Abstract: To investigate the effect of ailanthone (AIL) on the apoptosis of human melanoma A375 cells and its mechanism,the effect of AIL on proliferation of A375 cells was studied by MTT assay.The morphological change of A375 cells treated by AIL was observed by inverted phase contrast microscope.Hoechst 33258 staining was used to observe nuclear change of A375 cell treated by AIL.The apoptosis of A375 cells induced by AIL was analyzed by flow cytometry.Caspase-3 and caspase-9 activity was detected using commercial kits.The expression level of p-PI3Kβ (Ser1070),PI3Kβ,p-Akt (Ser473) and Akt was tested by Western blot.LY294002 was invited to prove the effect of AIL on PI3K/Akt signaling pathway.The result showed that AIL significantly inhibited the proliferation of A375 cells.Decrease of cell number and shrinkage of nuclear could be observed in A375 cells treated by AIL.The apoptosis rate of A375 cells was increased by AIL.The activity of caspase-3 and caspase-9 was elevated by AIL in A375 cells.Protein phosphorylation of PI3K and Akt was inhibited by AIL in A375 cells.PI3K and Akt phosphorylation level deceased and apoptosis rate increased more significantly by AIL co-treated with LY294002.This further noted that AIL induced A375 cells apoptosis via PI3K/Akt signaling pathway.

Key words: ailanthone, melanoma, A375 cells, apoptosis, PI3K/Akt signaling pathway