German researchers yesterday proposed a ''Trojan horse'' method of attacking cancer - sneaking virus impersonators into the human body, which prompted an immune response that attacked tumours.
The method, which is said to be the latest advance in immunotherapy, had so far been tested on only three people. It aims to stimulate the body's own immune system against disease.
The lab made, Trojan horse is made from nanoparticles containing cancer RNA, a form of genetic coding, enclosed by a fatty acid membrane.
The particles are injected into patients to simulate a viral infection. The dendritic cells of the immune system decode the RNA embedded in the nanoparticles, which triggers the production of cancer antigens.
The antigens then activate cancer-fighting T cells, which attack tumours.
After the treatment had been tried out in mice, three people with advanced skin cancer were given low doses of the treatment, in the first step of a long process to test new drugs on humans.
The journal Nature reported that all developed a ''strong'' immune response.
The RNA triggered the kind of immune response normally with which the body fights viruses - only in this case, the targets were cancer cells.
The German research raises the possibility of a vaccine that could be tailored to work against any form of cancer, or even new versions of a disease that evolved as it progressed within the same patient, according to experts.
Writing in the journal Nature, the scientists led by professor Ugur Sahin, from Johannes Gutenberg University in Mainz, Germany, concluded: "Virtually any tumour antigen (protein) can be encoded by RNA.
''Thus, the nanoparticulate RNA immunotherapy approach introduced here may be regarded as a universally applicable novel vaccine class for cancer immunotherapy."
RNA is a molecular cousin of DNA and transfers genetic code instructions to protein-making machinery in cells.