The hope for new therapies carries a heavy ethical dilemma: embryonic stem cells are obtained from early embryos – and these are destroyed.
Despite many protests, embryonic stem cells are being tested in humans. Four trials have received approval so far, and on October 11, 2010, the first human embryonic cells were injected into the spinal cord.
For some it is the first step in curing common diseases, for others, it is an ethical crime. The emotions beat high, and the factual arguments are quickly out of sight. Pro and con are compiled here (see also advantages of adult stem cells).
1. Embryonic stem cells multiply rapidly
If you want to cure common diseases, you need large amounts of stem cells. Unlike adult cells, embryonic stem cells can be propagated almost indefinitely and raised to any cell number. However, up to now, laboratory culture has been extremely laborious and automated techniques for quasi-industrial production have not yet been developed.
2. Embryonic stem cells are extremely viable
Since every cell of the body originates from embryonic stem cells, theoretically every human organ can be treated with these cells. Slowly growing organs such as the brain contain hardly any adult stem cells; a therapy is currently conceivable only with embryonic stem cells. However, most of the time, the necessary knowledge is lacking to understand the correct development of tissue cells in a test tube.
3. Genetic defects are kept to a minimum
In the genetic make-up of a cell, mutations accumulate over time that can cause cancer in the long term. This is also the case with stem cells, and therefore the younger, the better – and there are no younger cells than embryonic stem cells. However, there is also a problem here: if embryonic stem cells proliferate in the laboratory for a long time, they also change. Therefore, scientists regularly need replenishment of fresh stem cell lines.
1. Embryonic stem cells are rejected by the body
Every foreign cell – including the embryonic stem cell – is recognized and attacked by the immune system. With appropriate drugs, this problem is manageable, but the side effects are sometimes significant. Not unlike heart or kidney transplants, this results in significant loss of quality of life.
2. Embryonic stem cells are difficult to control in the body
The viability of embryonic stem cells also carries a risk: they form a specific form of cancer called teratoma in the body. Before treating a patient, it must, therefore, be ensured that every single stem cell has already developed towards tissue – otherwise the risk of cancer threats will actually not be addressed.
3. Ethical concerns reduce acceptance
Human embryos must be destroyed for these cells, which for many means synonymous with the destruction of human life. And the number of embryos needed could easily skyrocket: presumably you need a wealth of stem cell lines that need to be regularly renewed. What completes the moral dilemma: This massive consumption of embryos would bring considerable profits to the pharmaceutical industry.
On the one hand, embryonic stem cells promise hope for novel therapies in a large number of previously incurable diseases. On the other hand, they create a serious ethical conflict: when they are obtained, an embryo and thus, human life, must be deliberately destroyed.
In order to understand the potential but also the dangers of these special “all-rounder cells”, the advantages and disadvantages of the embryonic stem cells have to be put on the table and discussed. So be sure to think thoroughly about all of the implications that are involved with stem cell research into human embryos.