Despite the enormous therapeutic potential for stem cells to treat a vast array of serious diseases there are still concerns about potentially dangerous results. Scientists are excited about the possibilities of saving lives and reducing morbidity from disease but at the same time, there are fears regarding unexpected results and effects from stem cell usage. With recent technologies having triggered a major increase in stem cell treatments, the concept of stem cell therapies is no longer such a foreign one.
Both scientists and the public shouldn’t, however, simply accept these technologies without first contemplating their impact on society. Although the benefits of stem cell therapies are enormous, risks must also be considered.
Passing on Viruses
A possible concern is that stem cell therapy could pass on viruses or other microscopic agents that cause disease. Patients who are receiving transplants often take strong drugs that essentially ‘wipe out’ their immune system. This is to reduce the chances of their body rejecting a transplant. The flip side is that if any viruses are present in the transplanted stem cells, a patient’s immune system is completely vulnerable to disease.
Diseases From Other Animals
Animal sources may be used to provide nutrients to stem cells that are being cultivated in the laboratory. These sources could contain various diseases that may then be passed on to humans receiving cell-based therapies. A concern is that screening is currently insufficient to detect known diseases that may be present. Also, there may be diseases we are still yet unaware of that could be passed on to humans.
One concern with embryonic stem cells is related to the very quality that makes them so useful and versatile. Embryonic stem cells are ‘young’ cells and tend to grow quickly; the fast growth must, however, be carefully guided by scientists. These stem cells need to be cultivated and directed into specialised cells with great care because the potential for remaining stem cells to grow uncontrolled could be disastrous. These uncontrolled cells could eventually form tumours.
The possibility of transplanted stem cells differentiating into the wrong type of tissue is yet another concern regarding therapeutic stem cell use. Once stem cells are cultivated in a laboratory, researchers need to control and direct their growth into desired tissue cells. Scientists are attempting to overcome this problem by inducing partial stem cell differentiation prior to transplanting it into a patient. This would hopefully limit the capacity of the cells to differentiate into undesired tissue types once implanted.
At present, scientists still know very little about how stem cell differentiation is controlled. One such example occurred in 2001, when researchers claimed to have created cells that produced insulin. This claim was later found to be incorrect because cells had merely absorbed insulin from the environment, rather than producing it. Further research will ideally explain how cell signals operate to trigger cell differentiation.