Possible role of retinoic acid binding protein in retinoid stimulation of embryonal carcinoma cell differentiation
Possible role of retinoic acid binding protein in retinoid stimulation of embryonal carcinoma cell differentiation
复制标题
视黄酸结合蛋白在类视黄醇刺激胚胎癌细胞分化中的可能作用
作者：
A. Jetten;M. Jetten
维甲酸是维生素A的天然和合成类似物，参与上皮组织1-3的维持和分化。此外，据报道，这些化合物抑制某些未转化和病毒和化学转化的细胞系4，5的生长。最近，研究表明，维甲酸促进胚胎癌细胞6，7，畸胎癌中存在的未分化的早期胚胎样细胞的分化。胚胎癌细胞系在分化能力上有很大的不同：区分了“多能”和“无能”细胞系8，9。与后者相比，多能胚胎癌细胞在注射到小鼠体内或在体外10中形成细胞聚集体时分化；一些细胞系即使在单层培养中也很容易分化。我们已经证明，维甲酸不仅能刺激多能胚胎癌细胞系的分化，还能诱导所谓的无效胚胎癌细胞系Nulli SCC1和6050AJ的分化。我们在这里表明，这种作用不仅限于维甲酸，而且其他几种维甲酸也有能力刺激至少一种胚胎癌细胞系PCC4.aza1R的分化。此外，我们提出的证据表明，维甲酸的作用可能是由维甲酸结合蛋白介导的。
RETINOIDS, naturally occurring and synthetic analogues of vitamin A, are involved in the maintenance and differentiation of epithelial tissue1–3. Furthermore, it has been reported that these compounds inhibit the growth of certain nontransformed and virally and chemically transformed cell lines4,5. Recently, it has been shown that retinoic acid stimulates the differentiation of embryonal carcinoma cells6,7, undifferentiated early embryo-like cells present in teratocarcinomas. Embryonal carcinoma cell lines differ widely in their capacity to differentiate: a distinction has been made between ‘pluripotent’ and ‘nullipotent’ cell lines8,9. In contrast to the latter, Pluripotent embryonal carcinoma cells differentiate when injected into mice8 or when cell aggregates are formed in vitro10; some cell lines differentiate quite readily even when grown in monolayer culture. We have shown7 that retinoic acid not only stimulates the differentiation of Pluripotent embryonal carcinoma cell lines, but also induces differentiation of the so-called nullipotent embryonal carcinoma cell lines nulli SCC1 and 6050 AJ. We show here that this effect is not limited to retinoic acid but that several other retinoids have the ability to stimulate differentiation of at least one embryonal carcinoma cell line, PCC4.aza1R. Furthermore, we present evidence to suggest that the action of retinoids may be mediated by a retinoic acid binding protein.