Interferon-α Enhances 5′-Deoxy-5-Fluorouridine-Induced Apoptosis by ERK-Dependant Upregulation of Thymidine Phosphorylase
Figure 4
IFN-α upregulated the expression of TP partially by promoting ERK activation in gastric cancer cells. (a) MGC803 cells were preincubated with 20 μmol/L ERK inhibitor PD98059 for 1 h followed by treatment with 1000 IU/mL of IFN-α or the combination of 1000 IU/mL IFN-α and 250 μg/mL -DFUR. Western blot analysis of the activated levels of ERK and the expression of TP. Data were means ± SD of three independent experiments. *Pretreated with PD98059 before IFN-α alone or IFN-α -DFUR versus that untreated with PD98059 before IFN-α alone or IFN-α + -DFUR, respectively, . (b) SGC7901 and MGC803 cells were treated as described in (a). Cell apoptosis was quantified with flow cytometry. Data were means ± SD of three independent experiments. *Pretreated with PD98059 before IFN-α and -DFUR versus untreated with PD98059 before IFN-α and -DFUR, . (c) MGC803 cells were transiently transfected with ERK siRNA for 48 h, followed by 1000 IU/mL of IFN-α or 1000 IU/mL of IFN-α and 250 μg/mL of -DFUR. The expression of proteins was analyzed by Western blot. Data were means ± SD of three independent experiments. *Incubated with IFN-α alone or with IFN-α and -DFUR in siRNA ERK versus that in siRNA control, respectively, . (d) SGC7901 and MGC803 cells were transiently transfected with ERK siRNA for 48 h, followed by 1000 IU/mL of IFN-α or 1000 IU/mL of IFN-α and 250 μg/mL of -DFUR. Cell apoptosis was quantified by flow cytometry. Data were means SD of three independent experiments. *Incubated with IFN-α and -DFUR in siRNA ERK versus that in siRNA control, .
