05 November 2012
ByAppeared in BioNews 680
Banked sperm-producing stem cells have been used to restore sperm production in monkeys made infertile by chemotherapy treatment. This is the first time such restoration has been achieved in large animals that have undergone chemotherapy, building on previous work carried out following radiotherapy treatment.
The stem cells which give rise to sperm - spermatogonial cells - can often be lost during cancer treatment, leading to infertility. The researchers removed these cells from monkeys and cryopreserved them before chemotherapy treatment. A few months after the treatment, the stored stem cells were implanted back into the animals. Nine out of 12 adult monkeys and three out of five pre-pubescent monkeys were later able to produce sperm.
The scientists hope their study represent a step towards a viable fertility preservation technique for younger male cancer patients. While not producing mature sperm, pre-pubescent boys do have spermatogonial stem cells, which will start to produce mature sperm cells after puberty.
Study leader Dr Kyle Orwig, from the University of Pittsburgh in the USA, who led the study, said: 'Men can bank sperm before they have cancer treatment if they hope to have biological children later in their lives, but that is not an option for young boys who haven't gone through puberty [and] can't provide a sperm sample'.
The work has been welcomed by other researchers. Dr Pierre Fouchet, a researcher at the CEA Institute of Cellular and Molecular Radiobiology in France, told the BBC that the findings 'constitute a milestone in the field of reproduction'.
Nonetheless, Dr Orwig admits that many challenges need to be overcome before the technique can be used in humans. 'Should we re-introduce the spermatogonial cells as soon as treatment is over, or wait until the patient is considered cured of his disease, or when he is ready to start a family?' he said. 'How do we eliminate the risk of cancer recurrence if we give back untreated cells that might include cancer cells?'
The study is published in the journal Cell Stem Cell.