Résumé
Objective To explore the inhibition role of 1 ,25 dihydroxyvitamin D3 on laryngeal cancer Hep‐2 cell proliferation and its influence on mTOR signal pathway .Methods Hep‐2 cells were treated with different concentrations of 1 ,25 dihydroxyvitamin D3 (10-8 ,10-7 ,10-6mol/L) for 24 ,48 ,72 h respectively .The proliferation situation of Hep‐2 cells was detected by the MTT meth‐od and the inhibition rate was calculated .The effect of 1 ,25 dihydroxyvitamin D3 on Hep‐2 cell cycle distribution was analyzed by flow cytometry .The influence of 1 ,25 dihydroxyvitamin D3 on mTOR signaling pathway was detected by Western blot .Results Different concentrations of 1 ,25 dihydroxyvitamin D3 could inhibit the proliferation of Hep‐2 cells ,changed the cell cycle distribu‐tion and increased the proportion of Hep‐2 cells in G0/G1 phase .The expressions of TSC1 and TSC2 protein after 1 ,25 dihydroxyvi‐tamin D3 intervention were increased compared with the control group (P<0 .01) ,while the Rheb protein expression was signifi‐cantly decreased(P<0 .01):mTOR protein and phosphorylation level were significantly decreased compared with the control group (P<0 .01) ,the decrease of mTOR protein phosphorylation was especially obvious (P<0 .01);4EBP‐1 protein expression was in‐creased compared with the control group (P<0 .01) .Conclusion 1 ,25‐dihydroxyvitamin D3 alters the Hep‐2 cell cycle distribution , affects the protein expression of mTOR signaling pathway ,thus inhibits the cell proliferation .
Résumé
Objective:To set up the rat model ofchronic intermittent hypoxia under normal pressure and studyits effect on the level of blood glucose and pancreatic islet B-cells,ultrstructure.Methods:Rats were respectively exposed to room air 4 weeks(unhandled control,UC),intermittent hypoxia 4 weeks(chronic intermittent hypoxia,CIH),intermittent hypoxia 4 weeks and then room air 4 weeks(restore hypoxia,RH).To test the fasting blood glucose of rats in each group,the fasting blood insulin and C-peptid,and then get the insulin resistance index,and observe the pancreatic islet B-cells under transmission electron microscope.Results:The level of blood glucose of the rats in the CIH group increased significantly compared with those in the UC group and RH group.There was insulin resistance and slight alteration of pancreatic islet B-cells in the CIH group,but there was no difference between UC group and RH group.Conclusion:Chronic intermittent hypoxia can lead to the pancreatic islet B-cell damage and its function disturbance,There was also insulin resistance,which causes the increased level of blood glucose of the rats in the CIH group to increase.