CPT1A-mediated MFF succinylation promotes stemness maintenance in ovarian cancer stem cells by enhancing mitochondria-associated membranes formation
Cancer stem cells (CSCs) are key players in cancer progression, immune evasion, drug resistance, and recurrence, particularly in ovarian cancer. Mitochondria-associated membranes (MAMs) are dynamic structures linking mitochondria and the endoplasmic reticulum, essential for cellular processes. Whether MAMs supports CSCs and the underlying mechanisms remain largely unknown. Here, we unveil that CPT1A is highly expressed in ovarian cancer stem cells (OCSCs) and is essential for stemness maintenance. CPT1A facilitates stemness maintenance by regulating lipid desaturation in ovarian cancer. Further studies confirmed that CPT1A enhances SREBP1 cleavage and nuclear translocation, thereby upregulating SCD1 expression and promoting lipid desaturation in OCSCs. Furthermore, MAMs are found to be critical for SREBP1 activation. Mechanistic studies have shown that CPT1A promotes mitochondrial fission factor (MFF) succinylation (succK-MFF) through its lysine succinyltransferase (LSTase) activity, with succK-MFF being crucial for MAMs formation and SREBP1 activation. Additionally, inhibiting the LSTase activity of CPT1A with Glyburide reduced OCSCs' stemness and enhanced cisplatin's anti-tumor effects against ovarian cancer both in vitro and in vivo. Together, our studies reveal the importance of CPT1A's LSTase activity in MAMs formation and OCSCs' stemness maintenance, providing potential targets and therapeutic strategies for ovarian cancer treatment. Overall design: To investigate the function of CPT1A in lipid metabolism, we established the SKOV3 cell line and knocked down the CPT1A target gene with shRNA.