(Press-News.org) (TORONTO, Canada – Nov. 8, 2012) – Canadian and Italian stem cell researchers have discovered a new "master control gene" for human blood stem cells and found that manipulating its levels could potentially create a way to expand these cells for clinical use.
The findings, published today online ahead of print in Cell Stem Cell, usher in a new paradigm for the regulation of human blood stem cells, says co-principal investigator Dr. John Dick, who holds a Canada Research Chair in Stem Cell Biology and is a Senior Scientist at University Health Network's McEwen Centre for Regenerative Medicine and Ontario Cancer Institute (OCI), the research arm of the Princess Margaret Cancer Centre. He is also a Professor in the Department of Molecular Genetics, University of Toronto.
"For the first time in human blood stem cells, we have established that a new class of non-coding RNA called miRNA represents a new tactic for manipulating these cells, which opens the door to expanding them for therapeutic uses," says Dr. Dick.
In 2011, Dr. Dick isolated a human blood stem cell in its purest form – as a single stem cell capable of regenerating the entire blood system – paving the way for clinical uses. He also pioneered the cancer stem cell field by identifying leukemia stem cells in 1994 and colon cancer stem cells in 2007.
OCI lead author Dr. Eric Lechman says the research team removed a master control gene – microRNA 126 (miR-126) – that normally governs the expression of hundreds of other genes by keeping them silenced, which in turn keeps the stem cells in a non-dividing dormant state. The method was to introduce excess numbers of miR-126 binding sites into the stem cells by using a specially designed viral vector.
"The virus acted like a sponge and mopped up the specific miRNA in the cells. This enabled the expression of normally repressed genes to become prominent, after which we observed a long-term expansion of the blood stem cells without exhaustion or malignant transformation," says Dr. Lechman.
Adds Dr. Dick: "We've shown that if you remove the miRNA you can expand the stem cells while keeping their identity intact. That's the key to long-term stem cell expansion for use with patients." The co-principal investigator was Dr. Luigi Naldini, Director, of the San Raffaele Telethon Institute for Gene Therapy, Milan.
Dr. Dick's research was funded by the Canadian Institutes of Health Research, the Canadian Cancer Society, the Terry Fox Foundation, Genome Canada through the Ontario Genomics Institute, the Ontario Institute for Cancer Research, the Canada Research Chair Program, the Ontario Ministry of Health and Long-Term Care, the Canada Foundation of Innovation, as well as The Princess Margaret Cancer Foundation.
###
About Princess Margaret Cancer Centre, University Health Network
Princess Margaret Cancer Centre and its research arm, Ontario Cancer Institute, have achieved an international reputation as global leaders in the fight against cancer and delivering personalized cancer medicine. The Princess Margaret, one of the top five international cancer research centres, is a member of the University Health Network, which also includes Toronto General Hospital, Toronto Western Hospital and Toronto Rehabilitation Institute. All are research hospitals affiliated with the University of Toronto. For more information, go to www.theprincessmargaret.ca or www.uhn.ca .
Stem cell scientists discover potential way to expand cells for use with patients
2012-11-09
ELSE PRESS RELEASES FROM THIS DATE:
Intensive farming with a climate-friendly touch: Farming/woodland mix increases yields
2012-11-09
This press release is available in Spanish and Portuguese.
Each year, huge carbon stores are lost as a result of deforestation. In South America, around four million hectares of forest are cut down every year. As a result, international climate protection programs are planning to financially compensate farmers who preserve forests or plant new trees. Demand for land is rising, however. And growing need for food and energy crops will inevitably lead to conflicts of interest over fertile land in countries such as Brazil and Ecuador.
Thomas Knoke and Michael Weber at Technische ...
Sweet new approach discovered to help produce metal casting parts, reduce toxicity
2012-11-09
CORVALLIS, Ore. – Based on a new discovery by researchers at Oregon State University, the world's multi-billion dollar foundry industry may soon develop a sweet tooth.
This industry, that produces metal castings used in everything from water pumps and jet engines to railroad and automobile parts, dates back thousands of years to before Greek and Roman times. It was important in the advance of human civilization, but still continues to evolve.
Some modern technologies use various types of "binders" to essentially glue together sands and other materials to form sophisticated ...
Preschoolers' counting abilities relate to future math performance, researcher says
2012-11-09
COLUMBIA, Mo. – Along with reciting the days of the week and the alphabet, adults often practice reciting numbers with young children. Now, new research from the University of Missouri suggests reciting numbers is not enough to prepare children for math success in elementary school. The research indicates that counting, which requires assigning numerical values to objects in chronological order, is more important for helping preschoolers acquire math skills.
"Reciting means saying the numbers from memory in chronological order, whereas counting involves understanding ...
Ovarian cancer patients have lower mortality rates when treated at high-volume hospitals
2012-11-09
New York, NY (Nov. 8, 2012) – A study by researchers at the Herbert Irving Comprehensive Cancer Center (HICCC) at NewYork-Presbyterian/Columbia University Medical Center, recently e-published ahead of print by the Journal of Clinical Oncology, suggests that women who have surgery for ovarian cancer at high-volume hospitals have superior outcomes than similar patients at low-volume hospitals.
The improved survival rate is not dependent on a lower rate of complications following surgery, but on the treatment of the complications. In fact, patients with a complication after ...
Study shows young adults with addiction benefit from active 12 step group participation
2012-11-09
CENTER CITY, Minn. (November 8, 2012) – Young adults undergoing addiction treatment benefit from regular participation in Twelve Step-based self-help groups after discharge, according to a naturalistic study published electronically and in the journal Drug and Alcohol Dependence. The study was conducted collaboratively by the Center for Addiction Medicine at Massachusetts General Hospital and Harvard Medical School and the Butler Center for Research at Hazelden.
"Very little is known about the effects of Twelve Step attendance and involvement on outcomes for young adults. ...
Medical devices powered by the ear itself
2012-11-09
Deep in the inner ear of mammals is a natural battery — a chamber filled with ions that produces an electrical potential to drive neural signals. In today's issue of the journal Nature Biotechnology, a team of researchers from MIT, the Massachusetts Eye and Ear Infirmary (MEEI) and the Harvard-MIT Division of Health Sciences and Technology (HST) demonstrate for the first time that this battery could power implantable electronic devices without impairing hearing.
The devices could monitor biological activity in the ears of people with hearing or balance impairments, or ...
A B C -- 1 2 3, but what is good for me?
2012-11-09
Philadelphia, PA, November 8, 2012 – The National Health and Nutrition Examination Surveys revealed that over 21% of children 2 to 5 years old were considered overweight or obese. Child care settings can serve as a platform to teach children about nutrition in our fight against childhood obesity, as nearly 50% of children in the United States under age 5 are enrolled in child care. In a new study released in the November/December 2012 issue of the Journal of Nutrition Education and Behavior, training child care providers about their role in children's healthful eating ...
Antioxidants may ease PAD blood pressure increase
2012-11-09
HERSHEY, Pa. -- Low antioxidant levels contribute to increased blood pressure during exercise for people with peripheral arterial disease, according to researchers at Penn State Hershey Heart and Vascular Institute.
Peripheral arterial disease, or PAD, affects an estimated 10 million Americans and increases the chance of death from a cardiovascular event. Reduced blood flow causes pain in the legs and increases blood pressure in people who have PAD. However, the causes of the disease are unknown.
"Past studies have shown that having low antioxidant levels and increased ...
Comet collisions every 6 seconds explain 17-year-old stellar mystery
2012-11-09
Every six seconds, for millions of years, comets have been colliding with one another near a star in the constellation Cetus called 49 CETI, which is visible to the naked eye.
Over the past three decades, astronomers have discovered hundreds of dusty disks around stars, but only two — 49 CETI is one — have been found that also have large amounts of gas orbiting them.
Young stars, about a million years old, have a disk of both dust and gas orbiting them, but the gas tends to dissipate within a few million years and almost always within about 10 million years. Yet ...
Is housework a health hazard? Sheet-Fitting palsy described by wake forest baptist physicians
2012-11-09
WINSTON-SALEM, N.C. – Nov. 8, 2012 – What do a tight, fitted bed sheet and a blood clot in the wrist have in common? Both are associated with a condition called sheet fitting palsy. True to its name, the palsy is reported in those who spend a long period of time repeatedly trying to pull a fitted bed sheet over the corner of a mattress. But it has also been reported in basketball players and in those who do push-ups as exercise.
The injury is caused by the continuous flexing movement of the wrist and results in a tiny stroke in the artery to the hand. The resulting ...