Cancer Research UK-funded scientists find way to eliminate leukaemia stem cells

In collaboration with Adfero

Scientists at King's College London are working on a way of eliminating leukaemic 'stem cells' to prevent leukaemia from returning after a patient has received treatment.

Cancer stem cells are rogue cells that are resistant to radiotherapy and chemotherapy and are thought to drive the growth of many cancers, including leukaemia.

Now, Cancer Research UK-funded researchers at King's have identified a possible way to eliminate these leukaemic stem cells, although this has so far only been achieved in laboratory models, not in humans.

The researchers focused on cells from a particular type of leukaemia, which involves faults in a gene called MLL and accounts for about 70 per cent of infant leukaemias and ten per cent of adult leukaemias.

They found that loss of a protein called Bmi1 - which is known to be important for the survival and proliferation of various cancer stem cells - was not enough to eliminate cancer stem cells in MLL leukaemia.

However, when both Bmi1 and another protein called Hoxa9 were suppressed at the same time, the leukaemic stem cells lost their ability to induce MLL leukaemia.

The findings, which are published in the journal Cell Stem Cell, suggest that by targeting both of these proteins, it may be possible to prevent this type of leukaemia from returning.

Professor Eric So, head of the leukaemia and stem cell biology group at King's, said: "These findings take us a step forward in our understanding of how this devastating disease can return in patients after they have received the standard treatment.

"Now we know that leukaemic stem cells in certain types of leukaemia, such as MLL, can survive and proliferate independently of the Bmi1 protein, we need to consider more carefully the future of stem cell therapy to treat the disease. It's not as easy as people originally thought it might be."

The team now hope to work out how the Bmi1 and Hoxa9 proteins sustain the growth of cancer cells in order to develop an effective treatment.

Professor Peter Johnson, Cancer Research UK's chief clinician, said: "This study builds on previous Cancer Research UK-funded work trying to pinpoint the molecules responsible for driving the development of MLL-related leukaemia stem cells.

"Cancer stem cells appear to be more resistant to radiotherapy and chemotherapy than the other leukaemia cells, so understanding how they originate - and how we can kill them - will be a major step in being able to help even more people survive leukaemia in future."

References

  • Smith L-L et al. Functional Crosstalk between Bmi1 and MLL/Hoxa9 Axis in Establishment of Normal Hematopoietic and Leukemic Stem Cells. Cell Stem Cell 8, 649–662. DOI: 10.1016/j.stem.2011.05.004