Cancer drugs may treat aging syndrome in children

Drugs being developed to treat cancer may also help children with a disease called Progeria (also known as Hutchinson-Gilford syndrome), which accelerates aging and often kills patients when they are in their teens, U.S. researchers reported on Tuesday.

The researchers found a group of drugs known as farnesyltransferase inhibitors (FTIs) could restore the normal shape of cells damaged by Hutchinson-Gilford progeria syndrome (HGPS).

The drugs are already being tested in children and appear to be safe, the researchers said in two separate reports published in the Proceedings of the National Academy of Sciences.

“We are doing experiments to see if it actually works in animals,” said Stephen Young of the University of California Los Angeles, who led the first study, in a telephone interview.

Causes, incidence, and risk factors

Progeria is a rare condition but has come into public awareness because its symptoms strongly resemble normal human aging as well as the appearance of several affected children in movies on national television.

Lamin A is the name of the gene recently identified as causing some types of progeria. Lamin A codes for a protein that surrounds the nucleus of cells. Further study of lamin A will hopefully answer why mutations in this gene cause such striking premature aging.

Progeria results in rapid aging of children, beginning with growth failure during the first year of life that results in disproportionately small bodies given the size of their heads. The children are thin with baldness, wizened narrow faces, and old-appearing skin.

Children with progeria develop early atherosclerosis. The average lifespan is the early teens. However, some patients can live up to 30 years. The cause of death is usually related to the heart or a stroke as a result of the progressive atherosclerosis.
More information Progeria

His team, which is also testing other types of drugs, said the findings could help lead to treatments for progeria and perhaps related disorders, including Osteoporosis and hardening of the arteries as well as rare conditions caused by similar processes.

One in 4 million children are born with progeria, which causes dramatically accelerated aging and early Heart disease. Children become wizened, losing their hair, developing wrinkles and thin bones. They usually die from hardened arteries before they are 15.

Progeria is caused by mutations in the gene for a protein called lamin A, important for normal function in cells. The abnormal protein results in a deformed cell nucleus, causing miscommunications with other cells.

Symptoms

     
  • Growth failure during the first year of life  
  • Narrow, wizened (shrunken or wrinkled) bird-like faces  
  • Baldness  
  • Loss of eyebrows and eyelashes  
  • Short stature  
  • Large head for size of face (macrocephaly)  
  • Soft spot (fontanelle) remains open  
  • Small jaw (micrognathia)  
  • Dry, scaly, thin skin  
  • Limited range of motion  
  • Teeth - delayed or absent formation

Young’s team found in July that FTIs corrected this deformity in mice bred to develop a disease similar to progeria.

In their study published this week, the researchers report that they confirmed their findings in cells taken from children with progeria. A second team at the National Human Genome Research Institute (NHGRI), the Howard Hughes Medical Institute and elsewhere, made similar findings.

“FTIs, originally developed for cancer, are capable of reversing the dramatic nuclear structure abnormalities that are the hallmark of cells from children with progeria,” said NHGRI director Dr. Francis Collins in a statement.

“This is a stunning surprise, rather like finding out that the key to your house also works in the ignition of your car.”

Collins said it might be possible that the drugs, or similar drugs, could affect normal aging.

“We are exploring the possibility that FTIs might also slow down the aging process in normal cell cultures, but we don’t have any data on that yet,” he said in an e-mail.

Two FTIs are in phase III clinical testing, the last stage before U.S. Food and Drug Administration approval. One is called lonafarnib and is made by Schering-Plough and another called tipifarnib is made by Johnson & Johnson.

But other approaches may work, too, said Young - including newer drugs called antisense and RNA interference, which directly affect the genetic defects as opposed to interfering with the faulty protein.

In addition, Young’s team found that an osteoporosis drug called alendronate may help treat progeria by interfering with the faulty protein. Unpublished experiments have shown it also improves the misshapen nucleus.

But they said it is too early to test such drugs in progeria patients. “What’s attractive about it is the drugs are incredibly safe,” Young said.

Provided by ArmMed Media
Revision date: July 9, 2011
Last revised: by Tatiana Kuznetsova, D.M.D.