Figure 1.

Induction of ferritin mRNA by t-BHQ treatment is PI3K-dependent in Jurkat cells. (A) Growing Jurkat cells were treated with t-BHQ (2.5, 10, and 25 μM) or H₂O₂ (10 and 25 μM) for 24 h and ferritin H Northern blot was carried out (top). The band below 18S RNA is the ferritin H mRNA (a filled arrowhead). The hybridized bands above 28S RNA (open arrowheads) were unknown but proportionally increased by t-BHQ treatment. RNA staining with ethidium bromide is shown on the bottom for verification of the quality and comparative loading of RNA. Representative results are shown from four independent experiments. (B) Growing Jurkat cells were pretreated with 0.1% dimethyl sulfoxide (DMSO), 20 and 50 μM LY294002, 0.5 and 2 μM wortmannin, 20 and 40 μM SB203580, 10 and 25 μM U0126, or 10 μM JNK inhibitor-II for 1 h, followed by 10 μM t-BHQ treatment for 24 h, and ferritin H, ferritin L, or NQO1 Northern blot was carried out. RNA staining with ethidium bromide is shown below. Representative results and the -fold increase in mRNA expression by densitometry are shown from three independent experiments.