Scientists use cloning to make human stem cells

CHICAGO, (Reuters) – U.S. scientists for the first  time have used a cloning technique to get tailor-made embryonic  stem cells to grow in unfertilized human egg cells, a landmark  finding and a potential new flashpoint for opponents of stem  cell research.
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, published on Wednesday in the journal  Nature, 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, which they fiercely  oppose.
“This paper will be seen as significant both by those who  are trying to use SCNT to produce human patient-specific  embryonic stem cell lines and by those who oppose human  ‘cloning’ experiments,” said Professor Robin Lovell-Badge, a  division head at Britain’s National Institute for Medical  Research.
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, juvenile diabetes 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.
“Rather surprisingly — as this means that they are  creating an embryo with too many copies of each chromosome —  these constructs developed well and efficiently to the  blastocyst stage (the stage just before implantation, where the  embryo is about 80 to 100 cells),” Lovell-Badge said in a  statement.
She said 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.