With continuing groundbreaking research occurring in the field of genetics, promising results have come from several projects.
Given the worldwide critical shortage of donor organs, scientists are desperately trying to find alternative means of treating patients with organ failure. Recently, Japanese scientists have demonstrated that a functional human liver can be created from stem cells derived from skin and blood. Cells derived from these sources, as opposed to embryos, are known as induced pluripotent stems cells, which can be programmed to grow into any other cell type in the body, such as heart cells or neurons. To make liver cells, scientists combined three different cell types of a human liver—endoderm, mesenchymal, and endothelial. When mixed, the cells grew and began to form liver buds, a group of liver cells that have the potential to grow into a full liver.
Once these buds were transplanted into mice, the buds matured, connecting with the mice’s blood vessels and performing many of the functions of liver cells. Even if a full liver could not be grown from a patient’s cells, a smaller liver could be transplanted to assist a failing liver. Similar approaches are now planned for other organs.
Using induced pluripotent stem cells from skin, researchers have also grown clumps of brain-like tissue. They started with stem cells on a synthetic gel that mimicked connective tissues in the brain, then placed the cells into a centrifugal bath to mix in nutrients and oxygen. Even though the cell clumps lacked blood vessels and only grew to pea size, the resulting tissue can be useful for research on neurological disorders, such as microcephaly, a condition that stunts brain growth and impairs cognitive development.
Another development in the field of genetics is the most promising. Scientists have been able to “edit” the human genome with a heretofore unattainable level of precision. The technique is called Crispr and is so accurate, it may oon be used in gene-therapy trials to treat disorders such as Huntington’s disease. Instead of using current unreliable methods of re-engineering the human genome, scientists will be able to change any part of the DNA molecule, including nucleotides. It may even be used to “correct” the DNA of an embryo to eliminate genetic diseases in families that are prone to particular genetic defects.
The Crispr process developed from a discovery by scientists at the University of California, Berkeley, that bacteria used a specific immune defense against viruses. Using a DNA-cutting enzyme called CAS9, researchers were able to make changes to DNA without unwanted other changes.
If this process is successful, it could lead to the elimination of many types of human diseases, such as HIV and cancer.
Of course, Dr. Moreau might have other ideas for these procedures, but the future of eliminating diseases and genetic disorders looks bright indeed.