ABSTRACT
ObjectiveTo investigate the inhibitory effect of fibroblast growth factor-21 (FGF-21) on the carcinogenesis of L02 cells induced by diethylnitrosamine (DEN).Methods L02 cells were cultured and treated with different concentrations of DEN (1,10,20,50,100,and 150 μmol/L).MTT assay was used to measure the influence of DEN on the viability of L02 cells,and an appropriate stimulation concentration of DEN (20 μmol/L) was selected for further study.The malondialdehyde (MDA) and superoxide dismutase (SOD) detection kits were used to measure the levels of MDA and SOD in L02 cells treated by DEN (20μmol/L) and normal L02 cells.Then L02 cells were divided into model control group (treated with 20μmol/L DEN and PBS),low-dose FGF-21 group (20 μmol/L DEN + 1 μmol/L FGF-21),and high-dose FGF-21 group (20 μmol/L DEN +2 μmol/L FGF-21).The levels of MDA and SOD were measured after 12 hours of cell culture.Real-time PCR and Western blot were used to measure the expression of βKlotho (KLB),and Western blot was used to measure the level of phosphorylated protein kinase B (p-AKT).The t-test was used for comparison of continuous data between two groups;an analysis of variance was used for comparison between multiple groups,and the least significant difference t-test was used for further comparison between two groups.Results There was a significant increase in the level of MDA and a significant reduction in the level of SOD after L02 cells were treated with DEN (t =9.336 and 16.281,P =0.011 and 0.004).Compared with the model control group,the low-and high-dose FGF-21 groups had a significant reduction in the level of MDA and a significant increase in the level of SOD (P ＜ 0.05),and compared with the low-dose FGF-21 group,the high-dose FGF-21 group had a significantly lower level of MDA and a significantly higher level of SOD (P =0.030 and 0.042),and there was a significant difference between two groups.The high-and low-dose FGF-21 groups had significantly higher mRNA expression of KLB than the model control group (P ＜ 0.001),and the high-dose FGF-21 group had significantly higher mRNA expression of KLB than the low-dose FGF-21 group (P ＜ 0.001),and there was a significant difference between two groups;the protein expression of KLB showed the same trend.The model control group had a significantly higher level of p-AKT than the other two groups (P ＜0.05),and the high-dose FGF-21 group had a significantly lower level of p-AKT than the low-dose FGF-21 group (P ＜ 0.05).Conclusion DEN can increase oxidative stress in L02 cells.By upregulating the expression of KLB,FGF-21 can reduce the level of p-AKT,inhibit oxidative stress in L02 cells induced by DEN,and thus inhibit the development of hepatocellular carcinoma.