TRAP1 ablation improves mitochondrial cristae and oxidative phosphorylation in pancreatic cancer stem cells

Aim: Cancer stem cells (CSCs) in pancreatic ductal adenocarcinoma (PDAC) display high metabolic plasticity, supporting tumor aggressiveness and therapeutic resistance. Here, we investigated the role of the mitochondrial chaperone TRAP1 in regulating mitochondrial architecture, metabolism, and adhesion in CSCs. Methods: We studied an in vitro model of CSCs using Panc1 cells and the corresponding stable TRAP1-knockout cells (TRAP1-KO). Molecular techniques used were quantitative polymerase chain reaction (qPCR), Western blot, transmission electron microscopy, and Seahorse technology. Results: CSCs showed increased TRAP1 expression after 2 weeks of culture, reflecting a preferential metabolic shift toward glycolysis. TRAP1 deletion impaired the ability of CSCs to form compact spheroids without altering canonical CSC traits, such as reduced proliferation, increased stem marker expression, and enhanced chemoresistance. We demonstrate that TRAP1 deletion increases CDH1, an effect that was reversed by succinate supplementation, indicating that the TRAP1-succinate-CDH1 axis controls adhesion-related properties. Ultrastructural analyses revealed profound mitochondrial remodeling in the absence of TRAP1: parental cells displayed enlarged, elongated mitochondria with wider cristae, whereas CSCs developed fragmented mitochondria with thinner cristae and tighter crista junctions. These alterations were closely associated with the differential regulation of mitochondrial fission factor (MFF). Functionally, loss of TRAP1 enhanced oxidative phosphorylation, leading to increased mitochondrial adenosine triphosphate (ATP) production, elevated maximal respiration, and reduced proton leak. Conclusion: Collectively, these findings identify TRAP1 as a critical regulator of mitochondrial organization, respiratory efficiency, and CDH1-mediated adhesion in PDAC CSCs, highlighting metabolic and structural vulnerabilities that may be exploited therapeutically to destabilize CSC homeostasis and enhance treatment response.