Researchers are reporting a significant development in the process of creating stem cells that could allow treatment of some degenerative human diseases.

Researchers in the study published this week in the journal Nature say the result removed one cause of failure in the process.

Stem cells derived from immature female egg cells called oocytes, whose genetic material has been replaced by that of a non-reproductive cells, known as somatic cells, could allow for treatment of some degenerative human diseases, researchers say.

The advance does not have immediate clinical applications because the stem cells are not compatible with the patient's tissue.

The finding published this week by the New York Stem Cell Foundation comes from research involving 270 oocytes from 16 women, which created 13 early stage embryos known as blastocysts.

Such stem cells might be useful for a process called cell replacement therapy. The therapy involves replacing dead cells with new and healthy ones, thereby restoring functions lost through damage or disease.

Oocyte development after the genetic material was replaced stops at a late stage of embryo division in association with certain genetic copying abnormalities.

However if the genetic material is not removed, and only the genetic material from the somatic cell is added, the resulting cell group develops to the early embryo – or blastocyst - stage, researchers said.

The stem cell lines derived from the blastocysts differentiate into cell types that are the embryonic source of all cells in the body, and the somatic cell is programmed to develop into multiple cell types.

“This result demonstrates the feasibility of reprogramming human cells using oocytes and identifies removal of the oocyte genome as the primary cause of developmental failure after genome exchange,” researchers said.

Robert Lanza, chief scientific officer at Advanced Cell Technology, a company in Santa Monica California, told Nature the study shows the "enormous power of this technology."

However he added that the method has never been tried before "because it's of no clinical relevance." He said stem cells produced contained an extra set of chromosomes which are not compatible with the patient's tissue.

Photo above:

The center cluster of cells, colored blue, shows a colony of human embryonic stem cells. These cells, which arise at the earliest stages of development, are capable of differentiating into any of the 220 types of cells in the human body and can provide access to cells for basic research and potential therapies. This image is from the lab of the University of Wisconsin-Madison's James Thomson.

Credit: Clay glennon, University of Wisconsin-Madison