Human eggs grow in mice muscle tissue

Human eggs grow in mice muscle tissue

URL: http://www.globeandmail.com/gam/Health/20000627/HE27MICE.html

Date accessed: 15 July 2000

Reuters

Tuesday, June 27, 2000

London -- Canadian scientists have transplanted human ovarian tissue

into the muscles of mice to grow human eggs in a technique they say

could one day be used to retain the fertility of cancer patients.

Researchers from the Samuel Luenfield Research Institute at Mount Sinai

Hospital in Toronto told the European Society of Human Reproduction

and Embryology (ESHRE) conference in Bologna, Italy that it was the

first time tissue from the human ovarian cortex has been grafted and

yielded eggs.

The ovarian cortex is the surface of the ovary which contains the follicles

that produce the eggs.

"The possibility of preserving the ovarian cortex prior to surgery, drug or

radiotherapy treatment offers new hope for young cancer patients," Dr.

Ariel Revel said in a statement released in London.

Dr. Revel and his colleague Dr. Hila Raanani have used fresh and frozen

ovarian tissue to successfully grow human eggs in mice. They now plan

to see if the eggs retrieved from the mice muscle mature in the laboratory

and if they are normal.

"If all goes well we could be ready to begin IVF [in vitro fertilization] in

the first patients in a year or so," he said.

Fertility centres are already freezing ovarian tissue and human eggs of

women undergoing cancer treatment or other medical procedures which

could damage their fertility. But freezing can damage the eggs, which are

very fragile.

Transplanting the tissue back into the patients is also difficult. For cancer

patients there is also the danger that the tissue may contain cancerous

cells.

The scientists used the ovarian cortex donated by a woman who was

having her ovaries removed and her ovarian tissue frozen. They used a

special species of mice which have no immune system so the animals

would not reject the graft.

The scientists transplanted the tissue into muscle on the backs of the

mice, which were given follicle stimulating hormone (FSH) to make the

eggs grow. Another hormone was used to imitate ovulation and the eggs

were retrieved 36 hours later.

"Maturing eggs in culture is difficult as it take weeks before primary

follicles develop the receptors to respond to FSH, so starting off the

maturing process in the living environment provided by mice muscles is a

major advance," Dr. Revel said.