An experimental approach has shown promise in rats for preventing heart arteries from reclosing after they have been opened with angioplasty, researchers reported Wednesday.
The research represents the first time that scientists have used a new genetic approach called "antisense" to treat an animal, offering encouragement that the technique may be useful for treating heart disease and other illnesses."This basic science development could give physicians a powerful new tool to treat (heart) disease," said Dr. Claude Lenfant, director of the National Heart, Lung and Blood Institute, which financed the research.
"This important research also could open a new door in medicine, leading to a novel type of therapy that is non-toxic and able to affect only a specific site rather than an organ system or the whole body," he said.
About 250,000 Americans undergo angioplasty each year in the United States. The procedure involves expanding a tiny balloon inside arteries supplying blood to the heart that have become narrowed by fatty buildups, increasing the risk for heart attacks. Inflating the balloon widens the arteries, restoring blood flow.
But in about one-third of cases, the arteries eventually narrow again, requiring doctors to repeat the angioplasty or replace the arteries through bypass surgery.
Antisense, which previously had only been used on plants, animal cells in the laboratory and primitive single-cell organisms, works by blocking the function of specific genes.
Genes work by sending instructions for the production of proteins, which carry out functions throughout the body. Antisense molecules are laboratory-made molecules that correspond to a gene's signal, binding to the signal and thereby blocking its action, preventing the protein from being produced.
In a paper published in the British journal Nature, Robert Rosenberg and his colleagues at the Massachusetts Institute of Technology developed an antisense molecule designed to block the production of a protein needed for cells inside arteries to divide, which contributes to arteries narrowing.
The researchers then performed angioplasty on laboratory rats and treated some of the rat arteries with the antisense molecule. Those treated did not narrow within two weeks, which is when reclosure usually occurs, the researchers said.
Based on the findings, the researchers suggested the approach could be used on humans by applying the material to arteries at the time of the angioplasty. Testing could begin within two years, they said.