Life-saving solutions to the problem of why some women with breast cancer become resistant to a “gold-standard” drug may result from a breakthrough by Cancer Research UK.
Tamoxifen is a highly effective drug that prevents tumours being fuelled by the female sex-hormone oestrogen. Scientists at the Cambridge Research Institute have now discovered why some patients develop resistance to it.
They have found a molecule named PAX2 that helps tamoxifen work by switching off a cancer-promoting gene. But tamoxifen-resistant tumours have more of another molecule, AIB-1, which keeps the cancer gene switched on.
If AIB-2 wins the molecular “tug of war”, the tumour becomes resistant to tamoxifen. The research is reported in the journal Nature.
Study leader Dr Jason Carroll said: “We knew that women developed resistance to tamoxifen, but previously our understanding of why this occurred could be compared with trying to fix a broken car without knowing how the engine worked.
“Now we understand how all the engine parts operate and we can try to think about ways to make repairs.”
Professor Sir David Lane, Cancer Research UK’s chief scientist, said: “Understanding why tamoxifen occasionally stops working allows us to identify new targets for drug development.”
Copyright Press Association 2008