Caspase-3 activity assay

Following transfection with miR-146a mimic or inhibitor, SGC-7901 cells were seeded into 96-well plates at a density of 1×10⁵ cells/well, incubated overnight and processed using a Caspase-3 Activity assay kit (Cell Signaling Technology, Inc., Danvers, MA, USA). Cells were lysed in 30 µl 1X PathScan^® Sandwich ELISA Lysis Buffer. The cell lysate was mixed with the substrate solution and incubated at 37°C in the dark for 2 h, following which the relative fluorescent was measured using a fluorescence plate reader (BioTek Instruments, Inc., Winooski, VT, USA) with an excitation wavelength of 380 nm and an emission wavelength of 420 nm.