2009.09.27 – Scientists find broken ‘switch’ link to leukemia


Scientists find broken ‘switch’ link to leukemia

heraldscotland staff

Published on 27 Sep 2009

A broken genetic “switch” has been discovered that can trigger leukaemia.

Scientists believe the discovery – lifting the lid on a previously unknown messaging mechanism in cells – could lead to new treatments.

Leukaemia is a cancer of the bone marrow and the immune system’s white blood cells, which do not develop properly and begin to divide uncontrollably.

Like the HIV Aids virus, the disease leaves the body less able to fight off infections. It also disrupts the manufacture of red blood cells, leading to anaemia.

Leukaemia affects more than 7,000 people in the UK each year and causes 4,350 deaths.

Scientists are still unclear about what causes the cancer. The disease has been linked to smoking, exposure to radiation, and infection by a virus that attacks white blood cells. People with Down’s syndrome also have a higher risk of developing leukaemia.

The new research implicates a gene called JAK2 that acts as a master switch, turning different genes on or off.

Previously JAK2 was only thought to function on the inner surface of cells. But investigators at the Wellcome Trust/Cancer Research UK Gurdon Institute at Cambridge University found that it also acts at the heart of the cell, in the nucleus.

There, an enzyme made by JAK2, controls the activity of other genes by altering proteins called histones that pack and protect DNA.

When JAK2 develops a fault its messages can become garbled, leading to chaos in the workings of the cell and triggering cancer.

Professor Tony Kouzarides, director of the Gurdon Institute, said: “This is a completely new route by which cancer can develop. In this exciting research we have revealed new unidentified parts of the cell’s messaging system which can become faulty and lead to leukaemia.”

The research is published today in the online edition of the journal Nature.

Professor Sir David Lane, Cancer Research UK’s chief scientist, said: “This is important research which will helps scientists find new and better ways to treat people with leukaemia.

“Leukaemia can be difficult to treat because cancer cells are spread widely through the body so surgery is not an option. This makes it crucial to develop effective drugs to manage and treat the disease.

“These findings reveal a new route by which leukaemias develop, and gives scientists new opportunities to develop drugs which block it.”

Dr David Grant, scientific director at the charity Leukaemia Research, said: “It is only a few years since mutations in the JAK2 gene were first linked to leukaemia.

“Since then patients have already benefited from better diagnosis and treatment because of early detection of the mutation.

“Now that this research has demonstrated how the mutated gene works, it will lead to even more rapid progress in designing new treatments for patients.”