Construction and Clinical Validation of a Colorectal Cancer OPISV Prognostic Model Integrating EPHB2 and ZNF346: Potential Regulatory Role of the Axon Guidance Pathway.

IntroductionColorectal cancer (CRC) is a common malignancy characterized by high recurrence rates and frequent late-stage diagnoses, highlighting the need for reliable prognostic biomarkers. Despite the existence of several multi-gene prognostic models, these often fail to account for individual molecular heterogeneity and the influence of neuromodulatory pathways. The Axon Guidance pathway, a critical regulator of the nervous system, has been implicated in tumor progression; however, its prognostic significance in CRC remains largely unexplored.MethodTo address this gap, a novel prognostic index, the Optimal Prognostic Index of Survival Variables (OPISV), was developed. Using transcriptomic and clinical data from The Cancer Genome Atlas (TCGA) CRC cohort, survival-associated genes were first identified through Kaplan-Meier analysis, and differentially expressed genes were determined via the Wilcoxon rank-sum test. Key prognostic variables were rigorously selected through univariate Cox regression, least absolute shrinkage and selection operator (LASSO) regression, and stepwise multivariate Cox regression. The final OPISV model incorporated four variables: age, M stage, EPHB2, and ZNF346. Its predictive performance was robustly evaluated using time-dependent receiver operating characteristic (ROC) curves, Kaplan-Meier survival analysis, and calibration curves, with external validation in two independent Gene Expression Omnibus (GEO) datasets (GSE39582 and GSE17537). Protein expression levels of the target genes were further validated by Western blotting in CRC tissues and matched adjacent non-tumor tissues from our hospital.ResultThe OPISV model effectively stratified patients into high- and low-risk groups with significantly different overall survival (p < 0.001). Functional enrichment analysis revealed significant activation of the Axon Guidance pathway in the high-risk group. Unsupervised clustering of related genes confirmed the pathway's central role and highlighted distinct immune and mutational landscapes between subtypes. Western blotting analysis of clinical samples confirmed significant upregulation of EPHB2 and ZNF346 proteins in CRC tissues, highlighting their biological and clinical relevance.ConclusionThe OPISV model is a reliable and practical tool for predicting CRC prognosis and offers valuable mechanistic insights into the role of the Axon Guidance pathway in tumor progression.