Scientists 'switch off' cancer gene

London: Scientists in California have found a way to ``turn off'' a gene that makes cancerous cells lethal. They eliminated aggressive, incurable liver tumours in laboratory mice in four weeks, they report in an advance paper in Nature on Monday. The study, based on a gene called Myc, could lead to new ways of treating cancer. Cancer Research U.K. scientists in Glasgow, working with colleagues in Seattle, worked out the details of how Myc cranks up the rate of growth of dividing cancer cells by sending one of the cell's factories into overdrive. In cancer, cells divide uncontrollably. The California team based their studies on mice with genetically modified liver cells. The mice under study had a mutated Myc gene that was constantly on. It produced a Myc protein that served as a kind of conductor, sending a signal to cells to divide. Cancer cells produce too much Myc protein all the time, and are constantly dividing. Dr. Felsher and his colleagues fed the mice an antibiotic called doxycycline, which turned the gene off, and stopped the protein flow. As long as the mice had the antibiotic diet, they remained healthy. Once the antibiotic was withheld, they developed aggressive liver cancer in 12 weeks. In effect, the scientists turned the Myc gene on and off like a tap, and turned cancer on and off at the same time.

Guardian Newspapers Limited 2004

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