The researchers, led by Dr Hajime Ogushi of Japan’s National Institute of Advanced Industrial Science and Technology (AIST), created stem cells ‘of the type found in human embryos’ from wisdom teeth removed from a 10 year old girl during a routine dental operation.
After isolating the cells they were converted into ‘embryonic-like’ stem cells which could be differentiated into a range of adult cells and may help the development of new cell lines upon which to screen new drugs as well as becoming a treatment in their own right.
"This is significant in two ways, one is that we can avoid the ethical issues of stem cells because wisdom teeth are destined to be thrown away anyway,” Dr Ogushi told the AFP news agency.
"Also, we used teeth that had been extracted three years ago and had been preserved in a freezer. That means that it's easy for us to stock this source of stem cells."
In 1998, Professor James Thomson of the University of Wisconsin at Madison, US, became the first scientist to extract stem cells from a fertilised human embryo that could differnetiate into over 200 types of different cell.
This revelation sparked a bitter debate about whether research of this type should be allowed, with religious conservatives arguing that such research destroys human life at its earliest stage of development.
Since then, scientists have used techniques such as somatic cell nuclear transfer (SCNT) to replace the nucleus of an unfertilised embryo with a nucleus from another cell to enable animals such as Dolly the sheep to be cloned.
In November last year, a team from the University of Kyoto, Japan, led by Dr Shinya Yamanaka generated human stem cells ‘that exhibit the essential characteristics of embryonic stem cells," by introducing four genes, OCT3/4, SOX2 KLF4 and the oncogene c-MYC, into a sample of adult human skin.
Simultaneously, Prof. Thomson’s group published results describing how the introduction of OCT3/4, SOX2, NANOG and LIN28 turned foetal fibroblasts or postnatal foreskin fibroblasts into embryonic-like stem cells,
Dr Ogushi’s team introduced three of the genes used by Dr Yamanaka’s team into the tissue from the wisdom teeth to create the embryonic-like stem cells.
However, Dr Ogushi estimates that it will take at least five years to put the method into clinical use as a trial treatment for congenital bone disease.
"Because extractions of wisdom teeth are commonly operated in dental clinics, we can expect a lot of donors of stem cells," said Dr Ogushi.
"That will enable us to create stem cells of various genetic codes, eliminating the risk that a body of a patient would reject transplanted tissues or organs."