Genetically Engineered Bugs Can Fight Cancer

GENETICALLY engineered bugs could provide a potent new weapon against cancer.

Scientists have managed to wipe out a variety of cancer cells using engineered E coli bugs, famous for causing food poisoning, in a laboratory setting.

They also managed to slow down the progression of skin cancer in mice.

The genetically engineered bacteria were used to smuggle a tumour- busting enzyme into cancer cells. Normally, the enzyme molecules would be barred from entering cells or broken down before they can take action.

E coli is found naturally in the human gut and only a few strains can cause food poisoning. The researchers modified the bugs to ensure they were harmless, and gave them the ability to penetrate human cell membranes. Once inside the cells, they release their cargo of therapeutic molecules.

Dr Georges Vassaux, lead researcher at the Cancer Research UK Molecular Oncology Unit at St Bartholomew’s Hospital, London, said: “It’s notoriously difficult to get some types of therapeutic molecule inside cancer cells, which is why we turned to living organisms to do the job for us.”

The enzyme works in conjunction with a powerful cancer drug, 6- MPDR. The drug cannot be activated until the enzyme is inside the cancer cells.

In experiments using a range of cancer cell lines, more than 90 per cent of the cells invaded by the bacteria were killed. Less than 15 per cent of cells that were not invaded died.

A follow-up study of mice with skin tumours showed that the same combination of genetically modified E coli bugs and anti-cancer drugs slowed down progress of the disease.

Dr Vassaux, whose research is reported in the on-line version of the journal Gene Therapy, added: ”

We also think that introducing bacteria into a patient’s body, albeit harmless, neutered ones, will provoke the immune system and help to direct it against the tumour.”