This study was purposed to explore the apoptosis-inducing effect of tetrandrine (Tet) and imatinib (IM) alone or both combined on K562/G01 cells and their mechanism. MTT assay was used to detect the inhibitory effect of drugs on cell growth, flow cytometry was used to detect the cell cycle and apoptosis rate. The expression of caspase-3/BCL-2 mRNA was determined by real time-PCR, and the expression of caspase-3/BCL-2 protein was assayed by Western blot. The results showed that after being treated by 1.0 µmol/L IM or 1.5 µmol/L Tet alone and combination of these two drugs for 48 h, the inhibitory rate was (22.74 ± 0.05)%, (20.34 ± 0.57)% and (44.28 ± 0.60)%, respectively, suggesting that inhibitory effect of two drug combination was more obvious. The arrest of cell cycle at G1/S phase could be observed after Tet treatment. Early apoptosis rate was (7.81 ± 0.16) %, (14.10 ± 0.28) % respectively after being treated by combination of 1.5 µmol/L and 3.0 µmol/L Tet with 1.0 µmol/L IM. After being treated with Tet alone, FQ-PCR and Western blot showed that the expressions of caspase-3 mRNA and caspase-3 protein were up-regulated, the expressions of BCL-2 mRNA and protein were down-regulated, the effect of both drug combination was more significant. It is concluded that IM or Tet alone can induce apoptosis of K562/G01. Combination of IM with Tet shows obvious synergistic effect, mechanism of which may associate with up-regulation of caspase-3 mRNA and protein expressions, and down-regulation of BCL-2 mRNA and protein expressions.
Apoptosis ; drug effects ; Benzamides ; pharmacology ; Benzylisoquinolines ; pharmacology ; Caspase 3 ; metabolism ; Cell Proliferation ; drug effects ; Gene Expression Regulation, Leukemic ; Humans ; Imatinib Mesylate ; K562 Cells ; Piperazines ; pharmacology ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Pyrimidines ; pharmacology