Effects Of Tacrolimus On Proliferation, Apoptosis, And Fluorouracil Sensitivity In Hepatocellular Carcinoma

Objective Studies were performed to investigate the effect and its mechanism of Tacrolimus (FK506) with fluorouracil (5-FU)on the apoptosis in hepatocellular carcinoma. Methods The SMMC-7721 cell used in the experiment were cultured in vitro, Flow cytometry (FCM) was used to examine the effects of 5-FU with or without FK506 on the apoptosis and cell cycle of SMMC-7721 cell. CyclinD protein was estimated by Western blotting, CyclinDlmRNAwere detected by RT-PCR, nuclear factor-KB activity of SMMC-7721 was measured by immunohistochemistry and an ELISA-based method. Results 5-FU could induce apoptosis in a concentration-dependent manner at all experimental concentrations in SMMC-7721 cell (p<0.05) , the percentage of G₀/G₁-phase cells and proliferation index (PI) increased with the concentration of 5-FU. 5-FU increased levels of CyclinD1 protein and CyclinD1mRNA. NF-κB activity were also enhanced and appeared in the nuclear fraction of cells after addition of 5-FU. Pretreatment with FK506 for 2 hour markedly enhanced the effect of 5-FU in inducing apoptosis, furthermore, FK506 inhibited nuclear factor-KB activity and decreased protein and mRNA levels of CyclinDl. Conclusion These results demonstrate that FK506 can enhance 5-FU's effect on inducing apoptosis in SMMC-7721cell, the synergic effect may be associated with Go/Gi -phase stasis by inhibiting over-expression of CyclinD1during nuclear factor-KB activity.