The Stem Cell Race

by Jessica Collins

Recent headlines featuring Peyton Manning and Kobe Bryant seeking medical attention outside the U.S. have caught the attention of sports enthusiasts and news followers alike. They are just two of the many individuals who have sought out stem cells in hopes of getting back in the game. Lately, there has been a surge of professional athletes leaving the country in search of stem cell therapies to treat their injuries. This fad, known as “medical tourism,” is becoming more and more popular as word spreads of the wide range of injuries and diseases being treated in other countries with stem cells. This is a rapidly growing industry in many countries, like Mexico, Costa Rica, Ukraine, China and India. In the small country of Costa Rica alone, medical tourism made revenues of $60 million in 2008.

Various groups within the U.S. offer services to find stem cell clinics in one of these countries that will provide the desired treatment for clients. Diseases currently being treated abroad with stem cells include diabetes mellitus, multiple sclerosis, Parkinson’s disease, Duchenne muscular dystrophy and cancer, as well as a wide range of injuries. Why are not  these treatments offered in the U.S.? Because they have not yet been approved by the Food and Drug Administration (FDA). 

For the FDA to approve a course of treatment, the method must first undergo multi-stage human clinical trials that prove that the treatment positively influences the patient’s disease or injury. Currently in the U.S., hematopoietic stem cells from bone marrow and umbilical cords are being used to treat patients with leukemia and lymphoma. While there is a lot of research going on both in the U.S. and other countries using adult stem cells, only a few companies in the country have been approved to do human trials using embryonic stem cells – most notably, Geron and Advanced Cell Technology (ACT).

Geron received FDA approval to begin trials on patients suffering from spinal cord injuries in 2009. In 2010, ACT announced that the FDA had approved human trials for macular dystrophy treatment. Compared to other countries, such as Ukraine, El Salvador, and China the U.S. seems to be lagging in the field of embryonic stem cell research and therapy.

While there are many reasons for this slow development, politics has been a key issue. During the Bush administration, federal funding was limited to specific, pre-existing embryonic stem cell lines. When President Obama came into office, the cuts that the Bush administration put on embryonic stem cell research were repealed. This change in policy has opened a new door for many scientists who could not previously explore the capacities of embryonic stem cells.

In a recently published paper, a team of scientists from the Texas Biomedical Institute, with help from faculty at the University of Pittsburgh, completely repaired a segment of baboon artery in just two weeks, using stem cells. The research group made this repair by differentiating baboon embryonic stem cells into endothelial cells specific to the vasculature, called endothelial progenitor cells. A damaged section of baboon femoral artery was excised and the inner cell layer of the artery was removed. The progenitor cells were then added and bathed with a growth media in a bioreactor, to allow the cells to form a new cell lining inside the artery.

The medical implications of this research are vast. From this project alone, we can see that the future may hold new treatment options for patients with vascular damage or who suffer from heart attacks and other circulatory problems. The findings also suggest that stem cells could be used to repair multiple areas of the body, so long as the embryonic stem cells were differentiated appropriately. These cells could be used to repair a variety of damages, like those associated with spinal cord injuries, neurodegenerative diseases, diabetes, eye disease or arthritis. There are potential therapeutic uses for embryonic stem cells in individuals with heart or lung damage, or even for burn victims that need their bodies to repair damaged skin cells.

The pluripotent potential of embryonic stem cells might even lead to organ generation if the cells are differentiated correctly. When asked about the importance of his research, Dr. Qiang Shi of the Texas Biomedical Research Institute responded, “The only problem we have in the future is that you are getting too old, you want to survive, and you want to lead a better life. Stem cells are the agent that can rejuvenate your body.”

While this research is regarded as highly valuable to the field of medicine, the issues associated with embryonic stem cell research are difficult to surmount. Getting FDA approval as well as financing for this type of research is no easy task. A common ethical debate is whether embryonic stem cells should be understood as life or as scientific property. Does life begin at conception, or after fetal development? Because of this argument, many U.S. citizens do not approve of using human embryonic stem cells for research, causing the flow of money, both public and private, to avoid this field. The lack of successful evidence involving embryonic stem cells is also inhibiting public support.

There is hope that with more research, more trials will be approved and eventually translated into treatment options for injuries and diseases. According to Shi, the key is to do research in a primate model because the findings are most accurate for translational medicine. Mice and rabbits, commonly used animals in research, are smaller in size and have shorter life-spans – and thus different cellular metabolic properties. Since baboons and monkeys are more anatomically similar to humans than any other animal, they are the ideal model for medical research. While this is a huge issue with animal rights groups, this is the quickest path to take to translate laboratory results into health care practices, particularly with regard to stem cell treatments. As Shi puts it, “Stem cells are fantastic. Stem cells are the future. Stem cells are the next generation of medicine.”