A positive breakthrough in regenerative medicine has enabled scientists to turn normal skin cells into an embryonic state in mice. If the research is successfully applied to human cells, it will help in converting patient’s cells into specialized tissues that might replace those lost to disease.

Previously, biologists had believed that once fertilized embryos embarked on the developmental path, they could not be manipulated to produce stem cells. New research states differently.

This research could in fact help defuse one of the hottest bioethical controversies of the decade and help reduce restrictions that have caused considerable frustration among biologists and other supporters of research on embryonic stem cells.

If it works, researchers could produce iPS cells (pluripotent, meaning that they could potentially become any of the body’s cells) from patients with conditions such as Parkinson’s disease or diabetes and observe the molecular changes in the cells as they develop. This ‘disease in a dish’ would offer the chance to see how different environmental factors contribute to the condition, and to test the ability of drugs to check disease progression.

Researchers have learned how to make embryonic cells in the laboratory develop into neurons, heart muscle cells and other tissues. In principle, these might be injected into a patient to replace or supplement the cells of the diseased tissue, without fear of immune rejection. The research has also helped in identifying the gene variants for Different diseases: Crohn’s disease, coronary heart disease, hypertension, rheumatoid arthritis and type 1 and 2 diabetes.

In the future it may be possible to test people for combinations of genes to find out their lifetime risk of a disease, which would enable them to modify their lifestyle or undergo screening.

If you let your imagination run wild, you could probably hope to grow human organs for transplantation in the far off future, however, for now the race is on to apply the technique from mice to human cells.

The main pitfall

The most daunting aspect of the research is that two of the four factors used to change the skin cells so efficiently are known to cause cancer. One, in fact, was the first gene discovered to cause cancer in mice. Scientists will have to figure a way to reprogram cells without directly exposing the cell to the cancer-causing effects of these genes. This needs to be totally figured out before even considering using these factors on humans.

Why use stem cells?

Stem cells are unspecialized cells that renew themselves for long periods through cell division. Under certain physiologic or experimental conditions, they can be induced to become cells with special functions such as tissue and muscle cells. They can be developed into beating cells of the heart muscle or the insulin-producing cells of the pancreas.

What are embryonic stem cells?

Embryonic stem cells, as their name suggests, are derived from embryos. Specifically, embryonic stem cells are derived from embryos that develop from eggs that have been fertilized in vitro, in an in vitro fertilization clinic and then donated for research purposes with informed consent of the donors. The embryos from which human embryonic stem cells are derived are typically four or five days old.

So far, the only way to obtain embryonic stem cellsinvolvesdestroying an embryo and to get a genetic match for a patient would mean, in effect, cloning that person all of which raise difficult ethical questions.

As well as having potential ethical difficulties, the ‘cloning’ procedure is technically difficult. It involves obtaining unfertilized eggs, replacing their genetic material with that from an adult cell and then forcing the cell to divide to create an early-stage embryo, from which the stem cells can be harvested. With research will eventually provide an alternative.

If it is indeed possible to take a skin cell from an adult patient and convert it into an embryonic-type cell, that would mean that any patient needing a stem cell-based treatment could, in theory, heal himself. A person’s own skin cells could be converted directly into stem cells without having to collect healthy human eggs or destroy human embryos, steps that until now have been required to obtain embryonic stem cells.

Then again, the introduction of genetically altered genes could result in changes and mutations in humans that might become visible only after centuries. Are we aiming to change the very genetic code of human beings? Alternatively, will governments in the future provide genetic improvements for all, will then we become a race of perfect, equal humans?