Prostaglandin synthesis by squamous carcinoma cells of head and neck, and its inhibition by non-steroidal anti-inflammatory drugs

The purpose of this study was to determine the nature and amounts of prostaglandins (PGs) produced by squamous carcinoma cells (SCC) and the sensitivity of these cells to non-steroidal anti-inflammatory drugs. SCC of four lines of the tongue and one line of facial epidermis of humans were incubated in phosphate buffer solution with ¹⁴C-arachidonic acid (AA). Radioactive metabolites in aqueous methanol were chromatographed on Sep-Pack CIS cartridges, separated and quantitated by means of TLC, autoradiography, and liquid scintillation counting. The results showed that cyclooxygenase products, PGs, were the major products formed by all cell lines, and PGE₂ was predominant among the PGs detected. Two radioactive bands corresponding to PGF_2α and three unseparated standards of PGA₂, 15-keto-PGE₂, and 13,14-dihydro-15-keto-PGE₂were detected in lesser amounts. Very small amounts of the lipoxygenase products 12-and 15-HETE were found. The concentrations of indomethacin, ibuprofen and aspirin required to inhibit 50% of PGE₂ synthesis (IC₅₀) by SCC lines were .008- .080, .080–6.4 and 32–88 μM, respectively.