Role and regulation of Rel/NF-κB activity in anti-immunoglobulin-induced apoptosis in WEHI-231 B lymphoma cells

Abstract

In WEHI-231 cells, anti-immunoglobulin (anti-Ig) treatment leads to both a decrease in the DNA-binding activity of p50/c-Rel/p53 protein complexes and a transient enhancement in the DNA-binding activity of p50 homodimeric complexes. These cells subsequently undergo apoptosis. Because IκB-α plays a pivotal role in the regulation of Rel/NF-κB activity, we have characterized both the nature and kinetics of the expression of IκB-α following anti-Ig-induced apoptosis in WEHI-231 cells. Anti-Ig treatment of WEHI-231 cells decreased the steady-state level of IκB-α mRNA, but enhanced the stability of IκB-α, leading to an accumulation of IκB-α in both the cytosol and nucleus. Concomitant with the increase in IκB-α expression there was a gradual decline in the nuclear expression of c-Rel. Because c-Rel plays an important role in the survival of WEHI-231 cells, these results suggest that post-transcriptional regulation of IκB-α expression might play a role in the anti-Ig-induced apoptosis in WEHI-231 cells.