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Objective: To investigate TRAIL, MG132 biological effects on lung cancer cells and related mechanisms. Method: 1. According to the relevant literature to determine the A549 lung cancer cells to study conventional cell cultures to different concentrations of TRAIL (500,250,125,62.5,31.25,15.625,7.8125,3.90625 μg / mL), MG132 (10, 5, 2.5 , 1μmol / L) intervention in 24-48h, dynamic morphological changes were observed, and 24,48 h using the MTT assay cell growth, and calculated drugs median inhibitory concentration (IC50). Take the A549 lung cancer cells in logarithmic growth phase, divided into control group, TRAIL group, MG132 group, TRAIL MG132 group to the corresponding groups of drugs were interfering with cell 48h dynamic morphological changes were observed; flow cytometry detection The cell cycle distribution and calculate the change of the rate of apoptosis; the first 48h collecting the cells in each group, cells were lysed lysis method to extract cell protein, protein blot to detect the expression of apoptosis-related proteins caspase8, caspase9 and nuclear transcription factor NF-κB expression changes. Statistical methods: the dose-response relationship between inhibition of cell growth rate and the concentration of the drug using the Spearman rank correlation analysis; differences between different groups t test was used to compare; All results are expressed in P lt; 0.05 indicates differences in statistics significance. Results: 1.MTT results show: TRAIL, MG132 in vitro lung cancer cell A549 has inhibited the growth; two drugs combined inhibition of cell growth significantly enhanced with the monotherapy group, the difference was statistically significance (P lt; 0.05); MG132 intervention cells 1h after intervention combined with TRAIL 48h cell growth inhibition rate was significantly higher (57.43%), compared with other co-administered, a statistically significant difference (P lt; 0.05), and the two drugs with each other the role index 1.42725, with a synergistic inhibition of cell growth. 2 Morphological observation: under an inverted microscope visible negative control group of lung cancer cell line A549 was short spindle adherent growth, TRAIL, MG132 intervention adherent growth of cells decreased after 48h, cell rounding, was wrinkled Fujian Medical University, 2008 Master graduate thesis shrink or even fall off characteristics, the combination of two drugs after the intervention characteristics more obvious; under a fluorescence microscope visible of TRAIL and MG132 role, the membrane was green fluorescent nuclei were weak red fluorescence, some nuclei were fragmented or plum-shaped typical features of apoptosis; combined effects of TRAIL and MG132 features of apoptosis was significantly enhanced. Flow cytometry results show that: the combination of TRAIL and MG132 for 48h, A549 cells apoptosis rate was 67.65%, with TRAIL (23.55%) by MG132 (25.91%) monotherapy group compared apoptosis rate increased significantly, and the difference was statistically significant (P lt; 0.05). Western blot results show: comparison with TRAIL single drug, two drugs in combination to interfere with the lung cancer cells A549 48h, nuclear transcription factor NF-κB expression significantly decreased (P lt; 0.05), apoptosis-related proteins The caspase8 caspase 9 expression significantly enhanced (P lt; 0.05), the difference was statistically significant. Conclusion: 1.TRAIL has induce apoptosis inhibiting the growth of lung cancer cells A549. Proteasome inhibitor MG132 inhibit the growth of A549 cells in vitro, and promote the role of apoptosis. 3.TRAIL with MG132 joint intervention can significantly enhance the sensitivity of A549 lung cancer cells to TRAIL-induced apoptosis, and effectively improve the rate of apoptosis. 4.NF-κB in TRAIL-induced apoptosis, signal transduction pathway plays an important role; TRAIL induce apoptosis via the alternative pathway activation of NF-κB, resulting in A549 lung cancer cell sensitivity to TRAIL-induced apoptosis reduce; combination of TRAIL and MG132 can increase the rate of apoptosis by inhibiting the activation of NF-κB and promote apoptosis related protein caspase8, caspase9 of expression.
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