Researchers investigating the role of cannabis in cancer therapy reveal it has the potential to destroy leukaemia cells, in a paper published in the March 2006 edition of Letters in Drug Design & Discovery.

Led by Dr Wai Man Liu, at Barts and the London, Queen Mary's School of Medicine and Dentistry, the team has followed up on their findings of 2005 which showed that the main active ingredient in cannabis, tetrahydrocannabinol, or THC, has the potential to be used effectively against some forms of cancer. Dr Liu has since moved to the Institute of Cancer in Sutton where he continues his work into investigating the potential therapeutic benefit of new anti-cancer agents.

It has previously been acknowledged that cannabis-based medicines have merit in the treatment of cancer patients as a painkiller; appetite stimulant and in reducing nausea, but recently evidence has been growing of its potential as an anti-tumour agent. The widely reported psychoactive side effects and consequent legal status of cannabis have, however, complicated its use in this capacity. Although THC and its related compounds have been shown to attack cancer cells by interfering with important growth-processing pathways, it has not hitherto been established exactly how this is achieved. Now Dr Liu and his colleagues, using highly sophisticated microarray technology - allowing them to simultaneously detect changes in more than 18,000 genes in cells treated with THC - have begun to uncover further the existence of crucial processes through which THC can kill cancer cells and potentially promote survival.

Whilst leukaemia treatment is on the whole successful, some people cannot be treated with conventional therapy - 25 per cent of children with leukaemia fail to respond to traditional treatment leaving their prognosis outcome poor. Dr Liu's research findings provide a crucial first step towards the development of new therapies that can eradicate a deadly disease which affects millions of children and adults worldwide.

Dr Liu said: "It is important to stress that these cannabis-like substances are far removed from the cannabis that is smoked. These novel compounds have been specifically designed to be free of the psychoactive features, whilst maintaining anti-cancer action. Ultimately, understanding the fundamental mechanisms of these compounds will provide us with insights into developing new drugs that can be used to effectively treat cancers."