SRF/SLC31A1 signaling promotes cuproptosis induced by celastrol in NSCLC

Faced with the highly malignant challenge of lung cancer, traditional chemotherapeutic agents, although predominantly inducing apoptosis, are severely limited in their therapeutic effect by the overexpression of anti-apoptotic proteins in lung cancer. Recently discovered copper-induced non-apoptotic cell death, known as cuproptosis, represents a novel mechanism for regulating cell death. Whether Celastrol (Cel), a potential anti-tumor drug, can counter non-small cell lung cancer (NSCLC) through inducing cuproptosis remains to be thoroughly investigated. This study demonstrates that the copper chelator tetrathiomolybdate (TTM) is more effective in rescuing Cel-induced NSCLC cell death compared to other inhibitors. RNA sequencing revealed that Cel significantly upregulates the copper transporter protein SLC31A1. In addition, Cel also promotes intracellular copper accumulation, reduces GSH levels, and exhibits features of cuproptosis, including loss of iron-sulfur cluster proteins (FDX1, SDHB, POLD1), increased HSP70, and DLAT oligomerization. Experiments also found that Cel significantly increases reactive oxygen species (ROS) levels, reduces mitochondrial membrane potential, and lowers ATP levels. It was predicted through online databases that SRF may be the transcription factor for SLC31A1, and this was validated through overexpression experiments. In vivo data demonstrated that Cel significantly inhibits tumor growth without damaging the heart, liver, or kidneys of mice. This study first reveals that celastrol disrupts intracellular copper homeostasis through the SRF/SLC31A1 pathway, promoting cuproptosis in NSCLC cells, providing support for Cel as a potential safe and effective chemotherapeutic agent.