Investigate Mechanism Of Inhibitory Effects Of Tetrandrine On The Proliferation Of Human Pancreatic Cancer Cell Line PANC-1

ObjectiveTo observe the effects of tetrandrine on the proliferation of human pancreatic cancer cell line PANC-1.Methods1.MTT was used to detect the medicine sensitivity of PANC-1 cells to different concentrations of tetrandrine.2.Tetrandrine-induced cell cycle arrest was detected by flow cytometry.3.Flow cytometry was used to detect the effect of tetrandrine induced apoptosis of PANC-1 cells .Results:1.The results showed that tetrandrine elicited a concentration- and time- dependent manner inhibiting proliferation of PANC-1 cells with an IC50～17 and～10μmol/L for 24 h and 72 h exposures in MTT assay. The maximum growth inhibition rate of tetrandrine was 100%, which occurred at 72 h using 80μmol/L tetrandrine.2. G1 phase cell cycle arrest of PANC-1 cells were significantly induced after tetrandrine treatment 24 h (68.19% cell population in G1 when treated by 20μ?mol/L tetrandrine). In contrast, cell population in S phase was significantly decreased to 23.82% at the same treatment. Cell population in G2/M phase can increase to 7.98% in the condition of 20μmol/L tetrandrine treatment.3.The apoptosis of PANC-1 was clearly detectable after tetrandrine treatment for 24 h (Apoptosis rate of 8.29%). Conclusion:1.Tetrandrine can effectively inhibit proliferation of human pancreatic cancer PANC-1 cells with IC50 values in the micromolar range.2.Tetrandrine significantly causes PANC-1 cells G1 phase arrest and decreases cell population in S phase. Cell population in G2/M phase also increases after tetrandrine treated for 24 h.3.Tetrandrine can induce apoptosis in PANC-1 cells.ObjectiveTo explore the possible molecular mechanisms of the inhibitory effect of tetrandrine on the proliferation of PANC-1 cells.Methods1. Real-time quantitative PCR was used to examine the changes of mRNA levels of cell cyclic associated genes, including P21cip/waf1, Cdc25A, c-myc, E2F1 and apoptotic associated gene survivin after tetrandrine treatment for 24-72 h.2. Western blot was analyzed the levels of P21cip/waf1 proteins expression in PANC-1 cells with varying concentrations of tetrandrine treatment for 24-72 h.Results1.The results of real-time quantitative PCR showed that, as compared with the controls, the mRNA levels of P21cip/waf1 increased , while Cdc25A, c-myc, E2F1 and survivin mRNA levels decreased after PANC-1 cells were treated with tetrandrine for 24 h.2.The results of western blot showed that the protein expression levels of P21^cip/waf1 increased after tetrandrine treated at early stage.Conclusion:1.Tetrandrine may be through up-regulation the mRNA and protein levels of P21cip/waf1 and down-regulation the mRNA expressions of Cdc25A, c-myc, E2F1, which leads to G1 cell cycle arrest of PANC-1.2.Tetrandrine may also down-regulate the mRNA levels of survivin which induces cell apoptosis.