Hunt R C, Marshall L M
Mol Cell Biol. 1981 Dec;1(12):1150-62. doi: 10.1128/mcb.1.12.1150-1162.1981.
Human erythroleukemic (K562) cells differentiate along the erythroid differentiation pathway in vitro when 0.05 mM hemin is included in the growth medium. In the presence of the inducer the cells continue to proliferate and, after a delay of 24 to 48 h, start to synthesize hemoglobin. However, during differentiation, no changes in the major cell surface proteins were detected using lactoperoxidase-catalyzed iodination, and no change in the synthesis of spectrin, the major cytoskeletal protein of the mature erythrocyte, was detected by specific immune precipitation. Despite this absence of major changes in cell surface proteins, profound changes take place in the organization of the cell membranes. A process similar but not identical to the enucleation observed in erythroid differentiation in vivo occurs in which a smooth-surfaced cell, about 10 micrometers in diameter, is divided from the nucleus-containing part of the cell. With the exception of ribosomes, these reticulocyte-like cells contain no organelles when examined by transmission electron microscopy, but contain much of the parent cell's hemoglobin, spectrin, and glycophorin.
当生长培养基中含有0.05 mM氯化血红素时，人红白血病（K562）细胞可在体外沿红系分化途径分化。在诱导剂存在的情况下，细胞继续增殖，延迟24至48小时后开始合成血红蛋白。然而，在分化过程中，使用乳过氧化物酶催化碘化未检测到主要细胞表面蛋白的变化，通过特异性免疫沉淀也未检测到成熟红细胞的主要细胞骨架蛋白血影蛋白合成的变化。尽管细胞表面蛋白没有重大变化，但细胞膜的组织发生了深刻变化。发生了一个与体内红系分化中观察到的去核过程相似但不完全相同的过程，即一个直径约10微米、表面光滑的细胞与细胞含核部分分离。除核糖体外，通过透射电子显微镜检查，这些网织红细胞样细胞不含细胞器，但含有母细胞的大量血红蛋白、血影蛋白和血型糖蛋白。
