Normal Cells Have 'Personal Space' Issues

Normal tissue cells and I have something in common: If you crowd us, we'll kick you out.

According to ScienceDaily, researchers from the University of Utah's Huntsman Cancer Institute (HCI) have found that "normal epithelium tissue ejects living cells to maintain a steady population and ease overcrowding. This discovery has the potential to reveal what goes awry in cancer when cells do not turnover, but instead pile up."

Many types of cancer begin in the epithelium, the tissue layer that forms the outer and inner surfaces of the body, including the skin and the lining of the gastrointestinal tract.

The epithelium normally extrudes cells that die and/or grow out of control and overcrowd surrounding cells. In two separate experiments, researchers tested this process of cell extrusion and found that overcrowding makes certain cells leave to give other cells in the tissue enough room. However, when the channel controlling cell extrusion is blocked, cell masses form.

Jody Rosenblatt, PhD, assistant professor in the Department of Oncological Sciences at the University of Utah School of Medicine and an HCI investigator, told ScienceDaily:

In the polyps, which are precursors to colon cancer, there's a similar pile-up of cells. If [polyps] behaved as normal colon tissue, we would have seen cells extrude, but polyps don't seem to do it...

This is a basic discovery for which there may be exciting implications for diseases like asthma or colitis where too much cell death leads to poor barrier function and for cancer where there is not enough cell death.

You can read more about this study in Nature.

References:

• University of Utah Health Sciences (2012, April 19). Cells in normal tissue seem to have 'personal space' issues; Factor in maintaining healthy tissue. ScienceDaily. Retrieved April 24.
• George T. Eisenhoffer, Patrick D. Loftus, Masaaki Yoshigi, Hideo Otsuna, Chi-Bin Chien, Paul A. Morcos, Jody Rosenblatt. Crowding induces live cell extrusion to maintain homeostatic cell numbers in epithelia. Nature, 2012; DOI: 10.1038/nature10999.
• Eliana Marinari, Aida Mehonic, Scott Curran, Jonathan Gale, Thomas Duke, Buzz Baum. Live-cell delamination counterbalances epithelial growth to limit tissue overcrowding. Nature, 2012; DOI: 10.1038/nature10984.