Fig. 4

Reduced S100A9 down-regulates MAPK signaling and NF-κB signaling in OS cells. a. Three OS cell lines were pretreated with empty vectors and siRNA-S100A9 vectors, and then were tested by western blot in terms of their phosphorylation of ERK1/2 MAPK, p38 MAPK, p50 NF-κB and p65 NF-κB. Total ERK1/2 MAPK, total p38 MAPK, total p50 NF-κB and total p65 NF-κB were used as loading controls (n = 5, ^**p < 0.01; ^***p < 0.001, versus empty vectors group). b. The activity of ERK1/2 MAPK, p38 MAPK, p50 NF-κB and p65 NF-κB in the OS cells of blank groups, empty vectors groups and siRNA-S100A9 vectors groups were quantified by spectrophotometric assay (n = 9,^***p < 0.001, versus empty vectors group)