Jammed Cells Expose the Physics of Cancer
In 1995, while he was a graduate student at McGill University in Montreal, the biomedical scientist Peter Friedl saw something so startling it kept him awake for several nights. Coordinated groups of cancer cells he was growing in his adviser’s lab started moving through a network of fibers meant to mimic the spaces between cells in the human body.
For more than a century, scientists had known that individual cancer cells can metastasize, leaving a tumor and migrating through the bloodstream and lymph system to distant parts of the body. But no one had seen what Friedl had caught in his microscope: a phalanx of cancer cells moving as one. It was so new and strange that at first he had trouble getting it published. “It was rejected because the relevance [to metastasis] wasn’t clear,” he said. Friedl and his co-authors eventually published a short paper in the journal Cancer Research.
Two decades later, biologists have become increasingly convinced that mobile clusters of tumor cells, though rarer than individual circulating cells, are seeding many — perhaps most — of the deadly metastatic invasions that cause 90 percent of all cancer deaths. But it wasn’t until 2013 that Friedl, now at Radboud University in the Netherlands, really felt that he understood what he and his colleagues were seeing. Things finally fell into place for him when he read a paper by Jeffrey Fredberg, a professor of bioengineering and physiology at Harvard University, which proposed that cells could be “jammed” — packed together so tightly that they become a unit, like coffee beans stuck in a hopper.
Interesting reading via Quanta Magazine:
https://www.quantamagazine.org/20160816-researchers-unpack-a-cellular-traffic-jam/
Paper:
http://www.ncbi.nlm.nih.gov/pubmed/7553628?__hstc=13887208.99410c2723885d6232166f2ef2172374.1473185562296.1473185562296.1473185562298.2&__hssc=13887208.2.1473185562298&__hsfp=2269640345
http://www.sciencedirect.com/science/article/pii/S0301468113000170
#research #cancer #jammedcells #health #science
Interesting.
ReplyDeleteThe idea being that a jammed group of cancer cells migrate as a unit through the surrounding unjammed cells? Presumably, because cancer cells are growing quickly enough they keep themselves in a jammed state? (There are some vague similarities to crack propagation through polycrystalline metals.)
ReplyDelete(after reading the article more, it looks like they're saying the opposite of what I read: that jammed tissues prevent metastasis, and something involved with cancer is causing a phase transition to fluid movement that allows metastasis.)
The idea that cells move with intention in the first place is one that I have trouble getting my head around. I've always thought of stuff like blood cells distributing oxygen in terms of probability. Motive cells with cilia or flagella simply increasing the the rate of distribution through the medium.
ReplyDeleteBryce Etheridge: a lot of biology writers imply intention as shorthand, where they actually mean that the life forms that adopt one behavior outcompete all the lifeforms that adopt another behavior. (For instance, you can show that there is insufficient chemical gradient across a flagellum-equipped cell for it to be able to sense the gradient direction while static, so what they do is random tumble and movement, that slows down if they detect a higher concentration after movement.)
ReplyDeleteJohn Bump You are right, Intention was the wrong word. It just struck me from the animation how straight of a line that cell on the right seems to be moving in, but that's more about the animator than the cells. Cell movement by simple reaction to stimulus makes sense "higher concentration of X protein on this side of me, move towards or away from it".
ReplyDeleteIn such a way I can see non physically attached cells moving as groups in a kind of konga-line. One cell at the head moving in a semi-random direction. Each cell in the line trying to maintain contact with other cells that have a particular (cancer marker) protein in their cell walls.
Thank you for this. Now I understand a little more with what happened with dad.
ReplyDeleteJohn Bump it's funny that even in your description of why biologists (especially evolutionary biologists) use intention short hand language for characterizing the driver behind behaviour adaptation, you used the word adopt which implies a volitional act. :It's hard to speak any other way consistently without the verbs you use sounding stilted and repetitive.
ReplyDeleteSean Walker John Bump I suppose if someone were a strict biological determinist, not even human actions could be called intent. It would be the same stimulus reactions just at a much much higher order of complexity.
ReplyDeleteBryce Etheridge: I've read essays by several neurobiologists who say exactly that: they claim we rarely or never make conscious decisions. We make subconscious choices far before we realize we've made a choice, and then rationalize the choices we do make afterwards. (Some interesting stuff in a book called "what I believe but cannot prove" that is a collection of essays by experts in physics, cosmology, neurobiology, and others.) Supporting evidence for the choice idea is indications using brain scans that show our brains have made simple decisions (like which button to push) before subjects have been able to consciously process the information involved in making the choice, although a spate of recent articles about how dead salmon in fMRI machines have brain activity associated with visually processing and recognizing human faces is calling into question some of our ideas about what constitutes a valid experimental instrumentation setup for brain activity.
ReplyDelete