Targeting stem cell molecule blocks bowel cancer in mice
Blocking a molecule in tumour-fuelling stem cells could offer a new way to treat bowel cancer, a Canadian study has shown.
The researchers found that a molecule called BMI-1 is crucial in helping a small subset of tumour cells to grow, and that blocking BMI-1 stops the growth of bowel cancers in mice.
"Pinpointing what makes some cancers return is a major challenge and research looking at cancer stem cells could provide useful clues" - Dr Simon Buczacki, Cancer Research UK
Cancer stem cells are rogue cells that can be resistant to radiotherapy and chemotherapy and are thought to drive the growth of some cancers, including bowel cancer.
Preventing these cells from renewing could offer new opportunities to tackle the disease.
The researchers from the Princess Margaret Cancer Centre focused on BMI-1 because it is already thought to regulate stem cells in other types of cancer.
In their study, published in the journal Nature Medicine, they found that disarming the gene that encodes BMI-1 reduced how much bowel cancer cells grew in the lab.
By making a compound that blocked BMI-1, the researchers were then able to reduce the growth of human bowel cancer cells in mice.
Dr John Dick, who helped lead the study, said: "When we blocked the BMI-1 pathway, the stem cells were unable to self-renew, which resulted in long-term and irreversible impairment of tumour growth."
Sixty-five per cent of bowel cancer patients produce the BMI-1 molecule, according Dr Catherine O'Brien, who was also involved in the study.
And she believes this knowledge could translate into first-in-human trials to provide more personalised treatment for bowel cancer.
Dr Simon Buczacki, a Cancer Research UK expert in cancer stem cells, welcomed the study but said further research is needed to assess whether the same process occurs in primary human bowel cancers.
He said: "Pinpointing what makes some cancers return is a major challenge and research looking at cancer stem cells could provide useful clues. This early study using mice nicely demonstrates how blocking a marker of cancer stem cells could stop the growth of bowel cancer, but more work is needed."
Dr Buczacki added that it will be crucial to test what affects the blocking of this marker in people might have on normal cells.
He said this knowledge will be important in reducing side-effects in any potential new drugs that may emerge from the research.
Copyright Press Association 2013