Transferrin receptor expression during exponential and plateau phase growth of human tumour cells in culture
- 1 January 1984
- journal article
- research article
- Published by Wiley in Journal of Cellular Physiology
- Vol. 118 (1), 6-12
- https://doi.org/10.1002/jcp.1041180103
Abstract
Transferrin receptor expression by the human tumour cell lines CCRF‐CEM leukaemia and PMC‐22B melanoma was studied, measuring the specific binding of fluorescein isothiocyanate (FITC)‐labelled transferrin using a fluorescence‐activated cell sorter. By measuring the fluorescence of cells stained at subsaturating concentrations of conjugate it was possible to calculate the average numbers of receptors per cell and the binding affinity by Scatchard analysis. These values (1.9 × 105 binding sites/cell, KA 1.2 × 109 M−1 for CCRF‐CEM during exponential growth and 6.9 × 104 binding sites/cell, KA 1.4 × 10−9 M−1 for PMC‐22B) are in close agreement with previously published data obtained using radiolabelled transferrin. The present method, however, allowed the transferrin receptor expression of individual cells within a population to be measured and thus it has been possible to test the hypothesis that transferrin receptor is a marker for cycling cells. Frequency‐distribution histograms of transferrin receptor showed a wide range of values for both cell lines during exponential growth. When the extreme ranges were sorted and the cells examined for cellular DNA content it was found that those with the highest transferrin receptor expression were enriched with cells in S, G2, and M phases of the cell cycle, whereas those with low transferrin receptor expression were mainly in G1. However, two‐parameter‐correlated dot plots of transferrin receptor expression versus DNA content showed there was considerable overlap between the ranges of receptor expression for the different cell cycle compartments. Using a stathmokinetic method we have measured the proportion of quiescent cells in fed plateau phase cultures. Transferrin receptor expression was downgraded under these growth conditions but, contrary to expectation, the decline affected the population uniformly, without the emergence of a distinct, transferrin receptor‐negative subpopulation corresponding to the increasing proportion of quiescent cells. Thus, although transferrin receptor expression bears some relation to cell cycle phase and reflects the proliferative activity of populations of cells, it is incapable of identifying individual cells which are out of cycle.Keywords
This publication has 20 references indexed in Scilit:
- Ubiquitous cell-surface glycoprotein on tumor cells is proliferation-associated receptor for transferrin.Proceedings of the National Academy of Sciences, 1981
- Human cell surface glycoprotein related to cell proliferation is the receptor for transferrin.Proceedings of the National Academy of Sciences, 1981
- Demonstration of the transferrin receptor in human breast cancer tissue. Potential marker for identifying dividing cellsInternational Journal of Cancer, 1981
- FMFPAK1: A program package for routine analysis of single parameter flow microfluorimetric data on a low cost mini-computerComputers and Biomedical Research, 1980
- A rapid single step staining technique for DNA analysis by flow microfluorimetry.Journal of Histochemistry & Cytochemistry, 1980
- Human cell-surface glycoprotein with unusual propertiesNature, 1980
- Identification of transferrin receptors on the surface of human cultured cells.Proceedings of the National Academy of Sciences, 1979
- Modulation of Transferrin Receptors in Bone Marrow Cells by Changes in Lipid FluidityBritish Journal of Haematology, 1979
- Modulation of cell surface iron transferrin receptors by cellular density and state of activationJournal of Supramolecular Structure, 1979
- THE PLASMA-TO-CELL CYCLE OF TRANSFERRIN*JCI Insight, 1963