'Cloning' used to grow tailor-made stem cells in humans
SCIENTISTS have for the first time used a cloning technique to get tailor-made embryonic stem cells to grow in human egg cells.
The development in New York marks a landmark in stem cell research but also represents a potential new flashpoint for opponents.
The researchers were trying to prove it is possible to use a cloning technology called somatic cell nuclear transfer, or SCNT, to make embryonic stem cells that match a patient's DNA.
The achievement is significant because such patient-specific cells potentially can be transplanted to replace damaged cells in people with diabetes and other diseases without rejection by the immune system. This technique could ignite new controversy because some opponents consider it to be cloning.
Stem cells are the body's master cells, the source material for all other cells.
Proponents of embryonic stem cells say they could transform medicine, providing treatments for blindness or severe injuries
Normally, SCNT involves removing genetic material from the nucleus of the host egg cell and replacing it with the nucleus from adult cells, the technique used to clone animals such as Dolly the sheep in 1996.
But scientists so far have failed to get these cells to grow and divide beyond a very early stage in humans and non-human primates.
Scientists in this study, led by Dieter Egli and Scott Noggle at The New York Stem Cell Foundation Laboratory in New York, kept the genetic material from the host egg and simply added the nucleus from the adult cells.
The result falls short because the scientists did not obtain useful cell lines, but they may help explain why other techniques have failed.
"This study shows that the conventional approach to somatic cell nuclear transfer is inefficient in humans," said Professor Mary Herbert of Newcastle University and Newcastle Fertility Centre.
"While this approach does not in itself provide a solution, it takes us a step closer to understanding where the problems lie," Prof Herbert said.
The latest study offers a new approach that may allow scientists to compare different techniques of creating these important and powerful cells.
Embryonic stem cells are made from embryos that are just a few days old, but have been a point of controversy for some religious conservatives, who believe the destruction of any human embryo is wrong.
The goal of these studies is to work out the best ways to create cells that can be used to form any other kind of cell in the body.
Embryonic stem cells have this capability, but these cells cannot be tailored to match a specific patient's DNA, and treatments made from these cells might face rejection from the body, much like transplanted organs.