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ABSTRACT:Objective To investigate the effects of ω-3 polyunsaturated fatty acids on the proliferation of human gastric cancer cell line AGS and the possible mechanisms.Methods Human gastric cancer line AGS and human microvascular epithelial cell HMEC-1 were treated with different concentrations of docosdhexaenoic acid (DHA)and eicosapentaenoic acid (EPA).The inhibition of cell proliferation was evaluated by MTT assay and cell morphology.Flow cytometry was used to detect the cell cycle change.The expressions of mitochondrial respiratory membrane protein complex Ⅰ,Ⅱ and V were analyzed with Western blot.Results DHA and EPA could markedly inhibit the proliferation of AGS in significant time-dependent and concentration-dependent manners (P 0.05).Conclusion ω-3 PUFAs can selectively inhibit the growth and proliferation of human gastric cancer cell line AGS.These effects may be as-sociated with arresting cell cycle in G0/G1 phase and inhibiting the energy metabolism of AGS cells.
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Objective To investigate the inhibitory effects of docosahexaenoic acid (DHA)and 5-fluorouracil (5-FU)in combination on human gastric cancer cell line AGS in vitro .Methods Human gastric cancer line AGS was treated with different concentrations of DHA and 5-FU alone or in combination.The inhibition of cell proliferation was evaluated by MTT assay.Dose of median (IC50 )of drugs (alone or in combination)and the combination index (CI)were calculated using the median-effect equation and the combination index equation of Chou-Talalay.Flow cytometry was used to detect the cell cycle distribution.The expression of mitochondrial respiratory membrane protein complex in AGS cells was analyzed with Western blot.Results DHA and 5-FU alone or in combination could markedly suppress the proliferation of AGS in significantly time-dependent and dose-dependent manners (P <0.05).IC50 values with DHA or 5-FU administered for 24 h and 48 h were 5 1.60 μg/mL (DHA:24 h),34.82 μg/mL (DHA:48 h),45.90 μg/mL (5-FU:24 h),and 1 6.86 μg/mL (5-FU:48 h), respectively.DHA remarkably strengthened the inhibitory effect of 5-FU and decreased IC50 of 5-FU by 3.56 -2.1 5 folds.The combination of DHA and 5-FU showed synergism.Flow cytometry showed that AGS cells treated with DHA and 5-FU were arrested in G0/G1 phase and the proportion of AGS cells in G0/G1 phase increased compared with that in the control group,DHA group and 5-FU group,while the proportion of the cells in S phase decreased significantly (P < 0.05 ).Western blot showed after treatment with DHA and 5-FU for 48 h,the expression of mitochondrial respiratory membrane protein complex was significantly decreased compared with control group,DHA group and 5-FU group (P <0.05).Conclusion DHA could act synergistically with 5-FU in inhibiting the growth of gastric carcinoma cells,and meanwhile decrease the dose of 5-FU.The mechanism may be associated with cell cycle arrest in G0/G1 phase and interference in the energy metabolism of AGS cells due to inhibition of the expression of mitochondrial oxidative respiratory chain complexes by the two compounds.
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To determine whether the pathological changes caused by injury to the spinal cord can be correlated with values obtained by the Magnetic Motor Evoked Potential (MEPs) technique, we studied spinal cords from 41 adult cats who were divided into 4 groups. The groups ranged from normal cats whose spinal cords were not compressed, to slightly, moderately and severely injured. MEPs were recorded before compression and in 30 minutes, 6 hours, 1 week, 2 week and 4 week after the compression unit was installed. Pathological changes with increased pressure were seen in blood vessels, nerve cells and fibers, Nissl substance and the central canal. A reversal of pathological changes was observed in slight or moderate injury during the 4 weeks of the experiment. Extensive injury, however, caused irreversible changes in the nerve cells with loss of motor function. The latency of MEPs at 30 minutes and 6 hours in the slightly injured group was 0.37 and 0.38 times greater than the baseline and returned to normal levels in 4 weeks. In the moderately injured group, the latency was increased 0.77 and 0.81 times and in the severely injured 1.32 and 1.36 times over the baseline. Recovery in the second group was partial and not at all in the severely injured. Thus, there appears to be good correlation between observed pathological changes, motor functions and MEPs.