FOXM1 is overexpressed in MTX-resistant OS cells
(A) After treatment with various concentrations of MTX for 24 h, FoxM1 mRNA levels in OS cells were estimated by qRT-PCR. (B,C) After treatment with different concentrations of MTX for 24 h or 50 μM MTX for different durations, FOXM1 protein levels in OS cells were detected by western blot analysis, and β-actin was used as the loading control. (D) Cell viability assay of both MTX-sensitive and MTX-resistant OS cells using CCK-8 after 24 h of incubation with MTX at different doses. (E) FOXM1 protein levels were detected by western blot analysis, and β-actin was used as the loading control. (F) FoxM1 mRNA levels in parental and MTX-resistant OS cells. n=3, * P<0.05, ** P<0.01.