Scientists in Sydney have become the first in the world to use adult stem cells to regrow damaged muscle tissue, offering hope to sufferers of incurable diseases such as muscular dystrophy.

The breakthrough procedure has been proven to regenerate muscle in a mouse engineered to have an injured skeletal muscle, but the concept could also be applied to human diseases such as lung disorders, chronic liver disease, and types I and II diabetes.

The team of gene therapy, cancer and muscle disease experts solved one of the biggest hurdles involving stem cell therapy in solid organs - getting the donor cells to survive for more than an hour after they are inserted into the damaged host tissue.

The lead author, Peter Gunning, the head of the Oncology Research Unit at the University of NSW, said until now, the new healthy cells had no survival advantage over the dominant existing damaged tissue.

Furthermore, injected donor cells were almost immediately wiped out by the immune system.

"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.

The most well-established form of cell replacement therapy, bone marrow transplants, have been performed successfully for 40 years. However solid tissue such as muscle is much more complicated and previous trials have yet to work successfully.

Scientists from the Children's Hospital at Westmead and Sydney and NSW universities tried to enhance the stem cells' survival chances by inserting an artificial, harmless virus - called a vector - into the cells, making them resistant to chemotherapy.

The diseased tissue is then killed off by chemotherapy, leaving room for the healthy cells to engraft and propagate.

"It's the first strategy that gives the good guys the edge in the battle to cure sick tissues," Professor Gunning said.

The experimental technique, funded by the Oncology Children's Foundation and published in the journal Stem Cells, is still at the pre-clinical stage but Professor Gunning said human clinical trials could start within three to five years.

Source: Sydney Morning Herald