Posted on 12/04/2006 8:26:20 PM PST by neverdem
A sugar molecule present on embryonic stem cells also has been found on the surface of a type of adult stem cell, a discovery that may help researchers isolate and purify adult stem cells for use in therapies aimed at bone healing, tendon repair and cartilage regeneration, researchers at UT Southwestern Medical Center report.
The molecule, called SSEA-4, was found on the surface of certain stem cells in bone marrow that give rise to fat, cartilage and bone. These so-called mesenchymal cells are a tiny component of bone marrow; the vast majority of bone marrow is made up of hematopoietic stem cells, which give rise to blood and immune cells.
Dr. Rita Perlingeiro, assistant professor in the Center for Developmental Biology and of molecular biology, said detecting SSEA-4 will aid in singling out the mesenchymal stem cells, or MSCs, for more detailed scientific study as well as for possible medical applications. The cells have shown promise in early clinical studies elsewhere, where scientists tested their use to repair bone defects and to attenuate the effects of bone loss in diseases such as osteoporosis.
The study is available online and will be published in the Feb. 15 issue of the journal Blood.
Although mesenchymal cells were discovered in the 1970s, researchers still use decades-old methods to isolate them from bone marrow, said Dr. Perlingeiro, who led the research.
Exploiting the sugar molecule as a biological marker will boost researchers' ability to obtain a purer, more homogeneous population of MSCs. That's an important consideration, for example, in applications such as tissue engineering, where only bone-generating cells are needed. Such cells are being tested by a number of researchers for their ability to grow fat, cartilage and bone on special biomaterial-based scaffolding, with the goal of producing soft tissue for reconstruction or augmentation, or to shore up bones left fragile by age or disease.
"With a purer cell population, you should have a more effective therapy," Dr. Perlingeiro said.
The SSEA-4 molecule was known to be on the surface of embryonic stem cells, as well as on embryonic carcinoma cells, the malignant counterparts of embryonic stem cells.
Dr. Perlingeiro's ongoing studies also suggest that the SSEA-4 molecule might be present in other tissues, leading to the intriguing possibility that the SSEA-4 molecule could be a marker for "stemness," she said.
"The discovery of this molecule on MSCs was surprising, and is important to further our understanding of the biological nature of adult stem cells," Dr. Perlingeiro said. "We are also interested in learning whether SSEA-4 is expressed on other stem cells, such as those for muscle.
"It could actually be useful where we see less of it, as in tissues with very few stem cells. This marker could help us separate out those rare cells more easily."
She and her team also are investigating the SSEA-4 molecule's relationship to cancer stem cells, those cells in a tumor that behave like stem cells in that they self-renew and maintain the cancer even if most of the tumor is destroyed by radiation or chemotherapy.
"Is the expression of this marker elevated in a tumor" If so, perhaps it might be useful to identify cancer stem cells, but we don't know yet," Dr. Perlingeiro said. "That would be a very beneficial application, not just for guiding therapy, but also for early cancer detection and perhaps prevention."
Other researchers in the Center for Developmental Biology involved in the research were co-lead authors Drs. Eun Ji Gang and Darko Bosnakovski, both postdoctoral research fellows; and Camila Figueiredo, a Ph.D. student. Jan Visser from ViaCell Inc. also contributed.
The research was supported by the Dr. Bob and Jean Smith Foundation.
adult stem cells
No media attention.
SC Ping
This is a good discovery.
Eventually, we may hope to discover the intricate clockwork mechanisms of embrionic cells that guide them to develop into the astronomical varieties which comprise a human body.
With proper understanding, we may rejuvenate certain tissues, or guide the growth of replacement tissues, such as teeth.
The ethical way to do these things is to incubate cells from the individual patient, and develop the treatment tissues from those lines.
My mothers' Doctor has been fighting to save her legs (diabetes, no circulation etc.) from the knees down for months. She has had partial amputation on one foot already.
A few weeks ago when I visited her there was dramatic improvement.
I asked her what miracle happened.
She said the Dr. is giving her something called "adult something cells". I verified they are stem cells with the nurses. She has no clue as to what they are. She is just happy to not be having more amputations.
One leg has no bandages for the first time since March. Her other leg is looking pinkish down to the ankle area, where the bandage starts.
It sounds like something to induce angiogenesis, the growth of blood vessels toward the site of an injury.
It's one of the tricks that cancers learn, in order to be invasive.
It could also be precursor cells for developing such blood vesels.
I have long thought that studying cancer was also a way of studying and developing human longevity.
..........so keep the funding coming, OK ?
..........so keep the funding coming, OK ?
This is about findings from adult stem cells. So keep the less than useful comments coming, OK?
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I'll bet you a $100 that within 5 years there still won't be an effective disease treatment that is performed using embryonic stem cells.
Adult stem cell yep. But gee, adult stem cell treatments can't be patented... and no life gets destroyed.
Bump
I don't necessarily disagree with you.
The developmental problem for such researchers is that embrionic stem cells from destroyed fetuses are plenipotent; they are intended, and prepared to gradually change into whatever tissue their local environmental signals indicate to them. We don't understand how that works well enough to use them safely, (thank God.)
Adult stem cells are simply further along that line, having already gone through numerous cell division and guideline genetic checkmark procedures. That and the collection process are the only differences.
They are substantial differences. The number of cell divisions to reach even the placental or cord blood stage is enormous. And we are all familiar with the ethical lapses that allow embrionic stem cells to be "collected."
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