Combined Effects of Sodium Valproate and Lithium Chloride on Inducing Apoptosis and Inhibiting Invasion of PC3 Cells

In this study, we aimed to investigate the combined effect of sodium valproate (SV) and lithium (Li) against viability, migration, and invasion of prostate cancer cell line. In this in vitro study, PC3 cells were treated with different concentrations of SV (2.5, 5.0, and 10 μM) and Li (2.5, 5.0, and 10 mM) either alone or in combination. Using the MTT test and annexin V/7ADD flow-cytometry, cell viability and apoptosis were assessed. Transwell chamber test was used to assess PC3 cells' invasion and migration. SV and Li alone had no significant effects on PC3 cell viability. However, the combination of SV and Li in all tested concentrations decreased the viability of PC3 cells in a dose dependent manner (P < 0.001). The combination of SV and Li (5.0 μM + 5.0 mM) increased apoptosis of PC3 cells compared with the control group (P = 0.003). Transwell assay showed that combination of SV with Li (5.0 μM + 5.0 mM) reduced the migration and invasion of PC3 cells significantly. The lack of a significant difference between the predicted and observed fractional inhibition for the effects of SV+Li suggests that SV and Li may have additive effects on lowering PC3 cell viability and invasiveness. These findings show that combined low doses of SV and Li could decrease the viability and invasiveness of the PC3 cells; therefore, it can be considered as a new strategy for the treatment of prostate cancer. However, further in vivo studies are required to confirm the results of this study.