Abstract:

Objective To study the effects of imatinib mesylate on the apoptosis in human melanoma cell line M14. Methods M14 cells were cultured in vitro in the presence of imatinib mesylate at three concentrations （5, 10 and 20 μmol/L） for 96 hours. Sebsequently, annexin V-FITC and propidium iodide （PI） double staining flow cytometry and terminal deoxynucleotidyl transferase （TdT）-mediated dUTP nick end labeling （TUNEL） were used to detect the cell cycle and apoptosis, respectively, DAPI staining to observe the morphological changes, and Western blot to measure the protein expressions of bcl-2 and bax in cells. Results Imatinib mesylate of the three concentrations could induce an evident increase in the apoptosis in M14 cells. Compared with untreated M14 cells, an increase of cell population in S phase was observed in imatinib mesylate-treated cells （P ＜ 0.05）, along with a decline in cell population in G2/M phases （P ＜ 0.01）. Annexin V/PI double staining and TUNEL revealed a significant increase in the rate of early apoptosis and in the acount of apoptotic cells, respectively, in M14 cells treated with imatinib mesylate of the three concentrations （all P ＜ 0.01）. After treated with imatinib mesylate of 20 μmol/L, there was a morphological change characteristic of apoptosis in M14 cells, together with an upregulated expression of bcl-2 （t = 15.46, P ＜ 0.01） and downregulated expression of bax （t = 25.53, P ＜ 0.01）. Conclusions Imatinib mesylate can interfere with the process of cell cycle of and induce the apoptosis in M14 cells, which may be mediated through mitochondrial pathway.

Key words: Melanoma, Imatinib mesylate, Apoptosis