Interview: Helen Mardon talks stem cells

Professor Helen Mardon is codirector of the Oxford Stem Cell Institute, part of the James Martin 21st Century School at the University of Oxford. I asked her about the potential for stem cell research:

OxSciBlog: What are stem cells and how could they be used in medicine?
Helen Mardon: Stem cells are cells from embryos, umbilical cord blood, or various sites in the adult such as bone marrow that can multiply and also have the capacity to form a range of different cell types in the body – to ‘differentiate’.

The capacity for such differentiation depends on the origin of the stem cells. Stem cells from the embryo have the ability to differentiate into all the different cell types that make up tissues such as cardiac muscle, pancreatic tissue, brain tissue and so on. Stem cells from adult sources, such as the bone marrow, have a more limited capacity.

Stem cell technology thus offers remarkable scope for the development of new cell-based treatments for a diverse range of diseases by allowing tissues in the body to be repaired or regenerated. This could include therapies for heart disease, neurodegenerative diseases such as Alzheimer’s and Parkinson's disease, diabetes, and tissue damage caused by injury.

OSB: What are the main challenges in making stem cell therapies a reality?
HM: There are several major challenges in developing successful stem cell-based therapeutics. For example, stem cells derived from human embryos currently need compounds derived from animal sources to grow, and this needs to be avoided if the cells are to be transplanted into humans. We need to understand exactly how to get stem cells to differentiate or turn into the particular type of cell for a desired type of tissue in the body, whether skin, heart muscle, or pancreatic tissue. Once transplanted into a patient, we want the stem cells to stay where we want them, and not disperse.

Finally, the risk of rejection of the cells by the body's immune system has to be overcome, as is the case for any tissue transplants. This can be done either by generating huge numbers of different stem cell lines to have the best chance of finding a good tissue match, or by manipulating the cells so that the immune system is not triggered.

OSB: How will the work of the new Oxford Stem Cell Institute approach these challenges?
HM: The Oxford Stem Cell Institute has brought together scientists from across the University who are leading world experts in different aspects of stem cell research. Between us, we are addressing these challenges in bringing stem cell therapies to the clinic. The Institute has enabled Oxford scientists with their different backgrounds to collaborate and facilitate a combined effort to take stem cell technology forward.

OSB: How should scientists, governments, and the public respond to ethical dilemmas about the use of stem cells?
HM: There should be open debate and discussion between scientists, governments and the public. It is critical that scientists are transparent about their research and are provided with a forum for conveying their discoveries and the possible implications to the public. Widening of public understanding of stem cell science is essential: an informed public is better placed to make reasoned judgements about ethical dilemmas.

OSB: What landmarks should we expect for stem cell science and medicine in the 21st century?
HM: We should be cautiously optimistic. We should expect to see major advances in stem cell science and its application in medicine as the technology improves. The bringing together of stem cell scientists from different backgrounds, together with continued significant funding opportunities, should drive the science forward toward the use of stem cells in the clinic. We are already seeing adult stem cells being used therapeutically and now it should be possible to begin to exploit the potential of embryonic stem cells.