New technique to prevent tumours developing in connection with stem cell transplantations

Researchers at Lund University have come up with a new technique to prevent tumours developing in connection with stem cell transplantations. The results have been published today in the respected scientific journal PNAS.

"When you develop, for example, nerve cells for transplantation, you always get a small contamination of immature stem cells", explains Johan Jakobsson, head of research group at the Department of Experimental Medical Science.

These immature stem cells can lead to tumours - an unacceptable side-effect.

"We have developed a technique that enables us to eliminate immature stem cells and thus create safer stem cell transplantations."

The researchers have transplanted the stem cells into mice with Parkinson's disease. The results are very promising: there are far fewer tumours and the cells that survive are the correct type of nerve cells.

The technique uses a specially designed virus.

"We use the virus to genetically modify the cells, which means that we can see which ones we want and which ones we don't want. You could say that we hijack one of the cell's gene regulation systems, microRNA. The cell itself tells us when it is mature; it is black when it is immature and turns green when it has completed its development."

It is relatively simple to isolate, cultivate, preserve and genetically modify stem cells. If transplanted into humans they could replace damaged tissue in the nervous system and support other cells that work to heal a brain injury.

"For us this is a major step. Previously tumours have always developed with this type of transplantation. Now we have shown that this can be avoided", says Johan Jakobsson.

At Lund University collaborations are underway on stem cell therapy, for example, for Parkinson's disease, diabetes, stroke, leukaemia and breast cancer. The research community has set the goal of making stem-cell based treatment effective and safe for at least one of the diseases within the next 10 years.

"Our technique could in theory be used for all these diseases", says Johan Jakobsson. The next step is to conduct experiments on human cell lines.