Stem Cell Research: Ethics, Cloning, and Medical Uses

Introduction to Stem Cell Research and Federal Policy

This paper considers the current moral discourse on the issue of stem cells while also examining the basics and foundation of stem cell biology. It also explores how these cells can be utilized to conduct studies in cloning.

The pertinent issue on the floor of the U.S. Congress in deliberations on stem cell studies involving humans is how to handle embryonic stem cell research (ESR) — a kind of research that may generate crucial lifesaving therapies but that demands the destruction of embryos. Present national government regulations and policy documents tackle this issue primarily through limits on federal funding allocated to ESR (Aylesworth, 2010). The U.S. Department of Health and Human Services is not permitted to spend any money on creating human embryos for studies in which the embryos will be damaged, discarded, or intentionally exposed to risk of injury or worse, under the Dickey Amendment. Specifically, this congressional amendment prevents the use of HHS funds to create new embryonic stem cell lines — which may entail the destruction of embryos — but it does not prevent research using already-established lines (Aylesworth, 2010).

Stem cell science is among the most remarkable innovations in the field of medicine in over a hundred years. Medical therapies founded on the use of stem cells have great potential for treating many difficult-to-treat ailments and injuries. At the same time, the body's own inherent stem cell populations are important and deserve consideration as well. They are largely unnoticed but play a significant part in our daily well-being, aging, and reproduction (Knoepfler, 2013).

The Role of Stem Cells in the Human Body

There are millions of inherent stem cells in the human body for particular tissues or organs. This sounds like a large number until one remembers that the human body is composed of trillions of cells. Each day, stem cells play an important role as the body's minute defense system, having an enormous impact. This is what fascinates researchers in the transplant branch of stem cell studies (Knoepfler, 2013).

In each tissue of the body, stem cells are continuously surveying, ready to spring into action when a person is injured or diseased. They activate immediately upon injury and carry out their function like a battalion of tiny physicians working from within. They are the body's defenses against disease. The way these inherent stem cells operate helps researchers envision how, when transplanted into patients, stem cells will behave. This is an emerging area of medicine. It is expected that stem cells transplanted into a recipient patient will function similarly to the body's own inherent stem cells, or perhaps even more effectively (Knoepfler, 2013).

Cloning and Stem Cells

The sheep named "Dolly" was created by transferring a nucleus from a differentiated udder cell into the cytoplasm of an egg cell from which the nucleus had been removed. The cell therefore had to be reprogrammed from an initial state matching that of an ordinary udder cell back to an embryonic state. In this embryonic state, most genes specific to a particular tissue are deactivated while those associated with pluripotency are activated. This reprogramming process is highly inefficient and prone to error. It most likely occurs in a stochastic manner, such that only a small percentage of chimeric cells ever develop to the point that allows embryonic development to proceed. Over the preceding six years, no methods to improve this reprogramming stage had been identified. What is clear, however, is that certain cell types respond more efficiently than others (Voneky and Wolfrum, 2004).

For instance, cloning via nuclear transfer has been shown to be at least 20 times more effective when performed using embryonic cells than adult cells. This is logical, because most of the pluripotent genes in embryonic cells are already activated and tissue-specific genes are already deactivated, requiring less reprogramming compared to adult cells. It has been suggested — though not proven — that the overall genetic makeup of adult stem cells may resemble that of embryonic cell types. Adult stem cells have since been identified in the most specialized adult cell forms, and they may therefore be more amenable to reprogramming than other adult cells. A genetic imprint is a specific form of reversible programming of a particular cell. Unlike genetic modifications that result in mutations, these reversible alterations are called epigenetic modifications (Voneky and Wolfrum, 2004).

In theory, all of the above is applicable to humans. Cloning of a human via nuclear transfer methods should therefore be considered technically possible. However, beyond the many moral objections discussed in this paper, the documented errors and inefficiencies of the process argue persuasively against any such attempt (Voneky and Wolfrum, 2004). Plans to attempt human cloning despite these concerns led to claims that cloned babies had already been born — claims that generated extraordinary public outcry. Those declarations have since been found to be false.

Nuclear transfer technologies have also been proposed for use in cell therapy. In this application, cloned embryos would not be transferred into a uterus but would instead be used to create autologous stem cell lines, which would then be developed into functional cells for therapeutic use. This approach is known as therapeutic cloning, which is distinct from reproductive cloning — the cloning of whole individual organisms. Therapeutic cloning is often discussed in relation to the problem of immune rejection of allogenic transplants. Embryonic stem cell lines sourced from a donor other than the patient are recognized by the recipient's immune system as foreign and are rejected unless the patient receives immunosuppressants. By contrast, embryonic stem cells developed via nuclear transfer using the patient's own cells are genetically identical to that patient, thereby eliminating the risk of immunological rejection (Voneky and Wolfrum, 2004).