Apoptosis and Bcl-2 expression of cell line K562/AO2 treated with adriamycin in combination with hyperthermia

Objective To investigate the inhibitory effect of adriamycin in combination with hyperthermia on apoptosis and bcl-2 expression in the chronic leukemic cell line K562/AO2 in vitro.Methods The working con- centration of adriamycin against K562/AO2 determined by using methyl thiazolyl tetrazolium(MTT) assay was used to treat the chronic leukemic cell line K562/AO2 in vitro alone or in combination with hyperthermia induced using a hot water bath at 40,41 or 42℃.The inhibitory effect was evaluated by MTT assay.The apoptosis rates and bcl-2 ex- pression of K562/AO2 were determined by flow cytometry.Results The working concentration of adriamycin in the study was defined as its 50% inhibition concentration (IC50).A 60 min session of hyperthermia at 40℃,41℃or 42℃was associated with significant growth inhibition of the cell line K562/AO2.Adriamycin chemotherapy alone and with hyperthermia significantly inhibited the growth of K562/AO2.All treatments significantly increased apoptosis rates and down-regulated bcl-2 expression of the K562/AO2 cell line.Conclusion Adriamycin chemotherapy com- bined with 60 min sessions of hyperthermia showed significant suppression effect on K562/AO2 cell proliferation.The treatment can increase apoptosis rates and down-regulate bcl-2 expression.