Washington, April 13 (IANS) In a breakthrough, researchers have used tiny molecules called microRNAs to turn back adult mouse cells back to their embryonic state.

These reprogrammed cells are pluripotent, meaning that, like embryonic stem cells, they have the capacity to become any cell type in the body.

The findings suggest that scientists will soon be able to replace retroviruses and even genes currently used in lab experiments to induce pluripotency in adult cells.

This would make potential stem cell-based therapies safer by eliminating the risks posed to humans by these DNA-based methods, including alteration of the genome and the risk of cancer.

“Using small molecules such as microRNAs to manipulate cells will play a major role in the future of stem cell biology,” said study’s senior co-author Robert Blelloch, Centre for Regeneration Medicine and Stem Cell Research at the University of California, San Francisco (UCSF).

Scientists are interested in reprogramming because it would offer a way to create cells that provide a genetic match for individual patients.

A patient’s skin cells could be reverted to pluripotent cells in the culture dish and then prompted to differentiate into adult cells, such as those of the heart, lung and brain. These cells could then be transplanted into patients, without the fear of rejection.

The current finding comes on the heels of a study published by the same group in the December 2008 print edition of “Nature Genetics.” The study showed that microRNAs, which can be synthesized in the lab, encouraged embryonic stem cells to self-replicate, a finding that has implications for replicating stem cells in the culture dish and exploring stem cells’ role in cancers.

The study appeared in the advanced online edition of Nature Biotechnology and is scheduled for the May 8 print issue.

By rounak