Cell proliferation assay

H3122, LLC, and A549 cells were seeded in 96 well plates at 5000 cells/well. Cells were treated with TAE684 for 2 h before exposure to 4 Gy of irradiation. Cell confluence was monitored by time-lapse microscopy as previously described using IncuCyte ™ Zoom (Essen BioScience) with a 10X objective for 72 h [27]. In addition, fluorimetric measurement was performed using the CyQUANT^® Direct Cell Proliferation Assay (Life Technologies) according to manufacturers’ instruction (3 Fountain Drive Inchinnan Business Park, Paisley PA4 9RF, UK). In brief, cells proliferation was quantified 72 h post treatment using 2X detection reagent (11.7 mL PBS, 48 μL CyQUANT® Direct nucleic acid stain and 240 μL CyQUANT® Direct background suppressor I). Signal intensities after incorporation of fluorescent CyQuant dye were measured at 485/520 nm filter set by Infinite M200 Microplate reader (Tecan). The signal intensity from treated groups was normalized to the one of vehicle groups.