Cell proliferation assay

Viability of PANC-1 cells following treatment with nimesulide was evaluated using an MTT assay, as previously described (20). Briefly, 5×10³ cells/well (100 µl) were seeded in 96-well plates with different concentrations of nimesulide (0, 25, 50, 100, 200 and 400 µmol/l). DMSO was used as the control treatment. Following incubation at 37°C for 48 h, 20 µl MTT (5 mg/ml) was added to each well followed by incubation at 37°C for 4 h. DMSO was utilized to dissolve the purple formazan and the absorbance was measured at a wavelength of 490 nm using a microplate reader (Synergy HTX; BioTek Instruments, Inc., Winooski, VT, USA). The results are expressed as inhibition rates according to the following formula: Inhibition rate (%)=1-(OD treatment-OD blank)/(OD control-OD blank) ×100%.