CELLULAR AND MOLECULAR BIOLOGY OF THE HEPATIC STEM CELL COMPARTMENT

肝干细胞区室的细胞和分子生物学

• 批准号: 3774824
• 负责人: S S THORGEIRSSON
• 金额: --
• 依托单位: DIVISION OF CANCER EPIDEMIOLOGY AND GENETICS
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3774824
• 关键词: alpha fetoprotein; biomarker; carcinogenesis; cell differentiation; cell type; cellular oncology; gene induction /repression; gene interaction; genetic regulation; immunocytochemistry; intermediate filaments; laboratory mouse; laboratory rat; liver; liver cells; molecular biology; molecular oncology; neoplastic transformation; pancreas; vimentin

The research is focused on defining the cellular and molecular biology of the hepatic and pancreatic stem cell compartments in normal and neoplastic organs. We have recently reported that cell lines of nonparenchymal epithelial origin isolated from rat liver and pancreas express K8 and K14 but not K18 and K5, their normal partners in filament formation. However, upon spontaneous transformation and differentiation toward a hepatoblast- like progeny, K14 expression is abrogated and substituted by expression of K18. Immunocytochemical analysis of the cells in monolayer demonstrated that K8 as well as K14 were incorporated in the cellular cytoskeleton. Thus, in small nonparenchymal epithelial cell lines isolated from rat liver, K8 and K14 form the major intermediate filament network. Finally, we showed that a widely used antibody in studies of cell lineages in hepatic and pancreatic tissues and their neoplasms, the mouse monoclonal antibody OV-6, recognizes a common epitope in keratins 14 and 19. We further investigated if the expression of K14 could provide a lineage marker for this facultative stem cell compartment and its early progeny known as oval cells in the adult rat liver. Our results suggest that K14 and AFP are expressed in two different subpopulations of the early oval cell compartment. Similar results were obtained in an in vitro model in which spontaneous transformation of rat liver epithelial (RLE) cells appeared to mimic the process of early differentiation along the hepatic lineage in vivo. We demonstrated that undifferentiated RLE cells expressed K14 and vimentin, whereas transformation and differentiation to hepatoblast-like progeny resulted in an abrogation of K14 and vimentin expression and an induction of K18 and AFP. Taken together the in vivo and in vitro data indicate that K14 is expressed prior to AFP, when oval cells differentiate along hepatic as well as other cell lineages. Therefore, K14 expression may represent a valuable tool for studies on the mechanisms involved in the activation, proliferation and differentiation of the hepatic stem cell and oval cell compartments.

该研究的重点是定义细胞和分子生物学 正常和肿瘤细胞中的肝和胰腺干细胞区室 器官。 我们最近报道了非实质细胞系 从大鼠肝脏和胰腺中分离的上皮来源表达 K8 和 K14 但 K18 和 K5 则不然，它们是细丝形成过程中的正常伙伴。 然而， 自发转化和分化为肝母细胞 与后代一样，K14 表达被废除并被以下表达取代： K18。 单层细胞的免疫细胞化学分析表明 K8 和 K14 都被纳入细胞骨架中。 因此，在从大鼠分离的小型非实质上皮细胞系中 肝脏、K8 和 K14 形成主要的中间丝网络。 最后， 我们展示了一种在细胞谱系研究中广泛使用的抗体 肝和胰腺组织及其肿瘤，小鼠单克隆 抗体 OV-6，识别角蛋白 14 和 19 中的共同表位。我们 进一步研究 K14 的表达是否可以提供谱系 该兼性干细胞区室及其早期后代的标记 成年大鼠肝脏中称为卵圆细胞。 我们的结果表明 K14 和 AFP 在早期卵圆的两个不同亚群中表达 细胞室。 在体外模型中也获得了类似的结果 大鼠肝上皮（RLE）细胞的自发转化 似乎模仿了沿肝的早期分化过程 体内谱系。 我们证明未分化的 RLE 细胞 表达 K14 和波形蛋白，而转化和分化为 肝母细胞样后代导致 K14 和波形蛋白消失 K18 和 AFP 的表达和诱导。 综合体内 体外数据表明，当椭圆形时，K14 先于 AFP 表达 细胞沿着肝脏以及其他细胞谱系分化。 因此，K14 表达可能是研究 K14 的一个有价值的工具。 参与激活、增殖和分化的机制 肝干细胞和卵圆细胞区室。