Objective        To study the effect of thiostrepton (TST) on proliferation of and FoxM1 expression in human laryngocarcinoma Hep-2 cell line.       Methods      Proliferation inhibition rate of TST for human laryngocarcinoma Hep-2 cell line was measured by MTT reduction assay 48 h after it was used. Effect of TST at different concentrations on cell cycle of human laryngocarcinoma Hep-2 cells was assayed by flow cytometry. Expression of FoxM1 mRNA and protein in hum

an laryngocarcinoma Hep-2 cells  and effect of TST at different concentrations were detected by immunocytochemistry

RT-PCR and Western blotting

respectively.       Results      The proliferation inhibition rate of TST at the concentrations of 1

2

4

8

12 and 16 μmol/L on proliferation of Hep-2 cells was 5.27%

9.43%

20.25%

41.61%

67.96% and 96.95%

respectively

in 48 h after treatment. TST at the concentrations of 2 μmol/L and 3 μmol/L arrested Hep-2 cells at the stage G

1

/G

0

in a dose-dependent manner in 48 h after treatment (P0.05). Immunocytochemistry

RT-PCR and Western blotting showed that the expression levels of FoxM1 mRNA and protein were significantly lower in Hep-2 cells in 48 h after TST treatment (P0.05) .       Conclusion      TST significantly inhibits the proliferation of human laryngocarcinoma Hep-2 cell line

which is possibly with the down-regulated FoxM1 protein expression in the cells.