Inhibitory effect of fenbendazole on proliferation of human chronic myelogenous leukemia K562 cells / 中国病理生理杂志

AIM:To investigate the effect of fenbendazole (FBZ) on the proliferation of human chronic myelogenous leukemia (CML) cell line K562.METHODS:The CCK-8 assay was used to detect the effect of FBZ on viability of the K562 cells and normal peripheral blood mononuclear cells (PBMC).The cell growth was measured by the method of Trypan blue exclusion.The cell cycle was analyzed by flow cytometry.The cell cycle-related proteins were detected by Western blot.RESULTS:The growth of K562 was significantly inhibited by FBZ.However, it elicited little cytotoxic effect on PBMC.Furthermore, FBZ induced G2/M phase arrest and mitotic catastrophe in the K562 cells based on the changes of nuclear morphology, DNA content, mitotic marker analysis and the number of polykaryocytes.CONCLUSION:Fenbendazole significantly inhibits the proliferation of K562 cells and induces cell cycle arrest at G2/M phase by the regulation of cell cycle-related proteins.

Effect of tetrandrine on radiosensitivity of nasopharyngeal carcinoma cells / 中国病理生理杂志

AIM:To investigate the mechanism of the radiosensitizing effect of maximum non-cytotoxic doses of tetrandrine (Tet) on nasopharyngeal carcinoma cell lines CNE1 and CNE2.METHODS:The cells were treated with maximum non-cytotoxic doses of Tet (for CNE1 cells at 1.5 μmol/L and for CNE2 cells at 1.8 μmol/L),irradiation at 4 Gy,or combination of irradiation and maximum non-cytotoxic doses of Tet.The cell cycle distribution was analyzed by flow cytometry.The protein levels of γ-H2AX,cleaved caspase-3,p-CDC25C,CDK1,p-CDK1,cyclin B1,ERK and p-ERK were determined by Western blot.RESULTS:The expression of γ-H2AX was increased in CNE1 cells and CNE2 cells after combined treatment with irradiation and maximum non-cytotoxic doses of Tet.The percentages of CNE1 cells and CNE2 cells at G2/M phase in irradiation group were (18.09 ±0.42)％ and (18.48 ± 1.32)％,respectively,which were decreased to (15.88 ± 1.04) ％ and (13.80 ± 0.82) ％ in combined treatment group,respectively (P ＜ 0.05).Combined treatment enhanced the increase in the protein level of cleaved caspase-3 caused by irradiation.The protein levels of pCDC25C and p-CDK1 were increased in a dose-dependent manner by Tet treatment (P ＜ 0.05),while the expression of CDK1 showed no difference among different doses of Tet treatments.The protein levels of p-CDC25C,p-CDK1 and CDK1 showed no difference after the treatment with maximum non-cytotoxic doses of Tet.The combined treatment with irradiation and the maximum non-cytotoxic doses of Tet decreased the protein levels of p-CDC25C and p-CDK1 (P ＜0.05),increased the expression of cyclin B1,and had no influence on the expression of CDK1 （ P ＜0.05).The combined treatment resulted in an increase in the protein level of p-ERK1 (P ＜ 0.05).CONCLUSION:The maximum non-cytotoxic doses of Tet enhance the DNA damage and apoptosis in CNE1 cells and CNE2 cells caused by irradiation,and the mechanism might be associated with ending of G2/M arrest via activation of ERK/CDC25C/CDK1/cyclin B1 pathways.

Effect of tetrandrine on radiosensitivity of nasopharyngeal carcinoma cells / 中国病理生理杂志

AIM:To investigate the mechanism of the radiosensitizing effect of maximum non-cytotoxic doses of tetrandrine (Tet) on nasopharyngeal carcinoma cell lines CNE1 and CNE2.METHODS:The cells were treated with maximum non-cytotoxic doses of Tet (for CNE1 cells at 1.5 μmol/L and for CNE2 cells at 1.8 μmol/L),irradiation at 4 Gy,or combination of irradiation and maximum non-cytotoxic doses of Tet.The cell cycle distribution was analyzed by flow cytometry.The protein levels of γ-H2AX,cleaved caspase-3,p-CDC25C,CDK1,p-CDK1,cyclin B1,ERK and p-ERK were determined by Western blot.RESULTS:The expression of γ-H2AX was increased in CNE1 cells and CNE2 cells after combined treatment with irradiation and maximum non-cytotoxic doses of Tet.The percentages of CNE1 cells and CNE2 cells at G2/M phase in irradiation group were (18.09 ±0.42)％ and (18.48 ± 1.32)％,respectively,which were decreased to (15.88 ± 1.04) ％ and (13.80 ± 0.82) ％ in combined treatment group,respectively (P ＜ 0.05).Combined treatment enhanced the increase in the protein level of cleaved caspase-3 caused by irradiation.The protein levels of pCDC25C and p-CDK1 were increased in a dose-dependent manner by Tet treatment (P ＜ 0.05),while the expression of CDK1 showed no difference among different doses of Tet treatments.The protein levels of p-CDC25C,p-CDK1 and CDK1 showed no difference after the treatment with maximum non-cytotoxic doses of Tet.The combined treatment with irradiation and the maximum non-cytotoxic doses of Tet decreased the protein levels of p-CDC25C and p-CDK1 (P ＜0.05),increased the expression of cyclin B1,and had no influence on the expression of CDK1 （ P ＜0.05).The combined treatment resulted in an increase in the protein level of p-ERK1 (P ＜ 0.05).CONCLUSION:The maximum non-cytotoxic doses of Tet enhance the DNA damage and apoptosis in CNE1 cells and CNE2 cells caused by irradiation,and the mechanism might be associated with ending of G2/M arrest via activation of ERK/CDC25C/CDK1/cyclin B1 pathways.

Anti-proliferative and apoptotic effects of S1, a tetrandrine derivative, in human gastric cancer BGC-823 cells / 中国天然药物

The aim of the study was to investigate the anti-proliferation and apoptosis-inducing effects of S1, a novel tetrandrine derivative, in human gastric cancer BGC-823 cells and explore the possible mechanism of action. The anti-proliferative activity was determined by MTT assay; the induction of cell cycle arrest and apoptosis were detected by flow cytometry. Quantitative real time RT-PCR and Western blotting were used to evaluate the mRNA and protein expression levels in mitochondrial pathway. S1 significantly reduced cell viability and induced a G2/M phase arrest and apoptosis in dose- and time-dependent manner. Further studies showed that S1 increased mRNA and protein expression of Bax and the Bax/Bcl-2 ratio. Moreover, S1 decreased the protein expression of procaspase-9 and procaspase-3, suggesting that the induction of apoptosis may be related to the alteration of the ratio of Bax/Bcl-2 and the activation of caspases. These findings suggested that S1 merits further investigation as a novel therapeutic agent for the treatment of human gastric cancer.

Radiosensitization and relative mechanisms of vanillin derivative BVAN08 on human glioma U-251 cells / 中华放射医学与防护杂志

Objective To provide more convincing evidences and experimental data for exploring vanillin derivative BVAN08,6-bromine-5-hydroxy-4-methoxy-benzaldehyde,as a new anticancer drug,and to investigate the effect on the growth,radiosensitization of human glioma cell line U-251 and the relative mechanism.Methods The effect of BVAN08 on cell proliferation of U-251 and radiosensitivity to 60Co γ-rays (irradiation dose rate 2.3 Gy/min) were analyzed with MTT and colony-forming ability assay.Change in cellular morphology was observed by using light microscope.Change in cell cycle and apoptosis was detected with flow cytometry.The autophagy was observed by using TEM (irradiation dose rate is transmission electron microscope).DNA-PKcs protein level was detected through Western blot analysis.Results BVAN08 exhibited a dose- and time-dependent inhibition on the proliferation of U-251 cells during the concentration range of 10-100 mol/L (t = 1.83-3.07,P ＜ 0.05).IC50 at 48 h and 72 h after administration with BVAN08 were 55.3 and 52.7 mol/L,respectively.Obvious G2/M arrest was induced in U-251 cells after 4 h administration with BVAN08,and reached peak at 12 h.The G2/M population reached 63.3% in U-251 cells after 12 h administration of 60 μmol/L BVAN08 and kept increasing with the time,while both apoptosis and autophagic cell death were induced.The most effective radiosensitization time for BVAN08 treatment was 12 h before irradiation.The enhancement ratio of radiosensitivity was 3.14 for 20 μmol/L of BVAN08 12 h before 2 Gy irradiation.Conclusions BVAN08 can nduce apoptosis as well as autophygic cell death of U-251 cells,and sensitize U-251 cells.The mechanism of its radiosensitizing effect might be associated with the induction of G2/M arrest and inhibition of DNA-PKcs expression.BVAN08 seemed to be a romising radiosensitizing anticancer drug.