Researchers successfully convert human skin cells into embryonic stem cells

May 15, 2013
Donor egg held by pipette prior to nuclear extraction. Credit: Oregon Health & Science University

Scientists at Oregon Health & Science University and the Oregon National Primate Research Center (ONPRC) have successfully reprogrammed human skin cells to become embryonic stem cells capable of transforming into any other cell type in the body. It is believed that stem cell therapies hold the promise of replacing cells damaged through injury or illness. Diseases or conditions that might be treated through stem cell therapy include Parkinson's disease, multiple sclerosis, cardiac disease and spinal cord injuries.

The research breakthrough, led by Shoukhrat Mitalipov, Ph.D., a senior scientist at ONPRC, follows previous success in transforming monkey skin cells into embryonic in 2007. This latest research will be published in the journal Cell online May 15 and in print June 6.

The technique used by Drs. Mitalipov, Paula Amato, M.D., and their colleagues in OHSU's Division of Reproductive Endocrinology and Infertility, Department of Obstetrics & Gynecology, is a variation of a commonly used method called somatic cell nuclear transfer, or SCNT. It involves transplanting the nucleus of one cell, containing an individual's DNA, into an egg cell that has had its genetic material removed. The unfertilized egg cell then develops and eventually produces stem cells.

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Human ESCs generated from SCNT embryos were capable of differentiating into a variety of cell and tissue types including contracting heart cells. Credit: Cell, Tachibana et al.

"A thorough examination of the stem cells derived through this technique demonstrated their ability to convert just like normal embryonic stem cells, into several different cell types, including nerve cells, liver cells and heart cells. Furthermore, because these reprogrammed cells can be generated with nuclear genetic material from a patient, there is no concern of transplant rejection," explained Dr. Mitalipov. "While there is much work to be done in developing safe and effective stem cell treatments, we believe this is a significant step forward in developing the cells that could be used in regenerative medicine."

Another noteworthy aspect of this research is that it does not involve the use of fertilized embryos, a topic that has been the source of a significant ethical debate.

Graphic illustrating the cell reprogramming process. Credit: Oregon Health & Science University

The Mitalipov team's success in reprogramming human skin cells came through a series of studies in both human and monkey cells. Previous unsuccessful attempts by several labs showed that human egg cells appear to be more fragile than eggs from other species. Therefore, known reprogramming methods stalled before stem cells were produced.

To solve this problem, the OHSU group studied various alternative approaches first developed in monkey cells and then applied to human cells. Through moving findings between monkey cells and human cells, the researchers were able to develop a successful method.

The key to this success was finding a way to prompt egg cells to stay in a state called "metaphase" during the nuclear transfer process. Metaphase is a stage in the cell's natural division process (meiosis) when genetic material aligns in the middle of the cell before the cell divides. The research team found that chemically maintaining metaphase throughout the transfer process prevented the process from stalling and allowed the cells to develop and produce stem cells.

This is a colony of human ESCs (upper portion) extracted from a blastocyst generated by SCNT Credit: Cell, Tachibana et al.

"This is a remarkable accomplishment by the Mitalipov lab that will fuel the development of stem cell therapies to combat several diseases and conditions for which there are currently no treatments or cures," said Dr. Dan Dorsa, Ph.D., OHSU Vice President for Research. "The achievement also highlights OHSU's deep reproductive expertise across our campuses. A key component to this success was the translation of basic science findings at the OHSU primate center paired with privately funded human cell studies."

One important distinction is that while the method might be considered a technique for cloning stem cells, commonly called therapeutic cloning, the same method would not likely be successful in producing human clones otherwise known as reproductive cloning. Several years of monkey studies that utilize somatic cell nuclear transfer have never successfully produced monkey clones. It is expected that this is also the case with humans. Furthermore, the comparative fragility of human cells as noted during this study, is a significant factor that would likely prevent the development of clones.

"Our research is directed toward generating stem for use in future treatments to combat disease," added Dr. Mitalipov. "While nuclear transfer breakthroughs often lead to a public discussion about the ethics of human cloning, this is not our focus, nor do we believe our findings might be used by others to advance the possibility of human reproductive cloning."

Explore further: Researchers test new gene therapy method in human cells

More information: Cell, Tachibana et al.: "Human embryonic stem cells derived by somatic cell nuclear transfer."

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1 / 5 (4) May 15, 2013
> Several years of monkey studies that utilize somatic cell nuclear transfer have never successfully produced monkey clones.

Neither had they successfully produced embryonic stem cells, had they? Otherwise I don't understand what is new with this article.

Anyway, I'm not much convinced by the paragraph trying to tell me that this is not a step forward human cloning.
1 / 5 (4) May 15, 2013
ARE They Sacred OR Not ? That is the question
1 / 5 (4) May 15, 2013
So, These are ESC-Ncl for Nonclonable and the ESCs that were seriously discussed in the past 2 Decades are ESC-Cl for Clonable.

So, What is that letter N that is missed to avoid the Forbidden????
1 / 5 (3) May 15, 2013
2-Fathered Mice...Only From 2 Males Generation of Viable Male & Female Mice from 2 Fathers alone
1.8 / 5 (5) May 15, 2013
Fantastic news!
1 / 5 (3) May 16, 2013
Why Millennias ago Microscopes could not differentiate between all these varieties of Sht cells?
Breakthrough in cloned embryos poses ethical concerns
1 / 5 (2) May 16, 2013
Something wrong with Magical Lenses. Just as something can be deciphered by Archaeological indicates
Few decades ago started Test Tube Baby Tech itself was an eye-opener.
1 / 5 (2) May 16, 2013
These can't be Raygunn Cells with Allshteimerss
1 / 5 (3) May 16, 2013
Why ShtPrefix was used? Didn't STOP hundreds of Churches Vandalized. Inefficient. ButtGlorified his Personal Barberzhit
1 / 5 (3) May 16, 2013
Enjoy Fun if you missed it because of Age;sr=1-1
1 / 5 (3) May 16, 2013
Many of them Vandalized that too by Shteating 13 yr old BchchGIRL
3 / 5 (2) May 16, 2013
As I've said since day one, stopping embryonic stem cell research is criminal and will only slow it down for when we inevitably won't need embryonic cells because any cell can become a stem cell. As usual,the misguided religious morons do more harm than good.
2.1 / 5 (7) May 18, 2013
Many of them Vandalized that too by Shteating 13 yr old BchchGIRL

Dude, none of what you've posted here makes any sense.
not rated yet May 19, 2013
Oryx and Crake in the making - (a novel by Margarett Atwood) for those who have read it, you will understand what I mean :)

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