Watch how cells squeeze through channels

Date:
October 6, 2020
Source:
Cell Press
Summary:
Observations of cells moving through small channels shed new light
on cell migration in 3D environments, researchers report. The
findings also reveal how cancer cells may penetrate tissues and
spread throughout the body.



FULL STORY ========================================================================== Observations of cells moving through small channels shed new light on cell migration in 3D environments, researchers report October 6 in Biophysical Journal. The findings also reveal how cancer cells may penetrate tissues
and spread throughout the body.


==========================================================================
"Our results describe how cells can migrate and deform through confined
spaces, providing potentially new ways to envision cell motility in small
blood capillaries in vivo," says senior study author Daniel Riveline of
the University of Strasbourg in France.

Cell migration plays a key role in a variety of biological phenomena,
ranging from early development to disease processes. But cell motility
has mainly been studied on flat surfaces rather than in 3D environments
similar to blood vessels and other structures commonly found in the
body. To address this gap, Riveline and his collaborators studied
cell motion in microfabricated channels that had either open or closed configurations (i.e., confined by three or four walls, respectively). In addition, some channels were straight, whereas others had various
bottlenecks to mimic cell blockage in small veins.

As expected, fibroblasts moved freely in straight channels. But in the
presence of bottlenecks, the nucleus sometimes prevented cell passage,
causing pauses in cell motion. Other times, the cells anchored and pulled locally to deform the nucleus and allow cell passage. Additional results suggested that cells would not be able to change their direction of
motion when entering a sufficiently small capillary, and that chemical gradients can induce directional motion.

The researchers also studied the movements of oral squamous epithelial
cells, including some with mutant keratin protein implicated in squamous cancers. In normal cells, keratin accumulated at the rear of the nucleus
during passage through bottlenecks, potentially to facilitate deformation
of the organelle. By contrast, the mutant cells could not pass through bottlenecks, indicating that defects in keratin impair motion in confined spaces, possibly by preventing the nucleus from deforming. The findings
also suggest that squamous cancer cells could be blocked within small capillaries, potentially allowing them to penetrate tissues.

"Because initial arrest in the capillary is critical for tumor cells
to metastasize to secondary sites in distant organs, blockage by
mutant keratin may provide advantages for tumor seeding, survival, and proliferation," Riveline says. "Future studies could take this channel
strategy to identify signaling networks that are modified in the context
of cancer."

========================================================================== Story Source: Materials provided by Cell_Press. Note: Content may be
edited for style and length.


========================================================================== Journal Reference:
1. Emilie Le Maout, Simon Lo Vecchio, Praveen Kumar Korla, Jim
Jinn-Chyuan
Sheu, Daniel Riveline. Ratchetaxis in Channels: Entry Point and
Local Asymmetry Set Cell Directions in Confinement. Biophysical
Journal, 2020; 119 (7): 1301 DOI: 10.1016/j.bpj.2020.08.028 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/10/201006114305.htm

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