Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How are cells held together?

09.09.2005


At the Institut Curie, the CNRS team of Yohanns Bellaïche has just discovered a new cellular component that participates in the organization of cells in the epithelium. This tissue, which forms a barrier between our body and the outside world, is an extremely coherent structure of myriad cells that fit together according to very precise rules. This cohesion holds together the tissues that compose the organs and controls the "comings and goings" of various substances between the outside world and our body.


When cellular adhesives come unstuck… One of the components of the exocyst has been inactivated in these cells. The two cellular adhesives – cadherin (pink) and _-catenin (blue) – are dispersed through the cytoplasm instead of being localized essentially at the membranes, to form the intercellular junction. © J. Langevin/Institut Curie



The Institut Curie CNRS researchers’ discovery sheds light on how cells "stick together", thereby ensuring the cohesion needed for proper bodily functioning, but also clarifies the problems that may arise if this cellular cohesion is impaired. When tumor cells no longer stick together, they can move around and invade other tissues. This leads to a risk of propagation via metastases, which complicates the treatment of cancer.
These results are published in the September 2005 issue of Developmental Cell.

The epithelium lines all the cavities of our body. Like a border, it separates inside from out: the skin isolates us from the outside world, epithelial cells lining the small intestine separate the intestinal cavity – the "lumen" – from the rest of the body. The epithelium also regulates "toing and froing" across the border, since its cells are polar – they have a sort of compass which tells them which way is out and which in:



- This polarity controls the point of adhesion between cells, which are held together by adhesion proteins. If cellular cohesion is impaired, epithelial integrity is altered and in certain cases this can have unfortunate consequences (see "When cells go walkabout").

- Epithelial cells are directional. They have a so-called brush border – the apical surface(1) – which optimizes surface exchange with the outside.

The epithelium, the body’s "border guard"

Cell polarity regulates the flow of information between inside and out, controls the passage of various substances (water, ions, nutrients…) between body compartments, and filters the molecules to be transported, into the blood vessels, for example.

The polarity of epithelial cells is in part maintained by a highly organized transport network which ensures that molecules are correctly directed to their "place of work" where they can perform their specific tasks. Polarity is also involved in the distribution of membrane receptors that regulate cell growth. Loss of polarity due to failure of one of the cellular adhesives – a-catenin – leads to the appearance of tumor cells whose growth is perturbed(2).

Trafficking of cellular adhesives

At the Institut Curie, Yohanns Bellaïche’s CNRS team(3) has just shown that one of the transporters of certain molecules to the cell membrane, the exocyst complex(4), plays a key role in the transport of one of the cellular adhesives, cadherin, to the junction with the adjacent cell. There, cadherin joins two other proteins(5) equally vital for cellular cohesion. Together, these adhesion proteins hold the cells together.

CNRS scientists at the Institut Curie have for the first time found evidence that the exocyst plays a part in maintaining the polarity of epithelial cells, which are essential for proper bodily functioning.

This discovery also casts light on the risks associated with loss of this function. When tumor cells lose their capacity to adhere to neighboring cells, they are able to move around and invade other tissues, leading to a risk of metastases. Clear understanding of the mechanisms of cellular adherence could enable the formation of metastases to be limited by maintaining the cohesion of tumor cells.

Catherine Goupillon | alfa
Further information:
http://www.developmentalcell.com/
http://www.curie.fr

More articles from Life Sciences:

nachricht Researchers identify potentially druggable mutant p53 proteins that promote cancer growth
09.12.2016 | Cold Spring Harbor Laboratory

nachricht Plant-based substance boosts eyelash growth
09.12.2016 | Fraunhofer-Institut für Angewandte Polymerforschung IAP

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>