Abstract
INTRODUCTION: Pancreatic ductal adenocarcinoma (PDAC) is characterised by a pronounced desmoplastic reaction, predominantly composed of cancer-associated fibroblasts (CAFs), including myofibroblastic CAFs (myCAFs). METHODS: We performed a single-cell assay for transposase-accessible chromatin with high-throughput sequencing (scATAC-seq) and single-cell RNA sequencing (scRNA-seq) on pancreas tissues from KPC mice (LSL-Kras(G12D/+); LSL-Trp53(R172H/+); Pdx-1-Cre) to characterise myCAF heterogeneity. A transgelin (Tagln) knockout orthotopic mouse model was used to determine the functional role of Tagln. RESULTS: Epigenetic profiling uncovered heterogeneity within the myCAF population, revealing distinct subclusters characterised by specific transcription factor (TF) motifs, such as Srf, Cebpb, Prrx1, and Smad4. We identified three transcriptionally distinct myCAF subtypes, each enriched for unique TF-associated signalling pathways. Among the identified myCAF subtypes, Tagln emerged as a potential functional driver. Tagln knockout mice exhibited significantly reduced PDAC tumour burden compared to wild-type. Analysis of TCGA revealed that high TAGLN expression in PDAC samples was associated with poor survival. CONCLUSIONS: Our findings highlight the functional heterogeneity of myCAFs and identify TAGLN-expressing myCAFs as critical mediators of tumour progression, providing evidence that targeting stromal TAGLN may represent a promising therapeutic strategy for PDAC.