- Email: [email protected]
Cancer under control
CNRI/SPL
This week–
SOUNDBITES began to grow larger (Nature, DOI: 10.1038/nature06309). Schreiber says that this could happen naturally if someone’s immune system breaks down, perhaps through ageing, prolonged stress, or if someone takes immunosuppressive drugs to stop their immune system attacking a transplanted organ. “The immune system can keep tumours corralled in a dormant state that doesn’t become clinically apparent or harmful,” says Schreiber. “Many of us may be walking round with tumours in this equilibrium state.” It might be possible to stop cancers developing in the first place if researchers can identify the factors keeping the disease in equilibrium with the immune system. “Maybe we can convert –When it all goes horribly wrong– cancer from a deadly disease to a chronic, controllable state,” Schreiber says. Judah Folkman of the Children’s Hospital in Boston suspects the crucial factors might be signalling molecules that enable tumours to grow blood vessels. “Expansion of tumour mass beyond 2 millimetres system’s vigilance, it could open up new ways to fight cancer, requires continuous recruitment of new blood vessels,” he says. or even stop the disease Additional clues have come developing in the first place. from research showing a new Robert Schreiber at mechanism by which immune Washington University School of cells lose track of potentially Medicine in St Louis, Missouri, dangerous cells and tissues, and his colleagues injected mice including cancers. Leonie Taams with a carcinogenic chemical and her colleagues at King’s called methylcholanthrene to College London showed that they stimulate the growth of tumours could switch off the rallying call called sarcomas. While most of made by macrophages, white the tumours remained tiny and blood cells that alert the immune harmless, the researchers found system to the presence of that they could upset the invaders and abnormal cells. equilibrium by knocking out They did this by exposing the important components of the macrophages to immune cells immune system with artificial called regulatory T cells, which antibodies. are known to “switch off” When they knocked out white macrophages once an infection blood cells called CD4 and CD8 is under control or a wound cells, or the signalling molecule repaired. But Taams found that gamma interferon, the tumours the regulatory T cells could make the macrophages give a false “all “The immune system can clear” in certain situations keep tumours corralled in a (Proceeding of the National dormant state that doesn’t Academy of Sciences, DOI: become apparent or harmful” 10.1073/pnas.0706832104). ●
Learning to live (quite healthily) with tumours ANDY COGHLAN
ISN’T the immune system wonderful? Among its many talents, it can keep cancer in check for years without you ever knowing anything about it. That’s the implication of new research showing that animals can survive for years with tumours that are tiny and harmless because the dormant growths remain in equilibrium with the immune system. A person will only develop fullblown cancer if the microtumour changes – perhaps through a mutation that alters its outward appearance – so that it falls off the immune system’s radar. Or the immune system may slacken its surveillance and lose track of the tumour because the person is physically or mentally stressed, or fighting off an infection. If researchers can discover which molecules keep the tumours in check, or find ways of increasing the immune 10 | NewScientist | 24 November 2007
‹ I decided a few weeks ago not to pursue nuclear transfer.› Ian Wilmut, creator of Dolly the sheep, turns his back on the therapeutic cloning technique he has used, explaining that rival methods pioneered in Japan are more practical and “easier to accept socially” (The Daily Telegraph, London, 16 November)
‹ This is genuinely exciting news. These people have a juggernaut-sized heroin problem and I really don’t know whether we could turn it around.› John Strang, head of the UK National Addiction Centre, on a new scheme to set up “shooting galleries” where heroin users can obtain and inject the drug under supervision (The Independent, London, 20 November)
‹ You’re looking at a lot of dead animals, and we need a better way of dealing with it.› The state government of Michigan recently made it easier for farmers to compost dead livestock, but Lynn Henning of environmental body the Sierra Group is worried about toxic run-off (Associated Press, 16 November)
‹ They say it’s un-Canadian and you must leave the hospital if you want to do it.› Tom Louie, head of infection control at the Foothills Hospital in Calgary, Alberta, describing doctors’ reluctance to do a procedure involving faecal transplants, which apparently cures 90 per cent of patients with the Clostridium difficile superbug (CBC TV news, 14 November)
‹ As police we’re not experts in dealing with monkeys. We can deal with mad bulls but monkeys are more difficult.› Delhi’s deputy police commissioner Jaspal Singh laments a fresh wave of monkey attacks on the city’s population this month (AFP, 13 November)
www.newscientist.com
This week–
SOUNDBITES began to grow larger (Nature, DOI: 10.1038/nature06309). Schreiber says that this could happen naturally if someone’s immune system breaks down, perhaps through ageing, prolonged stress, or if someone takes immunosuppressive drugs to stop their immune system attacking a transplanted organ. “The immune system can keep tumours corralled in a dormant state that doesn’t become clinically apparent or harmful,” says Schreiber. “Many of us may be walking round with tumours in this equilibrium state.” It might be possible to stop cancers developing in the first place if researchers can identify the factors keeping the disease in equilibrium with the immune system. “Maybe we can convert –When it all goes horribly wrong– cancer from a deadly disease to a chronic, controllable state,” Schreiber says. Judah Folkman of the Children’s Hospital in Boston suspects the crucial factors might be signalling molecules that enable tumours to grow blood vessels. “Expansion of tumour mass beyond 2 millimetres system’s vigilance, it could open up new ways to fight cancer, requires continuous recruitment of new blood vessels,” he says. or even stop the disease Additional clues have come developing in the first place. from research showing a new Robert Schreiber at mechanism by which immune Washington University School of cells lose track of potentially Medicine in St Louis, Missouri, dangerous cells and tissues, and his colleagues injected mice including cancers. Leonie Taams with a carcinogenic chemical and her colleagues at King’s called methylcholanthrene to College London showed that they stimulate the growth of tumours could switch off the rallying call called sarcomas. While most of made by macrophages, white the tumours remained tiny and blood cells that alert the immune harmless, the researchers found system to the presence of that they could upset the invaders and abnormal cells. equilibrium by knocking out They did this by exposing the important components of the macrophages to immune cells immune system with artificial called regulatory T cells, which antibodies. are known to “switch off” When they knocked out white macrophages once an infection blood cells called CD4 and CD8 is under control or a wound cells, or the signalling molecule repaired. But Taams found that gamma interferon, the tumours the regulatory T cells could make the macrophages give a false “all “The immune system can clear” in certain situations keep tumours corralled in a (Proceeding of the National dormant state that doesn’t Academy of Sciences, DOI: become apparent or harmful” 10.1073/pnas.0706832104). ●
Learning to live (quite healthily) with tumours ANDY COGHLAN
ISN’T the immune system wonderful? Among its many talents, it can keep cancer in check for years without you ever knowing anything about it. That’s the implication of new research showing that animals can survive for years with tumours that are tiny and harmless because the dormant growths remain in equilibrium with the immune system. A person will only develop fullblown cancer if the microtumour changes – perhaps through a mutation that alters its outward appearance – so that it falls off the immune system’s radar. Or the immune system may slacken its surveillance and lose track of the tumour because the person is physically or mentally stressed, or fighting off an infection. If researchers can discover which molecules keep the tumours in check, or find ways of increasing the immune 10 | NewScientist | 24 November 2007
‹ I decided a few weeks ago not to pursue nuclear transfer.› Ian Wilmut, creator of Dolly the sheep, turns his back on the therapeutic cloning technique he has used, explaining that rival methods pioneered in Japan are more practical and “easier to accept socially” (The Daily Telegraph, London, 16 November)
‹ This is genuinely exciting news. These people have a juggernaut-sized heroin problem and I really don’t know whether we could turn it around.› John Strang, head of the UK National Addiction Centre, on a new scheme to set up “shooting galleries” where heroin users can obtain and inject the drug under supervision (The Independent, London, 20 November)
‹ You’re looking at a lot of dead animals, and we need a better way of dealing with it.› The state government of Michigan recently made it easier for farmers to compost dead livestock, but Lynn Henning of environmental body the Sierra Group is worried about toxic run-off (Associated Press, 16 November)
‹ They say it’s un-Canadian and you must leave the hospital if you want to do it.› Tom Louie, head of infection control at the Foothills Hospital in Calgary, Alberta, describing doctors’ reluctance to do a procedure involving faecal transplants, which apparently cures 90 per cent of patients with the Clostridium difficile superbug (CBC TV news, 14 November)
‹ As police we’re not experts in dealing with monkeys. We can deal with mad bulls but monkeys are more difficult.› Delhi’s deputy police commissioner Jaspal Singh laments a fresh wave of monkey attacks on the city’s population this month (AFP, 13 November)
www.newscientist.com