Mice breakthrough raises hope for cystic fibrosis cure
The Times
17 September 1992
Nick Nuttall
The search for a cure for cystic fibrosis has been given a boost by British scientists who have developed genetically engineered mice suffering from the disease.
The mice, produced by a technique known as gene targeting, open the way for testing new drugs and "gene therapies" in which copies of healthy human genes are sprayed or injected into afflicted parts of the body to produce missing proteins. The development gives hope to the victims of one of the western world's most distressing diseases. There are 6,000 sufferers in the United Kingdom alone.
The modification and successful breeding of the animals is being hailed as a breakthrough for the British research team, which is based at the Medical Research Council's human genetics unit in Edinburgh.
At least three groups of scientists have been racing to devise an animal model for cystic fibrosis - a disease linked with a fault in the mechanism that transports salt across cell membranes - so that treatments can be improved and new ones tested. The main treatment at present involves antibiotics.
The British effort, details of which are published in the journal "Nature", appeared to have been pipped at the post when in August scientists at the University of North Carolina announced in the journal "Science" that they had genetically modified a mouse.
However, it has emerged that the animals are far from satisfactory. Some bred with the modified gene have none of the diseases's classic symptoms including the build-up of thick clogging mucus in the lungs, damaged digestive systems and abnormal male gonads. Others have the symptoms but they are too severe.
In addition many of the American team's animals are dying at birth with few living beyond weaning. The British mice, in contrast, are starting to show all the classic abnormalities linked with the disease, mirroring very closely those seen in humans, as well as surviving in large numbers.
The work has been led by David Porteous in collaboration with colleagues including Julia Dorin of the Cystic Fibrosis Trust in London.
The modified gene was made by inserting into it a piece of DNA that blocks the gene's ability to make a key protein. It is the absence of this protein which triggers cystic fibrosis.
Over recent months there has been growing concern over the patenting of genetically modified life forms, a move being pioneered by American researchers.
The development of the Edinburgh mouse should ensure that British cystic fibrosis research can proceed without depending on overseas animals. Dr Martin Scott, of the Cystic Fibrosis Trust, said that the superior characteristics of the mice should also lead to a strong demand for the animals from overseas researchers keen to test their own treatments.
American researchers have pinpointed a mutation on a gene which appears to cause cancer of the colon. The gene, which is called APC, normally protects against the development of tumours by helping to stop unwanted cell division.
The researchers, based at the John Hopkins Oncology Centre in Baltimore, Maryland, discovered the mutation after screening a large number of tumours in the early stage of development.
The researchers believe that the findings could help the development of drug therapies for the disease.
Meanwhile scientists at the Baylor College of Medicine, Houston, Texas, claim to have identified a mutation in another gene which appears to be responsible for a kidney disorder, inherited in new-born boys from their mothers, called congenital nephrogenic diabetes insipidus.
The scientists report in "Nature" that the disease interferes with the kidneys' ability to take up water prior to urine excretion.
