Induction of ATF3 and Egr-1 mRNA gene expression by sulindac sulfide and TGZ occurs via the Erk1/2 MAPK pathway Cells were treated for 4 h with vehicle (dimethyl sulfoxide), sulindac sulfide (20 μM), or TGZ (10 μM) followed by mRNA expression for ATF3, Egr-1, and actin. Values are expressed as mean -fold change (±S.E.M.) relative to vehicle-treated cells adjusted for actin. The inhibitor PD98059 was used at 20 μM. Values from PD98059-treated cells are shown for completeness. Statistical significance is according to Bonferroni t test for multiple comparisons at the p < 0.01 level of significance on control values adjusted for actin from vehicle, sulindac sulfide (or TGZ), and sulindac sulfide (or TGZ) + PD98059-treated cells.



Egr-1 mRNA
Sulindac sulfide 7.1 ± 0.14a 21.6 ± 0.6a
Sulindac sulfide + PD98059 3.4 ± 0.05b 0.5 ± 0.03b
TGZ 37.1 ± 0.45a 32.2 ± 0.8a
TGZ + PD98059 1.5 ± 0.02b 0.1 ± 0.01b
1.2 ± 0.05
0.1 ± 0.01
  • a,b Values sharing a letter are not significantly different, whereas values with a unique letter are significantly different from vehicle-treated cells