Expression of cyclin B1, but not cyclin A, was enhanced by nickel treatment. 2.5 × 105 Beas-2B cells were seeded into well of 6-well plates. After being cultured at 37°C overnight, they were treated with 0.25 mmol/L or 0.5 mmol/L NiCl2 for 48 h. RNA isolation and RT-PCR were carried out (A). 2.5 × 105 of Beas-2B cells (B), Beas-2B vector control cells, and Beas-2B DN-HIF mass1 (C) were seeded into each well of 6-well plate respectively and cultured in 10% FBS DMEM overnight. The cells were then exposed to various dosage of NiCl2 as indicated for 24 or 48 h and subjected to Western blot assay.