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The race to find genetic therapies to cure diabetes heated up yesterday as researchers announced they had rid mice of the disease by tricking their livers into producing insulin.
Experiments by US scientists employed a gene called neuroD to make mice's livers behave like healthy human pancreases and produce the hormone insulin that is vital to converting glucose in blood into energy.
The team used an adenovirus, one of a family of viruses responsible for colds, coughs, and other infections, but which had its toxic properties removed, to carry the gene into the liver. But the gene alone only partially corrected the disease.
The new beta cells producing insulin and other hormones were aided by adding a special growth factor called Btc. This combination cured diabetes in mice for at least four months, according to the scientists at Baylor College of Medicine, Houston, Texas.
Lawrence Chan, who headed the team, said the treatment was still "further from people than I would like". The main stumbling block was the virus that acted as carrier for the gene. He expected safer ones to be available within 10 years: "We want to use the safest vector possible."
The research, reported last night in the online edition of Nature Medicine, comes just four months after British scientists announced a gene breakthrough. Researchers at the University of Bath, funded by the Wellcome Trust and the government-financed Medical Research Council, suggested that within a decade their work could lead to similar tricking of human livers into behaving like pancreases.
They used a different gene, a superactive version of one called Pdx, to make human liver cancer cells grown in bottles behave like pancreatic cells. Modification of cells in tadpoles from the African clawed frog were also made to create insulin-producing cells and other cells with enzymes to digest food. The British team have held out the hope of diabetic patients eventually being cured by a one-off injection that allows their bodies to effectively convert part of their liver into a new pancreas.
About 1.4 million Britons have diabetes, nearly a quarter of type one, the form which requires regular, often daily, insulin injections, the remainder type 2 which can normally be controlled by diet and exercise.
The condition is a complicating factor in obesity and heart disease, in addition to its own threats of coma, blindness and poor quality of life.
The scale of the problem is growing rapidly, with an estimated 300 million people having diabetes worldwide in 20 years, putting strains on many countries' health budgets.
The hope is that gene therapy might offer an alternative to another promising but still rare treatment which is undergoing trials in Britain. This involves transplanting cells from other people's pancreases into patients. But patients, even if freed from insulin injections, would have to take anti-rejection drugs for the rest of their lives and there is a shortage of potential donors.
Content provided by ArmMed Media
Revision date: 12 December 2007
Last revised by Amalia K. Gagarina, M.S., R.D.
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