Lubrano C, Petrangeli E, Catizone A, Santonati A, Concolino G, Rombolá N, Frati L, Di Silverio F, Sciarra F
Clinica Medica V, University of Rome, La Sapienza, Italy.
J Steroid Biochem. 1989;34(1-6):499-504. doi: 10.1016/0022-4731(89)90134-9.
The receptor for epidermal growth factor (EGF-R) was characterized on membrane fractions from human benign prostatic hyperplasia (BPH). Specific binding of [125I]EGF reached equilibrium after 40 min at 25 degrees C and was stable for up to 120 min. Saturation analysis of EGF-R, performed by incubating the membranes with 0.0156-15 nM [125I]EGF in the presence and in the absence of 100-fold excess of cold EGF for 60 min, revealed the presence of two classes of binding sites with high and low affinities (Kd = 0.35 +/- 0.23 and 9.60 +/- 2.87 nM respectively). Competition experiments revealed that FSH, insulin and calcitonin did not compete with [125I]EGF. The simultaneous determination of EGF-R and that of estradiol (ER), progesterone (PR) and androgen receptors (AR) was performed using the same buffer to homogenate the tissues and to obtain cellular membranes. The steroid receptors (SR) were determined by means of the dextran-coated charcoal method. There was a significant negative correlation between nuclear SR and binding capacity of EGF-R. The presence of specific and high affinity binding sites for EGF and the modulation of the level of these sites by steroid receptors suggest a possible role of EGF in prostatic hyperplasia.
对来自人良性前列腺增生（BPH）的膜组分上的表皮生长因子受体（EGF-R）进行了表征。[125I]EGF的特异性结合在25℃下40分钟后达到平衡，并在长达120分钟内保持稳定。通过在存在和不存在100倍过量冷EGF的情况下，用0.0156 - 15 nM [125I]EGF孵育膜60分钟来进行EGF-R的饱和分析，结果显示存在两类具有高亲和力和低亲和力的结合位点（Kd分别为0.35±0.23和9.60±2.87 nM）。竞争实验表明，促卵泡激素（FSH）、胰岛素和降钙素不与[125I]EGF竞争。使用相同的缓冲液匀浆组织并获得细胞膜，同时测定EGF-R以及雌二醇（ER）、孕酮（PR）和雄激素受体（AR）。通过葡聚糖包被活性炭法测定类固醇受体（SR）。核SR与EGF-R的结合能力之间存在显著的负相关。EGF特异性高亲和力结合位点的存在以及类固醇受体对这些位点水平的调节表明EGF在前列腺增生中可能发挥作用。
