Effect of peroxisome proliferator activated receptor γ agonist rosiglitazone on proliferation and apoptosis of MG63 cells

Objective To investigate the influence of peroxisome proliferator-activated receptor γ (PPARγ) agonist rosiglitazone on the growth and apoptosis of human osteosarcoma MG63 cells.Methods MG63 cells were cultured with rosiglitazone at the concentrations of 0.5,5.0,50.0,100.0 μmol/L respectively,and the controls were not treated.The methyl thiazol tetrazolium (MTT) method was used to detect the growth inhibition rate at 24,48 and 72 h.Flow cytometry (FCM) was used to examine the proliferation status of the cells at 24 h and 48 h which have been treated with 0,0.5,5.0,50.0 μ mol/L rosigltazone.TUNEL assay was used to detect apoptosis in 0.5 μmol/L rosiglitazone group at 48 h,and apoptotic index (AI) was calculated.Results The results of MTT showed:( 1 ) In all rosiglitazone groups at 24,48 and 72 h respectively,there was significant difference in the inhibition rate among the groups (P ＜0.01 ),and with the prologation of time,the inhibition rate had an increased tendency.At 24,48 and 72 h,the inhibition rate ( ％ ) in 0.5 μmol/L rosiglitazone group was 30.10 ± 0.01,46.70 ± 0.01 and 48.80 ± 0.02 respectively; (2) At any time point,there was significant difference in the inhibition rate among the groups (P ＜0.01 ).The inhibition rate at the same time point was decreased in a concentrationdependent manner during the range from 0.5 to 50.0 μmol/L.The results of FCM revealed:( 1 ) There was significant difference in the cell-cycle distributions among the groups ( P ＜ 0.01 ).The proportion of cells in G0/G1 phase in any rosiglitazone group was higher than in control group at 24 or 48 h,and the highest proportion was achieved in 0.5 μmol/L group.The proportion of cells in G0/G1 phase was decreased with the increase of rosiglitazone concentrations.In all rosiglitazone groups,the proportion of cells in S phase was lower than in control group,and the proportion of cells in S phase was increased with the increase in rosiglitazone concentration.These suggested rosiglitazone had a significant effect on the arrest of the cell cycle in G0/G1 phase.(2) At different time points,there was no significant difference in cell-cycle distributions (F =0.36,P ＞ 0.05 ).The result of TUNEL indicated:The apoptosis rate in 0.5 μmol/Lrosiglitazone group ( 14.33 ± 3.35 ) ％ was significantly higher than in control group ( 2.82 ± 0.63 ) ％(P ＜0.01 ),cell nucleus pyknosis and apoptotic bodies were observed by microscopy in all rosiglitazone groups.Conclusion PPARγ agonist rosiglitazone can inhibit the proliferation of MG-63 cells significantly,inducing the arrest in the G1 phase and apoptosis. Key words: Rosiglitazone;  Peroxisome proliferator activated receptor γ;  Osteosarcoma; Apoptosis