Effects of polyamine modulation on translation initiation of MCF-7 cells. MCF-7 cells were seeded, treated with DFMO for 72 h or DFMO for 48 h plus Spd for 24 h. For rapamycin, cells were treated for 72 h. For the untreated control, cells were seeded and grown for 96 h. All plates were thereafter harvested and processed for polysome analysis. (a) is a representative of polysome profiles from untreated control, 5 mM DFMO treatment, 0.1 μM rapamycin and 5 mM DFMO + 100 μM spermidine (Spd) for two independent experiments. (b) Estimation of the polysome to monosome ratio for the respective treatment for the area under curve. Values shown are mean ± range, for two independent experiments. For DFMO+Spd, the error bar is within the graph. Similar results were obtained for MDA-MB-231 cell line. Note: rapamycin treatment in this figure serves as a positive control of the effect of mTORC1 inhibition in the cancer cells.