This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Kosano, H. Articles by Takatani, O. Search for Related Content PubMed PubMed Citation Articles by Kosano, H. Articles by Takatani, O.

Inhibition by an Alkyl-Lysophospholipid of the Uptake of Epidermal Growth Factor in Human Breast Cancer Cell Lines in Relation to Epidermal Growth Factor Internalization

Third Department of Internal Medicine, National Defense Medical College, 3-2, Namiki, Tokorozawa, Saitama 359, Japan

The effects of 1-O-octadecyl-2-O-methyl-sn-glycerol-3-phosphocholine (ET-18-OCH₃), an alkyl-lysophospholipid derivative, on the binding and uptake of labeled epidermal growth factor (EGF) in hormone-dependent (MCF-7 and ZR-75-1) and hormone-independent (BT-20) breast cancer cell lines were investigated at 4°C and 37°C. The total (bound and intracellular) EGF associated with breast cancer cells tested were largely temperature dependent. By pretreatment of the cells with ET-18-OCH₃ (10 µg/ml) for 12 h, the EGF uptake at 37°C was greatly reduced in both MCF-7 and ZR-75-1 (ET-18-OCH₃-susceptible) but not in BT-20 (ET-18-OCH₃-resistant) cell lines. The ET-18-OCH₃ pretreatment slightly decreased the EGF uptake at 4°C in MCF-7 and ZR-75-1 and had little effect on that in BT-20. The EGF binding at 37°C was unaffected by ET-18-OCH₃ in MCF-7 and BT-20 and slightly decreased in ZR-75-1. The EGF binding at 4°C was not changed by ET-18-OCH₃ in all cell lines tested. These results suggest that labeled EGF is taken up by the cells in a temperature-dependent manner and ET-18-OCH₃ may inhibit this internalization process only in ET-18-OCH₃-sensitive human breast cancer cell lines. It is inferrable that the inhibition of the internalization process for EGF may be one of the modes of antitumoral action of ET-18-OCH₃.

¹ To whom requests for reprints should be addressed.

Received 11/10/88. Revised 3/ 3/89. Accepted 3/ 8/89.