Figure 4.

(A) Lack of Stat6 activation in human glioblastoma cell lines. T98G, GRE, and M007 cells were treated with human IL-4 (50 ng/ml) or PV (500 μM) for 30 min or left untreated. WCE prepared from these cells were subjected to EMSA with the N₆-GAS probe. WCE from PV-treated Daudi cells was used as positive control for activated Stat6. (B) Stat6 activation by PV or IL-4 in T98G cells expressing full-length human IL-4Rα protein. Two representative clones of T98G cells that stably express the full-length IL-4Rα (T98G/F1 and T98G/F2) and one stable clone (T98G/T1) expressing a truncated IL-4Rα (the N-terminal 404 amino acids lacking the Stat6 docking sites), all under the simian virus 40 promoter, were treated with human IL-4 (20 ng/ml) or PV (200 μM) for 30 min or left untreated. WCE prepared from these cells were used in EMSA with an N₆-GAS probe.