Midkine gene silencing enhances the sensitivity of liver cancer Bel/Fu cells to 5-fluoreouracil and its possible mechanism / 肿瘤

ABSTRACT

Objective: To investigate the effect of midkine (MK) gene silencing on chemosensitivity of human liver cancer 5-fluorouracil (5-Fu)-resistant cell line Bel/Fu, and to explore its possible mechanism. Methods: The specific sequence targeting MK gene (MK-siRNA) was transfected into Bel/Fu cells, then the expression levels of MK mRNA and protein were detected by real-time fluorescent quantitative PCR and Western blotting, respectively. Bel/Fu cells were transfected with MK-siRNA and treated with 5-Fu, then the proliferation and apoptosis of Bel/Fu cells were detected by MTT and FCM assay, respectively. Furthermore, the expression levels of phosphorylated-phosphoinositide 3-kinase (p-PI3K), phosphorylated-protein kinase B (p-PKB, p-Akt), nuclear factor-kappa B (NF-?B), Bcl-2, survivin and caspase-3 proteins were detected by Western blotting. Results: The expression levels of MK mRNA and protein in Bel/Fu cells transfected with MK-siRNA were significantly down-regulated (both P < 0.05). The half inhibitory concentration (IC50) of 5-Fu in Bel/Fu cells transfected with MK-siRNA was (472± 21) μg/mL, significantly lower than that in untransfected blank control group (2 035 ± 34) μg/mL (P < 0.05). The apoptotic rate of Bel/Fu cells transfected with MK-siRNA was (32.10±3.61)%, significantly higher than that in untransfected blank control group (7.90±0.91)% (P < 0.01). The expression levels of p-PI3K, p-Akt, NF-?B, Bcl-2 and survivin proteins were significantly down-regulated (all P < 0.05), while the expression level of caspase-3 was significantly up-regulated (P < 0.05) in Bel/Fu cells transfected with MK-siRNA. Conclusion: MK gene silencing can enhance the chemosensitivity of hepatocellular cancer Bel/Fu cells to 5-Fu. The mechanism may be involved in activation of PI3K/Akt signal pathway.