Canadian Researchers Find THE Stem Cell for the Human Blood System, Opening a New Door to Regenerati
Lacking an influential religious right wing, Canada is a leader in stem cell research. Indeed, much of the fundamental, early proof of stem cells is credited to Canadian researchers. Here’s a Canadian-centric timeline of stem cell discoveries.
Now the Canadians have made another breakthrough stem cell discovery. Specifically, they’ve found and isolated the stem cell capable of generating the entire blood system. ScienceDaily presents the summary here. The full paper is published in the prestigious journal, Science, and is here.
The lead researcher for this project, Dr. John Dick, is well-known for blood and stem cell discoveries, and cancer research. In 2007, for example, his team made Science (and ScienceDaily) with research work that opened the door to using stem cells to create and track the leukemia process from the very beginning of that form of blood cancer. In January, 2011, Dr. Dick’s team built on that work and published in Nature this groundbreaking paper on genetic diversity in leukemias, as summarized here by ScienceDaily. The research proved that in at least the ALL form of leukemia, the tumors are NOT all alike. That is, they are not all one malignant cell endlessly dividing to spew out exact replicas. Instead, at least in ALL leukemias, there are multiple different forms of cancer cells. This discovery helps to explain why chemotherapy sometimes fails to prevent a later relapse – the chemo wiped out one line of cancerous cells but not another.
Finding the ultimate "parent" blood stem cell is important for multiple reasons. One is that it shows the value of new tools. The team used high volume flow cytometry to find the parent stem cell. That tool en essence screens huge volumes of cells to find a specific cell of interest. Improved versions of the tool may allow screening the blood of known of blood cancer patients to find the variant lines of cancer cells. If done post-therapy, that could help determine if every line of cancer cell has been killed.
On finding the parent stem cell itself, the finding offers a start towards developing more forms of regenerative medicine to save the lives of cancer patients. Today’s stem cell (bone marrow) transplants are the original form of regenerative medicine as the immune system is wiped out and then regenerated from the transplanted cells. The procedure imposes a significant risk of death, and a stunning burden on the body and mind of cancer patients, albeit today’s patients suffer and die less than did patients transplanted in past decades. And, there is the ceaseless problem of finding donor cells, a challenge made even harder by today’s increased ethnic diversity. So, for today, preserving cord blood is/should be a "no brainer" for any financially capable family, and registering to donate bone marrow is painless, easy and one of the few ways each of us can physically contribute to trying to save lives. This "New Year’s resolution" post outlines the how and why of cord blood preservation and bone marrow registration, with links to relevant agencies and services.
For the future, Dr. Dick and others hope to find ways to use the parent stem cells to regenerate non-cancerous forms of the myriad forms of blood cells, and to help treat other blood diseases. Here are key excerpts from the ScienceDaily summary:
"Dr. Dick works out of UHN’s Ontario Cancer Institute (OCI) — the venerable institution where stem-cell science began in 1961 with the original discovery of Drs. James Till and Ernest McCulloch — and McEwen Centre for Regenerative Medicine with the next generation of stem-cell scientists focused on developing better and more effective treatments for heart disease, diabetes, respiratory disease and spinal cord injury.
The 1961 Till and McCulloch discovery quickly led to using stem cells for bone marrow transplantation in leukemia patients, the most successful clinical application so far in what is now known as regenerative medicine and a therapy that is used to treat thousands of patients annually around the world.
"Ever since stem-cell science began," says Dr. Dick, "scientists have been searching for the elusive mother lode — the single, pure stem cell that could be controlled and expanded in culture prior to transplantation into patients. Recently scientists have begun to harness the stem cells found in the umbilical cord blood; however, for many patients a single donor sample is not large enough to use. These new findings are a major step to generate sufficient quantities of stem cells to enable greater clinical use and thus move closer to realizing the promise of regenerative medicine for patients."
Along the way, scientists have indeed mapped many vital signposts regarding stem-cell subsets and specialization. Last year, Dr Dick’s team reported isolating the more specialized progenitor cells that lie downstream of the stem cell. This latest discovery was enabled by hi-tech flow cytometry technology: a process that rapidly sorts, sifts and purifies millions of blood cells into meaningful bins for scientific analysis. Now, stem-cell scientists can start mapping the molecular switches that guide how "normal" stem cells behave and endure, and also characterize the core properties that distinguish them from all other blood cell types.
This discovery is the one Dr. Dick has personally been seeking ever since 1988 when he developed the first means of studying human blood stem cells by transplanting them into immune-deficient mice, research that was also published inScience. "Back then, our goal was to define single human stem cells. With advances made in technology, twenty-three years later, we have."