Matrix Stiffness-Sensitive LDHA Drives Autophagy of Pancreatic Ductal Adenocarcinoma via Lactate-Induced FOXO3 Expression and Lactylation

Pancreatic ductal adenocarcinoma (PDAC), a highly aggressive tumor within the digestive system, is characterized by the high stiffness of the extracellular matrix (ECM), which has fundamental influences on biological processes and malignant phenotypes of PDAC. Autophagy, as a key process of PDAC, significantly accelerates malignant progression and ultimately leads to adverse prognosis. Consequently, it is crucial to comprehend the underlying mechanisms of the interplay between matrix stiffness and PDAC autophagy. To serve the intent, Polyacrylamide (PA) hydrogels with adjustable stiffness were utilized to cultivate MIA PaCa-2 and PANC-1 cells. The outcomes established that high stiffness induced lactate production via the activation of lactate dehydrogenase A (LDHA), resulting in the upregulation of transcription factor FOXO3 and subsequent induction of autophagy. Interestingly, in vivo experiments, the MIA PaCa-2 cells educated by stiff PA hydrogels exhibited not only higher tumorigenicity, but also persistent phenotype maintenance and gene expression, which implied the potential epigenetic modulation of matrix stiffness. Through DeepKla analysis, Co-Immunoprecipitation (Co-IP) and Western Blot (WB), we identified that matrix stiffness drives FOXO3 lysine lactylation (Kla) modification by promoting LDHA-dependent lactate production, thereby sustaining the persistent activation of autophagy. In conclusion, we revealed the key role of matrix stiffness in lactate metabolism, lactylation modification and autophagy activation of PDAC, offering both foundational theory and potential therapeutic targets for precision medicine in PDAC.