Watkins L F, Levine A E
Department of Pharmacology, Baylor College of Medicine, Houston, TX 77030.
Int J Cancer. 1991 Feb 1;47(3):455-60. doi: 10.1002/ijc.2910470325.
Antibodies to epidermal-growth-factor receptor (EGF) and transforming growth factor-alpha (TGF-alpha) were used to determine the role of endogenous TGF-alpha in the growth of 2 human colon-carcinoma cell lines. Both the GEO and HCT 116 colon-carcinoma cell lines secrete similar levels of TGF-alpha and have similar numbers of low-affinity binding sites for EGF. However, the HCT 116 cells lack the high-affinity EGF binding site present on the GEO cells. The anti-EGF receptor antibodies effectively blocked the binding of 125I-EGF to the GEO and HCT 116 cell lines. Growth of the GEO cell line was inhibited 50-80% by the anti-EGF receptor and anti-TGF-alpha antibodies. When the same antibodies, in sufficient amounts to block binding of TGF-alpha to the cells, were added to the HCT 116 cell line, no effect on growth was seen. These results suggest that while the GEO cell line utilizes TGF-alpha in an autocrine manner, the TGF-alpha secreted by the HCT 116 cells apparently does not play a role in the growth of these cells.
利用抗表皮生长因子受体（EGF）抗体和抗转化生长因子-α（TGF-α）抗体来确定内源性TGF-α在两种人结肠癌细胞系生长中的作用。GEO和HCT 116结肠癌细胞系分泌相似水平的TGF-α，并且具有相似数量的EGF低亲和力结合位点。然而，HCT 116细胞缺乏GEO细胞上存在的高亲和力EGF结合位点。抗EGF受体抗体有效地阻断了125I-EGF与GEO和HCT 116细胞系的结合。抗EGF受体抗体和抗TGF-α抗体使GEO细胞系的生长受到50%-80%的抑制。当将足以阻断TGF-α与细胞结合的相同抗体添加到HCT 116细胞系时，未观察到对生长的影响。这些结果表明，虽然GEO细胞系以自分泌方式利用TGF-α，但HCT 116细胞分泌的TGF-α显然在这些细胞的生长中不起作用。
