New technique could speed up research into cancer stem cells
Scientists at Oxford University, funded by Cancer Research UK, have discovered a way to investigate cancer stem cells more efficiently in the laboratory.
The research, published in Proceedings of the National Academy of Science, outlines a technique that should allow scientists to grow cancer stem cells from previously-existing cell lines, rather than from patient samples.
Currently a key area of cancer research, cancer stem cells are thought to be able to generate new cells and differentiate into various types of cells. It is these properties that supposedly enable them to initiate tumours and drive their growth.
In addition, cancer stem cells seem to be more resistant to radiotherapy and chemotherapy than other cells, meaning that they might not be targeted by current treatments, and may be the reason why cancer often comes back.
Many researchers therefore believe that an increased understanding of cancer stem cells would help to improve anti-cancer therapies.
Dr Trevor Yeung, from Oxford University's Weatherall Institute of Molecular Medicine, likened the importance of targeting cancer stem cells to tackling unwanted plant growth.
"It's like trying to weed the garden," he explained. "It's no good just chopping off the leaves, we need to target the roots to stop the weeds coming back.
"If we could target treatments against these cells specifically, we should be able to eradicate the cancer completely."
However, although evidence for their role in cancer development and growth is mounting, their precise nature is elusive. Cancer stem cells have proved notoriously difficult to study because they are hard to identify and separate out from other cells.
Until now, scientists have only been able to identify cancer stem cells by analysing tumour samples taken from patients - a cumbersome process that has limited the pace of progress.
Now, the Oxford team have discovered a way to obtain samples of cancer stem cells from bowel cancer cell lines and maintain them in the laboratory.
If applicable to cell lines from other cancer types, the advance should speed up studies on cancer stem cells and help to improve researchers' understanding of the way in which they drive the growth of tumours. The development could even lead to new drugs targeted at these cells.
In addition to the new technique, the paper also casts doubt on the idea that stem cells only make up a small proportion of cells in a given tumour.
Instead, the team's results suggest that different tumours contain differing amounts of stem cells - and that the higher the proportion of stem cells, the more aggressive the tumour.
Henry Scowcroft, science information manager at Cancer Research UK, welcomed the new study. "Stem cells are a hot topic in cancer research, but they're very difficult to study and there's a lot still to learn about them," he said.
"This interesting paper from Cancer Research UK-funded scientists should speed up progress in this area, by making stem cells easier to grow and study in the lab, accelerating our progress in beating cancer."
- Yeung TM et al, Cancer stem cells from colorectal cancer-derived cell lines, PNAS, Jan 2009 (link tbc)