Aberrant expression of TRIM26 suppresses ferroptosis through regulating GPX4 protein stability in colorectal cancer.

BACKGROUND: Ferroptosis is recognized as a critical regulator of tumor growth in colorectal cancer (CRC). The enzyme GPX4 plays a vital role in regulating ferroptosis by converting lipid hydroperoxides into non-toxic lipid alcohols, thus protecting cells from ferroptosis. However, the mechanisms by which GPX4 mediates ferroptosis in CRC remain largely unexplored.

METHODS AND RESULTS: A significant increase was observed in both mRNA and protein expression of TRIM26 in CRC tissues compared to healthy colon tissues. TRIM26 regulates the cell proliferation in both HT-26 and HCT116 cells. TRIM26 affects CRC cell proliferation in both apoptotic and ferroptotic independent manners. Ferroptosis inhibitors, ferrostatin-1 and liproxstatin-1, counteract the effects of TRIM26 knockdown, whereas ferroptosis inducers mitigate the effects of TRIM26 overexpression on ferroptosis in cancer cells. In vitro studies demonstrates that aberrant TRIM26 expression positively influences the stability of GPX4. TRIM26 directly interacts with GPX4 and catalyzes the ubiquitination of GPX4, which thus enhances GPX4 protein stability. Furthermore, rescue experiments indicate that the enhancement of ferroptosis caused by sh-TRIM26 is reversed following GPX4 overexpression.

CONCLUSIONS: Collectively, these findings underscore the significance of aberrant TRIM26 expression in disrupting ferroptosis through the regulation of GPX4 protein stability in CRC. This insight suggests a potential therapeutic strategy targeting TRIM26 to inhibit tumor growth in CRC.