Molecular Analysis of EGFR and PIK3CA Genetic Mutations in Iranian Patients with Head and Neck Squamous Cell Carcinoma ‎

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Background: Many studies have demonstrated that mutations in EGFR / PI3K / AKT signaling pathway causes a central effect on the development of many cancers, such as head and neck squamous cell carcinoma (HNSSC). Moreover, these mutations were considered to be a major factor in drug response and prognosis. Objectives: In this research, we aimed to identify mutations in exons 18-21 of the EGFR gene and exons 9 and 20 of the PIK3CA gene in patients affected with HNSCC. We also determined the frequency of these mutations in Iranian HNSCC patients. Materials and Methods: Reverse hybridization assay (Strip assay) was used to assess the possible mutations in exons 18-21 of the EGFR gene. Concurrently, the presence of point mutations in the exons 9, 20 of the PIK3CA gene was performed by direct Sanger sequencing of PCR products. Results: Our study revealed that Iranian HNSCC patients have T790M mutation (2%) in exon 20 of the EGFR gene as the only mutation contributing to the kinase domain of this gene. Our study also indicated that the frequency of mutations in exons 9 and 20 of the PIK3CA gene is 16%. Conclusion: In comparison with other populations, the identification of three novel mutations in the PIK3CA gene from 50 patients hypothesizes that Iranian HNSCC patients may have different frequencies of PIK3CA mutations that may affect HNSCC pathogenesis and drug response predictions. In the current study, a mutation frequency of EGFR is similar to previous studies