Deamidated TPI is an efficacious target for cell-selective therapy in triple-negative breast cancer

Human TPI (HsTPI) is a central and essential glycolytic enzyme for energy supply and is overexpressed in cancer cells. Here, we investigated HsTPI as a potential target for inducing cell death in triple-hormone receptor-negative breast cancer, which is highly dependent on glycolysis, and therapies for its treatment are limited. We found endogenous accumulation of deamidated HsTPI in human breast cancer cells, which might be caused by the lower activity of the HsTPI-degrading caspase-1 in breast cancer cells. In silico and in vitro analyses of deamidated HsTPI demonstrated the efficacy of thiol-reactive drugs in blocking enzyme activity. The cancer cells were selectively programmed to undergo apoptosis with thiol-reactive drugs by inducing the production of methylglyoxal (MGO) and advanced glycation-end products (AGEs). In vivo in mice, the thiol-reactive drug effectively inhibited the growth of human tumors by targeting HsTPI as underlying mechanism. Our findings demonstrate deamidated HsTPI as a novel target to develop therapeutic strategies for treating cancers and other pathologies in which this post-translationally modified protein accumulates.