ProteinPNet: Prototypical Part Networks for Concept Learning in Spatial Proteomics
Resolving the spatial heterogeneity of the tumor microenvironment (TME) is critical for precision oncology, yet existing methods struggle to learn biologically grounded, discriminative, and interpretable prototypes directly from spatial proteomics data. To address this, we propose an end-to-end learnable Prototype-Part Network that jointly integrates supervised contrastive learning, graph-structured modeling, and morphological analysis to automatically discover and interpretably model spatial functional modules within the TME. Evaluated on both synthetic benchmarks and real-world spatial proteomics data from non-small cell lung cancer, our method robustly identifies immune infiltration patterns and tissue modularity features highly concordant with histopathological subtypes. Notably, it achieves the first supervised prototype learning of spatial motifs in the TME—recurring, biologically meaningful spatial configurations of protein expression. This establishes a novel, mechanism-driven paradigm for discovering spatially resolved biomarkers with direct biological interpretability.