MIAMI (AFP) - An experimental drug treatment has opened a new door in regenerative medicine by helping lab mice regrow damaged liver, colon and bone marrow tissue, US researchers said Thursday.
If the therapy is found to work in humans, scientists say it may save the lives of people who are critically ill with colon or liver disease and possibly some cancers.
However, experts cautioned that the research is at a very early stage, and more work is needed before it can be tested in people.
The study led by researchers at Case Western Reserve and UT Southwestern Medical Centre is published in the journal Science.
"We are very excited," said co-author Sanford Markowitz, professor of cancer genetics at Case Western Reserve's School of Medicine.
"We have developed a drug that acts like a vitamin for tissue stem cells, stimulating their ability to repair tissues more quickly," he added.
"The drug heals damage in multiple tissues, which suggests to us that it may have applications in treating many diseases."
The drug is now known only as SW033291.
It can shut down the activity of a gene product found in all humans, 15-hydroxyprostaglandin dehydrogenase (15-PGDH).
That, in turn, allows room for more prostaglandin E2, which encourages many types of tissue stem cells to grow and promotes healing.
Researchers have performed a series of experiments, showing that SW033291 could inactivate 15-PGDH in a test tube, inside a cell, and when injected into lab animals.
Some mice were given lethal doses of radiation and then a partial bone marrow transplant. The mice that received SW033291 survived, while the others died.
Other studies showed mice given SW033291 recovered normal blood counts six days faster than mice that did not get the treatment.
Mice with ulcerative colitis were given the treatment and it "healed virtually all the ulcers in the animals' colons and prevented colitis symptoms," said the study.
"In mice where two-thirds of their livers had been removed surgically, SW033291 accelerated regrowth of new liver nearly twice as fast as normally happens without medication."
The drug showed no adverse side effects.
Researchers who were not involved with the work said the study showed promise, but urged a heavy dose of caution.
"The drug seems to be too good to be true," said Dusko Illic, a stem cell expert at Kings College London.
"We would have to be sure that nothing else was wrong with any organ in the body," because if there were cancer cells present, the treatment would likely cause tumour cells to grow along with other tissue.
However, Ilaria Bellantuono, an expert in stem cell science and skeletal ageing at the University of Sheffield, said a key part of the drug's promise could be in helping cancer patients, if it is proven safe.
The "treatment has the potential of boosting patents' resilience and improving their response to cancer treatment," said Bellantuono.
"This study is a proof of concept in mice and more experimental work is needed to verify the long term safety of such an approach but it surely shows promise."
Study authors said the first people to receive the experimental treatment in clinical trials would likely be patients who are receiving bone marrow transplants, have ulcerative colitis, or are undergoing liver surgery.