Stem Cell Therapy - The Future

Jan 4, 2011
Sebanti Ghosh

Pluripotent stems cells from developing embryos - Original work by Mike Jones for Wikipedia

Discoveries in stem cell therapy are making waves worldwide. What it does it mean for the medical field and what can it do for patients in times to come?

Stem cells can give rise to almost all of the 200 human cell types – liver, brain, skin, bone, nerve, intestine and so on. Stem cell treatment has the possibility to cure previously incurable fatal ailments like heart diseases, degenerative disorders of the nervous system, e.g. cerebral palsy, Alzheimer’s and Parkinson’s disease, paralysis of the spine due to physical trauma, and several types of cancer e.g. leukemia, osteosarcoma.

Stem cell therapy can substitute for the use of mechanical devices like titanium joints or insulin shots. Researchers and physicians have been trying to coax stem cells to transform into living replacements for diseased tissues and organs – the holy grail of regenerative medicine. Brain stem cells can now be safely transplanted in humans and have shown promise or neuroregeneration, at least in animal models. Irving Weissman with his team from ISCBRM, Stanford has been successful in engrafting stem cells that generate cancer-free blood corpuscles in leukemia patients.

Human embryonic stem cells (hESCs) are considered the best source for producing the entire range of human cell types. In 2009 the U.S. FDA approved clinical trials using hESCs on humans with acute spinal cord injury. Researchers have manipulated hESCs to grow into heart muscle cells, which when injected into diseased mice and pigs have effectively replaced ailing tissue leading to recovery. British scientists have discovered treatment for age-related blindness using hESC therapy. However, this line of treatment still face a lot of opposition due to the need to destroy human embryos to isolate hESCs. Stem cell therapy controversies are the main causes of delay in designing definitive cures through this biomedical technology.

Adult bone marrow stem cells and umbilical cord stem cells are other sources being used in treatment. Walter Low and his team from University of Minnesota have healed rats that suffered from brain damage due to stroke, using umbilical cord blood stem cells from humans. Trial is on to determine if this therapy is applicable to humans as well.

With stem cell therapy there has been the risk of host immune rejection after transplantation into the patient’s body. Japanese scientist Shinya Yamanaka circumvented this problem by designing iPSCs – induced pluripotent stem cells. He converted healthy skin cells into stem cells through genetic engineering. But iPSCs are made using retroviruses. So there is a risk of tumor formation if an error occurs in the process. Undaunted, scientists are trying to use small molecules to push mature cells back into pluripotency. Scientists in Cincinnati have used iPSCs to make functional human intestinal tissue in their laboratory.

The major challenge in stem cell research is simulating in the laboratory the normal environment inside the human body. The future of stem cell treatment depends on the ability of researchers to manipulate stem cells so as not to be rejected as foreign.