Construction of anti-tumor immune gene signature for HNSCC and identification of 4'-Hydroxywogonin as a potential immunotherapy combination drug

Background: Head and neck squamous cell carcinoma (HNSCC) is an aggressive and heterogeneous malignancy, presenting challenges in accurately forecasting prognosis and immunotherapy response. This study endeavors to develop a robust gene signature to augment the prognostic prediction of HNSCC, and simultaneously uncover potential immunotherapy combination drug.

Methods: Transcriptome data from clinical HNSCC patients were analyzed using LASSO regression algorithm to construct a gene signature, followed by survival curve and ROC curve analyses, immune correlation analysis, and nomogram building. Furthermore, a comprehensive virtual screening of approximately 30,000 molecules was carried out based on the key target of signature. Finally, the potential immunotherapy combination drug was identified by molecular docking, CCK-8 assay, RT-qPCR assay, and molecular dynamics simulation.

Results: An anti-tumor immune gene signature (ATIGS) comprising 14 genes was established, which had promising potential in predicting the prognosis of HNSCC patients and could serve as an independent prognostic factor. Notably, ATIGS demonstrated a significant correlation with the infiltration level of several immune cells in the tumor immune microenvironment. It also had a good performance in predicting the response to immunotherapy. Further, protein-protein interaction (PPI) network analysis identified ZAP70 as a key target of ATIGS. Virtual screening of ~ 30,000 compounds found Puerol A, 4'-Hydroxywogonin, and Cirsimaritin as candidates, with 4'-Hydroxywogonin showing the strongest inhibition of CAL-27 and SCC7 cells. It also upregulated the expression levels of immune-related genes ZAP70 and LAT in CAL-27 cells, hinting at anti-tumor effect via immune pathway regulation. Molecular dynamics simulation showed stable binding of 4'-Hydroxywogonin to ZAP70 through hydrogen bonds and hydrophobic interactions, involving residues ALA417, GLU295, and LYS369.

Conclusions: This study successfully constructed a robust gene signature ATIGS, as well as identified a potential immunotherapy combination drug 4'-Hydroxywogonin. The ATIGS could effectively predict the prognosis and immunotherapy response of HNSCC patients, which may contribute towards enriching the immunotherapy-responsive population and enhancing the clinical efficacy of immunotherapy. Meanwhile, 4'-Hydroxywogonin may provide a promising clinical treatment strategy.