Adult stem cell research adds fuel to local debate

New research suggesting adult stem cells could be as flexible as embryonic stem cells has re-ignited debate over whether controversial Australian laws to permit research on human embryos should go ahead.

In the University of Minnesota work, published in the journal Nature this week, researchers isolated and grew cells from the bone marrow of adult mice, which developed into those similar to ES cells.

The lead scientist, Catherine Verfaillie, said that when these cells were injected into early mouse embryos, they differentiated into "most if not all" of the cell types of the rodent.

Verfaillie said that although the cell population doubled in number more than 100 times, the colony showed no signs of genetic wear and tear and had active telomerase - the enzyme known to prevent ageing.

"Some of the animals are 40 per cent derived from the bone marrow stem cells, suggesting that the cells contribute functionally to a number of organs," she said in a statement.

Verfaillie said the implications of her group's findings were that the derived stem cells, known as multipotent adult progenitor cells (MAPCs) could be as adaptable as embryonic stem cells.

Other scientists in the field have welcomed the discovery with cautious optimism, describing the findings as fantastic but warning against over-interpretation.

Opponents of ES cell work have also leapt upon the research, saying it added weight to the argument that work should focus on the less controversial adult stem cells.

And with legislation allowing limited ES cell research about to go before Parliament, government MPs have used the US work as the basis for renewed calls for a total ban.

According to the draft legislation and in keeping with a deal struck between the Commonwealth and state governments, ES cell research using surplus IVF embryos is to be permitted with the permission of donors.

The Peter MacCallum Cancer Institute's head of Stem Cell Biology, Assoc Prof Paul Simmons, said that while the implications of the Verfaillie research were "huge", work should continue on both sides of stem cell research concurrently.

Simmons own work is focused on adult stem cells, namely mesenchymal stem cells found in bone and cartilage, but he is also part of the newly named Biotechnology Centre of Excellence for Stem Cells and Tissue Repair, which has projects involving adult and ES cells.

He said Verfaillie's work was fascinating, but said the fact so many population doublings were done in culture could have tainted the outcome.

"It needs to be reproduced in an independent laboratory to understand whether these cells with these properties truly exist in bone marrow naturally or if they are the product of extended in vitro culture," Simmons said, explaining that previous studies had shown such things could create genetic lesions.

"Do they naturally exist of have you created these cells because of culture doubling and have you induced genetic lesions that endow these cells with these properties?

"If that's the case, and you proceeded towards clinical trials, regulatory authorities would have a lot of concerns about it."

Simmons said that the research, which effectively produced cells resembling the properties of an "adult embryonic stem cell", offered a "lovely observation".

"It's far, however, from a situation where we are able to apply these cells clinically," he cautioned.