Abstract
Cordycepin (3' deoxyadenosine) has been widely researched as a potential cancer therapy, but many diverse mechanisms of action have been proposed. Here, we confirm that cordycepin triphosphate is likely to be the active metabolite of cordycepin and that it consistently represses growth factor-induced gene expression. Bioinformatic analysis, quantitative PCR and western blotting confirmed that cordycepin blocks the PI3K/AKT/mTOR and/or MEK/ERK pathways in six cell lines and that AMPK activation is not required. The effects of cordycepin on translation through mTOR pathway repression were detectable within 30 min, indicating a rapid process. These data therefore indicate that cordycepin has a universal mechanism of action, acting as cordycepin triphosphate on an as yet unknown target molecule involved in growth factor signalling.