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Researchers track down the genes that could put the brakes on breast cancer.

February 22, 1999

Normally, old or damaged cells are told to stop dividing and 'self-destruct' to prevent any mutations being duplicated and growing into tumours. But cancer cells usually ignore these messages and become 'immortal' allowing them to continue multiplying indefinitely and out of control.
Scientists already know that an enzyme called 'telomerase' is one of the factors responsible for protecting cancer cells from their natural ageing process. But this latest research is believed to be the first time that scientists have been able to find a way of 'switching off' this enzyme.
These findings - published in the latest issue of the 'Journal of the National Cancer Institute' (Article: JNCI, volume 91, number 1, pgs. 37 - 45, Jan 6 1999) - could lead to the development of innovative new anti-cancer drugs and help improve the treatment of breast cancer which currently kills around 14,000 women in the UK each year.
Prof Newbold, Head of the Department of Biological Sciences at Brunel University, explains: "All healthy cells in the body have an 'in-built' alarm clock which instructs them to stop dividing and die when they reach a certain age. But cancer cells are able to bypass this mechanism and continue multiplying out of control."
He adds: "We already know that telomerase is active in around 85 per cent of cancers and is probably responsible for kick-starting the process that protects cancer cells from dying. However, our latest research has finally been able to pinpoint a new way to potentially de-activate this rogue enzyme."
Prof Newbold and his team carried out an extensive search looking for ways to 'switch off' the gene which produces the telomerase enzyme.
In lab tests, groups of healthy genes [carried on chromosomes] were transferred into breast tumour tissue in a bid to find out which combination could potentially stop the gene (which produces telomerase) from working.
Prof Newbold says: "These findings show we have now successfully identified 'chromosome 3' as the specific group of genes which has the ability to stop the further production of telomerase in breast tumours. In addition, by using advanced genetic techniques we have also been able to map the gene responsible to a small region of the chromosome.
"The introduction of a normal copy of chromosome 3 into these breast cancer cells will cause them to regain their normal ageing process and die."
He adds: "An international race to find the natural inhibitor to telomerase has been running for many years and this latest discovery has really put UK scientists a step ahead."
Scientists will now be working on ways to mimic this group of genes which effectively control the natural ageing process of cells. It is hoped this will lead to the synthetic production of anti-cancer drugs to block telomerase and therefore halt the growth of human tumours.
Director General of the Cancer Research Campaign Prof Gordon McVie says: "This research really is a major step forward in the hunt for new and improved treatments for breast cancer patients. Finding new ways to combat the 'immortality' of cancer cells is fast becoming a vital part of cancer research and is proving crucial to the development of future anti-cancer treatments.
"The findings are also another example of how gene therapy is being developed to target tumours without causing damage to healthy cells as well."
He adds: "This research is particularly exciting as it opens new doors in the fight against breast cancer - the biggest cause of cancer death in British women today."