Top scientist backs both adult and embryonic cell research

Leading scientist Catherine Verfaillie has told a briefing in Melbourne it was "unfortunate" that her work was held up as evidence that embryonic stem cell research was unnecessary.

Verfaillie, a professor at the Stem Cell Institute at the University of Minnesota, is in Australia to meet with scientists from the National Stem Cell Centre.

Her research on adult stem cells shot to prominence in June this year, when she published a paper in Nature demonstrating that mesenchymal stem cells isolated from adult bone marrow were able to differentiate into a range of cell types.

The paper has been widely used by opponents of embryonic stem cell research around the world to back their claims that embryo research is unnecessary - a view not shared by Verfaillie herself.

Verfaillie said that the use of her research results in this way was unfortunate, and noted that her opinion on the use of embryonic versus adult stem cells had not been sought by the anti-embryo research lobby groups.

"We're excited about what we found but that doesn't mean we should shut down the research," she said.

In fact, Verfaillie's research team uses both adult and embryonic stem cells. She noted that researchers are using knowledge acquired from 30 years of embryonic stem cell research and applying it to the far younger adult stem cell field.

Verfaillie said that there were several important points that needed to be made about the significance of her research on adult stem cells. Most importantly, she said, her research needed to be repeated by other scientists.

In addition, problems with coaxing adult cells down particular developmental pathways had to be overcome before the cells would be of clinical use.

Significant steps

Verfaillie said that while it was relatively straightforward to push adult stem cells to develop into a variety of cell types in vitro, including those resembling neurons and other neural cells, hepatocytes and fibroblasts, they had not yet succeeded in getting cells to differentiate in vitro into heart cells, blood cells or insulin secreting cells.

She also noted that getting cells to correctly function in the appropriate tissue or organ might also be an issue, noting that for cells such as heart or liver cells, it would be important to make sure that it was functioning properly.

Verfaillie said there was a whole series of significant steps that needed to be taken before stem cells of either kind could be used in the clinic. These included getting a good understanding of the cocktail that needed to be used to induce differentiation into particular cell types, and development of separation techniques to ensure that differentiated cells would not be contaminated with the teratomic embryonic stem cells from which they were derived.

She also said that a clear understanding of adult stem cells and their characteristics was needed before clinical use. Extensive pre-clinical studies in rodents and larger animals would also be needed.

"Even though we are excited, we think it will take five or 10 or 15 years before they can be used in the clinic," she said. "If we stop embryonic stem cell research, we may stop research that can be used to treat diseases that are not treatable with adult stem cells."

Verfaillie is giving a public lecture at the University of Melbourne tonight.