IRF1 is a tumor suppressor gene in
colon cancer. This study aimed to explore the potential regulation of IRF1 on the ferroptosis of
colon cancer and the mechanisms underlying its regulation of GPX4 transcription. IRF1 interacting
transcription factors regulating GPX4 transcription were predicted and validated. The role of the IRF1/SPI1-GPX4 axis on the ferroptosis of
colon cancer cells was explored. Results showed that IRF1 overexpression reduced GPX4 transcription, increased
reactive oxygen species (ROS) and
lipid ROS accumulation, and enhanced
erastin-induced
colon cancer cell growth in vitro and in vivo. SPI1 could directly bind to the GPX4 promoter (-414 to -409) and activate its transcription. IRF1 could bind to SPI1 and suppress its transcriptional activating effects on GPX4 expression. SPI1 overexpression reduced ROS and
lipid ROS accumulation and increased
colon cancer cell viability and colony formation upon
erastin induction. These trends were reversed by IRF1 overexpression. In conclusion, this study revealed a novel oncogenic mechanism of SPI1 by reducing
erastin-induced ferroptosis in
colon cancer. IRF1 interacts with SPI1 and suppresses its transcriptional activating effect on GPX4 expression. Through this mechanism, IRF1 can enhance
erastin-induced ferroptosis of
colon cancer. The IRF1/SPI1-GPX4 axis might play a crucial role in modulating ferroptosis in
colon cancer and might serve as a potential therapeutic target in the future.