MCF-7 cordycepin polysome profiling

3’deoxyadenosine, also known as cordycepin, has been widely researched as a potential treatment for cancer, yielding promising results in tissue culture as well as in pre-clinical models. A wide variety of mechanisms of action have been proposed, with little agreement between different studies. Here, we confirm that cordycepin triphosphate is likely to be the active metabolite of cordycepin. Data from single and high throughput experiments showed that cordycepin 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 6 cell lines. Effects of cordycepin on translation through mTOR pathway repression were detectable within 30 minutes, indicating a rapid process. Our data show that cordycepin has a broadly similar mechanism of action in all cell lines studied and indicate that its therapeutic target is a cordycepin triphosphate sensitive molecule that is required for growth factor signal transduction. MCF-7 cells were treated with DMSO or 50 μM cordycepin for 30 minutes (four replicates for each condition), RNA was separated into subpolysomal and polysomal fractions on a sucrose gradient, purified, labelled with cy5 and cy3 using a dye swap in duplicate, and microarray analysis performed.