Stem cell scientists discover genetic switch to increase supply of stem cells from cord blood

Dr. John Dick, a senior scientist at the Princess Margaret Cancer Centre, explains blood stem cells. #ConquerCancer


Dr. Dick: What we figured out is what keeps a blood stem cell going in the long-term. So, blood stem cells are really rare cells in our body, but they're the ones that have the property of building blood every day.

One of the things that makes them powerful is also that they can keep doing that for long periods of time, maybe even years. A single stem cell can stay active for a long time because it has this switch that keeps it functional for long periods of time. We call that "self-renewal," or the "stemness function." And people have been trying to figure out what are the switches that a stem cell has that have that property, and then how do they lose it when they start to not be a stem cell and they start to now make real blood.

And what we figured out is that switch. Now why is that important? It's important because one of the big problems that we have today is that we don't have enough stem cells that are useful for clinical therapy. So, stem cell therapy, blood stem cell therapy, is one of the most widely-used regenerative medicines that are available.

Every year, 40,000 people around the world get a blood stem cell transplant, mostly for their leukaemia or blood cancer therapy, so it's highly used. The problem is that two-thirds of people who need a transplant don't have a related donor.

One of the big sources of stem cells that would alleviate that problem, is actually the use of cord blood, because cord blood is very numerous and for the most part it's just thrown away, and there's a lot of stem cells in the cord blood and it's used very widely for therapy in children.

The problem is that most of the people who need it are in adults. They're much larger, they need more stem cells and there aren't enough stem cells in a single cord blood.

We've uncovered, by knowing what the switch is, what we figured out is that when a stem cell divides, it makes a lot of cells in the tier just below, just down straight from the stem cell. They're really good cells, it's just they can't keep going for long-term, and so what we've basically uncovered is a way to harness this switch by turning it on in a cell that normally wouldn't have it on, and now we've increased the number of stem cells that are available to us by many, many fold.

And so, this is a proof of concept, but we hope that in the long term this could be harnessed into a clinical therapy, we can now take advantage of all the cord blood cells that are now being collected in these various public cord blood banks, which are now blossoming and growing across the country.

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