Integrated scRNA-Seq and functional profiling reveal CD52 as a driver of pancreatic ductal adenocarcinoma metastasis and immunosuppression.

Pancreatic ductal adenocarcinoma (PDAC) remains a highly aggressive malignancy driven by rapid metastasis and a profoundly immunosuppressive microenvironment. While the surface glycoprotein CD52 is a known immunoregulator, its precise role in solid tumors remains controversial, partly due to its broad expression across diverse cell populations and its compartment-specific functions within the tumor microenvironment. In this study, we utilized integrated single-cell RNA sequencing (scRNA-seq), functional assays, and compartment-specific clinical validation to elucidate the tumor-intrinsic functions of CD52 in PDAC. We identified a highly plastic, restricted subpopulation of CD52-high malignant epithelial cells that actively drives metastasis initiation by enhancing cellular invasive capacity. Concurrently, we demonstrated that tumor-derived CD52 orchestrated a multi-layered immunosuppressive network that attenuates CD8 + T cell cytotoxicity, facilitating early immune evasion. Furthermore, by systematically separating expression sources, our clinical validation established that tumor-derived CD52 is a prognostic indicator of poor patient survival. These findings characterize CD52 as a critical, tumor-intrinsic driver of PDAC progression, highlighting its value as a prognostic biomarker and a therapy target in combination with immune checkpoint blockade to overcome innate therapeutic resistance in PDAC.