Fig. 4.

Comparison of the expression of the IRF1, IRF2, SOCS1 and SOCS3 genes following treatment of human tumor cell lines with either IFNα or IFNγ. Measurement of IRF1-, IRF2-, SOCS1-, and SOCS3-specific mRNA by qRT-PCR in Me10538, M14, and U87 after treatment for 24 h with either 250U/ml of IFNα or 250U/ml of IFNγ. The results are expressed as the mean ± SEM of fold change of the copy number of the IFN-treated sample relative to the untreated control in three independent experiments. The method of Student was used to evaluate the statistical significance of the differences between means of IFNγ- or IFNα-treated cell lines. The asterisks (*) indicate a p-value less than 0.05 using a two-tailed t test.