Cell viability assay

Lenvatinib was purchased from Selleck Chemicals (cat. no. S5240) and dissolved in dimethyl sulfoxide. Cell viability was determined using Cell Counting Kit-8 (CCK-8; Dojindo Molecular Technologies, Inc.) assay. Human GBC-SD and NOZ cells were seeded onto 96-well plates at a density of 5×10³ cells/well. After 24 h, the medium was removed and replaced with medium containing 0, 10, 20, 40 or 80 µM lenvatinib for different times (0, 24, 48 and 72 h). Following treatment, the cells were incubated with 10 μl CCK-8 solution in a 5% CO₂ incubator at 37 °C for 1 h. The OD values were then obtained by measuring the absorbance at a wavelength of 450 nm using a micro-plate reader (Thermo Fisher Scientific, Inc.).