'Pure' human blood stem-cell discovery opens door to expanding cells for more clinical use

July 7, 2011 in Medical research

For the first time since stem cells were discovered here 50 years ago, scientists have isolated a human blood stem cell in its purest form – as a single stem cell capable of regenerating the entire blood system. This breakthrough opens the door to harnessing the power of these life-producing cells to treat cancer and other debilitating diseases more effectively. The study is published today in Science.

"This discovery means we now have an increasingly detailed road map of the development system including the much sought after stem cell," says principal investigator John Dick, who holds a Canada Research Chair in Stem Cell Biology and is a Senior Scientist at the McEwen Centre for Regenerative Medicine and the Ontario Cancer Institute, University Health Network (UHN).

"We have isolated a single cell that makes all arms of the blood system, which is key to maximizing the potential power of for use in more clinical applications. Stem cells are so rare that this is a little like finding a needle in a haystack."

Dr. Dick, who pioneered the field of cancer stem cells with previous discoveries in human leukemia and colon cancer, also developed a way to replicate the entire human leukemia disease process using genetically engineered mice. As well as being a Senior Scientist at UHN's Princess Margaret and Toronto General Hospitals, he is a Professor in the Department of Molecular Genetics, University of Toronto, and Director of the Cancer Stem Cell Program at the Ontario Institute for Cancer Research.

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 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. The discovery published today 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 in Science. "Back then, our goal was to define single human stem cells. With advances made in technology, twenty-three years later, we have."

More information: Paper online: http://www.sciencemag.org/lookup/doi/10.1126/science.1201219

Provided by University Health Network

5 /5 (3 votes)  

Rank 5 /5 (3 votes)
Related Stories
Relevant PhysicsForums posts

More news stories

Study reveals new mechanism for estrogen suppression of liver lipid synthesis

By discovering the new mechanism by which estrogen suppresses lipid synthesis in the liver, UC Irvine endocrinologists have revealed a potential new approach toward treating certain liver diseases.

Medical research created 17 hours ago | popularity not rated yet | comments 0 | with audio podcast

MRI-based measurement helps predict vascular disease in the brain

Aortic arch pulse wave velocity, a measure of arterial stiffness, is a strong independent predictor of disease of the vessels that supply blood to the brain, according to a new study published in the June issue the journal ...

Medical research created 17 hours ago | popularity not rated yet | comments 0

Antibiotics: A new understanding of sulfonamide nervous system side effects

Since the discovery of Prontosil in 1932, sulfonamide antibiotics have been used to combat a wide spectrum of bacterial infections, from acne to chlamydia and pneumonia. However, their side effects can include serious neurological ...

Medical research created 19 hours ago | popularity not rated yet | comments 0 | with audio podcast

Scientists discover molecule triggers sensation of itch

Scientists at the National Institutes of Health report they have discovered in mouse studies that a small molecule released in the spinal cord triggers a process that is later experienced in the brain as ...

Medical research created 19 hours ago | popularity 5 / 5 (2) | comments 0 | with audio podcast

Discarded immune cells induce the relocation of stem cells

Spanish researchers have discovered that the daily clearance of neutrophils from the body stimulates the release of hematopoietic stem cells from the bone marrow into the bloodstream, according to a report published today ...

Medical research created 21 hours ago | popularity 5 / 5 (2) | comments 0


Engineered cytomegalovirus protects monkeys from HIV equivalent

(Medical Xpress)—A new study by researchers in the US has shown that an ancient virus can be modified to help in the fight against the simian immunodeficiency virus SIV, which is the equivalent in monkeys ...

Help at hand for people with schizophrenia

How can healthy people who hear voices help schizophrenics? Finding the answer for this is at the centre of research conducted at the University of Bergen.

Breathing exercises help veterans find peace after war, scholar says

(Medical Xpress)—Research by Stanford scholar Emma Seppala at the Center for Compassion and Altruism Research and Education found that post-traumatic stress disorder decreased in veterans who participated ...

Do doctors understand the individualisation of treatments?

The individualisation of drug treatments to support patients to self-manage their conditions is a concept that sits at the heart of policy, but a recent study in BMJ Open shows that there is no concrete defini ...

Reducing experimental inflammatory arthritis

(Medical Xpress)—UCD researchers led by Conway Fellow, Professor David Brayden in UCD School of Veterinary Medicine have successfully reduced inflammation in the swollen arthritic knees of a murine model using a novel nanoparticle.

Ground breaking cancer research finds immune system link

(Medical Xpress)—Curtin University researchers have found evidence that targeting specific cells in the body can reverse the effects of cancer on the immune system.