Unaltered mRNA Levels of EGFR and PIK3CA in Head and Neck Squamous Cell Carcinoma

Background: Since its identification, the Epidermal Growth Factor Receptor(EGFR) signaling pathway through PIK3CA has been known to be involved in thepathogenesis of several solid tumors, especially Head and Neck Squamous Cell Car-cinoma (HNSCC). Impaired signal transduction through EGFR-PIK3CA may giverise to oncogenic processes because of its key role in the regulation of major cellularfunctions. Several oncogenic mechanisms mediated by unregulated EGFR signalingpathways have been suggested by previous studies including mutations in genes en-coding EGFR and PIK3CA and increased ligands of EGFR. Here, we aimed to com-pare the total gene expression of EGFR and PIK3CA at the mRNA level betweenHNSCC tissues and normal squamous cell tissues. Methods: In this pilot study, we examined 31 samples of tumor-infected squamouscell tissues as well as 31 samples of healthy tissues around the tumor as controls forthe expression of EGFR and PIK3CA genes using quantitative polymerase chain re-actions (Q-PCR).Results: both EGFR and PIK3CA mRNA levels were slightly altered in HNSCC tis-sues compared with the control group (3% decrease and 9% increase, respectively),but these differences were not statistically significant. Conclusion: our results indicate that total EGRF and PIK3CA expression at themRNA level is not altered in Head and Neck Squamous Cell Carcinomas comparedwith that of normal squamous cell tissues.