It is an unfortunate reality that the therapies often holding the most potential also carry numerous queries regarding their safety. Stem cells are one such topic of concern – their potential to treat disease is exciting but their safety concerns have kept them from being approved for many treatments, despite their initial indications of promising success.
Do the Stem Cells Act as Intended?
A crucial element in assessing stem cell safety is the question: do the cells act as they are intended once transplanted? The unpredictable reality can be that once implanted, stem cells may begin to uncontrollably divide and differentiate into cancer cells, leading to tumour growth. Scientists test the therapies by inducing conditions in laboratory animals, such as a diabetic condition in mice. Laboratory animal models are still, however, far from being perfect predictors of how stem cells will behave once transplanted in humans. The fear of unregulated growth leading to cancerous tumour development is a frightening concept that must be solved before stem cells can reach mainstream status for use to treat the full range of diseases they show potential to help.
Stem Cell Contamination
Stem cell lines used for research are not always ‘pure’ because their exposure to other animal cells to maintain viability results in contamination. Many animal cells contain microscopic microbes and diseases that are undetectable and contaminate human embryonic stem cells used for research. Older stem cell lines that are approved for use are also not as ‘fresh’ and may therefore develop genetic dysfunctions due to their age. As they proliferate, these genetic abnormalities then put the cells at risk for developing into a tumour. Used in a stem cell transplant, the ramifications could potentially be very dangerous.
Regardless of the stem cell source – whether embryonic, adult or cord blood – screening is important to ensure compatibility to the recipient and the specific medical condition being treated. If stem cells were derived from someone with a strong familial history of cardiovascular disease, for example, they would perhaps not be well suited to a recipient who required cardiac heart cells for a damaged heart. In addition, gene analysis and testing for infectious diseases is mandatory to prevent transmission to the recipient.
Biological Activity of Stem Cells
Before stem cells are transplanted, they must possess sufficient biological activity to ensure that they will be successful once implanted. This basically means that scientists need to be certain that the stem cells are healthy and functioning before going through the arduous process of transplantation, often for a person who is extremely ill and can’t afford the time-consuming procedure of a stem cell transplant that simply won’t work.
Clearly, stem cell safety must be scrutinised and assessed throughout the entire treatment or research process. Guidelines and strategies must also be developed to ensure that every aspect of stem cell use – from identification and isolation of stem cells to stem cell transplant – is stringently coordinated. Stem cell lines must be adequately screened for disease and the sources must be examined in depth. If doctors and scientists can establish safe protocols for stem cell use, everyone can benefit from the full potential of the remarkable and possibly life-saving stem cell therapies.