Of Crocuses and Cancer
Every now and then, media headlines become excited by a new potential ‘cure’ for cancer. Usually, this excitement stems from the results of very early research, which often involves a vegetable. Tomatoes, broccoli, cabbage, sprouts and beetroot have all had their turn in the spotlight over the years.
This week, it wasn’t a vegetable that commanded the media’s attention (although this morning I did come across a piece touting the benefits of spicy broccoli for fighting cancer); instead, the flower, the British Autumn crocus, stole the spotlight following the release of a press statement from the UK’s University of Bradford. According to the statement, researchers have created a drug that has the potential to find and destroy solid tumours, regardless of cancer type.
The drug’s key active agent is based on colchicine, a natural compound that was derived from the crocus. Most media headlines have sensationalised the research (examples include: Tumors effectively cured with crocus drug, Crocus drug that can kill tumours in one treatment with minimal side effects and Flower-powered ‘smart bomb’ to beat cancer, scientists say), but when you look beyond the hype, there’s some intriguing science.
Colchicine is well-known for its anti-cancer properties, but is highly toxic against normal tissues in the body. The researchers, however, have designed a delivery system that prevents colchicine from being active around the rest of the body where it could damage normal cells. The release of colchicine is triggered by an enzyme from a family of proteases called Matrix Metalloproteinases (MMPs), which is only usually present in high amounts in tumours.
“One role of this particular MMP in cancers is to dig a path for the tumour to grow bigger and develop new blood vessels that will help nourish the tumour,” Professor Laurence Patterson, Director of Bradford’s Institute for Cancer Therapeutics (ICT), explained in a statement. “Our novel delivery method uses the presence of this active MMP to activate the drug which attacks and breaks down cancer blood vessels, destroying the tumour’s lifeline.”
Five different types of cancer have been tested in the laboratory using mice — breast, colon, lung, sarcoma and prostate. According to the researchers, in one study, half the mice showed complete tumour remission after a single dose. The team is now in discussion with a funder to take the drug through the final stages of preclinical assessment, after which clinical trials are planned to start at St James’s University Hospital in Leeds.
Back to reality
The research (and the accompanying media sensationalism) has caused a massive stir, but the UK’s Cancer Research was charity was quick to point out in a detailed blog that the research is a long way from curing human cancers. There’s also no guarantee that it will ever be possible to translate the findings into humans (see my related blog post A Rat is Not a Human!).
Cancer Research also points out something else; the press release seems to be based on peer-reviewed work that the researchers published in July 2010. “As far as we’re aware, the team haven’t published any new results since their 2010 paper,” said Cancer Research.
It’s not all disappointing news, however. The research is still a step forward in the fight against cancer and Cancer Research admits that the research is intriguing, although it does remain cautious in its outlook.
“The researchers’ results so far are impressive, but they’re just one of several hundreds of similar intricate approaches taken to tackle cancer by researchers around the globe, which are generally referred to as ‘enzyme-prodrug therapy’, and involve activating a harmless form of a drug near or in a tumour… Overall it’s fair to say that this kind of approach is still at a relatively early stage, although the Bradford results are certainly impressive, and their beauty is in their relative simplicity.”
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