Fig 7. Combined ATRA and MEKi treatment adds reduced viability.

Relative viability of MPNST cells after combination therapy (day 5) was assessed by MTT assay. MPNST cells were treated with ATRA (light grey) and MEKi (dark grey) alone or in combination (striped). PD0325901 combination treatment is shown in the upper panel, U0126 combination treatment in the lower panel. A significant reduction of viability in the combination therapy group was found for T265 cells and S462 cells with both inhibitors, compared to mono-treated cells. Bars represent mean values of repeated (3–5 times) measurements in each cell line). NSF1 cells displayed no additive effects due to combination-therapy, neither with PD0325901 nor with U0126, as well as a very weak response to monotherapy.