Scientists have paved the way for a new cancer therapy by trying to halt the process essential for tumour growth.

The Australian team revealed they could halt the process of fast growth of blood vessels (angiogenesis), essential in helping tumours grow and spread, by switching off a master gene.

Turning off the gene RGS5 makes vessel growth normal and gives the immune system a better chance of getting to the tumour and destroying it, they said.

The discovery was made in mice, but the researchers and other cancer experts said it offers hope as a bold new therapy if the process can be replicated in humans.

Prof Ruth Ganss of the Western Australian Institute for Medical Research said, ''By understanding what is actually going on in the tumour itself, the ultimate hope is that we'll be able to work on making current therapeutic approaches even more successful and reducing their side effects.'' Explaining angiogenesis, she said, ''It's the uncontrolled growth of blood vessels and the formation of abnormal blood vessels inside tumours that 'feed' them, allowing them to grow and stopping the immune system from wiping out the tumour.'' ''What we've shown is that RGS5 is a master gene in angiogenesis and when it is removed, angiogenesis reverses and the blood vessels in tumours appear more normal,'' the Age quoted her as saying.

Prof Ganss said this normalisation changed the tumour environment in a way that improved immune cell entry, meaning tumours could be destroyed.