Identification of a ferroptosis-related gene signature for predicting the prognosis of cholangiocarcinoma

Cholangiocarcinoma (CCA) is a highly intractable malignancy with poor prognosis. Ferroptosis, a newly explored type of programmed cell death, plays a critical role in the initiation and progression of a tumor. Herein, we aimed to identify a ferroptosis-related risk model to evaluate the prognosis of CCA. Differentially expressed genes (DEGs) were retrieved from three GEO cohorts. Univariate and LASSO analysis were employed to build a ferroptosis-related gene signature. Next, the predictive value was assessed in a training and a validation cohort. Metascape Online analysis, ESTIMATE and CIBERSORT algorithms, and ssGSEA were employed to perform the functional analysis between different risk groups. Finally, the expression of prognostic genes was validated with RT-qPCR. We identified 51 differentially expressed ferroptosis genes and established the prognostic signature containing five ferroptosis-related genes. The K-M curves and the ROC curves revealed a favorable predictive efficacy of the prognostic signature. Functional enrichment analysis indicated that immune-related responses were greatly enriched between different risk groups. Five prognostic genes were also differentially expressed in CCA cell lines. We developed a novel ferroptosis-related gene signature for CCA with high predictive accuracy. The analysis of the immune infiltration status may provide a potential therapeutic alternative to CCA.