NF-κB prevents cells from undergoing Cr(VI)-induced apoptosis

The transcription factor NF-κB has been reported to prevent cells from undergoing apoptosis as well as promote cell apoptosis. To investigate the role of NF-κB in Cr(VI)-induced apoptosis, two cell lines were developed from human bronchial epithelial BEAS-2B cells: IKK cells, which were stably transfected with Iκ-Bα expression vector, that have normal NF-κB activity, and KM cells, which were stably transfected with mutated Iκ-Bα kinase expression vector, that exhibit very little NF-κB activity. With Cr(VI) stimulation, KM cells, but not IKK cells, exhibited substantial cell death. Cell morphological and TUNEL analyses indicated that the KM cells showed apoptotic features. These results suggest that NF-κB activation is required to prevent the cells from undergoing Cr(VI)-induced apoptosis.