London: Scientists claim to have turned skin cells directly into brain cells, thus completely bypassing the need for stem cells, probably for the first time in a study on
A team at the Stanford University School of Medicine says it`s "thrilled" at the potential medical uses though more tests are needed before the technique could be used on humans, `Proceedings of the National Academy of Sciences` reported.
Stem cells, which can become any other specialist type of cell from brain to bone, are thought to have huge promise in a range of treatments. Many trials are taking place, but there are ethical issues around embryonic stem cells.
An alternative method has been to take skin cells and reprogramme them into "induced" stem cells. These could be made from a patient`s own cells and then turned into the cell
type required, however, the process results in cancer-causing genes being activated.
So, the scientists are looking at another option -- converting a person`s own skin cells into specialist cells, without creating "induced" stem cells, the `BBC` reported.
In fact, in their study, the scientists created "neural precursor" cells, which can develop into three types of brain cell -- neurons, astrocytes and oligodendrocytes.
These precursor cells have the advantage that, once created, they can be grown in a laboratory into very large numbers. This could be critical if the cells were to be used
in any therapy, say the scientists. Brain cells and skin cells contain the same genetic information, however, the genetic code is interpreted differently in each. This is controlled by "transcription factors".
So, the scientists used a virus to infect skin cells with three transcription factors known to be at high levels in neural precursor cells. After three weeks about one in 10 of
the cells became neural precursor cells.
"We are thrilled about the prospects for potential medical use of these cells. We`ve shown the cells can integrate into a mouse brain and produce a missing protein important for the conduction of electrical signal by neurons.
"More work needs to be done to generate similar cells from human skin cells and assess their safety and efficacy," team leader Prof Marius Wernig was quoted as saying.