title: Wortmannin inhibits K562 leukemic cells by regulating PI3k/Akt channel in vitro.
abstract: The inhibitory effect of wortmannin 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-kappaBp65 and IKK-kappaB 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 IC(50) 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-kappaBp65 and IKK-kappaB experienced degradation of various 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-kappaB channels).
authors: Institute of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China. wuqing1221@21cn.cn
authors: Qing
authors: Q
authors: Wu
authors: Yan
authors: Y
authors: Chen
authors: Guohui
authors: G
authors: Cui
authors: Yiquan
authors: Y
authors: Cheng
mesh_terms: D000730:Androstadienes / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D015536:Down-Regulation / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D020014:K562 Cells; D051058:Oncogene Protein v-akt / Q000187:drug effects*; D019869:Phosphatidylinositol 3-Kinases / Q000187:drug effects*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D015398:Signal Transduction / Q000187:drug effects*; D051996:Transcription Factor RelA / Q000187:drug effects; D000077191:Wortmannin
chemical_list: D000730:Androstadienes; D051058:Oncogene Protein v-akt; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D051996:Transcription Factor RelA; D000077191:Wortmannin; C498143:RELA protein, human