Increase of transferrin binding induced by an alkyl-lysophospholipid in breast cancer cells.

The effect of ET-18-OCH3 on transferrin (Tf) binding in human breast cancer cell lines, MCF-7, ZR-75-1 and BT-20, and mouse fibroblast, Balb/c 3T3, was investigated. Pretreatment with 3-25 micrograms/ml ET-18-OCH3 increased the Tf binding at 37 degrees C and 4 degrees C in all cell lines tested. In MCF-7, both the affinity and the number of Tf binding sites were increased by ET-18-OCH3. These observations are of interest with respect to the action of ET-18-OCH3 on cell surface receptors.