Breakthrough in cancer research
Scientists in California have found a way to “turn offâ€™â€™ 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 this week.
Cancer research scientists in Glasgow, Scotland, working with colleagues in Seattle in the United States, last year worked out the details of how a gene called Myc cranks up the rate of growth of dividing cancer cells by sending one of the cellsâ€™ “factories” into overdrive.
In the study, the mice were given a mutated Myc gene that was constantly “on”. It produced a protein that served as a kind of conductor, sending a signal to cells to divide.
Cancer cells produce too much Myc protein, and are constantly dividing.
The researchers fed the mice an antibiotic called Doxycycline, which turned the gene off, and consequently 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. When the mice were put back on the antibiotic diet, all of them showed rapid improvement: the liver cancer was eliminated, and liver cells seemed to behave normally.
In effect, the scientists turned the Myc gene on and off like a tap, turning the cancer on and off at the same time. They also found that some of the apparently normal cells retained the ability to become cancerous, which could explain why cancers often recur after chemotherapy.
Cancer affects one person in three, and kills one in five. But above all, cancer is a DNA disease, and British researchers have launched a cancer genome project to collect all the genetic mutations involved in the making of a cancer. There are more than 100, but the Myc protein seems to play a role in many cases.
However, what works in mice may not work so well in humans. The next step is to hunt for a drug that would be safe for human patients, and yet have the same impact. — Â