Cell viability assay

Cell viability was quantitated using CellTiter-Glo® Luminescent Cell Viability Assay (Promega Corporation, Madison, WI, US) according to manufacturer instructions. Subconfluent cells in culture were collected and transferred to 96-well white-walled flat bottom plates at 1,500-5,000 viable cells in 100μl suspension per well. Cells were incubated overnight at 37°C, and then exposed to increasing concentrations of pevonedistat up to 3μM for 72 hrs. Then, 100μl of CellTiter-Glo® reagent was mixed in each well and incubated for 10 min, followed by luminescence detection using a plate reader (BiotekSynergy2, Winooski, VT, USA). Cell viability curves were derived from the raw luminescent data and used to determined IC₅₀ values.