Rudnicki M A, Ruben M, McBurney M W
Department of Medicine, University of Ottawa, Ontario, Canada.
Mol Cell Biol. 1988 Jan;8(1):406-17. doi: 10.1128/mcb.8.1.406-417.1988.
P19 embryonal carcinoma (EC) cells are multipotential stem cells which can be induced to differentiate in vitro into a variety of cell types, including cardiac muscle cells. A cloned human cardiac actin (CH-actin) gene was transfected into P19 cells, and stable transformants were isolated. Low levels of CH-actin mRNA were present in transformed EC cells, but a marked increase in the level of CH-actin mRNA was found as these cells differentiated into cardiac muscle. The accumulation of CH-actin mRNA paralleled that of the endogenous mouse cardiac actin mRNA. A chimeric gene, which consisted of the CH-actin promoter linked to the herpes simplex virus thymidine kinase coding region, was constructed and transfected into P19 cells. In these transformants, the thymidine kinase protein was located almost exclusively in cardiac muscle cells and was generally not detectable in EC or other nonmuscle cells. These results suggest that the transfected CH-actin promoter functions in the appropriate developmental and tissue-specific manner during the differentiation of multipotential EC cells in culture.
P19胚胎癌细胞是多能干细胞，可在体外诱导分化为多种细胞类型，包括心肌细胞。将一个克隆的人心脏肌动蛋白（CH-肌动蛋白）基因转染到P19细胞中，并分离出稳定的转化体。在转化的胚胎癌细胞中存在低水平的CH-肌动蛋白mRNA，但当这些细胞分化为心肌时，CH-肌动蛋白mRNA水平显著增加。CH-肌动蛋白mRNA的积累与内源性小鼠心脏肌动蛋白mRNA的积累平行。构建了一个嵌合基因，其由与单纯疱疹病毒胸苷激酶编码区相连的CH-肌动蛋白启动子组成，并转染到P19细胞中。在这些转化体中，胸苷激酶蛋白几乎只存在于心肌细胞中，在胚胎癌细胞或其他非肌肉细胞中通常检测不到。这些结果表明，转染的CH-肌动蛋白启动子在培养的多能胚胎癌细胞分化过程中以适当的发育和组织特异性方式发挥作用。
