Correlation between EGF receptor expression and peplomycin cytotoxicity in squamous cell carcinoma cell lines

The relationship between sensitivity to anti-cancer agents and EGF receptor expression on squamous cell carcinoma (SCC) cells was investigated. The cytotoxicity of peplomycin (PEP) was correlated with the number of the EGF receptors expressed on the cancer cells, but no correlations were found between the cytotoxicity of adriamycin and cisplatin and EGF receptors. Addition of TNFalpha increased the number of EGF receptors in the SCC cell lines 1.5- to 2-fold. The cytotoxic effect of combined administration of PEP and TNFalpha was correlated with the number of EGF receptors, and produced a 2- to 5-fold increase in IC50 compared with administration of PEP alone. These observations suggest that EGF receptor expression is closely associated with the cytotoxic effect of PEP on SCC cells.