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

The transcription factor NF-kappaB has been reported to prevent cells from undergoing apoptosis as well as promote cell apoptosis. To investigate the role of NF-kappaB in Cr(VI)-induced apoptosis, two cell lines were developed from human bronchial epithelial BEAS-2B cells: IKK cells, which were stably transfected with IkappaBalpha expression vector, that have normal NF-kappaB activity, and KM cells, which were stably transfected with mutated IkappaBalpha kinase expression vector, that exhibit very little NF-kappaB 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-kappaB activation is required to prevent the cells from undergoing Cr(VI)-induced apoptosis.