Troglitazone Ketone Treatment Of Thyroid Cancer In Vitro Studies

Part 1: Troglitazone inhibited growth of papillary thyroidcarcinoma cells IHH-4 in vitroObjective: To investigate the effects of troglitazone on growth ofpapillary thyroid carcinoma cell line IHH-4.Methods: Papillary thyroid carcinoma cell line IHH-4 was incubatedwith 20,10,5,2.5,0μmol/L troglitazone and observed at different time.The cell viabilities were measured through dimethylthiazol-diphenyltet -razolium bromide (MTT) assay.Results: Troglitazone inhibited proliferation of thyroid carcinoma cells indose-dependent and time-dependent pattern (P＜0.05).Conclusion: Troglitazone significantly inhibits growth of papillarythyroid carcinoma cells in vitro.Part 2: Troglitazone arrested the G₁/S transition of papillarythyroid carcinoma cell IHH-4Objective: To investigate the effects of troglitazone on the cell cycle ofpapillary thyroid carcinoma IHH-4.Methods: Papillary thyroid carcinoma cell line IHH-4 was incubatedwith 0 or 10μmol/L troglitazone for 24 h, the cell cycles of the stimulatedcells were analyzed by flow cytometer.Results: After treated by 10μmol/L troglitazone for 24 h, the proportionof cells in G₀/G₁ phase increased significantly (P＜0.05) compared withcontrol group.Conclusion: Troglitazone could inhibit the growth of thyroid carcinomacell IHH-4 through arresting the G1/S phase transition of thyroidcarcinoma cell. Part 3: Troglitazone up-regulated the expression of cell cyclerelated gene p27Objective: To investigate the effects of troglitazone on the expression ofcell cycle related gene Cyclin D₁, p27 and p21 in papillary thyroidcarcinoma cell line IHH-4.Methods: Papillary thyroid carcinoma cells IHH-4 was incubated with 0or 10μmol/L of troglitazone and the expression of Cyclin D₁, p27 andp21 mRNA was evaluated by semi-quantitative RT-PCR at 4, 8, 12, 24 h.Results: The p27 mRNA expression was up-regulated at 4 h and reachedhighest peak at 12 h, but Cyclin D₁ and p21 mRNA did not changesignificantly.Conclusion: Troglitazone inhibits growth of thyroid carcinoma cells byarresting the G₁/S phase transition, which is related with the up-regulationof p27 gene.