LONDON (Agence de Presse Medicale for Reuters Health) - Infecting tumours with genetically modified forms of Escherichia coli could be a safe and effective way of attacking cancer cells, scientists reported in this week’s online edition of Gene.
It is notoriously difficult to get some therapeutic molecules into cancer cells, so the Cancer Research UK team turned to living organisms to deliver an enzyme called purine nucleoside phosphorylase. This turns the inactive prodrug 6-MPDR into a potent cancer treatment.
The method involved inserting a gene called invasin into E. coli so that the bacterium could penetrate the outer membrane of cancer cells. The bacterium also received a second gene, called listeriolysin O, to protect their cargo until safely inside the cells.
When researchers treated mouse tumours with the recombinant therapy, they found that the treatment seemed to slow the cancer’s progression and cause large numbers of tumour cells to die.
Dr Georges Vassaux, lead researcher at the Cancer Research UK Molecular Oncology Unit in London, said in a statement: “We may be able to use the bacterial system to reach as many cancer cells as possible with drug-activating enzymes. Subsequent prodrug treatment could then efficiently attack tumours while leaving healthy tissue alone--minimising side effects.
“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. So we may get the advantage of an immunotherapeutic effect, as well as the specific action of the prodrug treatment.”
Gene Therapy advance online publication, April 22, 2004.
MeSH Headings:Behavioral Sciences: Biological Therapy: Behavioral Disciplines and Activities: Drug and Narcotic Control: Drug Screening: Health Care Economics and Organizations: Evaluation Studies: Genetic Engineering: Genetic Techniques: Health Occupations: Health Services Administration: Legislation: Legislation, Drug: Investigative Techniques: Organization and Administration: Pharmacy Administration: Quality of Health Care: Social Control, Formal: Social Sciences: Sociology: Therapeutics: Gene Therapy: Drugs, Investigational: Drug Approval: Health Care Quality, Access, and Evaluation: Health Care Evaluation Mechanisms: Analytical, Diagnostic and Therapeutic Techniques and Equipment: Anthropology, Education, Sociology and Social Phenomena: Biological Sciences: Health Care: Psychiatry and PsychologyCopyright © 2002 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.