Abstract: Objective To study the mechanism of oxaliplatin combined with daunorubicin on the apoptosis of colon cancer cells. Methods Colon cancer cells HT-29 were incubated with different concentrations of oxaliplatin and daunorubicin respectively, MTT assay was used to detect cell proliferation and calculate the median inhibitory concentration.HT-29 cells were treated with half inhibitory concentration of oxaliplatin, daunorubicin and by two drugs combined. MTT assay cell proliferation ability, the colony forming ability of cells was detected by plate cloning test, cell apoptosis was detected by flow cytometry, Western blot was used to detect the expression of cleaved caspase-3, PTEN and p-Akt in cells. Results Different concentrations of oxaliplatin and daunorubicin inhibited the proliferation of HT-29 cells, the half inhibitory concentration of daunorubicin was about 0.23 μmol/L and oxaliplatin was about 40 mg/L. Daunorubicin, oxaliplatin or oxaliplatin plus daunorubicin were used to treat HT-29 cells, the proliferation of cells decreased, the ability of clone formation also reduced, the rate of apoptosis increased, the expression of cleaved caspase-3 protein increased in cells, the expression of p-Akt protein in cells decreased,the expression of PTEN protein elevated(P＜0.05). The effect of oxaliplatin combined with daunorubicin was higher than that of daunorubicin or oxaliplatin alone (P＜0.05). Conclusions Oxaliplatin combined with daunorubicin can induce apoptosis in colon cancer cells, its mechanism may be related to the regulation of PTEN/Akt signaling.

Key words: colon cancer, oxaliplatin, apoptosis, daunorubicin, PTEN