Abstract
The pattern of surface proteins of different types of normal and transformed rat liver cells have been studied in culture by means of lactoperoxidase-catalysed iodination procedures, followed by SDS-gel electrophoresis. The cells examined were primary cultures of epithelial liver cells, long-term cultures of epithelial liver cells, in vitro transformed epithelial liver cell lines and liver tumour-cell lines; mesenchymal cells from liver and skin were also examined. The principal surface proteins of primary cultures of epithelial cells from adult or neonatal rats had components with mol. wts of 140,000-160,000, 100,000 and 40,000-70,000. A band that had the same position as fibronectin from mesenchymal cells was also present and this band, as well as other iodinated components, were less sensitive to trypsin than fibroblastic fibronectin. A similar pattern of iodinated proteins was seen in long-term cultures of epithelial liver cells, with a great reduction in the number and intensity of the bands in the mol. wt region below 100,000. Almost all the in vitro transformed and tumour epithelial cell lines contain a protein with a mol. wt 135,000 as one of the major iodinated bands, and in contrast to the observation in transformed fibroblasts, the fibronectin was retained by most of these transformed cell lines.
Highlights
Summary.-The pattern of surface proteins of different types of normal and transformed rat liver cells have been studied in culture by means of lactoperoxidasecatalysed iodination procedures, followed by SDS-gel electrophoresis
THE SURFACE of various nonepithelial cells, such as fibroblasts, myoblasts, vascular endothelial cells, glial cells, smooth muscle and primitive mesenchymal cells, contains a large external transformationsensitive (LETS) protein, fibronectin, which participates in cell-to-cell and cell-tosubstrate interactions and which decreases in quantity when cells are transformed (Hynes, 1976; Vaheri & Mosher, 1978)
The aim of the present studies was to compare surface proteins in primary or long-term cultures of liver epithelial cells originating from adult or neonatal rats with those in cultured mesenchymal cells, and to see whether any relationship exists between transformation and pattern of cell-surface proteins in liver epithelial cells
Summary
Cell cultures.-Primary cultures of liver epithelial cells from adult BDIV and BDVI rats (150-200 g), or from 3-5-day-old BDIV rats, were obtained by the method described by Williams & Gunn (1974). A long-term culture of epithelial liver cells was established and maintained as previously described (Montesano et al, 1973, 1975, 1977) or was established from primary cultures of. The cell homogenates were prepared by sonication; the protein concentrations in the supernatants, obtained after centrifugation at 16,000 rev/min, were 15-50 mg/ml in the primary cultures of liver epithelial cells (IAR-115, 128, 129, 130 and 140) and 2-3 mg/ ml in the long-term cultures of liver epithelial cells (IAR-2, 20, 27, 6, 6-1 and 6-1-RT7) (see Table). For antigen determination in cell lines, media were taken from cultures kept for 24-72 h without medium changes, and concentrated 30-fold with a Minicon A-25 concentrator before use. Mo., U.S.A.) 0-6 u/ml glucose oxidase (Sigma type VII)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
