Abstract B125: Resolving PDAC cell subpopulations that seed metastatic recurrence

Approximately 40% of patients with pancreatic ductal adenocarcinoma (PDAC) receive no benefit from surgical resection and systemic chemotherapy and experience metastatic disease recurrence within 12 months. The extreme heterogeneity of the cells that populate PDAC tumors has been a significant impediment to identifying the cells that likely seed early recurrence. Previous studies show that metastatic spread is driven by specific cells with hybrid epithelial-mesenchymal characteristics, but despite the identification of numerous molecular features associated with epithelial, hybrid, and mesenchymal PDAC cancer cells, it has not been possible to specifically identify the cells that seed metastatic recurrence in human tissue. We have previously shown that PDAC cell glycan signatures are altered as a direct result of the metabolic and transcription changes that occur as PDAC cancer cells undergo EMT. Now we integrated the glycan signatures with known protein markers and morphological analyses using our pipeline for multiplexed immunofluorescence analysis to identify distinct subpopulations of epithelial, hybrid, and mesenchymal PDAC cells. In cell-level analyses of immunofluorescence images of 24 PDAC cell lines, these subpopulations revealed epithelial to hybrid to mesenchymal conversions along 3 distinct trajectories, which were defined by transcription factors and proteins previously associated with epithelial or mesenchymal states—TP53, TP63, GATA6, and MYC—and further distinguished by specific glycan signatures and protein markers of metabolism and cellular differentiation. The integrated transcription factor, glycan, and protein signatures identified the previously described classical and squamous PDAC subpopulations and defined a new signature for a fully mesenchymal subpopulation. The signatures differentiated between PDAC subpopulations in primary human tumors and in metastatic liver lesions and showed a patient-matched correspondence between the primary tumors and metastatic lesions in specific hybrid PDAC cells within distinct trajectories, potentially revealing the PDAC cells seeding metastatic recurrence. These results suggest that the development of mesenchymal and metastatic PDAC cells occurs through distinct, stepwise trajectories with divergent morphological, metabolic, molecular, and glycan-based signatures. These findings will/have the potential to inform the development of treatments that specifically target the PDAC cells that seed early metastatic recurrence. Citation Format: ChongFeng Gao, Zachary Klamer, Ali Moursy, Galen Hostetter, Paul M. Grandgenett, Peter Allen, Brian Haab. Resolving PDAC cell subpopulations that seed metastatic recurrence [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research—Emerging Science Driving Transformative Solutions; Boston, MA; 2025 Sep 28-Oct 1; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2025;85(18_Suppl_3): nr B125.