Tumorigenecity and inactivation of p53 in Cr(VI)-transformed cells. BEAS-2B cells were chronically exposed to 0.25 μM Cr(VI) for 24 weeks. A, Cell transformation assay. Chronically Cr(VI)-exposed BEAS-2B cells and their passage-matched parent cells were used to examine cell transformation. B, C, and D, Transformed cells from single colony were picked and continued to grow. Cr(VI)-transformed cells (BEAS-2B-Cr) and passage-matched non-transformed ones (BEAS-2B) were prepared for tumorigenecity assay (B), luciferase assay (C), RT-PCR (D), and immunoblottinh (E). *, p<0.05 compared to passage-matched parent BEAS-2B cells.