Prognostic risk modeling based on integrated multi-omics analysis identifies CRY2 as a key regulator in tumor immunity and patient survival in colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) exhibits substantial metabolic heterogeneity. This study developed a robust prognostic signature integrating ferroptosis- and lipid metabolism-related genes to investigate the role of CRY2 in CRC progression. METHODS: Transcriptomic and clinical data from the TCGA-COAD and GSE39582 cohorts were analyzed. Weighted gene co-expression network analysis (WGCNA) was performed to identify disease-associated gene modules. A machine learning framework was subsequently applied to construct and optimize the prognostic model, with the combination of forward stepwise Cox regression (StepCox) and Random Survival Forest demonstrating the best predictive performance. The tumor immune microenvironment was characterized using CIBERSORT and TIDE. The biological function of CRY2 was validated through siRNA-mediated knockdown, functional assays, and a murine xenograft model. RESULTS: The ferroptosis- and lipid metabolism-related RiskScore was identified as an independent predictor of overall survival (HR > 1.1, p < 0.001). Patients in the high-risk group showed poorer overall survival and an immunosuppressive tumor microenvironment (TME) characterized by increased regulatory T cells (Tregs) and Th2 cells, reduced CD4+ T-cell infiltration, and higher TIDE scores, suggesting immunotherapy resistance. Among the signature genes, CRY2 was identified as a key regulator associated with CRC progression. In vitro, CRY2 knockdown inhibited CRC cell proliferation and migration while inducing G1-phase cell-cycle arrest. In vivo, silencing CRY2 significantly suppressed xenograft tumor growth and reduced Ki-67 expression. CONCLUSION: This study developed and validated a ferroptosis- and lipid metabolism-related prognostic signature that accurately predicts survival outcomes and immune characteristics in CRC. Furthermore, CRY2 was identified as a critical regulator of tumor growth.