Fig. 1.

Downregulation of KRAL is associated with 5-fluorouracil resistance in HCC cells. a The IC₅₀ values of 5-FU in HepG2, SMMC-7721, HepG2/5-FU, and SMMC-7721/5-FU cells. Data are expressed as the mean ± SD; columns: mean of three independent experiments; *p < 0.05, **p < 0.01. b The protein levels of Keap1 in HepG2, SMMC-7721, HepG2/5-FU, and SMMC-7721/5-FU cells were detected by western blot. GAPDH was used as a reference, data are expressed as the mean ± SD; the bar graph indicates the normalized values from at least 3 separate experiments; *p < 0.05, ^#p < 0.05 vs the respective parent cells. c qRT-PCR was performed to detect the relative expression of KRAL in HepG2 and SMMC-7721 cells treated with different non-cytotoxic doses of 5-FU, GAPDH was used as a reference, Data are expressed as the mean ± SD; columns: normalized mean values of three independent experiments; *p < 0.05, ^#p < 0.05, ^&p < 0.05. d The protein level of Keap1 in HepG2 and SMMC-7721 cells treated with different non-cytotoxic concentrations of 5-FU was analysed by western blot. GAPDH was used as a reference; data are expressed as the mean ± SD; the bar graph indicates the normalized values from at least 3 separate experiments; *p < 0.05 vs the 0 μg/mL group, ^#p < 0.05 vs the 0.05 μg/mL or 0.15 μg/mL group, ^&p < 0.05 vs the 0.1 μg/mL or 0.3 μg/mL group