investigation since many years in different settings. A vitamin that has not found as much interest as hiotin is vitamin B12. Since it is a relatively large molecule, it has heen proposed to use B12 as a Trojan horse since rapidly proliferating cells and some bacterial stems show a high demand for this growth essential vitamin. While research toward labeled folate and B12 has intensified over the past couple of years, research with biotin rather slowed down. The biochemical pathways of folate and B12 are interlinked since folate delivers the -CH3 group to the apoenzyme in order to activate it toward its function in the methionine synthase cycle. 

---