EGFR in melanoma: clinical significance and potential therapeutic target

Abstract

The role of epidermal growth factor receptor (EGFR) has been established in a range of neoplasms. In melanoma, data on EGFR protein expression are conflicting. Fluorescence in situ hybridization (FISH) analysis for EGFR gene expression in melanoma showed EGFR gene amplification to be linked with worse prognosis. Cetuximab has been shown to suppress the formation of metastasis in mice. EGFR protein expression and gene copy number status were evaluated by means of immunohistochemistry and FISH in melanoma samples of patients with known clinicopathological data. Associations between EGFR expression and prognostic parameters were investigated. The effect of different cetuximab concentrations on the BLM melanoma cell line was evaluated by means of methyl tetrazolium (MTT), sulforhodamine B (SRB) and Matrigel invasion assays. EGFR protein expression was more frequently observed in patients with a positive sentinel lymph node. However, EGFR immunostaining has no predictive value. The presence of EGFR polysomy was associated with thicker tumors. Treatment of the BLM melanoma cell line with different concentrations of cetuximab reduced the invasive capacity of the cells, but did not alter cell viability or growth. EGFR appears to be involved in progression and metastasis of a subset of melanomas. Targeting EGFR could therefore represent a therapeutic option for these melanomas.