HPD is a copper-binding protein that interacts with DLAT to promote colorectal cancer cuproptosis under copper stress.

Copper is an essential trace element involved in various physiological processes. However, excessive copper levels in cells trigger cellular toxicity and "cuproptosis". Nevertheless, its role and the underlying mechanisms of cuproptosis in colorectal cancer (CRC) therapies remain largely unexplored. Unexpectedly, we find that copper triggers the translocation of a copper-binding protein, 4-hydroxyphenylpyruvate dioxygenase (HPD), into mitochondria via the TOMM40-TIM23 complex, in cooperation with HSP70 and HSP90. Upon arrival at the mitochondria, HPD interacts with dihydrolipoamide S-acetyltransferase (DLAT), thereby inducing cuproptosis. Furthermore, we identify Dacomitinib as an HPD-targeting cuproptosis inducer, which triggers CRC cuproptosis by enhancing the interaction between HPD and DLAT. Consequently, the combination of Dacomitinib and copper ionophores synergistically alleviates CRC tumorigenesis both in vitro and in vivo. In summary, our findings reveal that HPD, as a copper-binding protein, facilitates cuproptosis in cancer cells through its moonlighting function. This mechanism represents a therapeutic target for enhancing cuproptosis.