ES cell research opponents cheer Griffith research

Opponents of embryonic stem cell research have leaped to congratulate Griffith University scientists, who yesterday announced details of research in which differentiated cells were successfully grown from adult stem cells.

Queensland National Party senator Ron Boswell described the advance as a "world breakthrough". And The Australian newspaper quoted Catholic archbishop George Pell as saying he would refer the research to Rome, and possibly put more Catholic funding into the work.

But one leading expert, Monash University's Prof Martin Pera, has warned that the Griffith research should not be hailed prematurely as equivalent in potential to embryonic stem cell research.

The research, launched in Brisbane yesterday by federal health minister Tony Abbott, has shown that adult stem cells harvested from the lining of the nose can form new cells for major organs including the brain, heart, liver and kidney, as well as muscle, blood and immune system cells.

Prof Alan Mackay-Sim -- deputy director of the university's Institute for Cell and Molecular Therapies -- presented evidence for the extraordinary clinical potential of adult stem cells from the olfactory mucosa in a paper in the journal Developmental Dynamics.

All organs and tissues harbour small, self-renewing populations of adult stem cells that possess varying capacities to differentiate into the various cell types of the host tissue, or sometimes into cells found in other organs.

But Mackay-Sim's team has shown that olfactory mucosal stem cells exposed to cocktails of cell-growth factors in culture, and in the body, have capabilities rivalling those of embryonic stem (ES) cells, which can differentiate into any cell in the body. They can differentiate in vitro into new neurons and glial cells -- the two major cell types in the brain -- as well as liver, heart and muscle cells.

Implanted into the bodies of chicks, they give rise to new heart, liver, kidney, brain and limb-bud cells. In rats, they form new bone marrow cells that give rise to blood and immune system cells.

According to a summary of the paper, olfactory mucosal stem cells exhibit most of the properties of embryonic stem cells. But they have a significant advantage: they do not form tumours or teratomas -- disordered, cancer-like masses of differentiated cells.

Used therapeutically, Mackay-Sim believes they could obviate the controversial practice of deriving embryonic stem cells from unwanted embryos created by in vitro fertilisation (IVF). Commonwealth legislation currently prevents researchers deriving ES cells from embryos created after April 5, 2002.

And olfactory mucosal stem cells could also render obsolete a technique called somatic cell nuclear transfer (SCNT), or 'therapeutic cloning' -- also currently banned under Commonwealth stem-cell legislation.

Senator Boswell, one of the most outspoken critics of embryonic stem cell research and SCNT therapy, said the advance had taken stem cell technology "a giant leap forward".

"This new adult stem cell technology now puts them way ahead of embryo stem cell research. Science has spoken loud and clear and come out on the side of adult stem cells," he said.

Boswell predicted the advance would revolutionise biotechnology programs in the stem cell field, as investors realised adult stem cells were the way of the future. "The Griffith research on adult cells means there will be no need to harvest millions of embryos, nor generate 'therapeutic' clones to overcome the rejection problem," he said.

'Breakthrough' claims premature

Prof Martin Pera, director of embryonic stem cell research at Monash University, said the Griffith University team's results provided evidence that neural stem cells could differentiate into a range of cell types -- at least in the sense that they produced specific protein markers characteristic of cells in different tissues.

But he said he agreed with the authors' own conclusion that the area remained highly controversial, because other research groups had previously reported similar results, which could not be replicated.

"It's premature to claim that these cells are equivalent in growth potential and developmental capacity to embryonic stem cells," Pera said. "The ability to multiply human neural stem cells in the laboratory is limited, and the data in this report and others do not demonstrate functional capacity of the differentiated cells."

He said it would be important for other laboratories to confirm and extend the Griffith studies, but described them as "very interesting".

"They clearly illustrate the limitations of our current understanding of the potential of adult stem cells, and they indicate why it is essential to carry out work in parallel with adult as well as embryonic stem cells," he said.

"A single report of this nature, in a highly controversial and evolving field, does not represent a foundation for national scientific policy."

Getting around cloning

SCNT stem cells are created by removing the nucleus of a donor egg cell or oocyte, and replacing it with a full complement of genetic material from one of the patient's own cells, which avoids rejection reactions. According to Mackay-Sim, stem cell transplants derived from the individual patient's own olfactory mucosa would be recognised as 'self' by the patient's immune system, avoiding rejection reactions. They would also not 'inherit' leftover mitochondrial DNA from the female donor of the oocyte.

Mackay-Sim's team is already using olfactory stem cells to investigate Parkinson's disease, schizophrenia, epilepsy and mitochondrial disorders.

Some Australian researchers have clamoured to study the development of inherited genetic disorders by creating SCNT cells from individuals with disorders like thalassaemia, cystic fibrosis and Duchenne muscular dystrophy. By harvesting olfactory stem cells from individuals born with these disorders, they would avoid the complexity -- and controversy -- involved in the SCNT technique.