Researchers from Ireland and Poland found that curcumin, a compound found in the popular Indian spice turmeric that gives curry powder its distinct yellow colour, killed oesophageal cancer cells in the lab via an unexpected cell-death mechanism that did not involve apoptosis or cell suicide.

Moreover, they found that the compound started killing cancer cells within 24 hours and the cells began to digest themselves.

The study was the work of lead author Dr Sharon McKenna at the Cork Cancer Research Centre, University College Cork (UCC) in Ireland, and colleagues, and appears in the 28 October issue of the British Journal of Cancer.

McKenna told the press that:

“These exciting results suggest that scientists could develop curcumin as a potential anti-cancer drug to treat oesophageal cancer.”

She explained that scientists have long known that natural compounds have potential therapeutic value in treating cancerous cells and they suspected that curcumin was one of them.

First author and UCC medical researcher Dr Geraldine O’Sullivan-Coyne, had been looking for new ways of killing resistant oesophageal cancer cells explained McKenna, and when she started using curcurmin she found the cells started to die using a cell signalling system that unexpectedly did not go via the apoptosis or cell suicide path.

Apoptosis is the most usual route by which faulty cells die: it is a cell suicide path triggered by proteins called caspases. But O’Sullivan-Coyne, McKenna and colleagues found that not only did the cells show no evidence of suicide, when they added a molecule that stops the caspases triggering apoptosis, it made no difference to the number of cells that died.

This strongly suggests that curcumin killed the cancer cells via another cell signalling path, said the researchers.

Oesophageal cancer is the seventh most common cause of death from cancer in Ireland, where it accounts for 350 deaths a year, around 4 per cent of all cancer deaths in Ireland. In the UK it kills around 7,800 people a year.

Fewer than 20 per cent of patients with oesophageal cancer live more than 5 years after diagnosis.

Professor Gerald O’Sullivan, who heads the Cork Cancer Research Centre at UCC said that this study opens the door to developing natural chemicals in turmeric as new treatments for oesophageal cancer.

“The incidence of oesophageal cancer has gone up by more than a half since the 70s, particularly in the Western world and this is thought to be linked to rising rates of obesity, alcohol intake and reflux disease, so finding ways to both treat and prevent this disease is extremely important,” he said, adding that:

“The development of natural compounds as chemo-preventative agents is also a very promising area of research.”

Dr Lesley Walker, director of cancer information at Cancer Research UK expressed a similar view to the BBC.

“Curcumin induces apoptosis-independent death in oesophageal cancer cells.”
G O’Sullivan-Coyne, G C O’Sullivan, T R O’Donovan, K Piwocka, S L McKenna
British Journal of Cancer, Published 28 October 2009.

Sources: UCC, BBC.

Written by: Catharine Paddock, PhD