Anthrax lethal toxin (LeTx) shows potent mitogen-activated protein kinase pathway inhibition and apoptosis in melanoma cells that harbor the activating V600E B-RAF mutation.
Anthrax lethal toxin (LT), a virulence factor secreted by Bacillus anthracis, is selectively toxic to human melanomas with the BRAF V600E activating mutation because of its proteolytic activities toward the mitogen-activated protein kinase kinases (MEKs).
Eleven of 18 melanoma cell lines were sensitive to anthrax lethal toxin (IC(50) < 400 pmol/L) and 10 of these 11 sensitive cell lines carried the V599E BRAF mutation.