Aim To investigate the effects of Manumycin on HL-60 myeloid leukemia cell line,and to explore the mechanism,major in investigating changes in the mitochondria of leukemia cell line in response to Manumycin.Methods Human myeloid leukemia cells HL-60 were used.The cytotoxicity was analyzed by MTT assay.Apoptosis and cellular nitric oxide(NO) were detected by flow cytometry using Annexin V andNO sensor dye.Superoxide anion was measured with a fluorescent plate reader by DHE.GSH was assayed by fluorescent Monochlorobimane.The SOD activities were assayed by colorimetric methods using WST.ATP content was measured by luciferin-luciferase bioluminescence assay.The cytosolic proteins were extracted from the cells using a digitonin buffer.The protein expression of cytochrome C and Mn-SOD were determined by Western blot.Results Manumycin resulted in viability decrease in a dose-dependent manner,and induced the generation of ROS:NO and superoxide anions.Manumycin reduced intracellular glutathione.Manumycin induced mitochondria swollen,intracellular ATP content decrease and cytochrome C release from mitochondria to cytosol.Manumycin-induced apoptosis correlated with increase in ROS.Quenching of ROS with N-acetyl-L-cysteine protected leukemia cells from the cytotoxicity of Manumycin and prevented apoptosis induction by Manumycin.Conclusions Cellular ROS generation plays an important role in the cytotoxic effect of Manumycin.Manumycin induced apoptosis through mitochondria-mediated pathway that required upstream ROS generation,change of mitochondria,and cytochrome C release.

Objective To investigate the effect of 2-methoxyestradiol(2-ME) on U937 myeloid leukemia cell line and its mechanism.Methods The experiment was divided into control group(myeloid leukemia U937 cell in RPMI 1640 culture medium with equal DMSO),2-ME-treated group,NAC-treated group,and 2-ME+NAC-treated group.The cytotoxicity was analyzed by MTT assay.Apoptosis and cellular nitric oxide(NO) were detected by flow cytometry using annexin V and NO sensor dye.Superoxide anion was measured with a fluorescent plate reader by DHE.Results Viabilities of U937 cells treated with 2-ME(0.25,0.50,1.00,and 2.00 ?mol?L-1) for 48 h were gradually reduced to 0.68?0.05,0.28?0.07,0.18?0.07,and 0.11?0.04,respectively.The differences were significant compared with control group(1.00?0.05)(P0.05).2.00 ?mol?L1 2-ME also significantly increased the mean fluorescence of NO sensor dye and superoxide anions in U937 cells compared with control group(P0.05).An markedly increase in apoptotic cells was detected after 2-ME treatment for 3 h(6.78%?1.01% vs 1.59%?0.12%,P

Objective To explore the effects of manumycin on U937 cells and its mechanisms.Methods Apoptosis was detected by flow cytometry using annexin V and propidium iodide (PI) after treatment with manumycin (2 μmol/L) for different time.The reactive oxygen species (ROS) was detected by flow cytometry using Reactive Oxygen Species Assay Kit.The expressions of PI3K,P-Akt and Akt were detected by Western blotting.Results Compared with the 0 h treatment,manumycin treatment resulted in apoptosis (P ＜ 0.05) and ROS generation (P ＜ 0.05) gradually in U937 cell lines.Furthermore,manumycin also inhibited the activation of phosphatidylinositol-3 kinase (PI3K)/Akt pathway.Moreover,NAC could decrease manumycin-induced ROS generation and inhibit the effects of manumycin on the PI3K/Akt pathway and protect U937 cells from apoptosis induced by manumycin.Conclusion Manumycin induces apoptosis in U937 human leukemia cells through the regulation of the PI3K/Akt pathway and ROS production plays a critical role in the progress.

Objective To explore the effects and the mechanism of manumycin on KAT-18 cells Methods Human ATC (anaplastic thyroid cancer) KAT-18 cells were used. The cytotoxicity was analyzed by SRB assay. Apoptosis and cellular nitric oxide were detected by flow cytometry using annexin v and NO sensor dye. Superoxide anion was measured with a fluorescent plate reader by DHE.GSH was assayed by fluorescent Monochlorobimane. The SOD activities were assayed by colorimetric methods. The protein expression of Mn-SOD was determined by western blot. Results Manumycin decreased the viability of KAT-18 cells in a dose-dependent manner. Manumycin induced apoptosis significantly and NO generation simultaneously. Manumycin also induced superoxide anions generation. Manumycin reduced intracellular GSH in a time-course manner. However , manumycin did not decrease the SOD activity after 6 h treatment and Mn-SOD expression. A delayed induction of SOD activity was observed after 24 h manumycin treatment. N-acetyl-L-cysteine blocked NO and superoxide anions generation and apoptosis induction by Manumycin. Furthermore , NAC protected KAT-18 cells from the cytotoxicity of manumycin. Conclusion Manumycin induces apoptosis and has cytotoxic effects on KAT-18 cells. Cellular NO and superoxide anions generation are required for Manumycin-induced apoptosis in KAT-18 cells.

0.05]. At 20, 30 and 40 days concentration of endostatin[(212.80?85.91) ?g/L,(293.63?62.53) ?g/L, (271.57?32.45) ?g/L, respectively] were higher than that of the control group (P

Objective:To investigate the expression of CD56 antigen in leukemia cells of the patients with acute myeloid leukemia (AML)and its relationship with the prognosis of AML, and to clarify the role of CD5 6 antigen expression in predicting the prognosis of the AML patients.Methods:171 AML (non-M3)patients aged from 14 to 60 years old,who received a IA Regimen as the first time inducing chemotherapy were chosen.Flow cytometric analysis was used to evaluate the CD56 expression in leukemia cells.COX proportional regression analysis was used to select the prognostic factors,and bivariable analysis was used to study the relationship between the positive rate of CD56 and overall survival (OS).The CD56+ group (n=52),including CD56≥50% expression group (n=39) and CD56<50% expression group (n=13),and CD56- group (n=119)were identified by the expression of CD56 antigen.The complete remission rate (CRR), the relapse rate, the median OS, the median disease-free survival (DFS)and the survival rate of patients were compared.Results:The medium OS of the patients in CD56+ group (14.2 months)was shorter than that in CD56- group (39.4 months)(P<0.05).Moreover,the medium OS in CD56≥50% group was shorter than that in CD56<50% group (11.7 months vs 20.3 months,P<0.05).The 1-year and 2-year survival rates of the patients in CD56+ group (61.5%,46.2%)were lower than those in CD56-group (75.6%,63.9%)(P<0.05).The 1-year survival rate had no significant difference between CD56≥50%group and CD56<50% group (53.8%vs 84.6%,P>0.05),while the 2-year survival rate in CD56≥50% group was lower than that in CD56<50% group (41.0%vs 61.5%,P<0.05).There were no significant differences of the CRR between CD56+ group (76.9%)and CD56- group (68.9%)as well as CD56≥50% group (58.9%)and CD56<50% group (63.5%)(P>0.05).The relapse rate and first year relapse rate of patients in CD56+ group (64.3% and 37.5%)were significantly higher than those in CD56- group (34.3% and 17.9% )(P<0.05). However,there were no significant differences of the relapse rate and first year relapse rate between CD56≥50%group (75.0% and 42.9%)and CD56<50% group (37.5% and 16.7%)(P>0.05).The DFS in CD56+ group was shorter than that in CD56- group (P<0.05).The same DFS result was also found between CD56≥50%group and CD56<50% group (P<0.05).Conclusion:The expression of CD56 antigen in leukemia cells predicts a bad prognosis in the AML patients,and the higher expression of CD56 indicates the worse prognosis.