To pass through a narrow vessel, wandering malignant cells are arranged in a series one at a time, but continue to hold each other.
Not so long ago we talked about the fact that stray malignant cells that create metastases, we do not walk alone but in groups – so it is easier for them to take root in a new place and start the growth of secondary tumors. However, floating in the bloodstream, companies cancer cells have to pass through very narrow capillaries, through which a single cell is difficult to squeeze through.
Cancer cells, scrambling up through a 7-micrometer capillary. (Illustration of Au et al., PNAS 2016.)
“”
For a long time thought that the cell clusters can’t reach the small blood vessels, forming in front of them, real blood clots that can block blood flow. But then it turned out that the cell clusters through a capillary network still somehow pass. To understand how this occurs, the Toner Mehmet (Mehmet Toner) and his colleagues from Harvard Medical school has forced groups of tumor cells taken from blood samples of patients and from cell cultures, to pass through the microcapillaries with a diameter of 7 micrometers. In the video, which was made by the researchers, is seen as 10-20-cell clusters, stumbled on “narrowing the road”, just began to move in turns, one after another, and at the exit of the narrow portion again formed a more or less surround a clump.
The same thing has been seen in experiments with fish Danio rerio, whose capillaries are very similar to human in size, and blood pressure which is also close to that which is in human vessels. Complexes of tumor cells, injected embryos D. rerio, fish behaved in the capillaries just as artificial microchannels – they passed them, stretching in a chain of cells. It is worth emphasizing that the connection between the cells when passing through narrow places are not torn, that is, it was still a single cluster, just stretched out in a string.
However, as the authors work in an article in PNAS, under the influence of certain substances that weaken cell-cell interaction, cell group, stumbled on the capillary was broken up into smaller enterprises, or even in single cells. Given that circulating cancer cells, it is important to stick together, such medicines that would help to destroy the cell clusters, could play a role in the prevention of tumor metastasis.
On the other hand, evidence that a single circulating cells are less dangerous than cell clusters, not yet – it is possible that no special “anticlustering” the therapy here is not necessary. In addition, the results obtained should double-check it with human capillaries, and at the same time to clarify how such a cellular group acting on vascular “intersections”, in areas of branching capillaries.
According to the materials of The Scientist.
Author: Cyril Stasevich
Source: nkj.EN
