TABLE 2

Sorafenib synergizes with sodium valproate to kill pancreatic and liver tumor cells.

Pancreatic cancer (Mia Paca2, PANC1) and hepatoma (HEP3B) cells 12 h after plating were treated with vehicle (DMSO), sorafenib (2.25-9.00 μM), sodium valproate (0.50-1.50 mM), or with both drugs combined, as indicated, at a fixed concentration ratio to perform median dose-effect analyses for the determination of synergy. After drug exposure (48 h), the medium was changed, and cells cultured in drug-free medium for an additional 10 to 14 days. Cells were fixed, and stained with crystal violet, and colonies of >50 cells/colony were counted. Colony formation data were entered into the Calcusyn program, and combination index (CI) values were determined. A CI value of less than 1.00 indicates synergy.