Molecular biology and histopathological analysis of EGFR signaling pathway in head and neck squamous cell carcinoma

MEHMET GUNDUZ; MAHMOUD AL SHEIKH ALI; HITOSHI NAGATSUKA; ESRA GUNDUZ; SILVIA S. BORKOSKY; RYO TAMAMURA; NORIYUKI NAGAI

Sapporo

Congreso; The 49th Annual Meeting of Japanese Association for Oral Biology; 2007

Japanese Association for Oral Biology

In order to clarify the mutation status of EGFR pathway and to find potential targets for molecular therapy as well as markers for drug response, PCR, SSCP and direct sequencing were used to detect the mutation status of the hot spot regions of EGFR, Her2, Kras and B-Raf. In 79 HNSCC samples used in this study, no mutation in EGFR, ErbB2, K-Ras and B- Raf was detected. Although these genes are over-expressed in HNSCC, our data shows that mutations are not common and may not play a significant role for the activation of the EGFR pathway in Japanese HNSCC patients. Mutation status EGFR has been linked to a better response of TK inhibitors in lung cancer. The lack of mutations in the TK domain of EGFR and ErbB2 could give explanation for the limited response to TKls in HNSCC, yet these tumors could depend on gene or protein expression level of EGFR or other signaling pathways independent of EGFR or ErbB2. EGFR protein expression by IHC and gene copy number by FISH analysis are currently being investigated for identification of a possible treatment-response marker in HNSCC.