Superior Early Diagnostic Biomarkers for Pancreatic Cancer: A Proliferation-Immune Co-Regulation Six-Gene Module and MIF-CD44 Axis

Background: Pancreatic cancer is one of the most aggressive malignancies worldwide, characterized by challenges in early detection, limited therapeutic options, and extremely poor prognosis. Currently, highly sensitive diagnostic biomarkers are lacking, and the regulatory interplay between tumor proliferation drivers and the immunosuppressive microenvironment remains inadequately understood.
Methods: Grounded in a novel "proliferation-immune co-regulation" hypothesis, this study integrated multi-omics data from GEO and TCGA. Key feature genes were identified through differential expression analysis, Weighted Gene Co-expression Network Analysis, Protein-Protein Interaction hub gene screening, and rigorous cross-validation using three complementary machine learning algorithms: Least Absolute Shrinkage and Selection Operator, Support Vector Machine-Recursive Feature Elimination, and Random Forest. Multi-tiered computational approaches—including copy number variation analysis, single-cell transcriptomics, immune infiltration assessment, GWAS colocalization analysis, competitive endogenous RNA/transcription facto regulatory network construction, and drug screening—were employed to comprehensively elucidate their biological roles and clinical significance.
Results: We identified, for the first time, a "proliferation execution module" comprising six genes (GAPDH, ANLN, ECT2, TTK, CDCA2, and E2F7). This module was significantly overexpressed in pancreatic cancer tissues, demonstrating superior diagnostic performance (individual gene AUC: 0.731–0.828; combined model AUC: 0.902) compared to the conventional biomarker CA19-9. The resulting Nomogram model exhibited excellent discriminatory power and clinical utility. The module primarily regulates cell cycle and mitotic processes, with its overexpression strongly associated with immunosuppressive features, including CD8⁺ T cell depletion and M0 macrophage enrichment. Single-cell analysis further revealed distinct expression patterns in tumor epithelial cells and macrophages, and for the first time implicated SPP1-CD44 as a potential key immune regulatory axis. GWAS colocalization and multi-layered regulatory networks provided additional evidence for its genetic basis and mechanistic complexity.
Conclusion: This study systematically identifies a six-gene biomarker panel with substantial diagnostic value and, for the first time, proposes and validates a novel "proliferation-immune co-regulation" framework. This framework uncovers a dual-track synergistic mechanism whereby a downstream proliferation execution module drives autonomous tumor proliferation while actively shaping an immunosuppressive microenvironment, offering new molecular targets and a theoretical foundation for early diagnosis, prognostic evaluation, and combined therapeutic strategies in pancreatic cancer.