Scientists have discovered a master switch which can turn off the growth of cancerous cells.

Ground-breaking research exposed mutations in one specific cancer gene which can control how parts of genes slot together to create proteins.

These proteins make blood vessels to speed up cancer cell growth, delivering oxygen and sugar to the tumour.

The proteins are vascular growth factors like VEGF - the target for anti-cancer drug Avastin.

Making the proteins requires the slotting together of different parts of genes, a process called splicing - controlled by the mutated cancer gene.

Researchers at the University of Bristol and the University of the West of England found they could block the master switch by using new drugs.

This prevented blood vessel growth and stopped the growth of cancers.

Dr Michael Ladomery, who spearheaded the work from UWE Bristol, said the halting of the growth had only been tried in models but had "potential".

He said: "The research clearly demonstrates that it may be possible to block tumour growth by targeting and manipulating alternative splicing in patients, adding to the increasingly wide armoury of potential anti-cancer therapies."

The research, published in journal Cancer Cell on Monday, revealed how cancer cells gain the nutrients they need by producing proteins that make blood vessels grow.

They make the proteins by slotting together different part of genes - called splicing.

Scientists found mutations in one specific cancer gene  can control how splicing is balanced, allowing a master switch in the cell to be turned off.

This master switch of splicing makes cancer cells grow faster, and blood vessels to grow more quickly, as they alter how VEGFs - the proteins - are put together.

In experimental models, researchers found that using new drugs blocked the master switch, preventing blood vessel growth and halting the growth of cancers.

Professor David Bates, who led the team from the University of Bristol's School of Physiology and Pharmacology said that the discovery could spark new cancer drugs.

He said: "This enables us to develop new classes of drugs that target blood vessel growth in cancer and other diseases like blindness and kidney disease."

The work started on kidney cancer, with scientists examining tissues that had been removed from patients during surgery at Southmead Hospital, Bristol, to use in research.

Professor Moin Saleem, Consultant Paediatric Nephrologist, who lab helped to create the cells used, added: "We are really grateful to the patients who allowed their cells to be used in this research, as we hope it will eventually help the development of new drugs."

The research was sponsored by a UWE Bristol Faculty PhD studentship, which funded Elianna Amin, the first author on the paper.

It was also supported by University of Bristol grants from the British Heart Foundation, Cancer Research UK, Wellcome Trust, Medical Research Council, Fight for Sight and the Skin Cancer Research Fund.