Oustry P, Estival A, Pradayrol L, Vaysse N, Clémente F
INSERM U.151, CHU Rangueil, Toulouse, France.
Int J Pancreatol. 1990 Mar;6(2):119-28. doi: 10.1007/BF02933046.
The existence of different classes of EGF receptors in human pancreatic cancer cells has yet not been determined. EGF binding to two cancer cell lines (CAPAN-1 and MIA PaCa-2) was studied. Two classes of EGF binding sites were characterized. The first class of EGF binding sites demonstrated a high affinity and low capacity for EGF, with a Kd of 0.25 +/- 0.11 nM, close to the concentration of EGF suggested to be present in human pancreatic juice. The second class of EGF binding sites had a lower affinity and a higher capacity for EGF, with Kd of 1.78 +/- 0.61 nM. The total number of EGF binding sites was about 40,000/cell. Treatment of the cells with a phorbol ester, TPA, caused a complete loss of the high affinity binding sites and also caused a decrease in the concentration of the lower affinity binding sites present on the cells. Interestingly, with the increasing age of the cells, the concentration of both the high and low affinity EGF binding sites was significantly decreased. In the presence or absence of fetal calf serum, EGF, at concentrations higher than 1.10(-10)M, exerted a dose-dependent mitogenic effect on the growth of the pancreatic cancer cells in culture. These data demonstrate the existence of two classes of binding sites for EGF on some human pancreatic cancer cells and a possible role of EGF in the growth of pancreatic tumors.
人类胰腺癌细胞中不同类别的表皮生长因子（EGF）受体的存在情况尚未确定。对EGF与两种癌细胞系（CAPAN-1和MIA PaCa-2）的结合进行了研究。鉴定出两类EGF结合位点。第一类EGF结合位点对EGF表现出高亲和力和低容量，解离常数（Kd）为0.25±0.11 nM，接近人胰液中推测存在的EGF浓度。第二类EGF结合位点对EGF的亲和力较低且容量较高，Kd为1.78±0.61 nM。EGF结合位点的总数约为40,000个/细胞。用佛波酯TPA处理细胞会导致高亲和力结合位点完全丧失，同时也会使细胞上存在的低亲和力结合位点浓度降低。有趣的是，随着细胞年龄的增加，高亲和力和低亲和力EGF结合位点的浓度均显著降低。在有或没有胎牛血清的情况下，浓度高于1.10（-10）M的EGF对培养中的胰腺癌细胞生长具有剂量依赖性的促有丝分裂作用。这些数据证明了某些人类胰腺癌细胞上存在两类EGF结合位点以及EGF在胰腺肿瘤生长中的可能作用。
