Major breakthrough in cancer research as scientists unlock the secrets of crucial enzyme

A major breakthrough in cancer research could lead to the creation of 'one-size-fits-all' drugs capable of tackling almost all forms of the disease.

Scientists have unravelled the secrets of an enzyme called telomerase that makes cancer cells immortal.

This allows them to multiply uncontrollably and cause disease.

The landmark discovery paves the way for the creation of drugs that block the enzyme, stopping tumour growth.

With telomerase at work in almost all human cancers, such a drug or family of drugs could have a major impact in the treatment of the disease which affects almost 300,000 Britons a year and kills someone every four minutes.

Liz Baker, of charity Cancer Research UK, said: 'This is a crucial part of the puzzle in understanding how telomerase works.

'Fundamental research like this may help scientists to design drugs that block telomerase and could potentially be used to treat a wide range of cancers.'

The implications of the US research do not end there, with new anti-ageing treatments or better drugs for age-related diseases also possibly on the cards, the journal Nature reports.

The researchers from the Wistar Institute in Philadelphia, have deciphered the structure of a key part of telomerase.

In healthy cells, the enzyme is all but switched off, and the cells multiply a set number of times before dying - a key part of the ageing process.

But in up to 90 per cent of cancers, the enzyme is activated, allowing runaway cell division and tumour growth.

Solving the compound's structure will allow scientists to design drugs that deactivate the enzyme and so halt the disease in its tracks.

The targeting of cancerous cells should mean such medicines would be free of the side-effects such as the pain, nausea and hair loss associated with conventional treatments.

Previous attempts to make telomerase-blocking drugs have been thwarted by lack of knowledge about the enzyme.

Study leader Dr Emmanuel Skordalakes described the breakthrough as 'extremely exciting'.

'Telomerase is an ideal target for chemotherapy because it is active in almost all human tumours, but inactive in most normal cells,' he said.

'That means a drug that deactivates telomerase would likely work against all cancers, with few side effects.'

Unravelling the mysteries of telomerase could also pave the way for therapies that combat ageing and age-related diseases.

Switching on telomerase in a controlled, safe way, could theoretically produce younger, healthier and longer living tissue.

The researchers concluded: 'Because telomerase has a critical role in both cancer and ageing, these findings could potentially assist our efforts to identify and develop inhibitors and/or activators of this enzyme for the treatment of cancer and ageing, respectively.'

But the enzyme's structure is complex and any drugs that are designed will have to go through many years of laboratory, animal and human testing before they reach the pharmacy shelves.