Rhaponticin inhibits the proliferation, migration, and invasion of head and neck squamous cell carcinoma (HNSCC) cells through modulation of the IL6/STAT3 signaling pathway

Background: Rhaponticin, a bioactive compound derived from rhubarb, has been demonstrated anti-tumor effects in various types of cancer. However, its impact on head and neck squamous cell carcinoma (HNSCC) remains unexplored. This study aims to investigate the specific molecular mechanisms by which Rhaponticin inhibits the invasion and metastasis of HNSCC cells. Method: The potential target genes that rhaponticin acts on in HNSCC were identified using online databases. The mechanisms by which rhaponticin influences the occurrence and progression of HNSCC were investigated through network pharmacology, molecular docking, bioinformatics analysis, and cellular experiments. Result: Using network pharmacology, we identified 40 hub genes from the collected gene set. Subsequently, by analyzing The Cancer Genome Atlas (TCGA) data with four machine learning algorithms, we identified IL-6 as a potential target associated with the occurrence and progression of head and neck squamous cell carcinoma (HNSCC). Based on the average expression level of IL-6, we classified the samples into high-expression and low-expression groups and conducted survival analysis. Our results indicated that IL-6 expression was significantly correlated with patient survival. Gene Set Enrichment Analysis (GSEA) revealed that Rhaponticin might influence HNSCC via the IL6/STAT3 signaling pathway. Using the CIBERSORT algorithm, we assessed the differences in infiltration levels of 22 immune cell types between the high and low IL-6 expression groups. Our findings suggest that multiple immune cells may be involved in the pathogenesis of HNSCC. Additionally, we analyzed single-cell RNA sequencing (scRNA-seq) data from the GEO database to compare IL6 expression levels in tumor and normal tissues and evaluated its prognostic impact using Receiver Operating Characteristic (ROC) curve analysis. Molecular docking studies demonstrated that Rhaponticin binds stably to IL6. In the experimental section, we used two HNSCC cell lines (CAL27 and SCC9) to investigate the effects of Rhaponticin. Our results showed that Rhaponticin effectively inhibited cell proliferation, invasion, and migration, and reduced the expression of proteins in the IL6/STAT3 signaling pathway. Conclusion: Rhaponticin shows promise in treating HNSCC by inhibiting the IL6/STAT3 signaling pathway.