October 3, 2012
Study Shows Epigenetics Of Adult Stem Cells Influences Organ Creation
Alan McStravick for redOrbit.com - Your Universe Online
Ask a handful of people about their thoughts and feelings on the use of stem cells for research and therapeutic means and you will find that they each have strong and varying positions on the topic. Outside the scientific community, however, little is known about this highly complex field of research.
The politicization of stem cell research accompanied the 1998 discovery that embryonic stem cells, the building blocks of organ, tissue, bone and brain cells, could be extracted for study and medical use. In 2001, with an order to limit the ℠lines´ of stem cell research to those already in possession of the scientific community, President George W. Bush largely hampered the development of this field in the United States by limiting government funding for stem cell research. Adult stem cells, or somatic stem cells, were unaffected by this order, but the prevailing wisdom of the genetic community was that adult stem cells were not as dynamic and couldn´t be used in the same way as their embryonic cousins.
With a report published Monday in the American Journal of Pathology, that truth no longer seems to be the case. A team led by Manel Esteller, director of the Cancer Epigenetics and Biology Program in the Bellvitge Biomedical Research Institute (IDIBELL), was able to identify epigenetic changes that occur in the somatic stem cells to generate different body tissues.
The use of somatic or adult stem cells had been a regular occurrence since their discovery in the 1950´s. It was then that researchers found that bone marrow contains two different kinds of stem cells. The first, called hematopoietic stem cells, form all the types of blood cells in the body. The second, known as bone marrow stromal stem cells, were discovered only a few years later and are effective in the generation of bone, cartilage, fat and fibrous connective tissues.
One thing that has been understood is that the genome of each cell in the human body is identical. This is true regardless of their appearance and function. It is for this reason that certain anomalies, such as cancer, are seemingly incomprehensible as they are unable to be explained by the genome of the host. To better understand such complex genetic deviations, something more is required.
Researchers in this current study offer an explanation via analogy. Epigenetics is defined as “the inheritance of DNA activity that does not depend on the strict sequence of it.” According to the team, if genetics is the alphabet, spelling would be the epigenetics, referring to chemical changes in our genetic material as well as the proteins that regulate and control their activity.
We now know that somatic stem cells have enormous potential to regenerate damaged organs. By investigating how to use them more effectively in different types of therapies, the research team postulates that it will become easier to steer clear of any sticky ethical complications that might arise from working with embryonic stem cells.
In this study, the team was able to isolate somatic stem cells from body fat, allowing them to transform them into muscle and bone cells. Through their study, they observed the resemblance of the cells created in the laboratory to those of the host individual. They were also able to determine that the cells were biologically secure enough that they might be implanted into waiting patients. Overall, the study was able to show that the epigenome of the cells obtained and maintained in culture closely resembled skeletal and muscle cells that are spontaneously present in nature, though not completely identical.
The most startling discovery of the study was that the muscle and bone cells that were created in the laboratory were devoid of the tumor epigenome. This showed they were safe, from a biological perspective, for future medical use. Esteller stated that the research, “demonstrates the usefulness of epigenetics in determining the degree of maturity and biosecurity of differentiated tissues used in regenerative medicine against different diseases.”