Figure 7. Kinetin riboside requires adenosine kinase for activity.

(A) Kinetin riboside–induced suppression of CCND2 promoter activation in 3T3 cells is abolished by the adenosine kinase inhibitor A-134974 (2 μM). 3T3 cells containing the CCND2 promoter–LUC reporter construct were preincubated with A-134974 (2 μM) for 1 hour and were then treated with kinetin riboside (10 μM) for 16 hours; CCND2 trans-activation and viability were determined by LUC and MTT assays, respectively. ^†Specific adenosine kinase inhibitor. (B) Immunoblot of H929 MM cells showing that kinetin riboside–induced (10 μM) cyclin D suppression and caspase-9 cleavage are diminished by A-134974 (2 μM).