Rosenthal K L, Tompkins W A, Rawls W E
Cancer Res. 1980 Dec;40(12):4744-50.
Factors affecting the expression of carcinoembryonic antigen (CEA) at the surface of in vitro human colon carcinoma cells were determined using 125I-labeled antibodies. Binding of specific anti-CEA antibodies resulted in polar redistribution of CEA, followed by endocytosis of most of the CEA-anti-CEA complexes. These processes were temperature and energy dependent. CEA removed from the tumor cell surface by antibody was totally replaced within 6 hr at 37 degrees, and the reexpression of CEA required protein synthesis. Examination of clonally derived subpopulations of various strains of human colon cancer cells indicated that control over the level of cell surface CEA expressed was genetically stable in vitro. CEA expression was enhanced in a low-CEA-producing strain by incorporating theophylline in the culture medium, and the inclusions of bromodeoxyuridine enhanced the expression of a high-CEA-producing strain. The kinetics of enhancement of CEA expression by these two drugs differed. These findings suggest that CEA expression may be controlled by more than a single gene function.
利用¹²⁵I标记抗体确定了影响体外培养的人结肠癌细胞表面癌胚抗原（CEA）表达的因素。特异性抗CEA抗体的结合导致CEA极性重新分布，随后大部分CEA-抗CEA复合物被内吞。这些过程依赖于温度和能量。在37℃下，抗体从肿瘤细胞表面清除的CEA在6小时内完全被替代，并且CEA的重新表达需要蛋白质合成。对各种人结肠癌细胞系的克隆衍生亚群的检测表明，体外对细胞表面CEA表达水平的控制在遗传上是稳定的。通过在培养基中加入茶碱，低CEA产生株的CEA表达增强，而溴脱氧尿苷的加入增强了高CEA产生株的表达。这两种药物增强CEA表达的动力学不同。这些发现表明，CEA的表达可能受多个基因功能的控制。
