BACKGROUND: Kang-Lai-Te (KLT) is extracted from the traditional Chinese herbal medicine Semen Coicis, which has been used in China as an effective clinical drug for over a thousand years. It contains numerous ingredients with anti-tumor effects. In our previous studies on transplanted hepatomas in rats, KLT could stop the cells in the G2+M stage of cell cycle and then reduce the number of cells entering the stage G0 and G1, but the mechanism of the anti-proliferative effect was unknown. In this experiment, we examined whether KLT inhibits HepG2 cell growth, if so, tried to explore its mechanism.
METHODS: KLT at different concentrations was used for the treatment of hepatocellular carcinoma cells in vitro, respectively. The proliferation inhibitory rate was evaluated by MTT assay, induction of cell apoptosis rate and the protein levels of Fas and Fas ligand (FasL) were determined by flow cytometry (FCM), and the expression of Fas and FasL mRNA was detected by real-time fluorescent quantitative RT-PCR.
RESULTS: KLT produced an obvious time and dose-dependent inhibitory effect on HepG2 cells, and marked apoptosis was detected by FCM. The protein of Fas increased by 11.01%, 18.71%, 28.71% and 37.15%; the protein of FasL increased by 1.49%, 1.91%, 3.27% and 3.38% in comparison with the control (P<0.05). Real-time fluorescent quantitative RT-PCR showed that treating HepG2 cells with KLT caused the upregulation of Fas and FasL mRNA.
CONCLUSION: KLT inhibits HepG2 growth by inducing apoptosis, which may be mediated through activation of the Fas/FasL pathway.