Integrated analysis reveals survival-related genes promoting cholangiocarcinoma progression via G2/M cell cycle, with validation of cyclin B1 in tumor proliferation

Cholangiocarcinoma (CCA) progression involves dysregulated cell cycle control, but core regulatory networks and their roles in tumor heterogeneity remain elusive. We integrated bulk transcriptomics (TCGA-CHOL and GEO cohorts) and single-cell RNA-seq (GSE138709) to identify survival-related genes (SRGs) driving CCA. Through limma, WGCNA, and PPI analysis, we identified seven SRGs (CDK1, ASPM, CCNB1, KIF2C, TOP2A, BUB1, DLGAP5) enriched in G2/M-phase pathways. Single-cell analysis revealed specific SRG upregulation in malignant epithelial subpopulations (PHGR1-Epi/UBE2C-Epi), with pseudotime trajectories demonstrating dynamically increased SRG expression during dedifferentiation. Functional validation confirmed CCNB1 as a core regulator: siRNA knockdown in HuCCT1/RBE cells significantly suppressed proliferation and clonogenicity. This study is the first to define a G2/M-phase gene module promoting CCA progression and map its single-cell dynamics, highlighting CCNB1 as a therapeutic target. Our results reveal SRGs as a coordinated oncogenic network underlying tumor aggressiveness, providing mechanistic insights for future SRG-targeted therapies.