O-GlcNAcylation with ubiquitination stabilizes METTL3, promoting HMGB1 degradation to inhibit ferroptosis and enhance gemcitabine resistance in pancreatic cancer

Background: Pancreatic cancer is highly lethal, and METTL3 plays a crucial role in m6A regulation. Although ferroptosis is important in cancer therapy, the regulatory mechanism of METTL3 in pancreatic cancer and its potential for regulating ferroptosis as a treatment remain unclear. Methods: The relationship between METTL3 and gemcitabine resistance and ferroptosis was investigated through in vitro and in vivo functional gain and loss experiments, while the target genes of METTL3 were identified using siRNA and pharmacological inhibitors to analyze the impact of O-GlcNAcylation on METTL3's stability and ubiquitination modification. Results: We found that O-GlcNAcylation interferes with ubiquitination-mediated regulation of METTL3 stability in pancreatic cancer cells, further clarifying its O-GlcNAcylation site and ubiquitination modification type. METTL3 regulates ferroptosis and Gemcitabine resistance by promoting HMGB1 degradation in a manner dependent on m6A-YTHDF2. Conclusion: Our study findings clearly demonstrate that METTL3 promotes pancreatic cancer cell proliferation and drug resistance to gemcitabine. This highlights the role of O-GlcNAcylation in stabilizing METTL3 expression and degrading HMGB1 through a m6A-YTHDF2-dependent mechanism, thereby inhibiting ferroptosis in pancreatic cancer cells. Furthermore, targeting HMGB1 while coordinating gemcitabine and RSL3 significantly suppresses pancreatic cancer tumor growth. These results provide valuable insights for the treatment of pancreatic cancer.