Testicles to yield cures?

A man's testicles could one day provide a plentiful and accessible supply of adult stem cells to help him fight off disease or regenerate damaged organs, according to a study published Wednesday.

Researchers at Weill Cornell Medical College in New York have already isolated the multi-purpose cells in mice, and successfully coaxed them to grow into cardiac cells, brain cells and working blood vessel tissue.

Sidestepping debate
If the same technique can be extended to men, the study points out, it would sidestep the morally charged debate over using embryonic stems cells for the same purpose.

In experiments, a team led by Shahin Rafii of the Howard Hughes Medical Institute was able to cultivate "multi-potent adult spermatogonial-derived stem cells" (MASCs) without recourse to genetic manipulation.

"What is really novel about our work is that ... these mouse stem cells do not require any addition or tweaking of genes to get them to form multi-potent cells that then go on to produce all these cell types," said Rafii in a statement.

The reprogramming of adult cells in connective tissue to produce multi-potent stem cells, another technique used, carries an enhanced risk of malignancy, the researchers said.

Spermatogonial progenitor stem cells (SPCs) in the testes are specialised in the generation of the precursor of sperm.

Remarkably efficient
"They are remarkably efficient, keeping men fertile well into advanced age," said the study's lead author, Marco Seandel, who found a method for growing large quantities of SPCs in the laboratory.

Once this step had been mastered, another team set about concocting the perfect biochemical soup for tricking the SPCs to replace their normal function of creating germ cells with their newly assigned task of making "multi-potent" stem cells.

Stem cells, also found in the embryo and in bone marrow, can grow into almost any kind of cell or tissue in the body.

Already used to treat leukaemia, they hold enormous promise for the regeneration of failing organs and the treatment of Alzheimer's, Parkinson's, diabetes, arthritis and a host of other illnesses.

One advantage of generating stem cells from the patient is the elimination of any risk of tissue transplant rejection.

Doing the same in men
Extending these techniques to humans - men, in this case - is the next challenge, said Pier Paolo Pandolfi, a professor at Harvard who collaborated in the study published in the British journal Nature.

The researchers are hoping that the same method of genetic marking that allowed them to isolate the hard-to-spot SPCs in mice will also work for humans.

The study speculated that the approach might also work in the female ovary, which also contains a large population of germ cells, but said that experiments to test the theory had yet to be carried out. – (Sapa-AFP)

Read more:
Stem cells from testicles
Genetics Centre

September 2007