Bisgaard H C, Thorgeirsson S S
Laboratory of Experimental Carcinogenesis, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892.
J Cell Physiol. 1991 May;147(2):333-43. doi: 10.1002/jcp.1041470220.
The appearance of differentiated hepatocytes in the adult rat pancreas as well as pancreatic-type tissue in the adult rat liver can be experimentally induced (Reddy et al.: J. Cell Biol., 98:2082-2090, 1984; Rao et al., J. Histochem. Cytochem., 34:197-201, 1986). These observations suggest a lineage relationship between cell compartments present in rat liver and pancreas. The present data demonstrate that epithelial cell lines with almost identical phenotypes can be established from adult rat liver and pancreas. The established cell lines showed similar morphologies as established by light- and electron-microscopic studies. The cell lines showed a unique expression pattern of intermediate filament proteins. Vimentin, actin, and beta-tubulin were present in all cell lines. In addition, simple epithelial type II cytokeratins 7 and 8 were found to be coexpressed with the type I cytokeratin 14 in several of the cell lines. Neither the type I cytokeratins 18 and 19, which are the normal partners for cytokeratins 8 and 7 in filament formation, nor the type II cytokeratin 5 could be detected despite the fact that filaments were formed by both cytokeratins 8 and 14. This suggests that cytokeratin 14 acts as an indiscriminate type I cytokeratin in filament formation in the established cell lines. The cell lines expressed the same sets of LDH and aldolase isoenzymes and identical sets of glutathione transferase subunits. In addition, the epithelial cell lines from liver and pancreas were equally sensitive to the growth-inhibitory effects of TGF-beta 1. No expression of tissue- or cell-specific proteins such as alpha-fetoprotein, albumin, amylase, elastase, or gamma-glutamyl transpeptidase were detected. The almost identical phenotypes of the hepatic and pancreatic cell lines suggest that they may be derived from a common primitive epithelial cell type present in both rat liver and pancreas. In contrast to parenchymal cells, these cells have an extended capacity for proliferation in vitro and may represent a progeny from a "precursor" or "stem" cell compartment in vivo.
成年大鼠胰腺中分化肝细胞的出现以及成年大鼠肝脏中胰腺型组织的出现可以通过实验诱导产生（雷迪等人：《细胞生物学杂志》，98:2082 - 2090，1984；拉奥等人，《组织化学与细胞化学杂志》，34:197 - 201，1986）。这些观察结果表明大鼠肝脏和胰腺中存在的细胞区室之间存在谱系关系。目前的数据表明，可以从成年大鼠肝脏和胰腺建立具有几乎相同表型的上皮细胞系。通过光学显微镜和电子显微镜研究确定，所建立的细胞系具有相似的形态。这些细胞系显示出中间丝蛋白的独特表达模式。波形蛋白、肌动蛋白和β微管蛋白存在于所有细胞系中。此外，在几个细胞系中发现简单上皮II型细胞角蛋白7和8与I型细胞角蛋白14共表达。尽管细胞角蛋白8和14都形成了丝，但无论是细胞角蛋白8和7在丝形成中的正常伙伴I型细胞角蛋白18和19，还是II型细胞角蛋白5都未被检测到。这表明细胞角蛋白14在已建立的细胞系的丝形成中作为一种不加区分的I型细胞角蛋白起作用。这些细胞系表达相同的乳酸脱氢酶和醛缩酶同工酶组以及相同的谷胱甘肽转移酶亚基组。此外，来自肝脏和胰腺的上皮细胞系对转化生长因子β1的生长抑制作用同样敏感。未检测到甲胎蛋白、白蛋白、淀粉酶、弹性蛋白酶或γ - 谷氨酰转肽酶等组织或细胞特异性蛋白的表达。肝脏和胰腺细胞系几乎相同的表型表明它们可能源自大鼠肝脏和胰腺中共同存在的一种原始上皮细胞类型。与实质细胞不同，这些细胞在体外具有延长的增殖能力，并且可能代表体内“前体”或“干细胞”区室的后代。
