Non-invasive monitoring of carcinogenesis in N-nitrosodiethylamine induced liver cancer

Molecular imaging based on reporter gene expression allows tissue-specific events or processes to be measured using the bioluminescence imaging (BLI) reporter gene expression vector controlled by specific enhancer/promoters. Alpha-fetoprotein (AFP), which is a tumor marker, is a serum glycoprotein that is expressed normally by fetal liver and yolk-sac cells, as well as in trace amounts in the fetal gastrointestinal tract. The serum concentration of AFP decreases rapidly after birth and its expression is repressed in adults. Approximately 80% of HCC patients show an increase in the AFP level. Therefore, AFP has been used for many years as a diagnostic and prognostic serum marker for HCC and transgenic system for AFP was proposed as a valuable tool for elucidation of mechanism of transcriptional regulation during liver development and hepatocarcinogenesis. In this study, firefly luciferase (fLuc) expressing transgenic mice controlled by the AFP enhancer/ promoter (enh/promoter) were produced to screen for the development of AFP-producing liver cancer. These models are expected to be useful for monitoring agents or drugs that modulate the AFP level as well as for measuring the specific signaling events important for liver cancer development