Risk model-guided identification of MTDH expression as a marker for ferroptosis induction therapy in head and neck squamous cell carcinoma.

Head and neck squamous cell carcinoma (HNSCC) are a prevalent malignancy with high mortality and morbidity rates. Therefore, in this study, we aimed to develop a novel risk score model by using a DNA methylation signature associated with ferroptosis to enhance the prognosis prediction of HNSCC. The transcriptome, methylome, and clinical data of HNSCC patients were collected from The Cancer Genome Atlas (TCGA) database. Additionally, data from a methylation dataset in the Gene Expression Omnibus (GEO) database were used for validation. The ferroptosis score (FS) in each patient was calculated using the transcriptome data, and the single-sample gene set enrichment analysis (ssGSEA) was performed to assess ferroptosis activity. Furthermore, a series of biochemical experiments including CCK8, colony formation, wound healing, and ROS detection were carried out to evaluate the influence of MTDH on the malignancy of HNSCC. Our results revealed that the FS was associated with patient prognosis, as the patients with high FS had a poor prognosis. The receiver operating characteristic (ROC) curve established based on the ferroptosis-associated DNA methylation signature, demonstrated the excellent predictive power of FS for the 1-, 3-, and 5-year survival of HNSCC. Importantly, this predictive model was successfully validated in the GEO dataset. The nomogram also demonstrated excellent accuracy and reliability, as determined by the calibration curves and the decision curve analysis (DCA) plot. Interestingly, the risk score model was found to be correlated with immune cell infiltration and immunotherapy-related biomarkers, suggesting its potential in predicting the immunotherapy response in HNSCC treatment. Moreover, we found that the expression of two risk score model component genes, SETD1B and MTDH, was significantly different between tumor and the adjacent tissues in patients with LSCC, which was also significantly correlated with patient prognosis. Further experimental validation showed that the upregulated expression of MTDH significantly inhibited ferroptosis through regulating GPX4 expression and enhanced the cytotoxicity of ferroptosis inducers in HNSCC cells. In conclusion, we have developed a risk score model by using a ferroptosis-related DNA methylation signature, which can be used as an alternative tool to predict the prognosis of patients with HNSCC. SETD1B and MTDH were identified as the pivotal genes in this model and might play important role in the progression of HNSCC.