It might be possible to combat early-stage cervical cancer simply by applying a gel to a woman’s cervix, rather than removing abnormal cells surgically. The team developing the gel hopes to carry out clinical trials in the UK soon, and similar gels could one day be developed to treat other cancers on accessible surfaces.Cervical cancer kills almost a quarter of a million women worldwide each year. It is caused by a common sexually transmitted virus, the human papilloma virus (HPV).Occasionally, the viral DNA inserts itself into the genome of cells on the surface of the cervix, boosting production of two viral proteins, E6 and E7. These prevent cell suicide and can turn cells cancerous.Several research groups have shown that if production of these proteins is blocked, cervical cancer cells growing in a dish commit suicide, while normal cells are unharmed. One way to block the proteins is to use RNA interference, which exploits an ancient natural defence mechanism against viruses. If “short interfering RNAs” (siRNAs) – small pieces of RNA matching part of a specific gene – are introduced into cells, all RNA copies of that gene will be blocked before any protein can be made.
