Fractal analysis and ionic dependence of endocytotic membrane activity of human breast cancer cells |
| |
Authors: | Monika Krasowska Zbigniew J. Grzywna Maria E. Mycielska Mustafa B. A. Djamgoz |
| |
Affiliation: | (1) Division of Cell and Molecular Biology, Neuroscience Solutions to Cancer Research Group, Imperial College London, Sir Alexander Fleming Building, South Kensington Campus, London, SW7 2AZ, UK;(2) Section of Physics and Applied Mathematics, Department of Physical Chemistry and Polymer Technology, Silesian University of Technology, Strzody 9, 44-100 Gliwice, Poland |
| |
Abstract: | The endocytic membrane activities of two human breast cancer cell lines (MDA-MB-231 and MCF-7) of strong and weak metastatic potential, respectively, were studied in a comparative approach. Uptake of horseradish peroxidase was used to follow endocytosis. Dependence on ionic conditions and voltage-gated sodium channel (VGSC) activity were characterized. Fractal methods were used to analyze quantitative differences in vesicular patterning. Digital quantification showed that MDA-MB-231 cells took up more tracer (i.e., were more endocytic) than MCF-7 cells. For the former, uptake was totally dependent on extracellular Na+ and partially dependent on extracellular and intracellular Ca2+ and protein kinase activity. Analyzing the generalized fractal dimension (D q ) and its Legendre transform f(α) revealed that under control conditions, all multifractal parameters determined had values greater for MDA-MB-231 compared with MCF-7 cells, consistent with endocytic/vesicular activity being more developed in the strongly metastatic cells. All fractal parameters studied were sensitive to the VGSC blocker tetrodotoxin (TTX). Some of the parameters had a “simple” dependence on VGSC activity, if present, whereby pretreatment with TTX reduced the values for the MDA-MB-231 cells and eliminated the differences between the two cell lines. For other parameters, however, there was a “complex” dependence on VGSC activity. The possible physical/physiological meaning of the mathematical parameters studied and the nature of involvement of VGSC activity in control of endocytosis/secretion are discussed. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|