LONDON (Reuters) - British scientists said on Tuesday they had developed a treatment that transports anti-cancer genes selectively into cancer cells using nanotechnology.

The therapy has so far only been tried out on mice, but the aim is to test it in humans within two years.

If it works in people, it would provide a highly targeted mechanism for delivering cancer-fighting gene therapy.

Cancer Research UK's Andreas Schatzlein, based at the School of Pharmacy in London, said it was the first time that nanoparticles had been shown to target tumors in such a selective way.

Schatzlein and colleagues packaged anti-cancer genes in very small particles that are only taken up by cancer cells, leaving healthy cells unharmed. Once taken up, the genes force the cell to produce proteins that can kill the cancer.

The approach may be particularly useful for people with cancers that are inoperable because they are close to vital organs such as the brain or lungs.

"We hope this therapy will be used to treat cancer patients in clinical trials in a couple of years," Schatzlein said in a statement.

Results of his team's study were published online in the journal Cancer Research.

Gene therapy is viewed as promising area of research for treating cancer and other diseases, but getting genes to exactly the right place in the body is a major challenge.