Peehl D M, Leung G K, Wong S T
Department of Urology, Stanford University School of Medicine, CA 94305.
Cell Tissue Res. 1994 Jul;277(1):11-8. doi: 10.1007/BF00303075.
Expression of certain cytokeratins can be indicative of the state of differentiation of epithelial cells. The basal cells in the normal adult human prostatic epithelium are characterized by the expression of cytokeratins 5 and 14, whereas the secretory luminal cells contain cytokeratins 8 and 18. Cells cultured from the prostatic epithelium expressed cytokeratins 5, 8, and 18, and thus had features of both basal and luminal cells. Certain growth-inhibitory conditions altered keratin expression in conjunction with growth modulation. Deletion of peptide factors and hormones from the culture medium induced the expression of cytokeratins 1 and 10, associated with a squamous phenotype. These same squamous keratins were found in very dense, stratified cultures that were maintained at confluency in standard, complete medium for extended periods. Retinoic acid enhanced the expression of secretory luminal cell-associated cytokeratins 8 and 18 in semi-confluent cultures. Other growth inhibitory factors such as suramin, transforming growth factor-beta, and interferon-gamma had no effect on keratin expression. These observations indicate that the differentiation of prostatic epithelial cells can be directed toward alternate pathways, either squamous or secretory, by different growth-inhibitory conditions. However, not all growth inhibitory factors altered differentiation, demonstrating that growth inhibition in itself is not a sufficient inducer of differentiation.
某些细胞角蛋白的表达可指示上皮细胞的分化状态。正常成年男性前列腺上皮中的基底细胞以表达细胞角蛋白5和14为特征，而分泌性管腔细胞含有细胞角蛋白8和18。从前列腺上皮培养的细胞表达细胞角蛋白5、8和18，因此具有基底细胞和管腔细胞的特征。某些生长抑制条件在调节生长的同时改变了角蛋白的表达。从培养基中去除肽因子和激素会诱导细胞角蛋白1和10的表达，这与鳞状表型相关。在标准的完全培养基中长时间维持汇合状态的非常致密的分层培养物中也发现了这些相同的鳞状角蛋白。视黄酸增强了半汇合培养物中与分泌性管腔细胞相关的细胞角蛋白8和18的表达。其他生长抑制因子，如苏拉明、转化生长因子-β和干扰素-γ，对角蛋白表达没有影响。这些观察结果表明，通过不同的生长抑制条件，前列腺上皮细胞的分化可以导向鳞状或分泌性等不同途径。然而，并非所有生长抑制因子都会改变分化，这表明生长抑制本身并不是分化的充分诱导因素。
