Identification and validation of a Golgi apparatus related gene signature for prognosis prediction and immune microenvironment profiling in colorectal cancer

BACKGROUND: Colorectal cancer (CRC) is a leading cause of cancer mortality. The Golgi apparatus (GA) mediates protein glycosylation and secretion, and its dysfunction is implicated in cancer invasion and immune evasion [1]. The prognostic relevance of GA-related genes in CRC remains unclear. METHODS: Transcriptomic and clinical data from TCGA-COAD/READ and GSE39582 were analysed. A set of 1 686 GA-related genes from MSigDB was filtered by differential expression, and prognostic candidates were selected using univariate Cox, LASSO and random forest approaches to construct a multi-gene risk score. Functional enrichment, immune infiltration (ESTIMATE/CIBERSORT) and drug-sensitivity (oncoPredict) analyses were performed, and a nomogram combining the GA score with clinical covariates was built. RESULTS: Among 5580 differentially expressed genes, 434 were GA-related. A six-gene signature (PCSK5, RAB36, CD36, DPP7, KPNA2, HEPACAM2) stratified patients into high- and low-risk groups with significant survival differences and retained independent prognostic value after adjusting for age and stage. High-risk tumors showed enrichment of proteoglycan and G-protein-coupled receptor pathways, higher immune and stromal scores with abundant monocytes and macrophages but fewer dendritic and T cells, and were predicted to respond poorly to immune checkpoint blockade yet displayed increased sensitivity to the IGF-1R inhibitor BMS-754,807. CONCLUSIONS: GA related gene expression delineates CRC subtypes with distinct biology, immunity and therapeutic vulnerabilities. Integrating the GA derived signature with clinical factors may help refine risk stratification and generate hypotheses regarding glycosylation-/proteoglycan-related therapeutic vulnerability and IGF-1R inhibition.