Anti-HER2 phototoxin based on flavoprotein miniSOG causes the oxidative stress and necrosis of HER2-positive cancer cells

Abstract

Development and functional characterization of novel, high-affinity protein compounds able to selectively kill human cancer cells is an urgent task of modern biomedical research. In this work, we studied the cytotoxicity of a recombinant phototoxic protein DARPin-miniSOG against the HER2-positive human breast adenocarcinoma cells. It was found that targeted phototoxin DARPin-miniSOG interacts specifically with HER2 receptor and causes the light-induced death of HER2-positive cells by the mechanism of necrosis. Irradiation of the cells in the presence of ascorbic acid eliminates the light-induced cytotoxicity of DARPin-miniSOG, which proves the prooxidant mechanism of phototoxin action.