'Cell taming' clue to tackling leukaemia

By suppressing a protein in the blood, scientists were able to switch leukaemic stem cells back to a pre-cancerous stage of development.

More aggressive leukaemic stem cells that had become resistant to treatment were "re-sensitised" to anti-cancer drugs.

The study, reported in the journal Cancer Cell, involved a dangerous strain of leukaemia driven by defects in the MLL (mixed lineage leukaemia) gene.

MLL cancer accounts for around 70 per cent of infant leukaemias and 10 per cent of those affecting adults.

Only 50 per cent of children diagnosed with MLL leukaemia survive longer than two years after receiving standard therapy.

Professor Eric So, who led the King's College London team, said: "The findings provide compelling evidence that this protein could be exploited to develop an effective therapeutic target for this form of the disease."

Stem cells are immature cells that can develop in a number of different directions.

Some are precursors of cancer cells. Leukaemic stem cells are part-way along the path that leads to cancerous white blood cells, although not all of them reach this stage.

The King's College researchers focused on a blood protein called beta-catenin.

Suppressing this protein delayed the onset of cancer, slowed down cancer growth, and reversed leukaemic stem cells to a pre-cancerous stage. When beta-catenin was inactivated in mice with pre-leukaemic cells, the animals did not develop cancer despite carrying all the necessary MLL mutations.