New stem cell technique could make human cloning easier

Los Angeles, Calif., Apr 15, 2008 / 02:47 am

The same newly-developed technique that ethically produces stem cells for research can also be used to lower the technical barriers to human cloning, the Independent is reporting.

With the new technique, cloning procedures are now so simple and efficient that some fear maverick researchers will soon attempt to clone humans.

Last year, researchers announced that they had genetically reprogrammed adult skin cells to return the cells to an embryonic-like state.  The reprogrammed cells, called induced pluripotent stem cells (iPS cells), are believed to have great potential for health treatments.  The technique by which iPS cells are created is thought to sidestep ethical and practical issues surrounding human embryonic stem cell research, in which human embryos are created and destroyed.

Scientists have now used the same iPS cell creation procedure to create baby mice from the skin cells of adult animals.  Adult mouse skin cells, reprogrammed to become iPS cells, were inserted into early embryos produced by in-vitro fertilization (IVF).  Some of the offspring were partial clones, known as chimeras, sharing the genetic material of both the original embryo and the inserted iPS cells.  Other offspring were full clones, like Dolly the Sheep, completely matching the genetic make-up of the donor cell.

Some fear the technique will be used by IVF doctors to help infertile couples who want to have their own biological children.

“It's unethical and unsafe, but someone may be doing it today," said Robert Lanza, chief scientific officer of American biotechnology company Advanced Cell Technology, a pioneering company in stem cell and stem cell reprogramming research.

“Cloning isn't here now, but with this new technique we have the technology that can actually produce a child. If this was applied to humans it would be enormously important and troublesome.”

Though the technology for such cloning does not yet exist, Lanza said, “with this breakthrough we now have a working technology whereby anyone, young or old, fertile or infertile, straight or gay can pass on their genes to a child by using just a few skin cells."

The experiments on mice have demonstrated the possibility of taking an adult human skin cell, reprogramming it to induce an embryonic-like state, and then inserting the cell into a human embryo.  The resulting embryo would then be either a full clone of the adult or a chimera sharing its original genetic makeup and that of the adult cell’s donor.

Chimeras do occur naturally when two embryos fuse together early in life.  Dr. Lanza said there was no reason to believe a human chimera created by the technique would be unhealthy.

The research on mice proved that fully cloned offspring can be produced with the technique.  Researchers used a defective “tetraploid” mouse embryo with four sets of chromosomes instead of the normal two.  The embryo only developed into the placenta of the fetus.  The embryo was injected with an adult animal’s reprogrammed skin cell, developing from a single cell to become a full clone of the adult.

Dr. Lanza said the technique could easily produce cloned or chimeric babies.

“At this point there are no laws or regulations for this kind of thing and the bizarre thing is that the Catholic Church and other traditional stem-cell opponents think this technology is great when in reality it could in the end become one of their biggest nightmares," Lanza said. "It is quite possible that the real legacy of this whole new programming technology is that it will be introducing the era of designer babies.

"So for instance if we had a few skin cells from Albert Einstein, or anyone else in the world, you could have a child that is say 10 per cent or 70 per cent Albert Einstein by just injecting a few of their cells into an embryo," he said, according to the Independent.

No scientists working on iPS cells plan to use them for reproductive medicine.  They aim to produce stem cells for treatments of conditions like Parkinson’s, Alzheimer’s, and stroke.