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OBJECTIVE:To study the inhibitory effect of dihydrotanshinone(DTS)on human lung cancer GLC-82 cell and its mechanism. METHODS:After treated with 0(blank control),5,10,20,40,80 and 100 μg/ml DTS for 24 and 48 h,MTT as-say was used to measure the inhibition rates and IC50 of cells;cell apoptosis was detected by flow cytometry after treated with 17.85 μg/ml DTS for 12,24 and 48 h to calculate apoptotic rate;Western blot was used to detect the protein expressions of Bcl-2, Bax and Caspase-3. RESULTS:Compared with blank control group,different concentrations of DTS inhibited the proliferation of cells;24 and 48 h maximal inhibition rate were 54.48% and 64.95%,respectively;IC50 were 62.36 and 33.94 μg/ml. DTS could induce cell apoptosis in positive time dependent manner,and the range of inhibition rate was 5.6%-29.6%;Western blot showed DTS could down-regulate the expression of Bcl-2 protein and up-regulate the expression of Caspase-3 protein (P<0.01 or P<0.05). CONCLUSIONS:DTS have significant inhibitory effect on GLC-82 cells and also induce cell apoptosis,by a possible mech-anism of down-regulating the expression of Bcl-2 protein and up-regulating the expression of Caspase-3 protein.
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Aim To investigate the cytotoxic effect and mechanism of ampelopsin sodium ( AMP-Na ) on hu-man lung adenocarcinoma cell line GLC-82 alone or combined with carboplatin ( CBP ) . Methods The cytotoxic effect of human lung adenocarcinoma cell line GLC-82 was investigated by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide ( MTT ) colori-metric assay. Ultrastructure change of apoptotic GLC-82 cells was observed with transmission electron micro-scope. The changes of the cell apoptosis and the ex-pression of caspase-3 were analyzed with flow cytome-ter. Results Combined with AMP-Na, the IC50 of CBP decreased from (17. 10 ± 4. 78) mg·L-1 to tron microscope and flow cytometric analysis, the apop-tosis and necrosis ratios also increased in the combina-tion group. The necrosis ratios increased from (2. 56 ± 0. 41 )% to ( 71. 83 ± 5. 43 )% ( P<0. 01 ) . The ex-pression of caspase-3 was increased significantly after treated with AMP-Na or combined with CBP. Conclu-sions There is a synergistic cytotoxic effect on GLC-82 cells treated with AMP-Na combined with CBP. Ap-optotic cells and necrotic cells are found in GLC-82 cells treated with AMP-Na alone or combined with CBP. One of the mechanisms to induce apoptosis is probably that activation of caspase-3 mediates signal transduction pathway in cells.
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Objective To determine the sensitization of Nicotinamide (NA) on None Focused Ultrasound (NFU) on GLC-82 cells in vitro. Methods The subjectives were divided into A、B、C and D four groups, group A was negative control, group B was treated with NA, group C was irradiated with NFU, group D was treated with both NFU and NA; MTT assay was used to evaluate the cytotoxicity of NA and its sensitivity for NFU on GLC-82 cells quantified by calculating the sensitive enhancement ratios (SER); Morphologic change of cells was observed with light microscope, fluorescence microscope and scanning electron microscope;Flow cytometry was performed to determine the percentage changes of apoptosis and distributional percentage of the cell cycle of GLC-82 cells in response to NFU, NA and the effect of its intervention to NFU. Results The cytotoxicity of NA increased in a dose-dependent manner after 24-hour treatment, with the optimal dose range of 1 mg/mL~5 mg/mL. A sub-toxic dose of NA at 3 mg/ml was used in the subsequent experiments; After treatment with NA plus NFU, microvilli and filipodium of GLC-82 cells reduced, shortened and shrunk into corpuscule-shape; The apoptosis rate of group D was more than that in group B and C, with cell cycle arrested at phase S and G2.Conclusion NA can significantly enhance the effect of NFU on GLC-82 cells, which provides evidence for NA as a sensitization to NFU in clinic.
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Wild-type p53 has been shown to be involved in several aspects of cell growth control. In order to study the role of wild-type p53 in the growth of lung adenocarcinoma cell line GLC-82, recombinant p53 adenovirus vector and the control LacZ gene were constructed. Infection conditions were detected by biochemistry staining for LacZ s expression product ?-gal, immunohistochemical analysis for p53 protein expression, and PCR technique for the infected cells. The cell growth rate and cell cycle were analysed with flow cytometry. The results showed that the constructed recombinant adenovirus vector could infect cells with high level expression of (?-gal and p53 protein and p53 cDNA could be found in the infected cells. The wild-type p53 could inhibit GLC-82 cell proliferation and cause cellular death. These results indicated that wild-type p53 gene mediated by adenovirus vector might be used in the treatment of lung adenocarcinoma.