Cetuximab inhibits cisplatin-induced activation of EGFR signaling in esophageal squamous cell carcinoma.

A malignant esophageal cancer, squamous cell carcinoma is one of the most prevalent cancers. Despite the use of present surgical techniques combined with various treatment modalities, the overall 5-year survival rate remains at 15-34%. Epidermal growth factor receptor (EGFR) is the most well studied receptor in various cancers and EGFR overexpression is detected in 40% of esophageal squamous cell carcinomas (ESCCs) and ESCC cell lines. To examine the EGFR antibody combination effect, we used treatment with cisplatin and cetuximab in ESCC cell lines, TE-4 and TE-8. Combination of cetuximab and cisplatin resulted in a growth inhibition only in the EGFR overexpressed TE-8 cell line. Furthermore, we confirmed that cisplatin-induced EGFR activation was inhibited by cetuximab in TE-8 but not in TE-4 cells. Our data suggest that cetuximab combined with cisplatin exerts antitumorigenic effects in vitro and in vivo via suppression of EGF signaling, which can be applied toward targeted ESCC treatments.