18 December 2010 | NewScientist | 17

HUNDREDS of infants who die each year from an aggressive form of leukaemia could one day be saved, thanks to the discovery of the disease’s weak spot.

Mixed-lineage leukaemia (MLL) accounts for 70 per cent of leukaemia in infants under two, half of whom will die within two years. Eric So of King’s College London and colleagues have discovered a protein that both

drives the development of MLL and makes it resistant to treatment.

The guilty protein is beta-catenin, a transcription factor which activates other genes. In experiments on normal and MLL cells from mice and humans, the researchers demonstrated that beta-catenin is activated in cancer stem cells that prompt leukaemic blood cells to multiply. When the team used fragments of

Alien tree spotters look for shadows

IT SOUNDS like a zen koan. If a tree on an alien world falls, would we notice? Christopher Doughty of the University of Oxford and Adam Wolf of Princeton University think we just might.

They say the shadows cast by trees would change the amount of light a planet reflects as it orbits its star. When the planet is behind its star as seen from Earth – as the moon is during its full phase – the trees would cast little shadow, while at other points in its orbit the shadows would grow longer. Future telescopes should be able to search for these changes (Astrobiology, DOI: 10.1089/ast.2010.0495).

Nancy Kiang of the NASA Goddard Institute for Space Studies in New York City says steep mountains could mimic the effect. But Wolf notes that less than 1 per cent of Earth’s surface has a slope of 45 degrees or more.

Imagine stuffing yourself to curb hunger pangs

IF YOU want to fight the flab during the party season, you will be trying to push thoughts of tasty treats out of your mind. Imagining eating a particular food may, however, help us put away less of the real thing.

Joachim Vosgerau at Carnegie Mellon University in Pittsburgh, Pennsylvania, and colleagues studied the effect of mental processes on habituation – the weakening of our response to a stimulus when it is repeated. Knowing that our responses to sensory perception and mental representation overlap – for example, the thought of a spider crawling up your leg

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in Brief

At last, infant leukaemia has weak spot interfering RNA to sabotage the production of beta-catenin in these stem cells, the blood cells returned to an early leukaemic state. The cells stopped multiplying and became vulnerable to treatment with drugs (Cancer Cell, DOI: 10.1016/ j.ccr.2010.10.032).

Next the team hope to test drugs that block the function of beta-catenin, which is also implicated in the development of skin and colorectal cancers.

can induce the same sweat response as the real thing – Vosgerau’s team reasoned that thinking about eating food could lead people to habituate to the action itself.

Volunteers were asked to imagine inserting 33 coins into a laundry machine – an action that the researchers thought was similar to eating M&M’s. A second group imagined inserting 30 coins and eating three M&M’s; a third imagined inserting three coins and eating 30 M&M’s.

All participants were then allowed to eat freely from a bowl of real M&M’s. Those who had imagined eating 30 M&M’s consumed significantly fewer of the real thing than people in the other groups, suggesting that eating in imagination can cause habituation to real food. The finding could mean new approaches to weight loss and drug treatment (Science, DOI: 10.1126/science.1195701).

ONLY one animal – the fearless fire ant – eats the eggs of channelled apple snails (Pomacea canaliculata), and now we know why. The eggs contain an enzyme inhibitor that makes them, quite literally, indigestible. The snails are the first animal found to use this tactic to repel predators.

The eggs are laced with ovorubin, a bright red protein that Horacio Heras and colleagues at the National University of La Plata in Argentina have found is key to their impregnability.

Ovorubin turns off digestive enzymes that break down proteins. Heras fed rats an ovorubin-enriched diet and found that they grew more slowly than normal (PLoS One, DOI: 10.1371/journal.pone.0015059).

Weaponised eggs turn stomachs