文章基本信息

标题：Specific binding of phorbol ester tumor promoters
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作者：Paul E. Driedger ; Peter M. Blumberg
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1980
卷号：77
期号：1
页码：567-571
DOI：10.1073/pnas.77.1.567
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：[20-3H]Phorbol 12,13-dibutyrate bound to particulate preparations from chicken embryo fibroblasts in a specific, saturable, reversible fashion. Equilibrium binding occurred with a Kd of 25 nM; this value is very close to the 50% effective dose (ED50), 50 nM, previously determined for the biological response (induction of fibronectin loss) in growing chicken embryo fibroblasts. At saturation, 1.4 pmol of [20-3H]phorbol 12,13-dibutyrate was bound per mg of protein (approximately 7 x 104 molecules per cell). Binding was inhibited by phorbol 12-myristate 13-acetate (Ki = 2 nM), mezerein (Ki = 180 nM), phorbol 12,13-dibenzoate (Ki = 180 nM), phorbol 12,13-diacetate (Ki = 1.7 {micro}M), phorbol 12,13,20-triacetate (Ki = 39 {micro}M), and phorbol 13-acetate (Ki = 120 {micro}M). The measured Ki values are all within a factor of 3.5 of the ED50 values of these derivatives for inducing loss of fibronectin in intact cells. Binding was not inhibited by the inactive compounds phorbol (10 {micro}g/ml) and 4-phorbol 12,13-didecanoate (10 {micro}g/ml) or by the inflammatory but nonpromoting phorbol-related diterpene esters resiniferatoxin (100 ng/ml) and 12-deoxyphorbol 13-isobutyrate 20-acetate (100 ng/ml). These data suggest that biological responses to the phorbol esters in chicken embryo fibroblasts are mediated by this binding activity and that the binding activity corresponds to the phorbol ester target in mouse skin involved in tumor promotion. Binding was not inhibited by the nonphorbol promoters anthralin (1 {micro}M), phenol (1 mM), iodoacetic acid (1.7 {micro}M), and cantharidin (75 {micro}M), or by epidermal growth factor (100 ng/ml), dexamethasone acetate (2 {micro}M), retinoic acid (10 {micro}M), or prostaglandin E2 (1 {micro}M). These agents thus appear to act at a target distinct from that of the phorbol esters.
关键词：carcinogenesis ; receptors ; chicken embryo fibroblasts