However, these are immature cells. If they succeed in ripening them, the process may help in fertility treatments for men whose sperm have been damaged, for example by radiation against cancer tumors
Scientists said they succeeded in developing sperm cells, albeit not fully matured, from human bone marrow tissues. If it is possible to successfully "grow" the sperm cells and reach a state where the cell is developed, which the researchers believe will take another five years, this may be useful in fertility treatments. However, experts warned that the findings from a study conducted in Germany should be taken with caution and, at least at this stage, it is proposed in the UK to prohibit the use of this process in fertility treatments.
Researchers from the Universities of Göttingen and Münster and the Medical School in Hannover, succeeded in isolating mature stem cells - cells that have the ability to become many types of tissue in the body - from bone marrow sections taken from male volunteers.
Normally, stem cells from the bone marrow will develop into different types of muscle cells. However, the researchers were able to get a small number of them to develop into what appear to be spermatagonial cells, cells found in the testicles that in due course develop into mature sperm cells capable of fertilizing an egg.
This is the first time that pre-sperm cells are created artificially in this way. The lead researcher in the project, Prof. Karim Nayernia, who has since moved to a stem cell institute in the northeast of England located at the Life Sciences Center in Newcastle, said that he hopes that his research will one day enable the treatment of young men whose fertility has been damaged by chemotherapy treatments.
"Our next goal is to see if we can transform these cells into mature sperm cells in the laboratory and we anticipate that this process will take 3-5 years of experimentation. However, he commented that the law could be an obstacle.
Professor Harry Moore from the Center for Stem Cell Biology at the University of Sheffield tells the BBC: "These findings are interesting but we still need to be careful in their interpretation.
The change of the stem cells was observed by the researchers and they turned from pre-muscular cells into reproductive cells, in a process known as trans-differentiation. However, Professor Moore says that almost all similar observations of this process in adult stem cells were not confirmed when repeated experiments were carried out, since the result could be misleading. According to him, "This is a rapidly advancing field, but it will be years before we can develop any fertility treatment that makes use of these types of techniques."
A fertility policy document recently published by the British government proposes to ban the use of artificially created sperm or egg to help bring children into the world.
