Many developments in stem cell research have been made since the promise of human embryonic stem cells was a staple of headlines in the late 1990s and early 2000s. The evidence now indicates that embryonic stem cells, classified as pluripotent because they have the capability of developing into any type of cell within the human body, have failed to keep up with adult multipotent stem cells (which can only differentiate into some cell types).
For example, in June, the Toronto Star reported on a Canadian trial led by researchers from St. Michael’s Hospital and the Ottawa Hospital Research Initiative that is using genetically manipulated stem cells from heart attack survivors’ blood to attempt to repair their own damaged muscle.
The UK Stem Cell Foundation is also funding a study to find whether a stem cell treatment used for horses can assist with the same condition in humans. As reported by the Telegraph, transplanting stem cells from race horses suffering from Achilles tendinopathy (a condition that causes pain in the heel and tendon) into their own damaged Achilles tendons was found to decrease the injury rate by 50 per cent. One horse, Dream Alliance, recovered and won the 2009 Welsh Grand National after receiving the treatment.
According to an article published by the Chicago Tribune in July, researchers may also have found a way to reverse sickle cell anemia in adults by transplanting the patient’s own cells and the cells of a sibling with matching white blood cells. With each patient being followed for an average of three and a half years, 87 per cent of the 30 patients did not see a return in the condition and half of the patients were able to stop taking immunosuppressant drugs, which are usually required with stem cell transplants to stop the body from attacking the donor cells. The findings were published in the Journal of the American Medical Association.
Moreover, scientists have developed a method to create pluripotent stem cells from adult cells without destroying embryos. These cells are called induced pluripotent stem (iPS) cells. “Realistically, (many scientists don’t use) the types of stem cells that are so problematic anymore,” said University of Louisville researcher Scott Whittemore to USA Today. These also have led to various findings. In June, a team of scientists led by M. Valeria Canto-Soler of Johns Hopkins University reported using iPS cells derived from adult skin cells to create miniature human retinas that are able to sense light.
In fact, research presented at the International Society for Stem Cell Research’s 12th annual meeting in Vancouver this June suggests scientists may be able to transform one type of cell into another without using stem cells at all. Lijian Hui from the Shanghai Institute of Biochemistry and Biotechnology presented, “Direct Reprogramming of Fibroblasts to Functional Hepatocyte-like Cells,” which shows that his team of scientists could convert cells from human connective tissue into liver cells.
Part of the difficulty with using embryonic stem cells is that they may cause tumours or be rejected by the patient’s body because they originate from a different human being. Patients undergoing treatment with these cells would need to be given immunosuppressant drugs, which could cause side effects. Adult stem cells do not have the same problems with rejection because they may be taken from the patient’s own body. iPS cells can also be taken from the patient to prevent rejection.
These findings, however, are not stopping scientists from using embryonic stem cells. Dr. George Daley, the director of the stem cell transplant program at Boston Children’s Hospital and past president of the International Society for Stem Cell Research, said that the different kinds of stem cells provide “complementary” approaches. “We’re going to see a whole bunch of things from iPS cells, and I bet we’ll see some from embryonic stem cells. It’s still very early in the field,” he told USA Today.
One recent development in using embryonic stem cells was made by scientists from the University of Connecticut’s Technology Intubation Program, who found that they improved the prognosis of animals suffering from Multiple Sclerosis. The embryonic stem cells performed better than adult bone marrow stem cells, which were found to contain more of a substance that stimulated an immune response from the animals. According to UConn Today (the University of Connecticut’s blog) the scientists said that the embryonic stem cells were easier to use because they could be infinitely multiplied in the lab and were generally of higher quality than adult cells. The findings were published in the online edition of Stem Cell Reports journal.
The first clinical trial using human embryonic stem cell therapy was approved by the FDA in July 2010 after being put on hold for over one year when cysts were found on mice injected with the same types of cells to be used in the study. The stage 1 trial conducted by Geron Corp was to test the efficacy of the therapy on a small number of patients with spinal cord injuries. Four patients began the therapy, but the company cancelled the trial in November 2011 to concentrate on cancer research. Ultimately, Geron Corp’s stem cell assets were purchased by BioTime, which plans to continue the trial.
Other trials have been more successful. Scientists from the Advanced Cell Technology company and the University of California, Los Angeles’ medical school reported in January 2012 in The Lancet that their embryonic stem cell therapy for treating eye disease was safe in humans after injecting two women with stem cells, both of whom reported improvements in their conditions. The MIT Technology Review reported in April 2014 that this treatment for two forms of vision loss (Stargardt’s disease and age-related macular degeneration) will now be tested in more human subjects for efficacy. ACT also announced in February 2013 that it received approval from the Food and Drug Administration for phase I/II clinical trials using the same therapy, this time on patients suffering from severe myopia.
Another avenue of research involves the development of new human embryonic-like stem cell lines using the technique of somatic-cell nuclear transfer (SCNT) – the implantation of donor human genetic material into an egg cell, a form of cloning. An April study in Nature detailed how a team led by Dieter Egli and Mark Sauer used SCNT to create a cell line using genetic material from a diabetic and a healthy adult.
The Washington Times reported in 2013, however, that more private funding is going to non-embryonic stem cell research. Gene Tarne wrote papers for the Charlotte Lozier Institute that showed that the states of California and Maryland have dramatically shifted their funding away from embryonic to ethical stem cell research. For instance, in 2007 when it began operations, the taxpayer-funded California Institute for Regenerative Medicine spent $121 million on human embryonic stem cell research, with no grants going to studies involving adult stem cells. In 2012, however, $50 million was allocated to non-embryonic stem cell research while only $19 million was spent on embryonic stem cells.
Funding by the National Institutes of Health, however, has not gone in that direction. In 2010, a maximum of $165.2 million was allocated to embryonic stem cell research funding, a drastic rise from the $88.1 million spent in 2008. This was due to President Barack Obama’s 2009 executive order abolishing the former policy instituted by George W. Bush which restricted NIH embryonic stem cell research funding only to the stem cell lines that existed in 2001. Funding dropped to $123 million in 2011, but has since gone up to $146.5 in 2012 and $146.1 million in 2013. Funding for non-embryonic stem cell research showed an overall rise up to 2012, when $504 million was spent. This number decreased, however, to $431 million in 2013.
Unlike the U.S., the Canadian government does not provide aggregate data about money spent on embryonic and non-embryonic stem cell research. A search in the Canadian Research Information System found a total of $6,090,398 in funding allocated in fiscal year 2013-2014 towards projects with the key word “embryonic stem cell,” with most of the funding provided by the Canadian Institutes of Health Research and the rest by the Canadian Cancer Society. Searching “induced pluripotent stem cell” gave a total of $2,694,594 and “adult stem cell” resulted in the sum of $1,923,824. More money was spent on embryonic stem cell research from 2008 to 2012 (over $7 million each fiscal year). Overall, money for iPS and adult stem cell research seems to be on the rise but is still behind ESCR.
There are serious limitations, however, in using this database for an accurate estimate of funding, since the inclusion of the key words in the project description does not necessarily indicate that these cell types were used. Some of the studies also use more than one type of stem cell. For instance, many studies use both embryonic and non-embryonic stem cells, so much of the funding listed as going to ethical stem cells also includes projects which use both non-embryonic and embryonic cells. As well, some of the projects only involve research on animal cells.
Even as non-embryonic stem cells prove to be more effective than their unethical counterparts, however, it is unlikely that scientists will stop using embryos for research. “Each cell type has different uses for different purposes,” said Bernard Siegel, chairman of the ninth annual World Stem Cell Summit. “We need them all.”
Jim Hughes, national president of Campaign Life Coalition, told The Interim that CLC fought against ESCR because it is immoral as it requires the destruction of embryonic human beings. “Whether or not embryonic stem cells work is ultimately irrelevant to whether it should be allowed: it is wrong to destroy human life.”
