Stem Cells From Unfertilized Female Eggs

The finding was presented at the annual Clinical Congress of the American College of Surgeons (ACS) in New Orleans (LA, USA) in October 2004.

The researchers believe that parthenogenesis, the ability to created a cloned embryo from an egg with it being fertilized, may be an alternative source of stem cells that would not require human embryonic tissue. The stem cells obtained by this method, however, would not necessarily be a substitute for embryonic stem cells.

"One would never want to say that one cell type is going to be a replacement for another,” pointed out Dr. Anthony Atala, professor of surgery and director of the Wake Forest Institute for Regenerative Medicine, Wake Forest University School of Medicine (Winston Salem, NC, USA). "The different cell types are different options for the future. Some cell types are going to have pluses and others are going to have minuses.”

A big advantage of stem cells obtained through parthenogenesis is that they may be used in the same patient without immunosuppression therapy. In contrast, human embryonic stem cells would be immunologically different from the patient being treated and therefore the cells would be rejected unless the patient underwent immunosuppression.

"A woman produces an egg every 28 days. Unless it is fertilized, the egg is discarded. We may be able to take that egg, grow cells needed for a particular kind of therapy, and deliver them back to the patient,” explained Dr. Atala. " Since the cells would be genetically matched to the patient, they would not be rejected and immunnosuppression would not be needed.”

It is not yet clear how parthenogenesis-derived cells may be applied clinically. "We're looking at conditions that need cells for therapy,” said Dr. Atala. "The hope is that for any condition that requires cell or tissue therapy, this technology would have potential implications.”

In the study, the investigators took eggs from rabbits and activated them with electrical energy to induce cell division. Once a mass of cells was generated within the egg, the researchers removed them and grew them in culture. Cells that had specific markers consistent with the ability to transform into different cell lines were selected. These cells then were treated with growth factors to differentiate them into muscle, blood vessels, bone, and fat. Results showed that sufficient numbers of cells could be produced for cell or tissue-engineering purposes.


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