Testicles may be a source of stem cells

A team of researchers from Britain and Germany have found that a man's testicles may be a source of stem cells.

The researchers suggest that the sperm cells can possibly be coaxed into stem cells with similar properties to those found in the embryo, which offers the promise of a supply of "repair tissue" for other parts of the body.

Experts say any ability to transform cells taken from an adult back into stem cells, and then onwards into a wide variety of tissue types, offers the chance of "personalised treatment" for patients.

The resulting brain, bone, or heart cells could be injected without fear of rejection by the body's immune system and would also resolve the ethical controversies surrounding the use of stem cells taken from embryos.

The research project involved scientists from King's College London and the Institute of Anatomy, Tübingen, Germany - they used 22 different samples taken either from biopsies or from medical castrations, from which they extracted a type of cell called the "sperm precursor cell" - an adult stem cells with a fixed role - to become a sperm cell.

These were then chemically manipulated in the laboratory into a state more similar to cells found in the embryo, which can go on to produce all the cell types in the body, but as yet it is unclear whether the cells could one day be safely used in humans.

Professor Robin Lovell-Badge, a stem cell specialist from the Medical Research council National Institute for Medical Research, says the DNA in the stem cells in the testes lacks some important modifications that regulate the activity in certain genes, and this may affect the ability of the reprogrammed cells to make specific mature tissue types.

Professor Lovell-Badge says as the same cells are also the likely origin of testicular tumours, whether the reprogrammed cells will be entirely normal is unclear at this stage.

As to how these testis-derived pluripotent cells can be used is presently unknown and as the donors would be all male, women could not hope to benefit from similar procedures.

Professor Chris Mason, from University College London says whilst it is much too early to predict the true impact of this particular research, it is likely to add to the growing ground-swell of first-class research that will eventually lead to real benefits for patients.

Expert say it is too early to draw firm conclusions.

The research is published in the advance online publication of Nature.