Cell cycle arrest of synchronized human embryonic lung fibroblast exposed to benzo(a)pyrene

Objective To explore the effect of benzo(a)pyrene(Bap)on cell cycle of synchronized human embryonic lung fibrob last(HELF).Methods Treatments of 0.5% serums tarvation and 10% serumre stimulation were used to obtain cells synchronisation in G0/G1,S and G2/Ms tage.H ELF cells synchronized in specific phase after serumre-stimulation were exposed to dime thylsulfoxide,2,10 and 50μmol/LB aP for 2 hours.Cell cycle distribution and cell cycle regulation proteins such as cyclin D,cyc lin E,cyc lin A,cyc linB,P53,P21 and P16 were detecred 12hr after B aP exposure with FCM and Western Blotting methods,respectively.Results Serumstarvation and restimulation induced cells arrest in different phase and cell cycle phase change obviously 24 hr after serumre-stimulation.Cyclins expression in HEL F cells deceased from G0 phase in a time-dependent manner.BaP induced a decrease of HEL F cells in S stage.HEL F treated with Bap were a rrested in G1s tage and the expression of cyclin D decreased distinctly after serumre-stimulation of 102.2 hr.HEL F with Bap treatment 16-18 hr after serum restimulation exhibited inceases of G2 stage and P53,P21 expressions.The ratio of G0/G1 and the expressions of P53 and P21 inc reased in HELF treated with Bap 22-24 hr after the serum restimulation.Conclusion BaP activates both G1 and G2 checkpoints of HELF synchronized in specific phase and induces cell cycle a rrest.