[Effects of PUVA on expression of Fas and FasL in inducing apoptosis of NB4 and K562 cells].

Objective: To explore the effects of psoralen (PSO) and long wave ultraviolet A (PUVA) on expression of Fas and FasL in apoptosis of NB4 and K562 leukemia cells.

Methods: The NB4 and K562 cells were taken as the study objects and their apoptosis ratios, ultrastructure changes and the expression of Fas and FasL were detected in order to observe the effects of PSO and UVA of wave length 360 nm on human leukemia cells. The factorial design and analysis of variance were used to analyze the interaction among the factors.

Results: All of PSO, UVA and PUVA could induce the apoptosis of NB4 and K562 cells, and the effects of PUVA were stronger than the other two. After treated with PUVA, the NB4 and K562 cells all showed obvious ultrastruture changes about apoptsis under the electron microscope. All of PSO, UVA and PUVA could increase the expression of Fas gene and protein, and decrease the expression of FasL gene and protein. Moreover, the effects of PUVA were stronger than the other two.

Conclusion: PUVA can induce the apoptosis of NB4 and K562 cells and the effects are the strongest, one of the pathway of PUVA to induce apoptosis is to upregulate the expression of Fas gene and downregulate the expression of FasL gene.