Testing.
The tumor cell lines were seeded in defined numbers (....) in 96-well microtiter plates and then incubated at 37C, 5% CO2 and 95% humidity overnight. The test substances were made up as stock solutions (10 microM) in DMSO. The EC50 values were determined by adding the potential inhibitors diluted in quarter-logarithmic steps to the cells to result in final concentrations of 0.28 microM-50 microM.