Targeting and inactivating a key gene could be a subtle and effective treatment for certain types of ovarian cancer, Scottish researchers suggest in a study published in Clinical Cancer Research.
Cancer Research UK scientists at The University of Edinburgh found that blocking a gene called Raf-1 can halt the growth of some ovarian cancer cells while leaving others largely unaffected. Their findings could lead to selective cancer therapies tailored for individual patients.
Researchers also gained important clues about why targeting the gene was effective in some types of cancer but not in others, paving the way for a test to predict which patients would benefit from the treatment.
The Raf-1 gene is switched on in over 90 per cent of ovarian tumours and scientists believe it plays an important role in the disease's development. Like other genes it is controlled by the molecular equivalent of a dimmer switch and the cancers where it is turned up highest tend to have the worst survival. Scientists believe Raf-1 helps to trigger the process of cell division, allowing cancer cells to ignore the normal controls on their growth and to divide much more quickly than usual.
Researchers from the Cancer Research UK Edinburgh Oncology Unit, Western General Hospital, cultured cells from 15 ovarian tumours in the laboratory. They used short stretches of DNA called antisense oligonucleotides to interfere with the activity of Raf-1 and measured the effects on cell growth.
In some cell types, blocking the gene reduced the rate of cell growth by over 90 per cent and caused widespread cell death. But in others treatment had only a moderate effect, with growth falling by just 10-40 per cent.
Lead researcher Dr Simon Langdon, of the Cancer Research UK Edinburgh Oncology Unit, says: "Ovarian cancers often become resistant to conventional chemotherapy, so there's a real need to develop new, more subtle therapies that attack cancer cells in new ways. Our study highlights the potential of the Raf-1 gene as an exciting target for future cancer drugs. It looks as though therapies aimed at Raf-1 might be highly specific for a particular group of ovarian cancers and would hopefully leave healthy tissue relatively unaffected."
Researchers believe it should be possible to test ovarian tumours to see if they are likely to respond to treatments aimed at Raf-1.