Neural stem cell research could bring Parkinson's cure closer

Melbourne scientists have become the first in Australia to culture adult neural stem cells, bringing local medicine a step closer to a potential cure for Parkinson's disease.

The work, carried out at the Peter MacCallum Cancer Institute, validates a procedure performed by specialists at Cedars-Sinai Medical Centre and Celmed BioSciences in the United States.

Last month, doctors Toomas Neuman and Michel Levesque revealed they had successfully expanded neural stem cells taken from a Parkinson's patient's brain, induced them to differentiate into dopamine-secreting neurons, then delivered them back to the patient.

Presenting the work at the Annual Meeting of the American Association of Neurological Surgeons, they announced their 57-year-old patient had continued to improve and showed no symptoms as much as three years after treatment, demonstrating that adult neural stem cells derived from a patient's own tissue could be used as a source of dopamine neurons.

The head of the Peter MacCallum Institute's stem cell biology program, Assoc Prof Paul Simmons said his group had been in consultation with the American doctors for about 18 months and how now replicated their procedure for expanding neural stem cells.

"In this lab we are simply attempting to validate their findings and thus far it looks very good," Simmons said.

He said while the institute's facilities were well placed to run a human clinical trial of the procedure, such a study was still at least a year away.

The Melbourne arm of the research was initiated when the Spinal Cord Society of Australia approached Simmons' group with an offer to back efforts to import the Cedars-Sinai procedure.

The institute also gained financial backing from the Lion's Club this week, which announced two fellowships for Simmons and colleague Dr David Haylock to develop cellular therapies for the treatment of spinal cord injury.

The researchers have ethical approval to collect tiny pieces of brain tissue left over from surgery on epilepsy patients.

The tissue is then expanded up in the lab, with neural cells developing into clusters known as neural spheres that, when disaggregated, form further clusters.

Simmons said his group was now concentrating on developing methods of propagation of human neural stem cells with the capacity to produce dopamine.

"In Parkinson's patients an area of the brain known as the substantia nigra is deficient in dopamine-secreting neurons," he said. "If a patient is given dopamine the symptoms go away for a short time but then it will have no affect on the patient at all."

By contrast, he said the US patient demonstrated a sustained increase in dopamine production and remained symptom-free three years after treatment. "That's what we'd like to see happen here," Simmons said.

He said that after further pre-clinical validations, the next critical issue would be to examine how best to deliver the cells back to the patient in stereotactic surgery.

"This fellowship offers us a unique opportunity to conduct some groundbreaking work in the realm of stem cells," Simmons said. "With one in nine Australians suffering with Parkinson's disease, this research holds great potential for the treatment of those who have failed to respond to other therapies."