Edery M, Pang K, Larson L, Nandi S
Unité d'Endocrinologie Cellulaire et Moléculaire, INRA, Jouy-en-Josas, France.
Biomed Pharmacother. 1989;43(5):361-8. doi: 10.1016/0753-3322(89)90062-0.
An in vitro method of studying epidermal growth factor (EGF) receptors in mouse mammary epithelial cells in serum-free collagen gel culture has been developed. Binding of EGF averaged 108 +/- 19 fmol/mg DNA in cells isolated from freshly dissociated virgin mammary tissue. Initial binding values were maintained in cells cultured in the presence of 0.1 ng/ml EGF, but decreased in either 0 ng/ml or 10 ng/ml EGF. Addition of either chloroquine (100 microM) or ammonium chloride (10 mM) to the culture medium increased receptor levels 10-fold. Cycloheximide (0.1 microgram/ml), ouabain (3 mM), and actinomycin D (5 x 10(-2) micrograms/ml) each decreased receptor levels, in some cases by as much as 80%. Both methylamine (10 mM) and dinitrophenol (0.1 mM) had no significant effect. These studies suggest that the net level of EGF receptors in these target cells is the result of an equilibrium between synthesis and degradation. The difference between the effects of the compounds tested on either receptor degradation or synthesis in comparison to cell growth, may be indicative that receptor degradation is not linked to cell proliferation.
已开发出一种在无血清胶原凝胶培养中研究小鼠乳腺上皮细胞表皮生长因子（EGF）受体的体外方法。从新鲜解离的处女乳腺组织中分离的细胞中，EGF的结合量平均为108±19 fmol/mg DNA。在含有0.1 ng/ml EGF的条件下培养的细胞中，初始结合值得以维持，但在0 ng/ml或10 ng/ml EGF中则下降。向培养基中添加氯喹（100 microM）或氯化铵（10 mM）可使受体水平提高10倍。放线菌酮（0.1微克/毫升）、哇巴因（3 mM）和放线菌素D（5×10⁻²微克/毫升）均降低了受体水平，在某些情况下降低多达80%。甲胺（10 mM）和二硝基苯酚（0.1 mM）均无显著影响。这些研究表明，这些靶细胞中EGF受体的净水平是合成与降解之间平衡的结果。与细胞生长相比，所测试化合物对受体降解或合成的影响差异可能表明受体降解与细胞增殖无关。
