Cross-Cancer Profiling of Cadherin-1 Reveals Context-Dependent Epithelial-Mesenchymal Transition Decoupling, Immune Heterogeneity, and Prognostic Variability in Epithelial Cancers

BackgroundCDH1 (E-cadherin) is a key epithelial adhesion molecule traditionally associated with tumor suppression and epithelial-mesenchymal transition (EMT). However, its roles across cancers remain incompletely understood, particularly within multilayer regulatory contexts involving genomic, epigenetic, transcriptional, and immune mechanisms. MethodsCDH1 expression, survival associations, EMT-correlated gene profiles (VIM, SNAI1, ZEB1), immune infiltration patterns, immune checkpoint correlations (PDCD1, CD274, CTLA4), promoter methylation, and genomic alterations were assessed across five epithelial cancers, breast invasive carcinoma (BRCA), colon adenocarcinoma (COAD), lung adenocarcinoma (LUAD), ovarian cancer (OV), and stomach adenocarcinoma (STAD). Cross-platform validation was performed using TCGA/GDC datasets, GEPIA2, UALCAN, TIMER, KM Plotter, cBioPortal, and g:Profiler. ResultsCDH1 was overexpressed but showed variable prognostic significance; higher expression predicted better survival in COAD, LUAD and STAD, worse survival in BRCA and had no impact in OV. Classic inverse relationships between CDH1 and VIM or ZEB1 were evident only in STAD, and SNAI1 showed no consistent association. Immune infiltration patterns were tumor-specific, ranging from cytotoxic T-cell dominance in LUAD to macrophage-rich profiles in OV; immune checkpoint correlations were similarly context-dependent. Co-expressed genes were enriched for endomembrane transport rather than adhesion pathways. Promoter methylation patterns varied by cancer, whereas genomic alterations of CDH1 were rare. ConclusionsCDH1 does not function as a universal epithelial or EMT marker across epithelial cancers. Instead, its associations with EMT, immune contexture, methylation, and prognosis are context-dependent, supporting a model of CDH1 as a heterogeneous regulator of epithelial plasticity. These findings challenge single-function interpretations and support cancer-specific CDH1 evaluation in translational research.