Abstract
Positron emission tomography(PET) is an imaging of interaction between radio-labeled molecular probes and bioactive proteins/genes. Targets of PET are, mRNA, protein or reporter gene products, and appropriate radio-labeled molecular probes should be designed for the corresponding targets.For the detection of gene expression at mRNA level, antisense-oligo concept is applicable. However, radio-labeled antisense-oligo for in-vivo hybridization imaging is quite demanding. There are two approaches for the detection of gene expression at protein level, namely detection of target protein itself, or use of reporter gene system. As an example, FDG as a molecular probe for radiation therapy monitoring will be demonstrated using molecular biological findings in radiation therapy monitoring. The latter approach uses a general radio-ligand–reporter gene system, which requires an introduction of a reporter gene in addition to a target gene. As an example, estrogen receptor ligand binding domain and F-18-estradiol are demonstrated to be a candidate for gene-reporter system.These tactics in nuclear medicine will bring new information and approaches in the field of molecular and cellular medicine. [J Physiol Sci. 2007;57 Suppl:S21]
