One of the problems for rejuvenation therapy development is how to replace the bad old cells with good young cells. Chemotherapy used to remove stem cells successfully made room for therapeutic stem cells. Note that the use of chemotherapy for this purpose in humans would cause damage elsewhere in the body. We need far better ways to wipe out specific classes of cells without damaging other cell types.
An experimental procedure that dramatically strengthens stem cells' ability to regenerate damaged tissue could offer new hope to sufferers of muscle-wasting diseases such as myopathy and muscular dystrophy, according to researchers from the University of New South Wales (UNSW).
The world-first procedure has been successfully used to regrow muscles in a mouse model, but it could be applied to all tissue-based illnesses in humans such as in the liver, pancreas or brain, the researchers say.
The research team, which is based at UNSW and formerly from Sydney's Westmead Children's Hospital, adapted a technique currently being trialled in bone marrow transplantation. Adult stem cells are given a gene that makes them resistant to chemotherapy, which is used to clean out damaged cells and allow the new stem cells to take hold.
A paper detailing the breakthrough appears in the prestigious journal Stem Cells this week.
The ability of adult stem cells to regenerate whole tissues opens up a world of new possibilities for many human diseases, according to the lead authors of the paper, Professor Peter Gunning, Professor Edna Hardeman and Dr Antonio Lee, from UNSW's School of Medical Sciences.
The problem is that existing aged or diseased stem cells won't get out of the way. They outcompete the youthful new stem cells just by taking up space.
"The beauty of this technique is that chemotherapy makes space for stem cells coming into muscle and also gives the stem cells an advantage over the locals. It's the first strategy that gives the good guys the edge in the battle to cure sick tissues," Professor Gunning said.
The better parts of science fiction should become reality as soon as possible.
"What has been the realm of science fiction is looking more and more like the medicine of the future," he said.
Previous attempts have run up against a limit caused by the presence of existing stem cells. This means we really do need a method to kill off the old stem cells to make room for the new youthful and healthier stem cells.
The procedure solves one of the major hurdles involving stem cell therapy – getting the cells to survive for more than an hour or so after inserting them into damaged tissue.
"In muscle, most stem cells die in the first hour or are present in such low numbers that they are not much help," Professor Gunning said. "Until now, the new healthy cells had no advantage over the existing damaged tissue and were getting out-competed.
There's an obvious parallel here with cancer. We need to solve a very similar problem to kill cancer cells as we do to kill old stem cells. They are both cells our of bodies. They are hard to differentiate from cells we do not want to kill. This makes cancer such an incredibly hard disease to treat. My guess is we are going to need the biotechnology that gets developed to kill cancer cells to use to kill aged non-cancer cells to make room for youthful replacements.
|Share |||Randall Parker, 2009 March 08 04:31 PM Biotech Stem Cells|