Sb203850

CHMm cells were collected during the exponential growth phase by trypsinization (0.25% trypsin; Beyotime Institute of Biotechnology) and cell densities were adjusted to 1×10⁴/ml suspensions. The cells were seeded into 96-well culture plates at a volume of 200 µl/well and incubated at 37°C in 5% CO₂ for 24 h. The experimental groups were treated with different concentrations of paclitaxel (0, 0.01, 0.1 and 1 µM) and other treatments to assess synergistic effects, including 20 µM LY294002 or SB203850 (PI3K/AKT inhibitor and P38 inhibitor, respectively; both Beyotime Institute of Biotechnology) for 24 h. MTT (100 µl; 5 mg/ml; Sigma-Aldrich; Merck KGaA) was added to each well and incubated for another 4 h. The supernatants were discarded and 150 µl DMSO was added while the cells were incubated in the dark for 10 min. Optical density (OD) values was measured at a reference wavelength of 490 nm, and a detection wavelength of 570 nm. Cell viability values were calculated using the following formula: Cell viability rate (%)=(OD_{experimental group}-OD_{blank group})/(OD_{normal control group}-OD_{blank group}) ×100.