FGF6 inhibits oral squamous cell carcinoma progression by regulating PI3K/AKT and MAPK pathways

To explore diagnostic and prognostic biomarkers in the progression of oral squamous cell carcinoma (OSCC) and to reveal their regulatory mechanisms in key pathways. A RayBiotech protein chip was used to screen differentially expressed serum proteins in OSCC, oral leukoplakia (OLK), and healthy participants. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were used to determine the pathways enriched by characteristic differential proteins. Immunohistochemical analysis and western blotting were used to verify the expression of characteristic differential proteins and key regulatory factors in human tissues and in a nude mouse model. Fibroblast growth factor 6 (FGF6) was identified as a key differential protein and was weakly expressed in OSCC tissues. The mitogen-activated protein kinases (MAPK) and PI3K-AKT pathways were identified as key signaling pathways. The results showed that pERK, Cyclin D1, pAKT, and BCL2 were highly expressed in OSCC, Caspase9 was lowly expressed in OSCC. With an increase in FGF6 expression in nude mice, the expression of FGFR4, pERK, Cyclin D1, pAKT, BCL2, GPX4, and ACSL4 increased, and the expression of Caspase9 decreased. FGF6 may change the expression of apoptosis-related proteins and proliferation factors by binding to FGFR4 in the PI3K-AKT/MAPK pathway and may inhibit the ferroptosis of OSCC, thereby possibly participating in the process of inhibiting OSCC.