Recently, we asked several of Canada’s leading stem cell scientists to tell us about what they think will be the next big thing in regenerative medicine. Where do they see things going? What are they excited about? For today’s premier instalment, we interviewed Dr. Janet Rossant, Chief of Research and a Senior Scientist at The Hospital for Sick Children in Toronto and immediate past president of the International Society for Stem Cell Research. She provided the following highlights.
When I look broadly, I’m seeing a lot of excitement about being able to use stem cells to model human disease. Here in Toronto, we’ve made induced pluripotent stem (iPS) cells from patients with cystic fibrosis, cardiac diseases and autism. We’re beginning to use those cells to differentiate them into different cell types to study the diseases in a Petri dish. All of that is moving forward. We’re going to see more and more of that.
I think, though, that the area to watch is a little bit more than just taking iPS cells and growing them in a Petri dish in a flat culture but instead growing cells and making little organs or “organoids.” We’ve seen over the last year people making little organoids in a dish: gut organoids, stomach organoids. I’m expecting to see papers on lung organoids. This means we will be able to study diseases in new ways and use these organoids for doing drug screening.
We’re also seeing the first trials (by Viacyte, a California-based cell-therapy company) going forward with pancreatic progenitor cells for treating type 1 diabetes. We probably won’t get full results, because these are all Phase 1 trials, but we’re going to get some idea of the survival and effectiveness in a relatively short period of time. Canada will be one of the sites for that trial; Dr. James Shapiro (University of Alberta) is involved.
There have been good Canadian contributions to that. The Viacyte trial is done with pancreatic progenitors that will mature and make the right insulin producing cells. Other people feel you’d be better off starting with the insulin-producing cells and using those directly. A recent paper from Dr. Tim Kieffer (University of British Columbia) shows really good advances in generating functional beta cells. It gives you a lot of hope that this kind of trial, which is an early one, will be rapidly replaced by better trials and better cells. Dr. Cristina Nostro (University of Toronto) is also moving very fast at getting better and better pancreatic islet cells.
The technology that everybody is jumping on is genome editing. Now you can think not only about fixing people with stem cells, but you can think about fixing the genetic defects in people’s stem cells before you put them back. Certainly here at SickKids there are a number of people thinking in the very short-term mode about how they might translate that into gene therapy approaches to genetic diseases.
The expanded use of cell-based therapies — whether they are stem cells or other cells — is also having an impact. If we think about immunotherapy for cancer, we’re using either molecules or modified T-cells. We’re seeing cell-based therapies of all sorts coming forward.
We’re seeing expanded use of bone marrow transplantation for a wider range of autoimmune diseases.The trials that Dr. Harry Atkins (University of Ottawa) and others are doing on MS — those kinds of approaches are going to get more and more refined as we go forward.
Cardiac care is another area where we’re seeing clinical trials with many kinds of cells and molecules to treat heart disease. I think we’re going to see small incremental advances. A big advance has to come if we can actually fix the heart muscle. I know Dr. Gordon Keller (University of Toronto) and his colleagues are pushing very hard in that direction to try to move from cells in culture to bioengineered matrices of cells that you could think about using to replace damaged parts of the heart. Also, Dr. Michael Fehlings (University of Toronto) is very active in looking at a number of sources of cells that might be able to remyelenate axons in spinal cord repair.
These are all areas to watch in the future — the whole field is moving rapidly forward.