Arsenic trioxide induces expression of Pirh2 E3 ligase.
A and B, Western blot analyses were prepared with extracts from HaCaT (A) and ME-180 (B) cells left untreated or treated with 5 μm arsenic trioxide for 3–9 h and then probed with antibodies against Pirh2 and actin, respectively. C, the level of Pirh2 transcript is increased by arsenic trioxide. RT-PCR analysis was performed with total RNAs isolated from HaCaT cells left untreated or treated with 5 mm arsenic trioxide for 6 or 12 h. Actin mRNA was amplified as a loading control. D, schematic presentation of the Pirh2 promoter luciferase reporters. E, arsenic treatment transactivates the Pirh2 promoter. The dual luciferase assay was performed with HaCaT cells that were cotransfected with 0.5 μg of a luciferase reporter (LUC) and 3 ng of pRL-SV40-Renilla vector for 24 h and then left untreated or treated with 5 μm arsenic trioxide for 8 h. *, p < 0.05.