D express

Baby hopes for women struck down by cancer


YOUNG female cancer victims who risk losing their eggs or ovaries because of their treatment may still be able to have babies in years to come, scientist hope.
Researchers have managed to thaw frozen human ovary tissue and then revive it by grafting it on to mice. When they implanted it into genetically engineered mice, immature egg cells began to develop in the normal way.
One of the researchers at Melbourne’s Royal Women’s Hospital, Debra Gook, said the achievement often described as the holy grail of fertility research, had “real potential for clinical application”.
the research was hailed by leading fertility expert Professor Lynn Fraser, of King’s College London, chairwoman of the European Society for Human Reproduction and Embryology.
“These are very promising developments,” she said. “They hold out the possibility that we might use mice to preserve women’s fertility.”
Reimplantation with previously stored tissue would also allow such women to avoid an early menopausa.
Another team at the Mount Sinai Hospital in Toronto is also using mice to solve fertility problems. They are trying to incubate the eggs rather than whole tissue of women who risk damaging their ovaries because of medical treatment.
Because the Canadians are using eggs rather than ovarian tissue, this will be less use to young girls who have not yet made mature eggs.
Nonetheless Ariel Revel, who is leading the team which is developing the technology, says it “offers new hope” to young women who become infertile after vital medical intervention, such as cancer treatment.
[Our research holds out the chance for us to save fertility’]
These developments are sure to be controversial. There was an outcry in 1999 when Italian embryologist Severino Antinori claimed to have produced four babies using sperm grown in rats’ testes.
Professor Fraser warned that safety tests would need to be carried out, because if a patient had ovarian tissue removed and stored prior to radiotherapy, doctors would need to be sure that the removed tissue did not contain cancer cells. “There’s no point to using tissue at a later date if that is cancerous,” she said.
Many hospitals already freeze mature eggs from female patients. But freezing is difficult and can damage the eggs. While attempts to transplant ovarian tissue back into patients have so far failed. In cancer patients, malignant cells might also be reintroduced in the transplant process.
But another team of Italian scientist thinks it has got to grips with difficulties associated with the freezing process.
Fertility experts at the University of Bologna ha found that by increasing the sugar concentration in the freezing solution they could triple egg survival rates. Adding sugar minimizes the formation of ice crystals which can pierce the human egg membrane, killing it in the process.
“It will offer hope to women who lose their fertility through medical treatment or who may be at risk of premature menopause,” said Dr Raffaella Fabbri, whose research is published in the journal Human Reproduction.
“The survival rate of the eggs with the new technique is about 80 to 83 per cent,” said Dr Fabbri. “Before, it was between 35 and 60 per cent.”


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