Figure 4
15d-PGJ2-mediated inhibition of JAK/Stat3 signalling requires the reactive cyclopentenone ring system. (A) Structure of 9,10-dihydro-15-Deoxy-Δ12,14-PGJ2 (CAY10410) and 15d-PGJ2. (B) 15d-PGJ2, but not CAY10410, abrogates constitutive JAK phosphorylation in oral SCC cells. Oral SCC9 cells were treated with NM, AG490 (50 μ M), 15d-PGJ2 (20 μ M) or CAY10410 (40 μ M) for 10 min. Cell lysates were immunoprecipitated with Jak1 antibody and Western blotted for phosphorylated (PY) and total Jak1. (C) Effect of CAY10410 on Stat3 phosphorylation. Oral SCC9 cells were treated with NM, 15d-PGJ2 (20 μ M) or CAY10410 (20 and 40 μ M) for 45 min. Cells were blotted with phospho-Stat3 antibody (Y705) and subsequently stripped and reprobed with Stat3 antibody.
