(A) RKO cells were treated with MAT2A siRNA (siMAT2A, 12 pM) or scrambled siRNA (Sc), and MAT2A mRNA levels were measured by real-time PCR after 48 hours. (B) SAMe levels were measured by high-performance liquid chromatography (HPLC). Results are expressed as nmol of SAMe per milligrams of protein. Apoptosis (C, D) and cell growth (E) were determined by Hoechst staining and BrdU incorporation after 48 hours, respectively. (F) Polyamine levels were measured by HPLC. Results are expressed as nmol of putrescine, spermidine and spermine per milligrams of protein. Results represent mean±SEM from 3 independent experiments performed in triplicate for all variables. *p<0.001 vs. Sc.