Thursday May 16 2013
Stem cells can potentially develop into every type of human cell
"Human embryonic stem cells created from adult tissue for first time," The Guardian reports, while the Daily Mail's front page leads with the somewhat fanciful warning that new research raises the "spectre of cloned babies".
These headlines are based on newly published research into the use of a technique known as somatic cell nuclear transfer (SCNT) as part of embryonic stem cell research. It should be noted that no babies were born as a result of this research, and the researchers had no intention of producing a live cloned human being.
SCNT involves taking donated egg cells from women and removing their genetic material. These are then fused with human cells – in this case skin cells – and the fused cell begins behaving in a similar way to an embryo by producing human stem cells.
This research is the first time the technique has been successful using human cells.
When these stem cells were tested, researchers found that the cells were able to develop into other types of cells in a manner similar to that seen in stem cells derived directly from embryos.
The researchers say that this could have exciting implications. The technique could potentially be used to take skin cells from a patient to create "personalised" stem cells. The resulting stem cells could then possibly be used to repair damaged tissue, or even treat genetic conditions.
However, there remain ethical concerns over the implications of using SCNT to develop stem cells. These concerns, as well as scientific and financial considerations, will need to be taken into account as this field continues to develop.
Where did the story come from?
The study was carried out by researchers from Oregon Health and Science University (OHSU) and Boston University School of Medicine in the US, as well as Mahidol University in Thailand. It was funded by OHSU, the Leducq Foundation and the US National Institutes of Health, and was published in the peer-reviewed journal, Cell.
Media coverage of this study was as varied as people's feelings are about stem cell research. It ran from the medically hopeful headline of The Independent ("Human cloning breakthrough raises hopes for treatment of Parkinson's and heart disease"), to a straight-to-the-facts headline from The Guardian ("Human embryonic stem cell created from adult tissue for first time"), to fear and controversy from the Daily Mail ("New spectre of cloned babies: Scientists create embryos in lab that 'could grow to full term'").
Despite its headline and further warnings of "designer babies", the Daily Mail does provide a quite useful figure outlining the process the scientists used in the research.
What kind of research was this?
This was a laboratory study that aimed to produce embryonic stem cells from adult skin cells. Embryonic stem cells are unique in that they are able to develop (or differentiate) into other types of cells. Because of this, it is thought that they could play a critical role in the treatment of a wide variety of diseases.
Researchers have been looking into ways of using a patient's own cells to create embryonic stem cells, as this would ensure that the genetic material in any cells used therapeutically would match the patient's DNA. In theory, this should prevent the body from rejecting the cell.
The researchers report that previous attempts to produce embryonic stem cells using this technique have failed, as the cells stopped dividing before they reached an advanced enough stage. During their experiments, researchers identified two reasons for this inability to sufficiently grow the cells and developed techniques to overcome these limiting factors.
Laboratory studies are necessary for developing techniques and procedures that may one day lead to new medical therapies.
This study will no doubt be very exciting for researchers working with stem cells, but we're still a long way from the findings of this study being translated into new treatments for conditions such as Parkinson's disease or heart disease.
What did the research involve?
The researchers used a technique called somatic cell nuclear transfer (SCNT) to transfer genetic material from adult human skin cells into a human egg cell in order to produce embryonic stem cells. SCNT has been used to clone animals before, and is thought to have potential applications in the study and treatment of human diseases.
SCNT involved taking the nucleus (the part of a cell containing most of the genetic information) from a person's skin cells, inserting its cells into a donor's unfertilised egg cell that had its nucleus removed. The skin cell nucleus was then fused with the donor egg cell. Once this happened, the person's genetic material was in a vehicle that was theoretically able to divide.
Researchers then optimised methods to prompt the egg cell to start and continue to divide using electricity and chemical compounds, including caffeine.
Once this cell division yielded approximately 150 cells – a stage called a blastocyst – researchers were able to isolate the embryonic stem cells. The researchers then tested these stem cells to see if their genetic material retained any traces of the genetic material from donor egg cell's nucleus. They also tested whether or not the embryonic stem cells were able to develop into other types of cells.
What were the basic results?
The researchers were able to use SCNT to generate human embryonic stem cells. These cells were found to match the nuclear genetic material of the person's skin cells, and did not contain any trace of the donor egg's nuclear genetic material.
The embryonic stem cells were able to develop into several different types of cells, including heart cells. They were also found to express genes similar to those expressed by embryonic stem cell lines derived following IVF procedures, which the researchers referred to as "genuine" embryonic stem cells.
How did the researchers interpret the results?
The researchers say that this study represents the first successful attempt at generating human embryonic stem cells following somatic cell nuclear transfer.
They say that the observed ability for these embryonic stem cells to develop into heart cells demonstrates their potential use in regenerative medicine.
This research represents the first time that human embryonic stem cells have been developed using the "cloning technique" known as somatic cell nuclear transfer (SCNT).
It is important to note that this study did not attempt to clone a human being by creating a baby in a lab. It is unclear at this point whether the cells in this study would continue to stably divide in a manner sufficient for an embryo to develop to full-term.
While this study is certainly a breakthrough for researchers in the field, its findings are unlikely to translate quickly into regenerative medicine or other medical therapies.
There are some scientific limitations to the approach, including the fact that only a fraction of the fused cells were able to divide sufficiently to reach the blastocyst stage and, of those that did, not all were able to generate stable embryonic stem cell lines.
It is also worth considering that donated egg cells from women are required before SCNT can be carried out, potentially limiting the ability of scientists to generate stem cells on an "industrial" basis.
SCNT does not represent the only approach to embryonic stem cell development. Researchers around the world continue to investigate several methods for developing and using stem cells. It is not immediately clear how the current research will fit into this field, or whether it will trigger a major shift in stem cell research.
In addition to these scientific hurdles, there are ethical and financial considerations that will likely need to be addressed.
Despite these issues, this research does represent a breakthrough in the use of SCNT in the stem cell research field and has implications for disease research.
What the study emphatically does not represent is an impending expansion into cloning babies.
Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter.