Figure 1

15d-PGJ₂ inhibits IL-6-induced Stat3 phosphorylation in oral SCC cells. (A) Oral SCC cells were treated with normal medium (NM) or rIL-6 (20 ng ml⁻¹) for 24 h. (B) Oral SCC25 cells were treated with NM, 15d-PGJ₂ (PG 10 μ M) for 1 h or rIL-6 (20 ng ml⁻¹) for 45 min. Alternatively, cells were treated rIL-6 (20 ng ml⁻¹) for 45 min in the presence of 10, 20 or 40 μ M pretreatment with 15d-PGJ₂. (C) AG490 inhibits Stat3 constitutive phosphorylation. Oral SCC9 cells were treated with either 0.1% DMSO as vehicle (V) or AG490 (50 μ M) for 45 min, 3, 6, 12 or 24 h. (D and E) Oral SCC9 cells were either untreated or supplemented with 25 ng ml⁻¹ TGF-α for 45 min in the presence or absence of 1 h pretreatment with (D), AG490 (50 μ M) or (E) PD153035 (100 ng ml⁻¹). Cell lysates were blotted with phospho-Stat3 antibody (Y705) and subsequently stripped and reprobed with Stat3 antibody. Comparable results were obtained from other cell lines used.