In this blog post, we’ll take a look at the arguments for and against the use of embryonic stem cells, and find out why I’m against the use of embryonic stem cells!

The concept of embryonic stem cells and the current state of research

After a brief lull, interest in embryonic stem cells is growing again, thanks to a recent study that used embryonic stem cells to restore sight to blind patients. According to the medical journal The Lancet, 18 patients with dry age-related macular degeneration (AMD), a retinal disease that causes blindness in the elderly, and 18 patients with Stargardt macular dystrophy, a rare retinal disease, were successfully transplanted with retinal pigment epithelial cells made from embryonic stem cells to restore their vision. The 18 patients in the clinical trial were blind or had reduced vision due to damaged retinal pigment epithelial cells, but after the transplant, 13 of them regained or improved their vision due to increased pigment cells. As you can see, embryonic stem cells can play a big role in treating rare or incurable diseases. But what are embryonic stem cells and how can they be obtained?
As the name suggests, embryonic stem cells are a type of stem cell. Stem cells are cells that can differentiate into any tissue. There are three types of stem cells: embryonic stem cells, adult stem cells, and pluripotent induced stem cells. Embryonic stem cells are derived from a fertilized egg, which is the result of a male gamete (sperm) meeting a female gamete (egg), and can be derived from a blastocyst embryo just before implantation or from a fetus that has miscarried between 8 and 12 weeks of gestation. Embryonic stem cells are cells that are actively dividing but have not yet differentiated, and can theoretically differentiate into any cell in the human body. Because of their ability to differentiate into any cell, embryonic stem cells can be used for direct therapies, as mentioned above, as well as for drug discovery and research into the development of embryos. But are these the only advantages of embryonic stem cells?

Arguments in favor of embryonic stem cells

Before we get into the arguments against embryonic stem cells, let’s take a look at the arguments in favor of them. First, proponents of embryonic stem cells argue that embryos up to 14 days after fertilization are not human and are just clumps of cells. However, this is a deliberate attempt to sidestep the ethical issues that arise because embryonic stem cells are derived from fertilized eggs. A fertilized egg, which is created when an egg and sperm meet and fertilize, becomes an embryo, fetus, or newborn child through cell division. In other words, there is no intrinsic change between a fertilized egg and an embryo, fetus, or newborn, only a change in form. Therefore, there is no difference in dignity between them. Furthermore, human dignity does not lie in the distinctiveness of a human form, but in human life itself, so the proponents’ argument is not correct.
The second argument is that embryo testing helps cure incurable diseases. Human life is very precious, so saving a dying life is also precious. For this reason, proponents support embryo testing. However, saving a dying life cannot be done at the expense of another human life, or at the expense of something that is ethically and morally wrong. An embryo can be considered a human life, so using embryos to cure an incurable disease is ultimately sacrificing one life to save another. There is no prioritization of value in human life, so sacrificing one human being for another cannot be justified. Of course, research to cure incurable diseases should continue. However, if this can be done through other means than the ethically problematic use of embryonic stem cells, then it makes sense to pursue this field more vigorously. I will return to these other options later.
The third argument is that embryo testing is good for economic development. The argument for allowing embryo testing for economic reasons is tantamount to giving up human dignity in favor of material wealth. If a country allows embryo testing for this reason, it means that the country is prioritizing economics over ethics and morality, creating an unethical society. If this materialistic view of human beings as clusters of cells becomes widespread, the wealth gained from it will corrupt society and cause more harm in the long run. Therefore, these arguments are not valid reasons in favor of embryo testing. Next, let’s look at the arguments against embryonic stem cell research.

Arguments against embryonic stem cells

The first and most important argument is the ethical one we mentioned earlier. Proponents of embryo research try to get around the ethical issues by defining an embryo as a clump of cells and defining when it becomes a human being in their favor. They also define embryonic stem cells obtained by removing the outer layer from the blastocyst as pluripotent, which means that they do not have totipotency, but only the ability to differentiate into various organs. In other words, embryonic stem cells cannot implant in the endometrium because they do not have an outer layer, and therefore do not have the ability to develop into an individual, so they are just cells. However, the work of Dr. James Thompson, who first isolated embryonic stem cells, has shown that embryonic stem cells that have been stripped of their envelope can regain their envelope if given the right culture conditions. Connecting this to the previous discussion, we can say that an embryo is essentially a form of human being, and embryonic stem cells are also a form of human being because they have the ability to develop into an individual again if given the right environment. Therefore, it is not correct to view embryonic stem cells as a clump of cells and cannot escape the ethical point that human life is being used for convenience.
Secondly, embryonic stem cell research is not the only way to treat incurable diseases. As the previous discussion shows, stem cells include not only embryonic stem cells, but also adult stem cells and induced pluripotent stem cells. First, let’s look at how adult stem cells are used. Adult stem cells are derived from a mother’s umbilical cord blood or an adult’s bone marrow, and are primitive cells that are just about to differentiate into the cells that make up our bodies, such as bone, liver, muscle, nerve, and blood cells. They have the disadvantage that they are difficult to differentiate into cells that are different from their original nature and are difficult to mass produce outside of the body, but because they are your own stem cells, they do not cause immune rejection. In addition, adult stem cells have the advantage that their proliferation is regulated according to the physiological environment of the body, so teratomas do not occur due to rapid proliferation like embryonic stem cells. In other words, due to the controllability of proliferation and the stability of directional expression, adult stem cells are actually used for neurological diseases such as Parkinson’s disease, cardiovascular and endocrine diseases, bone and joint diseases, etc.
Next, induced pluripotent stem cells are somatic cells that have had a few genes and proteins inserted into them, returning them to an early embryonic stage with the same characteristics as embryonic stem cells. Induced pluripotent stem cells are cells that have the advantages of embryonic stem cells without the use of an embryo, and they have the limitless differentiation capabilities of embryonic stem cells. In recent years, the development of stem cell therapies using induced pluripotent stem cells has been actively studied, and in 2007, a study using Parkinson’s disease model rats was reported in the British journal Nature, which showed that the motor function of Parkinson’s disease model rats returned to normal by differentiating dopamine-secreting neurons with induced pluripotent stem cells. In addition, since induced pluripotent stem cells are made using one’s own body cells, there is no immune rejection and it is easy to find a body cell donor. Since adult stem cells and induced pluripotent stem cells are highly effective in treating incurable diseases, it is more appropriate to conduct research on incurable diseases using other stem cells that do not have ethical problems.
Third, embryonic stem cells are not stable enough for actual treatment. In 2014, for the first time in Asia, a clinical trial using embryonic stem cells was approved in Japan. In September 2013, a team of researchers at the National Institute of Science and Technology succeeded in creating retinal cells from human embryonic stem cells using a supercomputer, and in July 2014, the Japanese Ministry of Health, Labor and Welfare approved a clinical trial plan to transplant retinal cells made from embryonic stem cells into patients with age-related macular degeneration. However, the trial was abruptly halted in March 2015. The researchers said they stopped the trial because they did not see any side effects after treating the patients with induced pluripotent stem cells from somatic cells taken from the patients, so they decided it was not necessary to use embryonic stem cells. Clinical trials using embryonic stem cells are challenging because of the potential for side effects such as rejection and teratomas. In contrast, induced pluripotent stem cells have been shown to have fewer side effects, making embryonic stem cells less stable for real-world treatment.
Finally, there are many side effects and risks associated with the egg retrieval process. Embryonic stem cells are obtained from fertilized eggs obtained through an in vitro fertilization procedure. In the IVF process, women are given hyperovulation inducing drugs to obtain 10 or more eggs. At this point, women may experience abdominal bloating, nausea, and vomiting as their ovaries enlarge, and long-term use of ovulation inducers can lead to ovarian hyperstimulation syndrome and ovarian cancer. Egg retrieval requires general anesthesia, which can have life-threatening side effects such as respiratory distress and heart attack. Therefore, it is inappropriate to use such a risky method to obtain embryonic stem cells.
So far, we’ve covered the concept of embryonic stem cells and the arguments for and against them. They are ethically problematic because they come from embryos, they are not the only way to cure incurable diseases, and they are not very stable. There are also many side effects and risks that women face during the egg retrieval process. Therefore, experiments with embryonic stem cells should be stopped.