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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.
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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.
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Objective: To investigate the inhibition effects of manumycin combined with cisplatin (DDP) on the proliferation of human ovarian cancer cell line 3AO and the growth of transplantation tumors in nude mice, and to analyze its possible mechanisms. Methods: MTT colorimetric assay was performed to evaluate the cytotoxic effect of manumycin combined with DDP on 3AO cells. The model of nude mice bearing ovarian transplantation tumor was established. The expressions of survivin, NF-κB, vascular endothelial growth factor (VEGF) and caspase-3 proteins were detected by immunohistochemical method. The cell cycle distribution and apoptosis rate were examined by flow cytometry. Results: The proliferation of 3AO cells was inhibited by manumycin in a time- and dose-dependent manner (P <0.05). The manumycin of 10, 20, 40 or 60 μmol/L could strengthen the cytotoxic effect of DDP on 3AO cells. The tumor size in nude mice of each drug-treated group was significantly smaller than that of the control (untreated) group (P <0.05). Compared with the DDP alone and the manumycin alone group, the expressions of survivin, NF-κB and VEGF proteins were significantly down-regulated while the expression of caspase-3 protein was significantly up-regulated (P <0.05) in the combination (manumycin plus DDP) group (P <0.05). The apoptosis rates were increased gradually in the control group, manumycin group, DDP group and the combination group. In each drug-treated group, the number of cells in G0/ G 1 phase was decreased significantly, while which in G2/M phase was increased significantly (P <0.05), as compared with the control group. The number of cells in S phase did not show any changes in each group. Conclusion: The combination of manumycin and DDP shows an enhanced ability to inhibit the proliferation of human ovarian cancer cells 3AO and increase their apoptosis. This effect may be associated with the down-regulation of survivin, NF-
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AIM: To investigate the anticancer effect of manumycin on abdominal metastatic breast cancer cell line-SK-BR-3 and its relationship with p38 MAPK . METHODS: The test of anticancer effect was performed by the method of MTT, apoptosis induced by manumycin and affected by SB203580, a specific p38 MAPK inhibitor, were examined by caspase-3 activity assay kit, and the protein expression was detected by immunoblotting assay. RESULTS: The inhibition rates at 24 h after treatment with manumycin of 6 ?mol/L, 18 ?mol/L, 54 ?mol/L were (7.4?3.9)%, (21.0?4.4)% and (64.7?4.1)%, respectively and showed dosage-effect relationship. Compared with the control group, the survival rates of the last two treatment groups were decreased significantly (P
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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.