Enzyme found to promote cancer

A sugar-regulating enzyme that was thought to protect against cancer actually promotes a deadly form of leukaemia, scientists have found.

Researchers believe glycogen synthase kinase 3 (GSK3) could provide a new therapy targeting paving the way to new treatments.

The protein is one of a number of biological catalysts that help control sugar levels in the muscles and liver. It was previously found to halt uncontrolled cell growth, preventing several kinds of cancer.

But new data from the US show that GSK3 fuels a deadly white blood cell cancer that accounts for between 5% and 10% of child and adult leukaemias.

MLL or "mixed lineage" leukaemia is a particularly dangerous form of the disease that can either start in the lymph nodes or bone marrow.

Laboratory tests and experiments with mice showed that inhibiting GSK3 combated MLL leukaemias. More work is needed to find out how GSK3 revs up the disease.

Study leader Professor Michael Cleary, from Stanford Cancer Centre in California, said: "This finding was quite unexpected. GSK3 has never been implicated in promoting cancer."

Previous research had shown that GSK3 slows down malignancies such as colon cancer.

The scientists, who report their discovery in the journal Nature, are now hunting for potent GSK3-inhibitors that can safely be given to humans. GSK3 is said to be an especially promising target because it normally puts a brake on the growth of bone marrow stem cells.

Drugs that inhibit the enzyme may have a double whammy effect, killing cancerous blood cells and promoting the growth of healthy stem cells such as those used in marrow transplants.
http://ukpress.google.com/article/ALeqM5iXGBy9nnmNs61RCRWHVfC80dKbbg