ALDH1L2 induces resistance to chemotherapy in small cell lung cancer by inhibiting ferroptosis

Small cell lung cancer (SCLC) is known for its rapid growth and early metastasis, and SCLC patients are highly susceptible to chemoresistance. Studies have shown that the combination of ferroptosis induction and TRX pathway inhibition can significantly inhibit SCLC tumor growth, but the molecular mechanisms underlying ferroptosis in SCLC are poorly understood. In this study, we explored the regulatory role of the ALDH1L2-related metabolic pathway in SCLC chemoresistance by machine learning. We found that ALDH1L2 expression is a poor prognostic factor for SCLC patients and that high ALDH1L2 expression can negatively regulate the level of cellular lipid peroxidation and inhibit ferroptosis, thereby promoting SCLC chemoresistance. Mechanistically, ALDH1L2 interacts with the TRX2-PRDX3 antioxidant network to reduce the levels of hyperoxidized PRDX3 and oxidized PRDX3 dimers in the plasma membrane under cisplatin-induced stress and decrease cellular susceptibility to ferroptosis, thus promoting SCLC chemoresistance. In addition, we found that thiostrepton, a PRDX3 inhibitor, can synergize with chemotherapy to suppress tumor growth in SCLC, suggesting that thiostrepton might be a promising new tool for overcoming SCLC chemoresistance.