Growth-inhibiting and apoptosis-inducing effects of Tanshinone II A on human gastric carcinoma cells

To explore the effects of Tanshinone It A on the proliferation, apoptosis and gene expression of p53 and bcl-2 in human gastric carcinoma MKN-45 cells. Cell count and MTT assay were used to study the proliferation-inhibiting effect of Tanshinone II A on MKN-45 cells. The effect of Tanshinone II A on the cell cycle and apoptosis of MKN45 cells were examined by propidium iodide (PI) staining and flow cytometry. Semi-quantitative RTLPCR was used to further verify the expression of p53 and bcl-2 gene after exposure to Tanshinone II A in MKN45 cells. The results showed that Tanshinone II A significantly inhibited the growth and proliferation of MKN45 cells in a dose- and time-dependent manner (P<0.05). Tanshinone It A arrested MKN-45 cells in G2/M phase which led to an obvious accumulation of G2/M phase cells while decreased number of G(0)/G(1) phase cells. This resulted in apoptosis of MKN45 cells and the apoptosis rate was as high as 43.91% after treatment with 2.0 mu g/mL Tanshinone II A for 96 h. It was also found that Tanshinone II A up-regulated expression of p53 gene and down-regulated expression of bcl-2 gene. The cytostatic and antiproliferative effect of Tanshinone II A makes it a promising anticancer agent for the treatment of gastric carcinoma.