ScienceDaily (Mar. 13, 2010) — When cells move about in the body, they follow a complex pattern similar to that which amoebae and bacteria use when searching for food, a team of Vanderbilt researchers has found.
New research reveals that when cells move about in the body, they follow a complex pattern similar to that which amoebae and bacteria use when searching for food. (Credit: iStockphoto/Sven Hoppe)
"As far as we can tell, this is the first time this type of behavior has been reported in cells that are part of a larger organism," says Peter T. Cummings, John R. Hall Professor of Chemical Engineering, who directed the study that is described in the March 10 issue of the Public Library of Science journal PLoS ONE.
The discovery was the unanticipated result of a study the Cummings group conducted to test the hypothesis that the freedom with which different cancer cells move -- a concept called motility -- could be correlated with their aggressiveness: That is, the faster a given type of cancer cell can move through the body the more aggressive it is.
"Our results refute that hypothesis -- the correlation between motility and aggressiveness that we found among three different types of cancer cells was very weak," Cummings says. "In the process, however, we began noticing that the cell movements were unexpectedly complicated."
...
Read more here/Leia mais aqui: Science Daily
1 Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee, United States of America, 2 Vanderbilt Integrative Cancer Biology Center, Nashville, Tennessee, United States of America, 3 Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America, 4 Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
Abstract
Background
Organisms, at scales ranging from unicellular to mammals, have been known to exhibit foraging behavior described by random walks whose segments confirm to Lévy or exponential distributions. For the first time, we present evidence that single cells (mammary epithelial cells) that exist in multi-cellular organisms (humans) follow a bimodal correlated random walk (BCRW).
Methodology/Principal Findings
Cellular tracks of MCF-10A pBabe, neuN and neuT random migration on 2-D plastic substrates, analyzed using bimodal analysis, were found to reveal the BCRW pattern. We find two types of exponentially distributed correlated flights (corresponding to what we refer to as the directional and re-orientation phases) each having its own correlation between move step-lengths within flights. The exponential distribution of flight lengths was confirmed using different analysis methods (logarithmic binning with normalization, survival frequency plots and maximum likelihood estimation).
Conclusions/Significance
Because of the presence of non-uniform turn angle distribution of move step-lengths within a flight and two different types of flights, we propose that the epithelial random walk is a BCRW comprising of two alternating modes with varying degree of correlations, rather than a simple persistent random walk. A BCRW model rather than a simple persistent random walk correctly matches the super-diffusivity in the cell migration paths as indicated by simulations based on the BCRW model.
Citation: Potdar AA, Jeon J, Weaver AM, Quaranta V, Cummings PT (2010) Human Mammary Epithelial Cells Exhibit a Bimodal Correlated Random Walk Pattern. PLoS ONE 5(3): e9636. doi:10.1371/journal.pone.0009636
Editor: Jörg Langowski, German Cancer Research Center, Germany
Received: September 18, 2009; Accepted: February 14, 2010; Published: March 10, 2010
Copyright: © 2010 Potdar et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This study was funded by National Cancer Institute grant: Multiscale Mathematical Modeling of Cancer Invasion (grant number: 5U54CA113007-02). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
* E-mail: peter.cummings@vanderbilt.edu
Because of the presence of non-uniform turn angle distribution of move step-lengths within a flight and two different types of flights, we propose that the epithelial random walk is a BCRW comprising of two alternating modes with varying degree of correlations, rather than a simple persistent random walk. A BCRW model rather than a simple persistent random walk correctly matches the super-diffusivity in the cell migration paths as indicated by simulations based on the BCRW model.
Citation: Potdar AA, Jeon J, Weaver AM, Quaranta V, Cummings PT (2010) Human Mammary Epithelial Cells Exhibit a Bimodal Correlated Random Walk Pattern. PLoS ONE 5(3): e9636. doi:10.1371/journal.pone.0009636
Editor: Jörg Langowski, German Cancer Research Center, Germany
Received: September 18, 2009; Accepted: February 14, 2010; Published: March 10, 2010
Copyright: © 2010 Potdar et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This study was funded by National Cancer Institute grant: Multiscale Mathematical Modeling of Cancer Invasion (grant number: 5U54CA113007-02). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
* E-mail: peter.cummings@vanderbilt.edu
+++++
