Chakrabarty S, Miller C A, Brattain M G
Cancer Invest. 1986;4(1):5-14. doi: 10.3109/07357908609039822.
Molecular alterations of cellular proteins were assessed in three previously described subpopulations of human colon carcinoma cells that were originally isolated from a single human primary colon carcinoma. The subpopulations designated HCT 116b, HCT 116, and HCT 116a exhibited significant differences in their expression of several biological properties. Immunoautoradiographic analysis of membrane components, fractionated by SDS-PAGE and electrophoretically transferred onto nitrocellulose sheets, distinguished the most aggressive tumor cell subpopulation from the intermediate and least aggressive subpopulations. An elevated expression of antigens of molecular weight in the range of 116-120 kd, 92 kd, 55-66 kd, and 31 kd was found to be associated with the most aggressive subpopulation of HCT 116a cells. The binding pattern of RCA I and WGA lectins to membrane components, fractionated by SDS-PAGE and fixed on nitrocellulose, also distinguished the three subpopulations of cells. Elevated bindings of RCA I to 80-92 kd components of HCT 116b cells and elevated bindings of WGA to 120 kd components of HCT 116a cells distinguished the three subpopulations from one another. Analysis of cellular phosphoprotein profiles, following labeling of the cells with 32Pi in the presence of phosphate-free medium, further distinguished the most aggressive subpopulation from the intermediate and least aggressive subpopulations. High level of phosphorylation of 120 kd and 250 kd nuclear components, 30 and 90 kd cytosolic components, and low level of phosphorylation of lower molecular weight membrane components were found to be associated with the most aggressive subpopulation. It is concluded that differences in the expression of membrane antigens, differences in the glycosylation of membrane components, and the selective phosphorylation and/or dephosphorylation of cellular proteins exist in subpopulations of intratumoral colonic carcinoma cells with different biological properties. These biochemical alterations of cellular proteins may play an important role in the generation of phenotypic diversity and heterogeneity of malignant cells.
在先前描述的三个人类结肠癌细胞亚群中评估了细胞蛋白质的分子改变，这些亚群最初是从一个人类原发性结肠癌中分离出来的。命名为HCT 116b、HCT 116和HCT 116a的亚群在几种生物学特性的表达上表现出显著差异。通过SDS-PAGE分级并电泳转移到硝酸纤维素膜上的膜成分的免疫放射自显影分析，区分出最具侵袭性的肿瘤细胞亚群与中等侵袭性和最低侵袭性的亚群。发现分子量在116-120 kd、92 kd、55-66 kd和31 kd范围内的抗原表达升高与HCT 116a细胞中最具侵袭性的亚群相关。通过SDS-PAGE分级并固定在硝酸纤维素膜上的RCA I和WGA凝集素与膜成分的结合模式，也区分了细胞的三个亚群。HCT 116b细胞的RCA I与80-92 kd成分的结合增加以及HCT 116a细胞的WGA与120 kd成分的结合增加区分了这三个亚群。在用无磷酸盐培养基中的32Pi标记细胞后，对细胞磷蛋白谱的分析进一步区分出最具侵袭性的亚群与中等侵袭性和最低侵袭性的亚群。发现120 kd和250 kd核成分、30和90 kd胞质成分的高水平磷酸化以及较低分子量膜成分的低水平磷酸化与最具侵袭性的亚群相关。得出结论，具有不同生物学特性的肿瘤内结肠癌细胞亚群中存在膜抗原表达的差异、膜成分糖基化的差异以及细胞蛋白质的选择性磷酸化和/或去磷酸化。这些细胞蛋白质的生化改变可能在恶性细胞表型多样性和异质性的产生中起重要作用。
