Correlation between EGF receptor expression and peplomycin cytotoxicity insquamous cell carcinoma cell lines

The relationship between sensitivity to anti-cancer agents and ECF receptor expression on squamous cell carcinoma (SCC) cells was investigated. The cy totoxicity of peplomycin (PEP) was correlated with the number of the EGF re ceptors expressed on the cancer cells, but no correlations were found betwe en the cytotoxicity of adriamycin and cisplatin and EGF receptors. Addition of TNF alpha 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 T NF alpha was correlated with the number of EGF receptors, and produced a 2- to 5-foid increase in IC50 compared with administration of PEP alone. Thes e observations suggest that EGF receptor expression is closely associated w ith the cytotoxic effect of PEP on SCC cells.