The inhibitory effect ofwortmannin on leukemic cells and the possible mechanisms were examined. K562 cells were treated with wortmannin of various concentrations （3.125-100 nmol/L） for （0-72 h. MTT assay was used t...The inhibitory effect ofwortmannin on leukemic cells and the possible mechanisms were examined. K562 cells were treated with wortmannin of various concentrations （3.125-100 nmol/L） for （0-72 h. MTT assay was used to evaluate the inhibitory effect of wortmannin on the growth of K562 cells. Cell apoptosis was detected by both Annexin-V FITC/PI double-labeled cytometry and transmission electron microscopy （TEM）. The expression of p-Akt, T-p-Akt, NF-kBp65 and IKK-κB was determined by Western blotting and reverse transcription-polymerase chain reaction （RT-PCR）. Our results showed that wortmannin obviously inhibited growth and induced apoptosis of K562 cells in vitro in a time- and dose-dependent manner. The IC50 value of wortmannin for 24 h was 25±0.14 nmol/L. Moreover, wortmannin induced K562 cells apoptosis in a dose-dependent manner. TEM revealed typical morphological changes of apoptosis in wortmannin-treated K562 cells, such as chromatin condensation, karyopyknosis, karyorhexis and apoptotic bodies. Additionally, several important intracellular protein kinases such as p-Akt, NF-κBp65 and IKK-κB experienced degradation of vari- ous degrees in a dose-dependent manner both at protein level and transcription level when cultured with wortmannin, but the expression of total Akt showed no change. It is concluded that wortmannin can inhibit the proliferation and induce apoptosis of K562 leukemia cells possibly by down-regulating the survival signaling pathways （PI3K/Akt and NF-κB channels）.展开更多
基金supported by a grant from the National Natural Sciences Foundation of China(No.30671743)
文摘The inhibitory effect ofwortmannin on leukemic cells and the possible mechanisms were examined. K562 cells were treated with wortmannin of various concentrations （3.125-100 nmol/L） for （0-72 h. MTT assay was used to evaluate the inhibitory effect of wortmannin on the growth of K562 cells. Cell apoptosis was detected by both Annexin-V FITC/PI double-labeled cytometry and transmission electron microscopy （TEM）. The expression of p-Akt, T-p-Akt, NF-kBp65 and IKK-κB was determined by Western blotting and reverse transcription-polymerase chain reaction （RT-PCR）. Our results showed that wortmannin obviously inhibited growth and induced apoptosis of K562 cells in vitro in a time- and dose-dependent manner. The IC50 value of wortmannin for 24 h was 25±0.14 nmol/L. Moreover, wortmannin induced K562 cells apoptosis in a dose-dependent manner. TEM revealed typical morphological changes of apoptosis in wortmannin-treated K562 cells, such as chromatin condensation, karyopyknosis, karyorhexis and apoptotic bodies. Additionally, several important intracellular protein kinases such as p-Akt, NF-κBp65 and IKK-κB experienced degradation of vari- ous degrees in a dose-dependent manner both at protein level and transcription level when cultured with wortmannin, but the expression of total Akt showed no change. It is concluded that wortmannin can inhibit the proliferation and induce apoptosis of K562 leukemia cells possibly by down-regulating the survival signaling pathways （PI3K/Akt and NF-κB channels）.
