NUPR1 Promotes Radioresistance in Colorectal Cancer Cells by Inhibiting Ferroptosis.

Radioresistance is a major clinical challenge and the underlying mechanism has not been thoroughly elucidated. In this study, a radioresistant (RR) cell line is established to explore the transcriptomic signatures of radioresistance in colorectal cancer (CRC). KEGG enriched pathway analysis demonstrated that ferroptosis is inactivated in RR cells. Further detection confirmed that radiotherapy can promote ferroptosis, and ferroptosis inactivation is one of the hallmarks of radioresistance in CRC. What's more, induction of ferroptosis can restore the radiosensitivity of CRC cells. Then, we performed RNA sequencing to compare gene expression between parental and RR cells, and cells pretreated with or without RSL3. Via high-throughput screening, NUPR1 was identified as a potential candidate for ferroptosis-mediated radioresistance in CRC. CRC cells can acquire radiation resistance by NUPR1-mediated ferroptosis suppression in the NUPR1-overexpressing cell line. More importantly, ZZW-115, an NUPR1 inhibitor, can sensitise RR cells to radiotherapy. Overall, our findings identify ferroptosis inactivation linked with resistance to radiotherapy. Besides, NUPR1 can promote radiation resistance by inhibiting ferroptosis, and targeting NUPR1 may be a potential strategy to relieve radioresistance associated with ferroptosis in CRC.