Radiotherapy followed by metformin neoadjuvant therapy drives superior pancreatic cancer ferroptosis and augments anti-tumor immunity.

Although neoadjuvant therapy has achieved higher levels of resectability and improved the survival outcomes of pancreatic carcinoma patients, cancer cells' resistance to conventional cell death has limited its clinical efficiency. Thus, developing an optimal sequence of novel neoadjuvant therapy modalities to boost cancer cell death is urgently needed. The current work addresses this issue by developing a combination of radiotherapy with metformin as a novel neoadjuvant therapy and investigating its optimal sequencing treatment to boost cancer cell ferroptosis. Of the three treatment regimens investigated, the sequential treatment with RT followed by metformin (i.e. as opposed to metformin followed by RT, or simultaneous treatment with both RT and metformin) was most effective in eliciting ferroptosis in vitro and in animal models. Mechanically, RT followed by metformin is dependent on the inhibition of the AMPK-GOT1 axis, which further leads to the arrest of cancer cells in G1/S phase, and ultimately ferroptosis. Moreover, using a combination of patient samples and mouse models, RT followed by metformin enhanced the anti-tumor immune cells (IFNγ