When people think of the word ‘cloning’ they are often hit with frightening images of duplicate human beings being created in somewhat of a mad scientist style experiment. In fact, many members of the public were outraged when “Dolly” the sheep resulted from a cloning experiment in Scotland.
Therapeutic cloning, however, is entirely different and does not involve the creation of a perfectly copied human being. It is reproductive cloning that results in a copy of a specific human being. In therapeutic cloning, no sperm fertilization is involved nor is there implantation into the uterus to create a child.
How is Therapeutic Cloning Performed?
Therapeutic cloning is another phrase for a procedure known as somatic cell nuclear transfer (SCNT). Here’s how it works:
A scientist extracts the nucleus from an egg
The nucleus holds the genetic material for a human or laboratory animal
The scientist then takes a somatic cell, which is any body cell other than an egg or sperm, and also extract the nucleus from this cell
In practical human applications, the somatic cell would be taken from a patient who requires a Stem Cell Transplant to treat a health condition or disease.
The nucleus that is extracted from the somatic cell in the patient is then inserted into the egg, which had its nucleus previously removed
In a very basic sense, it’s a procedure of substitution. The egg now contains the patient’s genetic material, or instructions
It is stimulated to divide and shortly thereafter forms a cluster of cells known as a blastocyst
This blastocyst has both an outer and inner layer of cells and it is the inner layer, called the inner cell mass that is rich in stem cells. The cells in the inner cell mass are isolated and then utilised to create embryonic stem cell lines, which are infused into the patient where they are ideally integrated into the tissues, imparting structure and function as needed.
Benefits of Therapeutic Cloning
A major benefit of therapeutic cloning is that the cells removed are pluripotent. Pluripotent Cells can give rise to all cells in the body with the exception of the embryo. This means that pluripotent cells can potentially treat diseases in any body organ or tissue by replacing damaged and dysfunctional cells. Another distinct advantage to this type of therapy is that the risk of immunological rejection is alleviated because the patient’s own genetic material is used. If a cell line were created with cells from another individual, the patient’s body would be more likely to recognise the foreign proteins and then wage an attack on the transplanted cells. The ultimate consequence would be a rejected stem cell transplant. This is one of the major challenges of organ transplants, alongside the fact that there is a huge shortage of available organs for those who require the procedure. This means that therapeutic cloning has the potential to dramatically reduce the wait times for organ transplants as well as the immunological concerns associated with organ transplant therapy.
Therapeutic cloning is also important to enhancing our understanding of stem cells and how they and other cells develop. This understanding can hopefully lead to new treatments or cures for some of the common diseases affecting people today. In addition, the procedure would allow for scientists to create stem cell therapies that are patient specific and perfectly matched for the patient’s medical condition.
Problems with Therapeutic Cloning
One problem with therapeutic cloning is that many attempts are often required to create a viable egg. The stability of the egg with the infused somatic nucleus is poor and it can require hundreds of attempts before success is attained.
Therapeutic cloning does result in the destruction of an embryo after stem cells are extracted and this destruction has stirred controversy over the morality of the procedure. Some argue that the pros outweigh the cons with regards to treating disease whilst others have likened the destruction to an abortion. Still others state that this doesn’t change the fact the embryo could potentially be a human being and so destruction of the embryo is no different than destruction of a human life.
Because reproductive cloning does utilise SCNT as the primary step, there is also still fear that given our knowledge base to perform reproductive cloning, a scientist may attempt to move beyond therapeutic cloning to creation of a human being.
To this date, no human being has been successfully cloned but the possibility of this occurring is a frightening one not only for the general public and policy makers, but also for most of the ethical scientific field. The majority of scientists are adamantly opposed to reproductive cloning and instead, support therapeutic cloning for Treating Disease. With policies and careful monitoring in place to ensure that therapeutic cloning is used responsibly, we can all benefit from the potential of this procedure to eventually treat, or perhaps one day cure, many diseases.