Objective: To study the effect of TSP02, a triterpenoid saponin compound from Ardisia japonica, on proliferation and metastasis of in vitro induced human hepatoma HepG2 cells and its molecular mechanism.
Method: MTT assay was performed to detect the inhibitory effect of TSP02 of different concentrations on proliferation of human hepatoma HepG2 and normal human hepatic cell HL-7702 cells. The changes in cell cycle and apoptotic of processed HepG2 and HL-7702 cells were detected by using flow cytometry. The effect of TSP02 on expression levels of CDK1, 2, 4, apoptosis-related protein Caspase-8, metastasis-related TGF-beta 1 and E-cadherin was measured by western blot. Wound-healing assay and transwell assay were performed to detect the changes in the metastasis of TSPO2-processed HepG2.
Result: TSP02 significantly inhibited the proliferation of HepG2 cells, with notable time dependence and concentration dependence, but without remarkable effect on normal human liver HL-7702 cells. Compared with the control group, TSP02 processed for 24 h could eliminate HepG2 cells in S stage, significantly increase the cell apoptotic rate. Furthermore, TSP02 was capable of down-regulating the expression of multiple CDK1, 2, 4, and TGF-beta1, and up-regulating the expression and activity of Caspase-8, without significant effect on cycle and apoptotic rate of normal human liver HL-7702 cells. Additionally, TSP02 caused metastasis and invasiveness HepG2 cells, while down-regulating liver cancer invasiveness-related TGF-beta 1 and E-cadherin.
Conclusion: TSP02 selectively promotes apoptosis of liver cancer cell HepG2, and inhibits its metastasis and invasiveness. TSP02's in vitro antineoplastic activity is related to the changes in cycle and apoptosis proteins, and the regulation in the expression of invasiveness-related TGF-beta 1 and E-cadherin.