7-[2-(Cyclopropylmethoxy)-6-hydroxyphenyl]-1,4-dihydro-5-[(3S)-3-piperidinyl]-2H-pyrido[2,3-d][1,3]oxazin-2-one hydrochloride

Inhibitors of MEK (AZD6244) and IKK (BAY 65-1942) are used at their IC₅₀ concentrations, as determined by a 48 hour MTS assay, which achieve sufficient inhibition of kinase activity. MYL-R cells are treated for 24 hours with AZD6244 (5 μM), BAY 65-1942 (10 μM), or a combination of these inhibitors at the same concentrations. AZD6244 and BAY 65-1942 demonstrate synergistic inhibition of cell viability at the dose combination (5 μM AZD6244+10 μM BAY 65-1942), which correlates with IC₇₅ (CI = 0.48±0.01). Synergism is also indicated at the IC₅₀ (CI = 0.56±0.09) and IC₉₀ (CI = 0.46±0.02) dose combinations reported by the software (CI values are the mean of three independent experiments, ± standard deviation). AZD6244 and BAY 65-1942 treatment induces 2- and 1.3-fold caspase 3/7 activation, respectively, compared to the DMSO-treated cells. Treatment with a combination of AZD6244 plus BAY 65-1942 leads to a 3.2-fold increase in caspase 3/7 activity^[2].